Avoid false positive warnings in kmap_atomic_prot() with DEBUG_HIGHMEM
I believe http://bugzilla.kernel.org/show_bug.cgi?id=10318 is a false
positive. There's no way in which networking will be using highmem pages
here, so it won't be taking the KM_USER0 kmap slot, so there's no point in
performing these checks.
Cc: Pawel Staszewski <pstaszewski@artcom.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Really sad. We lose almost all real-life coverage of the debug tests
with this patch. Now it will only report problems for the cases where
people actually end up using a HIGHMEM page, not when they just _might_
use one. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 3d936f2..9cf33d3 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -73,15 +73,15 @@
{
enum fixed_addresses idx;
unsigned long vaddr;
+
/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
-
- debug_kmap_atomic_prot(type);
-
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
+ debug_kmap_atomic_prot(type);
+
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
BUG_ON(!pte_none(*(kmap_pte-idx)));