sysdeps/unix/sysv/linux/s390/s390-64/____longjmp_chk.c

   1 /* Copyright (C) 2009-2022 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <sysdep.h>
  20 #include <setjmp.h>
  21 #include <bits/setjmp.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <stdio.h>
  25 #include <stdint.h>
  26 #include <signal.h>
  27 #include <sys/syscall.h>
  28
  29 #define __longjmp ____longjmp_chk
  30
  31 #define CHECK_SP(env, guard) \
  32   do                                                                    \
  33     {                                                                   \
  34       uintptr_t cur_sp;                                                 \
  35       uintptr_t new_sp = env->__gregs[9];                               \
  36       __asm__ ("lgr %0, %%r15" : "=r" (cur_sp));                        \
  37       new_sp ^= guard;                                                  \
  38       if (new_sp < cur_sp)                                              \
  39         {                                                               \
  40           stack_t oss;                                                  \
  41           int res = INTERNAL_SYSCALL_CALL (sigaltstack, NULL, &oss);    \
  42           if (!INTERNAL_SYSCALL_ERROR_P (res))                          \
  43             {                                                           \
  44               if ((oss.ss_flags & SS_ONSTACK) == 0                      \
  45                   || ((uintptr_t) (oss.ss_sp + oss.ss_size) - new_sp    \
  46                       < oss.ss_size))                                   \
  47                 __fortify_fail ("longjmp causes uninitialized stack frame");\
  48             }                                                           \
  49         }                                                               \
  50     } while (0)
  51
  52 #include "__longjmp.c"