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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2018-04-25 21:21:26 +0900 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-10-10 22:19:11 -0400 |
| commit | a1303af5d79eb13a658633a9fb0ce3aed0f7decf (patch) | |
| tree | 06ab7627ff3bec7afcba894432a5798babd3e0bc /kernel/trace/trace.c | |
| parent | 3c88ee194c288205733d248b51f0aca516ff4940 (diff) | |
| download | linux-a1303af5d79eb13a658633a9fb0ce3aed0f7decf.tar.bz2 | |
tracing: probeevent: Add $argN for accessing function args
Add $argN special fetch variable for accessing function
arguments. This allows user to trace the Nth argument easily
at the function entry.
Note that this returns most probably assignment of registers
and stacks. In some case, it may not work well. If you need
to access correct registers or stacks you should use perf-probe.
Link: http://lkml.kernel.org/r/152465888632.26224.3412465701570253696.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e7f99f513959..ec5b21778806 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4625,7 +4625,11 @@ static const char readme_msg[] = #endif "\t args: <name>=fetcharg[:type]\n" "\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n" +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API + "\t $stack<index>, $stack, $retval, $comm, $arg<N>\n" +#else "\t $stack<index>, $stack, $retval, $comm\n" +#endif "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" "\t b<bit-width>@<bit-offset>/<container-size>,\n" "\t <type>\\[<array-size>\\]\n" |