161 lines
4.1 KiB
C++
161 lines
4.1 KiB
C++
// relro_test.cc -- test -z relro for gold
|
|
|
|
// Copyright (C) 2008-2022 Free Software Foundation, Inc.
|
|
// Written by Ian Lance Taylor <iant@google.com>.
|
|
|
|
// This file is part of gold.
|
|
|
|
// This program 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 of the License, or
|
|
// (at your option) any later version.
|
|
|
|
// This program 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.
|
|
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with this program; if not, write to the Free Software
|
|
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
|
|
// MA 02110-1301, USA.
|
|
|
|
#include <cassert>
|
|
#include <csignal>
|
|
#include <cstdio>
|
|
#include <cstdlib>
|
|
#include <exception>
|
|
#include <stdint.h>
|
|
#include <unistd.h>
|
|
|
|
// This tests we were linked with a script. If we were linked with a
|
|
// script, relro currently does not work.
|
|
|
|
extern char using_script[] __attribute__ ((weak));
|
|
|
|
// This code is put into a shared library linked with -z relro.
|
|
|
|
// i1 and i2 are not relro variables.
|
|
int i1 = 1;
|
|
static int i2 = 2;
|
|
|
|
// P1 is a global relro variable.
|
|
int* const p1 __attribute__ ((aligned(64))) = &i1;
|
|
|
|
// P2 is a local relro variable.
|
|
int* const p2 __attribute__ ((aligned(64))) = &i2;
|
|
|
|
// Add a TLS variable to make sure -z relro works correctly with TLS.
|
|
__thread int i3 = 1;
|
|
|
|
// Test symbol addresses.
|
|
|
|
bool
|
|
t1()
|
|
{
|
|
if (using_script)
|
|
return true;
|
|
|
|
void* i1addr = static_cast<void*>(&i1);
|
|
void* i2addr = static_cast<void*>(&i2);
|
|
const void* p1addr = static_cast<const void*>(&p1);
|
|
const void* p2addr = static_cast<const void*>(&p2);
|
|
|
|
// The relro variables should precede the non-relro variables in the
|
|
// memory image.
|
|
assert(i1addr > p1addr);
|
|
assert(i1addr > p2addr);
|
|
assert(i2addr > p1addr);
|
|
assert(i2addr > p2addr);
|
|
|
|
// The relro variables should not be on the same page as the
|
|
// non-relro variables.
|
|
const size_t page_size = getpagesize();
|
|
uintptr_t i1page = reinterpret_cast<uintptr_t>(i1addr) & ~ (page_size - 1);
|
|
uintptr_t i2page = reinterpret_cast<uintptr_t>(i2addr) & ~ (page_size - 1);
|
|
uintptr_t p1page = reinterpret_cast<uintptr_t>(p1addr) & ~ (page_size - 1);
|
|
uintptr_t p2page = reinterpret_cast<uintptr_t>(p2addr) & ~ (page_size - 1);
|
|
assert(i1page != p1page);
|
|
assert(i1page != p2page);
|
|
assert(i2page != p1page);
|
|
assert(i2page != p2page);
|
|
assert(i3 == 1);
|
|
|
|
return true;
|
|
}
|
|
|
|
// Tell terminate handler that we are throwing from a signal handler.
|
|
|
|
static bool throwing;
|
|
|
|
// A signal handler for SIGSEGV.
|
|
|
|
extern "C"
|
|
void
|
|
sigsegv_handler(int)
|
|
{
|
|
throwing = true;
|
|
throw 0;
|
|
}
|
|
|
|
// The original terminate handler.
|
|
|
|
std::terminate_handler orig_terminate;
|
|
|
|
// Throwing an exception out of a signal handler doesn't always work
|
|
// reliably. When that happens the program will call terminate. We
|
|
// set a terminate handler to indicate that the test probably passed.
|
|
|
|
void
|
|
terminate_handler()
|
|
{
|
|
if (!throwing)
|
|
{
|
|
orig_terminate();
|
|
::exit(EXIT_FAILURE);
|
|
}
|
|
fprintf(stderr,
|
|
"relro_test: terminate called due to failure to throw through signal handler\n");
|
|
fprintf(stderr, "relro_test: assuming test succeeded\n");
|
|
::exit(EXIT_SUCCESS);
|
|
}
|
|
|
|
// Use a separate function to throw the exception, so that we don't
|
|
// need to use -fnon-call-exceptions.
|
|
|
|
void f2() __attribute__ ((noinline));
|
|
void
|
|
f2()
|
|
{
|
|
int** pp1 = const_cast<int**>(&p1);
|
|
*pp1 = &i2;
|
|
|
|
// We shouldn't get here--the assignment to *pp1 should write to
|
|
// memory which the dynamic linker marked as read-only, giving us a
|
|
// SIGSEGV, causing sigsegv_handler to be invoked, to throw past us.
|
|
assert(0);
|
|
}
|
|
|
|
// Changing a relro variable should give us a SIGSEGV.
|
|
|
|
bool
|
|
t2()
|
|
{
|
|
if (using_script)
|
|
return true;
|
|
|
|
signal(SIGSEGV, sigsegv_handler);
|
|
orig_terminate = std::set_terminate(terminate_handler);
|
|
|
|
try
|
|
{
|
|
f2();
|
|
return false;
|
|
}
|
|
catch (int i)
|
|
{
|
|
assert(i == 0);
|
|
return true;
|
|
}
|
|
}
|