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* [PATCH AUTOSEL 5.7 07/60] io_uring: fix req->work corruption
       [not found] <20200810191028.3793884-1-sashal@kernel.org>
@ 2020-08-10 19:09 ` Sasha Levin
  2020-08-10 19:10 ` [PATCH AUTOSEL 5.7 57/60] io_uring: fix racy overflow count reporting Sasha Levin
  2020-08-10 19:10 ` [PATCH AUTOSEL 5.7 58/60] io_uring: fix stalled deferred requests Sasha Levin
  2 siblings, 0 replies; 3+ messages in thread
From: Sasha Levin @ 2020-08-10 19:09 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Pavel Begunkov, Jens Axboe, Sasha Levin, io-uring, linux-fsdevel

From: Pavel Begunkov <asml.silence@gmail.com>

[ Upstream commit 8ef77766ba8694968ed4ba24311b4bacee14f235 ]

req->work and req->task_work are in a union, so io_req_task_queue() screws
everything that was in work. De-union them for now.

[  704.367253] BUG: unable to handle page fault for address:
	ffffffffaf7330d0
[  704.367256] #PF: supervisor write access in kernel mode
[  704.367256] #PF: error_code(0x0003) - permissions violation
[  704.367261] CPU: 6 PID: 1654 Comm: io_wqe_worker-0 Tainted: G
I       5.8.0-rc2-00038-ge28d0bdc4863-dirty #498
[  704.367265] RIP: 0010:_raw_spin_lock+0x1e/0x36
...
[  704.367276]  __alloc_fd+0x35/0x150
[  704.367279]  __get_unused_fd_flags+0x25/0x30
[  704.367280]  io_openat2+0xcb/0x1b0
[  704.367283]  io_issue_sqe+0x36a/0x1320
[  704.367294]  io_wq_submit_work+0x58/0x160
[  704.367295]  io_worker_handle_work+0x2a3/0x430
[  704.367296]  io_wqe_worker+0x2a0/0x350
[  704.367301]  kthread+0x136/0x180
[  704.367304]  ret_from_fork+0x22/0x30

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/io_uring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 4e09af1d5d223..80a612d1e12bb 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -645,12 +645,12 @@ struct io_kiocb {
 		 * restore the work, if needed.
 		 */
 		struct {
-			struct callback_head	task_work;
 			struct hlist_node	hash_node;
 			struct async_poll	*apoll;
 		};
 		struct io_wq_work	work;
 	};
+	struct callback_head	task_work;
 };
 
 #define IO_PLUG_THRESHOLD		2
-- 
2.25.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH AUTOSEL 5.7 57/60] io_uring: fix racy overflow count reporting
       [not found] <20200810191028.3793884-1-sashal@kernel.org>
  2020-08-10 19:09 ` [PATCH AUTOSEL 5.7 07/60] io_uring: fix req->work corruption Sasha Levin
@ 2020-08-10 19:10 ` Sasha Levin
  2020-08-10 19:10 ` [PATCH AUTOSEL 5.7 58/60] io_uring: fix stalled deferred requests Sasha Levin
  2 siblings, 0 replies; 3+ messages in thread
From: Sasha Levin @ 2020-08-10 19:10 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Pavel Begunkov, Jens Axboe, Sasha Levin, io-uring, linux-fsdevel

From: Pavel Begunkov <asml.silence@gmail.com>

[ Upstream commit b2bd1cf99f3e7c8fbf12ea07af2c6998e1209e25 ]

All ->cq_overflow modifications should be under completion_lock,
otherwise it can report a wrong number to the userspace. Fix it in
io_uring_cancel_files().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/io_uring.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 80a612d1e12bb..d04fede20acb8 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7573,10 +7573,9 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
 				clear_bit(0, &ctx->sq_check_overflow);
 				clear_bit(0, &ctx->cq_check_overflow);
 			}
-			spin_unlock_irq(&ctx->completion_lock);
-
 			WRITE_ONCE(ctx->rings->cq_overflow,
 				atomic_inc_return(&ctx->cached_cq_overflow));
+			spin_unlock_irq(&ctx->completion_lock);
 
 			/*
 			 * Put inflight ref and overflow ref. If that's
-- 
2.25.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH AUTOSEL 5.7 58/60] io_uring: fix stalled deferred requests
       [not found] <20200810191028.3793884-1-sashal@kernel.org>
  2020-08-10 19:09 ` [PATCH AUTOSEL 5.7 07/60] io_uring: fix req->work corruption Sasha Levin
  2020-08-10 19:10 ` [PATCH AUTOSEL 5.7 57/60] io_uring: fix racy overflow count reporting Sasha Levin
@ 2020-08-10 19:10 ` Sasha Levin
  2 siblings, 0 replies; 3+ messages in thread
From: Sasha Levin @ 2020-08-10 19:10 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Pavel Begunkov, Jens Axboe, Sasha Levin, io-uring, linux-fsdevel

From: Pavel Begunkov <asml.silence@gmail.com>

[ Upstream commit dd9dfcdf5a603680458f5e7b0d2273c66e5417db ]

Always do io_commit_cqring() after completing a request, even if it was
accounted as overflowed on the CQ side. Failing to do that may lead to
not to pushing deferred requests when needed, and so stalling the whole
ring.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/io_uring.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index d04fede20acb8..5d33c05de02e5 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7575,6 +7575,7 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
 			}
 			WRITE_ONCE(ctx->rings->cq_overflow,
 				atomic_inc_return(&ctx->cached_cq_overflow));
+			io_commit_cqring(ctx);
 			spin_unlock_irq(&ctx->completion_lock);
 
 			/*
-- 
2.25.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2020-08-10 19:29 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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     [not found] <20200810191028.3793884-1-sashal@kernel.org>
2020-08-10 19:09 ` [PATCH AUTOSEL 5.7 07/60] io_uring: fix req->work corruption Sasha Levin
2020-08-10 19:10 ` [PATCH AUTOSEL 5.7 57/60] io_uring: fix racy overflow count reporting Sasha Levin
2020-08-10 19:10 ` [PATCH AUTOSEL 5.7 58/60] io_uring: fix stalled deferred requests Sasha Levin

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