Re: [PATCH bpf-next 5/5] bpf: Implement bpf_get_attach_cookie() for tracing programs.

[kernel test robot <lkp@intel.com>]

Hi Kui-Feng,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on bpf-next/master]

url:    https://github.com/0day-ci/linux/commits/Kui-Feng-Lee/Attach-a-cookie-to-a-tracing-program/20220127-054929
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: mips-allmodconfig (https://download.01.org/0day-ci/archive/20220127/202201270704.kcMiWFUK-lkp@intel.com/config)
compiler: mips-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/6dffffc1fe68f386715b4ee396fb6a5c738fb065
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Kui-Feng-Lee/Attach-a-cookie-to-a-tracing-program/20220127-054929
        git checkout 6dffffc1fe68f386715b4ee396fb6a5c738fb065
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=mips SHELL=/bin/bash kernel/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   kernel/trace/bpf_trace.c: In function '____bpf_get_attach_cookie_tracing':
>> kernel/trace/bpf_trace.c:1095:16: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    1095 |         prog = (const struct bpf_prog *)((u64 *)ctx)[-off];
         |                ^


vim +1095 kernel/trace/bpf_trace.c

  1086	
  1087	BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
  1088	{
  1089		const struct bpf_prog *prog;
  1090		int off = get_trampo_var_off(ctx, BPF_TRAMP_F_PROG_ID);
  1091	
  1092		if (off < 0)
  1093			return 0;
  1094	
> 1095		prog = (const struct bpf_prog *)((u64 *)ctx)[-off];
  1096	
  1097		return prog->aux->cookie;
  1098	}
  1099	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org