On 2023/5/31 16:31, Dan Carpenter wrote:
On Wed, May 31, 2023 at 12:38:26PM +0800, Su Hui wrote:
Use struct_size() instead of hand writing it.
This is less verbose and more informative.

Signed-off-by: Su Hui <su...@nfschina.com>
---
  drivers/gpu/drm/nouveau/nvif/object.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nvif/object.c 
b/drivers/gpu/drm/nouveau/nvif/object.c
index 4d1aaee8fe15..4bd693aa4ee0 100644
--- a/drivers/gpu/drm/nouveau/nvif/object.c
+++ b/drivers/gpu/drm/nouveau/nvif/object.c
@@ -65,7 +65,7 @@ nvif_object_sclass_get(struct nvif_object *object, struct 
nvif_sclass **psclass)
        u32 size;
while (1) {
-               size = sizeof(*args) + cnt * sizeof(args->sclass.oclass[0]);
+               size = struct_size(args, sclass.oclass, cnt);
This is from the original code, but now that you are using the
struct_size() macro static checkers will complain about it.  (Maybe they
don't yet?).  size is a u32.  Never save struct_size() returns to
anything except unsigned long or size_t.  (ssize_t is also fine, I
suppose).  Otherwise, you do not benefit from the integer overflow
checking.
Sorry, I don't notice the issue caused by type size.
You are right, this patch is wrong because of the type mismatch.
Thanks for your reply!

Su Hui

                if (!(args = kmalloc(size, GFP_KERNEL)))
                        return -ENOMEM;
                args->ioctl.version = 0;
regards,
dan carpenter

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