Re: [PATCH 4/4] mm/migration: fix potential pte_unmap on an not mapped pte

From: Miaohe Lin
Date: Sun Apr 10 2022 - 21:54:58 EST


On 2022/4/9 19:38, kernel test robot wrote:
> Hi Miaohe,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on hnaz-mm/master]
> [also build test ERROR on linus/master v5.18-rc1 next-20220408]
> [cannot apply to linux/master]
> [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/intel-lab-lkp/linux/commits/Miaohe-Lin/A-few-cleanup-and-fixup-patches-for-migration/20220409-154028
> base: https://github.com/hnaz/linux-mm master
> config: powerpc64-randconfig-r015-20220408 (https://download.01.org/0day-ci/archive/20220409/202204091914.psVO4TrI-lkp@xxxxxxxxx/config)
> compiler: powerpc64-linux-gcc (GCC) 11.2.0
> 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/intel-lab-lkp/linux/commit/73a982570cc62313c55cc5cbc2dd7acf40601474
> git remote add linux-review https://github.com/intel-lab-lkp/linux
> git fetch --no-tags linux-review Miaohe-Lin/A-few-cleanup-and-fixup-patches-for-migration/20220409-154028
> git checkout 73a982570cc62313c55cc5cbc2dd7acf40601474
> # save the config file to linux build tree
> mkdir build_dir
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/mm/
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>

Oh, powerpc variant is left undone. Will fix it. Thanks!

>
> All errors (new ones prefixed by >>):
>
> arch/powerpc/mm/hugetlbpage.c: In function 'follow_huge_pd':
>>> arch/powerpc/mm/hugetlbpage.c:537:25: error: too few arguments to function '__migration_entry_wait'
> 537 | __migration_entry_wait(mm, ptep, ptl);
> | ^~~~~~~~~~~~~~~~~~~~~~
> In file included from arch/powerpc/mm/hugetlbpage.c:20:
> include/linux/swapops.h:233:13: note: declared here
> 233 | extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
> | ^~~~~~~~~~~~~~~~~~~~~~
>
>
> vim +/__migration_entry_wait +537 arch/powerpc/mm/hugetlbpage.c
>
> ^1da177e4c3f41 arch/ppc64/mm/hugetlbpage.c Linus Torvalds 2005-04-16 507
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 508 struct page *follow_huge_pd(struct vm_area_struct *vma,
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 509 unsigned long address, hugepd_t hpd,
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 510 int flags, int pdshift)
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 511 {
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 512 pte_t *ptep;
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 513 spinlock_t *ptl;
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 514 struct page *page = NULL;
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 515 unsigned long mask;
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 516 int shift = hugepd_shift(hpd);
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 517 struct mm_struct *mm = vma->vm_mm;
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 518
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 519 retry:
> ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 520 /*
> ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 521 * hugepage directory entries are protected by mm->page_table_lock
> ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 522 * Use this instead of huge_pte_lockptr
> ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 523 */
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 524 ptl = &mm->page_table_lock;
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 525 spin_lock(ptl);
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 526
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 527 ptep = hugepte_offset(hpd, address, pdshift);
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 528 if (pte_present(*ptep)) {
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 529 mask = (1UL << shift) - 1;
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 530 page = pte_page(*ptep);
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 531 page += ((address & mask) >> PAGE_SHIFT);
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 532 if (flags & FOLL_GET)
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 533 get_page(page);
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 534 } else {
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 535 if (is_hugetlb_entry_migration(*ptep)) {
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 536 spin_unlock(ptl);
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 @537 __migration_entry_wait(mm, ptep, ptl);
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 538 goto retry;
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 539 }
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 540 }
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 541 spin_unlock(ptl);
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 542 return page;
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 543 }
> 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 544
>