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mm: replace pud_write with pud_access_permitted in fault + gup paths

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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
   pud_write is must be referencing user-memory.

[dan.j.williams@intel.com: fix powerpc compile error]
  Link: http://lkml.kernel.org/r/151129127237.37405.16073414520854722485.stgit@dwillia2-desk3.amr.corp.intel.com
Link: http://lkml.kernel.org/r/151043110453.2842.2166049702068628177.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: "David S. Miller" <davem@davemloft.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Dan Williams
2017-11-29 16:10:14 -08:00
committed by Linus Torvalds
parent e4e40e0263
commit e7fe7b5cae
4 changed files with 9 additions and 3 deletions
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2
arch/sparc/mm/gup.c
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@@ -114,7 +114,7 @@ static int gup_huge_pud(pud_t *pudp, pud_t pud, unsigned long addr,
if (!(pud_val(pud) & _PAGE_VALID))
return 0;
if (write && !pud_write(pud))
if (!pud_access_permitted(pud, write))
return 0;
refs = 0;