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>

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 13ab4b842d49ba30f4e74a0854e9cf30fc21c2a6..87c424de79ee39653d3ef7041b878cda97ea459c 100644 (file)
--- 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);
 }