Hello,
On Fri, Oct 27, 2023 at 11:57:45AM -0400, Hamza Mahfooz wrote:
> On 10/27/23 11:55, Lakha, Bhawanpreet wrote:
> > [AMD Official Use Only - General]
> >
> >
> >
> > There was a consensus to use memset instead of {0}. I remember making
> > changes related to that previously.
>
> Hm, seems like it's used rather consistently in the DM and in DC
> though.
>
Have you decided which one should be used?
Should I submit a v2 patch using {0} instead of memset?
Yuran Pereira
> >
> > Bhawan
> >
> > ------------------------------------------------------------------------
> > *From:* Mahfooz, Hamza <Hamza.Mahfooz@xxxxxxx>
> > *Sent:* October 27, 2023 11:53 AM
> > *To:* Yuran Pereira <yuran.pereira@xxxxxxxxxxx>; airlied@xxxxxxxxx
> > <airlied@xxxxxxxxx>
> > *Cc:* Li, Sun peng (Leo) <Sunpeng.Li@xxxxxxx>; Lakha, Bhawanpreet
> > <Bhawanpreet.Lakha@xxxxxxx>; Pan, Xinhui <Xinhui.Pan@xxxxxxx>; Siqueira,
> > Rodrigo <Rodrigo.Siqueira@xxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx
> > <linux-kernel@xxxxxxxxxxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> > <amd-gfx@xxxxxxxxxxxxxxxxxxxxx>; dri-devel@xxxxxxxxxxxxxxxxxxxxx
> > <dri-devel@xxxxxxxxxxxxxxxxxxxxx>; Deucher, Alexander
> > <Alexander.Deucher@xxxxxxx>; Koenig, Christian
> > <Christian.Koenig@xxxxxxx>;
> > linux-kernel-mentees@xxxxxxxxxxxxxxxxxxxxxxxxx
> > <linux-kernel-mentees@xxxxxxxxxxxxxxxxxxxxxxxxx>
> > *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.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;
> >
> > 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
> >
> --
> Hamza
>
