Re: [PATCH 1/3] drm/connector: hdmi: Fix memory leak in drm_display_mode_from_cea_vic()

[kernel test robot <lkp@intel.com>]

Hi Jinjie,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on linus/master v6.12-rc3 next-20241017]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Jinjie-Ruan/drm-connector-hdmi-Fix-memory-leak-in-drm_display_mode_from_cea_vic/20241014-152022
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20241014071632.989108-2-ruanjinjie%40huawei.com
patch subject: [PATCH 1/3] drm/connector: hdmi: Fix memory leak in drm_display_mode_from_cea_vic()
config: arc-randconfig-002-20241017 (https://download.01.org/0day-ci/archive/20241018/202410180830.oitxTsOv-lkp@intel.com/config)
compiler: arc-elf-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241018/202410180830.oitxTsOv-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410180830.oitxTsOv-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_drm_hdmi_compute_mode_clock_rgb':
>> drivers/gpu/drm/tests/drm_connector_test.c:1008:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1008 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   In file included from drivers/gpu/drm/tests/drm_connector_test.c:13:
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_drm_hdmi_compute_mode_clock_rgb_10bpc':
   drivers/gpu/drm/tests/drm_connector_test.c:1031:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1031 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_drm_hdmi_compute_mode_clock_rgb_10bpc_vic_1':
   drivers/gpu/drm/tests/drm_connector_test.c:1051:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1051 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_drm_hdmi_compute_mode_clock_rgb_12bpc':
   drivers/gpu/drm/tests/drm_connector_test.c:1074:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1074 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_drm_hdmi_compute_mode_clock_rgb_12bpc_vic_1':
   drivers/gpu/drm/tests/drm_connector_test.c:1094:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1094 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_drm_hdmi_compute_mode_clock_rgb_double':
   drivers/gpu/drm/tests/drm_connector_test.c:1117:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1117 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_connector_hdmi_compute_mode_clock_yuv420_valid':
   drivers/gpu/drm/tests/drm_connector_test.c:1142:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1142 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_connector_hdmi_compute_mode_clock_yuv420_10_bpc':
   drivers/gpu/drm/tests/drm_connector_test.c:1182:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1182 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_connector_hdmi_compute_mode_clock_yuv420_12_bpc':
   drivers/gpu/drm/tests/drm_connector_test.c:1209:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1209 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_connector_hdmi_compute_mode_clock_yuv422_8_bpc':
   drivers/gpu/drm/tests/drm_connector_test.c:1233:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1233 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_connector_hdmi_compute_mode_clock_yuv422_10_bpc':
   drivers/gpu/drm/tests/drm_connector_test.c:1257:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1257 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
   drivers/gpu/drm/tests/drm_connector_test.c: In function 'drm_test_connector_hdmi_compute_mode_clock_yuv422_12_bpc':
   drivers/gpu/drm/tests/drm_connector_test.c:1281:31: warning: passing argument 2 of 'drm_mode_destroy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1281 |         drm_mode_destroy(drm, mode);
         |                               ^~~~
   include/drm/drm_modes.h:456:72: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
     456 | void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode);
         |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for GET_FREE_REGION
   Depends on [n]: SPARSEMEM [=n]
   Selected by [y]:
   - RESOURCE_KUNIT_TEST [=y] && RUNTIME_TESTING_MENU [=y] && KUNIT [=y]


vim +1008 drivers/gpu/drm/tests/drm_connector_test.c

   987	
   988	/*
   989	 * Test that for a given mode, with 8bpc and an RGB output the TMDS
   990	 * character rate is equal to the mode pixel clock.
   991	 */
   992	static void drm_test_drm_hdmi_compute_mode_clock_rgb(struct kunit *test)
   993	{
   994		struct drm_connector_init_priv *priv = test->priv;
   995		const struct drm_display_mode *mode;
   996		unsigned long long rate;
   997		struct drm_device *drm = &priv->drm;
   998	
   999		mode = drm_display_mode_from_cea_vic(drm, 16);
  1000		KUNIT_ASSERT_NOT_NULL(test, mode);
  1001	
  1002		KUNIT_ASSERT_FALSE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
  1003	
  1004		rate = drm_hdmi_compute_mode_clock(mode, 8, HDMI_COLORSPACE_RGB);
  1005		KUNIT_ASSERT_GT(test, rate, 0);
  1006		KUNIT_EXPECT_EQ(test, mode->clock * 1000ULL, rate);
  1007	
> 1008		drm_mode_destroy(drm, mode);
  1009	}
  1010	

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