[PATCH] drm/amdgpu: Fixes uninitialized variable usage in amdgpu_dm_setup_replay

From: Yuran Pereira
Date: Thu Oct 26 2023 - 17:26:09 EST


Since `pr_config` is not initialized after its declaration, the
following operations with `replay_enable_option` may be performed
when `replay_enable_option` is holding junk values which could
possibly lead to undefined behaviour

```
...
pr_config.replay_enable_option |= pr_enable_option_static_screen;
...

if (!pr_config.replay_timing_sync_supported)
pr_config.replay_enable_option &= ~pr_enable_option_general_ui;
...
```

This patch initializes `pr_config` after its declaration to ensure that
it doesn't contain junk data, and prevent any undefined behaviour

Addresses-Coverity-ID: 1544428 ("Uninitialized scalar variable")
Fixes: dede1fea4460 ("drm/amd/display: Add Freesync Panel DM code")
Signed-off-by: Yuran Pereira <yuran.pereira@xxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_replay.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_replay.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_replay.c
index 32d3086c4cb7..40526507f50b 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_replay.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_replay.c
@@ -23,6 +23,7 @@
*
*/

+#include <linux/string.h>
#include "amdgpu_dm_replay.h"
#include "dc.h"
#include "dm_helpers.h"
@@ -74,6 +75,8 @@ bool amdgpu_dm_setup_replay(struct dc_link *link, struct amdgpu_dm_connector *ac
struct replay_config pr_config;
union replay_debug_flags *debug_flags = NULL;

+ memset(&pr_config, 0, sizeof(pr_config));
+
// For eDP, if Replay is supported, return true to skip checks
if (link->replay_settings.config.replay_supported)
return true;
--
2.25.1