summaryrefslogtreecommitdiffstats
path: root/arch/x86/mm/pgtable_32.c
diff options
context:
space:
mode:
authorDave Hansen <dave.hansen@linux.intel.com>2016-07-07 17:19:15 -0700
committerIngo Molnar <mingo@kernel.org>2016-07-13 09:43:25 +0200
commitdcb32d9913b7ed527b135a7e221f8d14b67bb952 (patch)
tree8a6f1a2fc60613780291a1a11b5bd62c5a238b77 /arch/x86/mm/pgtable_32.c
parente4a84be6f05eab4778732d799f63b3cd15427885 (diff)
downloadlinux-dcb32d9913b7ed527b135a7e221f8d14b67bb952.tar.bz2
x86/mm: Use pte_none() to test for empty PTE
The page table manipulation code seems to have grown a couple of sites that are looking for empty PTEs. Just in case one of these entries got a stray bit set, use pte_none() instead of checking for a zero pte_val(). The use pte_same() makes me a bit nervous. If we were doing a pte_same() check against two cleared entries and one of them had a stray bit set, it might fail the pte_same() check. But, I don't think we ever _do_ pte_same() for cleared entries. It is almost entirely used for checking for races in fault-in paths. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: dave.hansen@intel.com Cc: linux-mm@kvack.org Cc: mhocko@suse.com Link: http://lkml.kernel.org/r/20160708001915.813703D9@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm/pgtable_32.c')
-rw-r--r--arch/x86/mm/pgtable_32.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c
index 75cc0978d45d..e67ae0e6c59d 100644
--- a/arch/x86/mm/pgtable_32.c
+++ b/arch/x86/mm/pgtable_32.c
@@ -47,7 +47,7 @@ void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
return;
}
pte = pte_offset_kernel(pmd, vaddr);
- if (pte_val(pteval))
+ if (!pte_none(pteval))
set_pte_at(&init_mm, vaddr, pte, pteval);
else
pte_clear(&init_mm, vaddr, pte);