From 612dafabb6a0fa62e9b86f11da5d37ee11dea28f Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Wed, 22 Feb 2017 15:40:50 -0800 Subject: [PATCH] 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 --- block/ioprio.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) 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); -- 2.20.1