VIRTUAL_BUG_ON()

[Christoph Lameter <clameter@sgi.com>]

On Sat, 26 Apr 2008, Andi Kleen wrote:

> > Good idea! Do you have a patch?
> 
> Yes. Appended. But it just enables the old NUMA VIRTUAL_BUG_ON()s, more 
> work could be done e.g. by instrumenting pa/va and the non NUMA and i386 
> case too.

Hmmmm.. No hooks yet? I have some pieces here that do something similar:

Subject: Add checks for virtual addresses

Add checks to insure that virtual addresses are not used in invalid contexts.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

---
 arch/x86/mm/ioremap.c     |    1 +
 include/asm-x86/page_32.h |    7 ++++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

Index: linux-2.6.25-mm1/arch/x86/mm/ioremap.c
===================================================================
--- linux-2.6.25-mm1.orig/arch/x86/mm/ioremap.c	2008-04-25 23:17:31.872390404 -0700
+++ linux-2.6.25-mm1/arch/x86/mm/ioremap.c	2008-04-25 23:37:43.202391820 -0700
@@ -25,6 +25,7 @@
 
 unsigned long __phys_addr(unsigned long x)
 {
+	VM_BUG_ON(is_vmalloc_addr((void *)x));
 	if (x >= __START_KERNEL_map)
 		return x - __START_KERNEL_map + phys_base;
 	return x - PAGE_OFFSET;
Index: linux-2.6.25-mm1/include/asm-x86/page_32.h
===================================================================
--- linux-2.6.25-mm1.orig/include/asm-x86/page_32.h	2008-04-25 23:17:31.882389317 -0700
+++ linux-2.6.25-mm1/include/asm-x86/page_32.h	2008-04-25 23:37:43.202391820 -0700
@@ -64,7 +64,12 @@ typedef struct page *pgtable_t;
 #endif
 
 #ifndef __ASSEMBLY__
-#define __phys_addr(x)		((x) - PAGE_OFFSET)
+static inline unsigned long __phys_addr(unsigned long x)
+{
+	VM_BUG_ON(is_vmalloc_addr((void *)x));
+	return x - PAGE_OFFSET;
+}
+
 #define __phys_reloc_hide(x)	RELOC_HIDE((x), 0)
 
 #ifdef CONFIG_FLATMEM