diff mbox series

drm/amd/pm: avoid large variable on kernel stack

Message ID	20221215163649.386750-1-arnd@kernel.org
State	New
Headers	Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; From: Arnd Bergmann <arnd@kernel.org> To: Evan Quan <evan.quan@amd.com>, Alex Deucher <alexander.deucher@amd.com>, =?utf-8?q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>, "Pan, Xinhui" <Xinhui.Pan@amd.com> Cc: Arnd Bergmann <arnd@arndb.de>, David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>, Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, Tom Rix <trix@redhat.com>, Kenneth Feng <kenneth.feng@amd.com>, Hawking Zhang <Hawking.Zhang@amd.com>, Yang Wang <KevinYang.Wang@amd.com>, Chengming Gui <Jack.Gui@amd.com>, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH] drm/amd/pm: avoid large variable on kernel stack Date: Thu, 15 Dec 2022 17:36:31 +0100 Message-Id: <20221215163649.386750-1-arnd@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	drm/amd/pm: avoid large variable on kernel stack \| drm/amd/pm: avoid large variable on kernel stack

Commit Message

Arnd Bergmann Dec. 15, 2022, 4:36 p.m. UTC

  From: Arnd Bergmann <arnd@arndb.de>

The activity_monitor_external[] array is too big to fit on the
kernel stack, resulting in this warning with clang:

drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu13/smu_v13_0_7_ppt.c:1438:12: error: stack frame size (1040) exceeds limit (1024) in 'smu_v13_0_7_get_power_profile_mode' [-Werror,-Wframe-larger-than]

Use dynamic allocation instead. It should also be possible to
have single element here instead of the array, but this seems
easier.

Fixes: 334682ae8151 ("drm/amd/pm: enable workload type change on smu_v13_0_7")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 .../drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c  | 21 ++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

Comments

Alex Deucher Dec. 15, 2022, 6:45 p.m. UTC | #1

Applied.  Thanks!

Alex

On Thu, Dec 15, 2022 at 11:37 AM Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> The activity_monitor_external[] array is too big to fit on the
> kernel stack, resulting in this warning with clang:
>
> drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu13/smu_v13_0_7_ppt.c:1438:12: error: stack frame size (1040) exceeds limit (1024) in 'smu_v13_0_7_get_power_profile_mode' [-Werror,-Wframe-larger-than]
>
> Use dynamic allocation instead. It should also be possible to
> have single element here instead of the array, but this seems
> easier.
>
> Fixes: 334682ae8151 ("drm/amd/pm: enable workload type change on smu_v13_0_7")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  .../drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c  | 21 ++++++++++++++-----
>  1 file changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
> index c270f94a1b86..7eba854e09ec 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
> @@ -1439,7 +1439,7 @@ static int smu_v13_0_7_get_power_limit(struct smu_context *smu,
>
>  static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf)
>  {
> -       DpmActivityMonitorCoeffIntExternal_t activity_monitor_external[PP_SMC_POWER_PROFILE_COUNT];
> +       DpmActivityMonitorCoeffIntExternal_t *activity_monitor_external;
>         uint32_t i, j, size = 0;
>         int16_t workload_type = 0;
>         int result = 0;
> @@ -1447,6 +1447,12 @@ static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf
>         if (!buf)
>                 return -EINVAL;
>
> +       activity_monitor_external = kcalloc(sizeof(activity_monitor_external),
> +                                           PP_SMC_POWER_PROFILE_COUNT,
> +                                           GFP_KERNEL);
> +       if (!activity_monitor_external)
> +               return -ENOMEM;
> +
>         size += sysfs_emit_at(buf, size, "                              ");
>         for (i = 0; i <= PP_SMC_POWER_PROFILE_WINDOW3D; i++)
>                 size += sysfs_emit_at(buf, size, "%-14s%s", amdgpu_pp_profile_name[i],
> @@ -1459,15 +1465,17 @@ static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf
>                 workload_type = smu_cmn_to_asic_specific_index(smu,
>                                                                CMN2ASIC_MAPPING_WORKLOAD,
>                                                                i);
> -               if (workload_type < 0)
> -                       return -EINVAL;
> +               if (workload_type < 0) {
> +                       result = -EINVAL;
> +                       goto out;
> +               }
>
>                 result = smu_cmn_update_table(smu,
>                                           SMU_TABLE_ACTIVITY_MONITOR_COEFF, workload_type,
>                                           (void *)(&activity_monitor_external[i]), false);
>                 if (result) {
>                         dev_err(smu->adev->dev, "[%s] Failed to get activity monitor!", __func__);
> -                       return result;
> +                       goto out;
>                 }
>         }
>
> @@ -1495,7 +1503,10 @@ do {                                                                                                     \
>         PRINT_DPM_MONITOR(Fclk_BoosterFreq);
>  #undef PRINT_DPM_MONITOR
>
> -       return size;
> +       result = size;
> +out:
> +       kfree(activity_monitor_external);
> +       return result;
>  }
>
>  static int smu_v13_0_7_set_power_profile_mode(struct smu_context *smu, long *input, uint32_t size)
> --
> 2.35.1
>

Christophe JAILLET Dec. 15, 2022, 7:46 p.m. UTC | #2

Le 15/12/2022 à 17:36, Arnd Bergmann a écrit :
> From: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
> 
> The activity_monitor_external[] array is too big to fit on the
> kernel stack, resulting in this warning with clang:
> 
> drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu13/smu_v13_0_7_ppt.c:1438:12: error: stack frame size (1040) exceeds limit (1024) in 'smu_v13_0_7_get_power_profile_mode' [-Werror,-Wframe-larger-than]
> 
> Use dynamic allocation instead. It should also be possible to
> have single element here instead of the array, but this seems
> easier.
> 
> Fixes: 334682ae8151 ("drm/amd/pm: enable workload type change on smu_v13_0_7")
> Signed-off-by: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
> ---
>   .../drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c  | 21 ++++++++++++++-----
>   1 file changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
> index c270f94a1b86..7eba854e09ec 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
> @@ -1439,7 +1439,7 @@ static int smu_v13_0_7_get_power_limit(struct smu_context *smu,
>   
>   static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf)
>   {
> -	DpmActivityMonitorCoeffIntExternal_t activity_monitor_external[PP_SMC_POWER_PROFILE_COUNT];
> +	DpmActivityMonitorCoeffIntExternal_t *activity_monitor_external;
>   	uint32_t i, j, size = 0;
>   	int16_t workload_type = 0;
>   	int result = 0;
> @@ -1447,6 +1447,12 @@ static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf
>   	if (!buf)
>   		return -EINVAL;
>   
> +	activity_monitor_external = kcalloc(sizeof(activity_monitor_external),

Hi,

Before, 'activity_monitor_external' was not initialized.
Maybe kcalloc() is enough?

sizeof(*activity_monitor_external)?
      ~~~~

> +					    PP_SMC_POWER_PROFILE_COUNT,
> +					    GFP_KERNEL);
> +	if (!activity_monitor_external)
> +		return -ENOMEM;
> +
>   	size += sysfs_emit_at(buf, size, "                              ");
>   	for (i = 0; i <= PP_SMC_POWER_PROFILE_WINDOW3D; i++)

Unrelated, but wouldn't it be more straightforward with "< 
PP_SMC_POWER_PROFILE_COUNT"?

>   		size += sysfs_emit_at(buf, size, "%-14s%s", amdgpu_pp_profile_name[i],
> @@ -1459,15 +1465,17 @@ static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf
>   		workload_type = smu_cmn_to_asic_specific_index(smu,
>   							       CMN2ASIC_MAPPING_WORKLOAD,
>   							       i);
> -		if (workload_type < 0)
> -			return -EINVAL;
> +		if (workload_type < 0) {
> +			result = -EINVAL;
> +			goto out;
> +		}
>   
>   		result = smu_cmn_update_table(smu,
>   					  SMU_TABLE_ACTIVITY_MONITOR_COEFF, workload_type,
>   					  (void *)(&activity_monitor_external[i]), false);
>   		if (result) {
>   			dev_err(smu->adev->dev, "[%s] Failed to get activity monitor!", __func__);
> -			return result;
> +			goto out;
>   		}
>   	}
>   
> @@ -1495,7 +1503,10 @@ do {													\
>   	PRINT_DPM_MONITOR(Fclk_BoosterFreq);
>   #undef PRINT_DPM_MONITOR
>   
> -	return size;
> +	result = size;
> +out:
> +	kfree(activity_monitor_external);
> +	return result;
>   }
>   
>   static int smu_v13_0_7_set_power_profile_mode(struct smu_context *smu, long *input, uint32_t size)

Christophe JAILLET Dec. 15, 2022, 7:49 p.m. UTC | #3

Le 15/12/2022 à 20:46, Christophe JAILLET a écrit :
> Le 15/12/2022 à 17:36, Arnd Bergmann a écrit :
>> From: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
>>
>> The activity_monitor_external[] array is too big to fit on the
>> kernel stack, resulting in this warning with clang:
>>
>> drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu13/smu_v13_0_7_ppt.c:1438:12: error: stack frame size (1040) exceeds limit (1024) in 'smu_v13_0_7_get_power_profile_mode' [-Werror,-Wframe-larger-than]
>>
>> Use dynamic allocation instead. It should also be possible to
>> have single element here instead of the array, but this seems
>> easier.
>>
>> Fixes: 334682ae8151 ("drm/amd/pm: enable workload type change on 
>> smu_v13_0_7")
>> Signed-off-by: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
>> ---
>>   .../drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c  | 21 ++++++++++++++-----
>>   1 file changed, 16 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c 
>> b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
>> index c270f94a1b86..7eba854e09ec 100644
>> --- a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
>> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
>> @@ -1439,7 +1439,7 @@ static int smu_v13_0_7_get_power_limit(struct 
>> smu_context *smu,
>>   static int smu_v13_0_7_get_power_profile_mode(struct smu_context 
>> *smu, char *buf)
>>   {
>> -    DpmActivityMonitorCoeffIntExternal_t 
>> activity_monitor_external[PP_SMC_POWER_PROFILE_COUNT];
>> +    DpmActivityMonitorCoeffIntExternal_t *activity_monitor_external;
>>       uint32_t i, j, size = 0;
>>       int16_t workload_type = 0;
>>       int result = 0;
>> @@ -1447,6 +1447,12 @@ static int 
>> smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf
>>       if (!buf)
>>           return -EINVAL;
>> +    activity_monitor_external = 
>> kcalloc(sizeof(activity_monitor_external),
> 
> Hi,
> 
> Before, 'activity_monitor_external' was not initialized.
> Maybe kcalloc() is enough?

Read kmalloc_array()

> 
> sizeof(*activity_monitor_external)?
>       ~~~~
> 
>> +                        PP_SMC_POWER_PROFILE_COUNT,
>> +                        GFP_KERNEL);
>> +    if (!activity_monitor_external)
>> +        return -ENOMEM;
>> +
>>       size += sysfs_emit_at(buf, size, "                              ");
>>       for (i = 0; i <= PP_SMC_POWER_PROFILE_WINDOW3D; i++)
> 
> Unrelated, but wouldn't it be more straightforward with "< 
> PP_SMC_POWER_PROFILE_COUNT"?
> 
>>           size += sysfs_emit_at(buf, size, "%-14s%s", 
>> amdgpu_pp_profile_name[i],
>> @@ -1459,15 +1465,17 @@ static int 
>> smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf
>>           workload_type = smu_cmn_to_asic_specific_index(smu,
>>                                      CMN2ASIC_MAPPING_WORKLOAD,
>>                                      i);
>> -        if (workload_type < 0)
>> -            return -EINVAL;
>> +        if (workload_type < 0) {
>> +            result = -EINVAL;
>> +            goto out;
>> +        }
>>           result = smu_cmn_update_table(smu,
>>                         SMU_TABLE_ACTIVITY_MONITOR_COEFF, workload_type,
>>                         (void *)(&activity_monitor_external[i]), false);
>>           if (result) {
>>               dev_err(smu->adev->dev, "[%s] Failed to get activity 
>> monitor!", __func__);
>> -            return result;
>> +            goto out;
>>           }
>>       }
>> @@ -1495,7 +1503,10 @@ do 
>> {                                                    \
>>       PRINT_DPM_MONITOR(Fclk_BoosterFreq);
>>   #undef PRINT_DPM_MONITOR
>> -    return size;
>> +    result = size;
>> +out:
>> +    kfree(activity_monitor_external);
>> +    return result;
>>   }
>>   static int smu_v13_0_7_set_power_profile_mode(struct smu_context 
>> *smu, long *input, uint32_t size)
> 
>

Alex Deucher Dec. 16, 2022, 6:24 p.m. UTC | #4

On Thu, Dec 15, 2022 at 2:46 PM Christophe JAILLET
<christophe.jaillet@wanadoo.fr> wrote:
>
> Le 15/12/2022 à 17:36, Arnd Bergmann a écrit :
> > From: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
> >
> > The activity_monitor_external[] array is too big to fit on the
> > kernel stack, resulting in this warning with clang:
> >
> > drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu13/smu_v13_0_7_ppt.c:1438:12: error: stack frame size (1040) exceeds limit (1024) in 'smu_v13_0_7_get_power_profile_mode' [-Werror,-Wframe-larger-than]
> >
> > Use dynamic allocation instead. It should also be possible to
> > have single element here instead of the array, but this seems
> > easier.
> >
> > Fixes: 334682ae8151 ("drm/amd/pm: enable workload type change on smu_v13_0_7")
> > Signed-off-by: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
> > ---
> >   .../drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c  | 21 ++++++++++++++-----
> >   1 file changed, 16 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
> > index c270f94a1b86..7eba854e09ec 100644
> > --- a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
> > +++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
> > @@ -1439,7 +1439,7 @@ static int smu_v13_0_7_get_power_limit(struct smu_context *smu,
> >
> >   static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf)
> >   {
> > -     DpmActivityMonitorCoeffIntExternal_t activity_monitor_external[PP_SMC_POWER_PROFILE_COUNT];
> > +     DpmActivityMonitorCoeffIntExternal_t *activity_monitor_external;
> >       uint32_t i, j, size = 0;
> >       int16_t workload_type = 0;
> >       int result = 0;
> > @@ -1447,6 +1447,12 @@ static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf
> >       if (!buf)
> >               return -EINVAL;
> >
> > +     activity_monitor_external = kcalloc(sizeof(activity_monitor_external),
>
> Hi,
>
> Before, 'activity_monitor_external' was not initialized.
> Maybe kcalloc() is enough?
>
> sizeof(*activity_monitor_external)?
>       ~~~~

I've fixed this up when applying.

Alex

>
> > +                                         PP_SMC_POWER_PROFILE_COUNT,
> > +                                         GFP_KERNEL);
> > +     if (!activity_monitor_external)
> > +             return -ENOMEM;
> > +
> >       size += sysfs_emit_at(buf, size, "                              ");
> >       for (i = 0; i <= PP_SMC_POWER_PROFILE_WINDOW3D; i++)
>
> Unrelated, but wouldn't it be more straightforward with "<
> PP_SMC_POWER_PROFILE_COUNT"?
>
> >               size += sysfs_emit_at(buf, size, "%-14s%s", amdgpu_pp_profile_name[i],
> > @@ -1459,15 +1465,17 @@ static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf
> >               workload_type = smu_cmn_to_asic_specific_index(smu,
> >                                                              CMN2ASIC_MAPPING_WORKLOAD,
> >                                                              i);
> > -             if (workload_type < 0)
> > -                     return -EINVAL;
> > +             if (workload_type < 0) {
> > +                     result = -EINVAL;
> > +                     goto out;
> > +             }
> >
> >               result = smu_cmn_update_table(smu,
> >                                         SMU_TABLE_ACTIVITY_MONITOR_COEFF, workload_type,
> >                                         (void *)(&activity_monitor_external[i]), false);
> >               if (result) {
> >                       dev_err(smu->adev->dev, "[%s] Failed to get activity monitor!", __func__);
> > -                     return result;
> > +                     goto out;
> >               }
> >       }
> >
> > @@ -1495,7 +1503,10 @@ do {                                                                                                   \
> >       PRINT_DPM_MONITOR(Fclk_BoosterFreq);
> >   #undef PRINT_DPM_MONITOR
> >
> > -     return size;
> > +     result = size;
> > +out:
> > +     kfree(activity_monitor_external);
> > +     return result;
> >   }
> >
> >   static int smu_v13_0_7_set_power_profile_mode(struct smu_context *smu, long *input, uint32_t size)
>

diff mbox series

Patch

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
index c270f94a1b86..7eba854e09ec 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
@@ -1439,7 +1439,7 @@  static int smu_v13_0_7_get_power_limit(struct smu_context *smu,
 
 static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf)
 {
-	DpmActivityMonitorCoeffIntExternal_t activity_monitor_external[PP_SMC_POWER_PROFILE_COUNT];
+	DpmActivityMonitorCoeffIntExternal_t *activity_monitor_external;
 	uint32_t i, j, size = 0;
 	int16_t workload_type = 0;
 	int result = 0;
@@ -1447,6 +1447,12 @@  static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf
 	if (!buf)
 		return -EINVAL;
 
+	activity_monitor_external = kcalloc(sizeof(activity_monitor_external),
+					    PP_SMC_POWER_PROFILE_COUNT,
+					    GFP_KERNEL);
+	if (!activity_monitor_external)
+		return -ENOMEM;
+
 	size += sysfs_emit_at(buf, size, "                              ");
 	for (i = 0; i <= PP_SMC_POWER_PROFILE_WINDOW3D; i++)
 		size += sysfs_emit_at(buf, size, "%-14s%s", amdgpu_pp_profile_name[i],
@@ -1459,15 +1465,17 @@  static int smu_v13_0_7_get_power_profile_mode(struct smu_context *smu, char *buf
 		workload_type = smu_cmn_to_asic_specific_index(smu,
 							       CMN2ASIC_MAPPING_WORKLOAD,
 							       i);
-		if (workload_type < 0)
-			return -EINVAL;
+		if (workload_type < 0) {
+			result = -EINVAL;
+			goto out;
+		}
 
 		result = smu_cmn_update_table(smu,
 					  SMU_TABLE_ACTIVITY_MONITOR_COEFF, workload_type,
 					  (void *)(&activity_monitor_external[i]), false);
 		if (result) {
 			dev_err(smu->adev->dev, "[%s] Failed to get activity monitor!", __func__);
-			return result;
+			goto out;
 		}
 	}
 
@@ -1495,7 +1503,10 @@  do {													\
 	PRINT_DPM_MONITOR(Fclk_BoosterFreq);
 #undef PRINT_DPM_MONITOR
 
-	return size;
+	result = size;
+out:
+	kfree(activity_monitor_external);
+	return result;
 }
 
 static int smu_v13_0_7_set_power_profile_mode(struct smu_context *smu, long *input, uint32_t size)