block: use for_each_thread() in sys_ioprio_set()/sys_ioprio_get()
IOPRIO_WHO_USER case in sys_ioprio_set()/sys_ioprio_get() are using
while_each_thread(), which is unsafe under RCU lock according to commit
0c740d0afc3bff0a ("introduce for_each_thread() to replace the buggy
while_each_thread()"). Use for_each_thread() (via
for_each_process_thread()) which is safe under RCU lock.
Link: http://lkml.kernel.org/r/201702011947.DBD56740.OMVHOLOtSJFFFQ@I-love.SAKURA.ne.jp
Link: http://lkml.kernel.org/r/1486041779-4401-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/block/ioprio.c b/block/ioprio.c
index 01b8116..3790669 100644
--- a/block/ioprio.c
+++ b/block/ioprio.c
@@ -122,14 +122,14 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
if (!user)
break;
- do_each_thread(g, p) {
+ for_each_process_thread(g, p) {
if (!uid_eq(task_uid(p), uid) ||
!task_pid_vnr(p))
continue;
ret = set_task_ioprio(p, ioprio);
if (ret)
goto free_uid;
- } while_each_thread(g, p);
+ }
free_uid:
if (who)
free_uid(user);
@@ -222,7 +222,7 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
if (!user)
break;
- do_each_thread(g, p) {
+ for_each_process_thread(g, p) {
if (!uid_eq(task_uid(p), user->uid) ||
!task_pid_vnr(p))
continue;
@@ -233,7 +233,7 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
ret = tmpio;
else
ret = ioprio_best(ret, tmpio);
- } while_each_thread(g, p);
+ }
if (who)
free_uid(user);
