In bpf_seq_printf() helper, when user specified a "%s" in the
format string, strncpy_from_unsafe() is used to read the actual string
to a buffer. The string could be a format string or a string in
the kernel data structure. It is really unlikely that the string
will reside in the user memory.
This is different from Commit b2a5212fb6 ("bpf: Restrict bpf_trace_printk()'s %s
usage and add %pks, %pus specifier") which still used
strncpy_from_unsafe() for "%s" to preserve the old behavior.
If in the future, bpf_seq_printf() indeed needs to read user
memory, we can implement "%pus" format string.
Based on discussion in [1], if the intent is to read kernel memory,
strncpy_from_unsafe_strict() should be used. So this patch
changed to use strncpy_from_unsafe_strict().
[1]: https://lore.kernel.org/bpf/20200521152301.2587579-1-hch@lst.de/T/
Fixes: 492e639f0c ("bpf: Add bpf_seq_printf and bpf_seq_write helpers")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/bpf/20200529004810.3352219-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit adds a new MPSC ring buffer implementation into BPF ecosystem,
which allows multiple CPUs to submit data to a single shared ring buffer. On
the consumption side, only single consumer is assumed.
Motivation
----------
There are two distinctive motivators for this work, which are not satisfied by
existing perf buffer, which prompted creation of a new ring buffer
implementation.
- more efficient memory utilization by sharing ring buffer across CPUs;
- preserving ordering of events that happen sequentially in time, even
across multiple CPUs (e.g., fork/exec/exit events for a task).
These two problems are independent, but perf buffer fails to satisfy both.
Both are a result of a choice to have per-CPU perf ring buffer. Both can be
also solved by having an MPSC implementation of ring buffer. The ordering
problem could technically be solved for perf buffer with some in-kernel
counting, but given the first one requires an MPSC buffer, the same solution
would solve the second problem automatically.
Semantics and APIs
------------------
Single ring buffer is presented to BPF programs as an instance of BPF map of
type BPF_MAP_TYPE_RINGBUF. Two other alternatives considered, but ultimately
rejected.
One way would be to, similar to BPF_MAP_TYPE_PERF_EVENT_ARRAY, make
BPF_MAP_TYPE_RINGBUF could represent an array of ring buffers, but not enforce
"same CPU only" rule. This would be more familiar interface compatible with
existing perf buffer use in BPF, but would fail if application needed more
advanced logic to lookup ring buffer by arbitrary key. HASH_OF_MAPS addresses
this with current approach. Additionally, given the performance of BPF
ringbuf, many use cases would just opt into a simple single ring buffer shared
among all CPUs, for which current approach would be an overkill.
Another approach could introduce a new concept, alongside BPF map, to
represent generic "container" object, which doesn't necessarily have key/value
interface with lookup/update/delete operations. This approach would add a lot
of extra infrastructure that has to be built for observability and verifier
support. It would also add another concept that BPF developers would have to
familiarize themselves with, new syntax in libbpf, etc. But then would really
provide no additional benefits over the approach of using a map.
BPF_MAP_TYPE_RINGBUF doesn't support lookup/update/delete operations, but so
doesn't few other map types (e.g., queue and stack; array doesn't support
delete, etc).
The approach chosen has an advantage of re-using existing BPF map
infrastructure (introspection APIs in kernel, libbpf support, etc), being
familiar concept (no need to teach users a new type of object in BPF program),
and utilizing existing tooling (bpftool). For common scenario of using
a single ring buffer for all CPUs, it's as simple and straightforward, as
would be with a dedicated "container" object. On the other hand, by being
a map, it can be combined with ARRAY_OF_MAPS and HASH_OF_MAPS map-in-maps to
implement a wide variety of topologies, from one ring buffer for each CPU
(e.g., as a replacement for perf buffer use cases), to a complicated
application hashing/sharding of ring buffers (e.g., having a small pool of
ring buffers with hashed task's tgid being a look up key to preserve order,
but reduce contention).
Key and value sizes are enforced to be zero. max_entries is used to specify
the size of ring buffer and has to be a power of 2 value.
There are a bunch of similarities between perf buffer
(BPF_MAP_TYPE_PERF_EVENT_ARRAY) and new BPF ring buffer semantics:
- variable-length records;
- if there is no more space left in ring buffer, reservation fails, no
blocking;
- memory-mappable data area for user-space applications for ease of
consumption and high performance;
- epoll notifications for new incoming data;
- but still the ability to do busy polling for new data to achieve the
lowest latency, if necessary.
BPF ringbuf provides two sets of APIs to BPF programs:
- bpf_ringbuf_output() allows to *copy* data from one place to a ring
buffer, similarly to bpf_perf_event_output();
- bpf_ringbuf_reserve()/bpf_ringbuf_commit()/bpf_ringbuf_discard() APIs
split the whole process into two steps. First, a fixed amount of space is
reserved. If successful, a pointer to a data inside ring buffer data area
is returned, which BPF programs can use similarly to a data inside
array/hash maps. Once ready, this piece of memory is either committed or
discarded. Discard is similar to commit, but makes consumer ignore the
record.
bpf_ringbuf_output() has disadvantage of incurring extra memory copy, because
record has to be prepared in some other place first. But it allows to submit
records of the length that's not known to verifier beforehand. It also closely
matches bpf_perf_event_output(), so will simplify migration significantly.
bpf_ringbuf_reserve() avoids the extra copy of memory by providing a memory
pointer directly to ring buffer memory. In a lot of cases records are larger
than BPF stack space allows, so many programs have use extra per-CPU array as
a temporary heap for preparing sample. bpf_ringbuf_reserve() avoid this needs
completely. But in exchange, it only allows a known constant size of memory to
be reserved, such that verifier can verify that BPF program can't access
memory outside its reserved record space. bpf_ringbuf_output(), while slightly
slower due to extra memory copy, covers some use cases that are not suitable
for bpf_ringbuf_reserve().
The difference between commit and discard is very small. Discard just marks
a record as discarded, and such records are supposed to be ignored by consumer
code. Discard is useful for some advanced use-cases, such as ensuring
all-or-nothing multi-record submission, or emulating temporary malloc()/free()
within single BPF program invocation.
Each reserved record is tracked by verifier through existing
reference-tracking logic, similar to socket ref-tracking. It is thus
impossible to reserve a record, but forget to submit (or discard) it.
bpf_ringbuf_query() helper allows to query various properties of ring buffer.
Currently 4 are supported:
- BPF_RB_AVAIL_DATA returns amount of unconsumed data in ring buffer;
- BPF_RB_RING_SIZE returns the size of ring buffer;
- BPF_RB_CONS_POS/BPF_RB_PROD_POS returns current logical possition of
consumer/producer, respectively.
Returned values are momentarily snapshots of ring buffer state and could be
off by the time helper returns, so this should be used only for
debugging/reporting reasons or for implementing various heuristics, that take
into account highly-changeable nature of some of those characteristics.
One such heuristic might involve more fine-grained control over poll/epoll
notifications about new data availability in ring buffer. Together with
BPF_RB_NO_WAKEUP/BPF_RB_FORCE_WAKEUP flags for output/commit/discard helpers,
it allows BPF program a high degree of control and, e.g., more efficient
batched notifications. Default self-balancing strategy, though, should be
adequate for most applications and will work reliable and efficiently already.
Design and implementation
-------------------------
This reserve/commit schema allows a natural way for multiple producers, either
on different CPUs or even on the same CPU/in the same BPF program, to reserve
independent records and work with them without blocking other producers. This
means that if BPF program was interruped by another BPF program sharing the
same ring buffer, they will both get a record reserved (provided there is
enough space left) and can work with it and submit it independently. This
applies to NMI context as well, except that due to using a spinlock during
reservation, in NMI context, bpf_ringbuf_reserve() might fail to get a lock,
in which case reservation will fail even if ring buffer is not full.
The ring buffer itself internally is implemented as a power-of-2 sized
circular buffer, with two logical and ever-increasing counters (which might
wrap around on 32-bit architectures, that's not a problem):
- consumer counter shows up to which logical position consumer consumed the
data;
- producer counter denotes amount of data reserved by all producers.
Each time a record is reserved, producer that "owns" the record will
successfully advance producer counter. At that point, data is still not yet
ready to be consumed, though. Each record has 8 byte header, which contains
the length of reserved record, as well as two extra bits: busy bit to denote
that record is still being worked on, and discard bit, which might be set at
commit time if record is discarded. In the latter case, consumer is supposed
to skip the record and move on to the next one. Record header also encodes
record's relative offset from the beginning of ring buffer data area (in
pages). This allows bpf_ringbuf_commit()/bpf_ringbuf_discard() to accept only
the pointer to the record itself, without requiring also the pointer to ring
buffer itself. Ring buffer memory location will be restored from record
metadata header. This significantly simplifies verifier, as well as improving
API usability.
Producer counter increments are serialized under spinlock, so there is
a strict ordering between reservations. Commits, on the other hand, are
completely lockless and independent. All records become available to consumer
in the order of reservations, but only after all previous records where
already committed. It is thus possible for slow producers to temporarily hold
off submitted records, that were reserved later.
Reservation/commit/consumer protocol is verified by litmus tests in
Documentation/litmus-test/bpf-rb.
One interesting implementation bit, that significantly simplifies (and thus
speeds up as well) implementation of both producers and consumers is how data
area is mapped twice contiguously back-to-back in the virtual memory. This
allows to not take any special measures for samples that have to wrap around
at the end of the circular buffer data area, because the next page after the
last data page would be first data page again, and thus the sample will still
appear completely contiguous in virtual memory. See comment and a simple ASCII
diagram showing this visually in bpf_ringbuf_area_alloc().
Another feature that distinguishes BPF ringbuf from perf ring buffer is
a self-pacing notifications of new data being availability.
bpf_ringbuf_commit() implementation will send a notification of new record
being available after commit only if consumer has already caught up right up
to the record being committed. If not, consumer still has to catch up and thus
will see new data anyways without needing an extra poll notification.
Benchmarks (see tools/testing/selftests/bpf/benchs/bench_ringbuf.c) show that
this allows to achieve a very high throughput without having to resort to
tricks like "notify only every Nth sample", which are necessary with perf
buffer. For extreme cases, when BPF program wants more manual control of
notifications, commit/discard/output helpers accept BPF_RB_NO_WAKEUP and
BPF_RB_FORCE_WAKEUP flags, which give full control over notifications of data
availability, but require extra caution and diligence in using this API.
Comparison to alternatives
--------------------------
Before considering implementing BPF ring buffer from scratch existing
alternatives in kernel were evaluated, but didn't seem to meet the needs. They
largely fell into few categores:
- per-CPU buffers (perf, ftrace, etc), which don't satisfy two motivations
outlined above (ordering and memory consumption);
- linked list-based implementations; while some were multi-producer designs,
consuming these from user-space would be very complicated and most
probably not performant; memory-mapping contiguous piece of memory is
simpler and more performant for user-space consumers;
- io_uring is SPSC, but also requires fixed-sized elements. Naively turning
SPSC queue into MPSC w/ lock would have subpar performance compared to
locked reserve + lockless commit, as with BPF ring buffer. Fixed sized
elements would be too limiting for BPF programs, given existing BPF
programs heavily rely on variable-sized perf buffer already;
- specialized implementations (like a new printk ring buffer, [0]) with lots
of printk-specific limitations and implications, that didn't seem to fit
well for intended use with BPF programs.
[0] https://lwn.net/Articles/779550/
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200529075424.3139988-2-andriin@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Often it is useful when applying policy to know something about the
task. If the administrator has CAP_SYS_ADMIN rights then they can
use kprobe + networking hook and link the two programs together to
accomplish this. However, this is a bit clunky and also means we have
to call both the network program and kprobe program when we could just
use a single program and avoid passing metadata through sk_msg/skb->cb,
socket, maps, etc.
To accomplish this add probe_* helpers to bpf_base_func_proto programs
guarded by a perfmon_capable() check. New supported helpers are the
following,
BPF_FUNC_get_current_task
BPF_FUNC_probe_read_user
BPF_FUNC_probe_read_kernel
BPF_FUNC_probe_read_user_str
BPF_FUNC_probe_read_kernel_str
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/159033905529.12355.4368381069655254932.stgit@john-Precision-5820-Tower
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
- Add AMD Fam17h RAPL support
- Introduce CAP_PERFMON to kernel and user space
- Add Zhaoxin CPU support
- Misc fixes and cleanups
Tooling changes:
perf record:
- Introduce --switch-output-event to use arbitrary events to be setup
and read from a side band thread and, when they take place a signal
be sent to the main 'perf record' thread, reusing the --switch-output
code to take perf.data snapshots from the --overwrite ring buffer, e.g.:
# perf record --overwrite -e sched:* \
--switch-output-event syscalls:*connect* \
workload
will take perf.data.YYYYMMDDHHMMSS snapshots up to around the
connect syscalls.
- Add --num-synthesize-threads option to control degree of parallelism of the
synthesize_mmap() code which is scanning /proc/PID/task/PID/maps and can be
time consuming. This mimics pre-existing behaviour in 'perf top'.
perf bench:
- Add a multi-threaded synthesize benchmark.
- Add kallsyms parsing benchmark.
Intel PT support:
- Stitch LBR records from multiple samples to get deeper backtraces,
there are caveats, see the csets for details.
- Allow using Intel PT to synthesize callchains for regular events.
- Add support for synthesizing branch stacks for regular events (cycles,
instructions, etc) from Intel PT data.
Misc changes:
- Updated perf vendor events for power9 and Coresight.
- Add flamegraph.py script via 'perf flamegraph'
- Misc other changes, fixes and cleanups - see the Git log for details.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=i27M
-----END PGP SIGNATURE-----
Merge tag 'perf-core-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- Add AMD Fam17h RAPL support
- Introduce CAP_PERFMON to kernel and user space
- Add Zhaoxin CPU support
- Misc fixes and cleanups
Tooling changes:
- perf record:
Introduce '--switch-output-event' to use arbitrary events to be
setup and read from a side band thread and, when they take place a
signal be sent to the main 'perf record' thread, reusing the core
for '--switch-output' to take perf.data snapshots from the ring
buffer used for '--overwrite', e.g.:
# perf record --overwrite -e sched:* \
--switch-output-event syscalls:*connect* \
workload
will take perf.data.YYYYMMDDHHMMSS snapshots up to around the
connect syscalls.
Add '--num-synthesize-threads' option to control degree of
parallelism of the synthesize_mmap() code which is scanning
/proc/PID/task/PID/maps and can be time consuming. This mimics
pre-existing behaviour in 'perf top'.
- perf bench:
Add a multi-threaded synthesize benchmark and kallsyms parsing
benchmark.
- Intel PT support:
Stitch LBR records from multiple samples to get deeper backtraces,
there are caveats, see the csets for details.
Allow using Intel PT to synthesize callchains for regular events.
Add support for synthesizing branch stacks for regular events
(cycles, instructions, etc) from Intel PT data.
Misc changes:
- Updated perf vendor events for power9 and Coresight.
- Add flamegraph.py script via 'perf flamegraph'
- Misc other changes, fixes and cleanups - see the Git log for details
Also, since over the last couple of years perf tooling has matured and
decoupled from the kernel perf changes to a large degree, going
forward Arnaldo is going to send perf tooling changes via direct pull
requests"
* tag 'perf-core-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (163 commits)
perf/x86/rapl: Add AMD Fam17h RAPL support
perf/x86/rapl: Make perf_probe_msr() more robust and flexible
perf/x86/rapl: Flip logic on default events visibility
perf/x86/rapl: Refactor to share the RAPL code between Intel and AMD CPUs
perf/x86/rapl: Move RAPL support to common x86 code
perf/core: Replace zero-length array with flexible-array
perf/x86: Replace zero-length array with flexible-array
perf/x86/intel: Add more available bits for OFFCORE_RESPONSE of Intel Tremont
perf/x86/rapl: Add Ice Lake RAPL support
perf flamegraph: Use /bin/bash for report and record scripts
perf cs-etm: Move definition of 'traceid_list' global variable from header file
libsymbols kallsyms: Move hex2u64 out of header
libsymbols kallsyms: Parse using io api
perf bench: Add kallsyms parsing
perf: cs-etm: Update to build with latest opencsd version.
perf symbol: Fix kernel symbol address display
perf inject: Rename perf_evsel__*() operating on 'struct evsel *' to evsel__*()
perf annotate: Rename perf_evsel__*() operating on 'struct evsel *' to evsel__*()
perf trace: Rename perf_evsel__*() operating on 'struct evsel *' to evsel__*()
perf script: Rename perf_evsel__*() operating on 'struct evsel *' to evsel__*()
...
- RCU-tasks update, including addition of RCU Tasks Trace for
BPF use and TASKS_RUDE_RCU
- kfree_rcu() updates.
- Remove scheduler locking restriction
- RCU CPU stall warning updates.
- Torture-test updates.
- Miscellaneous fixes and other updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=Yisx
-----END PGP SIGNATURE-----
Merge tag 'core-rcu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
"The RCU updates for this cycle were:
- RCU-tasks update, including addition of RCU Tasks Trace for BPF use
and TASKS_RUDE_RCU
- kfree_rcu() updates.
- Remove scheduler locking restriction
- RCU CPU stall warning updates.
- Torture-test updates.
- Miscellaneous fixes and other updates"
* tag 'core-rcu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits)
rcu: Allow for smp_call_function() running callbacks from idle
rcu: Provide rcu_irq_exit_check_preempt()
rcu: Abstract out rcu_irq_enter_check_tick() from rcu_nmi_enter()
rcu: Provide __rcu_is_watching()
rcu: Provide rcu_irq_exit_preempt()
rcu: Make RCU IRQ enter/exit functions rely on in_nmi()
rcu/tree: Mark the idle relevant functions noinstr
x86: Replace ist_enter() with nmi_enter()
x86/mce: Send #MC singal from task work
x86/entry: Get rid of ist_begin/end_non_atomic()
sched,rcu,tracing: Avoid tracing before in_nmi() is correct
sh/ftrace: Move arch_ftrace_nmi_{enter,exit} into nmi exception
lockdep: Always inline lockdep_{off,on}()
hardirq/nmi: Allow nested nmi_enter()
arm64: Prepare arch_nmi_enter() for recursion
printk: Disallow instrumenting print_nmi_enter()
printk: Prepare for nested printk_nmi_enter()
rcutorture: Convert ULONG_CMP_LT() to time_before()
torture: Add a --kasan argument
torture: Save a few lines by using config_override_param initially
...
When "traceoff_on_warning" is enabled and a warning happens, there can still
be many trace events happening on other CPUs between the time the warning
occurred and the last trace event on that same CPU. This can cause confusion
in examining the trace, as it may not be obvious where the warning happened.
By adding a trace print into the trace just before disabling tracing, it
makes it obvious where the warning occurred, and the developer doesn't have
to look at other means to see what CPU it occurred on.
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
With the addition of the in-kernel synthetic event API, synthetic
events are no longer specifically tied to the histogram triggers.
The synthetic event code is also making trace_event_hist.c very
bloated, so for those reasons, move it to a separate file,
trace_events_synth.c, along with a new trace_synth.h header file.
Because synthetic events are now independent from hist triggers, add a
new CONFIG_SYNTH_EVENTS config option, and have CONFIG_HIST_TRIGGERS
select it, and have CONFIG_SYNTH_EVENT_GEN_TEST depend on it.
Link: http://lkml.kernel.org/r/4d1fa1f85ed5982706ac44844ac92451dcb04715.1590693308.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a new "hist_debug" file for each trace event, which when read will
dump out a bunch of internal details about the hist triggers defined
on that event.
This is normally off but can be enabled by saying 'y' to the new
CONFIG_HIST_TRIGGERS_DEBUG config option.
This is in support of the new Documentation file describing histogram
internals, Documentation/trace/histogram-design.rst, which was
requested by developers trying to understand the internals when
extending or making use of the hist triggers for higher-level tools.
The histogram-design.rst documentation refers to the hist_debug files
and demonstrates their use with output in the test examples.
Link: http://lkml.kernel.org/r/77914c22b0ba493d9783c53bbfbc6087d6a7e1b1.1585941485.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since trace_state.disabled is set in __synth_event_trace_start() at
the same time -ENOENT is returned, don't bother returning -ENOENT -
just have callers check trace_state.disabled instead, and avoid the
extra return val munging.
Link: http://lkml.kernel.org/r/87315c3889af870e8370e82b76cf48b426d70130.1585941485.git.zanussi@kernel.org
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@godmis.org>
tracing_pipe_buf_ops has identical ops to default_pipe_buf_ops, so use
that instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Elsewhere in the file, the function trace_kprobe_has_same_kprobe uses
a trace_probe_event.probes object as the second argument of
list_for_each_entry, ie as a list head, while the list_for_each_entry
iterates over the list fields of the trace_probe structures, making
them the list elements. So, exchange the arguments on the list_add
call to put the list head in the second argument.
Since both list_head structures were just initialized, this problem
did not cause any loss of information.
Link: https://lkml.kernel.org/r/1588879808-24488-1-git-send-email-Julia.Lawall@inria.fr
Fixes: 60d53e2c3b ("tracing/probe: Split trace_event related data from trace_probe")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When an anomaly is detected in the function call modification
code, ftrace_bug() is called to disable function tracing as well
as give some warn and information that may help debug the problem.
But currently, we call FTRACE_WARN_ON_ONCE() first in ftrace_bug(),
so when panic_on_warn is set, we can't see the debugging information
here. Call FTRACE_WARN_ON_ONCE() at the end of ftrace_bug() to ensure
that the debugging information is displayed first.
after this patch, the dmesg looks like:
------------[ ftrace bug ]------------
ftrace failed to modify
[<ffff800010081004>] bcm2835_handle_irq+0x4/0x58
actual: 1f:20:03:d5
Setting ftrace call site to call ftrace function
ftrace record flags: 80000001
(1)
expected tramp: ffff80001009d6f0
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1635 at kernel/trace/ftrace.c:2078 ftrace_bug+0x204/0x238
Kernel panic - not syncing: panic_on_warn set ...
CPU: 2 PID: 1635 Comm: sh Not tainted 5.7.0-rc5-00033-gb922183867f5 #14
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x1b0
show_stack+0x20/0x30
dump_stack+0xc0/0x10c
panic+0x16c/0x368
__warn+0x120/0x160
report_bug+0xc8/0x160
bug_handler+0x28/0x98
brk_handler+0x70/0xd0
do_debug_exception+0xcc/0x1ac
el1_sync_handler+0xe4/0x120
el1_sync+0x7c/0x100
ftrace_bug+0x204/0x238
Link: https://lkml.kernel.org/r/20200515100828.7091-1-cj.chengjian@huawei.com
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
SuperH is the last remaining user of arch_ftrace_nmi_{enter,exit}(),
remove it from the generic code and into the SuperH code.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20200505134101.248881738@linutronix.de
Force inlining and prevent instrumentation of all sorts by marking the
functions which are invoked from low level entry code with 'noinstr'.
Split the irqflags tracking into two parts. One which does the heavy
lifting while RCU is watching and the final one which can be invoked after
RCU is turned off.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/20200505134100.484532537@linutronix.de
trace_hardirqs_on/off() is only partially safe vs. RCU idle. The tracer
core itself is safe, but the resulting tracepoints can be utilized by
e.g. BPF which is unsafe.
Provide variants which do not contain the lockdep invocation so the lockdep
and tracer invocations can be split at the call site and placed
properly. This is required because lockdep needs to be aware of the state
before switching away from RCU idle and after switching to RCU idle because
these transitions can take locks.
As these code pathes are going to be non-instrumentable the tracer can be
invoked after RCU is turned on and before the switch to RCU idle. So for
these new variants there is no need to invoke the rcuidle aware tracer
functions.
Name them so they match the lockdep counterparts.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200505134100.270771162@linutronix.de
Currently informational messages within block trace do not have PID
information of the process reporting the message included. With BFQ it
is sometimes useful to have the information and there's no good reason
to omit the information from the trace. So just fill in pid information
when generating note message.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the bpf verifier trace check into the new switch statement in
HEAD.
Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) Fix sk_psock reference count leak on receive, from Xiyu Yang.
2) CONFIG_HNS should be invisible, from Geert Uytterhoeven.
3) Don't allow locking route MTUs in ipv6, RFCs actually forbid this,
from Maciej Żenczykowski.
4) ipv4 route redirect backoff wasn't actually enforced, from Paolo
Abeni.
5) Fix netprio cgroup v2 leak, from Zefan Li.
6) Fix infinite loop on rmmod in conntrack, from Florian Westphal.
7) Fix tcp SO_RCVLOWAT hangs, from Eric Dumazet.
8) Various bpf probe handling fixes, from Daniel Borkmann.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (68 commits)
selftests: mptcp: pm: rm the right tmp file
dpaa2-eth: properly handle buffer size restrictions
bpf: Restrict bpf_trace_printk()'s %s usage and add %pks, %pus specifier
bpf: Add bpf_probe_read_{user, kernel}_str() to do_refine_retval_range
bpf: Restrict bpf_probe_read{, str}() only to archs where they work
MAINTAINERS: Mark networking drivers as Maintained.
ipmr: Add lockdep expression to ipmr_for_each_table macro
ipmr: Fix RCU list debugging warning
drivers: net: hamradio: Fix suspicious RCU usage warning in bpqether.c
net: phy: broadcom: fix BCM54XX_SHD_SCR3_TRDDAPD value for BCM54810
tcp: fix error recovery in tcp_zerocopy_receive()
MAINTAINERS: Add Jakub to networking drivers.
MAINTAINERS: another add of Karsten Graul for S390 networking
drivers: ipa: fix typos for ipa_smp2p structure doc
pppoe: only process PADT targeted at local interfaces
selftests/bpf: Enforce returning 0 for fentry/fexit programs
bpf: Enforce returning 0 for fentry/fexit progs
net: stmmac: fix num_por initialization
security: Fix the default value of secid_to_secctx hook
libbpf: Fix register naming in PT_REGS s390 macros
...
Implement permissions as stated in uapi/linux/capability.h
In order to do that the verifier allow_ptr_leaks flag is split
into four flags and they are set as:
env->allow_ptr_leaks = bpf_allow_ptr_leaks();
env->bypass_spec_v1 = bpf_bypass_spec_v1();
env->bypass_spec_v4 = bpf_bypass_spec_v4();
env->bpf_capable = bpf_capable();
The first three currently equivalent to perfmon_capable(), since leaking kernel
pointers and reading kernel memory via side channel attacks is roughly
equivalent to reading kernel memory with cap_perfmon.
'bpf_capable' enables bounded loops, precision tracking, bpf to bpf calls and
other verifier features. 'allow_ptr_leaks' enable ptr leaks, ptr conversions,
subtraction of pointers. 'bypass_spec_v1' disables speculative analysis in the
verifier, run time mitigations in bpf array, and enables indirect variable
access in bpf programs. 'bypass_spec_v4' disables emission of sanitation code
by the verifier.
That means that the networking BPF program loaded with CAP_BPF + CAP_NET_ADMIN
will have speculative checks done by the verifier and other spectre mitigation
applied. Such networking BPF program will not be able to leak kernel pointers
and will not be able to access arbitrary kernel memory.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200513230355.7858-3-alexei.starovoitov@gmail.com
Usage of plain %s conversion specifier in bpf_trace_printk() suffers from the
very same issue as bpf_probe_read{,str}() helpers, that is, it is broken on
archs with overlapping address ranges.
While the helpers have been addressed through work in 6ae08ae3de ("bpf: Add
probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers"), we need
an option for bpf_trace_printk() as well to fix it.
Similarly as with the helpers, force users to make an explicit choice by adding
%pks and %pus specifier to bpf_trace_printk() which will then pick the corresponding
strncpy_from_unsafe*() variant to perform the access under KERNEL_DS or USER_DS.
The %pk* (kernel specifier) and %pu* (user specifier) can later also be extended
for other objects aside strings that are probed and printed under tracing, and
reused out of other facilities like bpf_seq_printf() or BTF based type printing.
Existing behavior of %s for current users is still kept working for archs where it
is not broken and therefore gated through CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE.
For archs not having this property we fall-back to pick probing under KERNEL_DS as
a sensible default.
Fixes: 8d3b7dce86 ("bpf: add support for %s specifier to bpf_trace_printk()")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Link: https://lore.kernel.org/bpf/20200515101118.6508-4-daniel@iogearbox.net
Given the legacy bpf_probe_read{,str}() BPF helpers are broken on archs
with overlapping address ranges, we should really take the next step to
disable them from BPF use there.
To generally fix the situation, we've recently added new helper variants
bpf_probe_read_{user,kernel}() and bpf_probe_read_{user,kernel}_str().
For details on them, see 6ae08ae3de ("bpf: Add probe_read_{user, kernel}
and probe_read_{user,kernel}_str helpers").
Given bpf_probe_read{,str}() have been around for ~5 years by now, there
are plenty of users at least on x86 still relying on them today, so we
cannot remove them entirely w/o breaking the BPF tracing ecosystem.
However, their use should be restricted to archs with non-overlapping
address ranges where they are working in their current form. Therefore,
move this behind a CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE and
have x86, arm64, arm select it (other archs supporting it can follow-up
on it as well).
For the remaining archs, they can workaround easily by relying on the
feature probe from bpftool which spills out defines that can be used out
of BPF C code to implement the drop-in replacement for old/new kernels
via: bpftool feature probe macro
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/bpf/20200515101118.6508-2-daniel@iogearbox.net
- Fix a crash when having function tracing and function stack tracing on
the command line. The ftrace trampolines are created as executable and
read only. But the stack tracer tries to modify them with text_poke()
which expects all kernel text to still be writable at boot.
Keep the trampolines writable at boot, and convert them to read-only
with the rest of the kernel.
- A selftest was triggering in the ring buffer iterator code, that
is no longer valid with the update of keeping the ring buffer
writable while a iterator is reading. Just bail after three failed
attempts to get an event and remove the warning and disabling of the
ring buffer.
- While modifying the ring buffer code, decided to remove all the
unnecessary BUG() calls.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXr1CDhQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qsXcAQCoL229SBrtHsn4DUO7eAQRppUT3hNw
RuKzvQ56+1GccQEAh8VGCeg89uMSK6imrTujEl6VmOUdbgrD5R96yiKoGQw=
=vi+k
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull more tracing fixes from Steven Rostedt:
"Various tracing fixes:
- Fix a crash when having function tracing and function stack tracing
on the command line.
The ftrace trampolines are created as executable and read only. But
the stack tracer tries to modify them with text_poke() which
expects all kernel text to still be writable at boot. Keep the
trampolines writable at boot, and convert them to read-only with
the rest of the kernel.
- A selftest was triggering in the ring buffer iterator code, that is
no longer valid with the update of keeping the ring buffer writable
while a iterator is reading.
Just bail after three failed attempts to get an event and remove
the warning and disabling of the ring buffer.
- While modifying the ring buffer code, decided to remove all the
unnecessary BUG() calls"
* tag 'trace-v5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ring-buffer: Remove all BUG() calls
ring-buffer: Don't deactivate the ring buffer on failed iterator reads
x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up
There's a lot of checks to make sure the ring buffer is working, and if an
anomaly is detected, it safely shuts itself down. But there's a few cases
that it will call BUG(), which defeats the point of being safe (it crashes
the kernel when an anomaly is found!). There's no reason for them. Switch
them all to either WARN_ON_ONCE() (when no ring buffer descriptor is present),
or to RB_WARN_ON() (when a ring buffer descriptor is present).
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If the function tracer is running and the trace file is read (which uses the
ring buffer iterator), the iterator can get in sync with the writes, and
caues it to fail to find a page with content it can read three times. This
causes a warning and deactivation of the ring buffer code.
Looking at the other cases of failure to get an event, it appears that
there's a chance that the writer could cause them too. Since the iterator is
a "best effort" to read the ring buffer if there's an active writer (the
consumer reader is made for this case "see trace_pipe"), if it fails to get
an event after three tries, simply give up and return NULL. Don't warn, nor
disable the ring buffer on this failure.
Link: https://lore.kernel.org/r/20200429090508.GG5770@shao2-debian
Reported-by: kernel test robot <lkp@intel.com>
Fixes: ff84c50cfb ("ring-buffer: Do not die if rb_iter_peek() fails more than thrice")
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Booting one of my machines, it triggered the following crash:
Kernel/User page tables isolation: enabled
ftrace: allocating 36577 entries in 143 pages
Starting tracer 'function'
BUG: unable to handle page fault for address: ffffffffa000005c
#PF: supervisor write access in kernel mode
#PF: error_code(0x0003) - permissions violation
PGD 2014067 P4D 2014067 PUD 2015063 PMD 7b253067 PTE 7b252061
Oops: 0003 [#1] PREEMPT SMP PTI
CPU: 0 PID: 0 Comm: swapper Not tainted 5.4.0-test+ #24
Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007
RIP: 0010:text_poke_early+0x4a/0x58
Code: 34 24 48 89 54 24 08 e8 bf 72 0b 00 48 8b 34 24 48 8b 4c 24 08 84 c0 74 0b 48 89 df f3 a4 48 83 c4 10 5b c3 9c 58 fa 48 89 df <f3> a4 50 9d 48 83 c4 10 5b e9 d6 f9 ff ff
0 41 57 49
RSP: 0000:ffffffff82003d38 EFLAGS: 00010046
RAX: 0000000000000046 RBX: ffffffffa000005c RCX: 0000000000000005
RDX: 0000000000000005 RSI: ffffffff825b9a90 RDI: ffffffffa000005c
RBP: ffffffffa000005c R08: 0000000000000000 R09: ffffffff8206e6e0
R10: ffff88807b01f4c0 R11: ffffffff8176c106 R12: ffffffff8206e6e0
R13: ffffffff824f2440 R14: 0000000000000000 R15: ffffffff8206eac0
FS: 0000000000000000(0000) GS:ffff88807d400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffa000005c CR3: 0000000002012000 CR4: 00000000000006b0
Call Trace:
text_poke_bp+0x27/0x64
? mutex_lock+0x36/0x5d
arch_ftrace_update_trampoline+0x287/0x2d5
? ftrace_replace_code+0x14b/0x160
? ftrace_update_ftrace_func+0x65/0x6c
__register_ftrace_function+0x6d/0x81
ftrace_startup+0x23/0xc1
register_ftrace_function+0x20/0x37
func_set_flag+0x59/0x77
__set_tracer_option.isra.19+0x20/0x3e
trace_set_options+0xd6/0x13e
apply_trace_boot_options+0x44/0x6d
register_tracer+0x19e/0x1ac
early_trace_init+0x21b/0x2c9
start_kernel+0x241/0x518
? load_ucode_intel_bsp+0x21/0x52
secondary_startup_64+0xa4/0xb0
I was able to trigger it on other machines, when I added to the kernel
command line of both "ftrace=function" and "trace_options=func_stack_trace".
The cause is the "ftrace=function" would register the function tracer
and create a trampoline, and it will set it as executable and
read-only. Then the "trace_options=func_stack_trace" would then update
the same trampoline to include the stack tracer version of the function
tracer. But since the trampoline already exists, it updates it with
text_poke_bp(). The problem is that text_poke_bp() called while
system_state == SYSTEM_BOOTING, it will simply do a memcpy() and not
the page mapping, as it would think that the text is still read-write.
But in this case it is not, and we take a fault and crash.
Instead, lets keep the ftrace trampolines read-write during boot up,
and then when the kernel executable text is set to read-only, the
ftrace trampolines get set to read-only as well.
Link: https://lkml.kernel.org/r/20200430202147.4dc6e2de@oasis.local.home
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: stable@vger.kernel.org
Fixes: 768ae4406a ("x86/ftrace: Use text_poke()")
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Unfortunately, the last set of fixes introduced some minor bugs:
- The bootconfig apply_xbc() leak fix caused the application to return
a positive number on success, when it should have returned zero.
- The preempt_irq_delay_thread fix to make the creation code
wait for the kthread to finish to prevent it from executing after
module unload, can now cause the kthread to exit before it even
executes (preventing it to run its tests).
- The fix to the bootconfig that fixed the initrd to remove the
bootconfig from causing the kernel to panic, now prints a warning
that the bootconfig is not found, even when bootconfig is not
on the command line.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXrq2ehQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qrdjAQDGNaJa7Ft13KTDTNTioKmOorOi38vF
ava4E3uBHl3StQD/anJmVq7Kk4WJFKGYemV6usbjDqy510PCFu/VQ1AbGQc=
=hJvk
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Fixes to previous fixes.
Unfortunately, the last set of fixes introduced some minor bugs:
- The bootconfig apply_xbc() leak fix caused the application to
return a positive number on success, when it should have returned
zero.
- The preempt_irq_delay_thread fix to make the creation code wait for
the kthread to finish to prevent it from executing after module
unload, can now cause the kthread to exit before it even executes
(preventing it to run its tests).
- The fix to the bootconfig that fixed the initrd to remove the
bootconfig from causing the kernel to panic, now prints a warning
that the bootconfig is not found, even when bootconfig is not on
the command line"
* tag 'trace-v5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
bootconfig: Fix to prevent warning message if no bootconfig option
tracing: Wait for preempt irq delay thread to execute
tools/bootconfig: Fix apply_xbc() to return zero on success
A bug report was posted that running the preempt irq delay module on a slow
machine, and removing it quickly could lead to the thread created by the
modlue to execute after the module is removed, and this could cause the
kernel to crash. The fix for this was to call kthread_stop() after creating
the thread to make sure it finishes before allowing the module to be
removed.
Now this caused the opposite problem on fast machines. What now happens is
the kthread_stop() can cause the kthread never to execute and the test never
to run. To fix this, add a completion and wait for the kthread to execute,
then wait for it to end.
This issue caused the ftracetest selftests to fail on the preemptirq tests.
Link: https://lore.kernel.org/r/20200510114210.15d9e4af@oasis.local.home
Cc: stable@vger.kernel.org
Fixes: d16a8c3107 ("tracing: Wait for preempt irq delay thread to finish")
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Two helpers bpf_seq_printf and bpf_seq_write, are added for
writing data to the seq_file buffer.
bpf_seq_printf supports common format string flag/width/type
fields so at least I can get identical results for
netlink and ipv6_route targets.
For bpf_seq_printf and bpf_seq_write, return value -EOVERFLOW
specifically indicates a write failure due to overflow, which
means the object will be repeated in the next bpf invocation
if object collection stays the same. Note that if the object
collection is changed, depending how collection traversal is
done, even if the object still in the collection, it may not
be visited.
For bpf_seq_printf, format %s, %p{i,I}{4,6} needs to
read kernel memory. Reading kernel memory may fail in
the following two cases:
- invalid kernel address, or
- valid kernel address but requiring a major fault
If reading kernel memory failed, the %s string will be
an empty string and %p{i,I}{4,6} will be all 0.
Not returning error to bpf program is consistent with
what bpf_trace_printk() does for now.
bpf_seq_printf may return -EBUSY meaning that internal percpu
buffer for memory copy of strings or other pointees is
not available. Bpf program can return 1 to indicate it
wants the same object to be repeated. Right now, this should not
happen on no-RT kernels since migrate_disable(), which guards
bpf prog call, calls preempt_disable().
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175914.2476661-1-yhs@fb.com
We have some rather random rules about when we accept the
"maybe-initialized" warnings, and when we don't.
For example, we consider it unreliable for gcc versions < 4.9, but also
if -O3 is enabled, or if optimizing for size. And then various kernel
config options disabled it, because they know that they trigger that
warning by confusing gcc sufficiently (ie PROFILE_ALL_BRANCHES).
And now gcc-10 seems to be introducing a lot of those warnings too, so
it falls under the same heading as 4.9 did.
At the same time, we have a very straightforward way to _enable_ that
warning when wanted: use "W=2" to enable more warnings.
So stop playing these ad-hoc games, and just disable that warning by
default, with the known and straight-forward "if you want to work on the
extra compiler warnings, use W=123".
Would it be great to have code that is always so obvious that it never
confuses the compiler whether a variable is used initialized or not?
Yes, it would. In a perfect world, the compilers would be smarter, and
our source code would be simpler.
That's currently not the world we live in, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following sparse warning:
kernel/trace/trace.c:950:6: warning: symbol 'tracing_snapshot_instance_cond'
was not declared. Should it be static?
Link: http://lkml.kernel.org/r/1587614905-48692-1-git-send-email-zou_wei@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
x86_64 lazily maps in the vmalloc pages, and the way this works with per_cpu
areas can be complex, to say the least. Mappings may happen at boot up, and
if nothing synchronizes the page tables, those page mappings may not be
synced till they are used. This causes issues for anything that might touch
one of those mappings in the path of the page fault handler. When one of
those unmapped mappings is touched in the page fault handler, it will cause
another page fault, which in turn will cause a page fault, and leave us in
a loop of page faults.
Commit 763802b53a ("x86/mm: split vmalloc_sync_all()") split
vmalloc_sync_all() into vmalloc_sync_unmappings() and
vmalloc_sync_mappings(), as on system exit, it did not need to do a full
sync on x86_64 (although it still needed to be done on x86_32). By chance,
the vmalloc_sync_all() would synchronize the page mappings done at boot up
and prevent the per cpu area from being a problem for tracing in the page
fault handler. But when that synchronization in the exit of a task became a
nop, it caused the problem to appear.
Link: https://lore.kernel.org/r/20200429054857.66e8e333@oasis.local.home
Cc: stable@vger.kernel.org
Fixes: 737223fbca ("tracing: Consolidate buffer allocation code")
Reported-by: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Suggested-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Running on a slower machine, it is possible that the preempt delay kernel
thread may still be executing if the module was immediately removed after
added, and this can cause the kernel to crash as the kernel thread might be
executing after its code has been removed.
There's no reason that the caller of the code shouldn't just wait for the
delay thread to finish, as the thread can also be created by a trigger in
the sysfs code, which also has the same issues.
Link: http://lore.kernel.org/r/5EA2B0C8.2080706@cn.fujitsu.com
Cc: stable@vger.kernel.org
Fixes: 793937236d ("lib: Add module for testing preemptoff/irqsoff latency tracers")
Reported-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reject the new event which has NULL location for kprobes.
For kprobes, user must specify at least the location.
Link: http://lkml.kernel.org/r/158779376597.6082.1411212055469099461.stgit@devnote2
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 2a588dd1d5 ("tracing: Add kprobe event command generation functions")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fix boottime kprobe events to use API correctly for
multiple events.
For example, when we set a multiprobe kprobe events in
bootconfig like below,
ftrace.event.kprobes.myevent {
probes = "vfs_read $arg1 $arg2", "vfs_write $arg1 $arg2"
}
This cause an error;
trace_boot: Failed to add probe: p:kprobes/myevent (null) vfs_read $arg1 $arg2 vfs_write $arg1 $arg2
This shows the 1st argument becomes NULL and multiprobes
are merged to 1 probe.
Link: http://lkml.kernel.org/r/158779375766.6082.201939936008972838.stgit@devnote2
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 29a1548105 ("tracing: Change trace_boot to use kprobe_event interface")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fix a typo that resulted in an unnecessary double
initialization to addr.
Link: http://lkml.kernel.org/r/158779374968.6082.2337484008464939919.stgit@devnote2
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Fixes: c7411a1a12 ("tracing/kprobe: Check whether the non-suffixed symbol is notrace")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull in Christoph Hellwig's series that changes the sysctl's ->proc_handler
methods to take kernel pointers instead. It gets rid of the set_fs address
space overrides used by BPF. As per discussion, pull in the feature branch
into bpf-next as it relates to BPF sysctl progs.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200427071508.GV23230@ZenIV.linux.org.uk/T/
This commit replaces the schedule_on_each_cpu(ftrace_sync) instances
with synchronize_rcu_tasks_rude().
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
[ paulmck: Make Kconfig adjustments noted by kbuild test robot. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.
As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
On a device like a cellphone which is constantly suspending
and resuming CLOCK_MONOTONIC is not particularly useful for
keeping track of or reacting to external network events.
Instead you want to use CLOCK_BOOTTIME.
Hence add bpf_ktime_get_boot_ns() as a mirror of bpf_ktime_get_ns()
based around CLOCK_BOOTTIME instead of CLOCK_MONOTONIC.
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Fix the following sparse warning:
kernel/trace/tracing_map.c:286:6: warning: symbol
'tracing_map_array_clear' was not declared. Should it be static?
kernel/trace/tracing_map.c:297:6: warning: symbol
'tracing_map_array_free' was not declared. Should it be static?
kernel/trace/tracing_map.c:319:26: warning: symbol
'tracing_map_array_alloc' was not declared. Should it be static?
Link: http://lkml.kernel.org/r/20200410073312.38855-1-yanaijie@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
kernel + tools/perf:
Alexey Budankov:
- Introduce CAP_PERFMON to kernel and user space.
callchains:
Adrian Hunter:
- Allow using Intel PT to synthesize callchains for regular events.
Kan Liang:
- Stitch LBR records from multiple samples to get deeper backtraces,
there are caveats, see the csets for details.
perf script:
Andreas Gerstmayr:
- Add flamegraph.py script
BPF:
Jiri Olsa:
- Synthesize bpf_trampoline/dispatcher ksymbol events.
perf stat:
Arnaldo Carvalho de Melo:
- Honour --timeout for forked workloads.
Stephane Eranian:
- Force error in fallback on :k events, to avoid counting nothing when
the user asks for kernel events but is not allowed to.
perf bench:
Ian Rogers:
- Add event synthesis benchmark.
tools api fs:
Stephane Eranian:
- Make xxx__mountpoint() more scalable
libtraceevent:
He Zhe:
- Handle return value of asprintf.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQR2GiIUctdOfX2qHhGyPKLppCJ+JwUCXp2LlQAKCRCyPKLppCJ+
J95oAP0ZihVUhESv/gdeX0IDE5g6Rd2V6LNcRj+jb7gX9NlQkwD/UfS454WV1ftQ
qTwrkKPzY/5Tm2cLuVE7r7fJ6naDHgU=
=FHm4
-----END PGP SIGNATURE-----
Merge tag 'perf-core-for-mingo-5.8-20200420' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core fixes and improvements from Arnaldo Carvalho de Melo:
kernel + tools/perf:
Alexey Budankov:
- Introduce CAP_PERFMON to kernel and user space.
callchains:
Adrian Hunter:
- Allow using Intel PT to synthesize callchains for regular events.
Kan Liang:
- Stitch LBR records from multiple samples to get deeper backtraces,
there are caveats, see the csets for details.
perf script:
Andreas Gerstmayr:
- Add flamegraph.py script
BPF:
Jiri Olsa:
- Synthesize bpf_trampoline/dispatcher ksymbol events.
perf stat:
Arnaldo Carvalho de Melo:
- Honour --timeout for forked workloads.
Stephane Eranian:
- Force error in fallback on :k events, to avoid counting nothing when
the user asks for kernel events but is not allowed to.
perf bench:
Ian Rogers:
- Add event synthesis benchmark.
tools api fs:
Stephane Eranian:
- Make xxx__mountpoint() more scalable
libtraceevent:
He Zhe:
- Handle return value of asprintf.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Open access to bpf_trace monitoring for CAP_PERFMON privileged process.
Providing the access under CAP_PERFMON capability singly, without the
rest of CAP_SYS_ADMIN credentials, excludes chances to misuse the
credentials and makes operation more secure.
CAP_PERFMON implements the principle of least privilege for performance
monitoring and observability operations (POSIX IEEE 1003.1e 2.2.2.39
principle of least privilege: A security design principle that states
that a process or program be granted only those privileges (e.g.,
capabilities) necessary to accomplish its legitimate function, and only
for the time that such privileges are actually required)
For backward compatibility reasons access to bpf_trace monitoring
remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN
usage for secure bpf_trace monitoring is discouraged with respect to
CAP_PERFMON capability.
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/c0a0ae47-8b6e-ff3e-416b-3cd1faaf71c0@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-----BEGIN PGP SIGNATURE-----
iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAl6TbaUeHHRvcnZhbGRz
QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGhgkH/iWpiKvosA20HJjC
rBqYeJPxQsgZTuBieWJ+MeVxbpcF7RlM4c+glyvg3QJhHwIEG58dl6LBrQbAyBAR
aFHNojr1iAYOruVCGnU3pA008YZiwUIDv/ZQ4DF8fmIU2vI2mJ6qHBv3XDl4G2uR
Nwz8Eu9AgIwZM5coomVOSmoWyFy7Vxmb7W+3t5VmKsvOWx4ib9kyQtOIkvQDEl7j
XCbWfI0xDQr6LFOm4jnCi5R/LhJ2LIqqIvHHrunbpszM8IwK797jCXz4im+dmd5Y
+km46N7a8pDqri36xXz1gdBAU3eG7Pt1NyvfjwRVTdX4GquQ2MT0GoojxbLxUP3y
3pEsQuE=
=whbL
-----END PGP SIGNATURE-----
Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refresh
Resolve these conflicts:
arch/x86/Kconfig
arch/x86/kernel/Makefile
Do a minor "evil merge" to move the KCSAN entry up a bit by a few lines
in the Kconfig to reduce the probability of future conflicts.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- The ring buffer is no longer disabled when reading the trace file.
The trace_pipe file was made to be used for live tracing and reading
as it acted like the normal producer/consumer. As the trace file
would not consume the data, the easy way of handling it was to just
disable writes to the ring buffer. This came to a surprise to the
BPF folks who complained about lost events due to reading.
This is no longer an issue. If someone wants to keep the old disabling
there's a new option "pause-on-trace" that can be set.
- New set_ftrace_notrace_pid file. PIDs in this file will not be traced
by the function tracer. Similar to set_ftrace_pid, which makes the
function tracer only trace those tasks with PIDs in the file, the
set_ftrace_notrace_pid does the reverse.
- New set_event_notrace_pid file. PIDs in this file will cause events
not to be traced if triggered by a task with a matching PID.
Similar to the set_event_pid file but will not be traced.
Note, sched_waking and sched_switch events may still be trace if
one of the tasks referenced by those events contains a PID that
is allowed to be traced.
Tracing related features:
- New bootconfig option, that is attached to the initrd file.
If bootconfig is on the command line, then the initrd file
is searched looking for a bootconfig appended at the end.
- New GPU tracepoint infrastructure to help the gfx drivers to get
off debugfs (acked by Greg Kroah-Hartman)
Other minor updates and fixes.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXokgWRQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qgrHAP0UkKs/52JY4oWa3OIh/OqK+vnCrIwz
zGvDFOYM0fKbwgD9FZWgzlcaYK5m2Cxlhp4VoraZveHMLJUhnEHtdX6X0wk=
=Rebj
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"New tracing features:
- The ring buffer is no longer disabled when reading the trace file.
The trace_pipe file was made to be used for live tracing and
reading as it acted like the normal producer/consumer. As the trace
file would not consume the data, the easy way of handling it was to
just disable writes to the ring buffer.
This came to a surprise to the BPF folks who complained about lost
events due to reading. This is no longer an issue. If someone wants
to keep the old disabling there's a new option "pause-on-trace"
that can be set.
- New set_ftrace_notrace_pid file. PIDs in this file will not be
traced by the function tracer.
Similar to set_ftrace_pid, which makes the function tracer only
trace those tasks with PIDs in the file, the set_ftrace_notrace_pid
does the reverse.
- New set_event_notrace_pid file. PIDs in this file will cause events
not to be traced if triggered by a task with a matching PID.
Similar to the set_event_pid file but will not be traced. Note,
sched_waking and sched_switch events may still be traced if one of
the tasks referenced by those events contains a PID that is allowed
to be traced.
Tracing related features:
- New bootconfig option, that is attached to the initrd file.
If bootconfig is on the command line, then the initrd file is
searched looking for a bootconfig appended at the end.
- New GPU tracepoint infrastructure to help the gfx drivers to get
off debugfs (acked by Greg Kroah-Hartman)
And other minor updates and fixes"
* tag 'trace-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits)
tracing: Do not allocate buffer in trace_find_next_entry() in atomic
tracing: Add documentation on set_ftrace_notrace_pid and set_event_notrace_pid
selftests/ftrace: Add test to test new set_event_notrace_pid file
selftests/ftrace: Add test to test new set_ftrace_notrace_pid file
tracing: Create set_event_notrace_pid to not trace tasks
ftrace: Create set_ftrace_notrace_pid to not trace tasks
ftrace: Make function trace pid filtering a bit more exact
ftrace/kprobe: Show the maxactive number on kprobe_events
tracing: Have the document reflect that the trace file keeps tracing enabled
ring-buffer/tracing: Have iterator acknowledge dropped events
tracing: Do not disable tracing when reading the trace file
ring-buffer: Do not disable recording when there is an iterator
ring-buffer: Make resize disable per cpu buffer instead of total buffer
ring-buffer: Optimize rb_iter_head_event()
ring-buffer: Do not die if rb_iter_peek() fails more than thrice
ring-buffer: Have rb_iter_head_event() handle concurrent writer
ring-buffer: Add page_stamp to iterator for synchronization
ring-buffer: Rename ring_buffer_read() to read_buffer_iter_advance()
ring-buffer: Have ring_buffer_empty() not depend on tracing stopped
tracing: Save off entry when peeking at next entry
...
When dumping out the trace data in latency format, a check is made to peek
at the next event to compare its timestamp to the current one, and if the
delta is of a greater size, it will add a marker showing so. But to do this,
it needs to save the current event otherwise peeking at the next event will
remove the current event. To save the event, a temp buffer is used, and if
the event is bigger than the temp buffer, the temp buffer is freed and a
bigger buffer is allocated.
This allocation is a problem when called in atomic context. The only way
this gets called via atomic context is via ftrace_dump(). Thus, use a static
buffer of 128 bytes (which covers most events), and if the event is bigger
than that, simply return NULL. The callers of trace_find_next_entry() need
to handle a NULL case, as that's what would happen if the allocation failed.
Link: https://lore.kernel.org/r/20200326091256.GR11705@shao2-debian
Fixes: ff895103a8 ("tracing: Save off entry when peeking at next entry")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Introduce types and configs for bpf programs that can be attached to
LSM hooks. The programs can be enabled by the config option
CONFIG_BPF_LSM.
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Florent Revest <revest@google.com>
Reviewed-by: Thomas Garnier <thgarnie@google.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Link: https://lore.kernel.org/bpf/20200329004356.27286-2-kpsingh@chromium.org
There's currently a way to select a task that should only have its events
traced, but there's no way to select a task not to have itsevents traced.
Add a set_event_notrace_pid file that acts the same as set_event_pid (and is
also affected by event-fork), but the task pids in this file will not be
traced even if they are listed in the set_event_pid file. This makes it easy
for tools like trace-cmd to "hide" itself from beint traced by events when
it is recording other tasks.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
There's currently a way to select a task that should only be traced by
functions, but there's no way to select a task not to be traced by the
function tracer. Add a set_ftrace_notrace_pid file that acts the same as
set_ftrace_pid (and is also affected by function-fork), but the task pids in
this file will not be traced even if they are listed in the set_ftrace_pid
file. This makes it easy for tools like trace-cmd to "hide" itself from the
function tracer when it is recording other tasks.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The set_ftrace_pid file is used to filter function tracing to only trace
tasks that are listed in that file. Instead of testing the pids listed in
that file (it's a bitmask) at each function trace event, the logic is done
via a sched_switch hook. A flag is set when the next task to run is in the
list of pids in the set_ftrace_pid file. But the sched_switch hook is not at
the exact location of when the task switches, and the flag gets set before
the task to be traced actually runs. This leaves a residue of traced
functions that do not belong to the pid that should be filtered on.
By changing the logic slightly, where instead of having a boolean flag to
test, record the pid that should be traced, with special values for not to
trace and always trace. Then at each function call, a check will be made to
see if the function should be ignored, or if the current pid matches the
function that should be traced, and only trace if it matches (or if it has
the special value to always trace).
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Have the ring_buffer_iterator set a flag if events were dropped as it were
to go and peek at the next event. Have the trace file display this fact if
it happened with a "LOST EVENTS" message.
Link: http://lkml.kernel.org/r/20200317213417.045858900@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When opening the "trace" file, it is no longer necessary to disable tracing.
Note, a new option is created called "pause-on-trace", when set, will cause
the trace file to emulate its original behavior.
Link: http://lkml.kernel.org/r/20200317213416.903351225@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Now that the iterator can handle a concurrent writer, do not disable writing
to the ring buffer when there is an iterator present.
Link: http://lkml.kernel.org/r/20200317213416.759770696@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When the ring buffer becomes writable for even when the trace file is read,
it must still not be resized. But since tracers can be activated while the
trace file is being read, the irqsoff tracer can modify the per CPU buffers,
and this can cause the reader of the trace file to update the wrong buffer's
resize disable bit, as the irqsoff tracer swaps out cpu buffers.
By making the resize disable per cpu_buffer, it makes the update follow the
per cpu_buffer even if it's swapped out with the snapshot buffer and keeps
the release of the trace file modifying the same data as the open did.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Overlapping header include additions in macsec.c
A bug fix in 'net' overlapping with the removal of 'version'
string in ena_netdev.c
Overlapping test additions in selftests Makefile
Overlapping PCI ID table adjustments in iwlwifi driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
Previously the system would lock up if ftrace was enabled together with
KCSAN. This is due to recursion on reporting if the tracer code is
instrumented with KCSAN.
To avoid this for all types of tracing, disable KCSAN instrumentation
for all of kernel/trace.
Furthermore, since KCSAN relies on udelay() to introduce delay, we have
to disable ftrace for udelay() (currently done for x86) in case KCSAN is
used together with lockdep and ftrace. The reason is that it may corrupt
lockdep IRQ flags tracing state due to a peculiar case of recursion
(details in Makefile comment).
Reported-by: Qian Cai <cai@lca.pw>
Tested-by: Qian Cai <cai@lca.pw>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As it is fine to perform several "peeks" of event data in the ring buffer
via the iterator before moving it forward, do not re-read the event, just
return what was read before. Otherwise, it can cause inconsistent results,
especially when testing multiple CPU buffers to interleave them.
Link: http://lkml.kernel.org/r/20200317213416.592032170@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As the iterator will be reading a live buffer, and if the event being read
is on a page that a writer crosses, it will fail and try again, the
condition in rb_iter_peek() that only allows a retry to happen three times
is no longer valid. Allow rb_iter_peek() to retry more than three times
without killing the ring buffer, but only if rb_iter_head_event() had failed
at least once.
Link: http://lkml.kernel.org/r/20200317213416.452888193@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Have the ring_buffer_iter structure have a place to store an event, such
that it can not be overwritten by a writer, and load it in such a way via
rb_iter_head_event() that it will return NULL and reset the iter to the
start of the current page if a writer updated the page.
Link: http://lkml.kernel.org/r/20200317213416.306959216@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Have the ring_buffer_iter structure contain a page_stamp, such that it can
be used to see if the writer entered the page the iterator is on. When going
to a new page, the iterator will record the time stamp of that page. When
reading events, it can copy the event to an internal buffer on the iterator
(to be implemented later), then check the page's time stamp with its own to
see if the writer entered the page. If so, it will need to try to read the
event again.
Link: http://lkml.kernel.org/r/20200317213416.163549674@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When the ring buffer was first created, the iterator followed the normal
producer/consumer operations where it had both a peek() operation, that just
returned the event at the current location, and a read(), that would return
the event at the current location and also increment the iterator such that
the next peek() or read() will return the next event.
The only use of the ring_buffer_read() is currently to move the iterator to
the next location and nothing now actually reads the event it returns.
Rename this function to its actual use case to ring_buffer_iter_advance(),
which also adds the "iter" part to the name, which is more meaningful. As
the timestamp returned by ring_buffer_read() was never used, there's no
reason that this new version should bother having returning it. It will also
become a void function.
Link: http://lkml.kernel.org/r/20200317213416.018928618@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
It was complained about that when the trace file is read, that the tracing
is disabled, as the iterator expects writing to the buffer it reads is not
updated. Several steps are needed to make the iterator handle a writer,
by testing if things have changed as it reads.
This step is to make ring_buffer_empty() expect the buffer to be changing.
Note if the current location of the iterator is overwritten, then it will
return false as new data is being added. Note, that this means that data
will be skipped.
Link: http://lkml.kernel.org/r/20200317213415.870741809@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In order to have the iterator read the buffer even when it's still updating,
it requires that the ring buffer iterator saves each event in a separate
location outside the ring buffer such that its use is immutable.
There's one use case that saves off the event returned from the ring buffer
interator and calls it again to look at the next event, before going back to
use the first event. As the ring buffer iterator will only have a single
copy, this use case will no longer be supported.
Instead, have the one use case create its own buffer to store the first
event when looking at the next event. This way, when looking at the first
event again, it wont be corrupted by the second read.
Link: http://lkml.kernel.org/r/20200317213415.722539921@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Clang warns:
../kernel/trace/trace.c:9335:33: warning: array comparison always
evaluates to true [-Wtautological-compare]
if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt)
^
1 warning generated.
These are not true arrays, they are linker defined symbols, which are
just addresses. Using the address of operator silences the warning and
does not change the runtime result of the check (tested with some print
statements compiled in with clang + ld.lld and gcc + ld.bfd in QEMU).
Link: http://lkml.kernel.org/r/20200220051011.26113-1-natechancellor@gmail.com
Link: https://github.com/ClangBuiltLinux/linux/issues/893
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2020-03-13
The following pull-request contains BPF updates for your *net-next* tree.
We've added 86 non-merge commits during the last 12 day(s) which contain
a total of 107 files changed, 5771 insertions(+), 1700 deletions(-).
The main changes are:
1) Add modify_return attach type which allows to attach to a function via
BPF trampoline and is run after the fentry and before the fexit programs
and can pass a return code to the original caller, from KP Singh.
2) Generalize BPF's kallsyms handling and add BPF trampoline and dispatcher
objects to be visible in /proc/kallsyms so they can be annotated in
stack traces, from Jiri Olsa.
3) Extend BPF sockmap to allow for UDP next to existing TCP support in order
in order to enable this for BPF based socket dispatch, from Lorenz Bauer.
4) Introduce a new bpftool 'prog profile' command which attaches to existing
BPF programs via fentry and fexit hooks and reads out hardware counters
during that period, from Song Liu. Example usage:
bpftool prog profile id 337 duration 3 cycles instructions llc_misses
4228 run_cnt
3403698 cycles (84.08%)
3525294 instructions # 1.04 insn per cycle (84.05%)
13 llc_misses # 3.69 LLC misses per million isns (83.50%)
5) Batch of improvements to libbpf, bpftool and BPF selftests. Also addition
of a new bpf_link abstraction to keep in particular BPF tracing programs
attached even when the applicaion owning them exits, from Andrii Nakryiko.
6) New bpf_get_current_pid_tgid() helper for tracing to perform PID filtering
and which returns the PID as seen by the init namespace, from Carlos Neira.
7) Refactor of RISC-V JIT code to move out common pieces and addition of a
new RV32G BPF JIT compiler, from Luke Nelson.
8) Add gso_size context member to __sk_buff in order to be able to know whether
a given skb is GSO or not, from Willem de Bruijn.
9) Add a new bpf_xdp_output() helper which reuses XDP's existing perf RB output
implementation but can be called from tracepoint programs, from Eelco Chaudron.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexei Starovoitov says:
====================
pull-request: bpf 2020-03-12
The following pull-request contains BPF updates for your *net* tree.
We've added 12 non-merge commits during the last 8 day(s) which contain
a total of 12 files changed, 161 insertions(+), 15 deletions(-).
The main changes are:
1) Andrii fixed two bugs in cgroup-bpf.
2) John fixed sockmap.
3) Luke fixed x32 jit.
4) Martin fixed two issues in struct_ops.
5) Yonghong fixed bpf_send_signal.
6) Yoshiki fixed BTF enum.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce new helper that reuses existing xdp perf_event output
implementation, but can be called from raw_tracepoint programs
that receive 'struct xdp_buff *' as a tracepoint argument.
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/158348514556.2239.11050972434793741444.stgit@xdp-tutorial
New bpf helper bpf_get_ns_current_pid_tgid,
This helper will return pid and tgid from current task
which namespace matches dev_t and inode number provided,
this will allows us to instrument a process inside a container.
Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200304204157.58695-3-cneirabustos@gmail.com
can break live patching.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXmj5ExQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6quQGAQDO35RBAQDGmpxnSCQPNwrzqokM8p8d
1e1xshwOVnwqgAEA7csC4u1n5Z8ncIl5Pd8ygt4nXeqw4AenHLeZIdhfegc=
=+AeW
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull ftrace fix from Steven Rostedt:
"Have ftrace lookup_rec() return a consistent record otherwise it can
break live patching"
* tag 'trace-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Return the first found result in lookup_rec()
It appears that ip ranges can overlap so. In that case lookup_rec()
returns whatever results it got last even if it found nothing in last
searched page.
This breaks an obscure livepatch late module patching usecase:
- load livepatch
- load the patched module
- unload livepatch
- try to load livepatch again
To fix this return from lookup_rec() as soon as it found the record
containing searched-for ip. This used to be this way prior lookup_rec()
introduction.
Link: http://lkml.kernel.org/r/20200306174317.21699-1-asavkov@redhat.com
Cc: stable@vger.kernel.org
Fixes: 7e16f581a8 ("ftrace: Separate out functionality from ftrace_location_range()")
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-----BEGIN PGP SIGNATURE-----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=xwKl
-----END PGP SIGNATURE-----
Merge tag 'block-5.6-2020-03-07' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"Here are a few fixes that should go into this release. This contains:
- Revert of a bad bcache patch from this merge window
- Removed unused function (Daniel)
- Fixup for the blktrace fix from Jan from this release (Cengiz)
- Fix of deeper level bfqq overwrite in BFQ (Carlo)"
* tag 'block-5.6-2020-03-07' of git://git.kernel.dk/linux-block:
block, bfq: fix overwrite of bfq_group pointer in bfq_find_set_group()
blktrace: fix dereference after null check
Revert "bcache: ignore pending signals when creating gc and allocator thread"
block: Remove used kblockd_schedule_work_on()
test_run.o is not built when CONFIG_NET is not set and
bpf_prog_test_run_tracing being referenced in bpf_trace.o causes the
linker error:
ld: kernel/trace/bpf_trace.o:(.rodata+0x38): undefined reference to
`bpf_prog_test_run_tracing'
Add a __weak function in bpf_trace.c to handle this.
Fixes: da00d2f117 ("bpf: Add test ops for BPF_PROG_TYPE_TRACING")
Signed-off-by: KP Singh <kpsingh@google.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200305220127.29109-1-kpsingh@chromium.org
When experimenting with bpf_send_signal() helper in our production
environment (5.2 based), we experienced a deadlock in NMI mode:
#5 [ffffc9002219f770] queued_spin_lock_slowpath at ffffffff8110be24
#6 [ffffc9002219f770] _raw_spin_lock_irqsave at ffffffff81a43012
#7 [ffffc9002219f780] try_to_wake_up at ffffffff810e7ecd
#8 [ffffc9002219f7e0] signal_wake_up_state at ffffffff810c7b55
#9 [ffffc9002219f7f0] __send_signal at ffffffff810c8602
#10 [ffffc9002219f830] do_send_sig_info at ffffffff810ca31a
#11 [ffffc9002219f868] bpf_send_signal at ffffffff8119d227
#12 [ffffc9002219f988] bpf_overflow_handler at ffffffff811d4140
#13 [ffffc9002219f9e0] __perf_event_overflow at ffffffff811d68cf
#14 [ffffc9002219fa10] perf_swevent_overflow at ffffffff811d6a09
#15 [ffffc9002219fa38] ___perf_sw_event at ffffffff811e0f47
#16 [ffffc9002219fc30] __schedule at ffffffff81a3e04d
#17 [ffffc9002219fc90] schedule at ffffffff81a3e219
#18 [ffffc9002219fca0] futex_wait_queue_me at ffffffff8113d1b9
#19 [ffffc9002219fcd8] futex_wait at ffffffff8113e529
#20 [ffffc9002219fdf0] do_futex at ffffffff8113ffbc
#21 [ffffc9002219fec0] __x64_sys_futex at ffffffff81140d1c
#22 [ffffc9002219ff38] do_syscall_64 at ffffffff81002602
#23 [ffffc9002219ff50] entry_SYSCALL_64_after_hwframe at ffffffff81c00068
The above call stack is actually very similar to an issue
reported by Commit eac9153f2b ("bpf/stackmap: Fix deadlock with
rq_lock in bpf_get_stack()") by Song Liu. The only difference is
bpf_send_signal() helper instead of bpf_get_stack() helper.
The above deadlock is triggered with a perf_sw_event.
Similar to Commit eac9153f2b, the below almost identical reproducer
used tracepoint point sched/sched_switch so the issue can be easily caught.
/* stress_test.c */
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define THREAD_COUNT 1000
char *filename;
void *worker(void *p)
{
void *ptr;
int fd;
char *pptr;
fd = open(filename, O_RDONLY);
if (fd < 0)
return NULL;
while (1) {
struct timespec ts = {0, 1000 + rand() % 2000};
ptr = mmap(NULL, 4096 * 64, PROT_READ, MAP_PRIVATE, fd, 0);
usleep(1);
if (ptr == MAP_FAILED) {
printf("failed to mmap\n");
break;
}
munmap(ptr, 4096 * 64);
usleep(1);
pptr = malloc(1);
usleep(1);
pptr[0] = 1;
usleep(1);
free(pptr);
usleep(1);
nanosleep(&ts, NULL);
}
close(fd);
return NULL;
}
int main(int argc, char *argv[])
{
void *ptr;
int i;
pthread_t threads[THREAD_COUNT];
if (argc < 2)
return 0;
filename = argv[1];
for (i = 0; i < THREAD_COUNT; i++) {
if (pthread_create(threads + i, NULL, worker, NULL)) {
fprintf(stderr, "Error creating thread\n");
return 0;
}
}
for (i = 0; i < THREAD_COUNT; i++)
pthread_join(threads[i], NULL);
return 0;
}
and the following command:
1. run `stress_test /bin/ls` in one windown
2. hack bcc trace.py with the following change:
--- a/tools/trace.py
+++ b/tools/trace.py
@@ -513,6 +513,7 @@ BPF_PERF_OUTPUT(%s);
__data.tgid = __tgid;
__data.pid = __pid;
bpf_get_current_comm(&__data.comm, sizeof(__data.comm));
+ bpf_send_signal(10);
%s
%s
%s.perf_submit(%s, &__data, sizeof(__data));
3. in a different window run
./trace.py -p $(pidof stress_test) t:sched:sched_switch
The deadlock can be reproduced in our production system.
Similar to Song's fix, the fix is to delay sending signal if
irqs is disabled to avoid deadlocks involving with rq_lock.
With this change, my above stress-test in our production system
won't cause deadlock any more.
I also implemented a scale-down version of reproducer in the
selftest (a subsequent commit). With latest bpf-next,
it complains for the following potential deadlock.
[ 32.832450] -> #1 (&p->pi_lock){-.-.}:
[ 32.833100] _raw_spin_lock_irqsave+0x44/0x80
[ 32.833696] task_rq_lock+0x2c/0xa0
[ 32.834182] task_sched_runtime+0x59/0xd0
[ 32.834721] thread_group_cputime+0x250/0x270
[ 32.835304] thread_group_cputime_adjusted+0x2e/0x70
[ 32.835959] do_task_stat+0x8a7/0xb80
[ 32.836461] proc_single_show+0x51/0xb0
...
[ 32.839512] -> #0 (&(&sighand->siglock)->rlock){....}:
[ 32.840275] __lock_acquire+0x1358/0x1a20
[ 32.840826] lock_acquire+0xc7/0x1d0
[ 32.841309] _raw_spin_lock_irqsave+0x44/0x80
[ 32.841916] __lock_task_sighand+0x79/0x160
[ 32.842465] do_send_sig_info+0x35/0x90
[ 32.842977] bpf_send_signal+0xa/0x10
[ 32.843464] bpf_prog_bc13ed9e4d3163e3_send_signal_tp_sched+0x465/0x1000
[ 32.844301] trace_call_bpf+0x115/0x270
[ 32.844809] perf_trace_run_bpf_submit+0x4a/0xc0
[ 32.845411] perf_trace_sched_switch+0x10f/0x180
[ 32.846014] __schedule+0x45d/0x880
[ 32.846483] schedule+0x5f/0xd0
...
[ 32.853148] Chain exists of:
[ 32.853148] &(&sighand->siglock)->rlock --> &p->pi_lock --> &rq->lock
[ 32.853148]
[ 32.854451] Possible unsafe locking scenario:
[ 32.854451]
[ 32.855173] CPU0 CPU1
[ 32.855745] ---- ----
[ 32.856278] lock(&rq->lock);
[ 32.856671] lock(&p->pi_lock);
[ 32.857332] lock(&rq->lock);
[ 32.857999] lock(&(&sighand->siglock)->rlock);
Deadlock happens on CPU0 when it tries to acquire &sighand->siglock
but it has been held by CPU1 and CPU1 tries to grab &rq->lock
and cannot get it.
This is not exactly the callstack in our production environment,
but sympotom is similar and both locks are using spin_lock_irqsave()
to acquire the lock, and both involves rq_lock. The fix to delay
sending signal when irq is disabled also fixed this issue.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200304191104.2796501-1-yhs@fb.com
There was a recent change in blktrace.c that added a RCU protection to
`q->blk_trace` in order to fix a use-after-free issue during access.
However the change missed an edge case that can lead to dereferencing of
`bt` pointer even when it's NULL:
Coverity static analyzer marked this as a FORWARD_NULL issue with CID
1460458.
```
/kernel/trace/blktrace.c: 1904 in sysfs_blk_trace_attr_store()
1898 ret = 0;
1899 if (bt == NULL)
1900 ret = blk_trace_setup_queue(q, bdev);
1901
1902 if (ret == 0) {
1903 if (attr == &dev_attr_act_mask)
>>> CID 1460458: Null pointer dereferences (FORWARD_NULL)
>>> Dereferencing null pointer "bt".
1904 bt->act_mask = value;
1905 else if (attr == &dev_attr_pid)
1906 bt->pid = value;
1907 else if (attr == &dev_attr_start_lba)
1908 bt->start_lba = value;
1909 else if (attr == &dev_attr_end_lba)
```
Added a reassignment with RCU annotation to fix the issue.
Fixes: c780e86dd4 ("blktrace: Protect q->blk_trace with RCU")
Cc: stable@vger.kernel.org
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Cengiz Can <cengiz@kernel.wtf>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The current fexit and fentry tests rely on a different program to
exercise the functions they attach to. Instead of doing this, implement
the test operations for tracing which will also be used for
BPF_MODIFY_RETURN in a subsequent patch.
Also, clean up the fexit test to use the generated skeleton.
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200304191853.1529-7-kpsingh@chromium.org
Commit 567cd4da54 ("ring-buffer: User context bit recursion checking")
added the TRACE_BUFFER bits to be used in the current task's trace_recursion
field. But the final submission of the logic removed the use of those bits,
but never removed the bits themselves (they were never used in upstream
Linux). These can be safely removed.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The hwlat tracer runs a loop of width time during a given window. It then
reports the max latency over a given threshold and records a timestamp. But
this timestamp is the time after the width has finished, and not the time it
actually triggered.
Record the actual time when the latency was greater than the threshold as
well as the number of times it was greater in a given width per window.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Alexei Starovoitov says:
====================
pull-request: bpf-next 2020-02-28
The following pull-request contains BPF updates for your *net-next* tree.
We've added 41 non-merge commits during the last 7 day(s) which contain
a total of 49 files changed, 1383 insertions(+), 499 deletions(-).
The main changes are:
1) BPF and Real-Time nicely co-exist.
2) bpftool feature improvements.
3) retrieve bpf_sk_storage via INET_DIAG.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The mptcp conflict was overlapping additions.
The SMC conflict was an additional and removal happening at the same
time.
Signed-off-by: David S. Miller <davem@davemloft.net>
Change in API of bootconfig (before it comes live in a release)
- Have a magic value "BOOTCONFIG" in initrd to know a bootconfig exists
- Set CONFIG_BOOT_CONFIG to 'n' by default
- Show error if "bootconfig" on cmdline but not compiled in
- Prevent redefining the same value
- Have a way to append values
- Added a SELECT BLK_DEV_INITRD to fix a build failure
Synthetic event fixes:
- Switch to raw_smp_processor_id() for recording CPU value in preempt
section. (No care for what the value actually is)
- Fix samples always recording u64 values
- Fix endianess
- Check number of values matches number of fields
- Fix a printing bug
Fix of trace_printk() breaking postponed start up tests
Make a function static that is only used in a single file.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXlW4vxQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qtioAP0WLEm3dWO0z3321h/a0DSshC+Bslu3
HDPTsGVGrXmvggEA/lr1ikRHd8PsO7zW8BfaZMxoXaTqXiuSrzEWxnMlFw0=
=O8PM
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing and bootconfig updates:
"Fixes and changes to bootconfig before it goes live in a release.
Change in API of bootconfig (before it comes live in a release):
- Have a magic value "BOOTCONFIG" in initrd to know a bootconfig
exists
- Set CONFIG_BOOT_CONFIG to 'n' by default
- Show error if "bootconfig" on cmdline but not compiled in
- Prevent redefining the same value
- Have a way to append values
- Added a SELECT BLK_DEV_INITRD to fix a build failure
Synthetic event fixes:
- Switch to raw_smp_processor_id() for recording CPU value in preempt
section. (No care for what the value actually is)
- Fix samples always recording u64 values
- Fix endianess
- Check number of values matches number of fields
- Fix a printing bug
Fix of trace_printk() breaking postponed start up tests
Make a function static that is only used in a single file"
* tag 'trace-v5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
bootconfig: Fix CONFIG_BOOTTIME_TRACING dependency issue
bootconfig: Add append value operator support
bootconfig: Prohibit re-defining value on same key
bootconfig: Print array as multiple commands for legacy command line
bootconfig: Reject subkey and value on same parent key
tools/bootconfig: Remove unneeded error message silencer
bootconfig: Add bootconfig magic word for indicating bootconfig explicitly
bootconfig: Set CONFIG_BOOT_CONFIG=n by default
tracing: Clear trace_state when starting trace
bootconfig: Mark boot_config_checksum() static
tracing: Disable trace_printk() on post poned tests
tracing: Have synthetic event test use raw_smp_processor_id()
tracing: Fix number printing bug in print_synth_event()
tracing: Check that number of vals matches number of synth event fields
tracing: Make synth_event trace functions endian-correct
tracing: Make sure synth_event_trace() example always uses u64
Since commit d8a953ddde ("bootconfig: Set CONFIG_BOOT_CONFIG=n by
default") also changed the CONFIG_BOOTTIME_TRACING to select
CONFIG_BOOT_CONFIG to show the boot-time tracing on the menu,
it introduced wrong dependencies with BLK_DEV_INITRD as below.
WARNING: unmet direct dependencies detected for BOOT_CONFIG
Depends on [n]: BLK_DEV_INITRD [=n]
Selected by [y]:
- BOOTTIME_TRACING [=y] && TRACING_SUPPORT [=y] && FTRACE [=y] && TRACING [=y]
This makes the CONFIG_BOOT_CONFIG selects CONFIG_BLK_DEV_INITRD to
fix this error and make CONFIG_BOOTTIME_TRACING=n by default, so
that both boot-time tracing and boot configuration off but those
appear on the menu list.
Link: http://lkml.kernel.org/r/158264140162.23842.11237423518607465535.stgit@devnote2
Fixes: d8a953ddde ("bootconfig: Set CONFIG_BOOT_CONFIG=n by default")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Compiled-tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
KASAN is reporting that __blk_add_trace() has a use-after-free issue
when accessing q->blk_trace. Indeed the switching of block tracing (and
thus eventual freeing of q->blk_trace) is completely unsynchronized with
the currently running tracing and thus it can happen that the blk_trace
structure is being freed just while __blk_add_trace() works on it.
Protect accesses to q->blk_trace by RCU during tracing and make sure we
wait for the end of RCU grace period when shutting down tracing. Luckily
that is rare enough event that we can afford that. Note that postponing
the freeing of blk_trace to an RCU callback should better be avoided as
it could have unexpected user visible side-effects as debugfs files
would be still existing for a short while block tracing has been shut
down.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=205711
CC: stable@vger.kernel.org
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reported-by: Tristan Madani <tristmd@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Similar to __bpf_trace_run this is redundant because __bpf_trace_run() is
invoked from a trace point via __DO_TRACE() which already disables
preemption _before_ invoking any of the functions which are attached to a
trace point.
Remove it and add a cant_sleep() check.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200224145643.059995527@linutronix.de
trace_call_bpf() no longer disables preemption on its own.
All callers of this function has to do it explicitly.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
All callers are built in. No point to export this.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
__bpf_trace_run() disables preemption around the BPF_PROG_RUN() invocation.
This is redundant because __bpf_trace_run() is invoked from a trace point
via __DO_TRACE() which already disables preemption _before_ invoking any of
the functions which are attached to a trace point.
Remove it and add a cant_sleep() check.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200224145642.847220186@linutronix.de
Set CONFIG_BOOT_CONFIG=n by default. This also warns
user if CONFIG_BOOT_CONFIG=n but "bootconfig" is given
in the kernel command line.
Link: http://lkml.kernel.org/r/158220111291.26565.9036889083940367969.stgit@devnote2
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Clear trace_state data structure when starting trace
in __synth_event_trace_start() internal function.
Currently trace_state is initialized only in the
synth_event_trace_start() API, but the trace_state
in synth_event_trace() and synth_event_trace_array()
are on the stack without initialization.
This means those APIs will see wrong parameters and
wil skip closing process in __synth_event_trace_end()
because trace_state->disabled may be !0.
Link: http://lkml.kernel.org/r/158193315899.8868.1781259176894639952.stgit@devnote2
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The tracing seftests checks various aspects of the tracing infrastructure,
and one is filtering. If trace_printk() is active during a self test, it can
cause the filtering to fail, which will disable that part of the trace.
To keep the selftests from failing because of trace_printk() calls,
trace_printk() checks the variable tracing_selftest_running, and if set, it
does not write to the tracing buffer.
As some tracers were registered earlier in boot, the selftest they triggered
would fail because not all the infrastructure was set up for the full
selftest. Thus, some of the tests were post poned to when their
infrastructure was ready (namely file system code). The postpone code did
not set the tracing_seftest_running variable, and could fail if a
trace_printk() was added and executed during their run.
Cc: stable@vger.kernel.org
Fixes: 9afecfbb95 ("tracing: Postpone tracer start-up tests till the system is more robust")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The test code that tests synthetic event creation pushes in as one of its
test fields the current CPU using "smp_processor_id()". As this is just
something to see if the value is correctly passed in, and the actual CPU
used does not matter, use raw_smp_processor_id(), otherwise with debug
preemption enabled, a warning happens as the smp_processor_id() is called
without preemption enabled.
Link: http://lkml.kernel.org/r/20200220162950.35162579@gandalf.local.home
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fix a varargs-related bug in print_synth_event() which resulted in
strange output and oopses on 32-bit x86 systems. The problem is that
trace_seq_printf() expects the varargs to match the format string, but
print_synth_event() was always passing u64 values regardless. This
results in unspecified behavior when unpacking with va_arg() in
trace_seq_printf().
Add a function that takes the size into account when calling
trace_seq_printf().
Before:
modprobe-1731 [003] .... 919.039758: gen_synth_test: next_pid_field=777(null)next_comm_field=hula hoops ts_ns=1000000 ts_ms=1000 cpu=3(null)my_string_field=thneed my_int_field=598(null)
After:
insmod-1136 [001] .... 36.634590: gen_synth_test: next_pid_field=777 next_comm_field=hula hoops ts_ns=1000000 ts_ms=1000 cpu=1 my_string_field=thneed my_int_field=598
Link: http://lkml.kernel.org/r/a9b59eb515dbbd7d4abe53b347dccf7a8e285657.1581720155.git.zanussi@kernel.org
Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Commit 7276531d4036('tracing: Consolidate trace() functions')
inadvertently dropped the synth_event_trace() and
synth_event_trace_array() checks that verify the number of values
passed in matches the number of fields in the synthetic event being
traced, so add them back.
Link: http://lkml.kernel.org/r/32819cac708714693669e0dfe10fe9d935e94a16.1581720155.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
synth_event_trace(), synth_event_trace_array() and
__synth_event_add_val() write directly into the trace buffer and need
to take endianness into account, like trace_event_raw_event_synth()
does.
Link: http://lkml.kernel.org/r/2011354355e405af9c9d28abba430d1f5ff7771a.1581720155.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
synth_event_trace() is the varargs version of synth_event_trace_array(),
which takes an array of u64, as do synth_event_add_val() et al.
To not only be consistent with those, but also to address the fact
that synth_event_trace() expects every arg to be of the same type
since it doesn't also pass in e.g. a format string, the caller needs
to make sure all args are of the same type, u64. u64 is used because
it needs to accomodate the largest type available in synthetic events,
which is u64.
This fixes the bug reported by the kernel test robot/Rong Chen.
Link: https://lore.kernel.org/lkml/20200212113444.GS12867@shao2-debian/
Link: http://lkml.kernel.org/r/894c4e955558b521210ee0642ba194a9e603354c.1581720155.git.zanussi@kernel.org
Fixes: 9fe41efaca ("tracing: Add synth event generation test module")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Branch records are a CPU feature that can be configured to record
certain branches that are taken during code execution. This data is
particularly interesting for profile guided optimizations. perf has had
branch record support for a while but the data collection can be a bit
coarse grained.
We (Facebook) have seen in experiments that associating metadata with
branch records can improve results (after postprocessing). We generally
use bpf_probe_read_*() to get metadata out of userspace. That's why bpf
support for branch records is useful.
Aside from this particular use case, having branch data available to bpf
progs can be useful to get stack traces out of userspace applications
that omit frame pointers.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200218030432.4600-2-dxu@dxuuu.xyz
bpf_perf_event_read_value() is NMI safe. Enable it for all BPF programs.
This can be used in fentry/fexit to profile BPF program and individual
kernel function with hardware counters.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200214234146.2910011-1-songliubraving@fb.com
- Fix an uninitialized variable
- Fix compile bug to bootconfig userspace tool (in tools directory)
- Suppress some error messages of bootconfig userspace tool
- Remove unneded CONFIG_LIBXBC from bootconfig
- Allocate bootconfig xbc_nodes dynamically.
To ease complaints about taking up static memory at boot up
- Use of parse_args() to parse bootconfig instead of strstr() usage
Prevents issues of double quotes containing the interested string
- Fix missing ring_buffer_nest_end() on synthetic event error path
- Return zero not -EINVAL on soft disabled synthetic event
(soft disabling must be the same as hard disabling, which returns zero)
- Consolidate synthetic event code (remove duplicate code)
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXkMTwRQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qnJQAQD5aKiD6jx+zGtLsFTuZMcEGvhhUuJ6
oUaSvhKO3UqezwD/V5avKuuC0wWt//gOWDY+0+4QNjmvn1GLnaNYohs6fg0=
=NLT9
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Various fixes:
- Fix an uninitialized variable
- Fix compile bug to bootconfig userspace tool (in tools directory)
- Suppress some error messages of bootconfig userspace tool
- Remove unneded CONFIG_LIBXBC from bootconfig
- Allocate bootconfig xbc_nodes dynamically. To ease complaints about
taking up static memory at boot up
- Use of parse_args() to parse bootconfig instead of strstr() usage
Prevents issues of double quotes containing the interested string
- Fix missing ring_buffer_nest_end() on synthetic event error path
- Return zero not -EINVAL on soft disabled synthetic event (soft
disabling must be the same as hard disabling, which returns zero)
- Consolidate synthetic event code (remove duplicate code)"
* tag 'trace-v5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Consolidate trace() functions
tracing: Don't return -EINVAL when tracing soft disabled synth events
tracing: Add missing nest end to synth_event_trace_start() error case
tools/bootconfig: Suppress non-error messages
bootconfig: Allocate xbc_nodes array dynamically
bootconfig: Use parse_args() to find bootconfig and '--'
tracing/kprobe: Fix uninitialized variable bug
bootconfig: Remove unneeded CONFIG_LIBXBC
tools/bootconfig: Fix wrong __VA_ARGS__ usage
Move the checking, buffer reserve and buffer commit code in
synth_event_trace_start/end() into inline functions
__synth_event_trace_start/end() so they can also be used by
synth_event_trace() and synth_event_trace_array(), and then have all
those functions use them.
Also, change synth_event_trace_state.enabled to disabled so it only
needs to be set if the event is disabled, which is not normally the
case.
Link: http://lkml.kernel.org/r/b1f3108d0f450e58192955a300e31d0405ab4149.1581374549.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
There's no reason to return -EINVAL when tracing a synthetic event if
it's soft disabled - treat it the same as if it were hard disabled and
return normally.
Have synth_event_trace() and synth_event_trace_array() just return
normally, and have synth_event_trace_start set the trace state to
disabled and return.
Link: http://lkml.kernel.org/r/df5d02a1625aff97c9866506c5bada6a069982ba.1581374549.git.zanussi@kernel.org
Fixes: 8dcc53ad95 ("tracing: Add synth_event_trace() and related functions")
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If the ring_buffer reserve in synth_event_trace_start() fails, the
matching ring_buffer_nest_end() should be called in the error code,
since nothing else will ever call it in this case.
Link: http://lkml.kernel.org/r/20abc444b3eeff76425f895815380abe7aa53ff8.1581374549.git.zanussi@kernel.org
Fixes: 8dcc53ad95 ("tracing: Add synth_event_trace() and related functions")
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
There is a potential execution path in which variable *ret* is returned
without being properly initialized, previously.
Fix this by initializing variable *ret* to 0.
Link: http://lkml.kernel.org/r/20200205223404.GA3379@embeddedor
Addresses-Coverity-ID: 1491142 ("Uninitialized scalar variable")
Fixes: 2a588dd1d5 ("tracing: Add kprobe event command generation functions")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
- Added new "bootconfig".
Looks for a file appended to initrd to add boot config options.
This has been discussed thoroughly at Linux Plumbers.
Very useful for adding kprobes at bootup.
Only enabled if "bootconfig" is on the real kernel command line.
- Created dynamic event creation.
Merges common code between creating synthetic events and
kprobe events.
- Rename perf "ring_buffer" structure to "perf_buffer"
- Rename ftrace "ring_buffer" structure to "trace_buffer"
Had to rename existing "trace_buffer" to "array_buffer"
- Allow trace_printk() to work withing (some) tracing code.
- Sort of tracing configs to be a little better organized
- Fixed bug where ftrace_graph hash was not being protected properly
- Various other small fixes and clean ups
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXjtAURQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qshOAQDzopQmvAVrrI6oogghr8JQA30Z2yqT
i+Ld7vPWL2MV9wEA1S+zLGDSYrj8f/vsCq6BxRYT1ApO+YtmY6LTXiUejwg=
=WNds
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Added new "bootconfig".
This looks for a file appended to initrd to add boot config options,
and has been discussed thoroughly at Linux Plumbers.
Very useful for adding kprobes at bootup.
Only enabled if "bootconfig" is on the real kernel command line.
- Created dynamic event creation.
Merges common code between creating synthetic events and kprobe
events.
- Rename perf "ring_buffer" structure to "perf_buffer"
- Rename ftrace "ring_buffer" structure to "trace_buffer"
Had to rename existing "trace_buffer" to "array_buffer"
- Allow trace_printk() to work withing (some) tracing code.
- Sort of tracing configs to be a little better organized
- Fixed bug where ftrace_graph hash was not being protected properly
- Various other small fixes and clean ups
* tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits)
bootconfig: Show the number of nodes on boot message
tools/bootconfig: Show the number of bootconfig nodes
bootconfig: Add more parse error messages
bootconfig: Use bootconfig instead of boot config
ftrace: Protect ftrace_graph_hash with ftrace_sync
ftrace: Add comment to why rcu_dereference_sched() is open coded
tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
tracing: Annotate ftrace_graph_hash pointer with __rcu
bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline
tracing: Use seq_buf for building dynevent_cmd string
tracing: Remove useless code in dynevent_arg_pair_add()
tracing: Remove check_arg() callbacks from dynevent args
tracing: Consolidate some synth_event_trace code
tracing: Fix now invalid var_ref_vals assumption in trace action
tracing: Change trace_boot to use synth_event interface
tracing: Move tracing selftests to bottom of menu
tracing: Move mmio tracer config up with the other tracers
tracing: Move tracing test module configs together
tracing: Move all function tracing configs together
tracing: Documentation for in-kernel synthetic event API
...
As function_graph tracer can run when RCU is not "watching", it can not be
protected by synchronize_rcu() it requires running a task on each CPU before
it can be freed. Calling schedule_on_each_cpu(ftrace_sync) needs to be used.
Link: https://lore.kernel.org/r/20200205131110.GT2935@paulmck-ThinkPad-P72
Cc: stable@vger.kernel.org
Fixes: b9b0c831be ("ftrace: Convert graph filter to use hash tables")
Reported-by: "Paul E. McKenney" <paulmck@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Because the function graph tracer can execute in sections where RCU is not
"watching", the rcu_dereference_sched() for the has needs to be open coded.
This is fine because the RCU "flavor" of the ftrace hash is protected by
its own RCU handling (it does its own little synchronization on every CPU
and does not rely on RCU sched).
Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fix following instances of sparse error
kernel/trace/ftrace.c:5667:29: error: incompatible types in comparison
kernel/trace/ftrace.c:5813:21: error: incompatible types in comparison
kernel/trace/ftrace.c:5868:36: error: incompatible types in comparison
kernel/trace/ftrace.c:5870:25: error: incompatible types in comparison
Use rcu_dereference_protected to dereference the newly annotated pointer.
Link: http://lkml.kernel.org/r/20200205055701.30195-1-frextrite@gmail.com
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fix following instances of sparse error
kernel/trace/ftrace.c:5664:29: error: incompatible types in comparison
kernel/trace/ftrace.c:5785:21: error: incompatible types in comparison
kernel/trace/ftrace.c:5864:36: error: incompatible types in comparison
kernel/trace/ftrace.c:5866:25: error: incompatible types in comparison
Use rcu_dereference_protected to access the __rcu annotated pointer.
Link: http://lkml.kernel.org/r/20200201072703.17330-1-frextrite@gmail.com
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull vfs recursive removal updates from Al Viro:
"We have quite a few places where synthetic filesystems do an
equivalent of 'rm -rf', with varying amounts of code duplication,
wrong locking, etc. That really ought to be a library helper.
Only debugfs (and very similar tracefs) are converted here - I have
more conversions, but they'd never been in -next, so they'll have to
wait"
* 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
simple_recursive_removal(): kernel-side rm -rf for ramfs-style filesystems
The dynevent_cmd commands that build up the command string don't need
to do that themselves - there's a seq_buf facility that does pretty
much the same thing those command are doing manually, so use it
instead.
Link: http://lkml.kernel.org/r/eb8a6e835c964d0ab8a38cbf5ffa60746b54a465.1580506712.git.zanussi@kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
It's kind of strange to have check_arg() callbacks as part of the arg
objects themselves; it makes more sense to just pass these in when the
args are added instead.
Remove the check_arg() callbacks from those objects which also means
removing the check_arg() args from the init functions, adding them to
the add functions and fixing up existing callers.
Link: http://lkml.kernel.org/r/c7708d6f177fcbe1a36b6e4e8e150907df0fa5d2.1580506712.git.zanussi@kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The synth_event trace code contains some almost identical functions
and some small functions that are called only once - consolidate the
common code into single functions and fold in the small functions to
simplify the code overall.
Link: http://lkml.kernel.org/r/d1c8d8ad124a653b7543afe801d38c199ca5c20e.1580506712.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The patch 'tracing: Fix histogram code when expression has same var as
value' added code to return an existing variable reference when
creating a new variable reference, which resulted in var_ref_vals
slots being reused instead of being duplicated.
The implementation of the trace action assumes that the end of the
var_ref_vals array starting at action_data.var_ref_idx corresponds to
the values that will be assigned to the trace params. The patch
mentioned above invalidates that assumption, which means that each
param needs to explicitly specify its index into var_ref_vals.
This fix changes action_data.var_ref_idx to an array of var ref
indexes to account for that.
Link: https://lore.kernel.org/r/1580335695.6220.8.camel@kernel.org
Fixes: 8bcebc77e8 ("tracing: Fix histogram code when expression has same var as value")
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Have trace_boot_add_synth_event() use the synth_event interface.
Also, rename synth_event_run_cmd() to synth_event_run_command() now
that trace_boot's version is gone.
Link: http://lkml.kernel.org/r/94f1fa0e31846d0bddca916b8663404b20559e34.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Move all the tracing selftest configs to the bottom of the tracing menu.
There's no reason for them to be interspersed throughout.
Also, move the bootconfig menu to the top.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Move the config that enables the mmiotracer with the other tracers such that
all the tracers are together.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The MMIO test module was by itself, move it to the other test modules. Also,
add the text "Test module" to PREEMPTIRQ_DELAY_TEST as that create a test
module as well.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The features that depend on the function tracer were spread out through the
tracing menu, pull them together as it is easier to manage.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a test module that checks the basic functionality of the in-kernel
kprobe event command generation API by creating kprobe events from a
module.
Link: http://lkml.kernel.org/r/97e502b204f9dba948e3fa3a4315448298218787.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Have trace_boot_add_kprobe_event() use the kprobe_event interface.
Also, rename kprobe_event_run_cmd() to kprobe_event_run_command() now
that trace_boot's version is gone.
Link: http://lkml.kernel.org/r/af5429d11291ab1e9a85a0ff944af3b2bcf193c7.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add functions used to generate kprobe event commands, built on top of
the dynevent_cmd interface.
kprobe_event_gen_cmd_start() is used to create a kprobe event command
using a variable arg list, and kretprobe_event_gen_cmd_start() does
the same for kretprobe event commands. kprobe_event_add_fields() can
be used to add single fields one by one or as a group. Once all
desired fields are added, kprobe_event_gen_cmd_end() or
kretprobe_event_gen_cmd_end() respectively are used to actually
execute the command and create the event.
Link: http://lkml.kernel.org/r/95cc4696502bb6017f9126f306a45ad19b4cc14f.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a test module that checks the basic functionality of the in-kernel
synthetic event generation API by generating and tracing synthetic
events from a module.
Link: http://lkml.kernel.org/r/fcb4dd9eb9eefb70ab20538d3529d51642389664.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add an exported function named synth_event_trace(), allowing modules
or other kernel code to trace synthetic events.
Also added are several functions that allow the same functionality to
be broken out in a piecewise fashion, which are useful in situations
where tracing an event from a full array of values would be
cumbersome. Those functions are synth_event_trace_start/end() and
synth_event_add_(next)_val().
Link: http://lkml.kernel.org/r/7a84de5f1854acf4144b57efe835ca645afa764f.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add functions used to generate synthetic event commands, built on top
of the dynevent_cmd interface.
synth_event_gen_cmd_start() is used to create a synthetic event
command using a variable arg list and
synth_event_gen_cmd_array_start() does the same thing but using an
array of field descriptors. synth_event_add_field(),
synth_event_add_field_str() and synth_event_add_fields() can be used
to add single fields one by one or as a group. Once all desired
fields are added, synth_event_gen_cmd_end() is used to actually
execute the command and create the event.
synth_event_create() does everything, including creating the event, in
a single call.
Link: http://lkml.kernel.org/r/38fef702fad5ef208009f459552f34a94befd860.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add an interface used to build up dynamic event creation commands,
such as synthetic and kprobe events. Interfaces specific to those
particular types of events and others can be built on top of this
interface.
Command creation is started by first using the dynevent_cmd_init()
function to initialize the dynevent_cmd object. Following that, args
are appended and optionally checked by the dynevent_arg_add() and
dynevent_arg_pair_add() functions, which use objects representing
arguments and pairs of arguments, initialized respectively by
dynevent_arg_init() and dynevent_arg_pair_init(). Finally, once all
args have been successfully added, the command is finalized and
actually created using dynevent_create().
The code here for actually printing into the dyn_event->cmd buffer
using snprintf() etc was adapted from v4 of Masami's 'tracing/boot:
Add synthetic event support' patch.
Link: http://lkml.kernel.org/r/1f65fa44390b6f238f6036777c3784ced1dcc6a0.1580323897.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
create_or_delete_synth_event() contains code to delete a synthetic
event, which would be useful on its own - specifically, it would be
useful to allow event-creating modules to call it separately.
Separate out the delete code from that function and create an exported
function named synth_event_delete().
Link: http://lkml.kernel.org/r/050db3b06df7f0a4b8a2922da602d1d879c7c1c2.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a function to get an event file and prevent it from going away on
module or instance removal.
trace_get_event_file() will find an event file in a given instance (if
instance is NULL, it assumes the top trace array) and return it,
pinning the instance's trace array as well as the event's module, if
applicable, so they won't go away while in use.
trace_put_event_file() does the matching release.
Link: http://lkml.kernel.org/r/bb31ac4bdda168d5ed3c4b5f5a4c8f633e8d9118.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
[ Moved trace_array_put() to end of trace_put_event_file() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a new trace_array_find() function that can be used to find a trace
array given the instance name, and replace existing code that does the
same thing with it. Also add trace_array_find_get() which does the
same but returns the trace array after upping its refcount.
Also make both available for use outside of trace.c.
Link: http://lkml.kernel.org/r/cb68528c975eba95bee4561ac67dd1499423b2e5.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.
Without patch:
# dd bs=30 skip=1 if=/sys/kernel/tracing/events/sched/sched_switch/trigger
dd: /sys/kernel/tracing/events/sched/sched_switch/trigger: cannot skip to specified offset
n traceoff snapshot stacktrace enable_event disable_event enable_hist disable_hist hist
# Available triggers:
# traceon traceoff snapshot stacktrace enable_event disable_event enable_hist disable_hist hist
6+1 records in
6+1 records out
206 bytes copied, 0.00027916 s, 738 kB/s
Notice the printing of "# Available triggers:..." after the line.
With the patch:
# dd bs=30 skip=1 if=/sys/kernel/tracing/events/sched/sched_switch/trigger
dd: /sys/kernel/tracing/events/sched/sched_switch/trigger: cannot skip to specified offset
n traceoff snapshot stacktrace enable_event disable_event enable_hist disable_hist hist
2+1 records in
2+1 records out
88 bytes copied, 0.000526867 s, 167 kB/s
It only prints the end of the file, and does not restart.
Link: http://lkml.kernel.org/r/3c35ee24-dd3a-8119-9c19-552ed253388a@virtuozzo.comhttps://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.
Link: http://lkml.kernel.org/r/7ad85b22-1866-977c-db17-88ac438bc764@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
[ This is not a bug fix, it just makes it "technically correct"
which is why I applied it. NULL is only returned on an anomaly
which triggers a WARN_ON ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.
Without patch:
# dd bs=4 skip=1 if=/sys/kernel/tracing/set_ftrace_pid
dd: /sys/kernel/tracing/set_ftrace_pid: cannot skip to specified offset
id
no pid
2+1 records in
2+1 records out
10 bytes copied, 0.000213285 s, 46.9 kB/s
Notice the "id" followed by "no pid".
With the patch:
# dd bs=4 skip=1 if=/sys/kernel/tracing/set_ftrace_pid
dd: /sys/kernel/tracing/set_ftrace_pid: cannot skip to specified offset
id
0+1 records in
0+1 records out
3 bytes copied, 0.000202112 s, 14.8 kB/s
Notice that it only prints "id" and not the "no pid" afterward.
Link: http://lkml.kernel.org/r/4f87c6ad-f114-30bb-8506-c32274ce2992@virtuozzo.comhttps://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reading the sched_cmdline_ref and sched_tgid_ref initial state within
tracing_start_sched_switch without holding the sched_register_mutex is
racy against concurrent updates, which can lead to tracepoint probes
being registered more than once (and thus trigger warnings within
tracepoint.c).
[ May be the fix for this bug ]
Link: https://lore.kernel.org/r/000000000000ab6f84056c786b93@google.com
Link: http://lkml.kernel.org/r/20190817141208.15226-1-mathieu.desnoyers@efficios.com
Cc: stable@vger.kernel.org
CC: Steven Rostedt (VMware) <rostedt@goodmis.org>
CC: Joel Fernandes (Google) <joel@joelfernandes.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Paul E. McKenney <paulmck@linux.ibm.com>
Reported-by: syzbot+774fddf07b7ab29a1e55@syzkaller.appspotmail.com
Fixes: d914ba37d7 ("tracing: Add support for recording tgid of tasks")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Move external function declarations into kernel/trace/trace.h
from trace_boot.c for tracing subsystem internal use.
Link: http://lkml.kernel.org/r/158029060405.12381.11944554430359702545.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The 'hist:' prefix gets stripped from the command text during command
processing, but should be added back when displaying the command
during error processing.
Not only because it's what should be displayed but also because not
having it means the test cases fail because the caret is miscalculated
by the length of the prefix string.
Link: http://lkml.kernel.org/r/449df721f560042e22382f67574bcc5b4d830d3d.1561743018.git.zanussi@kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In the process of adding better error messages for sorting, I realized
that strsep was being used incorrectly and some of the error paths I
was expecting to be hit weren't and just fell through to the common
invalid key error case.
It also became obvious that for keyword assignments, it wasn't
necessary to save the full assignment and reparse it later, and having
a common empty-assignment check would also make more sense in terms of
error processing.
Change the code to fix these problems and simplify it for new error
message changes in a subsequent patch.
Link: http://lkml.kernel.org/r/1c3ef0b6655deaf345f6faee2584a0298ac2d743.1561743018.git.zanussi@kernel.org
Fixes: e62347d245 ("tracing: Add hist trigger support for user-defined sorting ('sort=' param)")
Fixes: 7ef224d1d0 ("tracing: Add 'hist' event trigger command")
Fixes: a4072fe85b ("tracing: Add a clock attribute for hist triggers")
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
or user space. But the creating of the event format file only checks for
"string" to display string formats. "ustring" must also be handled.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXi8JRxQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qvaiAP943Srl0C1NHuKtJGHpYkgHJRt4mPFO
569Wx82a2ODH4AEA/D8uda0+p0wJB/uDnd/VyhTeb1nAjqzhx4pfGPNjaw8=
=lu3h
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Kprobe events added 'ustring' to distinguish reading strings from
kernel space or user space.
But the creating of the event format file only checks for 'string' to
display string formats. 'ustring' must also be handled"
* tag 'trace-v5.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/kprobes: Have uname use __get_str() in print_fmt
Pull networking updates from David Miller:
1) Add WireGuard
2) Add HE and TWT support to ath11k driver, from John Crispin.
3) Add ESP in TCP encapsulation support, from Sabrina Dubroca.
4) Add variable window congestion control to TIPC, from Jon Maloy.
5) Add BCM84881 PHY driver, from Russell King.
6) Start adding netlink support for ethtool operations, from Michal
Kubecek.
7) Add XDP drop and TX action support to ena driver, from Sameeh
Jubran.
8) Add new ipv4 route notifications so that mlxsw driver does not have
to handle identical routes itself. From Ido Schimmel.
9) Add BPF dynamic program extensions, from Alexei Starovoitov.
10) Support RX and TX timestamping in igc, from Vinicius Costa Gomes.
11) Add support for macsec HW offloading, from Antoine Tenart.
12) Add initial support for MPTCP protocol, from Christoph Paasch,
Matthieu Baerts, Florian Westphal, Peter Krystad, and many others.
13) Add Octeontx2 PF support, from Sunil Goutham, Geetha sowjanya, Linu
Cherian, and others.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1469 commits)
net: phy: add default ARCH_BCM_IPROC for MDIO_BCM_IPROC
udp: segment looped gso packets correctly
netem: change mailing list
qed: FW 8.42.2.0 debug features
qed: rt init valid initialization changed
qed: Debug feature: ilt and mdump
qed: FW 8.42.2.0 Add fw overlay feature
qed: FW 8.42.2.0 HSI changes
qed: FW 8.42.2.0 iscsi/fcoe changes
qed: Add abstraction for different hsi values per chip
qed: FW 8.42.2.0 Additional ll2 type
qed: Use dmae to write to widebus registers in fw_funcs
qed: FW 8.42.2.0 Parser offsets modified
qed: FW 8.42.2.0 Queue Manager changes
qed: FW 8.42.2.0 Expose new registers and change windows
qed: FW 8.42.2.0 Internal ram offsets modifications
MAINTAINERS: Add entry for Marvell OcteonTX2 Physical Function driver
Documentation: net: octeontx2: Add RVU HW and drivers overview
octeontx2-pf: ethtool RSS config support
octeontx2-pf: Add basic ethtool support
...
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- Ftrace is one of the last W^X violators (after this only KLP is
left). These patches move it over to the generic text_poke()
interface and thereby get rid of this oddity. This requires a
surprising amount of surgery, by Peter Zijlstra.
- x86/AMD PMUs: add support for 'Large Increment per Cycle Events' to
count certain types of events that have a special, quirky hw ABI
(by Kim Phillips)
- kprobes fixes by Masami Hiramatsu
Lots of tooling updates as well, the following subcommands were
updated: annotate/report/top, c2c, clang, record, report/top TUI,
sched timehist, tests; plus updates were done to the gtk ui, libperf,
headers and the parser"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
perf/x86/amd: Add support for Large Increment per Cycle Events
perf/x86/amd: Constrain Large Increment per Cycle events
perf/x86/intel/rapl: Add Comet Lake support
tracing: Initialize ret in syscall_enter_define_fields()
perf header: Use last modification time for timestamp
perf c2c: Fix return type for histogram sorting comparision functions
perf beauty sockaddr: Fix augmented syscall format warning
perf/ui/gtk: Fix gtk2 build
perf ui gtk: Add missing zalloc object
perf tools: Use %define api.pure full instead of %pure-parser
libperf: Setup initial evlist::all_cpus value
perf report: Fix no libunwind compiled warning break s390 issue
perf tools: Support --prefix/--prefix-strip
perf report: Clarify in help that --children is default
tools build: Fix test-clang.cpp with Clang 8+
perf clang: Fix build with Clang 9
kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic
tools lib: Fix builds when glibc contains strlcpy()
perf report/top: Make 'e' visible in the help and make it toggle showing callchains
perf report/top: Do not offer annotation for symbols without samples
...
Thomas Richter reported:
> Test case 66 'Use vfs_getname probe to get syscall args filenames'
> is broken on s390, but works on x86. The test case fails with:
>
> [root@m35lp76 perf]# perf test -F 66
> 66: Use vfs_getname probe to get syscall args filenames
> :Recording open file:
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.004 MB /tmp/__perf_test.perf.data.TCdYj\
> (20 samples) ]
> Looking at perf.data file for vfs_getname records for the file we touched:
> FAILED!
> [root@m35lp76 perf]#
The root cause was the print_fmt of the kprobe event that referenced the
"ustring"
> Setting up the kprobe event using perf command:
>
> # ./perf probe "vfs_getname=getname_flags:72 pathname=filename:ustring"
>
> generates this format file:
> [root@m35lp76 perf]# cat /sys/kernel/debug/tracing/events/probe/\
> vfs_getname/format
> name: vfs_getname
> ID: 1172
> format:
> field:unsigned short common_type; offset:0; size:2; signed:0;
> field:unsigned char common_flags; offset:2; size:1; signed:0;
> field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
> field:int common_pid; offset:4; size:4; signed:1;
>
> field:unsigned long __probe_ip; offset:8; size:8; signed:0;
> field:__data_loc char[] pathname; offset:16; size:4; signed:1;
>
> print fmt: "(%lx) pathname=\"%s\"", REC->__probe_ip, REC->pathname
Instead of using "__get_str(pathname)" it referenced it directly.
Link: http://lkml.kernel.org/r/20200124100742.4050c15e@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 88903c4643 ("tracing/probe: Add ustring type for user-space string")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As warnings can trigger panics, especially when "panic_on_warn" is set,
memory failure warnings can cause panics and fail fuzz testers that are
stressing memory.
Create a MEM_FAIL() macro to use instead of WARN() in the tracing code
(perhaps this should be a kernel wide macro?), and use that for memory
failure issues. This should stop failing fuzz tests due to warnings.
Link: https://lore.kernel.org/r/CACT4Y+ZP-7np20GVRu3p+eZys9GPtbu+JpfV+HtsufAzvTgJrg@mail.gmail.com
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The trace_array_get_by_name() creates a ftrace instance and
trace_array_put() is used to remove the reference. Even though the
trace_array_get_by_name() creates the instance, it also adds a reference
count to it, that prevents user space from removing it.
As the bootconfig just creates the instance on boot up, it should still be
used where it can be deleted by user space after boot. A trace_array_put()
is required to let that happen.
Also, change the documentation on trace_array_get_by_name() to make this not
be so confusing.
Link: https://lore.kernel.org/r/20200124205927.76128804@rorschach.local.home
Fixes: 4f712a4d04 ("tracing/boot: Add instance node support")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
We checked "iter->trace" earlier so there is no need to check here.
Link: http://lkml.kernel.org/r/20141122183012.GB6994@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
I noticed when trying to use the trace-cmd python interface that reading the raw
buffer wasn't working for kernel_stack events. This is because it uses a
stubbed version of __dynamic_array that doesn't do the __data_loc trick and
encode the length of the array into the field. Instead it just shows up as a
size of 0. So change this to __array and set the len to FTRACE_STACK_ENTRIES
since this is what we actually do in practice and matches how user_stack_trace
works.
Link: http://lkml.kernel.org/r/1411589652-1318-1-git-send-email-jbacik@fb.com
Signed-off-by: Josef Bacik <jbacik@fb.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracing_stat_init() was always returning '0', even on the error paths. It
now returns -ENODEV if tracing_init_dentry() fails or -ENOMEM if it fails
to created the 'trace_stat' debugfs directory.
Link: http://lkml.kernel.org/r/1410299381-20108-1-git-send-email-luis.henriques@canonical.com
Fixes: ed6f1c996b ("tracing: Check return value of tracing_init_dentry()")
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Looking through old emails in my INBOX, I came across a patch from Luis
Henriques that attempted to fix a race of two stat tracers registering the
same stat trace (extremely unlikely, as this is done in the kernel, and
probably doesn't even exist). The submitted patch wasn't quite right as it
needed to deal with clean up a bit better (if two stat tracers were the
same, it would have the same files).
But to make the code cleaner, all we needed to do is to keep the
all_stat_sessions_mutex held for most of the registering function.
Link: http://lkml.kernel.org/r/1410299375-20068-1-git-send-email-luis.henriques@canonical.com
Fixes: 002bb86d8d ("tracing/ftrace: separate events tracing and stats tracing engine")
Reported-by: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Alexei Starovoitov says:
====================
pull-request: bpf-next 2020-01-22
The following pull-request contains BPF updates for your *net-next* tree.
We've added 92 non-merge commits during the last 16 day(s) which contain
a total of 320 files changed, 7532 insertions(+), 1448 deletions(-).
The main changes are:
1) function by function verification and program extensions from Alexei.
2) massive cleanup of selftests/bpf from Toke and Andrii.
3) batched bpf map operations from Brian and Yonghong.
4) tcp congestion control in bpf from Martin.
5) bulking for non-map xdp_redirect form Toke.
6) bpf_send_signal_thread helper from Yonghong.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 99c9a923e9 ("tracing/uprobe: Fix double perf_event
linking on multiprobe uprobe") moved trace_uprobe_filter on
trace_probe_event. However, since it introduced a flexible
data structure with char array and type casting, the
alignment of trace_uprobe_filter can be broken.
This changes the type of the array to trace_uprobe_filter
data strucure to fix it.
Link: http://lore.kernel.org/r/20200120124022.GA14897@hirez.programming.kicks-ass.net
Link: http://lkml.kernel.org/r/157966340499.5107.10978352478952144902.stgit@devnote2
Fixes: 99c9a923e9 ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This limitation are never lunched from introduce commit 970988e19e
("tracing/kprobe: Add kprobe_event= boot parameter")
Could we remove it if no intention to implement it?
Link: http://lkml.kernel.org/r/1579586075-45132-1-git-send-email-alex.shi@linux.alibaba.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If we exit due to a bad input to trace_printk() (highly unlikely), then the
buffer variable will not be initialized when we unnest the ring buffer.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When trace_clock option is not set and unstable clcok detected,
tracing_set_default_clock() sets trace_clock(ThinkPad A285 is one of
case). In that case, if lockdown is in effect, null pointer
dereference error happens in ring_buffer_set_clock().
Link: http://lkml.kernel.org/r/20200116131236.3866925-1-masami256@gmail.com
Cc: stable@vger.kernel.org
Fixes: 17911ff38a ("tracing: Add locked_down checks to the open calls of files created for tracefs")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1788488
Signed-off-by: Masami Ichikawa <masami256@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
While working on a tool to convert SQL syntex into the histogram language of
the kernel, I discovered the following bug:
# echo 'first u64 start_time u64 end_time pid_t pid u64 delta' >> synthetic_events
# echo 'hist:keys=pid:start=common_timestamp' > events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:delta=common_timestamp-$start,start2=$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
Would not display any histograms in the sched_switch histogram side.
But if I were to swap the location of
"delta=common_timestamp-$start" with "start2=$start"
Such that the last line had:
# echo 'hist:keys=next_pid:start2=$start,delta=common_timestamp-$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
The histogram works as expected.
What I found out is that the expressions clear out the value once it is
resolved. As the variables are resolved in the order listed, when
processing:
delta=common_timestamp-$start
The $start is cleared. When it gets to "start2=$start", it errors out with
"unresolved symbol" (which is silent as this happens at the location of the
trace), and the histogram is dropped.
When processing the histogram for variable references, instead of adding a
new reference for a variable used twice, use the same reference. That way,
not only is it more efficient, but the order will no longer matter in
processing of the variables.
From Tom Zanussi:
"Just to clarify some more about what the problem was is that without
your patch, we would have two separate references to the same variable,
and during resolve_var_refs(), they'd both want to be resolved
separately, so in this case, since the first reference to start wasn't
part of an expression, it wouldn't get the read-once flag set, so would
be read normally, and then the second reference would do the read-once
read and also be read but using read-once. So everything worked and
you didn't see a problem:
from: start2=$start,delta=common_timestamp-$start
In the second case, when you switched them around, the first reference
would be resolved by doing the read-once, and following that the second
reference would try to resolve and see that the variable had already
been read, so failed as unset, which caused it to short-circuit out and
not do the trigger action to generate the synthetic event:
to: delta=common_timestamp-$start,start2=$start
With your patch, we only have the single resolution which happens
correctly the one time it's resolved, so this can't happen."
Link: https://lore.kernel.org/r/20200116154216.58ca08eb@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 067fe038e7 ("tracing: Add variable reference handling to hist triggers")
Reviewed-by: Tom Zanuss <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If syscall_enter_define_fields() is called on a system call with no
arguments, the return code variable "ret" will never get initialized.
Initialize it to zero.
Fixes: 04ae87a520 ("ftrace: Rework event_create_dir()")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/0FA8C6E3-D9F5-416D-A1B0-5E4CD583A101@lca.pw
trace_printk() is used to debug the kernel which includes the tracing
infrastructure. But because it writes to the ring buffer, and so does much
of the tracing infrastructure, the ring buffer's recursive detection will
drop writes to the ring buffer that is in the same context as the current
write is happening (it allows interrupts to write when normal context is
writing, but wont let normal context write while normal context is writing).
This can cause confusion and think that the code is where the trace_printk()
exists is not hit. To solve this, up the recursive nesting of the ring
buffer when trace_printk() is called before it writes to the buffer itself.
Note, this does make it dangerous to use trace_printk() in the ring buffer
code itself, because this basically disables the recursion protection of
trace_printk() buffer writes. But as trace_printk() is only used for
debugging, and if this does occur, the developer will see the cause real
quick (recursive blowing up of the stack). Thus the developer can deal with
that. But having trace_printk() silently ignored is a much bigger problem,
and disabling recursive protection is a small price to pay to fix it.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Commit 8b401f9ed2 ("bpf: implement bpf_send_signal() helper")
added helper bpf_send_signal() which permits bpf program to
send a signal to the current process. The signal may be
delivered to any threads in the process.
We found a use case where sending the signal to the current
thread is more preferable.
- A bpf program will collect the stack trace and then
send signal to the user application.
- The user application will add some thread specific
information to the just collected stack trace for
later analysis.
If bpf_send_signal() is used, user application will need
to check whether the thread receiving the signal matches
the thread collecting the stack by checking thread id.
If not, it will need to send signal to another thread
through pthread_kill().
This patch proposed a new helper bpf_send_signal_thread(),
which sends the signal to the thread corresponding to
the current kernel task. This way, user space is guaranteed that
bpf_program execution context and user space signal handling
context are the same thread.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115035002.602336-1-yhs@fb.com
With CONFIG_PROVE_RCU_LIST, I had many suspicious RCU warnings
when I ran ftracetest trigger testcases.
-----
# dmesg -c > /dev/null
# ./ftracetest test.d/trigger
...
# dmesg | grep "RCU-list traversed" | cut -f 2 -d ] | cut -f 2 -d " "
kernel/trace/trace_events_hist.c:6070
kernel/trace/trace_events_hist.c:1760
kernel/trace/trace_events_hist.c:5911
kernel/trace/trace_events_trigger.c:504
kernel/trace/trace_events_hist.c:1810
kernel/trace/trace_events_hist.c:3158
kernel/trace/trace_events_hist.c:3105
kernel/trace/trace_events_hist.c:5518
kernel/trace/trace_events_hist.c:5998
kernel/trace/trace_events_hist.c:6019
kernel/trace/trace_events_hist.c:6044
kernel/trace/trace_events_trigger.c:1500
kernel/trace/trace_events_trigger.c:1540
kernel/trace/trace_events_trigger.c:539
kernel/trace/trace_events_trigger.c:584
-----
I investigated those warnings and found that the RCU-list
traversals in event trigger and hist didn't need to use
RCU version because those were called only under event_mutex.
I also checked other RCU-list traversals related to event
trigger list, and found that most of them were called from
event_hist_trigger_func() or hist_unregister_trigger() or
register/unregister functions except for a few cases.
Replace these unneeded RCU-list traversals with normal list
traversal macro and lockdep_assert_held() to check the
event_mutex is held.
Link: http://lkml.kernel.org/r/157680910305.11685.15110237954275915782.stgit@devnote2
Cc: stable@vger.kernel.org
Fixes: 30350d65ac ("tracing: Add variable support to hist triggers")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Also fixes a couple of typos
Link: http://lkml.kernel.org/r/1401992525-10417-1-git-send-email-fabf@skynet.be
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
[ Found this deep in the abyss of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fix double perf_event linking to trace_uprobe_filter on
multiple uprobe event by moving trace_uprobe_filter under
trace_probe_event.
In uprobe perf event, trace_uprobe_filter data structure is
managing target mm filters (in perf_event) related to each
uprobe event.
Since commit 60d53e2c3b ("tracing/probe: Split trace_event
related data from trace_probe") left the trace_uprobe_filter
data structure in trace_uprobe, if a trace_probe_event has
multiple trace_uprobe (multi-probe event), a perf_event is
added to different trace_uprobe_filter on each trace_uprobe.
This leads a linked list corruption.
To fix this issue, move trace_uprobe_filter to trace_probe_event
and link it once on each event instead of each probe.
Link: http://lkml.kernel.org/r/157862073931.1800.3800576241181489174.stgit@devnote2
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S . Miller" <davem@davemloft.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: =?utf-8?q?Toke_H=C3=B8iland-J?= =?utf-8?b?w7hyZ2Vuc2Vu?= <thoiland@redhat.com>
Cc: Jean-Tsung Hsiao <jhsiao@redhat.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 60d53e2c3b ("tracing/probe: Split trace_event related data from trace_probe")
Link: https://lkml.kernel.org/r/20200108171611.GA8472@kernel.org
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
With CONFIG_PROVE_RCU_LIST, I had many suspicious RCU warnings
when I ran ftracetest trigger testcases.
-----
# dmesg -c > /dev/null
# ./ftracetest test.d/trigger
...
# dmesg | grep "RCU-list traversed" | cut -f 2 -d ] | cut -f 2 -d " "
kernel/trace/trace_events_hist.c:6070
kernel/trace/trace_events_hist.c:1760
kernel/trace/trace_events_hist.c:5911
kernel/trace/trace_events_trigger.c:504
kernel/trace/trace_events_hist.c:1810
kernel/trace/trace_events_hist.c:3158
kernel/trace/trace_events_hist.c:3105
kernel/trace/trace_events_hist.c:5518
kernel/trace/trace_events_hist.c:5998
kernel/trace/trace_events_hist.c:6019
kernel/trace/trace_events_hist.c:6044
kernel/trace/trace_events_trigger.c:1500
kernel/trace/trace_events_trigger.c:1540
kernel/trace/trace_events_trigger.c:539
kernel/trace/trace_events_trigger.c:584
-----
I investigated those warnings and found that the RCU-list
traversals in event trigger and hist didn't need to use
RCU version because those were called only under event_mutex.
I also checked other RCU-list traversals related to event
trigger list, and found that most of them were called from
event_hist_trigger_func() or hist_unregister_trigger() or
register/unregister functions except for a few cases.
Replace these unneeded RCU-list traversals with normal list
traversal macro and lockdep_assert_held() to check the
event_mutex is held.
Link: http://lkml.kernel.org/r/157680910305.11685.15110237954275915782.stgit@devnote2
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add below function-tracer filter options to boot-time tracing.
- ftrace.[instance.INSTANCE.]ftrace.filters
This will take an array of tracing function filter rules
- ftrace.[instance.INSTANCE.]ftrace.notraces
This will take an array of NON-tracing function filter rules
Link: http://lkml.kernel.org/r/157867244841.17873.10933616628243103561.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add ftrace.cpumask option support to boot-time tracing.
This sets cpumask for each instance.
- ftrace.[instance.INSTANCE.]cpumask = CPUMASK;
Set the trace cpumask. Note that the CPUMASK should be a string
which <tracefs>/tracing_cpumask can accepts.
Link: http://lkml.kernel.org/r/157867243625.17873.13613922641273149372.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add instance node support to boot-time tracing. User can set
some options and event nodes under instance node.
- ftrace.instance.INSTANCE[...]
Add new INSTANCE instance. Some options and event nodes
are acceptable for instance node.
Link: http://lkml.kernel.org/r/157867242413.17873.9814204526141500278.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add synthetic event node support to boot time tracing.
The synthetic event is a kind of event node, but the group
name is "synthetic".
- ftrace.event.synthetic.EVENT.fields = FIELD[, FIELD2...]
Defines new synthetic event with FIELDs. Each field should be
"type varname".
The synthetic node requires "fields" string arraies, which defines
the fields as same as tracing/synth_events interface.
Link: http://lkml.kernel.org/r/157867241236.17873.12411615143321557709.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add kprobe event support on event node to boot-time tracing.
If the group name of event is "kprobes", the boot-time tracing
defines new probe event according to "probes" values.
- ftrace.event.kprobes.EVENT.probes = PROBE[, PROBE2...]
Defines new kprobe event based on PROBEs. It is able to define
multiple probes on one event, but those must have same type of
arguments.
For example,
ftrace.events.kprobes.myevent {
probes = "vfs_read $arg1 $arg2";
enable;
}
This will add kprobes:myevent on vfs_read with the 1st and the 2nd
arguments.
Link: http://lkml.kernel.org/r/157867240104.17873.9712052065426433111.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add per-event settings for boottime tracing. User can set filter,
actions and enable on each event on boot. The event entries are
under ftrace.event.GROUP.EVENT node (note that the option key
includes event's group name and event name.) This supports below
configs.
- ftrace.event.GROUP.EVENT.enable
Enables GROUP:EVENT tracing.
- ftrace.event.GROUP.EVENT.filter = FILTER
Set FILTER rule to the GROUP:EVENT.
- ftrace.event.GROUP.EVENT.actions = ACTION[, ACTION2...]
Set ACTIONs to the GROUP:EVENT.
For example,
ftrace.event.sched.sched_process_exec {
filter = "pid < 128"
enable
}
this will enable tracing "sched:sched_process_exec" event
with "pid < 128" filter.
Link: http://lkml.kernel.org/r/157867238942.17873.11177628789184546198.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Setup tracing options via extra boot config in addition to kernel
command line.
This adds following commands support. These are applied to
the global trace instance.
- ftrace.options = OPT1[,OPT2...]
Enable given ftrace options.
- ftrace.trace_clock = CLOCK
Set given CLOCK to ftrace's trace_clock.
- ftrace.buffer_size = SIZE
Configure ftrace buffer size to SIZE. You can use "KB" or "MB"
for that SIZE.
- ftrace.events = EVENT[, EVENT2...]
Enable given events on boot. You can use a wild card in EVENT.
- ftrace.tracer = TRACER
Set TRACER to current tracer on boot. (e.g. function)
Note that this is NOT replacing the kernel parameters, because
this boot config based setting is later than that. If you want to
trace earlier boot events, you still need kernel parameters.
Link: http://lkml.kernel.org/r/157867237723.17873.17494943526320587488.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Make the synthetic event accepts a different type field to record.
However, the size and signed flag must be same.
Link: http://lkml.kernel.org/r/157867235358.17873.61732996461602171.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Register kprobe event to dynevent in subsys_initcall level.
This will allow kernel to register new kprobe events in
fs_initcall level via trace_run_command.
Link: http://lkml.kernel.org/r/157867234213.17873.18039000024374948737.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since kprobe-events use event_trigger_unlock_commit_regs() directly,
that events doesn't show up in printk buffer if "tp_printk" is set.
Use trace_event_buffer_commit() in kprobe events so that it can
invoke output_printk() as same as other trace events.
Link: http://lkml.kernel.org/r/157867233085.17873.5210928676787339604.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[ Adjusted data var declaration placement in __kretprobe_trace_func() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Apply soft-disabled and the filter rule of the trace events to
the printk output of tracepoints (a.k.a. tp_printk kernel parameter)
as same as trace buffer output.
Link: http://lkml.kernel.org/r/157867231876.17873.15825819592284704068.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As there's two struct ring_buffers in the kernel, it causes some confusion.
The other one being the perf ring buffer. It was agreed upon that as neither
of the ring buffers are generic enough to be used globally, they should be
renamed as:
perf's ring_buffer -> perf_buffer
ftrace's ring_buffer -> trace_buffer
This implements the changes to the ring buffer that ftrace uses.
Link: https://lore.kernel.org/r/20191213140531.116b3200@gandalf.local.home
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As we are working to remove the generic "ring_buffer" name that is used by
both tracing and perf, the ring_buffer name for tracing will be renamed to
trace_buffer, and perf's ring buffer will be renamed to perf_buffer.
As there already exists a trace_buffer that is used by the trace_arrays, it
needs to be first renamed to array_buffer.
Link: https://lore.kernel.org/r/20191213153553.GE20583@krava
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In the function, if register_trace_sched_migrate_task() returns error,
sched_switch/sched_wakeup_new/sched_wakeup won't unregister. That is
why fail_deprobe_sched_switch was added.
Link: http://lkml.kernel.org/r/20191231133530.2794-1-pilgrimtao@gmail.com
Cc: stable@vger.kernel.org
Fixes: 478142c39c ("tracing: do not grab lock in wakeup latency function tracing")
Signed-off-by: Kaitao Cheng <pilgrimtao@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The ftrace_profile->counter is unsigned long and
do_div truncates it to 32 bits, which means it can test
non-zero and be truncated to zero for division.
Fix this issue by using div64_ul() instead.
Link: http://lkml.kernel.org/r/20200103030248.14516-1-wenyang@linux.alibaba.com
Cc: stable@vger.kernel.org
Fixes: e330b3bcd8 ("tracing: Show sample std dev in function profiling")
Fixes: 34886c8bc5 ("tracing: add average time in function to function profiler")
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
On some archs with some configurations, MCOUNT_INSN_SIZE is not defined, and
this makes the stack tracer fail to compile. Just define it to zero in this
case.
Link: https://lore.kernel.org/r/202001020219.zvE3vsty%lkp@intel.com
Cc: stable@vger.kernel.org
Fixes: 4df297129f ("tracing: Remove most or all of stack tracer stack size from stack_max_size")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In order to handle direct calls along side of function graph tracer, a check
is made to see if the address being traced by the function graph tracer is a
direct call or not. To get the address used by direct callers, the return
address is subtracted by MCOUNT_INSN_SIZE.
For some archs with certain configurations, MCOUNT_INSN_SIZE is undefined
here. But these should not be using direct calls anyway. Just define
MCOUNT_INSN_SIZE to zero in this case.
Link: https://lore.kernel.org/r/202001020219.zvE3vsty%lkp@intel.com
Reported-by: kbuild test robot <lkp@intel.com>
Fixes: ff205766db ("ftrace: Fix function_graph tracer interaction with BPF trampoline")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
gcc produces a variable may be uninitialized warning for "val" in
parse_entry(). This is really a false positive, but the code is subtle
enough to just initialize val to zero and it's not a fast path to worry
about it.
Marked for stable to remove the warning in the stable trees as well.
Cc: stable@vger.kernel.org
Fixes: 6c3edaf9fd ("tracing: Introduce trace event injection")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
At least on PA-RISC and s390 synthetic histogram triggers are failing
selftests because trace_event_raw_event_synth() always writes a 64 bit
values, but the reader expects a field->size sized value. On little endian
machines this doesn't hurt, but on big endian this makes the reader always
read zero values.
Link: http://lore.kernel.org/linux-trace-devel/20191218074427.96184-4-svens@linux.ibm.com
Cc: stable@vger.kernel.org
Fixes: 4b147936fa ("tracing: Add support for 'synthetic' events")
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Task T2 Task T3
trace_options_core_write() subsystem_open()
mutex_lock(trace_types_lock) mutex_lock(event_mutex)
set_tracer_flag()
trace_event_enable_tgid_record() mutex_lock(trace_types_lock)
mutex_lock(event_mutex)
This gives a circular dependency deadlock between trace_types_lock and
event_mutex. To fix this invert the usage of trace_types_lock and
event_mutex in trace_options_core_write(). This keeps the sequence of
lock usage consistent.
Link: http://lkml.kernel.org/r/0101016eef175e38-8ca71caf-a4eb-480d-a1e6-6f0bbc015495-000000@us-west-2.amazonses.com
Cc: stable@vger.kernel.org
Fixes: d914ba37d7 ("tracing: Add support for recording tgid of tasks")
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The compare functions of the histogram code would be specific for the size
of the value being compared (byte, short, int, long long). It would
reference the value from the array via the type of the compare, but the
value was stored in a 64 bit number. This is fine for little endian
machines, but for big endian machines, it would end up comparing zeros or
all ones (depending on the sign) for anything but 64 bit numbers.
To fix this, first derference the value as a u64 then convert it to the type
being compared.
Link: http://lkml.kernel.org/r/20191211103557.7bed6928@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 08d43a5fa0 ("tracing: Add lock-free tracing_map")
Acked-by: Tom Zanussi <zanussi@kernel.org>
Reported-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
- Removal of code I accidentally applied when doing a minor fix up
to a patch, and then using "git commit -a --amend", which pulled
in some other changes I was playing with.
- Remove an used variable in trace_events_inject code
- Fix to function graph tracer when it traces a ftrace direct function.
It will now ignore tracing a function that has a ftrace direct
tramploine attached. This is needed for eBPF to use the ftrace direct
code.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXfD/thQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qoo2AP4j7ONw7BTmMyo+GdYqPPntBeDnClHK
vfMKrgK1j5BxYgEA7LgkwuUT9bcyLjfJVcyfeW67rB2PtmovKTWnKihFOwI=
=DZ6N
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
- Remove code I accidentally applied when doing a minor fix up to a
patch, and then using "git commit -a --amend", which pulled in some
other changes I was playing with.
- Remove an used variable in trace_events_inject code
- Fix function graph tracer when it traces a ftrace direct function.
It will now ignore tracing a function that has a ftrace direct
tramploine attached. This is needed for eBPF to use the ftrace direct
code.
* tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Fix function_graph tracer interaction with BPF trampoline
tracing: remove set but not used variable 'buffer'
module: Remove accidental change of module_enable_x()
Depending on type of BPF programs served by BPF trampoline it can call original
function. In such case the trampoline will skip one stack frame while
returning. That will confuse function_graph tracer and will cause crashes with
bad RIP. Teach graph tracer to skip functions that have BPF trampoline attached.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
kernel/trace/trace_events_inject.c: In function trace_inject_entry:
kernel/trace/trace_events_inject.c:20:22: warning: variable buffer set but not used [-Wunused-but-set-variable]
It is never used, so remove it.
Link: http://lkml.kernel.org/r/20191207034409.25668-1-yuehaibing@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20191206092503.303d6a57@canb.auug.org.au
Cc: Linux Next Mailing List <linux-next@vger.kernel.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Fixes:
- Missing __print_hex_dump undef for processing new function in trace events
- Stop WARN_ON messages when lockdown disables tracing on boot up
Enhancement:
- Debug option to inject trace events from userspace (for rasdaemon)
The enhancement has its own config option and is non invasive. It's been
discussed for sever months and should have been added to my original
push, but I never pulled it into my queue.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXehlhRQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qlGgAQCszcDuNyVllj0VwWi4i+0FAQcI12Ad
W0NGZm0wObGExwD8CDR/CdHq9ulizFQjJfopG6b5Uc3Z4NNJ+QGnMxzBuwo=
=k31z
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull more tracing updates from Steven Rostedt:
"Two fixes and one patch that was missed:
Fixes:
- Missing __print_hex_dump undef for processing new function in trace
events
- Stop WARN_ON messages when lockdown disables tracing on boot up
Enhancement:
- Debug option to inject trace events from userspace (for rasdaemon)"
The enhancement has its own config option and is non invasive. It's been
discussed for sever months and should have been added to my original
push, but I never pulled it into my queue.
* tag 'trace-v5.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Do not create directories if lockdown is in affect
tracing: Introduce trace event injection
tracing: Fix __print_hex_dump scope
If lockdown is disabling tracing on boot up, it prevents the tracing files
from even bering created. But when that happens, there's several places that
will give a warning that the files were not created as that is usually a
sign of a bug.
Add in strategic locations where a check is made to see if tracing is
disabled by lockdown, and if it is, do not go further, and fail silently
(but print that tracing is disabled by lockdown, without doing a WARN_ON()).
Cc: Matthew Garrett <mjg59@google.com>
Fixes: 17911ff38a ("tracing: Add locked_down checks to the open calls of files created for tracefs")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull irq updates from Ingo Molnar:
"Most of the IRQ subsystem changes in this cycle were irq-chip driver
updates:
- Qualcomm PDC wakeup interrupt support
- Layerscape external IRQ support
- Broadcom bcm7038 PM and wakeup support
- Ingenic driver cleanup and modernization
- GICv3 ITS preparation for GICv4.1 updates
- GICv4 fixes
There's also the series from Frederic Weisbecker that fixes memory
ordering bugs for the irq-work logic, whose primary fix is to turn
work->irq_work.flags into an atomic variable and then convert the
complex (and buggy) atomic_cmpxchg() loop in irq_work_claim() into a
much simpler atomic_fetch_or() call.
There are also various smaller cleanups"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
pinctrl/sdm845: Add PDC wakeup interrupt map for GPIOs
pinctrl/msm: Setup GPIO chip in hierarchy
irqchip/qcom-pdc: Add irqchip set/get state calls
irqchip/qcom-pdc: Add irqdomain for wakeup capable GPIOs
irqchip/qcom-pdc: Do not toggle IRQ_ENABLE during mask/unmask
irqchip/qcom-pdc: Update max PDC interrupts
of/irq: Document properties for wakeup interrupt parent
genirq: Introduce irq_chip_get/set_parent_state calls
irqdomain: Add bus token DOMAIN_BUS_WAKEUP
genirq: Fix function documentation of __irq_alloc_descs()
irq_work: Fix IRQ_WORK_BUSY bit clearing
irqchip/ti-sci-inta: Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...))
irq_work: Slightly simplify IRQ_WORK_PENDING clearing
irq_work: Fix irq_work_claim() memory ordering
irq_work: Convert flags to atomic_t
irqchip: Ingenic: Add process for more than one irq at the same time.
irqchip: ingenic: Alloc generic chips from IRQ domain
irqchip: ingenic: Get virq number from IRQ domain
irqchip: ingenic: Error out if IRQ domain creation failed
irqchip: ingenic: Drop redundant irq_suspend / irq_resume functions
...
We have been trying to use rasdaemon to monitor hardware errors like
correctable memory errors. rasdaemon uses trace events to monitor
various hardware errors. In order to test it, we have to inject some
hardware errors, unfortunately not all of them provide error
injections. MCE does provide a way to inject MCE errors, but errors
like PCI error and devlink error don't, it is not easy to add error
injection to each of them. Instead, it is relatively easier to just
allow users to inject trace events in a generic way so that all trace
events can be injected.
This patch introduces trace event injection, where a new 'inject' is
added to each tracepoint directory. Users could write into this file
with key=value pairs to specify the value of each fields of the trace
event, all unspecified fields are set to zero values by default.
For example, for the net/net_dev_queue tracepoint, we can inject:
INJECT=/sys/kernel/debug/tracing/events/net/net_dev_queue/inject
echo "" > $INJECT
echo "name='test'" > $INJECT
echo "name='test' len=1024" > $INJECT
cat /sys/kernel/debug/tracing/trace
...
<...>-614 [000] .... 36.571483: net_dev_queue: dev= skbaddr=00000000fbf338c2 len=0
<...>-614 [001] .... 136.588252: net_dev_queue: dev=test skbaddr=00000000fbf338c2 len=0
<...>-614 [001] .N.. 208.431878: net_dev_queue: dev=test skbaddr=00000000fbf338c2 len=1024
Triggers could be triggered as usual too:
echo "stacktrace if len == 1025" > /sys/kernel/debug/tracing/events/net/net_dev_queue/trigger
echo "len=1025" > $INJECT
cat /sys/kernel/debug/tracing/trace
...
bash-614 [000] .... 36.571483: net_dev_queue: dev= skbaddr=00000000fbf338c2 len=0
bash-614 [001] .... 136.588252: net_dev_queue: dev=test skbaddr=00000000fbf338c2 len=0
bash-614 [001] .N.. 208.431878: net_dev_queue: dev=test skbaddr=00000000fbf338c2 len=1024
bash-614 [001] .N.1 284.236349: <stack trace>
=> event_inject_write
=> vfs_write
=> ksys_write
=> do_syscall_64
=> entry_SYSCALL_64_after_hwframe
The only thing that can't be injected is string pointers as they
require constant string pointers, this can't be done at run time.
Link: http://lkml.kernel.org/r/20191130045218.18979-1-xiyou.wangcong@gmail.com
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
- PERAMAENT flag to ftrace_ops when attaching a callback to a function
As /proc/sys/kernel/ftrace_enabled when set to zero will disable all
attached callbacks in ftrace, this has a detrimental impact on live
kernel tracing, as it disables all that it patched. If a ftrace_ops
is registered to ftrace with the PERMANENT flag set, it will prevent
ftrace_enabled from being disabled, and if ftrace_enabled is already
disabled, it will prevent a ftrace_ops with PREMANENT flag set from
being registered.
- New register_ftrace_direct(). As eBPF would like to register its own
trampolines to be called by the ftrace nop locations directly,
without going through the ftrace trampoline, this function has been
added. This allows for eBPF trampolines to live along side of
ftrace, perf, kprobe and live patching. It also utilizes the ftrace
enabled_functions file that keeps track of functions that have been
modified in the kernel, to allow for security auditing.
- Allow for kernel internal use of ftrace instances. Subsystems in
the kernel can now create and destroy their own tracing instances
which allows them to have their own tracing buffer, and be able
to record events without worrying about other users from writing over
their data.
- New seq_buf_hex_dump() that lets users use the hex_dump() in their
seq_buf usage.
- Notifications now added to tracing_max_latency to allow user space
to know when a new max latency is hit by one of the latency tracers.
- Wider spread use of generic compare operations for use of bsearch and
friends.
- More synthetic event fields may be defined (32 up from 16)
- Use of xarray for architectures with sparse system calls, for the
system call trace events.
This along with small clean ups and fixes.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXdwv4BQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qnB5AP91vsdHQjwE1+/UWG/cO+qFtKvn2QJK
QmBRIJNH/s+1TAD/fAOhgw+ojSK3o/qc+NpvPTEW9AEwcJL1wacJUn+XbQc=
=ztql
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"New tracing features:
- New PERMANENT flag to ftrace_ops when attaching a callback to a
function.
As /proc/sys/kernel/ftrace_enabled when set to zero will disable
all attached callbacks in ftrace, this has a detrimental impact on
live kernel tracing, as it disables all that it patched. If a
ftrace_ops is registered to ftrace with the PERMANENT flag set, it
will prevent ftrace_enabled from being disabled, and if
ftrace_enabled is already disabled, it will prevent a ftrace_ops
with PREMANENT flag set from being registered.
- New register_ftrace_direct().
As eBPF would like to register its own trampolines to be called by
the ftrace nop locations directly, without going through the ftrace
trampoline, this function has been added. This allows for eBPF
trampolines to live along side of ftrace, perf, kprobe and live
patching. It also utilizes the ftrace enabled_functions file that
keeps track of functions that have been modified in the kernel, to
allow for security auditing.
- Allow for kernel internal use of ftrace instances.
Subsystems in the kernel can now create and destroy their own
tracing instances which allows them to have their own tracing
buffer, and be able to record events without worrying about other
users from writing over their data.
- New seq_buf_hex_dump() that lets users use the hex_dump() in their
seq_buf usage.
- Notifications now added to tracing_max_latency to allow user space
to know when a new max latency is hit by one of the latency
tracers.
- Wider spread use of generic compare operations for use of bsearch
and friends.
- More synthetic event fields may be defined (32 up from 16)
- Use of xarray for architectures with sparse system calls, for the
system call trace events.
This along with small clean ups and fixes"
* tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (51 commits)
tracing: Enable syscall optimization for MIPS
tracing: Use xarray for syscall trace events
tracing: Sample module to demonstrate kernel access to Ftrace instances.
tracing: Adding new functions for kernel access to Ftrace instances
tracing: Fix Kconfig indentation
ring-buffer: Fix typos in function ring_buffer_producer
ftrace: Use BIT() macro
ftrace: Return ENOTSUPP when DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not configured
ftrace: Rename ftrace_graph_stub to ftrace_stub_graph
ftrace: Add a helper function to modify_ftrace_direct() to allow arch optimization
ftrace: Add helper find_direct_entry() to consolidate code
ftrace: Add another check for match in register_ftrace_direct()
ftrace: Fix accounting bug with direct->count in register_ftrace_direct()
ftrace/selftests: Fix spelling mistake "wakeing" -> "waking"
tracing: Increase SYNTH_FIELDS_MAX for synthetic_events
ftrace/samples: Add a sample module that implements modify_ftrace_direct()
ftrace: Add modify_ftrace_direct()
tracing: Add missing "inline" in stub function of latency_fsnotify()
tracing: Remove stray tab in TRACE_EVAL_MAP_FILE's help text
tracing: Use seq_buf_hex_dump() to dump buffers
...
Here is the "big" set of driver core patches for 5.5-rc1
There's a few minor cleanups and fixes in here, but the majority of the
patches in here fall into two buckets:
- debugfs api cleanups and fixes
- driver core device link support for boot dependancy issues
The debugfs api cleanups are working to slowly refactor the debugfs apis
so that it is even harder to use incorrectly. That work has been
happening for the past few kernel releases and will continue over time,
it's a long-term project/goal
The driver core device link support missed 5.4 by just a bit, so it's
been sitting and baking for many months now. It's from Saravana Kannan
to help resolve the problems that DT-based systems have at boot time
with dependancy graphs and kernel modules. Turns out that no one has
actually tried to build a generic arm64 kernel with loads of modules and
have it "just work" for a variety of platforms (like a distro kernel)
The big problem turned out to be a lack of depandancy information
between different areas of DT entries, and the work here resolves that
problem and now allows devices to boot properly, and quicker than a
monolith kernel.
All of these patches have been in linux-next for a long time with no
reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXd6m6Q8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+yntJQCcCqg6RQ7LTdHuZv1ETeefXlsfk00An1Jtean6
42bWGx52bGFvAcpjWy8R
=P7hq
-----END PGP SIGNATURE-----
Merge tag 'driver-core-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the "big" set of driver core patches for 5.5-rc1
There's a few minor cleanups and fixes in here, but the majority of
the patches in here fall into two buckets:
- debugfs api cleanups and fixes
- driver core device link support for boot dependancy issues
The debugfs api cleanups are working to slowly refactor the debugfs
apis so that it is even harder to use incorrectly. That work has been
happening for the past few kernel releases and will continue over
time, it's a long-term project/goal
The driver core device link support missed 5.4 by just a bit, so it's
been sitting and baking for many months now. It's from Saravana Kannan
to help resolve the problems that DT-based systems have at boot time
with dependancy graphs and kernel modules. Turns out that no one has
actually tried to build a generic arm64 kernel with loads of modules
and have it "just work" for a variety of platforms (like a distro
kernel). The big problem turned out to be a lack of dependency
information between different areas of DT entries, and the work here
resolves that problem and now allows devices to boot properly, and
quicker than a monolith kernel.
All of these patches have been in linux-next for a long time with no
reported issues"
* tag 'driver-core-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (68 commits)
tracing: Remove unnecessary DEBUG_FS dependency
of: property: Add device link support for interrupt-parent, dmas and -gpio(s)
debugfs: Fix !DEBUG_FS debugfs_create_automount
of: property: Add device link support for "iommu-map"
of: property: Fix the semantics of of_is_ancestor_of()
i2c: of: Populate fwnode in of_i2c_get_board_info()
drivers: base: Fix Kconfig indentation
firmware_loader: Fix labels with comma for builtin firmware
driver core: Allow device link operations inside sync_state()
driver core: platform: Declare ret variable only once
cpu-topology: declare parse_acpi_topology in <linux/arch_topology.h>
crypto: hisilicon: no need to check return value of debugfs_create functions
driver core: platform: use the correct callback type for bus_find_device
firmware_class: make firmware caching configurable
driver core: Clarify documentation for fwnode_operations.add_links()
mailbox: tegra: Fix superfluous IRQ error message
net: caif: Fix debugfs on 64-bit platforms
mac80211: Use debugfs_create_xul() helper
media: c8sectpfe: no need to check return value of debugfs_create functions
of: property: Add device link support for iommus, mboxes and io-channels
...
Rework event_create_dir() to use an array of static data instead of
function pointers where possible.
The problem is that it would call the function pointer on module load
before parse_args(), possibly even before jump_labels were initialized.
Luckily the generated functions don't use jump_labels but it still seems
fragile. It also gets in the way of changing when we make the module map
executable.
The generated function are basically calling trace_define_field() with a
bunch of static arguments. So instead of a function, capture these
arguments in a static array, avoiding the function call.
Now there are a number of cases where the fields are dynamic (syscall
arguments, kprobes and uprobes), in which case a static array does not
work, for these we preserve the function call. Luckily all these cases
are not related to modules and so we can retain the function call for
them.
Also fix up all broken tracepoint definitions that now generate a
compile error.
Tested-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191111132458.342979914@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf updates from Ingo Molnar:
"The main kernel side changes in this cycle were:
- Various Intel-PT updates and optimizations (Alexander Shishkin)
- Prohibit kprobes on Xen/KVM emulate prefixes (Masami Hiramatsu)
- Add support for LSM and SELinux checks to control access to the
perf syscall (Joel Fernandes)
- Misc other changes, optimizations, fixes and cleanups - see the
shortlog for details.
There were numerous tooling changes as well - 254 non-merge commits.
Here are the main changes - too many to list in detail:
- Enhancements to core tooling infrastructure, perf.data, libperf,
libtraceevent, event parsing, vendor events, Intel PT, callchains,
BPF support and instruction decoding.
- There were updates to the following tools:
perf annotate
perf diff
perf inject
perf kvm
perf list
perf maps
perf parse
perf probe
perf record
perf report
perf script
perf stat
perf test
perf trace
- And a lot of other changes: please see the shortlog and Git log for
more details"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (279 commits)
perf parse: Fix potential memory leak when handling tracepoint errors
perf probe: Fix spelling mistake "addrees" -> "address"
libtraceevent: Fix memory leakage in copy_filter_type
libtraceevent: Fix header installation
perf intel-bts: Does not support AUX area sampling
perf intel-pt: Add support for decoding AUX area samples
perf intel-pt: Add support for recording AUX area samples
perf pmu: When using default config, record which bits of config were changed by the user
perf auxtrace: Add support for queuing AUX area samples
perf session: Add facility to peek at all events
perf auxtrace: Add support for dumping AUX area samples
perf inject: Cut AUX area samples
perf record: Add aux-sample-size config term
perf record: Add support for AUX area sampling
perf auxtrace: Add support for AUX area sample recording
perf auxtrace: Move perf_evsel__find_pmu()
perf record: Add a function to test for kernel support for AUX area sampling
perf tools: Add kernel AUX area sampling definitions
perf/core: Make the mlock accounting simple again
perf report: Jump to symbol source view from total cycles view
...
Pull networking updates from David Miller:
"Another merge window, another pull full of stuff:
1) Support alternative names for network devices, from Jiri Pirko.
2) Introduce per-netns netdev notifiers, also from Jiri Pirko.
3) Support MSG_PEEK in vsock/virtio, from Matias Ezequiel Vara
Larsen.
4) Allow compiling out the TLS TOE code, from Jakub Kicinski.
5) Add several new tracepoints to the kTLS code, also from Jakub.
6) Support set channels ethtool callback in ena driver, from Sameeh
Jubran.
7) New SCTP events SCTP_ADDR_ADDED, SCTP_ADDR_REMOVED,
SCTP_ADDR_MADE_PRIM, and SCTP_SEND_FAILED_EVENT. From Xin Long.
8) Add XDP support to mvneta driver, from Lorenzo Bianconi.
9) Lots of netfilter hw offload fixes, cleanups and enhancements,
from Pablo Neira Ayuso.
10) PTP support for aquantia chips, from Egor Pomozov.
11) Add UDP segmentation offload support to igb, ixgbe, and i40e. From
Josh Hunt.
12) Add smart nagle to tipc, from Jon Maloy.
13) Support L2 field rewrite by TC offloads in bnxt_en, from Venkat
Duvvuru.
14) Add a flow mask cache to OVS, from Tonghao Zhang.
15) Add XDP support to ice driver, from Maciej Fijalkowski.
16) Add AF_XDP support to ice driver, from Krzysztof Kazimierczak.
17) Support UDP GSO offload in atlantic driver, from Igor Russkikh.
18) Support it in stmmac driver too, from Jose Abreu.
19) Support TIPC encryption and auth, from Tuong Lien.
20) Introduce BPF trampolines, from Alexei Starovoitov.
21) Make page_pool API more numa friendly, from Saeed Mahameed.
22) Introduce route hints to ipv4 and ipv6, from Paolo Abeni.
23) Add UDP segmentation offload to cxgb4, Rahul Lakkireddy"
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1857 commits)
libbpf: Fix usage of u32 in userspace code
mm: Implement no-MMU variant of vmalloc_user_node_flags
slip: Fix use-after-free Read in slip_open
net: dsa: sja1105: fix sja1105_parse_rgmii_delays()
macvlan: schedule bc_work even if error
enetc: add support Credit Based Shaper(CBS) for hardware offload
net: phy: add helpers phy_(un)lock_mdio_bus
mdio_bus: don't use managed reset-controller
ax88179_178a: add ethtool_op_get_ts_info()
mlxsw: spectrum_router: Fix use of uninitialized adjacency index
mlxsw: spectrum_router: After underlay moves, demote conflicting tunnels
bpf: Simplify __bpf_arch_text_poke poke type handling
bpf: Introduce BPF_TRACE_x helper for the tracing tests
bpf: Add bpf_jit_blinding_enabled for !CONFIG_BPF_JIT
bpf, testing: Add various tail call test cases
bpf, x86: Emit patchable direct jump as tail call
bpf: Constant map key tracking for prog array pokes
bpf: Add poke dependency tracking for prog array maps
bpf: Add initial poke descriptor table for jit images
bpf: Move owner type, jited info into array auxiliary data
...
-----BEGIN PGP SIGNATURE-----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=QCEy
-----END PGP SIGNATURE-----
Merge tag 'printk-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk updates from Petr Mladek:
- Allow to print symbolic error names via new %pe modifier.
- Use pr_warn() instead of the remaining pr_warning() calls. Fix
formatting of the related lines.
- Add VSPRINTF entry to MAINTAINERS.
* tag 'printk-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (32 commits)
checkpatch: don't warn about new vsprintf pointer extension '%pe'
MAINTAINERS: Add VSPRINTF
tools lib api: Renaming pr_warning to pr_warn
ASoC: samsung: Use pr_warn instead of pr_warning
lib: cpu_rmap: Use pr_warn instead of pr_warning
trace: Use pr_warn instead of pr_warning
dma-debug: Use pr_warn instead of pr_warning
vgacon: Use pr_warn instead of pr_warning
fs: afs: Use pr_warn instead of pr_warning
sh/intc: Use pr_warn instead of pr_warning
scsi: Use pr_warn instead of pr_warning
platform/x86: intel_oaktrail: Use pr_warn instead of pr_warning
platform/x86: asus-laptop: Use pr_warn instead of pr_warning
platform/x86: eeepc-laptop: Use pr_warn instead of pr_warning
oprofile: Use pr_warn instead of pr_warning
of: Use pr_warn instead of pr_warning
macintosh: Use pr_warn instead of pr_warning
idsn: Use pr_warn instead of pr_warning
ide: Use pr_warn instead of pr_warning
crypto: n2: Use pr_warn instead of pr_warning
...
Pull cgroup updates from Tejun Heo:
"There are several notable changes here:
- Single thread migrating itself has been optimized so that it
doesn't need threadgroup rwsem anymore.
- Freezer optimization to avoid unnecessary frozen state changes.
- cgroup ID unification so that cgroup fs ino is the only unique ID
used for the cgroup and can be used to directly look up live
cgroups through filehandle interface on 64bit ino archs. On 32bit
archs, cgroup fs ino is still the only ID in use but it is only
unique when combined with gen.
- selftest and other changes"
* 'for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (24 commits)
writeback: fix -Wformat compilation warnings
docs: cgroup: mm: Fix spelling of "list"
cgroup: fix incorrect WARN_ON_ONCE() in cgroup_setup_root()
cgroup: use cgrp->kn->id as the cgroup ID
kernfs: use 64bit inos if ino_t is 64bit
kernfs: implement custom exportfs ops and fid type
kernfs: combine ino/id lookup functions into kernfs_find_and_get_node_by_id()
kernfs: convert kernfs_node->id from union kernfs_node_id to u64
kernfs: kernfs_find_and_get_node_by_ino() should only look up activated nodes
kernfs: use dumber locking for kernfs_find_and_get_node_by_ino()
netprio: use css ID instead of cgroup ID
writeback: use ino_t for inodes in tracepoints
kernfs: fix ino wrap-around detection
kselftests: cgroup: Avoid the reuse of fd after it is deallocated
cgroup: freezer: don't change task and cgroups status unnecessarily
cgroup: use cgroup->last_bstat instead of cgroup->bstat_pending for consistency
cgroup: remove cgroup_enable_task_cg_lists() optimization
cgroup: pids: use atomic64_t for pids->limit
selftests: cgroup: Run test_core under interfering stress
selftests: cgroup: Add task migration tests
...
- On ARMv8 CPUs without hardware updates of the access flag, avoid
failing cow_user_page() on PFN mappings if the pte is old. The patches
introduce an arch_faults_on_old_pte() macro, defined as false on x86.
When true, cow_user_page() makes the pte young before attempting
__copy_from_user_inatomic().
- Covert the synchronous exception handling paths in
arch/arm64/kernel/entry.S to C.
- FTRACE_WITH_REGS support for arm64.
- ZONE_DMA re-introduced on arm64 to support Raspberry Pi 4
- Several kselftest cases specific to arm64, together with a MAINTAINERS
update for these files (moved to the ARM64 PORT entry).
- Workaround for a Neoverse-N1 erratum where the CPU may fetch stale
instructions under certain conditions.
- Workaround for Cortex-A57 and A72 errata where the CPU may
speculatively execute an AT instruction and associate a VMID with the
wrong guest page tables (corrupting the TLB).
- Perf updates for arm64: additional PMU topologies on HiSilicon
platforms, support for CCN-512 interconnect, AXI ID filtering in the
IMX8 DDR PMU, support for the CCPI2 uncore PMU in ThunderX2.
- GICv3 optimisation to avoid a heavy barrier when accessing the
ICC_PMR_EL1 register.
- ELF HWCAP documentation updates and clean-up.
- SMC calling convention conduit code clean-up.
- KASLR diagnostics printed during boot
- NVIDIA Carmel CPU added to the KPTI whitelist
- Some arm64 mm clean-ups: use generic free_initrd_mem(), remove stale
macro, simplify calculation in __create_pgd_mapping(), typos.
- Kconfig clean-ups: CMDLINE_FORCE to depend on CMDLINE, choice for
endinanness to help with allmodconfig.
-----BEGIN PGP SIGNATURE-----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=TPL9
-----END PGP SIGNATURE-----
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
"Apart from the arm64-specific bits (core arch and perf, new arm64
selftests), it touches the generic cow_user_page() (reviewed by
Kirill) together with a macro for x86 to preserve the existing
behaviour on this architecture.
Summary:
- On ARMv8 CPUs without hardware updates of the access flag, avoid
failing cow_user_page() on PFN mappings if the pte is old. The
patches introduce an arch_faults_on_old_pte() macro, defined as
false on x86. When true, cow_user_page() makes the pte young before
attempting __copy_from_user_inatomic().
- Covert the synchronous exception handling paths in
arch/arm64/kernel/entry.S to C.
- FTRACE_WITH_REGS support for arm64.
- ZONE_DMA re-introduced on arm64 to support Raspberry Pi 4
- Several kselftest cases specific to arm64, together with a
MAINTAINERS update for these files (moved to the ARM64 PORT entry).
- Workaround for a Neoverse-N1 erratum where the CPU may fetch stale
instructions under certain conditions.
- Workaround for Cortex-A57 and A72 errata where the CPU may
speculatively execute an AT instruction and associate a VMID with
the wrong guest page tables (corrupting the TLB).
- Perf updates for arm64: additional PMU topologies on HiSilicon
platforms, support for CCN-512 interconnect, AXI ID filtering in
the IMX8 DDR PMU, support for the CCPI2 uncore PMU in ThunderX2.
- GICv3 optimisation to avoid a heavy barrier when accessing the
ICC_PMR_EL1 register.
- ELF HWCAP documentation updates and clean-up.
- SMC calling convention conduit code clean-up.
- KASLR diagnostics printed during boot
- NVIDIA Carmel CPU added to the KPTI whitelist
- Some arm64 mm clean-ups: use generic free_initrd_mem(), remove
stale macro, simplify calculation in __create_pgd_mapping(), typos.
- Kconfig clean-ups: CMDLINE_FORCE to depend on CMDLINE, choice for
endinanness to help with allmodconfig"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (93 commits)
arm64: Kconfig: add a choice for endianness
kselftest: arm64: fix spelling mistake "contiguos" -> "contiguous"
arm64: Kconfig: make CMDLINE_FORCE depend on CMDLINE
MAINTAINERS: Add arm64 selftests to the ARM64 PORT entry
arm64: kaslr: Check command line before looking for a seed
arm64: kaslr: Announce KASLR status on boot
kselftest: arm64: fake_sigreturn_misaligned_sp
kselftest: arm64: fake_sigreturn_bad_size
kselftest: arm64: fake_sigreturn_duplicated_fpsimd
kselftest: arm64: fake_sigreturn_missing_fpsimd
kselftest: arm64: fake_sigreturn_bad_size_for_magic0
kselftest: arm64: fake_sigreturn_bad_magic
kselftest: arm64: add helper get_current_context
kselftest: arm64: extend test_init functionalities
kselftest: arm64: mangle_pstate_invalid_mode_el[123][ht]
kselftest: arm64: mangle_pstate_invalid_daif_bits
kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils
kselftest: arm64: extend toplevel skeleton Makefile
drivers/perf: hisi: update the sccl_id/ccl_id for certain HiSilicon platform
arm64: mm: reserve CMA and crashkernel in ZONE_DMA32
...
Currently, a lot of memory is wasted for architectures like MIPS when
init_ftrace_syscalls() allocates the array for syscalls using kcalloc.
This is because syscalls numbers start from 4000, 5000 or 6000 and
array elements up to that point are unused.
Fix this by using a data structure more suited to storing sparsely
populated arrays. The XARRAY data structure, implemented using radix
trees, is much more memory efficient for storing the syscalls in
question.
Link: http://lkml.kernel.org/r/20191115234314.21599-1-hnaveed@wavecomp.com
Signed-off-by: Hassan Naveed <hnaveed@wavecomp.com>
Reviewed-by: Paul Burton <paulburton@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Adding 2 new functions -
1) struct trace_array *trace_array_get_by_name(const char *name);
Return pointer to a trace array with given name. If it does not exist,
create and return pointer to the new trace array.
2) int trace_array_set_clr_event(struct trace_array *tr,
const char *system ,const char *event, bool enable);
Enable/Disable events to this trace array.
Additionally,
- To handle reference counters, export trace_array_put()
- Due to introduction of the above 2 new functions, we no longer need to
export - ftrace_set_clr_event & trace_array_create APIs.
Link: http://lkml.kernel.org/r/1574276919-11119-2-git-send-email-divya.indi@oracle.com
Signed-off-by: Divya Indi <divya.indi@oracle.com>
Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig
Link: http://lkml.kernel.org/r/20191120133807.12741-1-krzk@kernel.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The ftrace_graph_stub was created and points to ftrace_stub as a way to
assign the functon graph tracer function pointer to a stub function with a
different prototype than what ftrace_stub has and not trigger the C
verifier. The ftrace_graph_stub was created via the linker script
vmlinux.lds.h. Unfortunately, powerpc already uses the name
ftrace_graph_stub for its internal implementation of the function graph
tracer, and even though powerpc would still build, the change via the linker
script broke function tracer on powerpc from working.
By using the name ftrace_stub_graph, which does not exist anywhere else in
the kernel, this should not be a problem.
Link: https://lore.kernel.org/r/1573849732.5937.136.camel@lca.pw
Fixes: b83b43ffc6 ("fgraph: Fix function type mismatches of ftrace_graph_return using ftrace_stub")
Reorted-by: Qian Cai <cai@lca.pw>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If a direct ftrace callback is at a location that does not have any other
ftrace helpers attached to it, it is possible to simply just change the
text to call the new caller (if the architecture supports it). But this
requires special architecture code. Currently, modify_ftrace_direct() uses a
trick to add a stub ftrace callback to the location forcing it to call the
ftrace iterator. Then it can change the direct helper to call the new
function in C, and then remove the stub. Removing the stub will have the
location now call the new location that the direct helper is using.
The new helper function does the registering the stub trick, but is a weak
function, allowing an architecture to override it to do something a bit more
direct.
Link: https://lore.kernel.org/r/20191115215125.mbqv7taqnx376yed@ast-mbp.dhcp.thefacebook.com
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Both unregister_ftrace_direct() and modify_ftrace_direct() needs to
normalize the ip passed in to match the rec->ip, as it is acceptable to have
the ip on the ftrace call site but not the start. There are also common
validity checks with the record found by the ip, these should be done for
both unregister_ftrace_direct() and modify_ftrace_direct().
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As an instruction pointer passed into register_ftrace_direct() may just
exist on the ftrace call site, but may not be the start of the call site
itself, register_ftrace_direct() still needs to update test if a direct call
exists on the normalized site, as only one direct call is allowed at any one
time.
Fixes: 763e34e74b ("ftrace: Add register_ftrace_direct()")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The direct->count wasn't being updated properly, where it only was updated
when the first entry was added, but should be updated every time.
Fixes: 013bf0da04 ("ftrace: Add ftrace_find_direct_func()")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Increase the maximum allowed count of synthetic event fields from 16 to 32
in order to allow for larger-than-usual events.
Link: http://lkml.kernel.org/r/20191115091730.9192-1-dedekind1@gmail.com
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a new function modify_ftrace_direct() that will allow a user to update
an existing direct caller to a new trampoline, without missing hits due to
unregistering one and then adding another.
Link: https://lore.kernel.org/r/20191109022907.6zzo6orhxpt5n2sv@ast-mbp.dhcp.thefacebook.com
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The latency_fsnotify() stub when the function is not defined, was missing
the "inline".
Link: https://lore.kernel.org/r/20191115140213.74c5efe7@canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
There was a stray tab in the help text of the aforementioned config
option which showed like this:
The "print fmt" of the trace events will show the enum/sizeof names
instead of their values. This can cause problems for user space tools
...
in menuconfig. Remove it and end a sentence with a fullstop.
No functional changes.
Link: http://lkml.kernel.org/r/20191112174219.10933-1-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Without this, buffers can be printed with __print_array macro that has
no formatting options and can be hard to read. The other way is to
mimic formatting capability with multiple calls of trace event with one
call per row which gives performance impact and different timestamp in
each row.
Link: http://lkml.kernel.org/r/1573130738-29390-2-git-send-email-piotrx.maziarz@linux.intel.com
Signed-off-by: Piotr Maziarz <piotrx.maziarz@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Check whether the non-suffixed symbol is notrace, since suffixed
symbols are generated by the compilers for optimization. Based on
these suffixed symbols, notrace check might not work because
some of them are just a partial code of the original function.
(e.g. cold-cache (unlikely) code is separated from original
function as FUNCTION.cold.XX)
For example, without this fix,
# echo p device_add.cold.67 > /sys/kernel/debug/tracing/kprobe_events
sh: write error: Invalid argument
# cat /sys/kernel/debug/tracing/error_log
[ 135.491035] trace_kprobe: error: Failed to register probe event
Command: p device_add.cold.67
^
# dmesg | tail -n 1
[ 135.488599] trace_kprobe: Could not probe notrace function device_add.cold.67
With this,
# echo p device_add.cold.66 > /sys/kernel/debug/tracing/kprobe_events
# cat /sys/kernel/debug/kprobes/list
ffffffff81599de9 k device_add.cold.66+0x0 [DISABLED]
Actually, kprobe blacklist already did similar thing,
see within_kprobe_blacklist().
Link: http://lkml.kernel.org/r/157233790394.6706.18243942030937189679.stgit@devnote2
Fixes: 45408c4f92 ("tracing: kprobes: Prohibit probing on notrace function")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fail to allocate memory for tgid_map, because it requires order-6 page.
detail as:
c3 sh: page allocation failure: order:6,
mode:0x140c0c0(GFP_KERNEL), nodemask=(null)
c3 sh cpuset=/ mems_allowed=0
c3 CPU: 3 PID: 5632 Comm: sh Tainted: G W O 4.14.133+ #10
c3 Hardware name: Generic DT based system
c3 Backtrace:
c3 [<c010bdbc>] (dump_backtrace) from [<c010c08c>](show_stack+0x18/0x1c)
c3 [<c010c074>] (show_stack) from [<c0993c54>](dump_stack+0x84/0xa4)
c3 [<c0993bd0>] (dump_stack) from [<c0229858>](warn_alloc+0xc4/0x19c)
c3 [<c0229798>] (warn_alloc) from [<c022a6e4>](__alloc_pages_nodemask+0xd18/0xf28)
c3 [<c02299cc>] (__alloc_pages_nodemask) from [<c0248344>](kmalloc_order+0x20/0x38)
c3 [<c0248324>] (kmalloc_order) from [<c0248380>](kmalloc_order_trace+0x24/0x108)
c3 [<c024835c>] (kmalloc_order_trace) from [<c01e6078>](set_tracer_flag+0xb0/0x158)
c3 [<c01e5fc8>] (set_tracer_flag) from [<c01e6404>](trace_options_core_write+0x7c/0xcc)
c3 [<c01e6388>] (trace_options_core_write) from [<c0278b1c>](__vfs_write+0x40/0x14c)
c3 [<c0278adc>] (__vfs_write) from [<c0278e10>](vfs_write+0xc4/0x198)
c3 [<c0278d4c>] (vfs_write) from [<c027906c>](SyS_write+0x6c/0xd0)
c3 [<c0279000>] (SyS_write) from [<c01079a0>](ret_fast_syscall+0x0/0x54)
Switch to use kvcalloc to avoid unexpected allocation failures.
Link: http://lkml.kernel.org/r/1571888070-24425-1-git-send-email-chunyan.zhang@unisoc.com
Signed-off-by: Yuming Han <yuming.han@unisoc.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The C compiler is allowing more checks to make sure that function pointers
are assigned to the correct prototype function. Unfortunately, the function
graph tracer uses a special name with its assigned ftrace_graph_return
function pointer that maps to a stub function used by the function tracer
(ftrace_stub). The ftrace_graph_return variable is compared to the
ftrace_stub in some archs to know if the function graph tracer is enabled or
not. This means we can not just simply create a new function stub that
compares it without modifying all the archs.
Instead, have the linker script create a function_graph_stub that maps to
ftrace_stub, and this way we can define the prototype for it to match the
prototype of ftrace_graph_return, and make the compiler checks all happy!
Link: http://lkml.kernel.org/r/20191015090055.789a0aed@gandalf.local.home
Cc: linux-sh@vger.kernel.org
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As part of commit f45d1225ad ("tracing: Kernel access to Ftrace
instances") we exported certain functions. Here, we are adding some additional
NULL checks to ensure safe usage by users of these APIs.
Link: http://lkml.kernel.org/r/1565805327-579-4-git-send-email-divya.indi@oracle.com
Signed-off-by: Divya Indi <divya.indi@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
A trace array can be destroyed from userspace or kernel. Verify if the
trace array exists before proceeding to destroy/remove it.
Link: http://lkml.kernel.org/r/1565805327-579-3-git-send-email-divya.indi@oracle.com
Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Divya Indi <divya.indi@oracle.com>
[ Removed unneeded braces ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Declare the newly introduced and exported APIs in the header file -
include/linux/trace.h. Moving previous declarations from
kernel/trace/trace.h to include/linux/trace.h.
Link: http://lkml.kernel.org/r/1565805327-579-2-git-send-email-divya.indi@oracle.com
Signed-off-by: Divya Indi <divya.indi@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The event_class_ftrace_##call and event_##call do not seem
to be used outside of trace_export.c so make them both static
to avoid a number of sparse warnings:
kernel/trace/trace_entries.h:59:1: warning: symbol 'event_class_ftrace_function' was not declared. Should it be static?
kernel/trace/trace_entries.h:59:1: warning: symbol '__event_function' was not declared. Should it be static?
kernel/trace/trace_entries.h:77:1: warning: symbol 'event_class_ftrace_funcgraph_entry' was not declared. Should it be static?
kernel/trace/trace_entries.h:77:1: warning: symbol '__event_funcgraph_entry' was not declared. Should it be static?
kernel/trace/trace_entries.h:93:1: warning: symbol 'event_class_ftrace_funcgraph_exit' was not declared. Should it be static?
kernel/trace/trace_entries.h:93:1: warning: symbol '__event_funcgraph_exit' was not declared. Should it be static?
kernel/trace/trace_entries.h:129:1: warning: symbol 'event_class_ftrace_context_switch' was not declared. Should it be static?
kernel/trace/trace_entries.h:129:1: warning: symbol '__event_context_switch' was not declared. Should it be static?
kernel/trace/trace_entries.h:149:1: warning: symbol 'event_class_ftrace_wakeup' was not declared. Should it be static?
kernel/trace/trace_entries.h:149:1: warning: symbol '__event_wakeup' was not declared. Should it be static?
kernel/trace/trace_entries.h:171:1: warning: symbol 'event_class_ftrace_kernel_stack' was not declared. Should it be static?
kernel/trace/trace_entries.h:171:1: warning: symbol '__event_kernel_stack' was not declared. Should it be static?
kernel/trace/trace_entries.h:191:1: warning: symbol 'event_class_ftrace_user_stack' was not declared. Should it be static?
kernel/trace/trace_entries.h:191:1: warning: symbol '__event_user_stack' was not declared. Should it be static?
kernel/trace/trace_entries.h:214:1: warning: symbol 'event_class_ftrace_bprint' was not declared. Should it be static?
kernel/trace/trace_entries.h:214:1: warning: symbol '__event_bprint' was not declared. Should it be static?
kernel/trace/trace_entries.h:230:1: warning: symbol 'event_class_ftrace_print' was not declared. Should it be static?
kernel/trace/trace_entries.h:230:1: warning: symbol '__event_print' was not declared. Should it be static?
kernel/trace/trace_entries.h:247:1: warning: symbol 'event_class_ftrace_raw_data' was not declared. Should it be static?
kernel/trace/trace_entries.h:247:1: warning: symbol '__event_raw_data' was not declared. Should it be static?
kernel/trace/trace_entries.h:262:1: warning: symbol 'event_class_ftrace_bputs' was not declared. Should it be static?
kernel/trace/trace_entries.h:262:1: warning: symbol '__event_bputs' was not declared. Should it be static?
kernel/trace/trace_entries.h:277:1: warning: symbol 'event_class_ftrace_mmiotrace_rw' was not declared. Should it be static?
kernel/trace/trace_entries.h:277:1: warning: symbol '__event_mmiotrace_rw' was not declared. Should it be static?
kernel/trace/trace_entries.h:298:1: warning: symbol 'event_class_ftrace_mmiotrace_map' was not declared. Should it be static?
kernel/trace/trace_entries.h:298:1: warning: symbol '__event_mmiotrace_map' was not declared. Should it be static?
kernel/trace/trace_entries.h:322:1: warning: symbol 'event_class_ftrace_branch' was not declared. Should it be static?
kernel/trace/trace_entries.h:322:1: warning: symbol '__event_branch' was not declared. Should it be static?
kernel/trace/trace_entries.h:343:1: warning: symbol 'event_class_ftrace_hwlat' was not declared. Should it be static?
kernel/trace/trace_entries.h:343:1: warning: symbol '__event_hwlat' was not declared. Should it be static?
Link: http://lkml.kernel.org/r/20191015121012.18824-1-ben.dooks@codethink.co.uk
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.
Add additional header output for PREEMPT_RT.
Link: http://lkml.kernel.org/r/20191015191821.11479-34-bigeasy@linutronix.de
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This burst feature enables the user to generate a burst of
preempt/irqsoff latencies. This makes it possible to test whether we
are able to detect latencies that systematically occur very close to
each other.
The maximum burst size is 10. We also create 10 identical test
functions, so that we get 10 different backtraces; this is useful
when we want to test whether we can detect all the latencies in a
burst. Otherwise, there would be no easy way of differentiating
between which latency in a burst was captured by the tracer.
In addition, there is a sysfs trigger, so that it's not necessary to
reload the module to repeat the test. The trigger will appear as
/sys/kernel/preemptirq_delay_test/trigger in sysfs.
Link: http://lkml.kernel.org/r/20191008220824.7911-3-viktor.rosendahl@gmail.com
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Viktor Rosendahl (BMW) <viktor.rosendahl@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This patch implements the feature that the tracing_max_latency file,
e.g. /sys/kernel/debug/tracing/tracing_max_latency will receive
notifications through the fsnotify framework when a new latency is
available.
One particularly interesting use of this facility is when enabling
threshold tracing, through /sys/kernel/debug/tracing/tracing_thresh,
together with the preempt/irqsoff tracers. This makes it possible to
implement a user space program that can, with equal probability,
obtain traces of latencies that occur immediately after each other in
spite of the fact that the preempt/irqsoff tracers operate in overwrite
mode.
This facility works with the hwlat, preempt/irqsoff, and wakeup
tracers.
The tracers may call the latency_fsnotify() from places such as
__schedule() or do_idle(); this makes it impossible to call
queue_work() directly without risking a deadlock. The same would
happen with a softirq, kernel thread or tasklet. For this reason we
use the irq_work mechanism to call queue_work().
This patch creates a new workqueue. The reason for doing this is that
I wanted to use the WQ_UNBOUND and WQ_HIGHPRI flags. My thinking was
that WQ_UNBOUND might help with the latency in some important cases.
If we use:
queue_work(system_highpri_wq, &tr->fsnotify_work);
then the work will (almost) always execute on the same CPU but if we are
unlucky that CPU could be too busy while there could be another CPU in
the system that would be able to process the work soon enough.
queue_work_on() could be used to queue the work on another CPU but it
seems difficult to select the right CPU.
Link: http://lkml.kernel.org/r/20191008220824.7911-2-viktor.rosendahl@gmail.com
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Viktor Rosendahl (BMW) <viktor.rosendahl@gmail.com>
[ Added max() to have one compare for max latency ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Looking for ways to shrink the size of the dyn_ftrace structure, knowing the
information about how many pages and the number of groups of those pages, is
useful in working out the best ways to save on memory.
This adds one info print on how many groups of pages were used to allocate
the ftrace dyn_ftrace structures, and also shows the number of pages and
groups in the dyn_ftrace_total_info (which is used for debugging).
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As testing for direct calls from the function graph tracer adds a little
overhead (which is a lot when tracing every function), add a counter that
can be used to test if function_graph tracer needs to test for a direct
caller or not.
It would have been nicer if we could use a static branch, but the static
branch logic fails when used within the function graph tracer trampoline.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Yonghong Song