Commit 93e197e5 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
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io_uring: use WRITE_ONCE for user shared memory 



IORING_SETUP_NO_MMAP rings remain user accessible even before the ctx
setup is finalised, so use WRITE_ONCE consistently when initialising
rings.

Fixes: 03d89a2d ("io_uring: support for user allocated memory for rings/sqes")
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 75c299a9

io_uring/io_uring.c

+6 −4
Original line number Diff line number Diff line
@@ -3381,10 +3381,6 @@ static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx, 


	if (!(ctx->flags & IORING_SETUP_NO_SQARRAY))

		ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);

	rings->sq_ring_mask = p->sq_entries - 1;

	rings->cq_ring_mask = p->cq_entries - 1;

	rings->sq_ring_entries = p->sq_entries;

	rings->cq_ring_entries = p->cq_entries;



	memset(&rd, 0, sizeof(rd));

	rd.size = PAGE_ALIGN(sq_size);
@@ -3398,6 +3394,12 @@ static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx, 
		return ret;

	}

	ctx->sq_sqes = io_region_get_ptr(&ctx->sq_region);



	memset(rings, 0, sizeof(*rings));

	WRITE_ONCE(rings->sq_ring_mask, ctx->sq_entries - 1);

	WRITE_ONCE(rings->cq_ring_mask, ctx->cq_entries - 1);

	WRITE_ONCE(rings->sq_ring_entries, ctx->sq_entries);

	WRITE_ONCE(rings->cq_ring_entries, ctx->cq_entries);

	return 0;

}