From 20cb6cab52a21b46e3c0dc7bd23f004f810fb421 Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Mon, 30 Sep 2013 13:45:21 -0700 Subject: [PATCH] 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 #include #include #include #include #include #include #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 Reviewed-by: Naoya Horiguchi Acked-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/madvise.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 6975bc812542..539eeb96b323 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -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); -- 2.20.1