1 files changed, 50 insertions, 3 deletions

diff --git a/include/linux/string.h b/include/linux/string.h
index 47a27a391f..0d046f7832 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -1,8 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
 #ifndef _LINUX_STRING_H_
 #define _LINUX_STRING_H_
 
 #include <linux/types.h>	/* for size_t */
 #include <linux/stddef.h>	/* for NULL */
+#include <linux/overflow.h>	/* for array_size */
 
 #ifdef __cplusplus
 extern "C" {
@@ -43,6 +46,9 @@ extern char * strncpy(char *,const char *, __kernel_size_t);
 #ifndef __HAVE_ARCH_STRLCPY
 size_t strlcpy(char *, const char *, size_t);
 #endif
+#ifndef __HAVE_ARCH_STRSCPY
+ssize_t strscpy(char *, const char *, size_t);
+#endif
 #ifndef __HAVE_ARCH_STRCAT
 extern char * strcat(char *, const char *);
 #endif
@@ -55,9 +61,6 @@ extern int strcmp(const char *,const char *);
 #ifndef __HAVE_ARCH_STRNCMP
 extern int strncmp(const char *,const char *,__kernel_size_t);
 #endif
-#ifndef __HAVE_ARCH_STRNICMP
-extern int strnicmp(const char *, const char *, __kernel_size_t);
-#endif
 #ifndef __HAVE_ARCH_STRCASECMP
 extern int strcasecmp(const char *s1, const char *s2);
 #endif
@@ -112,6 +115,27 @@ extern char * skip_spaces(const char *);
 extern char *strim(char *);
 
 void *memchr_inv(const void *start, int c, size_t bytes);
+char *strreplace(char *str, char old, char new);
+
+/**
+ * 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.
@@ -131,6 +155,8 @@ static inline const char *kbasename(const char *path)
 
 void *memdup(const void *, size_t);
 
+#define memdup_array(arr, count) memdup(arr, array_size(count, sizeof(*arr)));
+
 static inline void *kmemdup(const void *src, size_t len, gfp_t gfp)
 {
 	return memdup(src, len);
@@ -150,4 +176,25 @@ static inline bool strstarts(const char *str, const char *prefix)
 	return strncmp(str, prefix, strlen(prefix)) == 0;
 }
 
+/**
+ * str_has_prefix - Test if a string has a given prefix
+ * @str: The string to test
+ * @prefix: The string to see if @str starts with
+ *
+ * A common way to test a prefix of a string is to do:
+ *  strncmp(str, prefix, sizeof(prefix) - 1)
+ *
+ * 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:
+ * * 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)
+{
+	size_t len = strlen(prefix);
+	return strncmp(str, prefix, len) == 0 ? len : 0;
+}
+
 #endif /* _LINUX_STRING_H_ */