From a7c6d986632f84648334937c47ad43fdcbdaa474 Mon Sep 17 00:00:00 2001 From: "Le.Ma" Date: Fri, 22 Sep 2017 10:56:57 +0800 Subject: [PATCH 1812/4131] drm/amdgpu: [KFD] Fix rw_semaphore usage Avoid accessing current pointer in amdgpu_ttm_tt_get_user_pages(), which will cause NULL pointer oops. And remove uneeded rw_semaphore. This fix accords with kfd branch. Change-Id: I0a602b30a20eb444968d6e846f3adca6cfff841a Signed-off-by: Le.Ma Reviewed-by: Junwei Zhang --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 19 +++++-------------- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 8 ++++---- 2 files changed, 9 insertions(+), 18 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c index f5d61eb..8de304b 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c @@ -585,9 +585,7 @@ static int init_user_pages(struct kgd_mem *mem, struct mm_struct *mm, goto unregister_out; } - down_read(&mm->mmap_sem); ret = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm, mem->user_pages); - up_read(&mm->mmap_sem); if (ret) { pr_err("%s: Failed to get user pages: %d\n", __func__, ret); goto free_out; @@ -1961,7 +1959,7 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info, { struct kgd_mem *mem, *tmp_mem; struct amdgpu_bo *bo; - int invalid, ret = 0; + int invalid, ret; /* Move all invalidated BOs to the userptr_inval_list and * release their user pages by migration to the CPU domain @@ -1993,7 +1991,6 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info, return 0; /* All evicted userptr BOs were freed */ /* Go through userptr_inval_list and update any invalid user_pages */ - down_read(&mm->mmap_sem); list_for_each_entry(mem, &process_info->userptr_inval_list, validate_list.head) { invalid = atomic_read(&mem->invalid); @@ -2017,10 +2014,9 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info, GFP_KERNEL | __GFP_ZERO); #endif if (!mem->user_pages) { - ret = -ENOMEM; pr_err("%s: Failed to allocate pages array\n", __func__); - goto unlock_mmap_out; + return -ENOMEM; } } else if (mem->user_pages[0]) { release_pages(mem->user_pages, @@ -2034,7 +2030,6 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info, mem->user_pages[0] = NULL; pr_info("%s: Failed to get user pages: %d\n", __func__, ret); - ret = 0; /* Pretend it succeeded. It will fail later * with a VM fault if the GPU tries to access * it. Better than hanging indefinitely with @@ -2045,14 +2040,10 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info, /* Mark the BO as valid unless it was invalidated * again concurrently */ - if (atomic_cmpxchg(&mem->invalid, invalid, 0) != invalid) { - ret = -EAGAIN; - goto unlock_mmap_out; - } + if (atomic_cmpxchg(&mem->invalid, invalid, 0) != invalid) + return -EAGAIN; } -unlock_mmap_out: - up_read(&mm->mmap_sem); - return ret; + return 0; } /* Validate invalid userptr BOs diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index 8727194..88daa5a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -689,7 +689,7 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages) if (!(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY)) flags |= FOLL_WRITE; - down_read(¤t->mm->mmap_sem); + down_read(&mm->mmap_sem); if (gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) { /* check that we only use anonymous memory @@ -699,7 +699,7 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages) vma = find_vma(mm, gtt->userptr); if (!vma || vma->vm_file || vma->vm_end < end) { - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); return -EPERM; } } @@ -728,12 +728,12 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages) } while (pinned < ttm->num_pages); - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); return 0; release_pages: release_pages(pages, pinned, 0); - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); return r; } -- 2.7.4