[PATCH] drm/amdgpu: potential shift wrapping bug

Dan Carpenter
2017-08-10T12:16:59Z

"frag_align" is a u64, so presumably we want to use the high bits as
well instead of shift wrapping.

Fixes: 6be7adb37d9b ("drm/amdgpu: increase fragmentation size for Vega10 v2")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index ba0407d12525..d9a8e942ac3b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1459,7 +1459,7 @@ static int amdgpu_vm_frag_ptes(struct amdgpu_pte_update_params *params,
/* SI and newer are optimized for 64KB */
unsigned pages_per_frag = AMDGPU_LOG2_PAGES_PER_FRAG(params->adev);
uint64_t frag_flags = AMDGPU_PTE_FRAG(pages_per_frag);
- uint64_t frag_align = 1 << pages_per_frag;
+ uint64_t frag_align = 1ULL << pages_per_frag;

uint64_t frag_start = ALIGN(start, frag_align);
uint64_t frag_end = end & ~(frag_align - 1);