[PATCH] io_uring/rsrc: take unsigned index in io_rsrc_node_lookup()

[PATCH] io_uring/rsrc: take unsigned index in io_rsrc_node_lookup()

[Caleb Sander Mateos]

io_rsrc_node_lookup() takes a signed int index as input and compares it
to an unsigned length. Since the signed int is implicitly cast to an
unsigned int for the comparison and the length is bounded by
IORING_MAX_FIXED_FILES/IORING_MAX_REG_BUFFERS, negative indices are
already rejected on architectures where int is at least 32 bits. Make
this a bit clearer and avoid compiler warnings for comparisons of
signed and unsigned values by taking an unsigned int index instead.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 io_uring/rsrc.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index d603f6a47f5e..4a5db2ad1af2 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -88,11 +88,11 @@ int io_validate_user_buf_range(u64 uaddr, u64 ulen);
 
 bool io_check_coalesce_buffer(struct page **page_array, int nr_pages,
 			      struct io_imu_folio_data *data);
 
 static inline struct io_rsrc_node *io_rsrc_node_lookup(struct io_rsrc_data *data,
-						       int index)
+						       unsigned int index)
 {
 	if (index < data->nr)
 		return data->nodes[array_index_nospec(index, data->nr)];
 	return NULL;
 }
-- 
2.45.2

Re: [PATCH] io_uring/rsrc: take unsigned index in io_rsrc_node_lookup()

[Jens Axboe]

On Thu, 22 Jan 2026 14:45:04 -0700, Caleb Sander Mateos wrote:
> io_rsrc_node_lookup() takes a signed int index as input and compares it
> to an unsigned length. Since the signed int is implicitly cast to an
> unsigned int for the comparison and the length is bounded by
> IORING_MAX_FIXED_FILES/IORING_MAX_REG_BUFFERS, negative indices are
> already rejected on architectures where int is at least 32 bits. Make
> this a bit clearer and avoid compiler warnings for comparisons of
> signed and unsigned values by taking an unsigned int index instead.
> 
> [...]

Applied, thanks!

[1/1] io_uring/rsrc: take unsigned index in io_rsrc_node_lookup()
      commit: 82dadc8a494758093e775336390cb31033c6f9a3

Best regards,
-- 
Jens Axboe