[PATCH v3 03/12] io_uring: change ring size calculation for CQE32

[Stefan Roesch]

This changes the function rings_size to take large CQE's into account.

Co-developed-by: Jens Axboe <axboe at kernel.dk>
Signed-off-by: Stefan Roesch <shr at fb.com>
Signed-off-by: Jens Axboe <axboe at kernel.dk>
---
 fs/io_uring.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index bf2b02518332..9712483d3a17 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -9693,8 +9693,8 @@ static void *io_mem_alloc(size_t size)
 	return (void *) __get_free_pages(gfp, get_order(size));
 }
 
-static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
-				size_t *sq_offset)
+static unsigned long rings_size(struct io_ring_ctx *ctx, unsigned int sq_entries,
+				unsigned int cq_entries, size_t *sq_offset)
 {
 	struct io_rings *rings;
 	size_t off, sq_array_size;
@@ -9702,6 +9702,10 @@ static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
 	off = struct_size(rings, cqes, cq_entries);
 	if (off == SIZE_MAX)
 		return SIZE_MAX;
+	if (ctx->flags & IORING_SETUP_CQE32) {
+		if (check_shl_overflow(off, 1, &off))
+			return SIZE_MAX;
+	}
 
 #ifdef CONFIG_SMP
 	off = ALIGN(off, SMP_CACHE_BYTES);
@@ -11365,7 +11369,7 @@ static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx,
 	ctx->sq_entries = p->sq_entries;
 	ctx->cq_entries = p->cq_entries;
 
-	size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
+	size = rings_size(ctx, p->sq_entries, p->cq_entries, &sq_array_offset);
 	if (size == SIZE_MAX)
 		return -EOVERFLOW;
 
-- 
2.30.2