From d15f107d97bd74c74d8f5144843d372666ddbdac Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 16 Dec 2009 12:20:00 +0100 Subject: [PATCH] HWPOISON: Use get_user_page_fast in hwpoison madvise The previous version didn't take the mmap_sem before calling gup(), which is racy. Use get_user_pages_fast() instead which doesn't need any locks. This is also faster of course, but then it doesn't really matter because this is just a testing path. Based on report from Nick Piggin. Cc: npiggin@suse.de Signed-off-by: Andi Kleen --- mm/madvise.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 6ca34f0cd4aa..7964e36ba915 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -230,8 +230,7 @@ static int madvise_hwpoison(unsigned long start, unsigned long end) return -EPERM; for (; start < end; start += PAGE_SIZE) { struct page *p; - int ret = get_user_pages(current, current->mm, start, 1, - 0, 0, &p, NULL); + int ret = get_user_pages_fast(start, 1, 0, &p); if (ret != 1) return ret; printk(KERN_INFO "Injecting memory failure for page %lx at %lx\n", -- 2.20.1