From 0208fabf7256245125fbabf03207a0da4000ea2d Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 24 Nov 2017 11:13:07 +0100 Subject: mm, hwpoison: fixup "mm: check the return value of lookup_page_ext for all call sites" Backport of the upstream commit f86e4271978b ("mm: check the return value of lookup_page_ext for all call sites") is wrong for hwpoison pages. I have accidentally negated the condition for bailout. This basically disables hwpoison pages tracking while the code still might crash on unusual configurations when struct pages do not have page_ext allocated. The fix is trivial to invert the condition. Reported-by: Jiri Slaby Signed-off-by: Michal Hocko Signed-off-by: Greg Kroah-Hartman --- mm/debug-pagealloc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c index fe1c61f7cf26..3b8f1b83610e 100644 --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -34,7 +34,7 @@ static inline void set_page_poison(struct page *page) struct page_ext *page_ext; page_ext = lookup_page_ext(page); - if (page_ext) + if (!page_ext) return; __set_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags); } @@ -44,7 +44,7 @@ static inline void clear_page_poison(struct page *page) struct page_ext *page_ext; page_ext = lookup_page_ext(page); - if (page_ext) + if (!page_ext) return; __clear_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags); } @@ -54,7 +54,7 @@ static inline bool page_poison(struct page *page) struct page_ext *page_ext; page_ext = lookup_page_ext(page); - if (page_ext) + if (!page_ext) return false; return test_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags); } -- cgit v1.2.3