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