perf probe: Support a special SDT probe format

Support a special SDT probe format which can omit the '%' prefix only if
the SDT group name starts with "sdt_". So, for example both of
"%sdt_libc:setjump" and "sdt_libc:setjump" are acceptable for perf probe
--add.

E.g. without this:

  # perf probe -a sdt_libc:setjmp
  Semantic error :There is non-digit char in line number.
  ...

With this:

  # perf probe -a sdt_libc:setjmp
  Added new event:
    sdt_libc:setjmp      (on %setjmp in /usr/lib64/libc-2.20.so)

  You can now use it in all perf tools, such as:

  	perf record -e sdt_libc:setjmp -aR sleep 1

Suggested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831794674.17065.13359473252168740430.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index 39e387042098d4c70a1ea2c6555784e6839ffaff..736da44596e451fa1a14d9a045f7feda269a0779 100644 (file)
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -152,7 +152,9 @@ Probe points are defined by following syntax.
      [[GROUP:]EVENT=]SRC;PTN [ARG ...]
 
     4) Pre-defined SDT events or cached event with name
-     %[PROVIDER:]SDTEVENT
+     %[sdt_PROVIDER:]SDTEVENT
+     or,
+     sdt_PROVIDER:SDTEVENT
 
 'EVENT' specifies the name of new event, if omitted, it will be set the name of the probed function. You can also specify a group name by 'GROUP', if omitted, set 'probe' is used for kprobe and 'probe_<bin>' is used for uprobe.
 Note that using existing group name can conflict with other events. Especially, using the group name reserved for kernel modules can hide embedded events in the

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index f12081e48a3263b73cbc1fb3357887a2332aa48b..d4f8835c0a279107ca428d77ffe19cba6f8bde48 100644 (file)
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1243,9 +1243,17 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
        if (!arg)
                return -EINVAL;
 
-       if (arg[0] == '%') {
+       /*
+        * If the probe point starts with '%',
+        * or starts with "sdt_" and has a ':' but no '=',
+        * then it should be a SDT/cached probe point.
+        */
+       if (arg[0] == '%' ||
+           (!strncmp(arg, "sdt_", 4) &&
+            !!strchr(arg, ':') && !strchr(arg, '='))) {
                pev->sdt = true;
-               arg++;
+               if (arg[0] == '%')
+                       arg++;
        }
 
        ptr = strpbrk(arg, ";=@+%");