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2000-06-07 Greg McGary <greg@mcgary.org>
* sysdeps/generic/bp-sym.h: New file.
* sysdeps/generic/bp-start.h: New file.
* sysdeps/i386/elf/start.S: Designate BP symbols.
* sysdeps/generic/libc-start.c: Wrap bounds around
argv & envp and each of their string members.
Index: sysdeps/generic/bp-sym.h
===================================================================
RCS file: bp-sym.h
diff -N bp-sym.h
--- /dev/null Tue May 5 13:32:27 1998
+++ bp-sym.h Wed Jun 7 17:17:35 2000
@@ -0,0 +1,28 @@
+/* Bounded-pointer symbol modifier.
+ Copyright (C) 2000 Free Software Foundation, Inc.
+ Contributed by Greg McGary <greg@mcgary.org>
+
+ This file is part of the GNU C Library. Its master source is NOT part of
+ the C library, however. The master source lives in the GNU MP 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. */
+
+#define BP_SYM(name) _BP_SYM (name)
+#if __BOUNDED_POINTERS__
+# define _BP_SYM(name) __BP_##name
+#else
+# define _BP_SYM(name) name
+#endif
Index: sysdeps/generic/bp-start.h
===================================================================
RCS file: bp-start.h
diff -N bp-start.h
--- /dev/null Tue May 5 13:32:27 1998
+++ bp-start.h Wed Jun 7 17:16:09 2000
@@ -0,0 +1,69 @@
+/* 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. */
+
+
+#if __BOUNDED_POINTERS__
+
+ /* The command-line arg vector and environment vector come to us from
+ the OS as an unbounded pointer to an array of unbounded strings.
+ The user's main expects argv and __environ to be bounded pointers
+ to arrays of bounded strings. */
+#define INIT_ARGV_and_ENVIRON \
+ do { \
+ int envc; \
+ for (envc = 0; *ubp_ev; ubp_ev++, envc++) \
+ ; \
+ ubp_ev -= envc; \
+ \
+ /* GKM FIXME: we could save some space by allocating only enough for \
+ the additional low & high words, and destructively rewriting \
+ argv in place. */ \
+ __ptrvalue (argv) = __ptrlow (argv) \
+ = alloca ((argc + envc + 2) * sizeof (*argv)); \
+ __ptrhigh (argv) = __ptrvalue (argv) + argc + 1; \
+ __ptrvalue (__environ) = __ptrlow (__environ) = __ptrhigh (argv); \
+ __ptrhigh (__environ) = __ptrvalue (__environ) + envc + 1; \
+ boundify_vector (__environ, ubp_ev); \
+ boundify_vector (argv, ubp_av); \
+ } while (0)
+
+
+/* Copy an unbounded vector of unbounded strings into a bounded counterpart. */
+
+static void
+boundify_vector (char **dest, char *__unbounded *__unbounded src)
+{
+ char *__unbounded s;
+ for (; *src; src++, dest++)
+ {
+ __ptrvalue (*dest) = __ptrlow (*dest) = *src;
+ __ptrhigh (*dest) = src[1];
+ }
+ *dest = 0;
+ /* The OS lays out strings contiguously in vector order,
+ so */
+ for (s = __ptrvalue (dest[-1]); *s; s++)
+ ;
+ __ptrhigh (dest[-1]) = ++s;
+}
+
+#else
+
+# define INIT_ARGV_and_ENVIRON __environ = ubp_ev
+
+#endif
Index: sysdeps/i386/elf/start.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/i386/elf/start.S,v
retrieving revision 1.12
diff -u -p -r1.12 start.S
--- start.S 1998/06/18 17:28:59 1.12
+++ start.S 2000/06/08 00:16:09
@@ -1,5 +1,5 @@
/* Startup code compliant to the ELF i386 ABI.
- Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
+ Copyright (C) 1995, 1996, 1997, 1998, 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
@@ -36,6 +36,8 @@
NULL
*/
+#include "bp-sym.h"
+
.text
.globl _start
_start:
@@ -70,11 +72,11 @@ _start:
pushl %ecx /* Push second argument: argv. */
pushl %esi /* Push first argument: argc. */
- pushl $main
+ pushl $BP_SYM (main)
/* Call the user's main function, and exit with its value.
But let the libc call main. */
- call __libc_start_main
+ call BP_SYM (__libc_start_main)
hlt /* Crash if somehow `exit' does return. */
Index: sysdeps/generic/libc-start.c
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/generic/libc-start.c,v
retrieving revision 1.17
diff -u -p -r1.17 libc-start.c
--- libc-start.c 2000/05/25 04:59:39 1.17
+++ libc-start.c 2000/06/08 00:16:55
@@ -19,22 +19,34 @@
#include <stdlib.h>
#include <unistd.h>
#include <ldsodefs.h>
+#include <bp-start.h>
+#include <bp-sym.h>
extern void __libc_init_first (int argc, char **argv, char **envp);
extern int _dl_starting_up;
weak_extern (_dl_starting_up)
extern int __libc_multiple_libcs;
-extern void *__libc_stack_end;
+extern void *__unbounded __libc_stack_end;
/* Prototype for local function. */
extern void __libc_check_standard_fds (void);
int
-__libc_start_main (int (*main) (int, char **, char **), int argc,
- char **argv, void (*init) (void), void (*fini) (void),
- void (*rtld_fini) (void), void *stack_end)
+/* GKM FIXME: GCC: this should get __BP_ prefix by virtue of the
+ BPs in the arglist of startup_info.main and startup_info.init. */
+BP_SYM (__libc_start_main) (int (*main) (int, char **, char **),
+ int argc, char *__unbounded *__unbounded ubp_av,
+ void (*init) (void), void (*fini) (void),
+ void (*rtld_fini) (void), void *__unbounded stack_end)
{
+ char *__unbounded *__unbounded ubp_ev = &ubp_av[argc + 1];
+#if __BOUNDED_POINTERS__
+ char **argv;
+#else
+# define argv ubp_av
+#endif
+
#ifndef SHARED
/* The next variable is only here to work around a bug in gcc <= 2.7.2.2.
If the address would be taken inside the expression the optimizer
@@ -44,11 +56,10 @@ __libc_start_main (int (*main) (int, cha
__libc_multiple_libcs = dummy_addr && !_dl_starting_up;
#endif
+ INIT_ARGV_and_ENVIRON;
+
/* Store the lowest stack address. */
__libc_stack_end = stack_end;
-
- /* Set the global _environ variable correctly. */
- __environ = &argv[argc + 1];
#ifndef SHARED
/* Some security at this point. Prevent starting a SUID binary where
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