perf probe: Support event name for --add option

Support event name syntax for --add option. This allows
users to specify event name for each new event.

The --add syntax is:
 perf probe --add '[EVENT=]SRC:LINE ARGS'
or
 perf probe --add '[EVENT=]FUNC[+OFFS|%return|:RLN][@SRC] ARGS'

e.g.

 ./perf probe --add myprobe1=schedule

Note: currently group name is not supported yet, because it
can cause name-space confliction with other tracepoint/
hw-breakpoint events.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091215153218.17436.84675.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 49 insertions, 31 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 5e99e52b0179..3b4cf456165c 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -69,10 +69,23 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
         char c, nc = 0;
         /*
          * <Syntax>
-         * perf probe SRC:LN
-         * perf probe FUNC[+OFFS|%return][@SRC]
+         * perf probe [EVENT=]SRC:LN
+         * perf probe [EVENT=]FUNC[+OFFS|%return][@SRC]
+         *
+         * TODO:Group name support
          */
 
+        ptr = strchr(arg, '=');
+        if (ptr) {      /* Event name */
+                *ptr = '\0';
+                tmp = ptr + 1;
+                ptr = strchr(arg, ':');
+                if (ptr)        /* Group name is not supported yet. */
+                        semantic_error("Group name is not supported yet.");
+                pp->event = strdup(arg);
+                arg = tmp;
+        }
+
         ptr = strpbrk(arg, ":+@%");
         if (ptr) {
                 nc = *ptr;
@@ -188,8 +201,7 @@ void parse_perf_probe_event(const char *str, struct probe_point *pp,
 }
 
 /* Parse kprobe_events event into struct probe_point */
-void parse_trace_kprobe_event(const char *str, char **group, char **event,
-                              struct probe_point *pp)
+void parse_trace_kprobe_event(const char *str, struct probe_point *pp)
 {
         char pr;
         char *p;
@@ -205,18 +217,17 @@ void parse_trace_kprobe_event(const char *str, char **group, char **event,
 
         /* Scan event and group name. */
         ret = sscanf(argv[0], "%c:%a[^/ \t]/%a[^ \t]",
-                     &pr, (float *)(void *)group, (float *)(void *)event);
+                     &pr, (float *)(void *)&pp->group,
+                     (float *)(void *)&pp->event);
         if (ret != 3)
                 semantic_error("Failed to parse event name: %s", argv[0]);
-        pr_debug("Group:%s Event:%s probe:%c\n", *group, *event, pr);
-
-        if (!pp)
-                goto end;
+        pr_debug("Group:%s Event:%s probe:%c\n", pp->group, pp->event, pr);
 
         pp->retprobe = (pr == 'r');
 
         /* Scan function name and offset */
-        ret = sscanf(argv[1], "%a[^+]+%d", (float *)(void *)&pp->function, &pp->offset);
+        ret = sscanf(argv[1], "%a[^+]+%d", (float *)(void *)&pp->function,
+                     &pp->offset);
         if (ret == 1)
                 pp->offset = 0;
 
@@ -235,7 +246,6 @@ void parse_trace_kprobe_event(const char *str, char **group, char **event,
                         die("Failed to copy argument.");
         }
 
-end:
         argv_free(argv);
 }
 
@@ -368,6 +378,10 @@ static void clear_probe_point(struct probe_point *pp)
 {
         int i;
 
+        if (pp->event)
+                free(pp->event);
+        if (pp->group)
+                free(pp->group);
         if (pp->function)
                 free(pp->function);
         if (pp->file)
@@ -382,13 +396,13 @@ static void clear_probe_point(struct probe_point *pp)
 }
 
 /* Show an event */
-static void show_perf_probe_event(const char *group, const char *event,
-                                  const char *place, struct probe_point *pp)
+static void show_perf_probe_event(const char *event, const char *place,
+                                  struct probe_point *pp)
 {
         int i, ret;
         char buf[128];
 
-        ret = e_snprintf(buf, 128, "%s:%s", group, event);
+        ret = e_snprintf(buf, 128, "%s:%s", pp->group, event);
         if (ret < 0)
                 die("Failed to copy event: %s", strerror(-ret));
         printf("  %-40s (on %s", buf, place);
@@ -405,7 +419,6 @@ static void show_perf_probe_event(const char *group, const char *event,
 void show_perf_probe_events(void)
 {
         int fd, nr;
-        char *group, *event;
         struct probe_point pp;
         struct strlist *rawlist;
         struct str_node *ent;
@@ -415,16 +428,14 @@ void show_perf_probe_events(void)
         close(fd);
 
         strlist__for_each(ent, rawlist) {
-                parse_trace_kprobe_event(ent->s, &group, &event, &pp);
+                parse_trace_kprobe_event(ent->s, &pp);
                 /* Synthesize only event probe point */
                 nr = pp.nr_args;
                 pp.nr_args = 0;
                 synthesize_perf_probe_event(&pp);
                 pp.nr_args = nr;
                 /* Show an event */
-                show_perf_probe_event(group, event, pp.probes[0], &pp);
-                free(group);
-                free(event);
+                show_perf_probe_event(pp.event, pp.probes[0], &pp);
                 clear_probe_point(&pp);
         }
 
@@ -434,24 +445,25 @@ void show_perf_probe_events(void)
 /* Get current perf-probe event names */
 static struct strlist *get_perf_event_names(int fd, bool include_group)
 {
-        char *group, *event;
         char buf[128];
         struct strlist *sl, *rawlist;
         struct str_node *ent;
+        struct probe_point pp;
 
+        memset(&pp, 0, sizeof(pp));
         rawlist = get_trace_kprobe_event_rawlist(fd);
 
         sl = strlist__new(true, NULL);
         strlist__for_each(ent, rawlist) {
-                parse_trace_kprobe_event(ent->s, &group, &event, NULL);
+                parse_trace_kprobe_event(ent->s, &pp);
                 if (include_group) {
-                        if (e_snprintf(buf, 128, "%s:%s", group, event) < 0)
+                        if (e_snprintf(buf, 128, "%s:%s", pp.group,
+                                       pp.event) < 0)
                                 die("Failed to copy group:event name.");
                         strlist__add(sl, buf);
                 } else
-                        strlist__add(sl, event);
-                free(group);
-                free(event);
+                        strlist__add(sl, pp.event);
+                clear_probe_point(&pp);
         }
 
         strlist__delete(rawlist);
@@ -507,19 +519,23 @@ void add_trace_kprobe_events(struct probe_point *probes, int nr_probes)
 
         for (j = 0; j < nr_probes; j++) {
                 pp = probes + j;
+                if (!pp->event)
+                        pp->event = strdup(pp->function);
+                if (!pp->group)
+                        pp->group = strdup(PERFPROBE_GROUP);
+                DIE_IF(!pp->event || !pp->group);
                 for (i = 0; i < pp->found; i++) {
                         /* Get an unused new event name */
-                        get_new_event_name(event, 64, pp->function, namelist);
+                        get_new_event_name(event, 64, pp->event, namelist);
                         snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s\n",
                                  pp->retprobe ? 'r' : 'p',
-                                 PERFPROBE_GROUP, event,
+                                 pp->group, event,
                                  pp->probes[i]);
                         write_trace_kprobe_event(fd, buf);
                         printf("Added new event:\n");
                         /* Get the first parameter (probe-point) */
                         sscanf(pp->probes[i], "%s", buf);
-                        show_perf_probe_event(PERFPROBE_GROUP, event,
-                                              buf, pp);
+                        show_perf_probe_event(event, buf, pp);
                         /* Add added event name to namelist */
                         strlist__add(namelist, event);
                 }
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 028575b5fc3b..8bb22f5246cc 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -8,8 +8,7 @@
 extern void parse_perf_probe_event(const char *str, struct probe_point *pp,
                                    bool *need_dwarf);
 extern int synthesize_perf_probe_event(struct probe_point *pp);
-extern void parse_trace_kprobe_event(const char *str, char **group,
-                                     char **event, struct probe_point *pp);
+extern void parse_trace_kprobe_event(const char *str, struct probe_point *pp);
 extern int synthesize_trace_kprobe_event(struct probe_point *pp);
 extern void add_trace_kprobe_events(struct probe_point *probes, int nr_probes);
 extern void del_trace_kprobe_events(struct strlist *dellist);
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index bdebca6697d2..5e4050ce2963 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -12,6 +12,9 @@ static inline int is_c_varname(const char *name)
 }
 
 struct probe_point {
+        char    *event;         /* Event name */
+        char    *group;         /* Event group */
+
         /* Inputs */
         char    *file;          /* File name */
         int     line;           /* Line number */