perf tools: Dont stop PMU parsing on alias parse error

When an error happens during alias parsing currently the complete
parsing of all attributes of the PMU is stopped. This is breaks old perf
on a newer kernel that may have not-yet-know alias attributes (such as
.scale or .per-pkg).

Continue when some attribute is unparseable.

This is IMHO a stable candidate and should be backported to older
versions to avoid problems with newer kernels.

v2: Print warnings when something goes wrong.
v3: Change warning to debug output

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org # v3.6+
Link: http://lkml.kernel.org/r/1455749095-18358-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index cf59fbaee491c3495d98d606b13fa41b3ab5a7a3..ce61f79dbaae81344e2b41734edea211fcb33e29 100644 (file)
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -284,13 +284,12 @@ static int pmu_aliases_parse(char *dir, struct list_head *head)
 {
        struct dirent *evt_ent;
        DIR *event_dir;
-       int ret = 0;
 
        event_dir = opendir(dir);
        if (!event_dir)
                return -EINVAL;
 
-       while (!ret && (evt_ent = readdir(event_dir))) {
+       while ((evt_ent = readdir(event_dir))) {
                char path[PATH_MAX];
                char *name = evt_ent->d_name;
                FILE *file;
@@ -306,17 +305,19 @@ static int pmu_aliases_parse(char *dir, struct list_head *head)
 
                snprintf(path, PATH_MAX, "%s/%s", dir, name);
 
-               ret = -EINVAL;
                file = fopen(path, "r");
-               if (!file)
-                       break;
+               if (!file) {
+                       pr_debug("Cannot open %s\n", path);
+                       continue;
+               }
 
-               ret = perf_pmu__new_alias(head, dir, name, file);
+               if (perf_pmu__new_alias(head, dir, name, file) < 0)
+                       pr_debug("Cannot set up %s\n", name);
                fclose(file);
        }
 
        closedir(event_dir);
-       return ret;
+       return 0;
 }
 
 /*