Update.

	* csu/Makefile (routines): Add check_fds.
	* elf/rtld.c (dl_main): Call __libc_check_standard_fds for SUID
	binaries.  Add various __builtin_expect.
	* sysdeps/generic/libc-start.c: Move check_fds and helper functions...
	* sysdeps/generic/check_fds.c: ...here.  New file.

	* malloc/malloc.c (ptmalloc_init): Only enable debugging for SUID
	binaries if file /etc/suid-debug is available.

2 files changed, 69 insertions, 36 deletions

diff --git a/sysdeps/generic/check_fds.c b/sysdeps/generic/check_fds.c
new file mode 100644
index 0000000..4eea168
--- /dev/null
+++ b/sysdeps/generic/check_fds.c
@@ -0,0 +1,62 @@
+/* Copyright (C) 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
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <paths.h>
+#include <unistd.h>
+
+/* Try to get a machine dependent instruction which will make the
+   program crash.  This is used in case everything else fails.  */
+#include <abort-instr.h>
+#ifndef ABORT_INSTRUCTION
+/* No such instruction is available.  */
+# define ABORT_INSTRUCTION
+#endif
+
+
+/* Should other OSes (e.g., Hurd) have different versions which can
+   be written in a better way?  */
+static void
+check_one_fd (int fd, int mode)
+{
+  if (__builtin_expect (__libc_fcntl (fd, F_GETFD), 0) == -1
+      && errno == EBADF)
+    {
+      /* Something is wrong with this descriptor, it's probably not
+	 opened.  Open /dev/null so that the SUID program we are
+	 about to start does not accidently use this descriptor.  */
+      int nullfd = __libc_open (_PATH_DEVNULL, mode);
+      if (__builtin_expect (nullfd, 0) == -1)
+	/* We cannot even give an error message here since it would
+	   run into the same problems.  */
+	while (1)
+	  /* Try for ever and ever.  */
+	  ABORT_INSTRUCTION;
+    }
+}
+
+
+void
+__libc_check_standard_fds (void)
+{
+/* Check all three standard file descriptors.  */
+  check_one_fd (STDIN_FILENO, O_RDONLY);
+  check_one_fd (STDOUT_FILENO, O_RDWR);
+  check_one_fd (STDERR_FILENO, O_RDWR);
+}
diff --git a/sysdeps/generic/libc-start.c b/sysdeps/generic/libc-start.c
index fe4966c..f5486f9 100644
--- a/sysdeps/generic/libc-start.c
+++ b/sysdeps/generic/libc-start.c
@@ -16,12 +16,8 @@
    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.  */
 
-#include <errno.h>
-#include <fcntl.h>
-#include <paths.h>
 #include <stdlib.h>
 #include <unistd.h>
-#include <sys/ioctl.h>
 #include <ldsodefs.h>
 
 extern void __libc_init_first (int argc, char **argv, char **envp);
@@ -32,7 +28,7 @@ extern int __libc_multiple_libcs;
 extern void *__libc_stack_end;
 
 /* Prototype for local function.  */
-static void check_standard_fds (void);
+extern void __libc_check_standard_fds (void);
 
 int
 __libc_start_main (int (*main) (int, char **, char **), int argc,
@@ -54,10 +50,14 @@ __libc_start_main (int (*main) (int, char **, char **), int argc,
   /* Set the global _environ variable correctly.  */
   __environ = &argv[argc + 1];
 
+#ifndef SHARED
   /* Some security at this point.  Prevent starting a SUID binary where
-     the standard file descriptors are not opened.  */
+     the standard file descriptors are not opened.  We have to do this
+     only for statically linked applications since otherwise the dynamic
+     loader did the work already.  */
   if (__builtin_expect (__libc_enable_secure, 0))
-    check_standard_fds ();
+    __libc_check_standard_fds ();
+#endif
 
   /* Register the destructor of the dynamic linker if there is any.  */
   if (__builtin_expect (rtld_fini != NULL, 1))
@@ -89,32 +89,3 @@ __libc_start_main (int (*main) (int, char **, char **), int argc,
 
   exit ((*main) (argc, argv, __environ));
 }
-
-
-/* Should other OSes (e.g., Hurd) have different versions which can
-   be written in a better way?  */
-static void
-check_one_fd (int fd, int mode)
-{
-  if (__libc_fcntl (fd, F_GETFD) == -1 && errno == EBADF)
-    {
-      /* Something is wrong with this descriptor, it's probably not
-	 opened.  Open /dev/null so that the SUID program we are
-	 about to start does not accidently use this descriptor.  */
-      int nullfd = __libc_open (_PATH_DEVNULL, mode);
-      if (nullfd == -1)
-	/* We cannot even give an error message here since it would
-	   run into the same problems.  */
-	abort ();
-    }
-}
-
-
-static void
-check_standard_fds (void)
-{
-/* Check all three standard file descriptors.  */
-  check_one_fd (STDIN_FILENO, O_RDONLY);
-  check_one_fd (STDOUT_FILENO, O_RDWR);
-  check_one_fd (STDERR_FILENO, O_RDWR);
-}