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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.

[[email protected]: 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 <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Heiko Carstens <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Dan Williams authored and Linus Torvalds committed 2017-11-29 18:40:42 -08:00
1 parent e4e40e0263
commit e7fe7b5cae
4 files changed
+9 -3
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arch/s390/include/asm/pgtable.h
+6
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)) {
arch/sparc/mm/gup.c
+1 -1
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;
mm/huge_memory.c
+1 -1
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))
mm/memory.c
+1 -1
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;