diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2017-11-29 16:10:18 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-29 18:40:42 -0800 |
| commit | c7da82b894e9eef60a04a15f065a8502341bf13b (patch) | |
| tree | c59fd3cca98b6247bcd36f2cea370c3ce746b4e2 /mm/huge_memory.c | |
| parent | e7fe7b5cae90cf85bb6fed5ec5d4c5cf311a4fe9 (diff) | |
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 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 4fe2491056a0..05b729f45e8a 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -877,7 +877,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, */ WARN_ONCE(flags & FOLL_COW, "mm: In follow_devmap_pmd with FOLL_COW set"); - if (flags & FOLL_WRITE && !pmd_write(*pmd)) + if (!pmd_access_permitted(*pmd, flags & FOLL_WRITE)) return NULL; if (pmd_present(*pmd) && pmd_devmap(*pmd)) @@ -1393,7 +1393,7 @@ out_unlock: */ static inline bool can_follow_write_pmd(pmd_t pmd, unsigned int flags) { - return pmd_write(pmd) || + return pmd_access_permitted(pmd, WRITE) || ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pmd_dirty(pmd)); } |