From: Pavel Begunkov <[email protected]>
To: [email protected]
Cc: Jens Axboe <[email protected]>, [email protected]
Subject: [PATCH 2/2] io_uring: fix unprotected iopoll overflow
Date: Thu, 7 Sep 2023 13:50:08 +0100 [thread overview]
Message-ID: <ae1902f240b9f73c10136354bafe6cd562bb76d8.1694054436.git.asml.silence@gmail.com> (raw)
In-Reply-To: <[email protected]>
[ 71.490669] WARNING: CPU: 3 PID: 17070 at io_uring/io_uring.c:769
io_cqring_event_overflow+0x47b/0x6b0
[ 71.498381] Call Trace:
[ 71.498590] <TASK>
[ 71.501858] io_req_cqe_overflow+0x105/0x1e0
[ 71.502194] __io_submit_flush_completions+0x9f9/0x1090
[ 71.503537] io_submit_sqes+0xebd/0x1f00
[ 71.503879] __do_sys_io_uring_enter+0x8c5/0x2380
[ 71.507360] do_syscall_64+0x39/0x80
We decoupled CQ locking from ->task_complete but haven't fixed up places
forcing locking for CQ overflows.
Fixes: ec26c225f06f5 ("io_uring: merge iopoll and normal completion paths")
Signed-off-by: Pavel Begunkov <[email protected]>
---
io_uring/io_uring.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 4674203c1cac..6cce8948bddf 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -883,7 +883,7 @@ static void __io_flush_post_cqes(struct io_ring_ctx *ctx)
struct io_uring_cqe *cqe = &ctx->completion_cqes[i];
if (!io_fill_cqe_aux(ctx, cqe->user_data, cqe->res, cqe->flags)) {
- if (ctx->task_complete) {
+ if (ctx->lockless_cq) {
spin_lock(&ctx->completion_lock);
io_cqring_event_overflow(ctx, cqe->user_data,
cqe->res, cqe->flags, 0, 0);
@@ -1541,7 +1541,7 @@ void __io_submit_flush_completions(struct io_ring_ctx *ctx)
if (!(req->flags & REQ_F_CQE_SKIP) &&
unlikely(!io_fill_cqe_req(ctx, req))) {
- if (ctx->task_complete) {
+ if (ctx->lockless_cq) {
spin_lock(&ctx->completion_lock);
io_req_cqe_overflow(req);
spin_unlock(&ctx->completion_lock);
--
2.41.0
next prev parent reply other threads:[~2023-09-07 16:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-07 12:50 [PATCH 0/2] for-next fixes Pavel Begunkov
2023-09-07 12:50 ` [PATCH 1/2] io_uring: break out of iowq iopoll on teardown Pavel Begunkov
2023-09-07 12:50 ` Pavel Begunkov [this message]
2023-09-07 15:02 ` [PATCH 0/2] for-next fixes Jens Axboe
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