From: Tetsuo Handa Date: Wed, 22 Feb 2017 23:40:50 +0000 (-0800) Subject: block: use for_each_thread() in sys_ioprio_set()/sys_ioprio_get() X-Git-Tag: v4.11-rc1~106^2~120 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=612dafabb6a0fa62e9b86f11da5d37ee11dea28f;p=linux.git 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 Cc: Oleg Nesterov Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/block/ioprio.c b/block/ioprio.c index 01b8116298a1..3790669232ff 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);