linux/kernel/trace
Frederic Weisbecker eae849ca03 tracing/function-return-tracer: don't trace kfree while it frees the return stack
Impact: fix a crash

While I killed the cat process, I got sometimes the following (but rare)
crash:

[   65.689027] Pid: 2969, comm: cat Not tainted (2.6.28-rc6-tip #83) AMILO Li 2727
[   65.689027] EIP: 0060:[<00000000>] EFLAGS: 00010082 CPU: 1
[   65.689027] EIP is at 0x0
[   65.689027] EAX: 00000000 EBX: f66cd780 ECX: c019a64a EDX: f66cd780
[   65.689027] ESI: 00000286 EDI: f66cd780 EBP: f630be2c ESP: f630be24
[   65.689027]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[   65.689027] Process cat (pid: 2969, ti=f630a000 task=f66cd780 task.ti=f630a000)
[   65.689027] Stack:
[   65.689027]  00000012 f630bd54 f630be7c c012c853 00000000 c0133cc9 f66cda54 f630be5c
[   65.689027]  f630be68 f66cda54 f66cd88c f66cd878 f7070000 00000001 f630be90 c0135dbc
[   65.689027]  f614a614 f630be68 f630be68 f65ba200 00000002 f630bf10 f630be90 c012cad6
[   65.689027] Call Trace:
[   65.689027]  [<c012c853>] ? do_exit+0x603/0x850
[   65.689027]  [<c0133cc9>] ? next_signal+0x9/0x40
[   65.689027]  [<c0135dbc>] ? dequeue_signal+0x8c/0x180
[   65.689027]  [<c012cad6>] ? do_group_exit+0x36/0x90
[   65.689027]  [<c013709c>] ? get_signal_to_deliver+0x20c/0x390
[   65.689027]  [<c0102b69>] ? do_notify_resume+0x99/0x8b0
[   65.689027]  [<c02e6d1a>] ? tty_ldisc_deref+0x5a/0x80
[   65.689027]  [<c014db9b>] ? trace_hardirqs_on+0xb/0x10
[   65.689027]  [<c02e6d1a>] ? tty_ldisc_deref+0x5a/0x80
[   65.689027]  [<c02e39b0>] ? n_tty_write+0x0/0x340
[   65.689027]  [<c02e1812>] ? redirected_tty_write+0x82/0x90
[   65.689027]  [<c019ee99>] ? vfs_write+0x99/0xd0
[   65.689027]  [<c02e1790>] ? redirected_tty_write+0x0/0x90
[   65.689027]  [<c019f342>] ? sys_write+0x42/0x70
[   65.689027]  [<c01035ca>] ? work_notifysig+0x13/0x19
[   65.689027] Code:  Bad EIP value.
[   65.689027] EIP: [<00000000>] 0x0 SS:ESP 0068:f630be24

This is because on do_exit(), kfree is called to free the return addresses stack
but kfree is traced and stored its return address in this stack.
This patch fixes it.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23 17:39:03 +01:00
..
ftrace.c tracing/function-return-tracer: don't trace kfree while it frees the return stack 2008-11-23 17:39:03 +01:00
Kconfig tracing/function-return-tracer: support for dynamic ftrace on function return tracer 2008-11-16 07:57:38 +01:00
Makefile ftrace: rename trace_unlikely.c file 2008-11-12 22:28:40 +01:00
ring_buffer.c Merge branches 'tracing/ftrace' and 'tracing/urgent' into tracing/core 2008-11-19 10:04:25 +01:00
trace_boot.c tracing/ftrace: change the type of the init() callback 2008-11-16 07:55:23 +01:00
trace_branch.c Merge branches 'tracing/branch-tracer', 'tracing/ftrace', 'tracing/function-return-tracer', 'tracing/tracepoints' and 'tracing/urgent' into tracing/core 2008-11-17 09:36:22 +01:00
trace_functions_return.c tracing/function-return-tracer: add the overrun field 2008-11-18 11:11:00 +01:00
trace_functions.c tracing/ftrace: change the type of the init() callback 2008-11-16 07:55:23 +01:00
trace_irqsoff.c tracing/ftrace: change the type of the init() callback 2008-11-16 07:55:23 +01:00
trace_mmiotrace.c tracing/ftrace: change the type of the init() callback 2008-11-16 07:55:23 +01:00
trace_nop.c tracing/ftrace: make nop tracer using tracer flags 2008-11-18 11:10:59 +01:00
trace_sched_switch.c tracing/ftrace: change the type of the init() callback 2008-11-16 07:55:23 +01:00
trace_sched_wakeup.c tracing/ftrace: change the type of the init() callback 2008-11-16 07:55:23 +01:00
trace_selftest_dynamic.c ftrace: fix dynamic ftrace selftest 2008-05-23 21:13:23 +02:00
trace_selftest.c tracing/ftrace: change the type of the init() callback 2008-11-16 07:55:23 +01:00
trace_stack.c Merge branches 'tracing/profiling', 'tracing/options' and 'tracing/urgent' into tracing/core 2008-11-23 09:10:32 +01:00
trace_sysprof.c tracing/ftrace: change the type of the init() callback 2008-11-16 07:55:23 +01:00
trace.c Merge branches 'tracing/profiling', 'tracing/options' and 'tracing/urgent' into tracing/core 2008-11-23 09:10:32 +01:00
trace.h tracing/function-return-tracer: add the overrun field 2008-11-18 11:11:00 +01:00