The world continually reimplements kstrdup().  Implement an optimal version
and export it to the world.

By: Robert Love and Rusty Russell.

Signed-off-by: Robert Love <rml@novell.com>

 include/linux/string.h |    1 +
 lib/string.c           |   20 ++++++++++++++++++++
 2 files changed, 21 insertions(+)

diff -urN linux-2.6.12-rc3/include/linux/string.h linux/include/linux/string.h
--- linux-2.6.12-rc3/include/linux/string.h	2005-03-02 02:38:07.000000000 -0500
+++ linux/include/linux/string.h	2005-04-21 21:23:04.000000000 -0400
@@ -17,6 +17,7 @@
 extern char * strsep(char **,const char *);
 extern __kernel_size_t strspn(const char *,const char *);
 extern __kernel_size_t strcspn(const char *,const char *);
+extern char * kstrdup(const char *,unsigned int __nocast);
 
 /*
  * Include machine specific inline routines
diff -urN linux-2.6.12-rc3/lib/string.c linux/lib/string.c
--- linux-2.6.12-rc3/lib/string.c	2005-03-02 02:38:25.000000000 -0500
+++ linux/lib/string.c	2005-04-21 21:31:11.000000000 -0400
@@ -22,6 +22,7 @@
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/ctype.h>
+#include <linux/slab.h>
 #include <linux/module.h>
 
 #ifndef __HAVE_ARCH_STRNICMP
@@ -76,6 +77,25 @@
 EXPORT_SYMBOL(strcpy);
 #endif
 
+/*
+ * kstrdup - allocate space for and then copy an existing string
+ *
+ * @str: the string to duplicate
+ * @gfp: the GFP mask used to allocate the storage for the duplicated string
+ */
+char * kstrdup(const char *str, unsigned int __nocast flags)
+{
+	size_t len;
+	char *buf;
+
+	len = strlen(str) + 1;
+	buf = kmalloc(len, flags);
+	if (likely(buf))
+		memcpy(buf, str, len);
+	return buf;
+}
+EXPORT_SYMBOL(kstrdup);
+
 #ifndef __HAVE_ARCH_STRNCPY
 /**
  * strncpy - Copy a length-limited, %NUL-terminated string