gcc/libgcc/enable-execute-stack-mprote...

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netbsd.h (ENABLE_EXECUTE_STACK): Remove. 2011-05-29 Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> Joseph Myers <joseph@codesourcery.com> gcc: * config/alpha/netbsd.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/alpha/osf5.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/darwin.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/i386/mingw32.h (MINGW_ENABLE_EXECUTE_STACK): Remove. (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. [IN_LIBGCC2]: Don't include <windows.h>. * config/i386/netbsd-elf.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/i386/netbsd64.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/netbsd.h (NETBSD_ENABLE_EXECUTE_STACK): Remove. * config/openbsd.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/sol2.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/sparc/freebsd.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/sparc/netbsd-elf.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/alpha/alpha.c (alpha_trampoline_init): Test HAVE_ENABLE_EXECUTE_STACK. * config/i386/i386.c (ix86_trampoline_init): Likewise. * config/sparc/sparc.c (sparc32_initialize_trampoline): Likewise. (sparc64_initialize_trampoline): Likewise. * libgcc2.c [L_enable_execute_stack]: Remove. * system.h (ENABLE_EXECUTE_STACK): Poison. * doc/tm.texi.in (Trampolines, ENABLE_EXECUTE_STACK): Remove. * doc/tm.texi: Regenerate. * Makefile.in (LIBGCC2_CFLAGS): Add -fbuilding-libgcc. gcc/c-family: * c.opt (fbuilding-libgcc): New option. * c-cppbuiltin.c (c_cpp_builtins): Define __LIBGCC_TRAMPOLINE_SIZE__ if flag_building_libgcc. libgcc: * enable-execute-stack-empty.c: New file. * enable-execute-stack-mprotect.c: New file. * config/i386/enable-execute-stack-mingw32.c: New file. * config.host (enable_execute_stack): New variable. Select appropriate variants. * configure.ac: Link enable-execute-stack.c to $enable_execute_stack. * configure: Regenerate. * Makefile.in (LIB2ADD): Add enable-execute-stack.c. (lib2funcs): Remove _enable_execute_stack. Co-Authored-By: Joseph Myers <joseph@codesourcery.com> From-SVN: r174843
2011-06-09 14:30:46 +02:00
/* Implement __enable_execute_stack using mprotect(2).
Copyright (C) 2011, 2012 Free Software Foundation, Inc.
netbsd.h (ENABLE_EXECUTE_STACK): Remove. 2011-05-29 Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> Joseph Myers <joseph@codesourcery.com> gcc: * config/alpha/netbsd.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/alpha/osf5.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/darwin.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/i386/mingw32.h (MINGW_ENABLE_EXECUTE_STACK): Remove. (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. [IN_LIBGCC2]: Don't include <windows.h>. * config/i386/netbsd-elf.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/i386/netbsd64.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/netbsd.h (NETBSD_ENABLE_EXECUTE_STACK): Remove. * config/openbsd.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/sol2.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/sparc/freebsd.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/sparc/netbsd-elf.h (ENABLE_EXECUTE_STACK): Remove. (HAVE_ENABLE_EXECUTE_STACK): Define. * config/alpha/alpha.c (alpha_trampoline_init): Test HAVE_ENABLE_EXECUTE_STACK. * config/i386/i386.c (ix86_trampoline_init): Likewise. * config/sparc/sparc.c (sparc32_initialize_trampoline): Likewise. (sparc64_initialize_trampoline): Likewise. * libgcc2.c [L_enable_execute_stack]: Remove. * system.h (ENABLE_EXECUTE_STACK): Poison. * doc/tm.texi.in (Trampolines, ENABLE_EXECUTE_STACK): Remove. * doc/tm.texi: Regenerate. * Makefile.in (LIBGCC2_CFLAGS): Add -fbuilding-libgcc. gcc/c-family: * c.opt (fbuilding-libgcc): New option. * c-cppbuiltin.c (c_cpp_builtins): Define __LIBGCC_TRAMPOLINE_SIZE__ if flag_building_libgcc. libgcc: * enable-execute-stack-empty.c: New file. * enable-execute-stack-mprotect.c: New file. * config/i386/enable-execute-stack-mingw32.c: New file. * config.host (enable_execute_stack): New variable. Select appropriate variants. * configure.ac: Link enable-execute-stack.c to $enable_execute_stack. * configure: Regenerate. * Makefile.in (LIB2ADD): Add enable-execute-stack.c. (lib2funcs): Remove _enable_execute_stack. Co-Authored-By: Joseph Myers <joseph@codesourcery.com> From-SVN: r174843
2011-06-09 14:30:46 +02:00
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC 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 General Public License
for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include <sys/mman.h>
#include <unistd.h>
#include <stdlib.h>
#define STACK_PROT_RWX (PROT_READ | PROT_WRITE | PROT_EXEC)
static int need_enable_exec_stack;
static void check_enabling (void) __attribute__ ((unused));
extern void __enable_execute_stack (void *);
#if defined __FreeBSD__
#include <sys/sysctl.h>
static void __attribute__ ((constructor))
check_enabling (void)
{
int prot = 0;
size_t len = sizeof (prot);
sysctlbyname ("kern.stackprot", &prot, &len, NULL, 0);
if (prot != STACK_PROT_RWX)
need_enable_exec_stack = 1;
}
#elif defined __sun__ && defined __svr4__
static void __attribute__ ((constructor))
check_enabling (void)
{
int prot = (int) sysconf (_SC_STACK_PROT);
if (prot != STACK_PROT_RWX)
need_enable_exec_stack = 1;
}
#else
/* There is no way to query the execute permission of the stack, so
we always issue the mprotect() call. */
static int need_enable_exec_stack = 1;
#endif
/* Attempt to turn on access permissions for the stack. Unfortunately it
is not possible to make this namespace-clean.*/
void
__enable_execute_stack (void *addr)
{
if (!need_enable_exec_stack)
return;
else
{
static long size, mask;
if (size == 0) {
size = getpagesize ();
mask = ~(size - 1);
}
char *page = (char *) (((long) addr) & mask);
char *end = (char *)
((((long) (addr + __LIBGCC_TRAMPOLINE_SIZE__)) & mask) + size);
if (mprotect (page, end - page, STACK_PROT_RWX) < 0)
/* Note that no errors should be emitted by this code; it is
considered dangerous for library calls to send messages to
stdout/stderr. */
abort ();
}
}