[PATCH] strndup_user()

This patch series creates a strndup_user() function to easy copying C strings
from userspace.  Also we avoid common pitfalls like userspace modifying the
final \0 after the strlen_user().

Signed-off-by: Davi Arnaut <davi.arnaut@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/string.h b/include/linux/string.h
index 369be3264a55..dee221429ad0 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -18,6 +18,8 @@ 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 *strndup_user(const char __user *, long);
+
 /*
  * Include machine specific inline routines
  */