perf tools: Dont use openat()

openat() is still a young glibc facility, better to not use it in a
non performance critical program (perf list)

Many machines have older glibc (RHEL 4 Update 5 -> glibc-2.3.4-2.36
on my dev machine for example).

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ulrich Drepper <drepper@redhat.com>
LKML-Reference: <4ABB767D.6080004@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 20 insertions, 29 deletions

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 13ab4b842d49..87c424de79ee 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -165,33 +165,31 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
         DIR *sys_dir, *evt_dir;
         struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
         char id_buf[4];
-        int sys_dir_fd, fd;
+        int fd;
         u64 id;
         char evt_path[MAXPATHLEN];
+        char dir_path[MAXPATHLEN];
 
         if (valid_debugfs_mount(debugfs_path))
                 return NULL;
 
         sys_dir = opendir(debugfs_path);
         if (!sys_dir)
-                goto cleanup;
-        sys_dir_fd = dirfd(sys_dir);
+                return NULL;
 
         for_each_subsystem(sys_dir, sys_dirent, sys_next) {
-                int dfd = openat(sys_dir_fd, sys_dirent.d_name,
-                                 O_RDONLY|O_DIRECTORY), evt_dir_fd;
-                if (dfd == -1)
-                        continue;
-                evt_dir = fdopendir(dfd);
-                if (!evt_dir) {
-                        close(dfd);
+
+                snprintf(dir_path, MAXPATHLEN, "%s/%s", debugfs_path,
+                         sys_dirent.d_name);
+                evt_dir = opendir(dir_path);
+                if (!evt_dir)
                         continue;
-                }
-                evt_dir_fd = dirfd(evt_dir);
+
                 for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
-                        snprintf(evt_path, MAXPATHLEN, "%s/id",
+
+                        snprintf(evt_path, MAXPATHLEN, "%s/%s/id", dir_path,
                                  evt_dirent.d_name);
-                        fd = openat(evt_dir_fd, evt_path, O_RDONLY);
+                        fd = open(evt_path, O_RDONLY);
                         if (fd < 0)
                                 continue;
                         if (read(fd, id_buf, sizeof(id_buf)) < 0) {
@@ -225,7 +223,6 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
                 closedir(evt_dir);
         }
 
-cleanup:
         closedir(sys_dir);
         return NULL;
 }
@@ -761,28 +758,24 @@ static void print_tracepoint_events(void)
 {
         DIR *sys_dir, *evt_dir;
         struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
-        int sys_dir_fd;
         char evt_path[MAXPATHLEN];
+        char dir_path[MAXPATHLEN];
 
         if (valid_debugfs_mount(debugfs_path))
                 return;
 
         sys_dir = opendir(debugfs_path);
         if (!sys_dir)
-                goto cleanup;
-        sys_dir_fd = dirfd(sys_dir);
+                return;
 
         for_each_subsystem(sys_dir, sys_dirent, sys_next) {
-                int dfd = openat(sys_dir_fd, sys_dirent.d_name,
-                                 O_RDONLY|O_DIRECTORY), evt_dir_fd;
-                if (dfd == -1)
-                        continue;
-                evt_dir = fdopendir(dfd);
-                if (!evt_dir) {
-                        close(dfd);
+
+                snprintf(dir_path, MAXPATHLEN, "%s/%s", debugfs_path,
+                         sys_dirent.d_name);
+                evt_dir = opendir(dir_path);
+                if (!evt_dir)
                         continue;
-                }
-                evt_dir_fd = dirfd(evt_dir);
+
                 for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
                         snprintf(evt_path, MAXPATHLEN, "%s:%s",
                                  sys_dirent.d_name, evt_dirent.d_name);
@@ -791,8 +784,6 @@ static void print_tracepoint_events(void)
                 }
                 closedir(evt_dir);
         }
-
-cleanup:
         closedir(sys_dir);
 }