Re: [PATCH v11 5/6] ndctl/papr_scm,uapi: Add support for PAPR nvdimm specific methods

From: Dan Williams
Date: Mon Jun 08 2020 - 20:47:00 EST


On Mon, Jun 8, 2020 at 5:16 PM kernel test robot <lkp@xxxxxxxxx> wrote:
>
> Hi Vaibhav,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on powerpc/next]
> [also build test WARNING on linus/master v5.7 next-20200605]
> [cannot apply to linux-nvdimm/libnvdimm-for-next scottwood/next]
> [if your patch is applied to the wrong git tree, please drop us a note to help
> improve the system. BTW, we also suggest to use '--base' option to specify the
> base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
>
> url: https://github.com/0day-ci/linux/commits/Vaibhav-Jain/powerpc-papr_scm-Add-support-for-reporting-nvdimm-health/20200607-211653
> base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
> config: powerpc-randconfig-r016-20200607 (attached as .config)
> compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project e429cffd4f228f70c1d9df0e5d77c08590dd9766)
> 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
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All warnings (new ones prefixed by >>, old ones prefixed by <<):
>
> In file included from <built-in>:1:
> >> ./usr/include/asm/papr_pdsm.h:69:20: warning: field 'hdr' with variable sized type 'struct nd_cmd_pkg' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
> struct nd_cmd_pkg hdr; /* Package header containing sub-cmd */

Hi Vaibhav,

This looks like it's going to need another round to get this fixed. I
don't think 'struct nd_pdsm_cmd_pkg' should embed a definition of
'struct nd_cmd_pkg'. An instance of 'struct nd_cmd_pkg' carries a
payload that is the 'pdsm' specifics. As the code has it now it's
defined as a superset of 'struct nd_cmd_pkg' and the compiler warning
is pointing out a real 'struct' organization problem.

Given the soak time needed in -next after the code is finalized this
there's no time to do another round of updates and still make the v5.8
merge window.