slab: introduce krealloc

[~andy/linux] / mm / slob.c

diff --git a/mm/slob.c b/mm/slob.c
index 5adc29cb58dd5768044380b414f5818158a5b2be..03cce3d3d986346106e725c3848ec7505fe7d847 100644 (file)
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -190,6 +190,39 @@ void *__kmalloc(size_t size, gfp_t gfp)
 }
 EXPORT_SYMBOL(__kmalloc);
 
+/**
+ * krealloc - reallocate memory. The contents will remain unchanged.
+ *
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * The contents of the object pointed to are preserved up to the
+ * lesser of the new and old sizes.  If @p is %NULL, krealloc()
+ * behaves exactly like kmalloc().  If @size is 0 and @p is not a
+ * %NULL pointer, the object pointed to is freed.
+ */
+void *krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+       void *ret;
+
+       if (unlikely(!p))
+               return kmalloc_track_caller(new_size, flags);
+
+       if (unlikely(!new_size)) {
+               kfree(p);
+               return NULL;
+       }
+
+       ret = kmalloc_track_caller(new_size, flags);
+       if (ret) {
+               memcpy(ret, p, min(new_size, ksize(p)));
+               kfree(p);
+       }
+       return ret;
+}
+EXPORT_SYMBOL(krealloc);
+
 void kfree(const void *block)
 {
        bigblock_t *bb, **last = &bigblocks;
@@ -219,7 +252,7 @@ void kfree(const void *block)
 
 EXPORT_SYMBOL(kfree);
 
-unsigned int ksize(const void *block)
+size_t ksize(const void *block)
 {
        bigblock_t *bb;
        unsigned long flags;