Re: [RFC PATCH 1/2] binfmt_misc, fork, proc: Introduce flag to expose the interpreted binary in procfs

From: kernel test robot <lkp@intel.com>
To: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: oe-kbuild-all@lists.linux.dev
Subject: Re: [RFC PATCH 1/2] binfmt_misc, fork, proc: Introduce flag to expose the interpreted binary in procfs
Date: Tue, 10 Oct 2023 12:31:32 +0800	[thread overview]
Message-ID: <202310101213.5jXkSFZh-lkp@intel.com> (raw)
In-Reply-To: <20230907204256.3700336-2-gpiccoli@igalia.com>

Hi Guilherme,

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

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on pcmoore-audit/next linus/master v6.6-rc5]
[cannot apply to kees/for-next/execve next-20231009]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Guilherme-G-Piccoli/binfmt_misc-fork-proc-Introduce-flag-to-expose-the-interpreted-binary-in-procfs/20230908-044529
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20230907204256.3700336-2-gpiccoli%40igalia.com
patch subject: [RFC PATCH 1/2] binfmt_misc, fork, proc: Introduce flag to expose the interpreted binary in procfs
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20231010/202310101213.5jXkSFZh-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231010/202310101213.5jXkSFZh-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/202310101213.5jXkSFZh-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/fork.c:641: warning: Function parameter or member 'mm' not described in '__get_mm_exe_or_interp_file'
>> kernel/fork.c:641: warning: Function parameter or member 'prefer_interp' not described in '__get_mm_exe_or_interp_file'
   kernel/fork.c:1445: warning: Function parameter or member 'mm' not described in 'set_mm_exe_file'
   kernel/fork.c:1445: warning: Function parameter or member 'new_exe_file' not described in 'set_mm_exe_file'
>> kernel/fork.c:1445: warning: Function parameter or member 'new_interpreted_file' not described in 'set_mm_exe_file'
   kernel/fork.c:1498: warning: Function parameter or member 'mm' not described in 'replace_mm_exe_file'
   kernel/fork.c:1498: warning: Function parameter or member 'new_exe_file' not described in 'replace_mm_exe_file'
   kernel/fork.c:1551: warning: Function parameter or member 'task' not described in 'get_task_exe_file'
>> kernel/fork.c:1551: warning: Function parameter or member 'prefer_interpreted' not described in 'get_task_exe_file'
   kernel/fork.c:1581: warning: Function parameter or member 'task' not described in 'get_task_mm'
   kernel/fork.c:2156: warning: bad line: 
   kernel/fork.c:2177: warning: Function parameter or member 'ret' not described in '__pidfd_prepare'
   kernel/fork.c:2177: warning: Excess function parameter 'pidfd' description in '__pidfd_prepare'
   kernel/fork.c:2226: warning: Function parameter or member 'ret' not described in 'pidfd_prepare'
   kernel/fork.c:2226: warning: Excess function parameter 'pidfd' description in 'pidfd_prepare'
   kernel/fork.c:3235: warning: expecting prototype for clone3(). Prototype was for sys_clone3() instead

vim +641 kernel/fork.c

^1da177e4c3f41 Linus Torvalds       2005-04-16  630  
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  631  /**
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  632   * __get_mm_exe_or_interp_file - helper that acquires a reference to the mm's
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  633   * executable file, or if prefer_interp is set, go with mm->interpreted_file
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  634   * instead.
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  635   *
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  636   * Returns %NULL if mm has no associated executable/interpreted file.
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  637   * User must release file via fput().
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  638   */
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  639  static inline struct file *__get_mm_exe_or_interp_file(struct mm_struct *mm,
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  640  						       bool prefer_interp)
fe69d560b5bd9e David Hildenbrand    2021-04-23 @641  {
fe69d560b5bd9e David Hildenbrand    2021-04-23  642  	struct file *exe_file;
fe69d560b5bd9e David Hildenbrand    2021-04-23  643  
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  644  	rcu_read_lock();
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  645  
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  646  	if (unlikely(prefer_interp))
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  647  		exe_file = rcu_dereference(mm->interpreted_file);
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  648  	else
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  649  		exe_file = rcu_dereference(mm->exe_file);
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  650  
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  651  	if (exe_file && !get_file_rcu(exe_file))
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  652  		exe_file = NULL;
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  653  	rcu_read_unlock();
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  654  	return exe_file;
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  655  }
b7ff0c42f1987b Guilherme G. Piccoli 2023-09-07  656  

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