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

[Jani Nikula]

On Wed, 30 Apr 2014, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Wed, Apr 30, 2014 at 08:30:00AM +0100, Chris Wilson wrote:
>> In commit 691e6415c891b8b2b082a120b896b443531c4d45
>> Author: Chris Wilson <chris at 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 at 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
>> 
>> _______________________________________________
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>> Intel-gfx at 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 at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Jani Nikula, Intel Open Source Technology Center