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* [PATCH] drm/amd/display: Use 2-factor allocator calls
@ 2018-07-04 17:27 Kees Cook
  2018-07-04 17:53   ` Harry Wentland
  2018-07-05 13:37   ` Michel Dänzer
  0 siblings, 2 replies; 7+ messages in thread
From: Kees Cook @ 2018-07-04 17:27 UTC (permalink / raw)
  To: Alex Deucher
  Cc: Vitaly Prosyak, Tony Cheng, Harry Wentland, amd-gfx, dri-devel,
	linux-kernel

As already done treewide, switch from open-coded multiplication to
2-factor allocation helper.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/gpu/drm/amd/display/modules/color/color_gamma.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
index 98edaefa2b47..ee69c949bfbf 100644
--- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
+++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
@@ -1723,8 +1723,8 @@ bool  mod_color_calculate_curve(enum dc_transfer_func_predefined trans,
 		kvfree(rgb_regamma);
 	} else if (trans == TRANSFER_FUNCTION_HLG ||
 		trans == TRANSFER_FUNCTION_HLG12) {
-		rgb_regamma = kvzalloc(sizeof(*rgb_regamma) *
-				       (MAX_HW_POINTS + _EXTRA_POINTS),
+		rgb_regamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
+				       sizeof(*rgb_regamma),
 				       GFP_KERNEL);
 		if (!rgb_regamma)
 			goto rgb_regamma_alloc_fail;
@@ -1802,8 +1802,8 @@ bool  mod_color_calculate_degamma_curve(enum dc_transfer_func_predefined trans,
 		kvfree(rgb_degamma);
 	} else if (trans == TRANSFER_FUNCTION_HLG ||
 		trans == TRANSFER_FUNCTION_HLG12) {
-		rgb_degamma = kvzalloc(sizeof(*rgb_degamma) *
-				       (MAX_HW_POINTS + _EXTRA_POINTS),
+		rgb_degamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
+				       sizeof(*rgb_degamma),
 				       GFP_KERNEL);
 		if (!rgb_degamma)
 			goto rgb_degamma_alloc_fail;
-- 
2.17.1


-- 
Kees Cook
Pixel Security

^ permalink raw reply related	[flat|nested] 7+ messages in thread
* Re: [PATCH] drm/amd/display: Use 2-factor allocator calls
  2018-07-04 17:27 [PATCH] drm/amd/display: Use 2-factor allocator calls Kees Cook
@ 2018-07-04 17:53   ` Harry Wentland
  2018-07-05 13:37   ` Michel Dänzer
  1 sibling, 0 replies; 7+ messages in thread
From: Harry Wentland @ 2018-07-04 17:53 UTC (permalink / raw)
  To: Kees Cook, Alex Deucher
  Cc: Vitaly Prosyak, Tony Cheng, amd-gfx, dri-devel, linux-kernel

On 2018-07-04 01:27 PM, Kees Cook wrote:
> As already done treewide, switch from open-coded multiplication to
> 2-factor allocation helper.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

> ---
>  drivers/gpu/drm/amd/display/modules/color/color_gamma.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> index 98edaefa2b47..ee69c949bfbf 100644
> --- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> +++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> @@ -1723,8 +1723,8 @@ bool  mod_color_calculate_curve(enum dc_transfer_func_predefined trans,
>  		kvfree(rgb_regamma);
>  	} else if (trans == TRANSFER_FUNCTION_HLG ||
>  		trans == TRANSFER_FUNCTION_HLG12) {
> -		rgb_regamma = kvzalloc(sizeof(*rgb_regamma) *
> -				       (MAX_HW_POINTS + _EXTRA_POINTS),
> +		rgb_regamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
> +				       sizeof(*rgb_regamma),
>  				       GFP_KERNEL);
>  		if (!rgb_regamma)
>  			goto rgb_regamma_alloc_fail;
> @@ -1802,8 +1802,8 @@ bool  mod_color_calculate_degamma_curve(enum dc_transfer_func_predefined trans,
>  		kvfree(rgb_degamma);
>  	} else if (trans == TRANSFER_FUNCTION_HLG ||
>  		trans == TRANSFER_FUNCTION_HLG12) {
> -		rgb_degamma = kvzalloc(sizeof(*rgb_degamma) *
> -				       (MAX_HW_POINTS + _EXTRA_POINTS),
> +		rgb_degamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
> +				       sizeof(*rgb_degamma),
>  				       GFP_KERNEL);
>  		if (!rgb_degamma)
>  			goto rgb_degamma_alloc_fail;
> 

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] drm/amd/display: Use 2-factor allocator calls
@ 2018-07-04 17:53   ` Harry Wentland
  0 siblings, 0 replies; 7+ messages in thread
From: Harry Wentland @ 2018-07-04 17:53 UTC (permalink / raw)
  To: Kees Cook, Alex Deucher
  Cc: dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW, Tony Cheng,
	Vitaly Prosyak, amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA

On 2018-07-04 01:27 PM, Kees Cook wrote:
> As already done treewide, switch from open-coded multiplication to
> 2-factor allocation helper.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

> ---
>  drivers/gpu/drm/amd/display/modules/color/color_gamma.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> index 98edaefa2b47..ee69c949bfbf 100644
> --- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> +++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> @@ -1723,8 +1723,8 @@ bool  mod_color_calculate_curve(enum dc_transfer_func_predefined trans,
>  		kvfree(rgb_regamma);
>  	} else if (trans == TRANSFER_FUNCTION_HLG ||
>  		trans == TRANSFER_FUNCTION_HLG12) {
> -		rgb_regamma = kvzalloc(sizeof(*rgb_regamma) *
> -				       (MAX_HW_POINTS + _EXTRA_POINTS),
> +		rgb_regamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
> +				       sizeof(*rgb_regamma),
>  				       GFP_KERNEL);
>  		if (!rgb_regamma)
>  			goto rgb_regamma_alloc_fail;
> @@ -1802,8 +1802,8 @@ bool  mod_color_calculate_degamma_curve(enum dc_transfer_func_predefined trans,
>  		kvfree(rgb_degamma);
>  	} else if (trans == TRANSFER_FUNCTION_HLG ||
>  		trans == TRANSFER_FUNCTION_HLG12) {
> -		rgb_degamma = kvzalloc(sizeof(*rgb_degamma) *
> -				       (MAX_HW_POINTS + _EXTRA_POINTS),
> +		rgb_degamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
> +				       sizeof(*rgb_degamma),
>  				       GFP_KERNEL);
>  		if (!rgb_degamma)
>  			goto rgb_degamma_alloc_fail;
> 
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] drm/amd/display: Use 2-factor allocator calls
  2018-07-04 17:27 [PATCH] drm/amd/display: Use 2-factor allocator calls Kees Cook
@ 2018-07-05 13:37   ` Michel Dänzer
  2018-07-05 13:37   ` Michel Dänzer
  1 sibling, 0 replies; 7+ messages in thread
From: Michel Dänzer @ 2018-07-05 13:37 UTC (permalink / raw)
  To: Kees Cook, Alex Deucher
  Cc: amd-gfx, Tony Cheng, linux-kernel, dri-devel, Vitaly Prosyak,
	Harry Wentland

On 2018-07-04 07:27 PM, Kees Cook wrote:
> As already done treewide, switch from open-coded multiplication to
> 2-factor allocation helper.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  drivers/gpu/drm/amd/display/modules/color/color_gamma.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> index 98edaefa2b47..ee69c949bfbf 100644
> --- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> +++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> @@ -1723,8 +1723,8 @@ bool  mod_color_calculate_curve(enum dc_transfer_func_predefined trans,
>  		kvfree(rgb_regamma);
>  	} else if (trans == TRANSFER_FUNCTION_HLG ||
>  		trans == TRANSFER_FUNCTION_HLG12) {
> -		rgb_regamma = kvzalloc(sizeof(*rgb_regamma) *
> -				       (MAX_HW_POINTS + _EXTRA_POINTS),
> +		rgb_regamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
> +				       sizeof(*rgb_regamma),
>  				       GFP_KERNEL);
>  		if (!rgb_regamma)
>  			goto rgb_regamma_alloc_fail;
> @@ -1802,8 +1802,8 @@ bool  mod_color_calculate_degamma_curve(enum dc_transfer_func_predefined trans,
>  		kvfree(rgb_degamma);
>  	} else if (trans == TRANSFER_FUNCTION_HLG ||
>  		trans == TRANSFER_FUNCTION_HLG12) {
> -		rgb_degamma = kvzalloc(sizeof(*rgb_degamma) *
> -				       (MAX_HW_POINTS + _EXTRA_POINTS),
> +		rgb_degamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
> +				       sizeof(*rgb_degamma),
>  				       GFP_KERNEL);
>  		if (!rgb_degamma)
>  			goto rgb_degamma_alloc_fail;
> 

Since the values are constant, kvcalloc incurs the overflow checking
overhead for no gain.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] drm/amd/display: Use 2-factor allocator calls
@ 2018-07-05 13:37   ` Michel Dänzer
  0 siblings, 0 replies; 7+ messages in thread
From: Michel Dänzer @ 2018-07-05 13:37 UTC (permalink / raw)
  To: Kees Cook, Alex Deucher
  Cc: Tony Cheng, linux-kernel, dri-devel, amd-gfx, Vitaly Prosyak

On 2018-07-04 07:27 PM, Kees Cook wrote:
> As already done treewide, switch from open-coded multiplication to
> 2-factor allocation helper.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  drivers/gpu/drm/amd/display/modules/color/color_gamma.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> index 98edaefa2b47..ee69c949bfbf 100644
> --- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> +++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
> @@ -1723,8 +1723,8 @@ bool  mod_color_calculate_curve(enum dc_transfer_func_predefined trans,
>  		kvfree(rgb_regamma);
>  	} else if (trans == TRANSFER_FUNCTION_HLG ||
>  		trans == TRANSFER_FUNCTION_HLG12) {
> -		rgb_regamma = kvzalloc(sizeof(*rgb_regamma) *
> -				       (MAX_HW_POINTS + _EXTRA_POINTS),
> +		rgb_regamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
> +				       sizeof(*rgb_regamma),
>  				       GFP_KERNEL);
>  		if (!rgb_regamma)
>  			goto rgb_regamma_alloc_fail;
> @@ -1802,8 +1802,8 @@ bool  mod_color_calculate_degamma_curve(enum dc_transfer_func_predefined trans,
>  		kvfree(rgb_degamma);
>  	} else if (trans == TRANSFER_FUNCTION_HLG ||
>  		trans == TRANSFER_FUNCTION_HLG12) {
> -		rgb_degamma = kvzalloc(sizeof(*rgb_degamma) *
> -				       (MAX_HW_POINTS + _EXTRA_POINTS),
> +		rgb_degamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
> +				       sizeof(*rgb_degamma),
>  				       GFP_KERNEL);
>  		if (!rgb_degamma)
>  			goto rgb_degamma_alloc_fail;
> 

Since the values are constant, kvcalloc incurs the overflow checking
overhead for no gain.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] drm/amd/display: Use 2-factor allocator calls
  2018-07-05 13:37   ` Michel Dänzer
@ 2018-07-05 15:55     ` Kees Cook
  -1 siblings, 0 replies; 7+ messages in thread
From: Kees Cook @ 2018-07-05 15:55 UTC (permalink / raw)
  To: Michel Dänzer
  Cc: Alex Deucher, amd-gfx list, Tony Cheng, LKML,
	Maling list - DRI developers, Vitaly Prosyak, Harry Wentland

On Thu, Jul 5, 2018 at 6:37 AM, Michel Dänzer <michel@daenzer.net> wrote:
> On 2018-07-04 07:27 PM, Kees Cook wrote:
>> As already done treewide, switch from open-coded multiplication to
>> 2-factor allocation helper.
>>
>> Signed-off-by: Kees Cook <keescook@chromium.org>
>> ---
>>  drivers/gpu/drm/amd/display/modules/color/color_gamma.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
>> index 98edaefa2b47..ee69c949bfbf 100644
>> --- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
>> +++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
>> @@ -1723,8 +1723,8 @@ bool  mod_color_calculate_curve(enum dc_transfer_func_predefined trans,
>>               kvfree(rgb_regamma);
>>       } else if (trans == TRANSFER_FUNCTION_HLG ||
>>               trans == TRANSFER_FUNCTION_HLG12) {
>> -             rgb_regamma = kvzalloc(sizeof(*rgb_regamma) *
>> -                                    (MAX_HW_POINTS + _EXTRA_POINTS),
>> +             rgb_regamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
>> +                                    sizeof(*rgb_regamma),
>>                                      GFP_KERNEL);
>>               if (!rgb_regamma)
>>                       goto rgb_regamma_alloc_fail;
>> @@ -1802,8 +1802,8 @@ bool  mod_color_calculate_degamma_curve(enum dc_transfer_func_predefined trans,
>>               kvfree(rgb_degamma);
>>       } else if (trans == TRANSFER_FUNCTION_HLG ||
>>               trans == TRANSFER_FUNCTION_HLG12) {
>> -             rgb_degamma = kvzalloc(sizeof(*rgb_degamma) *
>> -                                    (MAX_HW_POINTS + _EXTRA_POINTS),
>> +             rgb_degamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
>> +                                    sizeof(*rgb_degamma),
>>                                      GFP_KERNEL);
>>               if (!rgb_degamma)
>>                       goto rgb_degamma_alloc_fail;
>>
>
> Since the values are constant, kvcalloc incurs the overflow checking
> overhead for no gain.

The way the macros are designed, they'll get entirely optimized away
in that case:
http://lkml.kernel.org/r/CAGXu5jLw9kMZRkzL_Q7JdyyprntHF6bdVSE_vjyzect3CenDng@mail.gmail.com

Using this patch means if the code ever changes away from constants,
it'll still be safe. And static checkers won't yell about the
open-coded multiplication here. So it's only up-sides. :)

-Kees

-- 
Kees Cook
Pixel Security

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] drm/amd/display: Use 2-factor allocator calls
@ 2018-07-05 15:55     ` Kees Cook
  0 siblings, 0 replies; 7+ messages in thread
From: Kees Cook @ 2018-07-05 15:55 UTC (permalink / raw)
  To: Michel Dänzer
  Cc: Alex Deucher, amd-gfx list, Tony Cheng, LKML,
	Maling list - DRI developers, Vitaly Prosyak, Harry Wentland

On Thu, Jul 5, 2018 at 6:37 AM, Michel Dänzer <michel@daenzer.net> wrote:
> On 2018-07-04 07:27 PM, Kees Cook wrote:
>> As already done treewide, switch from open-coded multiplication to
>> 2-factor allocation helper.
>>
>> Signed-off-by: Kees Cook <keescook@chromium.org>
>> ---
>>  drivers/gpu/drm/amd/display/modules/color/color_gamma.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
>> index 98edaefa2b47..ee69c949bfbf 100644
>> --- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
>> +++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
>> @@ -1723,8 +1723,8 @@ bool  mod_color_calculate_curve(enum dc_transfer_func_predefined trans,
>>               kvfree(rgb_regamma);
>>       } else if (trans == TRANSFER_FUNCTION_HLG ||
>>               trans == TRANSFER_FUNCTION_HLG12) {
>> -             rgb_regamma = kvzalloc(sizeof(*rgb_regamma) *
>> -                                    (MAX_HW_POINTS + _EXTRA_POINTS),
>> +             rgb_regamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
>> +                                    sizeof(*rgb_regamma),
>>                                      GFP_KERNEL);
>>               if (!rgb_regamma)
>>                       goto rgb_regamma_alloc_fail;
>> @@ -1802,8 +1802,8 @@ bool  mod_color_calculate_degamma_curve(enum dc_transfer_func_predefined trans,
>>               kvfree(rgb_degamma);
>>       } else if (trans == TRANSFER_FUNCTION_HLG ||
>>               trans == TRANSFER_FUNCTION_HLG12) {
>> -             rgb_degamma = kvzalloc(sizeof(*rgb_degamma) *
>> -                                    (MAX_HW_POINTS + _EXTRA_POINTS),
>> +             rgb_degamma = kvcalloc(MAX_HW_POINTS + _EXTRA_POINTS,
>> +                                    sizeof(*rgb_degamma),
>>                                      GFP_KERNEL);
>>               if (!rgb_degamma)
>>                       goto rgb_degamma_alloc_fail;
>>
>
> Since the values are constant, kvcalloc incurs the overflow checking
> overhead for no gain.

The way the macros are designed, they'll get entirely optimized away
in that case:
http://lkml.kernel.org/r/CAGXu5jLw9kMZRkzL_Q7JdyyprntHF6bdVSE_vjyzect3CenDng@mail.gmail.com

Using this patch means if the code ever changes away from constants,
it'll still be safe. And static checkers won't yell about the
open-coded multiplication here. So it's only up-sides. :)

-Kees

-- 
Kees Cook
Pixel Security

^ permalink raw reply	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2018-07-05 15:55 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-07-04 17:27 [PATCH] drm/amd/display: Use 2-factor allocator calls Kees Cook
2018-07-04 17:53 ` Harry Wentland
2018-07-04 17:53   ` Harry Wentland
2018-07-05 13:37 ` Michel Dänzer
2018-07-05 13:37   ` Michel Dänzer
2018-07-05 15:55   ` Kees Cook
2018-07-05 15:55     ` Kees Cook

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