Re: [PATCH] smp: fix smp_call_function_single_async prototype

[Jian Cai]

Thanks for the patch! Some of the stable kernels also have this
warning, but they don't seem to have the dependencies (4.14, 4,19,
5.4). Do we plan to fix those branches as well?


On Thu, Apr 29, 2021 at 2:46 PM kernel test robot <lkp@xxxxxxxxx> wrote:
>
> Hi Arnd,
>
> I love your patch! Perhaps something to improve:
>
> [auto build test WARNING on next-20210429]
> [cannot apply to linux/master soc/for-next linus/master v5.12 v5.12-rc8 v5.12-rc7 v5.12]
> [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]
>
> url:    https://github.com/0day-ci/linux/commits/Arnd-Bergmann/smp-fix-smp_call_function_single_async-prototype/20210429-231235
> base:    9e5cff2a1315fec1da1f497714395670366506b6
> config: arm64-randconfig-r022-20210429 (attached as .config)
> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 9131a078901b00e68248a27a4f8c4b11bb1db1ae)
> 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 arm64 cross compiling tool for clang build
>         # apt-get install binutils-aarch64-linux-gnu
>         # https://github.com/0day-ci/linux/commit/be40015a8e0990182fa440f75adecf40cf5d0062
>         git remote add linux-review https://github.com/0day-ci/linux
>         git fetch --no-tags linux-review Arnd-Bergmann/smp-fix-smp_call_function_single_async-prototype/20210429-231235
>         git checkout be40015a8e0990182fa440f75adecf40cf5d0062
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm64
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All warnings (new ones prefixed by >>):
>
> >> kernel/smp.c:407:19: warning: passing 8-byte aligned argument to 32-byte aligned parameter 1 of '__csd_lock_wait' may result in an unaligned pointer access [-Walign-mismatch]
>                    __csd_lock_wait(csd);
>                                    ^
>    kernel/smp.c:515:19: warning: passing 8-byte aligned argument to 32-byte aligned parameter 1 of 'csd_lock_record' may result in an unaligned pointer access [-Walign-mismatch]
>                    csd_lock_record(csd);
>                                    ^
>    kernel/smp.c:516:14: warning: passing 8-byte aligned argument to 32-byte aligned parameter 1 of 'csd_unlock' may result in an unaligned pointer access [-Walign-mismatch]
>                    csd_unlock(csd);
>                               ^
>    kernel/smp.c:525:14: warning: passing 8-byte aligned argument to 32-byte aligned parameter 1 of 'csd_unlock' may result in an unaligned pointer access [-Walign-mismatch]
>                    csd_unlock(csd);
>                               ^
>    kernel/smp.c:684:6: warning: no previous prototype for function 'flush_smp_call_function_from_idle' [-Wmissing-prototypes]
>    void flush_smp_call_function_from_idle(void)
>         ^
>    kernel/smp.c:684:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
>    void flush_smp_call_function_from_idle(void)
>    ^
>    static
>    5 warnings generated.
>
>
> vim +/__csd_lock_wait +407 kernel/smp.c
>
> 35feb60474bf4f Paul E. McKenney 2020-06-30  403
> be40015a8e0990 Arnd Bergmann    2021-04-29  404  static __always_inline void csd_lock_wait(struct __call_single_data *csd)
> 8d0968cc6b8ffd Juergen Gross    2021-03-01  405  {
> 8d0968cc6b8ffd Juergen Gross    2021-03-01  406         if (static_branch_unlikely(&csdlock_debug_enabled)) {
> 8d0968cc6b8ffd Juergen Gross    2021-03-01 @407                 __csd_lock_wait(csd);
> 8d0968cc6b8ffd Juergen Gross    2021-03-01  408                 return;
> 8d0968cc6b8ffd Juergen Gross    2021-03-01  409         }
> 8d0968cc6b8ffd Juergen Gross    2021-03-01  410
> 8d0968cc6b8ffd Juergen Gross    2021-03-01  411         smp_cond_load_acquire(&csd->node.u_flags, !(VAL & CSD_FLAG_LOCK));
> 8d0968cc6b8ffd Juergen Gross    2021-03-01  412  }
> a5aabace5fb8ab Juergen Gross    2021-03-01  413
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx