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

2023-10-30 Thread Christian König 

Am 28.10.23 um 02:48 schrieb Yuran Pereira:

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?


The problem is that {0} doesn't initialize padding fields in structures.

So what can happen are problems like leaking bytes to userspace or 
getting unstable hash keys etc...


So I think memset() is usually preferred and that not only counts for Linux.

Regards,
Christian.




Yuran Pereira

Bhawan


*From:* Mahfooz, Hamza 
*Sent:* October 27, 2023 11:53 AM
*To:* Yuran Pereira ; airl...@gmail.com

*Cc:* Li, Sun peng (Leo) ; Lakha, Bhawanpreet
; Pan, Xinhui ; Siqueira,
Rodrigo ; linux-ker...@vger.kernel.org
; amd-...@lists.freedesktop.org
; dri-devel@lists.freedesktop.org
; Deucher, Alexander
; Koenig, Christian
;
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 
---
    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 
    #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(_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

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

2023-10-27 Thread Yuran Pereira 
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 
> > *Sent:* October 27, 2023 11:53 AM
> > *To:* Yuran Pereira ; airl...@gmail.com
> > 
> > *Cc:* Li, Sun peng (Leo) ; Lakha, Bhawanpreet
> > ; Pan, Xinhui ; Siqueira,
> > Rodrigo ; linux-ker...@vger.kernel.org
> > ; amd-...@lists.freedesktop.org
> > ; dri-devel@lists.freedesktop.org
> > ; Deucher, Alexander
> > ; Koenig, Christian
> > ;
> > 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 
> > > ---
> > >    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 
> > >    #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(_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
>

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

2023-10-27 Thread Hamza Mahfooz 

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.



Bhawan


*From:* Mahfooz, Hamza 
*Sent:* October 27, 2023 11:53 AM
*To:* Yuran Pereira ; airl...@gmail.com 

*Cc:* Li, Sun peng (Leo) ; Lakha, Bhawanpreet 
; Pan, Xinhui ; Siqueira, 
Rodrigo ; linux-ker...@vger.kernel.org 
; amd-...@lists.freedesktop.org 
; dri-devel@lists.freedesktop.org 
; Deucher, Alexander 
; Koenig, Christian 
; 
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 
---
   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 

   #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(_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

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

2023-10-27 Thread Lakha, Bhawanpreet 
[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 
Sent: October 27, 2023 11:53 AM
To: Yuran Pereira ; airl...@gmail.com 

Cc: Li, Sun peng (Leo) ; Lakha, Bhawanpreet 
; Pan, Xinhui ; Siqueira, 
Rodrigo ; linux-ker...@vger.kernel.org 
; amd-...@lists.freedesktop.org 
; dri-devel@lists.freedesktop.org 
; Deucher, Alexander 
; Koenig, Christian ; 
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 
> ---
>   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 
>   #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(_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

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

2023-10-27 Thread Hamza Mahfooz 

Also, please write the tagline in present tense.
On 10/27/23 11:53, Hamza Mahfooz wrote:

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 
---
  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 
  #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(_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

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

2023-10-27 Thread Hamza Mahfooz 

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 
---
  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 

  #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(_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

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

2023-10-27 Thread Lakha, Bhawanpreet 
[AMD Official Use Only - General]

Thanks,

Reviewed-by: Bhawanpreet Lakha 


From: Yuran Pereira 
Sent: October 26, 2023 5:25 PM
To: airl...@gmail.com 
Cc: Yuran Pereira ; Wentland, Harry 
; Li, Sun peng (Leo) ; Siqueira, 
Rodrigo ; Deucher, Alexander 
; Koenig, Christian ; Pan, 
Xinhui ; dan...@ffwll.ch ; Lakha, 
Bhawanpreet ; amd-...@lists.freedesktop.org 
; dri-devel@lists.freedesktop.org 
; linux-ker...@vger.kernel.org 
; linux-kernel-ment...@lists.linuxfoundation.org 

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

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 
---
 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 
 #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(_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

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

2023-10-26 Thread Yuran Pereira 
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 
---
 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 
 #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(_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