[AMD Official Use Only - General]
There was a consensus to use memset instead of {0}. I remember making changes
related to that previously.
Bhawan
________________________________
From: Mahfooz, Hamza <hamza.mahf...@amd.com>
Sent: October 27, 2023 11:53 AM
To: Yuran Pereira <yuran.pere...@hotmail.com>; airl...@gmail.com
<airl...@gmail.com>
Cc: Li, Sun peng (Leo) <sunpeng...@amd.com>; Lakha, Bhawanpreet
<bhawanpreet.la...@amd.com>; Pan, Xinhui <xinhui....@amd.com>; Siqueira,
Rodrigo <rodrigo.sique...@amd.com>; linux-ker...@vger.kernel.org
<linux-ker...@vger.kernel.org>; amd-...@lists.freedesktop.org
<amd-...@lists.freedesktop.org>; dri-devel@lists.freedesktop.org
<dri-devel@lists.freedesktop.org>; Deucher, Alexander
<alexander.deuc...@amd.com>; Koenig, Christian <christian.koe...@amd.com>;
linux-kernel-ment...@lists.linuxfoundation.org
<linux-kernel-ment...@lists.linuxfoundation.org>
Subject: Re: [PATCH] drm/amdgpu: Fixes uninitialized variable usage in
amdgpu_dm_setup_replay
On 10/26/23 17:25, Yuran Pereira wrote:
> 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.pere...@hotmail.com>
> ---
> 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;
I would prefer setting pr_config = {0};
> 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;
--
Hamza
