Re: [RFC bpf-next 2/5] bpf: Provide bpf_copy_from_user() and bpf_copy_to_user().

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

Hi,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

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

url:    https://github.com/intel-lab-lkp/linux/commits/kuifeng-meta-com/bpf-enable-sleepable-BPF-programs-attached-to-cgroup-get-set-sockopt/20230722-132551
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/20230722052248.1062582-3-kuifeng%40meta.com
patch subject: [RFC bpf-next 2/5] bpf: Provide bpf_copy_from_user() and bpf_copy_to_user().
config: powerpc-randconfig-r015-20230720 (https://download.01.org/0day-ci/archive/20230722/202307221559.mSQLTotj-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce: (https://download.01.org/0day-ci/archive/20230722/202307221559.mSQLTotj-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202307221559.mSQLTotj-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/bpf/helpers.c:681:17: warning: no previous prototype for function 'bpf_copy_to_user' [-Wmissing-prototypes]
     681 | __bpf_kfunc int bpf_copy_to_user(void *dst__uninit, u32 dst__sz,
         |                 ^
   kernel/bpf/helpers.c:681:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
     681 | __bpf_kfunc int bpf_copy_to_user(void *dst__uninit, u32 dst__sz,
         |             ^
         |             static 
   1 warning generated.
--
>> kernel/bpf/helpers.c:673: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
    * long bpf_copy_to_user(void *dst, u32 size, const void *kern_ptr)


vim +/bpf_copy_to_user +681 kernel/bpf/helpers.c

   671	
   672	/**
 > 673	 * long bpf_copy_to_user(void *dst, u32 size, const void *kern_ptr)
   674	 *     Description
   675	 *             Read *size* bytes from kernel space address *kern_ptr* and
   676	 *              store the data in user space address *dst*. This is a
   677	 *              wrapper of **copy_to_user**\ ().
   678	 *     Return
   679	 *             0 on success, or a negative error in case of failure.
   680	 */
 > 681	__bpf_kfunc int bpf_copy_to_user(void *dst__uninit, u32 dst__sz,
   682					 const void *src__ign)
   683	{
   684		int ret = copy_to_user(dst__uninit, src__ign, dst__sz);
   685	
   686		if (unlikely(ret))
   687			return -EFAULT;
   688	
   689		return ret;
   690	}
   691	

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