From f9092f358bc2ec5367621478811f046f82873376 Mon Sep 17 00:00:00 2001 From: Jonathan Steel Date: Mon, 22 Sep 2008 13:57:45 -0700 Subject: kexec: fix segmentation fault in kimage_add_entry A segmentation fault can occur in kimage_add_entry in kexec.c when loading a kernel image into memory. The fault occurs because a page is requested by calling kimage_alloc_page with gfp_mask GFP_KERNEL and the function may actually return a page with gfp_mask GFP_HIGHUSER. The high mem page is returned because it was swapped with the kernel page due to the kernel page being a page that will shortly be copied to. This patch ensures that kimage_alloc_page returns a page that was created with the correct gfp flags. I have verified the change and fixed the whitespace damage of the original patch. Jonathan did a great job of tracking this down after he hit the problem. -- Eric Signed-off-by: Jonathan Steel Signed-off-by: Eric W. Biederman Acked-by: Simon Horman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kexec.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'kernel/kexec.c') diff --git a/kernel/kexec.c b/kernel/kexec.c index 59f3f0df35d4..aef265325cd3 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -753,8 +753,14 @@ static struct page *kimage_alloc_page(struct kimage *image, *old = addr | (*old & ~PAGE_MASK); /* The old page I have found cannot be a - * destination page, so return it. + * destination page, so return it if it's + * gfp_flags honor the ones passed in. */ + if (!(gfp_mask & __GFP_HIGHMEM) && + PageHighMem(old_page)) { + kimage_free_pages(old_page); + continue; + } addr = old_addr; page = old_page; break; -- cgit v1.2.3