tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: caffb99b6929f41a69edbb5aef3a359bf45f3315 commit: 100882673ab83b55ea0e9ed3ad301125d36039a3 drm/i915: Split i9xx_read_lut_8() to gmch vs. ilk variants date: 3 months ago config: i386-allyesconfig (attached as .config) compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0 reproduce (this is a W=1 build): git checkout 100882673ab83b55ea0e9ed3ad301125d36039a3 # save the attached .config to linux build tree make ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; 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) 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 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