[PATCH] drm/i915: Avoid NULL ctx->obj dereference in debugfs/i915_context_info

[PATCH] drm/i915: Avoid NULL ctx->obj dereference in debugfs/i915_context_info

[Chris Wilson]

In commit 691e6415c891b8b2b082a120b896b443531c4d45
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Wed Apr 9 09:07:36 2014 +0100

    drm/i915: Always use kref tracking for all contexts.

we populated fake contexts on all platforms. These were identical to the
full hardware context tracking structs, except for the ctx->obj used to
store the hardware state. However, there remained one place where we
assumed that if a context existed, it would have an object associated
with it.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77717
Testcase: igt/drv_suspend/debugfs-reader
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 3c066e635022..9f50675c327a 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1796,6 +1796,9 @@ static int i915_context_status(struct seq_file *m, void *unused)
 	}
 
 	list_for_each_entry(ctx, &dev_priv->context_list, link) {
+		if (ctx->obj == NULL)
+			continue;
+
 		seq_puts(m, "HW context ");
 		describe_ctx(m, ctx);
 		for_each_ring(ring, dev_priv, i)
-- 
2.0.0.rc0

Re: [PATCH] drm/i915: Avoid NULL ctx->obj dereference in debugfs/i915_context_info

[Daniel Vetter]

On Wed, Apr 30, 2014 at 08:30:00AM +0100, Chris Wilson wrote:
> In commit 691e6415c891b8b2b082a120b896b443531c4d45
> Author: Chris Wilson <chris@chris-wilson.co.uk>
> Date:   Wed Apr 9 09:07:36 2014 +0100
> 
>     drm/i915: Always use kref tracking for all contexts.
> 
> we populated fake contexts on all platforms. These were identical to the
> full hardware context tracking structs, except for the ctx->obj used to
> store the hardware state. However, there remained one place where we
> assumed that if a context existed, it would have an object associated
> with it.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77717
> Testcase: igt/drv_suspend/debugfs-reader
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Queued for -next, thanks for the patch.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_debugfs.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 3c066e635022..9f50675c327a 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -1796,6 +1796,9 @@ static int i915_context_status(struct seq_file *m, void *unused)
>  	}
>  
>  	list_for_each_entry(ctx, &dev_priv->context_list, link) {
> +		if (ctx->obj == NULL)
> +			continue;
> +
>  		seq_puts(m, "HW context ");
>  		describe_ctx(m, ctx);
>  		for_each_ring(ring, dev_priv, i)
> -- 
> 2.0.0.rc0
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [PATCH] drm/i915: Avoid NULL ctx->obj dereference in debugfs/i915_context_info

[Jani Nikula]

On Wed, 30 Apr 2014, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Wed, Apr 30, 2014 at 08:30:00AM +0100, Chris Wilson wrote:
>> In commit 691e6415c891b8b2b082a120b896b443531c4d45
>> Author: Chris Wilson <chris@chris-wilson.co.uk>
>> Date:   Wed Apr 9 09:07:36 2014 +0100
>> 
>>     drm/i915: Always use kref tracking for all contexts.
>> 
>> we populated fake contexts on all platforms. These were identical to the
>> full hardware context tracking structs, except for the ctx->obj used to
>> store the hardware state. However, there remained one place where we
>> assumed that if a context existed, it would have an object associated
>> with it.
>> 
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77717
>> Testcase: igt/drv_suspend/debugfs-reader
>> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>
> Queued for -next, thanks for the patch.

Why not -fixes? "drm/i915: Always use kref tracking for all contexts" is
present in v3.15-rc2.

Jani.

> -Daniel
>
>> ---
>>  drivers/gpu/drm/i915/i915_debugfs.c | 3 +++
>>  1 file changed, 3 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
>> index 3c066e635022..9f50675c327a 100644
>> --- a/drivers/gpu/drm/i915/i915_debugfs.c
>> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
>> @@ -1796,6 +1796,9 @@ static int i915_context_status(struct seq_file *m, void *unused)
>>  	}
>>  
>>  	list_for_each_entry(ctx, &dev_priv->context_list, link) {
>> +		if (ctx->obj == NULL)
>> +			continue;
>> +
>>  		seq_puts(m, "HW context ");
>>  		describe_ctx(m, ctx);
>>  		for_each_ring(ring, dev_priv, i)
>> -- 
>> 2.0.0.rc0
>> 
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Jani Nikula, Intel Open Source Technology Center

Re: [PATCH] drm/i915: Avoid NULL ctx->obj dereference in debugfs/i915_context_info

[Daniel Vetter]

On Wed, Apr 30, 2014 at 02:00:16PM +0300, Jani Nikula wrote:
> On Wed, 30 Apr 2014, Daniel Vetter <daniel@ffwll.ch> wrote:
> > On Wed, Apr 30, 2014 at 08:30:00AM +0100, Chris Wilson wrote:
> >> In commit 691e6415c891b8b2b082a120b896b443531c4d45
> >> Author: Chris Wilson <chris@chris-wilson.co.uk>
> >> Date:   Wed Apr 9 09:07:36 2014 +0100
> >> 
> >>     drm/i915: Always use kref tracking for all contexts.
> >> 
> >> we populated fake contexts on all platforms. These were identical to the
> >> full hardware context tracking structs, except for the ctx->obj used to
> >> store the hardware state. However, there remained one place where we
> >> assumed that if a context existed, it would have an object associated
> >> with it.
> >> 
> >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77717
> >> Testcase: igt/drv_suspend/debugfs-reader
> >> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> >
> > Queued for -next, thanks for the patch.
> 
> Why not -fixes? "drm/i915: Always use kref tracking for all contexts" is
> present in v3.15-rc2.

I guess we could merge it to -fixes, otoh this is for debugfs ... Dunno
whether we should throw this at grumpy Linus really.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch