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Commit e7fe7b5c authored by Dan Williams's avatar Dan Williams Committed by Linus Torvalds
Browse files

mm: replace pud_write with pud_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
   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: default avatarDan 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e4e40e02

arch/s390/include/asm/pgtable.h

+6 −0
Original line number Diff line number Diff line
@@ -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
Original line number Diff line number Diff line
@@ -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
Original line number Diff line number Diff line
@@ -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
Original line number Diff line number Diff line
@@ -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;