I have added VM_SOFTDIRTY to smatch_data/kernel.unconstant_macros to
silence this false positive.
regards,
dan carpenter
On Sat, May 10, 2014 at 08:57:51AM +0800, kbuild test robot wrote:
> TO: Cyrill Gorcunov <gorcu...@gmail.com>
> CC: Johannes Weiner <han...@cmpxchg.org>
> CC: Andrew Morton <a...@linux-foundation.org>
> CC: Linux Memory Management List <linux...@kvack.org>
>
> Hi Cyrill,
>
> First bad commit (maybe != root cause):
>
> tree: git://git.cmpxchg.org/linux-mmotm.git master
> head: 9567896580328249f6519fda78cf9fe185a8486d
> commit: 42e82fd9aa0a10d06a5642f8b83af8dc443f0e3a [192/459] mm: pgtable --
> Require X86_64 for soft-dirty tracker, v2
> :::::: branch date: 49 minutes ago
> :::::: commit date: 51 minutes ago
>
> fs/proc/task_mmu.c:769 clear_refs_test_walk() warn: bitwise AND condition is
> false here
> fs/proc/task_mmu.c:928 pte_to_pagemap_entry() warn: bitwise AND condition is
> false here
> fs/proc/task_mmu.c:936 pte_to_pagemap_entry() warn: bitwise AND condition is
> false here
> fs/proc/task_mmu.c:993 pagemap_pmd() warn: bitwise AND condition is false here
> fs/proc/task_mmu.c:1039 pagemap_hugetlb() warn: bitwise AND condition is
> false here
>
> git remote add mmotm git://git.cmpxchg.org/linux-mmotm.git
> git remote update mmotm
> git checkout 42e82fd9aa0a10d06a5642f8b83af8dc443f0e3a
> vim +769 fs/proc/task_mmu.c
>
> 436a162d3 Naoya Horiguchi 2014-05-10 763 */
> 436a162d3 Naoya Horiguchi 2014-05-10 764 if (cp->type ==
> CLEAR_REFS_ANON && vma->vm_file)
> 436a162d3 Naoya Horiguchi 2014-05-10 765 walk->skip = 1;
> 436a162d3 Naoya Horiguchi 2014-05-10 766 if (cp->type ==
> CLEAR_REFS_MAPPED && !vma->vm_file)
> 436a162d3 Naoya Horiguchi 2014-05-10 767 walk->skip = 1;
> 6041cafc9 Cyrill Gorcunov 2014-05-10 768 if (cp->type ==
> CLEAR_REFS_SOFT_DIRTY) {
> 6041cafc9 Cyrill Gorcunov 2014-05-10 @769 if
> (vma->vm_flags & VM_SOFTDIRTY)
> 6041cafc9 Cyrill Gorcunov 2014-05-10 770
> vma->vm_flags &= ~VM_SOFTDIRTY;
> 6041cafc9 Cyrill Gorcunov 2014-05-10 771 }
> a6198797c Matt Mackall 2008-02-04 772 return 0;
> a6198797c Matt Mackall 2008-02-04 773 }
> a6198797c Matt Mackall 2008-02-04 774
> f248dcb34 Matt Mackall 2008-02-04 775 static ssize_t
> clear_refs_write(struct file *file, const char __user *buf,
> f248dcb34 Matt Mackall 2008-02-04 776
> size_t count, loff_t *ppos)
> b813e931b David Rientjes 2007-05-06 777 {
> f248dcb34 Matt Mackall 2008-02-04 778 struct task_struct
> *task;
> fb92a4b06 Vincent Li 2009-09-22 779 char
> buffer[PROC_NUMBUF];
> f248dcb34 Matt Mackall 2008-02-04 780 struct mm_struct *mm;
> b813e931b David Rientjes 2007-05-06 781 struct vm_area_struct
> *vma;
> 040fa0207 Pavel Emelyanov 2013-07-03 782 enum clear_refs_types
> type;
> 040fa0207 Pavel Emelyanov 2013-07-03 783 int itype;
> 0a8cb8e34 Alexey Dobriyan 2011-05-26 784 int rv;
> b813e931b David Rientjes 2007-05-06 785
> f248dcb34 Matt Mackall 2008-02-04 786 memset(buffer, 0,
> sizeof(buffer));
> f248dcb34 Matt Mackall 2008-02-04 787 if (count >
> sizeof(buffer) - 1)
> f248dcb34 Matt Mackall 2008-02-04 788 count =
> sizeof(buffer) - 1;
> f248dcb34 Matt Mackall 2008-02-04 789 if
> (copy_from_user(buffer, buf, count))
> f248dcb34 Matt Mackall 2008-02-04 790 return -EFAULT;
> 040fa0207 Pavel Emelyanov 2013-07-03 791 rv =
> kstrtoint(strstrip(buffer), 10, &itype);
> 0a8cb8e34 Alexey Dobriyan 2011-05-26 792 if (rv < 0)
> 0a8cb8e34 Alexey Dobriyan 2011-05-26 793 return rv;
> 040fa0207 Pavel Emelyanov 2013-07-03 794 type = (enum
> clear_refs_types)itype;
> 040fa0207 Pavel Emelyanov 2013-07-03 795 if (type <
> CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
> f248dcb34 Matt Mackall 2008-02-04 796 return -EINVAL;
> 541c237c0 Pavel Emelyanov 2013-07-03 797
> 541c237c0 Pavel Emelyanov 2013-07-03 798 if (type ==
> CLEAR_REFS_SOFT_DIRTY) {
> 541c237c0 Pavel Emelyanov 2013-07-03 799
> soft_dirty_cleared = true;
> 6041cafc9 Cyrill Gorcunov 2014-05-10 800
> pr_warn_once("The pagemap bits 55-60 has changed their meaning!"
> 6041cafc9 Cyrill Gorcunov 2014-05-10 801 "
> See the linux/Documentation/vm/pagemap.txt for "
> 6041cafc9 Cyrill Gorcunov 2014-05-10 802
> "details.\n");
> 541c237c0 Pavel Emelyanov 2013-07-03 803 }
> 541c237c0 Pavel Emelyanov 2013-07-03 804
> 496ad9aa8 Al Viro 2013-01-23 805 task =
> get_proc_task(file_inode(file));
> f248dcb34 Matt Mackall 2008-02-04 806 if (!task)
> f248dcb34 Matt Mackall 2008-02-04 807 return -ESRCH;
> f248dcb34 Matt Mackall 2008-02-04 808 mm = get_task_mm(task);
> f248dcb34 Matt Mackall 2008-02-04 809 if (mm) {
> af9de7eb1 Pavel Emelyanov 2013-07-03 810 struct
> clear_refs_private cp = {
> 0f8975ec4 Pavel Emelyanov 2013-07-03 811 .type =
> type,
> af9de7eb1 Pavel Emelyanov 2013-07-03 812 };
> 20cbc9726 Andrew Morton 2008-07-05 813 struct mm_walk
> clear_refs_walk = {
> 436a162d3 Naoya Horiguchi 2014-05-10 814
> .pte_entry = clear_refs_pte,
> 436a162d3 Naoya Horiguchi 2014-05-10 815
> .test_walk = clear_refs_test_walk,
> 20cbc9726 Andrew Morton 2008-07-05 816 .mm =
> mm,
> af9de7eb1 Pavel Emelyanov 2013-07-03 817
> .private = &cp,
> 20cbc9726 Andrew Morton 2008-07-05 818 };
> f248dcb34 Matt Mackall 2008-02-04 819
> down_read(&mm->mmap_sem);
> 0f8975ec4 Pavel Emelyanov 2013-07-03 820 if (type ==
> CLEAR_REFS_SOFT_DIRTY)
> 0f8975ec4 Pavel Emelyanov 2013-07-03 821
> mmu_notifier_invalidate_range_start(mm, 0, -1);
> 436a162d3 Naoya Horiguchi 2014-05-10 822 for (vma =
> mm->mmap; vma; vma = vma->vm_next)
> 436a162d3 Naoya Horiguchi 2014-05-10 823
> walk_page_vma(vma, &clear_refs_walk);
> 0f8975ec4 Pavel Emelyanov 2013-07-03 824 if (type ==
> CLEAR_REFS_SOFT_DIRTY)
> 0f8975ec4 Pavel Emelyanov 2013-07-03 825
> mmu_notifier_invalidate_range_end(mm, 0, -1);
> f248dcb34 Matt Mackall 2008-02-04 826
> flush_tlb_mm(mm);
> f248dcb34 Matt Mackall 2008-02-04 827
> up_read(&mm->mmap_sem);
> f248dcb34 Matt Mackall 2008-02-04 828 mmput(mm);
> f248dcb34 Matt Mackall 2008-02-04 829 }
> f248dcb34 Matt Mackall 2008-02-04 830 put_task_struct(task);
> fb92a4b06 Vincent Li 2009-09-22 831
> fb92a4b06 Vincent Li 2009-09-22 832 return count;
> b813e931b David Rientjes 2007-05-06 833 }
> b813e931b David Rientjes 2007-05-06 834
> f248dcb34 Matt Mackall 2008-02-04 835 const struct file_operations
> proc_clear_refs_operations = {
> f248dcb34 Matt Mackall 2008-02-04 836 .write =
> clear_refs_write,
> 6038f373a Arnd Bergmann 2010-08-15 837 .llseek =
> noop_llseek,
> f248dcb34 Matt Mackall 2008-02-04 838 };
> f248dcb34 Matt Mackall 2008-02-04 839
> 092b50bac Naoya Horiguchi 2012-03-21 840 typedef struct {
> 092b50bac Naoya Horiguchi 2012-03-21 841 u64 pme;
> 092b50bac Naoya Horiguchi 2012-03-21 842 } pagemap_entry_t;
> 092b50bac Naoya Horiguchi 2012-03-21 843
> 85863e475 Matt Mackall 2008-02-04 844 struct pagemapread {
> 8c8296223 yonghua zheng 2013-08-13 845 int pos, len;
> /* units: PM_ENTRY_BYTES, not bytes */
> 092b50bac Naoya Horiguchi 2012-03-21 846 pagemap_entry_t *buffer;
> 2b0a9f017 Pavel Emelyanov 2013-07-03 847 bool v2;
> 85863e475 Matt Mackall 2008-02-04 848 };
> 85863e475 Matt Mackall 2008-02-04 849
> 5aaabe831 Naoya Horiguchi 2012-03-21 850 #define PAGEMAP_WALK_SIZE
> (PMD_SIZE)
> 5aaabe831 Naoya Horiguchi 2012-03-21 851 #define PAGEMAP_WALK_MASK
> (PMD_MASK)
> 5aaabe831 Naoya Horiguchi 2012-03-21 852
> 8c8296223 yonghua zheng 2013-08-13 853 #define PM_ENTRY_BYTES
> sizeof(pagemap_entry_t)
> f16278c67 Hans Rosenfeld 2008-03-21 854 #define PM_STATUS_BITS 3
> f16278c67 Hans Rosenfeld 2008-03-21 855 #define PM_STATUS_OFFSET
> (64 - PM_STATUS_BITS)
> f16278c67 Hans Rosenfeld 2008-03-21 856 #define PM_STATUS_MASK
> (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
> f16278c67 Hans Rosenfeld 2008-03-21 857 #define PM_STATUS(nr)
> (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
> f16278c67 Hans Rosenfeld 2008-03-21 858 #define PM_PSHIFT_BITS 6
> f16278c67 Hans Rosenfeld 2008-03-21 859 #define PM_PSHIFT_OFFSET
> (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
> f16278c67 Hans Rosenfeld 2008-03-21 860 #define PM_PSHIFT_MASK
> (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
> 2b0a9f017 Pavel Emelyanov 2013-07-03 861 #define __PM_PSHIFT(x)
> (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
> f16278c67 Hans Rosenfeld 2008-03-21 862 #define PM_PFRAME_MASK
> ((1LL << PM_PSHIFT_OFFSET) - 1)
> f16278c67 Hans Rosenfeld 2008-03-21 863 #define PM_PFRAME(x)
> ((x) & PM_PFRAME_MASK)
> 2b0a9f017 Pavel Emelyanov 2013-07-03 864 /* in "new" pagemap pshift
> bits are occupied with more status bits */
> 2b0a9f017 Pavel Emelyanov 2013-07-03 865 #define PM_STATUS2(v2, x)
> (__PM_PSHIFT(v2 ? x : PAGE_SHIFT))
> f16278c67 Hans Rosenfeld 2008-03-21 866
> 0f8975ec4 Pavel Emelyanov 2013-07-03 867 #define __PM_SOFT_DIRTY
> (1LL)
> f16278c67 Hans Rosenfeld 2008-03-21 868 #define PM_PRESENT
> PM_STATUS(4LL)
> f16278c67 Hans Rosenfeld 2008-03-21 869 #define PM_SWAP
> PM_STATUS(2LL)
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 870 #define PM_FILE
> PM_STATUS(1LL)
> 2b0a9f017 Pavel Emelyanov 2013-07-03 871 #define PM_NOT_PRESENT(v2)
> PM_STATUS2(v2, 0)
> 85863e475 Matt Mackall 2008-02-04 872 #define PM_END_OF_BUFFER 1
> 85863e475 Matt Mackall 2008-02-04 873
> 092b50bac Naoya Horiguchi 2012-03-21 874 static inline
> pagemap_entry_t make_pme(u64 val)
> 092b50bac Naoya Horiguchi 2012-03-21 875 {
> 092b50bac Naoya Horiguchi 2012-03-21 876 return
> (pagemap_entry_t) { .pme = val };
> 092b50bac Naoya Horiguchi 2012-03-21 877 }
> 092b50bac Naoya Horiguchi 2012-03-21 878
> 092b50bac Naoya Horiguchi 2012-03-21 879 static int
> add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
> 85863e475 Matt Mackall 2008-02-04 880
> struct pagemapread *pm)
> 85863e475 Matt Mackall 2008-02-04 881 {
> 092b50bac Naoya Horiguchi 2012-03-21 882 pm->buffer[pm->pos++] =
> *pme;
> d82ef020c KAMEZAWA Hiroyuki 2010-04-02 883 if (pm->pos >= pm->len)
> aae8679b0 Thomas Tuttle 2008-06-05 884 return
> PM_END_OF_BUFFER;
> 85863e475 Matt Mackall 2008-02-04 885 return 0;
> 85863e475 Matt Mackall 2008-02-04 886 }
> 85863e475 Matt Mackall 2008-02-04 887
> 85863e475 Matt Mackall 2008-02-04 888 static int
> pagemap_pte_hole(unsigned long start, unsigned long end,
> 2165009bd Dave Hansen 2008-06-12 889
> struct mm_walk *walk)
> 85863e475 Matt Mackall 2008-02-04 890 {
> 2165009bd Dave Hansen 2008-06-12 891 struct pagemapread *pm
> = walk->private;
> 85863e475 Matt Mackall 2008-02-04 892 unsigned long addr;
> 85863e475 Matt Mackall 2008-02-04 893 int err = 0;
> 2b0a9f017 Pavel Emelyanov 2013-07-03 894 pagemap_entry_t pme =
> make_pme(PM_NOT_PRESENT(pm->v2));
> 092b50bac Naoya Horiguchi 2012-03-21 895
> 85863e475 Matt Mackall 2008-02-04 896 for (addr = start; addr
> < end; addr += PAGE_SIZE) {
> 092b50bac Naoya Horiguchi 2012-03-21 897 err =
> add_to_pagemap(addr, &pme, pm);
> 85863e475 Matt Mackall 2008-02-04 898 if (err)
> 85863e475 Matt Mackall 2008-02-04 899 break;
> 85863e475 Matt Mackall 2008-02-04 900 }
> 85863e475 Matt Mackall 2008-02-04 901 return err;
> 85863e475 Matt Mackall 2008-02-04 902 }
> 85863e475 Matt Mackall 2008-02-04 903
> 2b0a9f017 Pavel Emelyanov 2013-07-03 904 static void
> pte_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 905 struct
> vm_area_struct *vma, unsigned long addr, pte_t pte)
> 85863e475 Matt Mackall 2008-02-04 906 {
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 907 u64 frame, flags;
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 908 struct page *page =
> NULL;
> 0f8975ec4 Pavel Emelyanov 2013-07-03 909 int flags2 = 0;
> 85863e475 Matt Mackall 2008-02-04 910
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 911 if (pte_present(pte)) {
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 912 frame =
> pte_pfn(pte);
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 913 flags =
> PM_PRESENT;
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 914 page =
> vm_normal_page(vma, addr, pte);
> e9cdd6e77 Cyrill Gorcunov 2013-10-16 915 if
> (pte_soft_dirty(pte))
> e9cdd6e77 Cyrill Gorcunov 2013-10-16 916 flags2
> |= __PM_SOFT_DIRTY;
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 917 } else if
> (is_swap_pte(pte)) {
> 179ef71cb Cyrill Gorcunov 2013-08-13 918 swp_entry_t
> entry;
> 179ef71cb Cyrill Gorcunov 2013-08-13 919 if
> (pte_swp_soft_dirty(pte))
> 179ef71cb Cyrill Gorcunov 2013-08-13 920 flags2
> |= __PM_SOFT_DIRTY;
> 179ef71cb Cyrill Gorcunov 2013-08-13 921 entry =
> pte_to_swp_entry(pte);
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 922 frame =
> swp_type(entry) |
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 923
> (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 924 flags = PM_SWAP;
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 925 if
> (is_migration_entry(entry))
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 926 page =
> migration_entry_to_page(entry);
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 927 } else {
> d9104d1ca Cyrill Gorcunov 2013-09-11 @928 if
> (vma->vm_flags & VM_SOFTDIRTY)
> d9104d1ca Cyrill Gorcunov 2013-09-11 929 flags2
> |= __PM_SOFT_DIRTY;
> d9104d1ca Cyrill Gorcunov 2013-09-11 930 *pme =
> make_pme(PM_NOT_PRESENT(pm->v2) | PM_STATUS2(pm->v2, flags2));
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 931 return;
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 932 }
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 933
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 934 if (page &&
> !PageAnon(page))
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 935 flags |=
> PM_FILE;
> e9cdd6e77 Cyrill Gorcunov 2013-10-16 @936 if ((vma->vm_flags &
> VM_SOFTDIRTY))
> 0f8975ec4 Pavel Emelyanov 2013-07-03 937 flags2 |=
> __PM_SOFT_DIRTY;
> 052fb0d63 Konstantin Khlebnikov 2012-05-31 938
> 0f8975ec4 Pavel Emelyanov 2013-07-03 939 *pme =
> make_pme(PM_PFRAME(frame) | PM_STATUS2(pm->v2, flags2) | flags);
>
> :::::: The code at line 769 was first introduced by commit
> :::::: 6041cafc9faf096d9c4a89d4ef04074183950c1c mm: softdirty: clear
> VM_SOFTDIRTY flag inside clear_refs_write() instead of clear_soft_dirty()
>
> :::::: TO: Cyrill Gorcunov <gorcu...@openvz.org>
> :::::: CC: Johannes Weiner <han...@cmpxchg.org>
>
> ---
> 0-DAY kernel build testing backend Open Source Technology Center
> http://lists.01.org/mailman/listinfo/kbuild Intel Corporation
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