diff options
| author | Török Edwin <edwintorok@gmail.com> | 2008-11-22 13:28:48 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-23 09:45:42 +0100 |
| commit | b54d3de9f3b8956653b06f1a32e9f9321c6d9027 (patch) | |
| tree | fef98e07a9327371304811191cafebdd65311502 /kernel/trace/trace.h | |
| parent | 74e2f334f4440cbcb63e9ebbcdcea430d41bdfa3 (diff) | |
| download | talos-obmc-linux-b54d3de9f3b8956653b06f1a32e9f9321c6d9027.tar.gz talos-obmc-linux-b54d3de9f3b8956653b06f1a32e9f9321c6d9027.zip | |
tracing: identify which executable object the userspace address belongs to
Impact: modify+improve the userstacktrace tracing visualization feature
Store thread group leader id, and use it to lookup the address in the
process's map. We could have looked up the address on thread's map,
but the thread might not exist by the time we are called. The process
might not exist either, but if you are reading trace_pipe, that is
unlikely.
Example usage:
mount -t debugfs nodev /sys/kernel/debug
cd /sys/kernel/debug/tracing
echo userstacktrace >iter_ctrl
echo sym-userobj >iter_ctrl
echo sched_switch >current_tracer
echo 1 >tracing_enabled
cat trace_pipe >/tmp/trace&
.... run application ...
echo 0 >tracing_enabled
cat /tmp/trace
You'll see stack entries like:
/lib/libpthread-2.7.so[+0xd370]
You can convert them to function/line using:
addr2line -fie /lib/libpthread-2.7.so 0xd370
Or:
addr2line -fie /usr/lib/debug/libpthread-2.7.so 0xd370
For non-PIC/PIE executables this won't work:
a.out[+0x73b]
You need to run the following: addr2line -fie a.out 0x40073b
(where 0x400000 is the default load address of a.out)
Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/trace.h')
| -rw-r--r-- | kernel/trace/trace.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 17bb4c830b01..28c15c2ebc22 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -508,7 +508,8 @@ enum trace_iterator_flags { TRACE_ITER_PREEMPTONLY = 0x800, TRACE_ITER_BRANCH = 0x1000, TRACE_ITER_ANNOTATE = 0x2000, - TRACE_ITER_USERSTACKTRACE = 0x4000 + TRACE_ITER_USERSTACKTRACE = 0x4000, + TRACE_ITER_SYM_USEROBJ = 0x8000 }; /* |
