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* [PATCH v2] drm/etnaviv: fix perfmon domain interation
@ 2020-05-19  5:30 ` Christian Gmeiner
  0 siblings, 0 replies; 4+ messages in thread
From: Christian Gmeiner @ 2020-05-19  5:30 UTC (permalink / raw)
  To: linux-kernel
  Cc: Christian Gmeiner, Paul Cercueil, stable, Lucas Stach,
	Russell King, David Airlie, Daniel Vetter, etnaviv, dri-devel

The GC860 has one GPU device which has a 2d and 3d core. In this case
we want to expose perfmon information for both cores.

The driver has one array which contains all possible perfmon domains
with some meta data - doms_meta. Here we can see that for the GC860
two elements of that array are relevant:

  doms_3d: is at index 0 in the doms_meta array with 8 perfmon domains
  doms_2d: is at index 1 in the doms_meta array with 1 perfmon domain

The userspace driver wants to get a list of all perfmon domains and
their perfmon signals. This is done by iterating over all domains and
their signals. If the userspace driver wants to access the domain with
id 8 the kernel driver fails and returns invalid data from doms_3d with
and invalid offset.

This results in:
  Unable to handle kernel paging request at virtual address 00000000

On such a device it is not possible to use the userspace driver at all.

The fix for this off-by-one error is quite simple.

Reported-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Paul Cercueil <paul@crapouillou.net>
Fixes: ed1dd899baa3 ("drm/etnaviv: rework perfmon query infrastructure")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>

---
 drivers/gpu/drm/etnaviv/etnaviv_perfmon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
index e6795bafcbb9..75f9db8f7bec 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
@@ -453,7 +453,7 @@ static const struct etnaviv_pm_domain *pm_domain(const struct etnaviv_gpu *gpu,
 		if (!(gpu->identity.features & meta->feature))
 			continue;
 
-		if (meta->nr_domains < (index - offset)) {
+		if (index - offset >= meta->nr_domains) {
 			offset += meta->nr_domains;
 			continue;
 		}
-- 
2.26.2


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH v2] drm/etnaviv: fix perfmon domain interation
@ 2020-05-19  5:30 ` Christian Gmeiner
  0 siblings, 0 replies; 4+ messages in thread
From: Christian Gmeiner @ 2020-05-19  5:30 UTC (permalink / raw)
  To: linux-kernel
  Cc: David Airlie, etnaviv, stable, Paul Cercueil, dri-devel, Russell King

The GC860 has one GPU device which has a 2d and 3d core. In this case
we want to expose perfmon information for both cores.

The driver has one array which contains all possible perfmon domains
with some meta data - doms_meta. Here we can see that for the GC860
two elements of that array are relevant:

  doms_3d: is at index 0 in the doms_meta array with 8 perfmon domains
  doms_2d: is at index 1 in the doms_meta array with 1 perfmon domain

The userspace driver wants to get a list of all perfmon domains and
their perfmon signals. This is done by iterating over all domains and
their signals. If the userspace driver wants to access the domain with
id 8 the kernel driver fails and returns invalid data from doms_3d with
and invalid offset.

This results in:
  Unable to handle kernel paging request at virtual address 00000000

On such a device it is not possible to use the userspace driver at all.

The fix for this off-by-one error is quite simple.

Reported-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Paul Cercueil <paul@crapouillou.net>
Fixes: ed1dd899baa3 ("drm/etnaviv: rework perfmon query infrastructure")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>

---
 drivers/gpu/drm/etnaviv/etnaviv_perfmon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
index e6795bafcbb9..75f9db8f7bec 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
@@ -453,7 +453,7 @@ static const struct etnaviv_pm_domain *pm_domain(const struct etnaviv_gpu *gpu,
 		if (!(gpu->identity.features & meta->feature))
 			continue;
 
-		if (meta->nr_domains < (index - offset)) {
+		if (index - offset >= meta->nr_domains) {
 			offset += meta->nr_domains;
 			continue;
 		}
-- 
2.26.2

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH v2] drm/etnaviv: fix perfmon domain interation
  2020-05-19  5:30 ` Christian Gmeiner
@ 2020-05-19 10:48   ` Lucas Stach
  -1 siblings, 0 replies; 4+ messages in thread
From: Lucas Stach @ 2020-05-19 10:48 UTC (permalink / raw)
  To: Christian Gmeiner, linux-kernel
  Cc: Paul Cercueil, stable, Russell King, David Airlie, Daniel Vetter,
	etnaviv, dri-devel

Am Dienstag, den 19.05.2020, 07:30 +0200 schrieb Christian Gmeiner:
> The GC860 has one GPU device which has a 2d and 3d core. In this case
> we want to expose perfmon information for both cores.
> 
> The driver has one array which contains all possible perfmon domains
> with some meta data - doms_meta. Here we can see that for the GC860
> two elements of that array are relevant:
> 
>   doms_3d: is at index 0 in the doms_meta array with 8 perfmon domains
>   doms_2d: is at index 1 in the doms_meta array with 1 perfmon domain
> 
> The userspace driver wants to get a list of all perfmon domains and
> their perfmon signals. This is done by iterating over all domains and
> their signals. If the userspace driver wants to access the domain with
> id 8 the kernel driver fails and returns invalid data from doms_3d with
> and invalid offset.
> 
> This results in:
>   Unable to handle kernel paging request at virtual address 00000000
> 
> On such a device it is not possible to use the userspace driver at all.
> 
> The fix for this off-by-one error is quite simple.
> 
> Reported-by: Paul Cercueil <paul@crapouillou.net>
> Tested-by: Paul Cercueil <paul@crapouillou.net>
> Fixes: ed1dd899baa3 ("drm/etnaviv: rework perfmon query infrastructure")
> Cc: stable@vger.kernel.org
> Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>

Thanks, applied to etnaviv/fixes.

Regards,
Lucas

> ---
>  drivers/gpu/drm/etnaviv/etnaviv_perfmon.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
> index e6795bafcbb9..75f9db8f7bec 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
> @@ -453,7 +453,7 @@ static const struct etnaviv_pm_domain *pm_domain(const struct etnaviv_gpu *gpu,
>  		if (!(gpu->identity.features & meta->feature))
>  			continue;
>  
> -		if (meta->nr_domains < (index - offset)) {
> +		if (index - offset >= meta->nr_domains) {
>  			offset += meta->nr_domains;
>  			continue;
>  		}


^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH v2] drm/etnaviv: fix perfmon domain interation
@ 2020-05-19 10:48   ` Lucas Stach
  0 siblings, 0 replies; 4+ messages in thread
From: Lucas Stach @ 2020-05-19 10:48 UTC (permalink / raw)
  To: Christian Gmeiner, linux-kernel
  Cc: David Airlie, etnaviv, stable, Paul Cercueil, dri-devel, Russell King

Am Dienstag, den 19.05.2020, 07:30 +0200 schrieb Christian Gmeiner:
> The GC860 has one GPU device which has a 2d and 3d core. In this case
> we want to expose perfmon information for both cores.
> 
> The driver has one array which contains all possible perfmon domains
> with some meta data - doms_meta. Here we can see that for the GC860
> two elements of that array are relevant:
> 
>   doms_3d: is at index 0 in the doms_meta array with 8 perfmon domains
>   doms_2d: is at index 1 in the doms_meta array with 1 perfmon domain
> 
> The userspace driver wants to get a list of all perfmon domains and
> their perfmon signals. This is done by iterating over all domains and
> their signals. If the userspace driver wants to access the domain with
> id 8 the kernel driver fails and returns invalid data from doms_3d with
> and invalid offset.
> 
> This results in:
>   Unable to handle kernel paging request at virtual address 00000000
> 
> On such a device it is not possible to use the userspace driver at all.
> 
> The fix for this off-by-one error is quite simple.
> 
> Reported-by: Paul Cercueil <paul@crapouillou.net>
> Tested-by: Paul Cercueil <paul@crapouillou.net>
> Fixes: ed1dd899baa3 ("drm/etnaviv: rework perfmon query infrastructure")
> Cc: stable@vger.kernel.org
> Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>

Thanks, applied to etnaviv/fixes.

Regards,
Lucas

> ---
>  drivers/gpu/drm/etnaviv/etnaviv_perfmon.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
> index e6795bafcbb9..75f9db8f7bec 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
> @@ -453,7 +453,7 @@ static const struct etnaviv_pm_domain *pm_domain(const struct etnaviv_gpu *gpu,
>  		if (!(gpu->identity.features & meta->feature))
>  			continue;
>  
> -		if (meta->nr_domains < (index - offset)) {
> +		if (index - offset >= meta->nr_domains) {
>  			offset += meta->nr_domains;
>  			continue;
>  		}

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-05-19 10:48 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-05-19  5:30 [PATCH v2] drm/etnaviv: fix perfmon domain interation Christian Gmeiner
2020-05-19  5:30 ` Christian Gmeiner
2020-05-19 10:48 ` Lucas Stach
2020-05-19 10:48   ` Lucas Stach

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