Re: [PATCH] mm/vmalloc: clarify why vmap_range_noflush() might sleep

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

Hi Brendan,

kernel test robot noticed the following build errors:

[auto build test ERROR on ecc46e02e0abe025a6e840cba2d647f23fd1d721]

url:    https://github.com/intel-lab-lkp/linux/commits/Brendan-Jackman/mm-vmalloc-clarify-why-vmap_range_noflush-might-sleep/20251208-132202
base:   ecc46e02e0abe025a6e840cba2d647f23fd1d721
patch link:    https://lore.kernel.org/r/20251208-b4-vmalloc-might_alloc-v1-1-94a9bb8ecb08%40google.com
patch subject: [PATCH] mm/vmalloc: clarify why vmap_range_noflush() might sleep
config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20251209/202512090959.BWqYaOOg-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251209/202512090959.BWqYaOOg-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/202512090959.BWqYaOOg-lkp@intel.com/

All errors (new ones prefixed by >>):

>> mm/vmalloc.c:308:14: error: use of undeclared identifier 'GFP_PGTABLE_KERNEL'
     308 |         might_alloc(GFP_PGTABLE_KERNEL);
         |                     ^
   1 error generated.


vim +/GFP_PGTABLE_KERNEL +308 mm/vmalloc.c

   297	
   298	static int vmap_range_noflush(unsigned long addr, unsigned long end,
   299				phys_addr_t phys_addr, pgprot_t prot,
   300				unsigned int max_page_shift)
   301	{
   302		pgd_t *pgd;
   303		unsigned long start;
   304		unsigned long next;
   305		int err;
   306		pgtbl_mod_mask mask = 0;
   307	
 > 308		might_alloc(GFP_PGTABLE_KERNEL);
   309		BUG_ON(addr >= end);
   310	
   311		start = addr;
   312		pgd = pgd_offset_k(addr);
   313		do {
   314			next = pgd_addr_end(addr, end);
   315			err = vmap_p4d_range(pgd, addr, next, phys_addr, prot,
   316						max_page_shift, &mask);
   317			if (err)
   318				break;
   319		} while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
   320	
   321		if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
   322			arch_sync_kernel_mappings(start, end);
   323	
   324		return err;
   325	}
   326	

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