diff options
| author | Andrey Vagin <avagin@openvz.org> | 2014-01-30 15:46:10 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-13 13:55:29 -0800 |
| commit | cc2e23b7577fab9465287702f5151cf0fd15c45b (patch) | |
| tree | 5ad0c27f9ab27e99d715baf699d63ecdf0526d18 /arch | |
| parent | 1140f8ce36b1cb82091eefc34d2fea953df30d25 (diff) | |
mm: don't lose the SOFT_DIRTY flag on mprotect
commit 24f91eba18bbfdb27e71a1aae5b3a61b67fcd091 upstream.
The SOFT_DIRTY bit shows that the content of memory was changed after a
defined point in the past. mprotect() doesn't change the content of
memory, so it must not change the SOFT_DIRTY bit.
This bug causes a malfunction: on the first iteration all pages are
dumped. On other iterations only pages with the SOFT_DIRTY bit are
dumped. So if the SOFT_DIRTY bit is cleared from a page by mistake, the
page is not dumped and its content will be restored incorrectly.
This patch does nothing with _PAGE_SWP_SOFT_DIRTY, becase pte_modify()
is called only for present pages.
Fixes commit 0f8975ec4db2 ("mm: soft-dirty bits for user memory changes
tracking").
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/pgtable_types.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 0ecac257fb26..840c127a938e 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -121,7 +121,8 @@ /* Set of bits not changed in pte_modify */ #define _PAGE_CHG_MASK (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT | \ - _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY) + _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY | \ + _PAGE_SOFT_DIRTY) #define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE) #define _PAGE_CACHE_MASK (_PAGE_PCD | _PAGE_PWT) |