mm: use READ_ONCE() for non-scalar types

Commit 38c5ce936a ("mm/gup: Replace ACCESS_ONCE with READ_ONCE")
converted ACCESS_ONCE usage in gup_pmd_range() to READ_ONCE, since
ACCESS_ONCE doesn't work reliably on non-scalar types.

This patch also fixes the other ACCESS_ONCE usages in gup_pte_range()
and __get_user_pages_fast() in mm/gup.c

Signed-off-by: Jason Low <jason.low2@hp.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@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:
Jason Low 2015-04-15 16:14:05 -07:00 committed by Linus Torvalds
parent 6cd576130b
commit 9d8c47e4bb
1 changed files with 2 additions and 2 deletions

View File

@ -1019,7 +1019,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
*
* for an example see gup_get_pte in arch/x86/mm/gup.c
*/
pte_t pte = ACCESS_ONCE(*ptep);
pte_t pte = READ_ONCE(*ptep);
struct page *page;
/*
@ -1309,7 +1309,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
local_irq_save(flags);
pgdp = pgd_offset(mm, addr);
do {
pgd_t pgd = ACCESS_ONCE(*pgdp);
pgd_t pgd = READ_ONCE(*pgdp);
next = pgd_addr_end(addr, end);
if (pgd_none(pgd))