On 3/28/24 22:53, Alex Elder wrote:
On 3/28/24 9:30 AM, Arnd Bergmann wrote:
From: Arnd Bergmann <arnd@xxxxxxxx>
clang-14 points out that the range check is always true on 64-bit
architectures since a u32 is not greater than the allowed size:
drivers/block/rbd.c:6079:17: error: result of comparison of constant
2305843009213693948 with expression of type 'u32' (aka 'unsigned
int') is always false
[-Werror,-Wtautological-constant-out-of-range-compare]
w
~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is harmless, so just change the type of the temporary to size_t
to shut up that warning.
This fixes the warning, but then the now size_t value is passed
to ceph_decode_32_safe(), which implies a different type conversion.
That too is not harmful, but...
Could we just cast the value in the comparison instead?
if ((size_t)snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
You could drop the space between sizeof and ( while
you're at it (I always used the space back then).
Agree.
- Xiubo
-Alex
Fixes: bb23e37acb2a ("rbd: refactor rbd_header_from_disk()")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/block/rbd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 26ff5cd2bf0a..cb25ee513ada 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -6062,7 +6062,7 @@ static int rbd_dev_v2_snap_context(struct
rbd_device *rbd_dev,
void *p;
void *end;
u64 seq;
- u32 snap_count;
+ size_t snap_count;
struct ceph_snap_context *snapc;
u32 i;
