Re: [PATCH v4 2/4] clk: mediatek: Provide mtk_devm_alloc_clk_data - Markus Schneider-Pargmann

From: Markus Schneider-Pargmann <msp@baylibre.com>
To: kernel test robot <lkp@intel.com>
Cc: Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Fabien Parent <parent.f@gmail.com>,
	AngeloGioacchino Del Regno 
	<angelogioacchino.delregno@collabora.com>,
	kbuild-all@lists.01.org, linux-clk@vger.kernel.org,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 2/4] clk: mediatek: Provide mtk_devm_alloc_clk_data
Date: Mon, 29 Aug 2022 11:33:50 +0200	[thread overview]
Message-ID: <20220829093350.hu734rofg7luwvkp@blmsp> (raw)
In-Reply-To: <202208230714.8DNW6JjZ-lkp@intel.com>

Hi,

On Tue, Aug 23, 2022 at 07:44:26AM +0800, kernel test robot wrote:
> Hi Markus,
> 
> Thank you for the patch! Perhaps something to improve:
> 
> [auto build test WARNING on clk/clk-next]
> [also build test WARNING on robh/for-next linus/master v6.0-rc2 next-20220822]
> [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/Markus-Schneider-Pargmann/clk-mediatek-Add-mt8365-support/20220822-233030
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git clk-next
> config: loongarch-randconfig-c004-20220821 (https://download.01.org/0day-ci/archive/20220823/202208230714.8DNW6JjZ-lkp@intel.com/config)
> compiler: loongarch64-linux-gcc (GCC) 12.1.0
> 
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@intel.com>
> 
> cocci warnings: (new ones prefixed by >>)
> >> drivers/clk/mediatek/clk-mtk.c:64:1-6: WARNING: invalid free of devm_ allocated data
> 
> vim +64 drivers/clk/mediatek/clk-mtk.c
> 
> 9741b1a68035b54 James Liao    2015-04-23  61  
> 609cc5e1a82394e Chen-Yu Tsai  2022-05-19  62  void mtk_free_clk_data(struct clk_hw_onecell_data *clk_data)
> 300796cad22153f Chun-Jie Chen 2021-09-14  63  {
> 300796cad22153f Chun-Jie Chen 2021-09-14 @64  	kfree(clk_data);
> 300796cad22153f Chun-Jie Chen 2021-09-14  65  }
> 609cc5e1a82394e Chen-Yu Tsai  2022-05-19  66  EXPORT_SYMBOL_GPL(mtk_free_clk_data);

I don't see how this should be called with clk_data being initialized by
devm_*. Maybe I am bit code blind.

Do you have an actual call stack how this is supposed to happen? Also I
wasn't able to get the same warning with coccinelle (different
compiler).

Best,
Markus