Linux Virtualization - Apr 2007 - [PATCH 3/5] Make set_wrprotect() value safe

The macro set_wrprotect() should not be defined to have a value.  Make it
a do {} while(0) instead of ({}).
Noticed by Chris Wright.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Patch-subject: Make set_wrprotect() value safe
Index: linux-2.6.13/include/asm-generic/pgtable.h
==================================================================---
linux-2.6.13.orig/include/asm-generic/pgtable.h	2005-08-15 13:54:42.000000000
-0700
+++ linux-2.6.13/include/asm-generic/pgtable.h	2005-08-22 14:21:05.000000000
-0700
@@ -314,11 +314,11 @@ do {									\
 
 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
 #define ptep_set_wrprotect(__mm, __address, __ptep)			\
-({									\
+do {									\
 	pte_t __old_pte = *(__ptep);					\
 	set_pte_at((__mm), (__address), (__ptep),			\
 			pte_wrprotect(__old_pte));			\
-})
+} while (0)
 #endif
 
 #ifndef __HAVE_ARCH_PTE_SAME

* Zachary Amsden (zach@vmware.com) wrote:
> The macro set_wrprotect() should not be defined to have a value.  Make it
> a do {} while(0) instead of ({}).
> Noticed by Chris Wright.
I already fixed that one in the virt-2.6 git tree.

thanks,
-chris