kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

[S390] fix get_user_pages_fast

Browse source 
The check for the _PAGE_RO bit in get_user_pages_fast for write==1 is
the wrong way around. It must not be set for the fast path.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2010-11-10 10:05:51 +01:00 committed by Martin Schwidefsky
parent f6614b7bb4
commit 25591b0703
1 changed files with 3 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
arch/s390/mm/gup.c
View file

@ -20,18 +20,17 @@
static inline int gup_pte_range(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{
unsigned long mask, result;
unsigned long mask;
pte_t *ptep, pte;
struct page *page;
result = write ? 0 : _PAGE_RO;
mask = result | _PAGE_INVALID | _PAGE_SPECIAL;
mask = (write ? _PAGE_RO : 0) | _PAGE_INVALID | _PAGE_SPECIAL;
ptep = ((pte_t *) pmd_deref(pmd)) + pte_index(addr);
do {
pte = *ptep;
barrier();
if ((pte_val(pte) & mask) != result)
if ((pte_val(pte) & mask) != 0)
return 0;
VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
page = pte_page(pte);