From: Rik van Riel <riel@redhat.com>

Use generic_access_phys as the access_process_vm access function for
/dev/mem mappings.  This makes it possible to debug the X server.

Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Benjamin Herrensmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/char/mem.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff -puN drivers/char/mem.c~use-generic_access_phys-for-dev-mem-mappings drivers/char/mem.c
--- a/drivers/char/mem.c~use-generic_access_phys-for-dev-mem-mappings
+++ a/drivers/char/mem.c
@@ -327,7 +327,8 @@ static void mmap_mem_close(struct vm_are
 
 static struct vm_operations_struct mmap_mem_ops = {
 	.open  = mmap_mem_open,
-	.close = mmap_mem_close
+	.close = mmap_mem_close,
+	.access = generic_access_phys
 };
 
 static int mmap_mem(struct file * file, struct vm_area_struct * vma)
_