Re: drivers/platform/chrome/cros_ec_proto_test.c:2530:13: warning: stack frame size (1040) exceeds limit (1024) in 'cros_ec_proto_test_get_sensor_count_legacy'

[Tzung-Bi Shih]

On Sat, Jan 14, 2023 at 10:28:29AM +0800, kernel test robot wrote:
> Hi Tzung-Bi,
> 
> FYI, the error/warning still remains.
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   97ec4d559d939743e8af83628be5af8da610d9dc
> commit: 33f0fdba6066b504ee0b5f1480b1f93b06050df6 platform/chrome: cros_ec_proto: add Kunit tests for get_sensor_count
> date:   6 months ago
> config: powerpc-allmodconfig
> compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 8d9828ef5aa9688500657d36cd2aefbe12bbd162)
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # install powerpc cross compiling tool for clang build
>         # apt-get install binutils-powerpc-linux-gnu
>         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=33f0fdba6066b504ee0b5f1480b1f93b06050df6
>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>         git fetch --no-tags linus master
>         git checkout 33f0fdba6066b504ee0b5f1480b1f93b06050df6
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=powerpc olddefconfig
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash drivers/platform/chrome/ drivers/staging/media/
> 
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> 
> All warnings (new ones prefixed by >>):
> 
> >> drivers/platform/chrome/cros_ec_proto_test.c:2530:13: warning: stack frame size (1040) exceeds limit (1024) in 'cros_ec_proto_test_get_sensor_count_legacy' [-Wframe-larger-than]
>    static void cros_ec_proto_test_get_sensor_count_legacy(struct kunit *test)
>                ^
>    140/1040 (13.46%) spills, 900/1040 (86.54%) variables
>    1 warning generated.

This is the 3rd time to see the warning.  I wasn't able to reproduce the
warning in my environment until I figured out a way by leveraging docker.

Anyway, the proposed fix is at [1].

[1]: https://patchwork.kernel.org/project/chrome-platform/patch/20230117080254.2725536-1-tzungbi@xxxxxxxxxx/.