amdgpu_userq_input_va_validate() converts userq expected_size to page count by right shift.
This undercounts va buffers that less than a page. For example, in the AMDGPU_HW_IP_COMPUTE userq creation case, the expected_size 2048, so size(page count) becomes zero page and the "va_map->last - user_addr + 1 >= size" is always true once the start addr locates in the va_map mapping. A similar case is AMDGPU_HW_IP_DMA, where expected_size is 32. This commit calculates a proper page count by subtracting the start_addr and end_addr in pages. Signed-off-by: Zhu Lingshan <[email protected]> --- drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c index 969f49592450..f9f11bdf2cef 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c @@ -25,6 +25,7 @@ #include <drm/drm_auth.h> #include <drm/drm_exec.h> #include <linux/pm_runtime.h> +#include <linux/overflow.h> #include <drm/drm_drv.h> #include "amdgpu.h" @@ -238,14 +239,21 @@ int amdgpu_userq_input_va_validate(struct amdgpu_device *adev, { struct amdgpu_bo_va_mapping *va_map; struct amdgpu_vm *vm = queue->vm; - u64 user_addr; + u64 user_addr, end; u64 size; /* Caller must hold vm->root.bo reservation */ dma_resv_assert_held(queue->vm->root.bo->tbo.base.resv); - user_addr = (addr & AMDGPU_GMC_HOLE_MASK) >> AMDGPU_GPU_PAGE_SHIFT; - size = expected_size >> AMDGPU_GPU_PAGE_SHIFT; + if (!expected_size) + return -EINVAL; + + user_addr = addr & AMDGPU_GMC_HOLE_MASK; + if (check_add_overflow(user_addr, expected_size - 1, &end)) + return -EINVAL; + + user_addr >>= AMDGPU_GPU_PAGE_SHIFT; + size = (end >> AMDGPU_GPU_PAGE_SHIFT) - user_addr + 1; va_map = amdgpu_vm_bo_lookup_mapping(vm, user_addr); if (!va_map) -- 2.53.0
