4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Arnaldo Carvalho de Melo <a...@redhat.com> commit 3354cf71104de49326d19d2f9bdb1f66eea52ef4 upstream. The readdir() function is thread safe as long as just one thread uses a DIR, which is the case in thread_map, so, to avoid breaking the build with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r(). See: http://man7.org/linux/man-pages/man3/readdir.3.html "However, in modern implementations (including the glibc implementation), concurrent calls to readdir() that specify different directory streams are thread-safe. In cases where multiple threads must read from the same directory stream, using readdir() with external synchronization is still preferable to the use of the deprecated readdir_r(3) function." Noticed while building on a Fedora Rawhide docker container. Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: David Ahern <dsah...@gmail.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Wang Nan <wangn...@huawei.com> Link: http://lkml.kernel.org/n/tip-del8h2a0f40z75j4r42l9...@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- tools/perf/util/thread_map.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/tools/perf/util/thread_map.c +++ b/tools/perf/util/thread_map.c @@ -93,7 +93,7 @@ struct thread_map *thread_map__new_by_ui DIR *proc; int max_threads = 32, items, i; char path[NAME_MAX + 1 + 6]; - struct dirent dirent, *next, **namelist = NULL; + struct dirent *dirent, **namelist = NULL; struct thread_map *threads = thread_map__alloc(max_threads); if (threads == NULL) @@ -106,16 +106,16 @@ struct thread_map *thread_map__new_by_ui threads->nr = 0; atomic_set(&threads->refcnt, 1); - while (!readdir_r(proc, &dirent, &next) && next) { + while ((dirent = readdir(proc)) != NULL) { char *end; bool grow = false; struct stat st; - pid_t pid = strtol(dirent.d_name, &end, 10); + pid_t pid = strtol(dirent->d_name, &end, 10); if (*end) /* only interested in proper numerical dirents */ continue; - snprintf(path, sizeof(path), "/proc/%s", dirent.d_name); + snprintf(path, sizeof(path), "/proc/%s", dirent->d_name); if (stat(path, &st) != 0) continue;
