From fee5372abf8ae42131af91cd88cf3790892a7599 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 5 Jan 2023 10:49:15 +0000 Subject: [PATCH] UPSTREAM: io_uring: fix CQ waiting timeout handling commit 12521a5d5cb7ff0ad43eadfc9c135d86e1131fa8 upstream. Jiffy to ktime CQ waiting conversion broke how we treat timeouts, in particular we rearm it anew every time we get into io_cqring_wait_schedule() without adjusting the timeout. Waiting for 2 CQEs and getting a task_work in the middle may double the timeout value, or even worse in some cases task may wait indefinitely. Cc: stable@vger.kernel.org Fixes: 228339662b398 ("io_uring: don't convert to jiffies for waiting on timeouts") Change-Id: If8605a13266ae2b49b1f7d7cd5ee092f9ffd2805 Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/f7bffddd71b08f28a877d44d37ac953ddb01590d.1672915663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Bug: 268174392 (cherry picked from commit e0140e9da31e1f89baca5f175e073e8aed92688f) Signed-off-by: Greg Kroah-Hartman --- io_uring/io_uring.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 35b877bd636f..07ad8347f980 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -7528,7 +7528,7 @@ static int io_run_task_work_sig(void) /* when returns >0, the caller should retry */ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, struct io_wait_queue *iowq, - ktime_t timeout) + ktime_t *timeout) { int ret; @@ -7540,7 +7540,7 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, if (test_bit(0, &ctx->check_cq_overflow)) return 1; - if (!schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS)) + if (!schedule_hrtimeout(timeout, HRTIMER_MODE_ABS)) return -ETIME; return 1; } @@ -7603,7 +7603,7 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, } prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq, TASK_INTERRUPTIBLE); - ret = io_cqring_wait_schedule(ctx, &iowq, timeout); + ret = io_cqring_wait_schedule(ctx, &iowq, &timeout); finish_wait(&ctx->cq_wait, &iowq.wq); cond_resched(); } while (ret > 0);