Subject: + frontswap-fix-incorrect-zeroing-and-allocation-size-for-frontswap_map.patch added to -mm tree
To: akinobu.mita@xxxxxxxxx,konrad.wilk@xxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 03 Jun 2013 16:31:31 -0700
The patch titled
Subject: frontswap: fix incorrect zeroing and allocation size for frontswap_map
has been added to the -mm tree. Its filename is
frontswap-fix-incorrect-zeroing-and-allocation-size-for-frontswap_map.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Subject: frontswap: fix incorrect zeroing and allocation size for frontswap_map
The bitmap accessed by bitops must have enough size to hold the required
numbers of bits rounded up to a multiple of BITS_PER_LONG. And the bitmap
must not be zeroed by memset() if the number of bits cleared is not a
multiple of BITS_PER_LONG.
This fixes incorrect zeroing and allocation size for frontswap_map. The
incorrect zeroing part doesn't cause any problem because frontswap_map is
freed just after zeroing. But the wrongly calculated allocation size may
cause the problem.
For 32bit systems, the allocation size of frontswap_map is about twice as
large as required size. For 64bit systems, the allocation size is smaller
than requeired if the number of bits is not a multiple of BITS_PER_LONG.
Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/frontswap.c | 2 +-
mm/swapfile.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff -puN mm/frontswap.c~frontswap-fix-incorrect-zeroing-and-allocation-size-for-frontswap_map mm/frontswap.c
--- a/mm/frontswap.c~frontswap-fix-incorrect-zeroing-and-allocation-size-for-frontswap_map
+++ a/mm/frontswap.c
@@ -319,7 +319,7 @@ void __frontswap_invalidate_area(unsigne
return;
frontswap_ops->invalidate_area(type);
atomic_set(&sis->frontswap_pages, 0);
- memset(sis->frontswap_map, 0, sis->max / sizeof(long));
+ bitmap_zero(sis->frontswap_map, sis->max);
}
clear_bit(type, need_init);
}
diff -puN mm/swapfile.c~frontswap-fix-incorrect-zeroing-and-allocation-size-for-frontswap_map mm/swapfile.c
--- a/mm/swapfile.c~frontswap-fix-incorrect-zeroing-and-allocation-size-for-frontswap_map
+++ a/mm/swapfile.c
@@ -2130,7 +2130,7 @@ SYSCALL_DEFINE2(swapon, const char __use
}
/* frontswap enabled? set up bit-per-page map for frontswap */
if (frontswap_enabled)
- frontswap_map = vzalloc(maxpages / sizeof(long));
+ frontswap_map = vzalloc(BITS_TO_LONGS(maxpages) * sizeof(long));
if (p->bdev) {
if (blk_queue_nonrot(bdev_get_queue(p->bdev))) {
_
Patches currently in -mm which might be from akinobu.mita@xxxxxxxxx are
linux-next.patch
frontswap-fix-incorrect-zeroing-and-allocation-size-for-frontswap_map.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
