Re: [PATCH 1/3] mm: handle_mm_fault_one()

From: kernel test robot
Date: Thu May 11 2023 - 23:52:44 EST


Hi Peter,

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/Peter-Xu/mm-handle_mm_fault_one/20230512-081554
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/ZF2E6i4pqJr7m436%40x1n
patch subject: [PATCH 1/3] mm: handle_mm_fault_one()
config: x86_64-randconfig-a013 (https://download.01.org/0day-ci/archive/20230512/202305121115.gTte4W7A-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build):
# https://github.com/intel-lab-lkp/linux/commit/0a03a4870c8a62e3ba52a0f9b50b307f509acb2b
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Peter-Xu/mm-handle_mm_fault_one/20230512-081554
git checkout 0a03a4870c8a62e3ba52a0f9b50b307f509acb2b
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 O=build_dir ARCH=x86_64 olddefconfig
make W=1 O=build_dir ARCH=x86_64 prepare

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202305121115.gTte4W7A-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>):

In file included from include/linux/memcontrol.h:20,
from include/linux/swap.h:9,
from include/linux/suspend.h:5,
from arch/x86/kernel/asm-offsets.c:14:
include/linux/mm.h: In function 'mm_should_release_mmap':
>> include/linux/mm.h:2371:13: error: 'fault' undeclared (first use in this function)
2371 | if (fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED))
| ^~~~~
include/linux/mm.h:2371:13: note: each undeclared identifier is reported only once for each function it appears in
include/linux/mm.h: In function 'handle_mm_fault_one':
>> include/linux/mm.h:2396:34: error: 'mm' undeclared (first use in this function); did you mean 'tm'?
2396 | mmap_read_unlock(mm);
| ^~
| tm
make[2]: *** [scripts/Makefile.build:114: arch/x86/kernel/asm-offsets.s] Error 1
make[2]: Target 'prepare' not remade because of errors.
make[1]: *** [Makefile:1287: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:226: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.


vim +/fault +2371 include/linux/mm.h

2362
2363 static inline bool
2364 mm_should_release_mmap(unsigned long flags, vm_fault_t retval)
2365 {
2366 /* The caller explicitly requested to keep the mmap read lock */
2367 if (flags & FAULT_FLAG_RETRY_NOWAIT)
2368 return false;
2369
2370 /* If the mmap read lock is already released, we're all good */
> 2371 if (fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED))
2372 return false;
2373
2374 /* Otherwise always release it */
2375 return true;
2376 }
2377
2378 /*
2379 * This is mostly handle_mm_fault(), but it also take care of releasing
2380 * mmap or vma read lock as long as possible (e.g. when !RETRY_NOWAIT).
2381 *
2382 * Normally it's the case when we got a hardware page fault, where we want
2383 * to release the lock right after the page fault. And it's not for case
2384 * like GUP where it can fault a range of pages continuously with mmap lock
2385 * being held during the process.
2386 */
2387 static inline vm_fault_t
2388 handle_mm_fault_one(struct vm_area_struct *vma, unsigned long address,
2389 unsigned int flags, struct pt_regs *regs)
2390 {
2391 vm_fault_t retval = handle_mm_fault(vma, address, flags, regs);
2392
2393 if (flags & FAULT_FLAG_VMA_LOCK)
2394 vma_end_read(vma);
2395 else if (mm_should_release_mmap(flags, retval))
> 2396 mmap_read_unlock(mm);
2397
2398 return retval;
2399 }
2400

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https://github.com/intel/lkp-tests