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mm/hwpoison: fix traversal of hugetlbfs pages to avoid printk flood 

madvise_hwpoison won't check if the page is small page or huge page and
traverses in small page granularity against the range unconditionally,
which result in a printk flood "MCE xxx: already hardware poisoned" if
the page is a huge page.

This patch fixes it by using compound_order(compound_head(page)) for
huge page iterator.

Testcase:

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>

#define PAGES_TO_TEST 3
#define PAGE_SIZE	4096 * 512

int main(void)
{
	char *mem;
	int i;

	mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
			PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, 0, 0);

	if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
		return -1;

	munmap(mem, PAGES_TO_TEST * PAGE_SIZE);

	return 0;
}

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
wifi-calibration
Wanpeng Li 2013-09-30 13:45:21 -07:00 committed by Linus Torvalds
parent 080506ad0a
commit 20cb6cab52
1 changed files with 3 additions and 2 deletions
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5
mm/madvise.c
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@ -343,10 +343,11 @@ static long madvise_remove(struct vm_area_struct *vma,
*/
static int madvise_hwpoison(int bhv, unsigned long start, unsigned long end)
{
struct page *p;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
for (; start < end; start += PAGE_SIZE) {
struct page *p;
for (; start < end; start += PAGE_SIZE <<
compound_order(compound_head(p))) {
int ret;
ret = get_user_pages_fast(start, 1, 0, &p);