Update.

	* sysdeps/unix/sysv/linux/getdents.c (__getdents): The Linux
	kernel does not allow relative seeks on descriptors associated
	with directories.  Go back to get the position in the directory
	every time we enter the function.  Return -1 and set errno if one
	entry could be read from the kernel but does not fit into the
	buffer passed in by the user.

2 files changed, 20 insertions, 9 deletions

diff --git a/ChangeLog b/ChangeLog
index 81a258dfe1..0b8ec99a54 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2000-04-06  Ulrich Drepper  <drepper@redhat.com>
 
+	* sysdeps/unix/sysv/linux/getdents.c (__getdents): The Linux
+	kernel does not allow relative seeks on descriptors associated
+	with directories.  Go back to get the position in the directory
+	every time we enter the function.  Return -1 and set errno if one
+	entry could be read from the kernel but does not fit into the
+	buffer passed in by the user.
+
 	* locale/programs/charmap.c (charmap_new_char): Add parameter step.
 	Support ..(2).. ellipsis.
 	(parse_charmap): Recognize ..(2).. etc and pass step down.
diff --git a/sysdeps/unix/sysv/linux/getdents.c b/sysdeps/unix/sysv/linux/getdents.c
index 9a2255c0da..d142843cbe 100644
--- a/sysdeps/unix/sysv/linux/getdents.c
+++ b/sysdeps/unix/sysv/linux/getdents.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1993, 95, 96, 97, 98, 99 Free Software Foundation, Inc.
+/* Copyright (C) 1993, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -67,7 +67,7 @@ ssize_t
 internal_function
 __getdents (int fd, char *buf, size_t nbytes)
 {
-  off_t last_offset = 0;
+  off_t last_offset = __lseek (fd, 0, SEEK_CUR);
   size_t red_nbytes;
   struct kernel_dirent *skdp, *kdp;
   struct dirent *dp;
@@ -96,13 +96,17 @@ __getdents (int fd, char *buf, size_t nbytes)
       if ((char *) dp + new_reclen > buf + nbytes)
 	{
 	  /* Our heuristic failed.  We read too many entries.  Reset
-	     the stream.  `last_offset' contains the last known
-	     position.  If it is zero this is the first record we are
-	     reading.  In this case do a relative search.  */
-	  if (last_offset == 0)
-	    __lseek (fd, -retval, SEEK_CUR);
-	  else
-	    __lseek (fd, last_offset, SEEK_SET);
+	     the stream.  */
+	  __lseek (fd, last_offset, SEEK_SET);
+
+	  if ((char *) dp == buf)
+	    {
+	      /* The buffer the user passed in is too small to hold even
+		 one entry.  */
+	      __set_errno (EINVAL);
+	      return -1;
+	    }
+
 	  break;
 	}