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-rw-r--r--include/linux/string.h29
1 files changed, 26 insertions, 3 deletions
diff --git a/include/linux/string.h b/include/linux/string.h
index 4deb11f7976b..6dfbb2efa815 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -62,6 +62,7 @@ extern char * strchr(const char *,int);
#ifndef __HAVE_ARCH_STRCHRNUL
extern char * strchrnul(const char *,int);
#endif
+extern char * strnchrnul(const char *, size_t, int);
#ifndef __HAVE_ARCH_STRNCHR
extern char * strnchr(const char *, size_t, int);
#endif
@@ -216,6 +217,8 @@ 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 +230,26 @@ 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.
@@ -474,8 +496,9 @@ static inline void memcpy_and_pad(void *dest, size_t dest_len,
* But this can lead to bugs due to typos, or if prefix is a pointer
* and not a constant. Instead use str_has_prefix().
*
- * Returns: 0 if @str does not start with @prefix
- strlen(@prefix) if @str does start with @prefix
+ * Returns:
+ * * strlen(@prefix) if @str starts with @prefix
+ * * 0 if @str does not start with @prefix
*/
static __always_inline size_t str_has_prefix(const char *str, const char *prefix)
{
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