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Subject[PATCH] kunmap_atomic debugging problem
[resend from a few months ago ;)]

I found a bug in the HIGHMEM_DEBUG code, in kunmap_atomic()
to be specific. The problem is that kunmap_atomic() can get
called with an address which isn't page aligned, but we compare
that address to a page aligned address and bug if the two
aren't equal.

The obvious fix is to page-align the address before doing the
check, we're not doing anything else with it anyway since
kunmap_atomic() is a nop if HIGHMEM_DEBUG is off.


--- linux-2.4.20/include/asm-i386/highmem.h.debug 2003-04-14 17:46:28.000000000 -0400
+++ linux-2.4.20/include/asm-i386/highmem.h 2003-04-14 17:46:43.000000000 -0400
@@ -109,7 +109,7 @@ static inline void *kmap_atomic(struct p
static inline void kunmap_atomic(void *kvaddr, enum km_type type)
{
#if HIGHMEM_DEBUG
- unsigned long vaddr = (unsigned long) kvaddr;
+ unsigned long vaddr = (unsigned long) kvaddr & PAGE_ADDRESS;
enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();

if (vaddr < FIXADDR_START) // FIXME
-
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