gold/testsuite/copy_test_relro.cc

   1 // copy_test_relro.cc -- test copy relocs against read-only and relro symbols.
   2
   3 // Copyright (C) 2016-2020 Free Software Foundation, Inc.
   4 // Written by Cary Coutant <ccoutant@gmail.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include <cassert>
  24 #include <stdint.h>
  25 #include <signal.h>
  26 #include <setjmp.h>
  27
  28 extern int* const p;
  29 extern const int b[];
  30 extern const int* const q;
  31 extern const int c;
  32 int a = 123;
  33
  34 extern const int* const cp __attribute__ ((section (".rodata"))) = &c;
  35 extern const int* const* const qp __attribute__ ((section (".rodata"))) = &q;
  36
  37 volatile int segfaults = 0;
  38 sigjmp_buf jmp;
  39
  40 void segv(int)
  41 {
  42   ++segfaults;
  43   siglongjmp(jmp, 1);
  44 }
  45
  46 int main()
  47 {
  48   assert(*p == 123);
  49   assert(b[0] == 100);
  50   assert(b[1] == 200);
  51   assert(b[2] == 300);
  52   assert(b[3] == 400);
  53   assert(c == 500);
  54
  55   struct sigaction act;
  56   act.sa_handler = segv;
  57   sigemptyset(&act.sa_mask);
  58   act.sa_flags = 0;
  59   sigaction(SIGSEGV, &act, 0);
  60
  61   assert(segfaults == 0);
  62   if (sigsetjmp(jmp, 1) == 0)
  63     *const_cast<const int **>(&p) = &c;
  64   assert(segfaults == 1);
  65   if (sigsetjmp(jmp, 1) == 0)
  66     *const_cast<int *>(b) = 99;
  67   assert(segfaults == 2);
  68   if (sigsetjmp(jmp, 1) == 0)
  69     *const_cast<int *>(cp) = c - 1;
  70   assert(segfaults == 3);
  71   if (sigsetjmp(jmp, 1) == 0)
  72     *const_cast<int **>(qp) = &a;
  73   assert(segfaults == 4);
  74
  75   return 0;
  76 }