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authorSasha Levin <sasha.levin@oracle.com>2014-01-23 15:52:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-23 16:36:50 -0800
commit309381feaee564281c3d9e90fbca8963bb7428ad (patch)
tree7e9f990c0cffcb8c5fc90deb1c7eac445c5ada0e /include/linux/mmdebug.h
parente3bba3c3c90cd434c1ccb9e5dc704a96baf9541c (diff)
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 <sasha.levin@oracle.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mmdebug.h')
-rw-r--r--include/linux/mmdebug.h9
1 files changed, 9 insertions, 0 deletions
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