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 <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f7bffddd71b08f28a877d44d37ac953ddb01590d.1672915663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Bug: 268174392
(cherry picked from commit e0140e9da3)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Pavel Begunkov
2023-01-05 10:49:15 +00:00
committed by Treehugger Robot
parent a4d056e350
commit fee5372abf

View File

@@ -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);