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authorDan Williams <dan.j.williams@intel.com>2017-11-30 01:10:18 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-30 03:40:42 +0100
commitc7da82b894e9eef60a04a15f065a8502341bf13b (patch)
treec59fd3cca98b6247bcd36f2cea370c3ce746b4e2 /fs
parentmm: replace pud_write with pud_access_permitted in fault + gup paths (diff)
downloadlinux-c7da82b894e9eef60a04a15f065a8502341bf13b.tar.xz
linux-c7da82b894e9eef60a04a15f065a8502341bf13b.zip
mm: replace pmd_write with pmd_access_permitted in fault + gup paths
The 'access_permitted' helper is used in the gup-fast path and goes beyond the simple _PAGE_RW check to also: - validate that the mapping is writable from a protection keys standpoint - validate that the pte has _PAGE_USER set since all fault paths where pmd_write is must be referencing user-memory. Link: http://lkml.kernel.org/r/151043111049.2842.15241454964150083466.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/dax.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/dax.c b/fs/dax.c
index 95981591977a..78b72c48374e 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -627,7 +627,8 @@ static void dax_mapping_entry_mkclean(struct address_space *mapping,
if (pfn != pmd_pfn(*pmdp))
goto unlock_pmd;
- if (!pmd_dirty(*pmdp) && !pmd_write(*pmdp))
+ if (!pmd_dirty(*pmdp)
+ && !pmd_access_permitted(*pmdp, WRITE))
goto unlock_pmd;
flush_cache_page(vma, address, pfn);