public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
* [PATCH] drm/amd/display: avoid stringop-overflow warnings for dp_decide_lane_settings()
@ 2023-11-22 22:13 Arnd Bergmann
  2023-12-22  5:08 ` Randy Dunlap
  0 siblings, 1 reply; 3+ messages in thread
From: Arnd Bergmann @ 2023-11-22 22:13 UTC (permalink / raw)
  To: Harry Wentland, Leo Li, Rodrigo Siqueira
  Cc: Arnd Bergmann, Alex Deucher, Christian König, Pan, Xinhui,
	David Airlie, Daniel Vetter, Wenjing Liu, Qingqing Zhuo,
	George Shen, Jun Lei, Michael Mityushkin, Srinivasan Shanmugam,
	Alan Liu, Michael Strauss, amd-gfx, dri-devel, linux-kernel

From: Arnd Bergmann <arnd@arndb.de>

gcc prints a warning about a possible array overflow for a couple of
callers of dp_decide_lane_settings() after commit 1b56c90018f0 ("Makefile:
Enable -Wstringop-overflow globally"):

drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c: In function 'dp_perform_fixed_vs_pe_training_sequence_legacy':
drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c:426:25: error: 'dp_decide_lane_settings' accessing 4 bytes in a region of size 1 [-Werror=stringop-overflow=]
  426 |                         dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  427 |                                         lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);
      |                                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c:426:25: note: referencing argument 4 of type 'union dpcd_training_lane[4]'

I'm not entirely sure what caused this, but changing the prototype to expect
a pointer instead of an array avoids the warnings.

Fixes: 7727e7b60f82 ("drm/amd/display: Improve robustness of FIXED_VS link training at DP1 rates")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 .../gpu/drm/amd/display/dc/link/protocols/link_dp_training.c    | 2 +-
 .../gpu/drm/amd/display/dc/link/protocols/link_dp_training.h    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
index 90339c2dfd84..5a0b04518956 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
@@ -807,7 +807,7 @@ void dp_decide_lane_settings(
 		const struct link_training_settings *lt_settings,
 		const union lane_adjust ln_adjust[LANE_COUNT_DP_MAX],
 		struct dc_lane_settings hw_lane_settings[LANE_COUNT_DP_MAX],
-		union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX])
+		union dpcd_training_lane *dpcd_lane_settings)
 {
 	uint32_t lane;
 
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
index 7d027bac8255..851bd17317a0 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
@@ -111,7 +111,7 @@ void dp_decide_lane_settings(
 	const struct link_training_settings *lt_settings,
 	const union lane_adjust ln_adjust[LANE_COUNT_DP_MAX],
 	struct dc_lane_settings hw_lane_settings[LANE_COUNT_DP_MAX],
-	union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX]);
+	union dpcd_training_lane *dpcd_lane_settings);
 
 enum dc_dp_training_pattern decide_cr_training_pattern(
 		const struct dc_link_settings *link_settings);
-- 
2.39.2


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] drm/amd/display: avoid stringop-overflow warnings for dp_decide_lane_settings()
  2023-11-22 22:13 [PATCH] drm/amd/display: avoid stringop-overflow warnings for dp_decide_lane_settings() Arnd Bergmann
@ 2023-12-22  5:08 ` Randy Dunlap
  2024-01-03 14:49   ` Alex Deucher
  0 siblings, 1 reply; 3+ messages in thread
From: Randy Dunlap @ 2023-12-22  5:08 UTC (permalink / raw)
  To: Arnd Bergmann, Harry Wentland, Leo Li, Rodrigo Siqueira
  Cc: Arnd Bergmann, Alex Deucher, Christian König, Pan, Xinhui,
	David Airlie, Daniel Vetter, Wenjing Liu, Qingqing Zhuo,
	George Shen, Jun Lei, Michael Mityushkin, Srinivasan Shanmugam,
	Alan Liu, Michael Strauss, amd-gfx, dri-devel, linux-kernel



On 11/22/23 14:13, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> gcc prints a warning about a possible array overflow for a couple of
> callers of dp_decide_lane_settings() after commit 1b56c90018f0 ("Makefile:
> Enable -Wstringop-overflow globally"):
> 
> drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c: In function 'dp_perform_fixed_vs_pe_training_sequence_legacy':
> drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c:426:25: error: 'dp_decide_lane_settings' accessing 4 bytes in a region of size 1 [-Werror=stringop-overflow=]
>   426 |                         dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
>       |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   427 |                                         lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);
>       |                                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c:426:25: note: referencing argument 4 of type 'union dpcd_training_lane[4]'
> 
> I'm not entirely sure what caused this, but changing the prototype to expect
> a pointer instead of an array avoids the warnings.
> 
> Fixes: 7727e7b60f82 ("drm/amd/display: Improve robustness of FIXED_VS link training at DP1 rates")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>


Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested

Thanks.

> ---
>  .../gpu/drm/amd/display/dc/link/protocols/link_dp_training.c    | 2 +-
>  .../gpu/drm/amd/display/dc/link/protocols/link_dp_training.h    | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
> index 90339c2dfd84..5a0b04518956 100644
> --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
> +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
> @@ -807,7 +807,7 @@ void dp_decide_lane_settings(
>  		const struct link_training_settings *lt_settings,
>  		const union lane_adjust ln_adjust[LANE_COUNT_DP_MAX],
>  		struct dc_lane_settings hw_lane_settings[LANE_COUNT_DP_MAX],
> -		union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX])
> +		union dpcd_training_lane *dpcd_lane_settings)
>  {
>  	uint32_t lane;
>  
> diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
> index 7d027bac8255..851bd17317a0 100644
> --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
> +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
> @@ -111,7 +111,7 @@ void dp_decide_lane_settings(
>  	const struct link_training_settings *lt_settings,
>  	const union lane_adjust ln_adjust[LANE_COUNT_DP_MAX],
>  	struct dc_lane_settings hw_lane_settings[LANE_COUNT_DP_MAX],
> -	union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX]);
> +	union dpcd_training_lane *dpcd_lane_settings);
>  
>  enum dc_dp_training_pattern decide_cr_training_pattern(
>  		const struct dc_link_settings *link_settings);

-- 
#Randy
https://people.kernel.org/tglx/notes-about-netiquette
https://subspace.kernel.org/etiquette.html

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] drm/amd/display: avoid stringop-overflow warnings for dp_decide_lane_settings()
  2023-12-22  5:08 ` Randy Dunlap
@ 2024-01-03 14:49   ` Alex Deucher
  0 siblings, 0 replies; 3+ messages in thread
From: Alex Deucher @ 2024-01-03 14:49 UTC (permalink / raw)
  To: Randy Dunlap
  Cc: Arnd Bergmann, Harry Wentland, Leo Li, Rodrigo Siqueira, Alan Liu,
	Srinivasan Shanmugam, Arnd Bergmann, Qingqing Zhuo, Pan, Xinhui,
	Wenjing Liu, linux-kernel, amd-gfx, Michael Mityushkin,
	Michael Strauss, dri-devel, Daniel Vetter, George Shen,
	Alex Deucher, Jun Lei, David Airlie, Christian König

Applied.  Thanks!

On Mon, Dec 25, 2023 at 5:30 AM Randy Dunlap <rdunlap@infradead.org> wrote:
>
>
>
> On 11/22/23 14:13, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@arndb.de>
> >
> > gcc prints a warning about a possible array overflow for a couple of
> > callers of dp_decide_lane_settings() after commit 1b56c90018f0 ("Makefile:
> > Enable -Wstringop-overflow globally"):
> >
> > drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c: In function 'dp_perform_fixed_vs_pe_training_sequence_legacy':
> > drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c:426:25: error: 'dp_decide_lane_settings' accessing 4 bytes in a region of size 1 [-Werror=stringop-overflow=]
> >   426 |                         dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
> >       |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >   427 |                                         lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);
> >       |                                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c:426:25: note: referencing argument 4 of type 'union dpcd_training_lane[4]'
> >
> > I'm not entirely sure what caused this, but changing the prototype to expect
> > a pointer instead of an array avoids the warnings.
> >
> > Fixes: 7727e7b60f82 ("drm/amd/display: Improve robustness of FIXED_VS link training at DP1 rates")
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>
>
> Acked-by: Randy Dunlap <rdunlap@infradead.org>
> Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
>
> Thanks.
>
> > ---
> >  .../gpu/drm/amd/display/dc/link/protocols/link_dp_training.c    | 2 +-
> >  .../gpu/drm/amd/display/dc/link/protocols/link_dp_training.h    | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
> > index 90339c2dfd84..5a0b04518956 100644
> > --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
> > +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
> > @@ -807,7 +807,7 @@ void dp_decide_lane_settings(
> >               const struct link_training_settings *lt_settings,
> >               const union lane_adjust ln_adjust[LANE_COUNT_DP_MAX],
> >               struct dc_lane_settings hw_lane_settings[LANE_COUNT_DP_MAX],
> > -             union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX])
> > +             union dpcd_training_lane *dpcd_lane_settings)
> >  {
> >       uint32_t lane;
> >
> > diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
> > index 7d027bac8255..851bd17317a0 100644
> > --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
> > +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
> > @@ -111,7 +111,7 @@ void dp_decide_lane_settings(
> >       const struct link_training_settings *lt_settings,
> >       const union lane_adjust ln_adjust[LANE_COUNT_DP_MAX],
> >       struct dc_lane_settings hw_lane_settings[LANE_COUNT_DP_MAX],
> > -     union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX]);
> > +     union dpcd_training_lane *dpcd_lane_settings);
> >
> >  enum dc_dp_training_pattern decide_cr_training_pattern(
> >               const struct dc_link_settings *link_settings);
>
> --
> #Randy
> https://people.kernel.org/tglx/notes-about-netiquette
> https://subspace.kernel.org/etiquette.html

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2024-01-03 14:49 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-11-22 22:13 [PATCH] drm/amd/display: avoid stringop-overflow warnings for dp_decide_lane_settings() Arnd Bergmann
2023-12-22  5:08 ` Randy Dunlap
2024-01-03 14:49   ` Alex Deucher

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox