Re: [PATCH 36/43] x86: kmsan: sync metadata pages on page fault

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

Hi Alexander,

I love your patch! Perhaps something to improve:

[auto build test WARNING on tip/x86/mm]
[also build test WARNING on linus/master v5.16-rc5]
[cannot apply to tip/x86/core hnaz-mm/master next-20211213]
[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]

url:    https://github.com/0day-ci/linux/commits/Alexander-Potapenko/Add-KernelMemorySanitizer-infrastructure/20211215-003033
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 35fa745286ac44ee26ed100c2bd2553368ad193b
config: i386-randconfig-r015-20211214 (https://download.01.org/0day-ci/archive/20211215/202112150621.jBfij0NA-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project b6a2ddb6c8ac29412b1361810972e15221fa021c)
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/b9eff579426967ca933560818b165769b449377b
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Alexander-Potapenko/Add-KernelMemorySanitizer-infrastructure/20211215-003033
        git checkout b9eff579426967ca933560818b165769b449377b
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/mm/

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 >>):

>> arch/x86/mm/fault.c:263:6: warning: no previous prototype for function '__arch_sync_kernel_mappings' [-Wmissing-prototypes]
   void __arch_sync_kernel_mappings(unsigned long start, unsigned long end)
        ^
   arch/x86/mm/fault.c:263:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void __arch_sync_kernel_mappings(unsigned long start, unsigned long end)
   ^
   static 
   arch/x86/mm/fault.c:299:28: error: use of undeclared identifier 'KMSAN_VMALLOC_SHADOW_START'
                           start - VMALLOC_START + KMSAN_VMALLOC_SHADOW_START,
                                                   ^
   arch/x86/mm/fault.c:300:26: error: use of undeclared identifier 'KMSAN_VMALLOC_SHADOW_START'
                           end - VMALLOC_START + KMSAN_VMALLOC_SHADOW_START);
                                                 ^
   arch/x86/mm/fault.c:302:28: error: use of undeclared identifier 'KMSAN_VMALLOC_ORIGIN_START'
                           start - VMALLOC_START + KMSAN_VMALLOC_ORIGIN_START,
                                                   ^
   arch/x86/mm/fault.c:303:26: error: use of undeclared identifier 'KMSAN_VMALLOC_ORIGIN_START'
                           end - VMALLOC_START + KMSAN_VMALLOC_ORIGIN_START);
                                                 ^
   1 warning and 4 errors generated.


vim +/__arch_sync_kernel_mappings +263 arch/x86/mm/fault.c

   262	
 > 263	void __arch_sync_kernel_mappings(unsigned long start, unsigned long end)
   264	{
   265		unsigned long addr;
   266	
   267		for (addr = start & PMD_MASK;
   268		     addr >= TASK_SIZE_MAX && addr < VMALLOC_END;
   269		     addr += PMD_SIZE) {
   270			struct page *page;
   271	
   272			spin_lock(&pgd_lock);
   273			list_for_each_entry(page, &pgd_list, lru) {
   274				spinlock_t *pgt_lock;
   275	
   276				/* the pgt_lock only for Xen */
   277				pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
   278	
   279				spin_lock(pgt_lock);
   280				vmalloc_sync_one(page_address(page), addr);
   281				spin_unlock(pgt_lock);
   282			}
   283			spin_unlock(&pgd_lock);
   284		}
   285	}
   286	

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