datapath: Don't pass __GFP_ZERO to kmalloc on older kernels.

On new kernels kzalloc() is simply a wrapper around kmalloc with
the addition of the __GFP_ZERO flag.  flex_arrays take advantage
of this by expecting the user to just pass in this flag if they
want the memory to be zeroed.  However, before 2.6.23, kzalloc()
was a function in its own right and kmalloc really didn't like
receiving __GFP_ZERO.  This overrides kmalloc() to intercept the
flags and direct the call to the right function.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

diff --git a/datapath/linux/compat/include/linux/slab.h b/datapath/linux/compat/include/linux/slab.h
index 7e9c3f4..9d6ad1f 100644 (file)
--- a/datapath/linux/compat/include/linux/slab.h
+++ b/datapath/linux/compat/include/linux/slab.h
@@ -11,4 +11,21 @@ extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
 #define kmem_cache_create(n, s, a, f, c) kmem_cache_create(n, s, a, f, c, NULL)
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
+static inline void *rpl_kzalloc(size_t size, gfp_t flags)
+{
+       return kzalloc(size, flags & ~__GFP_ZERO);
+}
+#define kzalloc rpl_kzalloc
+
+static inline void *rpl_kmalloc(size_t size, gfp_t flags)
+{
+       if (flags & __GFP_ZERO)
+               return kzalloc(size, flags);
+
+       return kmalloc(size, flags);
+}
+#define kmalloc rpl_kmalloc
+#endif
+
 #endif