[PATCH] drm/i915/selftests: Fix uninitialized variable

[PATCH] drm/i915/selftests: Fix uninitialized variable

[Gustavo A. R. Silva]

There is a potential execution path in which variable err is
returned without being properly initialized previously.

Fix this by initializing variable err to 0.

Addresses-Coverity-ID: 1468362 ("Uninitialized scalar variable")
Fixes: f4ecfbfc32ed ("drm/i915: Check whitelist registers across resets")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/gpu/drm/i915/selftests/intel_workarounds.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/selftests/intel_workarounds.c b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
index 5455b26..17444a3 100644
--- a/drivers/gpu/drm/i915/selftests/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
@@ -239,7 +239,7 @@ static int live_reset_whitelist(void *arg)
 	struct intel_engine_cs *engine = i915->engine[RCS];
 	struct i915_gpu_error *error = &i915->gpu_error;
 	struct whitelist w;
-	int err;
+	int err = 0;
 
 	/* If we reset the gpu, we should not lose the RING_NONPRIV */
 
-- 
2.7.4

Re: [PATCH] drm/i915/selftests: Fix uninitialized variable

[Chris Wilson]

Quoting Gustavo A. R. Silva (2018-04-24 14:15:45)
> There is a potential execution path in which variable err is
> returned without being properly initialized previously.
> 
> Fix this by initializing variable err to 0.

err is only returned along an error path, returning 0 would not be
useful. Which path? All the error paths look correct to me.
-Chris

Re: [PATCH] drm/i915/selftests: Fix uninitialized variable

[Chris Wilson]

Quoting Gustavo A. R. Silva (2018-04-24 14:15:45)
> There is a potential execution path in which variable err is
> returned without being properly initialized previously.
> 
> Fix this by initializing variable err to 0.

err is only returned along an error path, returning 0 would not be
useful. Which path? All the error paths look correct to me.
-Chris

Re: [PATCH] drm/i915/selftests: Fix uninitialized variable

[Gustavo A. R. Silva]

On 04/24/2018 08:22 AM, Chris Wilson wrote:
> Quoting Gustavo A. R. Silva (2018-04-24 14:15:45)
>> There is a potential execution path in which variable err is
>> returned without being properly initialized previously.
>>
>> Fix this by initializing variable err to 0.
> 
> err is only returned along an error path, returning 0 would not be
> useful. Which path? All the error paths look correct to me.
> -Chris
> 

If the following two conditions take the false branch then the function 
returns err with a random stack value:

if (intel_has_reset_engine(i915)) {
		...
}

if (intel_has_gpu_reset(i915)) {
		...
}

Thanks
--
Gustavo

Re: [PATCH] drm/i915/selftests: Fix uninitialized variable

[Chris Wilson]

Quoting Gustavo A. R. Silva (2018-04-24 14:30:58)
> 
> 
> On 04/24/2018 08:22 AM, Chris Wilson wrote:
> > Quoting Gustavo A. R. Silva (2018-04-24 14:15:45)
> >> There is a potential execution path in which variable err is
> >> returned without being properly initialized previously.
> >>
> >> Fix this by initializing variable err to 0.
> > 
> > err is only returned along an error path, returning 0 would not be
> > useful. Which path? All the error paths look correct to me.
> > -Chris
> > 
> 
> If the following two conditions take the false branch then the function 
> returns err with a random stack value:


It would help if I read the right function. Ok,
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
-Chris

Re: [PATCH] drm/i915/selftests: Fix uninitialized variable

[Chris Wilson]

Quoting Gustavo A. R. Silva (2018-04-24 14:30:58)
> 
> 
> On 04/24/2018 08:22 AM, Chris Wilson wrote:
> > Quoting Gustavo A. R. Silva (2018-04-24 14:15:45)
> >> There is a potential execution path in which variable err is
> >> returned without being properly initialized previously.
> >>
> >> Fix this by initializing variable err to 0.
> > 
> > err is only returned along an error path, returning 0 would not be
> > useful. Which path? All the error paths look correct to me.
> > -Chris
> > 
> 
> If the following two conditions take the false branch then the function 
> returns err with a random stack value:


It would help if I read the right function. Ok,
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
-Chris
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✓ Fi.CI.BAT: success for drm/i915/selftests: Fix uninitialized variable

[Patchwork]

== Series Details ==

Series: drm/i915/selftests: Fix uninitialized variable
URL   : https://patchwork.freedesktop.org/series/42194/
State : success

== Summary ==

= CI Bug Log - changes from CI_DRM_4087 -> Patchwork_8790 =

== Summary - SUCCESS ==

  No regressions found.

  External URL: https://patchwork.freedesktop.org/api/1.0/series/42194/revisions/1/mbox/


== Changes ==

  No changes found


== Participating hosts (37 -> 34) ==

  Missing    (3): fi-ctg-p8600 fi-ilk-m540 fi-skl-6700hq 


== Build changes ==

    * Linux: CI_DRM_4087 -> Patchwork_8790

  CI_DRM_4087: d04fd4f6d93cea918521059db8358ff9e7a4a03b @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_4446: e5e8dafc991ee922ec159491c680caff0cfe9235 @ git://anongit.freedesktop.org/xorg/app/intel-gpu-tools
  Patchwork_8790: 0fd599472ba7fbbc7f01f655f08a1a17965fd1a7 @ git://anongit.freedesktop.org/gfx-ci/linux
  piglit_4446: a2f486679f467cd6e82578384f56d4aabaa8cf2e @ git://anongit.freedesktop.org/piglit


== Linux commits ==

0fd599472ba7 drm/i915/selftests: Fix uninitialized variable

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_8790/issues.html
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✗ Fi.CI.IGT: failure for drm/i915/selftests: Fix uninitialized variable

[Patchwork]

== Series Details ==

Series: drm/i915/selftests: Fix uninitialized variable
URL   : https://patchwork.freedesktop.org/series/42194/
State : failure

== Summary ==

= CI Bug Log - changes from CI_DRM_4087_full -> Patchwork_8790_full =

== Summary - FAILURE ==

  Serious unknown changes coming with Patchwork_8790_full absolutely need to be
  verified manually.
  
  If you think the reported changes have nothing to do with the changes
  introduced in Patchwork_8790_full, please notify your bug team to allow them
  to document this new failure mode, which will reduce false positives in CI.

  External URL: https://patchwork.freedesktop.org/api/1.0/series/42194/revisions/1/mbox/

== Possible new issues ==

  Here are the unknown changes that may have been introduced in Patchwork_8790_full:

  === IGT changes ===

    ==== Possible regressions ====

    igt@prime_busy@wait-before-blt:
      shard-glk:          PASS -> FAIL

    
    ==== Warnings ====

    igt@gem_exec_schedule@deep-bsd1:
      shard-kbl:          SKIP -> PASS +2

    igt@kms_atomic_interruptible@legacy-cursor:
      shard-snb:          PASS -> SKIP +2

    
== Known issues ==

  Here are the changes found in Patchwork_8790_full that come from known issues:

  === IGT changes ===

    ==== Issues hit ====

    igt@kms_flip@blocking-absolute-wf_vblank-interruptible:
      shard-glk:          PASS -> FAIL (fdo#106134)

    igt@kms_flip@plain-flip-ts-check:
      shard-hsw:          PASS -> FAIL (fdo#100368)

    igt@kms_sysfs_edid_timing:
      shard-apl:          PASS -> WARN (fdo#100047)

    
    ==== Possible fixes ====

    igt@gem_eio@in-flight-contexts-immediate:
      shard-glk:          FAIL -> PASS

    igt@gem_eio@in-flight-immediate:
      shard-glk:          FAIL (fdo#105957) -> PASS

    igt@kms_flip@dpms-vs-vblank-race-interruptible:
      shard-glk:          FAIL (fdo#103060) -> PASS

    igt@kms_flip@plain-flip-fb-recreate-interruptible:
      shard-glk:          FAIL (fdo#100368) -> PASS +2

    igt@kms_flip@plain-flip-ts-check-interruptible:
      shard-hsw:          FAIL (fdo#100368) -> PASS

    igt@kms_setmode@basic:
      shard-hsw:          FAIL (fdo#99912) -> PASS

    
  fdo#100047 https://bugs.freedesktop.org/show_bug.cgi?id=100047
  fdo#100368 https://bugs.freedesktop.org/show_bug.cgi?id=100368
  fdo#103060 https://bugs.freedesktop.org/show_bug.cgi?id=103060
  fdo#105957 https://bugs.freedesktop.org/show_bug.cgi?id=105957
  fdo#106134 https://bugs.freedesktop.org/show_bug.cgi?id=106134
  fdo#99912 https://bugs.freedesktop.org/show_bug.cgi?id=99912


== Participating hosts (6 -> 5) ==

  Missing    (1): shard-glkb 


== Build changes ==

    * Linux: CI_DRM_4087 -> Patchwork_8790

  CI_DRM_4087: d04fd4f6d93cea918521059db8358ff9e7a4a03b @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_4446: e5e8dafc991ee922ec159491c680caff0cfe9235 @ git://anongit.freedesktop.org/xorg/app/intel-gpu-tools
  Patchwork_8790: 0fd599472ba7fbbc7f01f655f08a1a17965fd1a7 @ git://anongit.freedesktop.org/gfx-ci/linux
  piglit_4446: a2f486679f467cd6e82578384f56d4aabaa8cf2e @ git://anongit.freedesktop.org/piglit

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_8790/shards.html
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Re: ✗ Fi.CI.IGT: failure for drm/i915/selftests: Fix uninitialized variable

[Chris Wilson]

Quoting Patchwork (2018-04-24 20:02:06)
> == Series Details ==
> 
> Series: drm/i915/selftests: Fix uninitialized variable
> URL   : https://patchwork.freedesktop.org/series/42194/
> State : failure
> 
> == Summary ==
> 
> = CI Bug Log - changes from CI_DRM_4087_full -> Patchwork_8790_full =
> 
> == Summary - FAILURE ==
> 
>   Serious unknown changes coming with Patchwork_8790_full absolutely need to be
>   verified manually.
>   
>   If you think the reported changes have nothing to do with the changes
>   introduced in Patchwork_8790_full, please notify your bug team to allow them
>   to document this new failure mode, which will reduce false positives in CI.
> 
>   External URL: https://patchwork.freedesktop.org/api/1.0/series/42194/revisions/1/mbox/
> 
> == Possible new issues ==
> 
>   Here are the unknown changes that may have been introduced in Patchwork_8790_full:
> 
>   === IGT changes ===
> 
>     ==== Possible regressions ====
> 
>     igt@prime_busy@wait-before-blt:
>       shard-glk:          PASS -> FAIL

Not related (obviously!)

Thanks for the fixup, applied.
-Chris
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Re: ✗ Fi.CI.IGT: failure for drm/i915/selftests: Fix uninitialized variable

[Gustavo A. R. Silva]

On 04/24/2018 02:42 PM, Chris Wilson wrote:
> Quoting Patchwork (2018-04-24 20:02:06)
>> == Series Details ==
>>
>> Series: drm/i915/selftests: Fix uninitialized variable
>> URL   : https://patchwork.freedesktop.org/series/42194/
>> State : failure
>>
>> == Summary ==
>>
>> = CI Bug Log - changes from CI_DRM_4087_full -> Patchwork_8790_full =
>>
>> == Summary - FAILURE ==
>>
>>    Serious unknown changes coming with Patchwork_8790_full absolutely need to be
>>    verified manually.
>>    
>>    If you think the reported changes have nothing to do with the changes
>>    introduced in Patchwork_8790_full, please notify your bug team to allow them
>>    to document this new failure mode, which will reduce false positives in CI.
>>
>>    External URL: https://patchwork.freedesktop.org/api/1.0/series/42194/revisions/1/mbox/
>>
>> == Possible new issues ==
>>
>>    Here are the unknown changes that may have been introduced in Patchwork_8790_full:
>>
>>    === IGT changes ===
>>
>>      ==== Possible regressions ====
>>
>>      igt@prime_busy@wait-before-blt:
>>        shard-glk:          PASS -> FAIL
> 
> Not related (obviously!)
> 
> Thanks for the fixup, applied.
> -Chris
> 

Yep. I noticed that.

Glad to help. :)

Thanks
--
Gustavo
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