Thread (22 messages) 22 messages, 2 authors, 2019-03-21
STALE2610d
Revisions (4)
  1. v13 current
  2. v14 [diff vs current]
  3. v15 [diff vs current]
  4. v16 [diff vs current]

[PATCH v13 15/20] drm/radeon, arm64: untag user pointers in radeon_ttm_tt_pin_userptr

From: Andrey Konovalov <hidden>
Date: 2019-03-20 14:53:43
Also in: bpf, linux-arch, linux-kselftest, linux-media, linux-mm, lkml
Subsystem: drm drivers, radeon and amdgpu drm drivers, the rest · Maintainers: David Airlie, Simona Vetter, Alex Deucher, Christian König, Linus Torvalds

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.

radeon_ttm_tt_pin_userptr() 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 <redacted>
---
 drivers/gpu/drm/radeon/radeon_ttm.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index 9920a6fc11bf..872a98796117 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -497,9 +497,10 @@ static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)
 	if (gtt->userflags & RADEON_GEM_USERPTR_ANONONLY) {
 		/* check that we only pin down 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(gtt->usermm, gtt->userptr);
+		vma = find_vma(gtt->usermm, userptr);
 		if (!vma || vma->vm_file || vma->vm_end < end)
 			return -EPERM;
 	}
-- 
2.21.0.225.g810b269d1ac-goog
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