Re: [PATCH 2/2] mm/madvise: Use set_pte() to write page tables

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

Hi Samuel,

kernel test robot noticed the following build errors:

[auto build test ERROR on d358e5254674b70f34c847715ca509e46eb81e6f]

url:    https://github.com/intel-lab-lkp/linux/commits/Samuel-Holland/mm-debug_vm_pgtable-Use-set_pXd-to-write-page-tables/20251211-161254
base:   d358e5254674b70f34c847715ca509e46eb81e6f
patch link:    https://lore.kernel.org/r/20251211081117.1126521-3-samuel.holland%40sifive.com
patch subject: [PATCH 2/2] mm/madvise: Use set_pte() to write page tables
config: arm-footbridge_defconfig (https://download.01.org/0day-ci/archive/20251212/202512120735.ge1E0s5N-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251212/202512120735.ge1E0s5N-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/202512120735.ge1E0s5N-lkp@intel.com/

All errors (new ones prefixed by >>):

>> mm/madvise.c:1117:2: error: call to undeclared function 'set_pte'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1117 |         set_pte(ptep, make_pte_marker(PTE_MARKER_GUARD));
         |         ^
   mm/madvise.c:1117:2: note: did you mean 'set_ptes'?
   arch/arm/include/asm/pgtable.h:212:6: note: 'set_ptes' declared here
     212 | void set_ptes(struct mm_struct *mm, unsigned long addr,
         |      ^
   1 error generated.


vim +/set_pte +1117 mm/madvise.c

  1110	
  1111	static int guard_install_set_pte(unsigned long addr, unsigned long next,
  1112					 pte_t *ptep, struct mm_walk *walk)
  1113	{
  1114		unsigned long *nr_pages = (unsigned long *)walk->private;
  1115	
  1116		/* Simply install a PTE marker, this causes segfault on access. */
> 1117		set_pte(ptep, make_pte_marker(PTE_MARKER_GUARD));
  1118		(*nr_pages)++;
  1119	
  1120		return 0;
  1121	}
  1122	

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