|
 |
ab224c |
From f8c8218856effc43ea01cd9394761cfb8aeaa8df Mon Sep 17 00:00:00 2001
|
|
|
ab224c |
Message-Id: <f8c8218856effc43ea01cd9394761cfb8aeaa8df.1382423400.git.bhe@redhat.com>
|
|
|
ab224c |
In-Reply-To: <a785fa7dd7a7bd7dcbb017d0bea8848243b0924f.1382423400.git.bhe@redhat.com>
|
|
|
ab224c |
References: <a785fa7dd7a7bd7dcbb017d0bea8848243b0924f.1382423400.git.bhe@redhat.com>
|
|
|
ab224c |
From: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
|
|
|
ab224c |
Date: Thu, 12 Sep 2013 13:19:00 +0900
|
|
|
ab224c |
Subject: [PATCH 2/2] [PATCH] Use divideup() to calculate maximum required
|
|
|
ab224c |
bitmap size.
|
|
|
ab224c |
|
|
|
ab224c |
Currently, check_cyclic_buffer_overrun() wrongly calculates maximum
|
|
|
ab224c |
bitmap size required to represent maximum block size managed by buddy
|
|
|
ab224c |
allocator with roundup(). Then, max_block_size is BITPERBYTE-time
|
|
|
ab224c |
larger than its correct size. As a result, although the bug never
|
|
|
ab224c |
affect free-page filtering since roundup(max_order_nr_pages,
|
|
|
ab224c |
BITPERBYTE) is a multiple of divideup(max_order_nr_pages, BITPERBYTE),
|
|
|
ab224c |
the following sanity check, (max_block_size > info->bufsize_cyclic),
|
|
|
ab224c |
and recalculation of info->bufsize_cyclic becomes BITPERBYTE-time
|
|
|
ab224c |
conservative and inefficient.
|
|
|
ab224c |
|
|
|
ab224c |
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
|
|
|
ab224c |
---
|
|
|
ab224c |
makedumpfile.c | 5 ++---
|
|
|
ab224c |
1 file changed, 2 insertions(+), 3 deletions(-)
|
|
|
ab224c |
|
|
|
ab224c |
diff --git a/makedumpfile-1.5.4/makedumpfile.c b/makedumpfile-1.5.4/makedumpfile.c
|
|
|
ab224c |
index 164b3f1..1718f88 100644
|
|
|
ab224c |
--- a/makedumpfile-1.5.4/makedumpfile.c
|
|
|
ab224c |
+++ b/makedumpfile-1.5.4/makedumpfile.c
|
|
|
ab224c |
@@ -4078,10 +4078,9 @@ check_cyclic_buffer_overrun(void)
|
|
|
ab224c |
{
|
|
|
ab224c |
int max_order = ARRAY_LENGTH(zone.free_area);
|
|
|
ab224c |
int max_order_nr_pages = 1 << (max_order - 1);
|
|
|
ab224c |
- unsigned long max_block_size = roundup(max_order_nr_pages, BITPERBYTE);
|
|
|
ab224c |
+ unsigned long max_block_size = divideup(max_order_nr_pages, BITPERBYTE);
|
|
|
ab224c |
|
|
|
ab224c |
- if (info->bufsize_cyclic %
|
|
|
ab224c |
- roundup(max_order_nr_pages, BITPERBYTE)) {
|
|
|
ab224c |
+ if (info->bufsize_cyclic % max_block_size) {
|
|
|
ab224c |
unsigned long bufsize;
|
|
|
ab224c |
|
|
|
ab224c |
if (max_block_size > info->bufsize_cyclic) {
|
|
|
ab224c |
--
|
|
|
ab224c |
1.8.3.1
|
|
|
ab224c |
|