Re: [PATCH v4 2/3] riscv: optimized memmove

[Emil Renner Berthing <kernel@esmil.dk>]

On Mon, 27 Sept 2021 at 12:49, Matteo Croce <mcroce@linux.microsoft.com> wrote:
>
> On Mon, Sep 20, 2021 at 12:06 AM kernel test robot <lkp@intel.com> wrote:
> >
> > Hi Matteo,
> >
> > Thank you for the patch! Yet something to improve:
> >
> > [auto build test ERROR on linux/master]
> > [also build test ERROR on linus/master v5.15-rc1 next-20210917]
> > [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/Matteo-Croce/riscv-optimized-mem-functions/20210920-032303
> > base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git bdb575f872175ed0ecf2638369da1cb7a6e86a14
> > config: riscv-randconfig-r004-20210919 (attached as .config)
> > compiler: riscv64-linux-gcc (GCC) 11.2.0
> > 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
> >         # https://github.com/0day-ci/linux/commit/9a948fd7d78a58890608e9dd0f77e5ff84f36e3e
> >         git remote add linux-review https://github.com/0day-ci/linux
> >         git fetch --no-tags linux-review Matteo-Croce/riscv-optimized-mem-functions/20210920-032303
> >         git checkout 9a948fd7d78a58890608e9dd0f77e5ff84f36e3e
> >         # save the attached .config to linux build tree
> >         mkdir build_dir
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=riscv SHELL=/bin/bash
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> >
> > All errors (new ones prefixed by >>):
> >
> >    arch/riscv/lib/string.c: In function '__memmove':
> > >> arch/riscv/lib/string.c:89:7: error: inlining failed in call to 'always_inline' 'memcpy': function body can be overwritten at link time
> >       89 | void *memcpy(void *dest, const void *src, size_t count) __weak __alias(__memcpy);
> >          |       ^~~~~~
> >    arch/riscv/lib/string.c:99:24: note: called from here
> >       99 |                 return memcpy(dest, src, count);
> >          |                        ^~~~~~~~~~~~~~~~~~~~~~~~
> >
> >
> > vim +89 arch/riscv/lib/string.c
> >
> > 86c5866e9b7fdd Matteo Croce 2021-09-19  88
> > 86c5866e9b7fdd Matteo Croce 2021-09-19 @89  void *memcpy(void *dest, const void *src, size_t count) __weak __alias(__memcpy);
> > 86c5866e9b7fdd Matteo Croce 2021-09-19  90  EXPORT_SYMBOL(memcpy);
> > 9a948fd7d78a58 Matteo Croce 2021-09-19  91
> >
> > ---
> > 0-DAY CI Kernel Test Service, Intel Corporation
> > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
>
> How can we fix this? Maybe calling __memcpy() instead?

Yes, that fixes building with CONFIG_FORTIFY_SOURCE=y for me. Kasan
already wraps memmove itself, so it should be fine to call __memcpy
directly.

/Emil