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author | Dan Williams <dan.j.williams@intel.com> | 2017-11-30 03:10:18 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-30 05:40:42 +0300 |
commit | c7da82b894e9eef60a04a15f065a8502341bf13b (patch) | |
tree | c59fd3cca98b6247bcd36f2cea370c3ce746b4e2 /fs/dax.c | |
parent | e7fe7b5cae90cf85bb6fed5ec5d4c5cf311a4fe9 (diff) | |
download | linux-c7da82b894e9eef60a04a15f065a8502341bf13b.tar.xz |
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/dax.c')
-rw-r--r-- | fs/dax.c | 3 |
1 files changed, 2 insertions, 1 deletions
@@ -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); |