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| author | Omar Sandoval <osandov@fb.com> | 2016-06-08 18:38:02 -0700 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2016-06-20 09:54:19 -0400 |
| commit | 35abb67de744b5dbaec54381f2f9e0246089331d (patch) | |
| tree | be334f88bb9cdf78b7f2fd33529469ac352c179e /Documentation/trace | |
| parent | 345ddcc882d8896dcbdcb3e0ee4a415fc23ec8b0 (diff) | |
| download | talos-obmc-linux-35abb67de744b5dbaec54381f2f9e0246089331d.tar.gz talos-obmc-linux-35abb67de744b5dbaec54381f2f9e0246089331d.zip | |
tracing: expose current->comm to [ku]probe events
ftrace is very quick to give up on saving the task command line (see
`trace_save_cmdline()`). The workaround for events which really care
about the command line is to explicitly assign it as part of the entry.
However, this doesn't work for kprobe events, as there's no
straightforward way to get access to current->comm. Add a kprobe/uprobe
event variable $comm which provides exactly that.
Link: http://lkml.kernel.org/r/f59b472033b943a370f5f48d0af37698f409108f.1465435894.git.osandov@fb.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/kprobetrace.txt | 3 | ||||
| -rw-r--r-- | Documentation/trace/uprobetracer.txt | 3 |
2 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index d68ea5fc812b..ea52ec1f8484 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -40,6 +40,7 @@ Synopsis of kprobe_events $stackN : Fetch Nth entry of stack (N >= 0) $stack : Fetch stack address. $retval : Fetch return value.(*) + $comm : Fetch current task comm. +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**) NAME=FETCHARG : Set NAME as the argument name of FETCHARG. FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types @@ -62,6 +63,8 @@ offset, and container-size (usually 32). The syntax is; b<bit-width>@<bit-offset>/<container-size> +For $comm, the default type is "string"; any other type is invalid. + Per-Probe Event Filtering ------------------------- diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt index f1cf9a34ad9d..72d1cd4f7bf3 100644 --- a/Documentation/trace/uprobetracer.txt +++ b/Documentation/trace/uprobetracer.txt @@ -36,6 +36,7 @@ Synopsis of uprobe_tracer $stackN : Fetch Nth entry of stack (N >= 0) $stack : Fetch stack address. $retval : Fetch return value.(*) + $comm : Fetch current task comm. +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**) NAME=FETCHARG : Set NAME as the argument name of FETCHARG. FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types @@ -57,6 +58,8 @@ offset, and container-size (usually 32). The syntax is; b<bit-width>@<bit-offset>/<container-size> +For $comm, the default type is "string"; any other type is invalid. + Event Profiling --------------- |
