[PATCH bpf-next 4/7] mm: util: introduce kvsize()

[Yafang Shao <laoar.shao@xxxxxxxxx>]

Introduce a new help kvsize() to report full size of underlying allocation
of a kmalloc'ed addr or vmalloc'ed addr.

Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
---
 include/linux/slab.h |  1 +
 mm/util.c            | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 45af703..cccb4d8 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -762,6 +762,7 @@ static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t fla
 
 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
 		      __realloc_size(3);
+extern size_t kvsize(void *addr);
 extern void kvfree(const void *addr);
 extern void kvfree_sensitive(const void *addr, size_t len);
 
diff --git a/mm/util.c b/mm/util.c
index b56c92f..f77d0cc 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -610,6 +610,21 @@ void *kvmalloc_node(size_t size, gfp_t flags, int node)
 EXPORT_SYMBOL(kvmalloc_node);
 
 /**
+ * kvsize() - Report full size of underlying allocation of adddr
+ * @addr: Pointer to kmalloc'ed or vmalloc'ed memory
+ *
+ * kvsize reports full size of underlying allocation of a kmalloc'ed addr
+ * or a vmalloc'ed addr.
+ */
+size_t kvsize(void *addr)
+{
+	if (is_vmalloc_addr(addr))
+		return vsize(addr);
+
+	return ksize(addr);
+}
+
+/**
  * kvfree() - Free memory.
  * @addr: Pointer to allocated memory.
  *
-- 
1.8.3.1