drm/amdgpu: move taking mmap_sem into get_user_pages v2

This didn't helped as intended, just simplify the code.

v2: unlock mmap_sem in the error path as well

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 28e121984332..ea0378c8b049 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -622,6 +622,8 @@ 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(&current->mm->mmap_sem);
+
         if (gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) {
                 /* check that we only use anonymous memory
                    to prevent problems with writeback */
@@ -629,8 +631,10 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
                 struct vm_area_struct *vma;
 
                 vma = find_vma(gtt->usermm, gtt->userptr);
-                if (!vma || vma->vm_file || vma->vm_end < end)
+                if (!vma || vma->vm_file || vma->vm_end < end) {
+                        up_read(&current->mm->mmap_sem);
                         return -EPERM;
+                }
         }
 
         do {
@@ -657,10 +661,12 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
 
         } while (pinned < ttm->num_pages);
 
+        up_read(&current->mm->mmap_sem);
         return 0;
 
 release_pages:
         release_pages(pages, pinned, 0);
+        up_read(&current->mm->mmap_sem);
         return r;
 }