perf probe: Search SDT/cached event from all probe caches

Search SDT/cached event from all probe caches if user doesn't pass any
binary. With this, we don't have to specify target binary for SDT and
named cached events (which start with %).

E.g. without this, a target binary must be passed with -x.

  # perf probe -x /usr/lib64/libc-2.20.so -a %sdt_libc:\*

With this change, we don't need it anymore.

  # perf probe -a %sdt_libc:\*

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
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/146831792812.17065.2353705982669445313.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 86 insertions, 19 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 7b96e687568e..c63e3b8704fe 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2557,41 +2557,60 @@ static int probe_trace_event__set_name(struct probe_trace_event *tev,
         return 0;
 }
 
-static int __add_probe_trace_events(struct perf_probe_event *pev,
-                                     struct probe_trace_event *tevs,
-                                     int ntevs, bool allow_suffix)
+static int __open_probe_file_and_namelist(bool uprobe,
+                                          struct strlist **namelist)
 {
-        int i, fd, ret;
-        struct probe_trace_event *tev = NULL;
-        struct probe_cache *cache = NULL;
-        struct strlist *namelist;
+        int fd;
 
-        fd = probe_file__open(PF_FL_RW | (pev->uprobes ? PF_FL_UPROBE : 0));
+        fd = probe_file__open(PF_FL_RW | (uprobe ? PF_FL_UPROBE : 0));
         if (fd < 0)
                 return fd;
 
         /* Get current event names */
-        namelist = probe_file__get_namelist(fd);
-        if (!namelist) {
+        *namelist = probe_file__get_namelist(fd);
+        if (!(*namelist)) {
                 pr_debug("Failed to get current event list.\n");
-                ret = -ENOMEM;
-                goto close_out;
+                close(fd);
+                return -ENOMEM;
         }
+        return fd;
+}
+
+static int __add_probe_trace_events(struct perf_probe_event *pev,
+                                     struct probe_trace_event *tevs,
+                                     int ntevs, bool allow_suffix)
+{
+        int i, fd[2] = {-1, -1}, up, ret;
+        struct probe_trace_event *tev = NULL;
+        struct probe_cache *cache = NULL;
+        struct strlist *namelist[2] = {NULL, NULL};
+
+        up = pev->uprobes ? 1 : 0;
+        fd[up] = __open_probe_file_and_namelist(up, &namelist[up]);
+        if (fd[up] < 0)
+                return fd[up];
 
         ret = 0;
         for (i = 0; i < ntevs; i++) {
                 tev = &tevs[i];
+                up = tev->uprobes ? 1 : 0;
+                if (fd[up] == -1) {     /* Open the kprobe/uprobe_events */
+                        fd[up] = __open_probe_file_and_namelist(up,
+                                                                &namelist[up]);
+                        if (fd[up] < 0)
+                                goto close_out;
+                }
                 /* Skip if the symbol is out of .text or blacklisted */
                 if (!tev->point.symbol && !pev->uprobes)
                         continue;
 
                 /* Set new name for tev (and update namelist) */
-                ret = probe_trace_event__set_name(tev, pev, namelist,
+                ret = probe_trace_event__set_name(tev, pev, namelist[up],
                                                   allow_suffix);
                 if (ret < 0)
                         break;
 
-                ret = probe_file__add_event(fd, tev);
+                ret = probe_file__add_event(fd[up], tev);
                 if (ret < 0)
                         break;
 
@@ -2614,9 +2633,12 @@ static int __add_probe_trace_events(struct perf_probe_event *pev,
                 probe_cache__delete(cache);
         }
 
-        strlist__delete(namelist);
 close_out:
-        close(fd);
+        for (up = 0; up < 2; up++) {
+                strlist__delete(namelist[up]);
+                if (fd[up] >= 0)
+                        close(fd[up]);
+        }
         return ret;
 }
 
@@ -2989,6 +3011,48 @@ static int find_cached_events(struct perf_probe_event *pev,
         return ret;
 }
 
+/* Try to find probe_trace_event from all probe caches */
+static int find_cached_events_all(struct perf_probe_event *pev,
+                                   struct probe_trace_event **tevs)
+{
+        struct probe_trace_event *tmp_tevs = NULL;
+        struct strlist *bidlist;
+        struct str_node *nd;
+        char *pathname;
+        int ntevs = 0;
+        int ret;
+
+        /* Get the buildid list of all valid caches */
+        bidlist = build_id_cache__list_all(true);
+        if (!bidlist) {
+                ret = -errno;
+                pr_debug("Failed to get buildids: %d\n", ret);
+                return ret;
+        }
+
+        ret = 0;
+        strlist__for_each_entry(nd, bidlist) {
+                pathname = build_id_cache__origname(nd->s);
+                ret = find_cached_events(pev, &tmp_tevs, pathname);
+                /* In the case of cnt == 0, we just skip it */
+                if (ret > 0)
+                        ret = concat_probe_trace_events(tevs, &ntevs,
+                                                        &tmp_tevs, ret);
+                free(pathname);
+                if (ret < 0)
+                        break;
+        }
+        strlist__delete(bidlist);
+
+        if (ret < 0) {
+                clear_probe_trace_events(*tevs, ntevs);
+                zfree(tevs);
+        } else
+                ret = ntevs;
+
+        return ret;
+}
+
 static int find_probe_trace_events_from_cache(struct perf_probe_event *pev,
                                               struct probe_trace_event **tevs)
 {
@@ -2998,10 +3062,13 @@ static int find_probe_trace_events_from_cache(struct perf_probe_event *pev,
         struct str_node *node;
         int ret, i;
 
-        if (pev->sdt)
+        if (pev->sdt) {
                 /* For SDT/cached events, we use special search functions */
-                return find_cached_events(pev, tevs, pev->target);
-
+                if (!pev->target)
+                        return find_cached_events_all(pev, tevs);
+                else
+                        return find_cached_events(pev, tevs, pev->target);
+        }
         cache = probe_cache__new(pev->target);
         if (!cache)
                 return 0;