A function in kernel/bpf/syscall.c which got a bug fix in 'net'
was moved to kernel/bpf/verifier.c in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
I noticed that reading the snapshot file when it is empty no longer gives a
status. It suppose to show the status of the snapshot buffer as well as how
to allocate and use it. For example:
># cat snapshot
# tracer: nop
#
#
# * Snapshot is allocated *
#
# Snapshot commands:
# echo 0 > snapshot : Clears and frees snapshot buffer
# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.
# Takes a snapshot of the main buffer.
# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)
# (Doesn't have to be '2' works with any number that
# is not a '0' or '1')
But instead it just showed an empty buffer:
># cat snapshot
# tracer: nop
#
# entries-in-buffer/entries-written: 0/0 #P:4
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
What happened was that it was using the ring_buffer_iter_empty() function to
see if it was empty, and if it was, it showed the status. But that function
was returning false when it was empty. The reason was that the iter header
page was on the reader page, and the reader page was empty, but so was the
buffer itself. The check only tested to see if the iter was on the commit
page, but the commit page was no longer pointing to the reader page, but as
all pages were empty, the buffer is also.
Cc: stable@vger.kernel.org
Fixes: 651e22f270 ("ring-buffer: Always reset iterator to reader page")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently the snapshot trigger enables the probe and then allocates the
snapshot. If the probe triggers before the allocation, it could cause the
snapshot to fail and turn tracing off. It's best to allocate the snapshot
buffer first, and then enable the trigger. If something goes wrong in the
enabling of the trigger, the snapshot buffer is still allocated, but it can
also be freed by the user by writting zero into the snapshot buffer file.
Also add a check of the return status of alloc_snapshot().
Cc: stable@vger.kernel.org
Fixes: 77fd5c15e3 ("tracing: Add snapshot trigger to function probes")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As nothing outside the tracing directory uses the function probes mechanism,
I'm moving the prototypes out of the include/linux/ftrace.h and into the
local kernel/trace/trace.h header. I plan on making them hook to the
trace_array structure which is local to kernel/trace, and I do not want to
expose it to the rest of the kernel. This requires that the probe functions
must also be local to tracing. But luckily nothing else uses them.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The function-fork option is same as event-fork that it tracks task
fork/exit and set the pid filter properly. This can be useful if user
wants to trace selected tasks including their children only.
Link: http://lkml.kernel.org/r/20170417024430.21194-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When function tracer has a pid filter, it adds a probe to sched_switch
to track if current task can be ignored. The probe checks the
ftrace_ignore_pid from current tr to filter tasks. But it misses to
delete the probe when removing an instance so that it can cause a crash
due to the invalid tr pointer (use-after-free).
This is easily reproducible with the following:
# cd /sys/kernel/debug/tracing
# mkdir instances/buggy
# echo $$ > instances/buggy/set_ftrace_pid
# rmdir instances/buggy
============================================================================
BUG: KASAN: use-after-free in ftrace_filter_pid_sched_switch_probe+0x3d/0x90
Read of size 8 by task kworker/0:1/17
CPU: 0 PID: 17 Comm: kworker/0:1 Tainted: G B 4.11.0-rc3 #198
Call Trace:
dump_stack+0x68/0x9f
kasan_object_err+0x21/0x70
kasan_report.part.1+0x22b/0x500
? ftrace_filter_pid_sched_switch_probe+0x3d/0x90
kasan_report+0x25/0x30
__asan_load8+0x5e/0x70
ftrace_filter_pid_sched_switch_probe+0x3d/0x90
? fpid_start+0x130/0x130
__schedule+0x571/0xce0
...
To fix it, use ftrace_clear_pids() to unregister the probe. As
instance_rmdir() already updated ftrace codes, it can just free the
filter safely.
Link: http://lkml.kernel.org/r/20170417024430.21194-2-namhyung@kernel.org
Fixes: 0c8916c342 ("tracing: Add rmdir to remove multibuffer instances")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The trace_event benchmark thread runs in kernel space in an infinite loop
while also calling cond_resched() in case anything else wants to schedule
in. Unfortunately, on a PREEMPT kernel, that makes it a nop, in which case,
this will never voluntarily schedule. That will cause synchronize_rcu_tasks()
to forever block on this thread, while it is running.
This is exactly what cond_resched_rcu_qs() is for. Use that instead.
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
t_hash_start() does not increment *pos, where as t_next() must. But when
t_next() does increment *pos, it must still pass in the original *pos to
t_hash_start() otherwise it will skip the first instance:
# cd /sys/kernel/debug/tracing
# echo schedule:traceoff > set_ftrace_filter
# echo do_IRQ:traceoff > set_ftrace_filter
# echo call_rcu > set_ftrace_filter
# cat set_ftrace_filter
call_rcu
schedule:traceoff:unlimited
do_IRQ:traceoff:unlimited
The above called t_hash_start() from t_start() as there was only one
function (call_rcu), but if we add another function:
# echo xfrm_policy_destroy_rcu >> set_ftrace_filter
# cat set_ftrace_filter
call_rcu
xfrm_policy_destroy_rcu
do_IRQ:traceoff:unlimited
The "schedule:traceoff" disappears.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Conflicts were simply overlapping changes. In the net/ipv4/route.c
case the code had simply moved around a little bit and the same fix
was made in both 'net' and 'net-next'.
In the net/sched/sch_generic.c case a fix in 'net' happened at
the same time that a new argument was added to qdisc_hash_add().
Signed-off-by: David S. Miller <davem@davemloft.net>
There's no need to have struct bpf_prog_type_list since
it just contains a list_head, the type, and the ops
pointer. Since the types are densely packed and not
actually dynamically registered, it's much easier and
smaller to have an array of type->ops pointer. Also
initialize this array statically to remove code needed
to initialize it.
In order to save duplicating the list, move it to a new
header file and include it in the places needing it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tracing uses rcu_irq_enter() as a way to make sure that RCU is watching when
it needs to use rcu_read_lock() and friends. This is because tracing can
happen as RCU is about to enter user space, or about to go idle, and RCU
does not watch for RCU read side critical sections as it makes the
transition.
There is a small location within the RCU infrastructure that rcu_irq_enter()
itself will not work. If tracing were to occur in that section it will break
if it tries to use rcu_irq_enter().
Originally, this happens with the stack_tracer, because it will call
save_stack_trace when it encounters stack usage that is greater than any
stack usage it had encountered previously. There was a case where that
happened in the RCU section where rcu_irq_enter() did not work, and lockdep
complained loudly about it. To fix it, stack tracing added a call to be
disabled and RCU would disable stack tracing during the critical section
that rcu_irq_enter() was inoperable. This solution worked, but there are
other cases that use rcu_irq_enter() and it would be a good idea to let RCU
give a way to let others know that rcu_irq_enter() will not work. For
example, in trace events.
Another helpful aspect of this change is that it also moves the per cpu
variable called in the RCU critical section into a cache locale along with
other RCU per cpu variables used in that same location.
I'm keeping the stack_trace_disable() code, as that still could be used in
the future by places that really need to disable it. And since it's only a
static inline, it wont take up any kernel text if it is not used.
Link: http://lkml.kernel.org/r/20170405093207.404f8deb@gandalf.local.home
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In order to eliminate a function call, make "trace_active" into
"disable_stack_tracer" and convert stack_tracer_disable() and friends into
static inline functions.
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
There are certain parts of the kernel that cannot let stack tracing
proceed (namely in RCU), because the stack tracer uses RCU, and parts of RCU
internals cannot handle having RCU read side locks taken.
Add stack_tracer_disable() and stack_tracer_enable() functions to let RCU
stop stack tracing on the current CPU when it is in those critical sections.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The updates to the trace_active per cpu variable can be updated with the
__this_cpu_*() functions as it only gets updated on the CPU that the variable
is on.
Thanks to Paul McKenney for suggesting __this_cpu_* instead of this_cpu_*.
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The function tracer needs to be more careful than other subsystems when it
comes to freeing data. Especially if that data is actually executable code.
When a single function is traced, a trampoline can be dynamically allocated
which is called to jump to the function trace callback. When the callback is
no longer needed, the dynamic allocated trampoline needs to be freed. This
is where the issues arise. The dynamically allocated trampoline must not be
used again. As function tracing can trace all subsystems, including
subsystems that are used to serialize aspects of freeing (namely RCU), it
must take extra care when doing the freeing.
Before synchronize_rcu_tasks() was around, there was no way for the function
tracer to know that nothing was using the dynamically allocated trampoline
when CONFIG_PREEMPT was enabled. That's because a task could be indefinitely
preempted while sitting on the trampoline. Now with synchronize_rcu_tasks(),
it will wait till all tasks have either voluntarily scheduled (not on the
trampoline) or goes into userspace (not on the trampoline). Then it is safe
to free the trampoline even with CONFIG_PREEMPT set.
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In case of error, the function kthread_run() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check
should be replaced with IS_ERR().
Link: http://lkml.kernel.org/r/1466184839-14927-1-git-send-email-weiyj_lk@163.com
Cc: stable@vger.kernel.org
Fixes: 6c43e554a ("ring-buffer: Add ring buffer startup selftest")
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When a kretprobe is installed on a kernel function, there is a maximum
limit of how many calls in parallel it can catch (aka "maxactive"). A
kernel module could call register_kretprobe() and initialize maxactive
(see example in samples/kprobes/kretprobe_example.c).
But that is not exposed to userspace and it is currently not possible to
choose maxactive when writing to /sys/kernel/debug/tracing/kprobe_events
The default maxactive can be as low as 1 on single-core with a
non-preemptive kernel. This is too low and we need to increase it not
only for recursive functions, but for functions that sleep or resched.
This patch updates the format of the command that can be written to
kprobe_events so that maxactive can be optionally specified.
I need this for a bpf program attached to the kretprobe of
inet_csk_accept, which can sleep for a long time.
This patch includes a basic selftest:
> # ./ftracetest -v test.d/kprobe/
> === Ftrace unit tests ===
> [1] Kprobe dynamic event - adding and removing [PASS]
> [2] Kprobe dynamic event - busy event check [PASS]
> [3] Kprobe dynamic event with arguments [PASS]
> [4] Kprobes event arguments with types [PASS]
> [5] Kprobe dynamic event with function tracer [PASS]
> [6] Kretprobe dynamic event with arguments [PASS]
> [7] Kretprobe dynamic event with maxactive [PASS]
>
> # of passed: 7
> # of failed: 0
> # of unresolved: 0
> # of untested: 0
> # of unsupported: 0
> # of xfailed: 0
> # of undefined(test bug): 0
BugLink: https://github.com/iovisor/bcc/issues/1072
Link: http://lkml.kernel.org/r/1491215782-15490-1-git-send-email-alban@kinvolk.io
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Relying on free_reserved_area() to call ftrace to free init memory proved to
not be sufficient. The issue is that on x86, when debug_pagealloc is
enabled, the init memory is not freed, but simply set as not present. Since
ftrace was uninformed of this, starting function tracing still tries to
update pages that are not present according to the page tables, causing
ftrace to bug, as well as killing the kernel itself.
Instead of relying on free_reserved_area(), have init/main.c call ftrace
directly just before it frees the init memory. Then it needs to use
__init_begin and __init_end to know where the init memory location is.
Looking at all archs (and testing what I can), it appears that this should
work for each of them.
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
I noticed that if I use dd to read the set_ftrace_filter file that the first
hash command is repeated.
# cd /sys/kernel/debug/tracing
# echo schedule > set_ftrace_filter
# echo do_IRQ >> set_ftrace_filter
# echo schedule:traceoff >> set_ftrace_filter
# echo do_IRQ:traceoff >> set_ftrace_filter
# cat set_ftrace_filter
schedule
do_IRQ
schedule:traceoff:unlimited
do_IRQ:traceoff:unlimited
# dd if=set_ftrace_filter bs=1
schedule
do_IRQ
schedule:traceoff:unlimited
schedule:traceoff:unlimited
do_IRQ:traceoff:unlimited
98+0 records in
98+0 records out
98 bytes copied, 0.00265011 s, 37.0 kB/s
This is due to the way t_start() calls t_next() as well as the seq_file
calls t_next() and the state is slightly different between the two. Namely,
t_start() will call t_next() with a local "pos" variable.
By separating out the function listing from t_next() into its own function,
we can have better control of outputting the functions and the hash of
triggers. This simplifies the code.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If all functions are enabled, there's a comment displayed in the file to
denote that:
# cd /sys/kernel/debug/tracing
# cat set_ftrace_filter
#### all functions enabled ####
If a function trigger is set, those are displayed as well:
# echo schedule:traceoff >> /debug/tracing/set_ftrace_filter
# cat set_ftrace_filter
#### all functions enabled ####
schedule:traceoff:unlimited
But if you read that file with dd, the output can change:
# dd if=/debug/tracing/set_ftrace_filter bs=1
#### all functions enabled ####
32+0 records in
32+0 records out
32 bytes copied, 7.0237e-05 s, 456 kB/s
This is because the "pos" variable is updated for the comment, but func_pos
is not. "func_pos" is used by the triggers (or hashes) to know how many
functions were printed and it bases its index from the pos - func_pos.
func_pos should be 1 to count for the comment printed. But since it is not,
t_hash_start() thinks that one trigger was already printed.
The cat gets to t_hash_start() via t_next() and not t_start() which updates
both pos and func_pos.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The loop in t_start() of calling t_next() will call t_hash_start() if the
pos is beyond the functions and enters the hash items. There's no reason to
check if p is NULL and call t_hash_start(), as that would be redundant.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Instead of testing if the hash to use is the filter_hash or the notrace_hash
at each iteration, do the test at open, and set the iter->hash to point to
the corresponding filter or notrace hash. Then use that directly instead of
testing which hash needs to be used each iteration.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The return status check of __seq_open_private() is rather strange:
iter = __seq_open_private();
if (iter) {
/* do stuff */
}
return iter ? 0 : -ENOMEM;
It makes much more sense to do the return of failure right away:
iter = __seq_open_private();
if (!iter)
return -ENOMEM;
/* do stuff */
return 0;
This clean up will make updates to this code a bit nicer.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently trace_handle_return() looks like this:
static inline enum print_line_t trace_handle_return(struct trace_seq *s)
{
return trace_seq_has_overflowed(s) ?
TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
}
Where trace_seq_overflowed(s) is:
static inline bool trace_seq_has_overflowed(struct trace_seq *s)
{
return s->full || seq_buf_has_overflowed(&s->seq);
}
And seq_buf_has_overflowed(&s->seq) is:
static inline bool
seq_buf_has_overflowed(struct seq_buf *s)
{
return s->len > s->size;
}
Making trace_handle_return() into:
return (s->full || (s->seq->len > s->seq->size)) ?
TRACE_TYPE_PARTIAL_LINE :
TRACE_TYPE_HANDLED;
One would think this is not an issue to keep as an inline. But because this
is used in the TRACE_EVENT() macro, it is extended for every tracepoint in
the system. Taking a look at a single tracepoint x86_irq_vector (was the
first one I randomly chosen). As trace_handle_return is used in the
TRACE_EVENT() macro of trace_raw_output_##call() we disassemble
trace_raw_output_x86_irq_vector and do a diff:
- is the original
+ is the out-of-line code
I removed identical lines that were different just due to different
addresses.
--- /tmp/irq-vec-orig 2017-03-16 09:12:48.569384851 -0400
+++ /tmp/irq-vec-ool 2017-03-16 09:13:39.378153385 -0400
@@ -6,27 +6,23 @@
53 push %rbx
48 89 fb mov %rdi,%rbx
4c 8b a7 c0 20 00 00 mov 0x20c0(%rdi),%r12
e8 f7 72 13 00 callq ffffffff81155c80 <trace_raw_output_prep>
83 f8 01 cmp $0x1,%eax
74 05 je ffffffff8101e993 <trace_raw_output_x86_irq_vector+0x23>
5b pop %rbx
41 5c pop %r12
5d pop %rbp
c3 retq
41 8b 54 24 08 mov 0x8(%r12),%edx
- 48 8d bb 98 10 00 00 lea 0x1098(%rbx),%rdi
+ 48 81 c3 98 10 00 00 add $0x1098,%rbx
- 48 c7 c6 7b 8a a0 81 mov $0xffffffff81a08a7b,%rsi
+ 48 c7 c6 ab 8a a0 81 mov $0xffffffff81a08aab,%rsi
- e8 c5 85 13 00 callq ffffffff81156f70 <trace_seq_printf>
=== here's the start of the main difference ===
+ 48 89 df mov %rbx,%rdi
+ e8 62 7e 13 00 callq ffffffff81156810 <trace_seq_printf>
- 8b 93 b8 20 00 00 mov 0x20b8(%rbx),%edx
- 31 c0 xor %eax,%eax
- 85 d2 test %edx,%edx
- 75 11 jne ffffffff8101e9c8 <trace_raw_output_x86_irq_vector+0x58>
- 48 8b 83 a8 20 00 00 mov 0x20a8(%rbx),%rax
- 48 39 83 a0 20 00 00 cmp %rax,0x20a0(%rbx)
- 0f 93 c0 setae %al
+ 48 89 df mov %rbx,%rdi
+ e8 4a c5 12 00 callq ffffffff8114af00 <trace_handle_return>
5b pop %rbx
- 0f b6 c0 movzbl %al,%eax
=== end ===
41 5c pop %r12
5d pop %rbp
c3 retq
If you notice, the original has 22 bytes of text more than the out of line
version. As this is for every TRACE_EVENT() defined in the system, this can
become quite large.
text data bss dec hex filename
8690305 5450490 1298432 15439227 eb957b vmlinux-orig
8681725 5450490 1298432 15430647 eb73f7 vmlinux-handle
This change has a total of 8580 bytes in savings.
$ objdump -dr /tmp/vmlinux-orig | grep '^[0-9a-f]* <trace_raw_output' | wc -l
324
That's 324 tracepoints. But this does not include modules (which contain
many more tracepoints). For an allyesconfig build:
$ objdump -dr vmlinux-allyes-orig | grep '^[0-9a-f]* <trace_raw_output' | wc -l
1401
That's 1401 tracepoints giving us:
text data bss dec hex filename
137920629 140221067 53264384 331406080 13c0db00 vmlinux-allyes-orig
137827709 140221067 53264384 331313160 13bf7008 vmlinux-allyes-handle
92920 bytes in savings!!!
Link: http://lkml.kernel.org/r/20170315021431.13107-2-andi@firstfloor.org
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Adding a hook into free_reserve_area() that informs ftrace that boot up init
text is being free, lets ftrace safely remove those init functions from its
records, which keeps ftrace from trying to modify text that no longer
exists.
Note, this still does not allow for tracing .init text of modules, as
modules require different work for freeing its init code.
Link: http://lkml.kernel.org/r/1488502497.7212.24.camel@linux.intel.com
Cc: linux-mm@kvack.org
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Requested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Register the function tracer right after the tracing buffers are initialized
in early boot up. This will allow function tracing to begin early if it is
enabled via the kernel command line.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As tracing can now be enabled very early in boot up, even before some
critical system services (like scheduling), do not run the tracer selftests
until after early_initcall() is performed. If a tracer is registered before
such time, it is saved off in a list and the test is run when the system is
able to handle more diverse functions.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Create an early_trace_init() function that will initialize the buffers and
allow for ealier use of trace_printk(). This will also allow for future work
to have function tracing start earlier at boot up.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
New features:
- Add 'brstackinsn' field in 'perf script' to reuse the x86 instruction
decoder used in the Intel PT code to study hot paths to samples (Andi Kleen)
Kernel:
- Default UPROBES_EVENTS to Y (Alexei Starovoitov)
- Fix check for kretprobe offset within function entry (Naveen N. Rao)
Infrastructure:
- Introduce util func is_sdt_event() (Ravi Bangoria)
- Make perf_event__synthesize_mmap_events() scale on older kernels where
reading /proc/pid/maps is way slower than reading /proc/pid/task/pid/maps (Stephane Eranian)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2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=Bg5M
-----END PGP SIGNATURE-----
Merge tag 'perf-core-for-mingo-4.12-20170316' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
New features:
- Add 'brstackinsn' field in 'perf script' to reuse the x86 instruction
decoder used in the Intel PT code to study hot paths to samples (Andi Kleen)
Kernel changes:
- Default UPROBES_EVENTS to Y (Alexei Starovoitov)
- Fix check for kretprobe offset within function entry (Naveen N. Rao)
Infrastructure changes:
- Introduce util func is_sdt_event() (Ravi Bangoria)
- Make perf_event__synthesize_mmap_events() scale on older kernels where
reading /proc/pid/maps is way slower than reading /proc/pid/task/pid/maps (Stephane Eranian)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As it is already turned on by most distros, so just flip the default to
Y.
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: David Miller <davem@davemloft.net>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170316005817.GA6805@ast-mbp.thefacebook.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf specifies an offset from _text and since this offset is fed
directly into the arch-specific helper, kprobes tracer rejects
installation of kretprobes through perf. Fix this by looking up the
actual offset from a function for the specified sym+offset.
Refactor and reuse existing routines to limit code duplication -- we
repurpose kprobe_addr() for determining final kprobe address and we
split out the function entry offset determination into a separate
generic helper.
Before patch:
naveen@ubuntu:~/linux/tools/perf$ sudo ./perf probe -v do_open%return
probe-definition(0): do_open%return
symbol:do_open file:(null) line:0 offset:0 return:1 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /boot/vmlinux for symbols
Open Debuginfo file: /boot/vmlinux
Try to find probe point from debuginfo.
Matched function: do_open [2d0c7ff]
Probe point found: do_open+0
Matched function: do_open [35d76dc]
found inline addr: 0xc0000000004ba9c4
Failed to find "do_open%return",
because do_open is an inlined function and has no return point.
An error occurred in debuginfo analysis (-22).
Trying to use symbols.
Opening /sys/kernel/debug/tracing//README write=0
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: r:probe/do_open _text+4469776
Failed to write event: Invalid argument
Error: Failed to add events. Reason: Invalid argument (Code: -22)
naveen@ubuntu:~/linux/tools/perf$ dmesg | tail
<snip>
[ 33.568656] Given offset is not valid for return probe.
After patch:
naveen@ubuntu:~/linux/tools/perf$ sudo ./perf probe -v do_open%return
probe-definition(0): do_open%return
symbol:do_open file:(null) line:0 offset:0 return:1 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /boot/vmlinux for symbols
Open Debuginfo file: /boot/vmlinux
Try to find probe point from debuginfo.
Matched function: do_open [2d0c7d6]
Probe point found: do_open+0
Matched function: do_open [35d76b3]
found inline addr: 0xc0000000004ba9e4
Failed to find "do_open%return",
because do_open is an inlined function and has no return point.
An error occurred in debuginfo analysis (-22).
Trying to use symbols.
Opening /sys/kernel/debug/tracing//README write=0
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: r:probe/do_open _text+4469808
Writing event: r:probe/do_open_1 _text+4956344
Added new events:
probe:do_open (on do_open%return)
probe:do_open_1 (on do_open%return)
You can now use it in all perf tools, such as:
perf record -e probe:do_open_1 -aR sleep 1
naveen@ubuntu:~/linux/tools/perf$ sudo cat /sys/kernel/debug/kprobes/list
c000000000041370 k kretprobe_trampoline+0x0 [OPTIMIZED]
c0000000004ba0b8 r do_open+0x8 [DISABLED]
c000000000443430 r do_open+0x0 [DISABLED]
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/d8cd1ef420ec22e3643ac332fdabcffc77319a42.1488961018.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix typos and add the following to the scripts/spelling.txt:
overide||override
While we are here, fix the doubled "address" in the touched line
Documentation/devicetree/bindings/regulator/ti-abb-regulator.txt.
Also, fix the comment block style in the touched hunks in
drivers/media/dvb-frontends/drx39xyj/drx_driver.h.
Link: http://lkml.kernel.org/r/1481573103-11329-21-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull perf fixes from Ingo Molnar:
"This includes a fix for a crash if certain special addresses are
kprobed, plus does a rename of two Kconfig variables that were a minor
misnomer"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS
kprobes/x86: Fix kernel panic when certain exception-handling addresses are probed
window. Namely powerpc broke as jump labels uses the two LSB bits as flags
in initialization. A check was added to make sure that all jump label
entries were 4 bytes aligned, but powerpc didn't work that way for modules.
Adding an alignment in the module linker script appeared to be the best
solution.
Jump labels also added an anonymous union to access those LSB bits as a
normal long. But because this structure had static initialization, it broke
older compilers that could not statically initialize anonymous unions
without brackets.
The command line parameter for setting function graph filter broke the
"EMPTY_HASH" descriptor by modifying it instead of creating a new hash to
hold the entries.
The command line parameter ftrace_graph_max_depth was added to allow its
setting at boot time. It uses existing code and only the command line hook
was added. This is not really a fix, but as it uses existing code without
affecting anything else, I added it to this release. It was ready before the
merge window closed, but I wanted to let it sit in linux-next for a couple
of days first.
-----BEGIN PGP SIGNATURE-----
iQExBAABCAAbBQJYvNrAFBxyb3N0ZWR0QGdvb2RtaXMub3JnAAoJEMm5BfJq2Y3L
JGQIAMkayeZ0OCyYHRPR4EcCrdE3fATmt1huJWHrMPnT4/fLabL8XQqrOpnOBMq1
GFZb1SMkBmvGtAHF4GbvCxnIUfDQko6BTQAd8EMea1WM8+Kb66/BLgJawjWIU9I0
dNYre9ONgR2NOzkz6nfKRXnmy0lRcOweBb09YYGSzY11Md7d8T3T4TUrPNZdYrO9
8ZMbF4qRd9KLMRHcsWqvhWhBISxWnmtUSlthfweukKgDMy8OKpb7pR0ckjtYwsWX
RF41jqLqzSUqtd/nE2Sj/aT8XOP4pfrKEUuNM4SBj8q5jmNcZuqi8Q9wItu3LWR2
jqM/9UKTzaCr9cchwuvUC0i+jWc=
=kDql
-----END PGP SIGNATURE-----
Merge tag 'trace-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"There was some breakage with the changes for jump labels in the 4.11
merge window:
- powerpc broke as jump labels uses the two LSB bits as flags in
initialization.
A check was added to make sure that all jump label entries were 4
bytes aligned, but powerpc didn't work that way for modules. Adding
an alignment in the module linker script appeared to be the best
solution.
- Jump labels also added an anonymous union to access those LSB bits
as a normal long. But because this structure had static
initialization, it broke older compilers that could not statically
initialize anonymous unions without brackets.
- The command line parameter for setting function graph filter broke
the "EMPTY_HASH" descriptor by modifying it instead of creating a
new hash to hold the entries.
- The command line parameter ftrace_graph_max_depth was added to
allow its setting at boot time. It uses existing code and only the
command line hook was added.
This is not really a fix, but as it uses existing code without
affecting anything else, I added it to this release. It was ready
before the merge window closed, but I wanted to let it sit in
linux-next for a couple of days first"
* tag 'trace-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace/graph: Add ftrace_graph_max_depth kernel parameter
tracing: Add #undef to fix compile error
jump_label: Add comment about initialization order for anonymous unions
jump_label: Fix anonymous union initialization
module: set __jump_table alignment to 8
ftrace/graph: Do not modify the EMPTY_HASH for the function_graph filter
tracing: Fix code comment for ftrace_ops_get_func()
New features:
- Allow sorting by symbol_size in 'perf report' and 'perf top' (Charles Baylis)
E.g.:
# perf report -s symbol_size,symbol
Samples: 9K of event 'cycles:k', Event count (approx.): 2870461623
Overhead Symbol size Symbol
14.55% 326 [k] flush_tlb_mm_range
7.20% 1045 [k] filemap_map_pages
5.82% 124 [k] vma_interval_tree_insert
5.18% 2430 [k] unmap_page_range
2.57% 571 [k] vma_interval_tree_remove
1.94% 494 [k] page_add_file_rmap
1.82% 740 [k] page_remove_rmap
1.66% 1017 [k] release_pages
1.57% 1636 [k] update_blocked_averages
1.57% 76 [k] unlock_page
- Add support for -p/--pid, -a/--all-cpus and -C/--cpu in 'perf ftrace' (Namhyung Kim)
Change in behaviour:
- Make system wide (-a) the default option if no target was specified and one
of following conditions is met:
- No workload specified (current behaviour)
- A workload is specified but all requested events are system wide ones,
like uncore ones. (Jiri Olsa)
Fixes:
- Add missing initialization to the instruction decoder used in the
intel PT/BTS code, which was causing lots of failures in 'perf test',
looking for a value when there was none (Adrian Hunter)
Infrastructure:
- Add arch code needed to adopt the kernel's refcount_t to aid in
catching bugs when using atomic_t as a reference counter, basically
cmpxchg related functions (Arnaldo Carvalho de Melo)
- Convert the code using atomic_t as reference counts to refcount_t
(Elena Rashetova)
- Add feature test for sched_getcpu() to more easily check for its
presence in the many libc implementations and accross different
versions of such C libraries (Arnaldo Carvalho de Melo)
- Issue a HW watchdog disable hint in 'perf stat' for when some of the
requested events can't get counted because a PMU counter is taken by that
watchdog (Borislav Petkov).
- Add mapping for Intel's KnightsMill PMU events (Karol Wachowski)
Documentation:
- Clarify the term 'convergence' in:
perf bench numa numa-mem -h --show_convergence (Jiri Olsa)
Kernel code:
- Ensure probe location is at function entry in kretprobes (Naveen N. Rao)
- Allow return probes with offsets and absolute addresses (Naveen N. Rao)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2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=h2yo
-----END PGP SIGNATURE-----
Merge tag 'perf-core-for-mingo-4.11-20170306' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
New features:
- Allow sorting by symbol_size in 'perf report' and 'perf top' (Charles Baylis)
E.g.:
# perf report -s symbol_size,symbol
Samples: 9K of event 'cycles:k', Event count (approx.): 2870461623
Overhead Symbol size Symbol
14.55% 326 [k] flush_tlb_mm_range
7.20% 1045 [k] filemap_map_pages
5.82% 124 [k] vma_interval_tree_insert
5.18% 2430 [k] unmap_page_range
2.57% 571 [k] vma_interval_tree_remove
1.94% 494 [k] page_add_file_rmap
1.82% 740 [k] page_remove_rmap
1.66% 1017 [k] release_pages
1.57% 1636 [k] update_blocked_averages
1.57% 76 [k] unlock_page
- Add support for -p/--pid, -a/--all-cpus and -C/--cpu in 'perf ftrace' (Namhyung Kim)
Change in behaviour:
- Make system wide (-a) the default option if no target was specified and one
of following conditions is met:
- No workload specified (current behaviour)
- A workload is specified but all requested events are system wide ones,
like uncore ones. (Jiri Olsa)
Fixes:
- Add missing initialization to the instruction decoder used in the
intel PT/BTS code, which was causing lots of failures in 'perf test',
looking for a value when there was none (Adrian Hunter)
Infrastructure changes:
- Add arch code needed to adopt the kernel's refcount_t to aid in
catching bugs when using atomic_t as a reference counter, basically
cmpxchg related functions (Arnaldo Carvalho de Melo)
- Convert the code using atomic_t as reference counts to refcount_t
(Elena Rashetova)
- Add feature test for sched_getcpu() to more easily check for its
presence in the many libc implementations and accross different
versions of such C libraries (Arnaldo Carvalho de Melo)
- Issue a HW watchdog disable hint in 'perf stat' for when some of the
requested events can't get counted because a PMU counter is taken by that
watchdog (Borislav Petkov).
- Add mapping for Intel's KnightsMill PMU events (Karol Wachowski)
Documentation changes:
- Clarify the term 'convergence' in:
perf bench numa numa-mem -h --show_convergence (Jiri Olsa)
Kernel code changes:
- Ensure probe location is at function entry in kretprobes (Naveen N. Rao)
- Allow return probes with offsets and absolute addresses (Naveen N. Rao)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Let's not remove the warning about offsets and return probes when the
offset is invalid.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170227115204.00f92846@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since the kernel includes many non-global functions with same names, we
will need to use offsets from other symbols (typically _text/_stext) or
absolute addresses to place return probes on specific functions. Also,
the core register_kretprobe() API never forbid use of offsets or
absolute addresses with kretprobes.
Allow its use with the trace infrastructure. To distinguish kernels that
support this, update ftrace README to explicitly call this out.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/183e7ce2921a08c9c755ee9a5da3134febc6695b.1487770934.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Early trace callgraphs can be extremely large on systems with
several seconds of boot time. The max_depth parameter limits how
deep the graph trace goes and reduces the output size. This
parameter is the same as the max_graph_depth file in tracefs.
Link: http://lkml.kernel.org/r/1488499935-23216-1-git-send-email-todd.e.brandt@linux.intel.com
Signed-off-by: Todd Brandt <todd.e.brandt@linux.intel.com>
[ changed comments about debugfs to tracefs ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
On boot up, if the kernel command line sets a graph funtion with the kernel
command line options "ftrace_graph_filter" or "ftrace_graph_notrace" then it
updates the corresponding function graph hash, ftrace_graph_hash or
ftrace_graph_notrace_hash respectively. Unfortunately, at boot up, these
variables are pointers to the "EMPTY_HASH" which is a constant used as a
placeholder when a hash has no entities. The problem was that the comand
line version to set the hashes updated the actual EMPTY_HASH instead of
creating a new hash for the function graph. This broke the EMPTY_HASH
because not only did it modify a constant (not sure how that was allowed to
happen, except maybe because it was done at early boot, const variables were
still mutable), but it made the filters have functions listed in them when
they were actually empty.
The kernel command line function needs to allocate a new hash for the
function graph filters and assign the necessary variables to that new hash
instead.
Link: http://lkml.kernel.org/r/1488420091.7212.17.camel@linux.intel.com
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: b9b0c831be ("ftrace: Convert graph filter to use hash tables")
Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
We don't actually need the full rculist.h header in sched.h anymore,
we will be able to include the smaller rcupdate.h header instead.
But first update code that relied on the implicit header inclusion.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task_stack.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/task.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/mm.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
The APIs that are going to be moved first are:
mm_alloc()
__mmdrop()
mmdrop()
mmdrop_async_fn()
mmdrop_async()
mmget_not_zero()
mmput()
mmput_async()
get_task_mm()
mm_access()
mm_release()
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to move scheduler ABI details to <uapi/linux/sched/types.h>,
which will be used from a number of .c files.
Create empty placeholder header that maps to <linux/types.h>.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which
will have to be picked up from other headers and .c files.
Create a trivial placeholder <linux/sched/clock.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We have uses of CONFIG_UPROBE_EVENT and CONFIG_KPROBE_EVENT as
well as CONFIG_UPROBE_EVENTS and CONFIG_KPROBE_EVENTS.
Consistently use the plurals.
Signed-off-by: Anton Blanchard <anton@samba.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: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: davem@davemloft.net
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20170216060050.20866-1-anton@ozlabs.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
bug that was caused by a race condition in initializing the hwlat
thread. When fixing this code, I realized that it should have been done
differently. Instead of doing the rewrite and sending that to stable,
I just sent the above commit to fix the bug that should be back ported.
This commit is on top of the quick fix commit to rewrite the code the
way it should have been written in the first place.
-----BEGIN PGP SIGNATURE-----
iQExBAABCAAbBQJYtDsNFBxyb3N0ZWR0QGdvb2RtaXMub3JnAAoJEMm5BfJq2Y3L
+CQH/0BhSwjiCnlHAkHNFKn47O0yDtxBLj8ar4bUQRacDXeQyAGDP13hn3q3LvG9
CRzDXaYrusA3fjGcgmtyU33am6LK84dPn5u2HSyEalDZNBel8l6oYLUZVWLgef02
x43949nOeBy+KO02Y118zGyxFEPtYBnCVpguMa4vdVgnr04gECo2VH5FjnLMslKM
W1j/WrbVaO8WObh7X01JZzozWwp3McW4x6H8PUWaHjnhN/Iv6+YGtNN/Sa4cq4V/
CyCfxrZvN/Y/uMSGzVlhuXxeRc2PRsjjmAqN+8P4KZIGW5BstdiWbrVj+KaBLR9z
6QERD3atiEIYI/QGEep7ZH795PI=
=Bdwk
-----END PGP SIGNATURE-----
Merge tag 'trace-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull another tracing update from Steven Rostedt:
"Commit 79c6f448c8 ("tracing: Fix hwlat kthread migration") fixed a
bug that was caused by a race condition in initializing the hwlat
thread. When fixing this code, I realized that it should have been
done differently. Instead of doing the rewrite and sending that to
stable, I just sent the above commit to fix the bug that should be
back ported.
This commit is on top of the quick fix commit to rewrite the code the
way it should have been written in the first place"
* tag 'trace-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Clean up the hwlat binding code
and small optimizations.
-----BEGIN PGP SIGNATURE-----
iQExBAABCAAbBQJYtDiAFBxyb3N0ZWR0QGdvb2RtaXMub3JnAAoJEMm5BfJq2Y3L
KygH/3sxuM9MCeJ29JsjmV49fHcNqryNZdvSadmnysPm+dFPiI6IgIIbh5R8H89b
2V2gfQSmOTKHu3/wvJr/MprkGP275sWlZPORYFLDl/+NE/3q7g0NKOMWunLcv6dH
QQRJIFjSMeGawA3KYBEcwBYMlgNd2VgtTxqLqSBhWth5omV6UevJNHhe3xzZ4nEE
YbRX2mxwOuRHOyFp0Hem+Bqro4z1VXJ6YDxOvae2PP8krrIhIHYw9EI22GK68a2g
EyKqKPPaEzfU8IjHIQCqIZta5RufnCrDbfHU0CComPANBRGO7g+ZhLO11a/Z316N
lyV7JqtF680iem7NKcQlwEwhlLE=
=HJnl
-----END PGP SIGNATURE-----
Merge tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"This release has no new tracing features, just clean ups, minor fixes
and small optimizations"
* tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (25 commits)
tracing: Remove outdated ring buffer comment
tracing/probes: Fix a warning message to show correct maximum length
tracing: Fix return value check in trace_benchmark_reg()
tracing: Use modern function declaration
jump_label: Reduce the size of struct static_key
tracing/probe: Show subsystem name in messages
tracing/hwlat: Update old comment about migration
timers: Make flags output in the timer_start tracepoint useful
tracing: Have traceprobe_probes_write() not access userspace unnecessarily
tracing: Have COMM event filter key be treated as a string
ftrace: Have set_graph_function handle multiple functions in one write
ftrace: Do not hold references of ftrace_graph_{notrace_}hash out of graph_lock
tracing: Reset parser->buffer to allow multiple "puts"
ftrace: Have set_graph_functions handle write with RDWR
ftrace: Reset fgd->hash in ftrace_graph_write()
ftrace: Replace (void *)1 with a meaningful macro name FTRACE_GRAPH_EMPTY
ftrace: Create a slight optimization on searching the ftrace_hash
tracing: Add ftrace_hash_key() helper function
ftrace: Convert graph filter to use hash tables
ftrace: Expose ftrace_hash_empty and ftrace_lookup_ip
...
There is no function 'ftrace_ops_recurs_func' existing in the current code,
it was renamed to ftrace_ops_assist_func() in commit c68c0fa293
("ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too").
Update the comment to the correct function name.
Link: http://lkml.kernel.org/r/1487723366-14463-1-git-send-email-chuhu@redhat.com
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull namespace updates from Eric Biederman:
"There is a lot here. A lot of these changes result in subtle user
visible differences in kernel behavior. I don't expect anything will
care but I will revert/fix things immediately if any regressions show
up.
From Seth Forshee there is a continuation of the work to make the vfs
ready for unpriviled mounts. We had thought the previous changes
prevented the creation of files outside of s_user_ns of a filesystem,
but it turns we missed the O_CREAT path. Ooops.
Pavel Tikhomirov and Oleg Nesterov worked together to fix a long
standing bug in the implemenation of PR_SET_CHILD_SUBREAPER where only
children that are forked after the prctl are considered and not
children forked before the prctl. The only known user of this prctl
systemd forks all children after the prctl. So no userspace
regressions will occur. Holding earlier forked children to the same
rules as later forked children creates a semantic that is sane enough
to allow checkpoing of processes that use this feature.
There is a long delayed change by Nikolay Borisov to limit inotify
instances inside a user namespace.
Michael Kerrisk extends the API for files used to maniuplate
namespaces with two new trivial ioctls to allow discovery of the
hierachy and properties of namespaces.
Konstantin Khlebnikov with the help of Al Viro adds code that when a
network namespace exits purges it's sysctl entries from the dcache. As
in some circumstances this could use a lot of memory.
Vivek Goyal fixed a bug with stacked filesystems where the permissions
on the wrong inode were being checked.
I continue previous work on ptracing across exec. Allowing a file to
be setuid across exec while being ptraced if the tracer has enough
credentials in the user namespace, and if the process has CAP_SETUID
in it's own namespace. Proc files for setuid or otherwise undumpable
executables are now owned by the root in the user namespace of their
mm. Allowing debugging of setuid applications in containers to work
better.
A bug I introduced with permission checking and automount is now
fixed. The big change is to mark the mounts that the kernel initiates
as a result of an automount. This allows the permission checks in sget
to be safely suppressed for this kind of mount. As the permission
check happened when the original filesystem was mounted.
Finally a special case in the mount namespace is removed preventing
unbounded chains in the mount hash table, and making the semantics
simpler which benefits CRIU.
The vfs fix along with related work in ima and evm I believe makes us
ready to finish developing and merge fully unprivileged mounts of the
fuse filesystem. The cleanups of the mount namespace makes discussing
how to fix the worst case complexity of umount. The stacked filesystem
fixes pave the way for adding multiple mappings for the filesystem
uids so that efficient and safer containers can be implemented"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
proc/sysctl: Don't grab i_lock under sysctl_lock.
vfs: Use upper filesystem inode in bprm_fill_uid()
proc/sysctl: prune stale dentries during unregistering
mnt: Tuck mounts under others instead of creating shadow/side mounts.
prctl: propagate has_child_subreaper flag to every descendant
introduce the walk_process_tree() helper
nsfs: Add an ioctl() to return owner UID of a userns
fs: Better permission checking for submounts
exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction
vfs: open() with O_CREAT should not create inodes with unknown ids
nsfs: Add an ioctl() to return the namespace type
proc: Better ownership of files for non-dumpable tasks in user namespaces
exec: Remove LSM_UNSAFE_PTRACE_CAP
exec: Test the ptracer's saved cred to see if the tracee can gain caps
exec: Don't reset euid and egid when the tracee has CAP_SETUID
inotify: Convert to using per-namespace limits
Patch series "DAX tracepoints, mm argument simplification", v4.
This contains both my DAX tracepoint code and Dave Jiang's MM argument
simplifications. Dave's code was written with my tracepoint code as a
baseline, so it seemed simplest to keep them together in a single series.
This patch (of 7):
Add __print_flags_u64() and the helper trace_print_flags_seq_u64() in the
same spirit as __print_symbolic_u64() and trace_print_symbols_seq_u64().
These functions allow us to print symbols associated with flags that are
64 bits wide even on 32 bit machines.
These will be used by the DAX code so that we can print the flags set in a
pfn_t such as PFN_SG_CHAIN, PFN_SG_LAST, PFN_DEV and PFN_MAP.
Without this new function I was getting errors like the following when
compiling for i386:
include/linux/pfn_t.h:13:22: warning: large integer implicitly truncated to unsigned type [-Woverflow]
#define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1))
^
Link: http://lkml.kernel.org/r/1484085142-2297-2-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking updates from David Miller:
"Highlights:
1) Support TX_RING in AF_PACKET TPACKET_V3 mode, from Sowmini
Varadhan.
2) Simplify classifier state on sk_buff in order to shrink it a bit.
From Willem de Bruijn.
3) Introduce SIPHASH and it's usage for secure sequence numbers and
syncookies. From Jason A. Donenfeld.
4) Reduce CPU usage for ICMP replies we are going to limit or
suppress, from Jesper Dangaard Brouer.
5) Introduce Shared Memory Communications socket layer, from Ursula
Braun.
6) Add RACK loss detection and allow it to actually trigger fast
recovery instead of just assisting after other algorithms have
triggered it. From Yuchung Cheng.
7) Add xmit_more and BQL support to mvneta driver, from Simon Guinot.
8) skb_cow_data avoidance in esp4 and esp6, from Steffen Klassert.
9) Export MPLS packet stats via netlink, from Robert Shearman.
10) Significantly improve inet port bind conflict handling, especially
when an application is restarted and changes it's setting of
reuseport. From Josef Bacik.
11) Implement TX batching in vhost_net, from Jason Wang.
12) Extend the dummy device so that VF (virtual function) features,
such as configuration, can be more easily tested. From Phil
Sutter.
13) Avoid two atomic ops per page on x86 in bnx2x driver, from Eric
Dumazet.
14) Add new bpf MAP, implementing a longest prefix match trie. From
Daniel Mack.
15) Packet sample offloading support in mlxsw driver, from Yotam Gigi.
16) Add new aquantia driver, from David VomLehn.
17) Add bpf tracepoints, from Daniel Borkmann.
18) Add support for port mirroring to b53 and bcm_sf2 drivers, from
Florian Fainelli.
19) Remove custom busy polling in many drivers, it is done in the core
networking since 4.5 times. From Eric Dumazet.
20) Support XDP adjust_head in virtio_net, from John Fastabend.
21) Fix several major holes in neighbour entry confirmation, from
Julian Anastasov.
22) Add XDP support to bnxt_en driver, from Michael Chan.
23) VXLAN offloads for enic driver, from Govindarajulu Varadarajan.
24) Add IPVTAP driver (IP-VLAN based tap driver) from Sainath Grandhi.
25) Support GRO in IPSEC protocols, from Steffen Klassert"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1764 commits)
Revert "ath10k: Search SMBIOS for OEM board file extension"
net: socket: fix recvmmsg not returning error from sock_error
bnxt_en: use eth_hw_addr_random()
bpf: fix unlocking of jited image when module ronx not set
arch: add ARCH_HAS_SET_MEMORY config
net: napi_watchdog() can use napi_schedule_irqoff()
tcp: Revert "tcp: tcp_probe: use spin_lock_bh()"
net/hsr: use eth_hw_addr_random()
net: mvpp2: enable building on 64-bit platforms
net: mvpp2: switch to build_skb() in the RX path
net: mvpp2: simplify MVPP2_PRS_RI_* definitions
net: mvpp2: fix indentation of MVPP2_EXT_GLOBAL_CTRL_DEFAULT
net: mvpp2: remove unused register definitions
net: mvpp2: simplify mvpp2_bm_bufs_add()
net: mvpp2: drop useless fields in mvpp2_bm_pool and related code
net: mvpp2: remove unused 'tx_skb' field of 'struct mvpp2_tx_queue'
net: mvpp2: release reference to txq_cpu[] entry after unmapping
net: mvpp2: handle too large value in mvpp2_rx_time_coal_set()
net: mvpp2: handle too large value handling in mvpp2_rx_pkts_coal_set()
net: mvpp2: remove useless arguments in mvpp2_rx_{pkts, time}_coal_set
...
All map types and prog types are registered to the BPF core through
bpf_register_map_type() and bpf_register_prog_type() during init and
remain unchanged thereafter. As by design we don't (and never will)
have any pluggable code that can register to that at any later point
in time, lets mark all the existing bpf_{map,prog}_type_list objects
in the tree as __ro_after_init, so they can be moved to read-only
section from then onwards.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The comment about ring buffer's organization is outdated and the code sits
elsewhere, remove the comment.
Link: http://lkml.kernel.org/r/20170217041058.23904-1-joelaf@google.com
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since tracing/*probe_events will accept a probe definition
up to 4096 - 2 ('\n' and '\0') bytes, it must show 4094 instead
of 4096 in warning message.
Note that there is one possible case of exceed 4094. If user
prepare 4096 bytes null-terminated string and syscall write
it with the count == 4095, then it can be accepted. However,
if user puts a '\n' after that, it must rejected.
So IMHO, the warning message should indicate shorter one,
since it is safer.
Link: http://lkml.kernel.org/r/148673290462.2579.7966778294009665632.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In case of error, the function kthread_run() returns ERR_PTR() and never
returns NULL. The NULL test in the return value check should be replaced
with IS_ERR().
Link: http://lkml.kernel.org/r/20170112135502.28556-1-weiyj.lk@gmail.com
Cc: stable@vger.kernel.org
Fixes: 81dc9f0e ("tracing: Add tracepoint benchmark tracepoint")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
We get a lot of harmless warnings about this header file at W=1 level
because of an unusual function declaration:
kernel/trace/trace.h:766:1: error: 'inline' is not at beginning of declaration [-Werror=old-style-declaration]
This moves the inline statement where it normally belongs, avoiding the
warning.
Link: http://lkml.kernel.org/r/20170123122521.3389010-1-arnd@arndb.de
Fixes: 4046bf023b ("ftrace: Expose ftrace_hash_empty and ftrace_lookup_ip")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Show "trace_probe:", "trace_kprobe:" and "trace_uprobe:"
headers for each warning/error/info message. This will
help people to notice that kprobe/uprobe events caused
those messages.
Link: http://lkml.kernel.org/r/148646647813.24658.16705315294927615333.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The code in traceprobe_probes_write() reads up to 4096 bytes from userpace
for each line. If userspace passes in several lines to execute, the code
will do a large read for each line, even though, it is highly likely that
the first read from userspace received all of the lines at once.
I changed the logic to do a single read from userspace, and to only read
from userspace again if not all of the read from userspace made it in.
I tested this by adding printk()s and writing files that would test -1, ==,
and +1 the buffer size, to make sure that there's no overflows and that if a
single line is written with +1 the buffer size, that it fails properly.
Link: http://lkml.kernel.org/r/20170209180458.5c829ab2@gandalf.local.home
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The GLOB operation "~" should be able to work with the COMM filter key in
order to trace programs with a glob. For example
echo 'COMM ~ "systemd*"' > events/syscalls/filter
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The conflict was an interaction between a bug fix in the
netvsc driver in 'net' and an optimization of the RX path
in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Steven suggested to improve trace_print_hex_seq() a bit after commit
2acae0d5b0 ("trace: add variant without spacing in trace_print_hex_seq")
in two ways: i) by adding a kdoc comment for the helper function
itself and ii) by renaming 'spacing' argument into 'concatenate'
to better denote that we don't add spaces between each hex bytes.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, only one function can be written to set_graph_function and
set_graph_notrace. The last function in the list will have saved, even
though other functions will be added then removed.
Change the behavior to be the same as set_ftrace_function as to allow
multiple functions to be written. If any one fails, none of them will be
added. The addition of the functions are done at the end when the file is
closed.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The hashs ftrace_graph_hash and ftrace_graph_notrace_hash are modified
within the graph_lock being held. Holding a pointer to them and passing them
along can lead to a use of a stale pointer (fgd->hash). Move assigning the
pointer and its use to within the holding of the lock. Note, it's an
rcu_sched protected data, and other instances of referencing them are done
with preemption disabled. But the file manipuation code must be protected by
the lock.
The fgd->hash pointer is set to NULL when the lock is being released.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
trace_parser_put() simply frees the allocated parser buffer. But it does not
reset the pointer that was freed. This means that if trace_parser_put() is
called on the same parser more than once, it will corrupt the allocation
system. Setting parser->buffer to NULL after free allows it to be called
more than once without any ill effect.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since reading the set_graph_functions uses seq functions, which sets the
file->private_data pointer to a seq_file descriptor. On writes the
ftrace_graph_data descriptor is set to file->private_data. But if the file
is opened for RDWR, the ftrace_graph_write() will incorrectly use the
file->private_data descriptor instead of
((struct seq_file *)file->private_data)->private pointer, and this can crash
the kernel.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When the set_graph_function or set_graph_notrace contains no records, a
banner is displayed of either "#### all functions enabled ####" or
"#### all functions disabled ####" respectively. To tell the seq operations
to do this, (void *)1 is passed as a return value. Instead of using a
hardcoded meaningless variable, define it as a macro.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This is a micro-optimization, but as it has to deal with a fast path of the
function tracer, these optimizations can be noticed.
The ftrace_lookup_ip() returns true if the given ip is found in the hash. If
it's not found or the hash is NULL, it returns false. But there's some cases
that a NULL hash is a true, and the ftrace_hash_empty() is tested before
calling ftrace_lookup_ip() in those cases. But as ftrace_lookup_ip() tests
that first, that adds a few extra unneeded instructions in those cases.
A new static "always_inlined" function is created that does not perform the
hash empty test. This most only be used by callers that do the check first
anyway, as an empty or NULL hash could cause a crash if a lookup is
performed on it.
Also add kernel doc for the ftrace_lookup_ip() main function.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Replace the couple of use cases that has small logic to produce the ftrace
function key id with a helper function. No need for duplicate code.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
We may already have a directory to put the blktrace stuff in if
1. The disk uses blk-mq
2. CONFIG_BLK_DEBUG_FS is enabled
3. We are tracing the whole disk and not a partition
Instead of hardcoding this very specific case, let's use the new
debugfs_lookup(). If the directory exists, we use it, otherwise we
create one and clean it up later.
Fixes: 07e4fead45 ("blk-mq: create debugfs directory tree")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
When I added the blk-mq debugging information to debugfs, I didn't
notice that blktrace also creates a "block" directory in debugfs. Make
them use the same dentry, now created in the core block code. Based on a
patch from Jens.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
clang complains about "__init" being attached to a struct name:
kernel/trace/trace_kprobe.c:1375:15: error: '__section__' attribute only applies to functions and global variables
The intention must have been to mark the function as __init instead of
the type, so move the attribute there.
Link: http://lkml.kernel.org/r/20170201165826.2625888-1-arnd@arndb.de
Fixes: f18f97ac43 ("tracing/kprobes: Add a helper method to return number of probe hits")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
To support unprivileged users mounting filesystems two permission
checks have to be performed: a test to see if the user allowed to
create a mount in the mount namespace, and a test to see if
the user is allowed to access the specified filesystem.
The automount case is special in that mounting the original filesystem
grants permission to mount the sub-filesystems, to any user who
happens to stumble across the their mountpoint and satisfies the
ordinary filesystem permission checks.
Attempting to handle the automount case by using override_creds
almost works. It preserves the idea that permission to mount
the original filesystem is permission to mount the sub-filesystem.
Unfortunately using override_creds messes up the filesystems
ordinary permission checks.
Solve this by being explicit that a mount is a submount by introducing
vfs_submount, and using it where appropriate.
vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let
sget and friends know that a mount is a submount so they can take appropriate
action.
sget and sget_userns are modified to not perform any permission checks
on submounts.
follow_automount is modified to stop using override_creds as that
has proven problemantic.
do_mount is modified to always remove the new MS_SUBMOUNT flag so
that we know userspace will never by able to specify it.
autofs4 is modified to stop using current_real_cred that was put in
there to handle the previous version of submount permission checking.
cifs is modified to pass the mountpoint all of the way down to vfs_submount.
debugfs is modified to pass the mountpoint all of the way down to
trace_automount by adding a new parameter. To make this change easier
a new typedef debugfs_automount_t is introduced to capture the type of
the debugfs automount function.
Cc: stable@vger.kernel.org
Fixes: 069d5ac9ae ("autofs: Fix automounts by using current_real_cred()->uid")
Fixes: aeaa4a79ff ("fs: Call d_automount with the filesystems creds")
Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Instead of initializing the affinity of the hwlat kthread in the thread
itself, simply set up the initial affinity at thread creation. This
simplifies the code.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This can be used to check for fs vs non-fs requests and basically
removes all knowledge of BLOCK_PC specific from the block layer,
as well as preparing for removing the cmd_type field in struct request.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The hwlat tracer creates a kernel thread at start of the tracer. It is
pinned to a single CPU and will move to the next CPU after each period of
running. If the user modifies the migration thread's affinity, it will not
change after that happens.
The original code created the thread at the first instance it was called,
but later was changed to destroy the thread after the tracer was finished,
and would not be created until the next instance of the tracer was
established. The code that initialized the affinity was only called on the
initial instantiation of the tracer. After that, it was not initialized, and
the previous affinity did not match the current newly created one, making
it appear that the user modified the thread's affinity when it did not, and
the thread failed to migrate again.
Cc: stable@vger.kernel.org
Fixes: 0330f7aa8e ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
A couple tweaks to the tracing code:
- trace the request size for all requests
- trace request sector and nr_sectors only for fs requests, enforced by
helpers
- drop SCSI CDB tracing - we have SCSI tracing for this and are going
to me the CDB out of the generic struct request soon.
With this the tracing code stops to know about BLOCK_PC requests entirely,
it's just FS vs passthrough requests now, where the latter includes any
driver-private requests.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
For upcoming tracepoint support for BPF, we want to dump the program's
tag. Format should be similar to __print_hex(), but without spacing.
Add a __print_hex_str() variant for exactly that purpose that reuses
trace_print_hex_seq().
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use ftrace_hash instead of a static array of a fixed size. This is
useful when a graph filter pattern matches to a large number of
functions. Now hash lookup is done with preemption disabled to protect
from the hash being changed/freed.
Link: http://lkml.kernel.org/r/20170120024447.26097-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
It will be used when checking graph filter hashes later.
Link: http://lkml.kernel.org/r/20170120024447.26097-2-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
[ Moved ftrace_hash dec and functions outside of FUNCTION_GRAPH define ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Provide a simple helper with the same semantics of strncpy_from_unsafe():
int bpf_probe_read_str(void *dst, int size, const void *unsafe_addr)
This gives more flexibility to a bpf program. A typical use case is
intercepting a file name during sys_open(). The current approach is:
SEC("kprobe/sys_open")
void bpf_sys_open(struct pt_regs *ctx)
{
char buf[PATHLEN]; // PATHLEN is defined to 256
bpf_probe_read(buf, sizeof(buf), ctx->di);
/* consume buf */
}
This is suboptimal because the size of the string needs to be estimated
at compile time, causing more memory to be copied than often necessary,
and can become more problematic if further processing on buf is done,
for example by pushing it to userspace via bpf_perf_event_output(),
since the real length of the string is unknown and the entire buffer
must be copied (and defining an unrolled strnlen() inside the bpf
program is a very inefficient and unfeasible approach).
With the new helper, the code can easily operate on the actual string
length rather than the buffer size:
SEC("kprobe/sys_open")
void bpf_sys_open(struct pt_regs *ctx)
{
char buf[PATHLEN]; // PATHLEN is defined to 256
int res = bpf_probe_read_str(buf, sizeof(buf), ctx->di);
/* consume buf, for example push it to userspace via
* bpf_perf_event_output(), but this time we can use
* res (the string length) as event size, after checking
* its boundaries.
*/
}
Another useful use case is when parsing individual process arguments or
individual environment variables navigating current->mm->arg_start and
current->mm->env_start: using this helper and the return value, one can
quickly iterate at the right offset of the memory area.
The code changes simply leverage the already existent
strncpy_from_unsafe() kernel function, which is safe to be called from a
bpf program as it is used in bpf_trace_printk().
Signed-off-by: Gianluca Borello <g.borello@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The __ftrace_hash_move() is to allocates properly-sized hash and move
entries in the src ftrace_hash. It will be used to set function graph
filters which has nothing to do with the dyn_ftrace records.
Link: http://lkml.kernel.org/r/20170120024447.26097-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The unlikely/likely branch profiler now gets called even if the if statement
is a constant (always goes in one direction without a compare). Add a value
to denote this in the likely/unlikely tracer as well.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Now that constants are traced, it is useful to see the number of constants
that are traced in the likely/unlikely profiler in order to know if they
should be ignored or not.
The likely/unlikely will display a number after the "correct" number if a
"constant" count exists.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When running the likely/unlikely profiler, one of the results did not look
accurate. It noted that the unlikely() in link_path_walk() was 100%
incorrect. When I added a trace_printk() to see what was happening there, it
became 80% correct! Looking deeper into what whas happening, I found that
gcc split that if statement into two paths. One where the if statement
became a constant, the other path a variable. The other path had the if
statement always hit (making the unlikely there, always false), but since
the #define unlikely() has:
#define unlikely() (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
Where constants are ignored by the branch profiler, the "constant" path
made by the compiler was ignored, even though it was hit 80% of the time.
By just passing the constant value to the __branch_check__() function and
tracing it out of line (as always correct, as likely/unlikely isn't a factor
for constants), then we get back the accurate readings of branches that were
optimized by gcc causing part of the execution to become constant.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Previously, `create_trace_uprobe` found the *first* occurence
of the ':' character when parsing `PATH:OFFSET` for a uprobe.
However, if the path contains a ':' character, then the function
would parse the path incorrectly. Even worse, if the path does not
exist, the subsequent call to `kern_path()` would set `ret` to
`ENOENT`, leading to very cryptic errno values in user space.
The fix is to find the *last* occurence of ':'.
How to repro:: The write fails with "No such file or directory", suggesting
incorrectly that the `uprobe_events` file does not exist.
$ mkdir testing && cd testing
$ cp /bin/bash .
$ cp /bin/bash ./bash:with:colon
$ echo "p:uprobes/p__root_testing_bash_0x6 /root/testing/bash:0x6" > /sys/kernel/debug/tracing/uprobe_events # this works
$ echo "p:uprobes/p__root_testing_bash_with_colon_0x6 /root/testing/bash:with:colon:0x6" >> /sys/kernel/debug/tracing/uprobe_events # this doesn't
-bash: echo: write error: No such file or directory
With the patch:
$ echo "p:uprobes/p__root_testing_bash_0x6 /root/testing/bash:0x6" > /sys/kernel/debug/tracing/uprobe_events # this still works
$ echo "p:uprobes/p__root_testing_bash_with_colon_0x6 /root/testing/bash:with:colon:0x6" >> /sys/kernel/debug/tracing/uprobe_events # this works now too!
$ cat /sys/kernel/debug/tracing/uprobe_events
p:uprobes/p__root_testing_bash_0x6 /root/testing/bash:0x0000000000000006
p:uprobes/p__root_testing_bash_with_colon_0x6 /root/testing/bash:with:colon:0x0000000000000006
Link: http://lkml.kernel.org/r/20170113165834.4081016-1-kennyyu@fb.com
Signed-off-by: Kenny Yu <kennyyu@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Make sure that ctx cannot potentially be accessed oob by asserting
explicitly that ctx access size into pt_regs for BPF_PROG_TYPE_KPROBE
programs must be within limits. In case some 32bit archs have pt_regs
not being a multiple of 8, then BPF_DW access could cause such access.
BPF_PROG_TYPE_KPROBE progs don't have a ctx conversion function since
there's no extra mapping needed. kprobe_prog_is_valid_access() didn't
enforce sizeof(long) as the only allowed access size, since LLVM can
generate non BPF_W/BPF_DW access to regs from time to time.
For BPF_PROG_TYPE_TRACEPOINT we don't have a ctx conversion either, so
add a BUILD_BUG_ON() check to make sure that BPF_DW access will not be
a similar issue in future (ctx works on event buffer as opposed to
pt_regs there).
Fixes: 2541517c32 ("tracing, perf: Implement BPF programs attached to kprobes")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, when calling convert_ctx_access() callback for the various
program types, we pass in insn->dst_reg, insn->src_reg, insn->off from
the original instruction. This information is needed to rewrite the
instruction that is based on the user ctx structure into a kernel
representation for the ctx. As we'd like to allow access size beyond
just BPF_W, we'd need also insn->code for that in order to decode the
original access size. Given that, lets just pass insn directly to the
convert_ctx_access() callback and work on that to not clutter the
callback with even more arguments we need to pass when everything is
already contained in insn. So lets go through that once, no functional
change.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
since ARG_PTR_TO_STACK is no longer just pointer to stack
rename it to ARG_PTR_TO_MEM and adjust comment.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller