[Intel-gfx] [PATCH v2 3/9] drm/i915: Split i9xx_read_lut_8() to gmch vs. ilk variants

[Ville Syrjälä]

On Wed, Mar 04, 2020 at 10:54:44AM +0800, kbuild test robot wrote:
> Hi Ville,
> 
> Thank you for the patch! Perhaps something to improve:
> 
> [auto build test WARNING on drm-intel/for-linux-next]
> [also build test WARNING on drm-tip/drm-tip]
> [cannot apply to v5.6-rc4 next-20200303]
> [if your patch is applied to the wrong git tree, please drop us a note to help
> improve the system. BTW, we also suggest to use '--base' option to specify the
> base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
> 
> url:    https://github.com/0day-ci/linux/commits/Ville-Syrjala/drm-i915-Gamma-cleanups/20200304-043847
> base:   git://anongit.freedesktop.org/drm-intel for-linux-next
> 
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp at intel.com>
> 
> New smatch warnings:
> drivers/gpu/drm/i915/display/intel_color.c:1840 ilk_read_lut_8() error: potential null dereference 'blob'.  (drm_property_create_blob returns null)

drm_property_create_blob() does _not_ return NULL. Why does this thing
think it does?

> 
> Old smatch warnings:
> drivers/gpu/drm/i915/display/intel_color.c:1706 i9xx_read_lut_8() error: potential null dereference 'blob'.  (drm_property_create_blob returns null)
> drivers/gpu/drm/i915/display/intel_color.c:1747 i965_read_lut_10p6() error: potential null dereference 'blob'.  (drm_property_create_blob returns null)
> drivers/gpu/drm/i915/display/intel_color.c:1799 chv_read_cgm_lut() error: potential null dereference 'blob'.  (drm_property_create_blob returns null)
> drivers/gpu/drm/i915/display/intel_color.c:1873 ilk_read_lut_10() error: potential null dereference 'blob'.  (drm_property_create_blob returns null)
> drivers/gpu/drm/i915/display/intel_color.c:1920 glk_read_lut_10() error: potential null dereference 'blob'.  (drm_property_create_blob returns null)
> 
> vim +/blob +1840 drivers/gpu/drm/i915/display/intel_color.c
> 
>   1823	
>   1824	static struct drm_property_blob *
>   1825	ilk_read_lut_8(const struct intel_crtc_state *crtc_state)
>   1826	{
>   1827		struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>   1828		struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>   1829		enum pipe pipe = crtc->pipe;
>   1830		struct drm_property_blob *blob;
>   1831		struct drm_color_lut *blob_data;
>   1832		u32 i, val;
>   1833	
>   1834		blob = drm_property_create_blob(&dev_priv->drm,
>   1835						sizeof(struct drm_color_lut) * LEGACY_LUT_LENGTH,
>   1836						NULL);
>   1837		if (IS_ERR(blob))
>   1838			return NULL;
>   1839	
> > 1840		blob_data = blob->data;
>   1841	
>   1842		for (i = 0; i < LEGACY_LUT_LENGTH; i++) {
>   1843			val = intel_de_read(dev_priv, LGC_PALETTE(pipe, i));
>   1844	
>   1845			blob_data[i].red = intel_color_lut_pack(REG_FIELD_GET(
>   1846								LGC_PALETTE_RED_MASK, val), 8);
>   1847			blob_data[i].green = intel_color_lut_pack(REG_FIELD_GET(
>   1848								  LGC_PALETTE_GREEN_MASK, val), 8);
>   1849			blob_data[i].blue = intel_color_lut_pack(REG_FIELD_GET(
>   1850								 LGC_PALETTE_BLUE_MASK, val), 8);
>   1851		}
>   1852	
>   1853		return blob;
>   1854	}
>   1855	
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

-- 
Ville Syrjälä
Intel