update from main archive 970127cvs/libc-970128

1997-01-28 04:23  Ulrich Drepper  <drepper@cygnus.com>
	* version.h (VERSION): Bump to 2.0.1.
	* posix/getopt.c: Handle another problem introduced by the
	nonoption_flags array.  We must be able to work with reordered
	argv arrays.  Reported by Andreas Schwab.
1997-01-28 02:38  Ulrich Drepper  <drepper@cygnus.com>
	* sysdeps/unix/sysv/linux/i386/clone.S: Correct handling of new
1997-01-27 17:34  Thorsten Kukuk <kukuk@weber.uni-paderborn.de>
	* nis/rpcsvc/yp_prot.h: Correct definitions and types in file so
	that it works with yp.h.
1997-01-27 13:28  Ulrich Drepper  <drepper@cygnus.com>
	* malloc/malloc.h (__malloc_initialized) [_LIBC]: Define as
	__libc_malloc_initialized so that this variable is not shared with
	other users of GNU malloc.
	Suggested by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>.
	* mcheck.h: Correct typo.  Use malloc/ instead of new-malloc/.
	* sysdeps/i386/Makefile (CFLAGS-dl-load.c, CFLAGS-dl-reloc.c): New
	variables to prevent warnings.
	* sysdeps/i386/dl-machine.h (fixup): Add prototype and declare
	using attribute regparm.
	(ELF_MACHINE_RUNTIME_TRAMPOLINE): Rewrite so that no register
	is changed by the resolver code.
1997-01-14 14:20  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
	* malloc/malloc.c (weak_variable): Define.
	(__malloc_initialize_hook, __free_hook, __malloc_hook, __realloc_hook,
	__memalign_hook): Make them weak definitions.
1997-01-26 11:35  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
	* sysdeps/unix/sysv/linux/getdents.c: Don't write beyond buffer
	limits, correctly take structure padding into account, use correct
	offset when resetting the stream, change heuristic to assume an
	average name length of 14 characters.
1997-01-25 18:06  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
	* sysdeps/unix/sysv/linux/alpha/termbits.h: Protect against multiple
	inclusion.
See ChangeLog.6 for earlier changes.

1 files changed, 26 insertions, 19 deletions

diff --git a/sysdeps/unix/sysv/linux/getdents.c b/sysdeps/unix/sysv/linux/getdents.c
index 40b31617ef..b4b12d48eb 100644
--- a/sysdeps/unix/sysv/linux/getdents.c
+++ b/sysdeps/unix/sysv/linux/getdents.c
@@ -49,11 +49,11 @@ struct kernel_dirent
 
 /* The problem here is that we cannot simply read the next NBYTES
    bytes.  We need to take the additional field into account.  We use
-   some heuristic.  Assume the directory contains names with at least
-   3 characters we can compute a maximum number of entries which fit
-   in the buffer.  Taking this number allows us to specify a correct
-   number of bytes to read.  If we should be wrong, we can reset the
-   file descriptor.  */
+   some heuristic.  Assuming the directory contains names with 14
+   characters on average we can compute an estimate number of entries
+   which fit in the buffer.  Taking this number allows us to specify a
+   correct number of bytes to read.  If we should be wrong, we can reset
+   the file descriptor.  */
 ssize_t
 __getdirentries (fd, buf, nbytes, basep)
      int fd;
@@ -62,12 +62,16 @@ __getdirentries (fd, buf, nbytes, basep)
      off_t *basep;
 {
   off_t base = __lseek (fd, (off_t) 0, SEEK_CUR);
+  off_t last_offset = base;
   size_t red_nbytes;
   struct kernel_dirent *skdp, *kdp;
   struct dirent *dp;
   int retval;
+  const size_t size_diff = (offsetof (struct dirent, d_name)
+			    - offsetof (struct kernel_dirent, d_name));
 
-  red_nbytes = nbytes - (nbytes / (offsetof (struct dirent, d_name) + 3));
+  red_nbytes = nbytes - ((nbytes / (offsetof (struct dirent, d_name) + 14))
+			 * size_diff);
 
   dp = (struct dirent *) buf;
   skdp = kdp = __alloca (red_nbytes);
@@ -76,26 +80,29 @@ __getdirentries (fd, buf, nbytes, basep)
 
   while ((char *) kdp < (char *) skdp + retval)
     {
-      const size_t size_diff = MAX (offsetof (struct dirent, d_name)
-				    - offsetof (struct kernel_dirent, d_name),
-				    __alignof__ (struct dirent));
+      const size_t alignment = __alignof__ (struct dirent);
+      /* Since kdp->d_reclen is already aligned for the kernel structure
+	 this may compute a value that is bigger than necessary.  */
+      size_t new_reclen = ((kdp->d_reclen + size_diff + alignment - 1)
+			   & ~(alignment - 1));
+      if ((char *) dp + new_reclen > buf + nbytes)
+	{
+	  /* Our heuristic failed.  We read too many entries.  Reset
+	     the stream.  */
+	  __lseek (fd, last_offset, SEEK_SET);
+	  break;
+	}
+
+      last_offset = kdp->d_off;
       dp->d_ino = kdp->d_ino;
       dp->d_off = kdp->d_off;
-      dp->d_reclen = kdp->d_reclen + size_diff;
+      dp->d_reclen = new_reclen;
       dp->d_type = DT_UNKNOWN;
       memcpy (dp->d_name, kdp->d_name,
 	      kdp->d_reclen - offsetof (struct kernel_dirent, d_name));
 
-      dp = (struct dirent *) (((char *) dp) + dp->d_reclen);
+      dp = (struct dirent *) ((char *) dp + new_reclen);
       kdp = (struct kernel_dirent *) (((char *) kdp) + kdp->d_reclen);
-
-      if ((char *) dp >= buf + nbytes)
-	{
-	  /* Our heuristic failed.  We read too many entries.  Reset
-	     the stream.  */
-	  off_t used = ((char *) kdp - (char *) buf) - (nbytes - red_nbytes);
-	  base = __lseek (fd, retval - used, SEEK_CUR);
-	}
     }
 
   if (basep)