On 2019-12-18 5:52 p.m., Michel Dänzer <[email protected]> wrote: >> this set adds support for removal of gpu drm dead code. >> >> patch2: >> `num_entries` is a data of unsigned type(compilers always treat as >> unsigned int) and SIZE_MAX == ~0, >> >> so there is a impossible condition: >> '(num_entries > ((~0) - 56) / 72) => (max(0-u32) > 256204778801521549)'.
>While this looks correct for 64-bit, where size_t is unsigned long, on 32-bit >it's unsigned int, in which case this isn't dead code. and On 2019-12-18 5:52 p.m., Christian König <christian.koenig@xxxxxxx> wrote: >NAK, that calculation is not correct on 32-bit systems. >Christian. Yes, you are right. I just figured this out (because our Server usually uses 64 bits). thanks. >>Signed-off-by: Pan Zhang <zhangpan26@xxxxxxxxxx> >>--- >> drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c | 4 ---- >> 1 file changed, 4 deletions(-) >>diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c >>b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c >>index 85b0515..10a7f30 100644 >>--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c >>+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c >>@@ -71,10 +71,6 @@ int amdgpu_bo_list_create(struct amdgpu_device *adev, >>struct drm_file *filp, >> unsigned i; >> int r; >> >>- if (num_entries > (SIZE_MAX - sizeof(struct amdgpu_bo_list)) >>- / sizeof(struct amdgpu_bo_list_entry)) >>- return -EINVAL; >>- >> size = sizeof(struct amdgpu_bo_list); >> size += num_entries * sizeof(struct amdgpu_bo_list_entry); >> list = kvmalloc(size, GFP_KERNEL); >> _______________________________________________ dri-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/dri-devel
