[PATCH 1/3] io_uring: simplify io_mem_alloc return values

[Pavel Begunkov <asml.silence@gmail.com>]

io_mem_alloc() returns a pointer on success and a pointer-encoded error
otherwise. However, it can only fail with -ENOMEM, just return NULL on
failure. PTR_ERR is usually pretty error prone.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/io_uring.c | 14 +++++---------
 io_uring/kbuf.c     |  4 ++--
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index e7d7a456b489..1d0eac0cc8aa 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2802,12 +2802,8 @@ static void io_rings_free(struct io_ring_ctx *ctx)
 void *io_mem_alloc(size_t size)
 {
 	gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP;
-	void *ret;
 
-	ret = (void *) __get_free_pages(gfp, get_order(size));
-	if (ret)
-		return ret;
-	return ERR_PTR(-ENOMEM);
+	return (void *) __get_free_pages(gfp, get_order(size));
 }
 
 static unsigned long rings_size(struct io_ring_ctx *ctx, unsigned int sq_entries,
@@ -3762,8 +3758,8 @@ static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx,
 	else
 		rings = io_rings_map(ctx, p->cq_off.user_addr, size);
 
-	if (IS_ERR(rings))
-		return PTR_ERR(rings);
+	if (!rings)
+		return -ENOMEM;
 
 	ctx->rings = rings;
 	if (!(ctx->flags & IORING_SETUP_NO_SQARRAY))
@@ -3787,9 +3783,9 @@ static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx,
 	else
 		ptr = io_sqes_map(ctx, p->sq_off.user_addr, size);
 
-	if (IS_ERR(ptr)) {
+	if (!ptr) {
 		io_rings_free(ctx);
-		return PTR_ERR(ptr);
+		return -ENOMEM;
 	}
 
 	ctx->sq_sqes = ptr;
diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
index 9be42bff936b..0677eae92e79 100644
--- a/io_uring/kbuf.c
+++ b/io_uring/kbuf.c
@@ -627,8 +627,8 @@ static int io_alloc_pbuf_ring(struct io_ring_ctx *ctx,
 	ibf = io_lookup_buf_free_entry(ctx, ring_size);
 	if (!ibf) {
 		ptr = io_mem_alloc(ring_size);
-		if (IS_ERR(ptr))
-			return PTR_ERR(ptr);
+		if (!ptr)
+			return -ENOMEM;
 
 		/* Allocate and store deferred free entry */
 		ibf = kmalloc(sizeof(*ibf), GFP_KERNEL_ACCOUNT);
-- 
2.43.0