From 309381feaee564281c3d9e90fbca8963bb7428ad Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Thu, 23 Jan 2014 15:52:54 -0800 Subject: mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE Most of the VM_BUG_ON assertions are performed on a page. Usually, when one of these assertions fails we'll get a BUG_ON with a call stack and the registers. I've recently noticed based on the requests to add a small piece of code that dumps the page to various VM_BUG_ON sites that the page dump is quite useful to people debugging issues in mm. This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what VM_BUG_ON() does, also dumps the page before executing the actual BUG_ON. [akpm@linux-foundation.org: fix up includes] Signed-off-by: Sasha Levin Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmdebug.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux/mmdebug.h') diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h index 580bd587d916..5042c036dda9 100644 --- a/include/linux/mmdebug.h +++ b/include/linux/mmdebug.h @@ -1,10 +1,19 @@ #ifndef LINUX_MM_DEBUG_H #define LINUX_MM_DEBUG_H 1 +struct page; + +extern void dump_page(struct page *page, char *reason); +extern void dump_page_badflags(struct page *page, char *reason, + unsigned long badflags); + #ifdef CONFIG_DEBUG_VM #define VM_BUG_ON(cond) BUG_ON(cond) +#define VM_BUG_ON_PAGE(cond, page) \ + do { if (unlikely(cond)) { dump_page(page, NULL); BUG(); } } while (0) #else #define VM_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond) +#define VM_BUG_ON_PAGE(cond, page) VM_BUG_ON(cond) #endif #ifdef CONFIG_DEBUG_VIRTUAL -- cgit v1.2.3