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authorYang Shi <yang.shi@linux.alibaba.com>2019-03-29 03:43:55 (GMT)
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-05 20:29:05 (GMT)
commitd59794af892d2987fb4283ef0605417c6547bff6 (patch)
tree2e041d0be9a36a386ac2243fa1fceeea3d4fd57e
parent0668f0d6874088e7fca49c60703e1aa732616d4e (diff)
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mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified
commit a7f40cfe3b7ada57af9b62fd28430eeb4a7cfcb7 upstream. When MPOL_MF_STRICT was specified and an existing page was already on a node that does not follow the policy, mbind() should return -EIO. But commit 6f4576e3687b ("mempolicy: apply page table walker on queue_pages_range()") broke the rule. And commit c8633798497c ("mm: mempolicy: mbind and migrate_pages support thp migration") didn't return the correct value for THP mbind() too. If MPOL_MF_STRICT is set, ignore vma_migratable() to make sure it reaches queue_pages_to_pte_range() or queue_pages_pmd() to check if an existing page was already on a node that does not follow the policy. And, non-migratable vma may be used, return -EIO too if MPOL_MF_MOVE or MPOL_MF_MOVE_ALL was specified. Tested with https://github.com/metan-ucw/ltp/blob/master/testcases/kernel/syscalls/mbind/mbind02.c [akpm@linux-foundation.org: tweak code comment] Link: http://lkml.kernel.org/r/1553020556-38583-1-git-send-email-yang.shi@linux.alibaba.com Fixes: 6f4576e3687b ("mempolicy: apply page table walker on queue_pages_range()") Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> Reported-by: Cyril Hrubis <chrubis@suse.cz> Suggested-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: Rafael Aquini <aquini@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Rientjes <rientjes@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat
-rw-r--r--mm/mempolicy.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 593b74b..5cb5147 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -547,11 +547,16 @@ retry:
goto retry;
}
- migrate_page_add(page, qp->pagelist, flags);
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
+ if (!vma_migratable(vma))
+ break;
+ migrate_page_add(page, qp->pagelist, flags);
+ } else
+ break;
}
pte_unmap_unlock(pte - 1, ptl);
cond_resched();
- return 0;
+ return addr != end ? -EIO : 0;
}
static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
@@ -623,7 +628,12 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end,
unsigned long endvma = vma->vm_end;
unsigned long flags = qp->flags;
- if (!vma_migratable(vma))
+ /*
+ * Need check MPOL_MF_STRICT to return -EIO if possible
+ * regardless of vma_migratable
+ */
+ if (!vma_migratable(vma) &&
+ !(flags & MPOL_MF_STRICT))
return 1;
if (endvma > end)
@@ -650,7 +660,7 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end,
}
/* queue pages from current vma */
- if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
+ if (flags & MPOL_MF_VALID)
return 0;
return 1;
}