Hurd: compliance fixes for getlogin_r

- make LOGIN non-static, as it would make getlogin_r no more reentrant; change its type to string_t
- fail with ERANGE if NAME has not enough space for the actual login string
- copy with memcpy only the chars of the string

2 files changed, 13 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 560bb95533..f50bf6f27f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -13,6 +13,10 @@
 	* sysdeps/mach/hurd/getgroups.c: Return -1 and set EINVAL for
 	negative N or less than NGIDS.
 
+	* sysdeps/mach/hurd/getlogin_r.c: Make LOGIN non-static and change its
+	type to string_t.  Set ERANGE as errno and return it if NAME is not big
+	enough.  Use memcpy instead of strncpy.
+
 2012-07-20  Joseph Myers  <joseph@codesourcery.com>
 
 	* elf/Makefile (check-data): Remove.
diff --git a/sysdeps/mach/hurd/getlogin_r.c b/sysdeps/mach/hurd/getlogin_r.c
index 2539e6b0a0..5410709e71 100644
--- a/sysdeps/mach/hurd/getlogin_r.c
+++ b/sysdeps/mach/hurd/getlogin_r.c
@@ -29,13 +29,20 @@ getlogin_r (name, name_len)
      char *name;
      size_t name_len;
 {
-  static char login[1024];	/* XXX */
+  string_t login;
   error_t err;
 
   if (err = __USEPORT (PROC, __proc_getlogin (port, login)))
     return errno = err;
 
-  strncpy (name, login, name_len);
+  size_t len = __strnlen (login, sizeof login - 1) + 1;
+  if (len > name_len)
+    {
+      errno = ERANGE;
+      return errno;
+    }
+
+  memcpy (name, login, len);
   return 0;
 }
 libc_hidden_def (getlogin_r)