No new features this release. Mostly clean ups, restructuring and
documentation.
- Have ftrace_bug() show ftrace errors before the WARN, as the WARN will
reboot the box before the error messages are printed if panic_on_warn
is set.
- Have traceoff_on_warn disable tracing sooner (before prints)
- Write a message to the trace buffer that its being disabled when
disable_trace_on_warning() is set.
- Separate out synthetic events from histogram code to let it be used by
other parts of the kernel.
- More documentation on histogram design.
- Other small fixes and clean ups.
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Merge tag 'trace-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"No new features this release. Mostly clean ups, restructuring and
documentation.
- Have ftrace_bug() show ftrace errors before the WARN, as the WARN
will reboot the box before the error messages are printed if
panic_on_warn is set.
- Have traceoff_on_warn disable tracing sooner (before prints)
- Write a message to the trace buffer that its being disabled when
disable_trace_on_warning() is set.
- Separate out synthetic events from histogram code to let it be used
by other parts of the kernel.
- More documentation on histogram design.
- Other small fixes and clean ups"
* tag 'trace-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Remove obsolete PREEMPTIRQ_EVENTS kconfig option
tracing/doc: Fix ascii-art in histogram-design.rst
tracing: Add a trace print when traceoff_on_warning is triggered
ftrace,bug: Improve traceoff_on_warn
selftests/ftrace: Distinguish between hist and synthetic event checks
tracing: Move synthetic events to a separate file
tracing: Fix events.rst section numbering
tracing/doc: Fix typos in histogram-design.rst
tracing: Add hist_debug trace event files for histogram debugging
tracing: Add histogram-design document
tracing: Check state.disabled in synth event trace functions
tracing/probe: reverse arguments to list_add
tools/bootconfig: Add a summary of test cases and return error
ftrace: show debugging information when panic_on_warn set
Pull networking updates from David Miller:
1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
Augusto von Dentz.
2) Add GSO partial support to igc, from Sasha Neftin.
3) Several cleanups and improvements to r8169 from Heiner Kallweit.
4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
device self-test. From Andrew Lunn.
5) Start moving away from custom driver versions, use the globally
defined kernel version instead, from Leon Romanovsky.
6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.
7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.
8) Add sriov and vf support to hinic, from Luo bin.
9) Support Media Redundancy Protocol (MRP) in the bridging code, from
Horatiu Vultur.
10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.
11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
Dubroca. Also add ipv6 support for espintcp.
12) Lots of ReST conversions of the networking documentation, from Mauro
Carvalho Chehab.
13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
from Doug Berger.
14) Allow to dump cgroup id and filter by it in inet_diag code, from
Dmitry Yakunin.
15) Add infrastructure to export netlink attribute policies to
userspace, from Johannes Berg.
16) Several optimizations to sch_fq scheduler, from Eric Dumazet.
17) Fallback to the default qdisc if qdisc init fails because otherwise
a packet scheduler init failure will make a device inoperative. From
Jesper Dangaard Brouer.
18) Several RISCV bpf jit optimizations, from Luke Nelson.
19) Correct the return type of the ->ndo_start_xmit() method in several
drivers, it's netdev_tx_t but many drivers were using
'int'. From Yunjian Wang.
20) Add an ethtool interface for PHY master/slave config, from Oleksij
Rempel.
21) Add BPF iterators, from Yonghang Song.
22) Add cable test infrastructure, including ethool interfaces, from
Andrew Lunn. Marvell PHY driver is the first to support this
facility.
23) Remove zero-length arrays all over, from Gustavo A. R. Silva.
24) Calculate and maintain an explicit frame size in XDP, from Jesper
Dangaard Brouer.
25) Add CAP_BPF, from Alexei Starovoitov.
26) Support terse dumps in the packet scheduler, from Vlad Buslov.
27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.
28) Add devm_register_netdev(), from Bartosz Golaszewski.
29) Minimize qdisc resets, from Cong Wang.
30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
eliminate set_fs/get_fs calls. From Christoph Hellwig.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
selftests: net: ip_defrag: ignore EPERM
net_failover: fixed rollback in net_failover_open()
Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
vmxnet3: allow rx flow hash ops only when rss is enabled
hinic: add set_channels ethtool_ops support
selftests/bpf: Add a default $(CXX) value
tools/bpf: Don't use $(COMPILE.c)
bpf, selftests: Use bpf_probe_read_kernel
s390/bpf: Use bcr 0,%0 as tail call nop filler
s390/bpf: Maintain 8-byte stack alignment
selftests/bpf: Fix verifier test
selftests/bpf: Fix sample_cnt shared between two threads
bpf, selftests: Adapt cls_redirect to call csum_level helper
bpf: Add csum_level helper for fixing up csum levels
bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
crypto/chtls: IPv6 support for inline TLS
Crypto/chcr: Fixes a coccinile check error
Crypto/chcr: Fixes compilations warnings
...
These functions are not needed anymore because the vmalloc and ioremap
mappings are now synchronized when they are created or torn down.
Remove all callers and function definitions.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20200515140023.25469-7-joro@8bytes.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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.
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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
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>
- 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
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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
...
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
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.
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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 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>
A customer reported the following softlockup:
[899688.160002] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [test.sh:16464]
[899688.160002] CPU: 0 PID: 16464 Comm: test.sh Not tainted 4.12.14-6.23-azure #1 SLE12-SP4
[899688.160002] RIP: 0010:up_write+0x1a/0x30
[899688.160002] Kernel panic - not syncing: softlockup: hung tasks
[899688.160002] RIP: 0010:up_write+0x1a/0x30
[899688.160002] RSP: 0018:ffffa86784d4fde8 EFLAGS: 00000257 ORIG_RAX: ffffffffffffff12
[899688.160002] RAX: ffffffff970fea00 RBX: 0000000000000001 RCX: 0000000000000000
[899688.160002] RDX: ffffffff00000001 RSI: 0000000000000080 RDI: ffffffff970fea00
[899688.160002] RBP: ffffffffffffffff R08: ffffffffffffffff R09: 0000000000000000
[899688.160002] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8b59014720d8
[899688.160002] R13: ffff8b59014720c0 R14: ffff8b5901471090 R15: ffff8b5901470000
[899688.160002] tracing_read_pipe+0x336/0x3c0
[899688.160002] __vfs_read+0x26/0x140
[899688.160002] vfs_read+0x87/0x130
[899688.160002] SyS_read+0x42/0x90
[899688.160002] do_syscall_64+0x74/0x160
It caught the process in the middle of trace_access_unlock(). There is
no loop. So, it must be looping in the caller tracing_read_pipe()
via the "waitagain" label.
Crashdump analyze uncovered that iter->seq was completely zeroed
at this point, including iter->seq.seq.size. It means that
print_trace_line() was never able to print anything and
there was no forward progress.
The culprit seems to be in the code:
/* reset all but tr, trace, and overruns */
memset(&iter->seq, 0,
sizeof(struct trace_iterator) -
offsetof(struct trace_iterator, seq));
It was added by the commit 53d0aa7730 ("ftrace:
add logic to record overruns"). It was v2.6.27-rc1.
It was the time when iter->seq looked like:
struct trace_seq {
unsigned char buffer[PAGE_SIZE];
unsigned int len;
};
There was no "size" variable and zeroing was perfectly fine.
The solution is to reinitialize the structure after or without
zeroing.
Link: http://lkml.kernel.org/r/20191011142134.11997-1-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Added various checks on open tracefs calls to see if tracefs is in lockdown
mode, and if so, to return -EPERM.
Note, the event format files (which are basically standard on all machines)
as well as the enabled_functions file (which shows what is currently being
traced) are not lockde down. Perhaps they should be, but it seems counter
intuitive to lockdown information to help you know if the system has been
modified.
Link: http://lkml.kernel.org/r/CAHk-=wj7fGPKUspr579Cii-w_y60PtRaiDgKuxVtBAMK0VNNkA@mail.gmail.com
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Linus Torvalds