is_vmalloc_addr(): Check if an address is within the vmalloc boundaries

Checking if an address is a vmalloc address is done in a couple of places.
Define a common version in mm.h and replace the other checks.

Again the include structures suck.  The definition of VMALLOC_START and
VMALLOC_END is not available in vmalloc.h since highmem.c cannot be included
there.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a862a96952e0..f28a0338574f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -235,6 +235,14 @@ static inline int get_page_unless_zero(struct page *page)
 struct page *vmalloc_to_page(const void *addr);
 unsigned long vmalloc_to_pfn(const void *addr);
 
+/* Determine if an address is within the vmalloc range */
+static inline int is_vmalloc_addr(const void *x)
+{
+        unsigned long addr = (unsigned long)x;
+
+        return addr >= VMALLOC_START && addr < VMALLOC_END;
+}
+
 static inline struct page *compound_head(struct page *page)
 {
         if (unlikely(PageTail(page)))