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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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6
arch/s390/include/asm/pgtable.h
View file

@ -1264,6 +1264,12 @@ static inline pud_t pud_mkwrite(pud_t pud)
return pud;
}
#define pud_write pud_write
static inline int pud_write(pud_t pud)
{
return (pud_val(pud) & _REGION3_ENTRY_WRITE) != 0;
}
static inline pud_t pud_mkclean(pud_t pud)
{
if (pud_large(pud)) {

2
arch/sparc/mm/gup.c
View file

@ -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;

2
mm/huge_memory.c
View file

@ -1019,7 +1019,7 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
assert_spin_locked(pud_lockptr(mm, pud));
if (flags & FOLL_WRITE && !pud_write(*pud))
if (!pud_access_permitted(*pud, flags & FOLL_WRITE))
return NULL;
if (pud_present(*pud) && pud_devmap(*pud))

2
mm/memory.c
View file

@ -4013,7 +4013,7 @@ static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
/* NUMA case for anonymous PUDs would go here */
if (dirty && !pud_write(orig_pud)) {
if (dirty && !pud_access_permitted(orig_pud, WRITE)) {
ret = wp_huge_pud(&vmf, orig_pud);
if (!(ret & VM_FAULT_FALLBACK))
return ret;