tracing/kprobes: Support module init function probing

To support probing module init functions, kprobe-tracer allows
user to define a probe on non-existed function when it is given
with a module name. This also enables user to set a probe on
a function on a specific module, even if a same name (but different)
function is locally defined in another module.

The module name must be in the front of function name and separated
by a ':'. e.g. btrfs:btrfs_init_sysfs

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/20110627072656.6528.89970.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index c83bd6b4e6e8..d0d0bb9e3e25 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -22,14 +22,15 @@ current_tracer. Instead of that, add probe points via
 
 Synopsis of kprobe_events
 -------------------------
-  p[:[GRP/]EVENT] SYMBOL[+offs]|MEMADDR [FETCHARGS]     : Set a probe
-  r[:[GRP/]EVENT] SYMBOL[+0] [FETCHARGS]                : Set a return probe
+  p[:[GRP/]EVENT] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS]  : Set a probe
+  r[:[GRP/]EVENT] [MOD:]SYM[+0] [FETCHARGS]             : Set a return probe
   -:[GRP/]EVENT                                         : Clear a probe
 
  GRP            : Group name. If omitted, use "kprobes" for it.
  EVENT          : Event name. If omitted, the event name is generated
-                  based on SYMBOL+offs or MEMADDR.
- SYMBOL[+offs]  : Symbol+offset where the probe is inserted.
+                  based on SYM+offs or MEMADDR.
+ MOD            : Module name which has given SYM.
+ SYM[+offs]     : Symbol+offset where the probe is inserted.
  MEMADDR        : Address where the probe is inserted.
 
  FETCHARGS      : Arguments. Each probe can have up to 128 args.