This patch is a part of a series that extends arm64 kernel ABI to allow to
pass tagged user pointers (with the top byte set to something else other
than 0x00) as syscall arguments.

amdgpu_ttm_tt_get_user_pages() uses provided user pointers for vma
lookups, which can only by done with untagged pointers.

Untag user pointers in this function.

Signed-off-by: Andrey Konovalov <andreyk...@google.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 73e71e61dc99..891b027fa33b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -751,10 +751,11 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, 
struct page **pages)
                 * check that we only use anonymous memory to prevent problems
                 * with writeback
                 */
-               unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
+               unsigned long userptr = untagged_addr(gtt->userptr);
+               unsigned long end = userptr + ttm->num_pages * PAGE_SIZE;
                struct vm_area_struct *vma;
 
-               vma = find_vma(mm, gtt->userptr);
+               vma = find_vma(mm, userptr);
                if (!vma || vma->vm_file || vma->vm_end < end) {
                        up_read(&mm->mmap_sem);
                        return -EPERM;
-- 
2.21.0.225.g810b269d1ac-goog

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