linux/kernel/trace
Török Edwin b54d3de9f3 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>
2008-11-23 09:45:42 +01:00
..
ftrace.c Merge branch 'tip/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/urgent 2008-11-19 09:00:50 +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 tracing: identify which executable object the userspace address belongs to 2008-11-23 09:45:42 +01:00
trace.h tracing: identify which executable object the userspace address belongs to 2008-11-23 09:45:42 +01:00