[PATCH] drm/amdgpu: disallow multiple BO_HANDLES chunks in one submit

[Pierre-Eric Pelloux-Prayer]

Before this commit, only submits with both a BO_HANDLES chunk and a
'bo_list_handle' would be rejected (by amdgpu_cs_parser_bos).

But if UMD sent a multiple BO_HANDLES, what would happen is:
* only the last one would be really used
* all the others would leak memory as amdgpu_cs_p1_bo_handles would
  overwrite the previous p->bo_list value

This commit rejects submissions with multiple BO_HANDLES chunks to
match the implementation of the parser.

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index c08dfffae262..69d168d6f35a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -154,6 +154,10 @@ static int amdgpu_cs_p1_bo_handles(struct amdgpu_cs_parser *p,
 	struct drm_amdgpu_bo_list_entry *info;
 	int r;
 
+	/* Disallow multiple BO_HANDLES chunks. */
+	if (p->bo_list)
+		return -EINVAL;
+
 	r = amdgpu_bo_create_list_entry_array(data, &info);
 	if (r)
 		return r;
-- 
2.40.1