Re: [PATCH 08/12] arch, mm/util: add const to arch_pick_mmap_layout() parameter

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

Hi Max,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Max-Kellermann/mm-shmem-add-const-to-lots-of-pointer-parameters/20250830-023442
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20250829183159.2223948-9-max.kellermann%40ionos.com
patch subject: [PATCH 08/12] arch, mm/util: add const to arch_pick_mmap_layout() parameter
config: s390-allnoconfig (https://download.01.org/0day-ci/archive/20250830/202508302325.b9umktOw-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project ac23f7465eedd0dd565ffb201f573e7a69695fa3)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250830/202508302325.b9umktOw-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/202508302325.b9umktOw-lkp@intel.com/

All errors (new ones prefixed by >>):

>> arch/s390/mm/mmap.c:187:44: error: passing 'const struct rlimit *' to parameter of type 'struct rlimit *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
     187 |                 mm->mmap_base = mmap_base(random_factor, rlim_stack);
         |                                                          ^~~~~~~~~~
   arch/s390/mm/mmap.c:50:26: note: passing argument to parameter 'rlim_stack' here
      50 |                                       struct rlimit *rlim_stack)
         |                                                      ^
   1 error generated.


vim +187 arch/s390/mm/mmap.c

9b11c7912d00d0 Martin Schwidefsky 2017-04-24  167  
6252d702c5311c Martin Schwidefsky 2008-02-09  168  /*
6252d702c5311c Martin Schwidefsky 2008-02-09  169   * This function, called very early during the creation of a new
6252d702c5311c Martin Schwidefsky 2008-02-09  170   * process VM image, sets up which VM layout function to use:
6252d702c5311c Martin Schwidefsky 2008-02-09  171   */
f547a726bf8dd8 Max Kellermann     2025-08-29  172  void arch_pick_mmap_layout(struct mm_struct *mm, const struct rlimit *rlim_stack)
6252d702c5311c Martin Schwidefsky 2008-02-09  173  {
8e89a356feb6f1 Kees Cook          2015-04-14  174  	unsigned long random_factor = 0UL;
8e89a356feb6f1 Kees Cook          2015-04-14  175  
8e89a356feb6f1 Kees Cook          2015-04-14  176  	if (current->flags & PF_RANDOMIZE)
2b68f6caeac271 Kees Cook          2015-04-14  177  		random_factor = arch_mmap_rnd();
8e89a356feb6f1 Kees Cook          2015-04-14  178  
6252d702c5311c Martin Schwidefsky 2008-02-09  179  	/*
6252d702c5311c Martin Schwidefsky 2008-02-09  180  	 * Fall back to the standard layout if the personality
6252d702c5311c Martin Schwidefsky 2008-02-09  181  	 * bit is set, or if the expected stack growth is unlimited:
6252d702c5311c Martin Schwidefsky 2008-02-09  182  	 */
8f2af155b51358 Kees Cook          2018-04-10  183  	if (mmap_is_legacy(rlim_stack)) {
8e89a356feb6f1 Kees Cook          2015-04-14  184  		mm->mmap_base = mmap_base_legacy(random_factor);
40ae96eabea408 Lorenzo Stoakes    2025-08-12  185  		mm_flags_clear(MMF_TOPDOWN, mm);
6252d702c5311c Martin Schwidefsky 2008-02-09  186  	} else {
8f2af155b51358 Kees Cook          2018-04-10 @187  		mm->mmap_base = mmap_base(random_factor, rlim_stack);
c52d638d6b5da2 Lorenzo Stoakes    2025-08-13  188  		mm_flags_set(MMF_TOPDOWN, mm);
6252d702c5311c Martin Schwidefsky 2008-02-09  189  	}
6252d702c5311c Martin Schwidefsky 2008-02-09  190  }
fd5d210fa66bee Anshuman Khandual  2022-07-11  191  

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