perf probe: Improve detection of file/function name in the probe pattern

Currently, perf probe considers patterns including a '.' to be a file.
However, this causes problems on powerpc ABIv1 where all functions have
a leading '.':

  $ perf probe -F | grep schedule_timeout_interruptible
  .schedule_timeout_interruptible
  $ perf probe .schedule_timeout_interruptible
  Semantic error :File always requires line number or lazy pattern.
    Error: Command Parse Error.

Fix this:
- by checking the probe pattern in more detail, and
- skipping leading dot if one exists when creating/deleting events.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/db680f7cb11c4452b632f908e67151f3aa0f4602.1430217967.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index eb75a5e..416c10f 100644 (file)
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1077,6 +1077,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
        struct perf_probe_point *pp = &pev->point;
        char *ptr, *tmp;
        char c, nc = 0;
+       bool file_spec = false;
        /*
         * <Syntax>
         * perf probe [EVENT=]SRC[:LN|;PTN]
@@ -1105,6 +1106,23 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
                arg = tmp;
        }
 
+       /*
+        * Check arg is function or file name and copy it.
+        *
+        * We consider arg to be a file spec if and only if it satisfies
+        * all of the below criteria::
+        * - it does not include any of "+@%",
+        * - it includes one of ":;", and
+        * - it has a period '.' in the name.
+        *
+        * Otherwise, we consider arg to be a function specification.
+        */
+       if (!strpbrk(arg, "+@%") && (ptr = strpbrk(arg, ";:")) != NULL) {
+               /* This is a file spec if it includes a '.' before ; or : */
+               if (memchr(arg, '.', ptr - arg))
+                       file_spec = true;
+       }
+
        ptr = strpbrk(arg, ";:+@%");
        if (ptr) {
                nc = *ptr;
@@ -1115,10 +1133,9 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
        if (tmp == NULL)
                return -ENOMEM;
 
-       /* Check arg is function or file and copy it */
-       if (strchr(tmp, '.'))   /* File */
+       if (file_spec)
                pp->file = tmp;
-       else                    /* Function */
+       else
                pp->function = tmp;
 
        /* Parse other options */
@@ -2265,6 +2282,9 @@ static int get_new_event_name(char *buf, size_t len, const char *base,
 {
        int i, ret;
 
+       if (*base == '.')
+               base++;
+
        /* Try no suffix */
        ret = e_snprintf(buf, len, "%s", base);
        if (ret < 0) {
@@ -2766,6 +2786,9 @@ int del_perf_probe_events(struct strlist *dellist)
                        event = str;
                }
 
+               if (event && *event == '.')
+                       event++;
+
                ret = e_snprintf(buf, 128, "%s:%s", group, event);
                if (ret < 0) {
                        pr_err("Failed to copy event.");