1 files changed, 22 insertions, 1 deletions
diff --git a/include/linux/string.h b/include/linux/string.h
index b2f9df7f0761..02894e417565 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -216,6 +216,8 @@ int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
 				       const void *from, size_t available);
 
+int ptr_to_hashval(const void *ptr, unsigned long *hashval_out);
+
 /**
  * strstarts - does @str start with @prefix?
  * @str: string to examine
@@ -227,7 +229,26 @@ static inline bool strstarts(const char *str, const char *prefix)
 }
 
 size_t memweight(const void *ptr, size_t bytes);
-void memzero_explicit(void *s, size_t count);
+
+/**
+ * memzero_explicit - Fill a region of memory (e.g. sensitive
+ *		      keying data) with 0s.
+ * @s: Pointer to the start of the area.
+ * @count: The size of the area.
+ *
+ * Note: usually using memset() is just fine (!), but in cases
+ * where clearing out _local_ data at the end of a scope is
+ * necessary, memzero_explicit() should be used instead in
+ * order to prevent the compiler from optimising away zeroing.
+ *
+ * memzero_explicit() doesn't need an arch-specific version as
+ * it just invokes the one of memset() implicitly.
+ */
+static inline void memzero_explicit(void *s, size_t count)
+{
+	memset(s, 0, count);
+	barrier_data(s);
+}
 
 /**
  * kbasename - return the last part of a pathname.