| From: Arnaldo Carvalho de Melo <acme@redhat.com> |
| Date: Fri, 8 Apr 2016 11:32:15 -0300 |
| Subject: perf tools: Use readdir() instead of deprecated readdir_r() |
| |
| commit 7093b4c963cc4e344e490c774924a180602a7092 upstream. |
| |
| The readdir() function is thread safe as long as just one thread uses a |
| DIR, which is the case when synthesizing events for pre-existing threads |
| by traversing /proc, 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 /tmp/build/perf/util/event.o |
| util/event.c: In function '__event__synthesize_thread': |
| util/event.c:466:2: error: 'readdir_r' is deprecated [-Werror=deprecated-declarations] |
| while (!readdir_r(tasks, &dirent, &next) && next) { |
| ^~~~~ |
| In file included from /usr/include/features.h:368:0, |
| from /usr/include/stdint.h:25, |
| from /usr/lib/gcc/x86_64-redhat-linux/6.0.0/include/stdint.h:9, |
| from /git/linux/tools/include/linux/types.h:6, |
| from util/event.c:1: |
| /usr/include/dirent.h:189:12: note: declared here |
| |
| Cc: Adrian Hunter <adrian.hunter@intel.com> |
| Cc: David Ahern <dsahern@gmail.com> |
| Cc: Jiri Olsa <jolsa@kernel.org> |
| Cc: Namhyung Kim <namhyung@kernel.org> |
| Cc: Wang Nan <wangnan0@huawei.com> |
| Link: http://lkml.kernel.org/n/tip-i1vj7nyjp2p750rirxgrfd3c@git.kernel.org |
| Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
| [bwh: Backported to 3.16: adjust context] |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| tools/perf/util/event.c | 12 ++++++------ |
| 1 file changed, 6 insertions(+), 6 deletions(-) |
| |
| --- a/tools/perf/util/event.c |
| +++ b/tools/perf/util/event.c |
| @@ -331,7 +331,7 @@ static int __event__synthesize_thread(un |
| { |
| char filename[PATH_MAX]; |
| DIR *tasks; |
| - struct dirent dirent, *next; |
| + struct dirent *dirent; |
| pid_t tgid; |
| |
| /* special case: only send one comm event using passed in pid */ |
| @@ -358,12 +358,12 @@ static int __event__synthesize_thread(un |
| return 0; |
| } |
| |
| - while (!readdir_r(tasks, &dirent, &next) && next) { |
| + while ((dirent = readdir(tasks)) != NULL) { |
| char *end; |
| int rc = 0; |
| pid_t _pid; |
| |
| - _pid = strtol(dirent.d_name, &end, 10); |
| + _pid = strtol(dirent->d_name, &end, 10); |
| if (*end) |
| continue; |
| |
| @@ -464,7 +464,7 @@ int perf_event__synthesize_threads(struc |
| { |
| DIR *proc; |
| char proc_path[PATH_MAX]; |
| - struct dirent dirent, *next; |
| + struct dirent *dirent; |
| union perf_event *comm_event, *mmap_event, *fork_event; |
| int err = -1; |
| |
| @@ -489,9 +489,9 @@ int perf_event__synthesize_threads(struc |
| if (proc == NULL) |
| goto out_free_fork; |
| |
| - while (!readdir_r(proc, &dirent, &next) && next) { |
| + while ((dirent = readdir(proc)) != NULL) { |
| char *end; |
| - 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; |