tjh.dev / kernel
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
1
fork

Configure Feed

Select the types of activity you want to include in your feed.

io_uring: fix mixed cqe overflow handling

I started to see zcrx data corruptions. That turned out to be due
to CQ tail pointing to a stale entry which happened to be from
a zcrx request. I.e. the tail is incremented without the CQE
memory being changed.

The culprit is __io_cqring_overflow_flush() passing "cqe32=true"
to io_get_cqe_overflow() for non-mixed CQE32 setups, which only
expects it to be set for mixed 32B CQEs and not for SETUP_CQE32.

The fix is slightly hacky, long term it's better to unify mixed and
CQE32 handling.

Fixes: e26dca67fde19 ("io_uring: add support for IORING_SETUP_CQE_MIXED")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

authored by

Pavel Begunkov and committed by
Jens Axboe f6dc5a36 f6041803

+2
+2
io_uring/io_uring.c
··· 634 634 is_cqe32 = true; 635 635 cqe_size <<= 1; 636 636 } 637 + if (ctx->flags & IORING_SETUP_CQE32) 638 + is_cqe32 = false; 637 639 638 640 if (!dying) { 639 641 if (!io_get_cqe_overflow(ctx, &cqe, true, is_cqe32))