Fix error handling in Linux getlogin*.

2 files changed, 16 insertions, 13 deletions

diff --git a/sysdeps/unix/sysv/linux/getlogin.c b/sysdeps/unix/sysv/linux/getlogin.c
index 4d15db093d..58e37c4ab4 100644
--- a/sysdeps/unix/sysv/linux/getlogin.c
+++ b/sysdeps/unix/sysv/linux/getlogin.c
@@ -32,8 +32,9 @@
 char *
 getlogin (void)
 {
-  if (__getlogin_r_loginuid (name, sizeof (name)) == 0)
-    return name;
+  int res = __getlogin_r_loginuid (name, sizeof (name));
+  if (res >= 0)
+    return res == 0 ? name : NULL;
 
   return getlogin_fd0 ();
 }
diff --git a/sysdeps/unix/sysv/linux/getlogin_r.c b/sysdeps/unix/sysv/linux/getlogin_r.c
index dad2671e80..5c3de69e88 100644
--- a/sysdeps/unix/sysv/linux/getlogin_r.c
+++ b/sysdeps/unix/sysv/linux/getlogin_r.c
@@ -58,30 +58,31 @@ __getlogin_r_loginuid (name, namesize)
   bool use_malloc = false;
   struct passwd pwd;
   struct passwd *tpwd;
+  int result = 0;
   int res;
 
-  while ((res = __getpwuid_r (uid, &pwd, buf, buflen, &tpwd)) != 0)
+  while ((res = __getpwuid_r (uid, &pwd, buf, buflen, &tpwd)) == ERANGE)
     if (__libc_use_alloca (2 * buflen))
-      extend_alloca (buf, buflen, 2 * buflen);
+      buf = extend_alloca (buf, buflen, 2 * buflen);
     else
       {
 	buflen *= 2;
 	char *newp = realloc (use_malloc ? buf : NULL, buflen);
 	if (newp == NULL)
 	  {
-	  fail:
-	    if (use_malloc)
-	      free (buf);
-	    return 1;
+	    result = ENOMEM;
+	    goto out;
 	  }
 	buf = newp;
 	use_malloc = true;
       }
 
-  if (tpwd == NULL)
-    goto fail;
+  if (res != 0)
+    {
+      result = -1;
+      goto out;
+    }
 
-  int result = 0;
   size_t needed = strlen (pwd.pw_name) + 1;
   if (needed > namesize)
     {
@@ -109,8 +110,9 @@ getlogin_r (name, namesize)
      char *name;
      size_t namesize;
 {
-  if (__getlogin_r_loginuid (name, namesize) == 0)
-    return 0;
+  int res = __getlogin_r_loginuid (name, namesize);
+  if (res >= 0)
+    return res;
 
   return getlogin_r_fd0 (name, namesize);
 }