From: Jani Nikula <jani.nikula@linux.intel.com>
To: Chris Wilson <chris@chris-wilson.co.uk>,
Steve Hampson <steven.t.hampson@intel.com>,
intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH] Fix NULL pointer found by static analysis
Date: Wed, 23 Sep 2020 12:04:58 +0300 [thread overview]
Message-ID: <87eemsrhhh.fsf@intel.com> (raw)
In-Reply-To: <160085149249.27151.12750028761264321987@build.alporthouse.com>
On Wed, 23 Sep 2020, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> Quoting Steve Hampson (2020-09-23 05:40:54)
>> A static analysis tool has reveiled a NULL pointer error in
>> __i915_gem_object_lock. This appears to be correct as many calls
>> pass a NULL into the ww parameter.
>>
>> Signed-off-by: Steve Hampson <steven.t.hampson@intel.com>
>> ---
>> drivers/gpu/drm/i915/gem/i915_gem_object.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
>> index d46db8d8f38e..9b18ead42991 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
>> @@ -126,7 +126,7 @@ static inline int __i915_gem_object_lock(struct drm_i915_gem_object *obj,
>> if (ret == -EALREADY)
>> ret = 0;
>>
>> - if (ret == -EDEADLK)
>> + if (ret == -EDEADLK && ww)
>
> EDEADLK is predicated by ww already.
The hard part is that neither the analyzer nor a human who doesn't know
how dma_resv_lock* work can easily deduce that. :(
BR,
Jani.
--
Jani Nikula, Intel Open Source Graphics Center
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next prev parent reply other threads:[~2020-09-23 9:05 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-23 4:40 [Intel-gfx] [PATCH] Fix NULL pointer found by static analysis Steve Hampson
2020-09-23 5:28 ` [Intel-gfx] ✓ Fi.CI.BAT: success for " Patchwork
2020-09-23 8:48 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork
2020-09-23 8:58 ` [Intel-gfx] [PATCH] " Chris Wilson
2020-09-23 9:04 ` Jani Nikula [this message]
2020-09-23 21:23 ` Hampson, Steven T
2020-09-23 21:57 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for Fix NULL pointer found by static analysis (rev2) Patchwork
2020-09-23 22:22 ` [Intel-gfx] ✓ Fi.CI.BAT: success " Patchwork
2020-09-24 1:08 ` [Intel-gfx] ✗ Fi.CI.IGT: failure " Patchwork
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