From: kernel test robot <lkp@intel.com>
To: kbuild@lists.01.org
Subject: Re: [PATCH v2 2/5] mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables
Date: Tue, 20 Apr 2021 05:52:45 +0800 [thread overview]
Message-ID: <202104200508.9rCLUHPp-lkp@intel.com> (raw)
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CC: kbuild-all(a)lists.01.org
In-Reply-To: <20210419135443.12822-3-david@redhat.com>
References: <20210419135443.12822-3-david@redhat.com>
TO: David Hildenbrand <david@redhat.com>
TO: linux-kernel(a)vger.kernel.org
CC: linux-mm(a)kvack.org
CC: David Hildenbrand <david@redhat.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linux Memory Management List <linux-mm@kvack.org>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Michal Hocko <mhocko@suse.com>
CC: Oscar Salvador <osalvador@suse.de>
CC: Matthew Wilcox <willy@infradead.org>
CC: Andrea Arcangeli <aarcange@redhat.com>
Hi David,
I love your patch! Perhaps something to improve:
[auto build test WARNING on kselftest/next]
[also build test WARNING on linux/master linus/master v5.12-rc8]
[cannot apply to hnaz-linux-mm/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/0day-ci/linux/commits/David-Hildenbrand/mm-madvise-introduce-MADV_POPULATE_-READ-WRITE-to-prefault-page-tables/20210419-220043
base: https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git next
:::::: branch date: 8 hours ago
:::::: commit date: 8 hours ago
config: i386-randconfig-m021-20210419 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
smatch warnings:
mm/madvise.c:845 madvise_populate() warn: variable dereferenced before check 'vma' (see line 833)
vim +/vma +845 mm/madvise.c
^1da177e4c3f415 Linus Torvalds 2005-04-16 826
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 827 static long madvise_populate(struct vm_area_struct *vma,
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 828 struct vm_area_struct **prev,
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 829 unsigned long start, unsigned long end,
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 830 int behavior)
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 831 {
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 832 const bool write = behavior == MADV_POPULATE_WRITE;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 @833 struct mm_struct *mm = vma->vm_mm;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 834 unsigned long tmp_end;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 835 int locked = 1;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 836 long pages;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 837
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 838 *prev = vma;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 839
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 840 while (start < end) {
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 841 /*
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 842 * We might have temporarily dropped the lock. For example,
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 843 * our VMA might have been split.
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 844 */
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 @845 if (!vma || start >= vma->vm_end) {
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 846 vma = find_vma(mm, start);
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 847 if (!vma || start < vma->vm_start)
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 848 return -ENOMEM;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 849 }
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 850
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 851 tmp_end = min_t(unsigned long, end, vma->vm_end);
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 852 /* Populate (prefault) page tables readable/writable. */
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 853 pages = faultin_vma_page_range(vma, start, tmp_end, write,
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 854 &locked);
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 855 if (!locked) {
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 856 mmap_read_lock(mm);
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 857 locked = 1;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 858 *prev = NULL;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 859 vma = NULL;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 860 }
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 861 if (pages < 0) {
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 862 switch (pages) {
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 863 case -EINTR:
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 864 return -EINTR;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 865 case -EFAULT: /* Incompatible mappings / permissions. */
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 866 return -EINVAL;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 867 case -EHWPOISON:
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 868 return -EHWPOISON;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 869 default:
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 870 pr_warn_once("%s: unhandled return value: %ld\n",
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 871 __func__, pages);
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 872 fallthrough;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 873 case -ENOMEM:
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 874 return -ENOMEM;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 875 }
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 876 }
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 877 start += pages * PAGE_SIZE;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 878 }
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 879 return 0;
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 880 }
b2cabf1f27bbe5d David Hildenbrand 2021-04-19 881
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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next reply other threads:[~2021-04-19 21:52 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-19 21:52 kernel test robot [this message]
-- strict thread matches above, loose matches on Subject: below --
2021-04-19 13:54 [PATCH v2 0/5] mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables David Hildenbrand
[not found] ` <20210419135443.12822-1-david-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2021-04-19 13:54 ` [PATCH v2 2/5] " David Hildenbrand
2021-04-19 13:54 ` David Hildenbrand
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