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  1. 08 3月, 2018 15 次提交
  3. 14 2月, 2018 1 次提交
  5. 22 12月, 2017 1 次提交
  7. 06 11月, 2017 1 次提交
  9. 20 10月, 2017 2 次提交
  11. 25 8月, 2017 1 次提交
  13. 12 7月, 2017 1 次提交
  15. 22 6月, 2017 1 次提交
  17. 09 6月, 2017 1 次提交
  19. 04 4月, 2017 1 次提交
    • A
      tracing/kprobes: expose maxactive for kretprobe in kprobe_events · 696ced4f
      由 Alban Crequy 提交于 
      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.ioAcked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NAlban Crequy <alban@kinvolk.io>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      696ced4f
  21. 24 3月, 2017 1 次提交
  23. 15 3月, 2017 1 次提交
  25. 01 3月, 2017 1 次提交
  27. 23 2月, 2017 1 次提交
  29. 30 11月, 2016 1 次提交
  31. 18 11月, 2016 3 次提交
  33. 16 11月, 2016 1 次提交
  35. 15 11月, 2016 1 次提交
  37. 22 10月, 2016 1 次提交
  39. 03 9月, 2016 2 次提交
  41. 02 9月, 2016 1 次提交
  43. 24 8月, 2016 1 次提交
    • J
      ftrace: Add return address pointer to ftrace_ret_stack · 9a7c348b
      由 Josh Poimboeuf 提交于 
      Storing this value will help prevent unwinders from getting out of sync
with the function graph tracer ret_stack.  Now instead of needing a
stateful iterator, they can compare the return address pointer to find
the right ret_stack entry.

Note that an array of 50 ftrace_ret_stack structs is allocated for every
task.  So when an arch implements this, it will add either 200 or 400
bytes of memory usage per task (depending on whether it's a 32-bit or
64-bit platform).
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a95cfcc39e8f26b89a430c56926af0bb217bc0a1.1471607358.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      9a7c348b