[PATCH v3] drm/amdgpu: Fix size validation for non-exclusive domains (v3)

[Luben Tuikov]

Fix amdgpu_bo_validate_size() to check whether the TTM domain manager for the
requested memory exists, else we get a kernel oops when dereferencing "man".

v2: Make the patch standalone, i.e. not dependent on local patches.
v3: Preserve old behaviour and just check that the manager pointer is not
    NULL.

Cc: Alex Deucher <Alexander.Deucher at amd.com>
Cc: Christian König <christian.koenig at amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index fd3ab4b5e5bb1f..43b01f8287ea52 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -448,12 +448,12 @@ static bool amdgpu_bo_validate_size(struct amdgpu_device *adev,
 
 	/*
 	 * If GTT is part of requested domains the check must succeed to
-	 * allow fall back to GTT
+	 * allow fall back to GTT.
 	 */
 	if (domain & AMDGPU_GEM_DOMAIN_GTT) {
 		man = ttm_manager_type(&adev->mman.bdev, TTM_PL_TT);
 
-		if (size < man->size)
+		if (man && size < man->size)
 			return true;
 		else
 			goto fail;
@@ -462,13 +462,12 @@ static bool amdgpu_bo_validate_size(struct amdgpu_device *adev,
 	if (domain & AMDGPU_GEM_DOMAIN_VRAM) {
 		man = ttm_manager_type(&adev->mman.bdev, TTM_PL_VRAM);
 
-		if (size < man->size)
+		if (man && size < man->size)
 			return true;
 		else
 			goto fail;
 	}
 
-
 	/* TODO add more domains checks, such as AMDGPU_GEM_DOMAIN_CPU */
 	return true;
 

base-commit: 814a56e6601ce866638d4ef005f099119bee39e8
-- 
2.39.0.rc2