drm/amdgpu: Remove hidden double memset from amdgpu_cs_ioctl()

Commit Message

Tvrtko Ursulin Aug. 13, 2024, 2:03 p.m. UTC

From: Tvrtko Ursulin <[e-mail]>

When CONFIG_INIT_STACK_ALL_ZERO is set and so -ftrivial-auto-var-init=zero
compiler option active, compiler fails to notice that inside
amdgpu_cs_parser_init() there is a second memset to clear the same on
stack struct amdgpu_cs_parser.

If we pull this memset one level out, into the amdgpu_cs_ioctl(), compiler
can then see it and avoid clearing this struct twice.

Signed-off-by: Tvrtko Ursulin <[e-mail]>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 9aa952f258cf..554289eb1913 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -51,7 +51,6 @@  static int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p,
 	if (cs->in.num_chunks == 0)
 		return -EINVAL;
 
-	memset(p, 0, sizeof(*p));
 	p->adev = adev;
 	p->filp = filp;
 
@@ -1411,6 +1410,7 @@  int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 	if (!adev->accel_working)
 		return -EBUSY;
 
+	memset(&parser, 0, sizeof(parser));
 	r = amdgpu_cs_parser_init(&parser, adev, filp, data);
 	if (r) {
 		DRM_ERROR_RATELIMITED("Failed to initialize parser %d!\n", r);