Commit c9690998 authored Jun 08, 2009 by Andreas Herrmann Committed by Ingo Molnar Jun 08, 2009

x86: memtest: remove 64-bit division

Using gcc 3.3.5 a "make allmodconfig" + "CONFIG_KVM=n"
triggers a build error:

 arch/x86/mm/built-in.o(.init.text+0x43f7): In function `__change_page_attr':
 arch/x86/mm/pageattr.c:114: undefined reference to `__udivdi3'
 make: *** [.tmp_vmlinux1] Error 1

The culprit turned out to be a division in arch/x86/mm/memtest.c
For more info see this thread:

  http://marc.info/?l=linux-kernel&m=124416232620683



The patch entirely removes the division that caused the build
error.

[ Impact: build fix with certain GCC versions ]

Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: xiyou.wangcong@gmail.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org>
LKML-Reference: <20090608170939.GB12431@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent c4ed3f04

arch/x86/mm/memtest.c

+7 −7

Original line number	Diff line number	Diff line
		@@ -40,23 +40,23 @@ static void __init reserve_bad_mem(u64 pattern, u64 start_bad, u64 end_bad)

		static void __init memtest(u64 pattern, u64 start_phys, u64 size)
		{
		u64 i, count;
		u64 *start;
		u64 *p;
		void start, end;
		u64 start_bad, last_bad;
		u64 start_phys_aligned;
		size_t incr;

		incr = sizeof(pattern);
		start_phys_aligned = ALIGN(start_phys, incr);
		count = (size - (start_phys_aligned - start_phys))/incr;
		start = __va(start_phys_aligned);
		end = start + size - (start_phys_aligned - start_phys);
		start_bad = 0;
		last_bad = 0;

		for (i = 0; i < count; i++)
		start[i] = pattern;
		for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
		if (*start == pattern)
		for (p = start; p < end; p++)
		*p = pattern;
		for (p = start; p < end; p++, start_phys_aligned += incr) {
		if (*p == pattern)
		continue;
		if (start_phys_aligned == last_bad + incr) {
		last_bad += incr;

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