I recently got the order of arguments to VM_BUG_ON_VMA the wrong way
around, which was only noticable when compiling with CONFIG_DEBUG_VM.
Prevent the next mistake of this kind by making the macros evaluate both
their arguments at compile time (this has no effect on the built kernel).
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@xxxxxxxxx>
---
include/linux/mmdebug.h | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h
index de7be78..abfc316 100644
--- a/include/linux/mmdebug.h
+++ b/include/linux/mmdebug.h
@@ -41,9 +41,24 @@ void dump_mm(const struct mm_struct *mm);
#define VM_WARN_ONCE(cond, format...) WARN_ONCE(cond, format)
#else
#define VM_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond)
-#define VM_BUG_ON_PAGE(cond, page) VM_BUG_ON(cond)
-#define VM_BUG_ON_VMA(cond, vma) VM_BUG_ON(cond)
-#define VM_BUG_ON_MM(cond, mm) VM_BUG_ON(cond)
+#define VM_BUG_ON_PAGE(cond, page) \
+ do { \
+ if (0) dump_page(page, ""); \
+ VM_BUG_ON(cond); \
+ } while (0)
+
+#define VM_BUG_ON_VMA(cond, vma) \
+ do { \
+ if (0) dump_vma(vma); \
+ VM_BUG_ON(cond); \
+ } while (0)
+
+#define VM_BUG_ON_MM(cond, mm) \
+ do { \
+ if (0) dump_mm(mm); \
+ VM_BUG_ON(cond); \
+ } while (0)
+
#define VM_WARN_ON(cond) BUILD_BUG_ON_INVALID(cond)
#define VM_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond)
#define VM_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond)
--
2.7.0
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>