1  /* __libc_siglongjmp for Linux/x86
       2     Copyright (C) 2018-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <sysdeps/x86/longjmp.c>
      20  
      21  #include <pthreadP.h>
      22  #include <jmp_buf-ssp.h>
      23  
      24  #ifdef __x86_64__
      25  # define SHADOW_STACK_POINTER_SIZE 8
      26  #else
      27  # define SHADOW_STACK_POINTER_SIZE 4
      28  #endif
      29  
      30  /* Assert that the priv field in struct pthread_unwind_buf has space
      31     to store shadow stack pointer.  */
      32  _Static_assert ((offsetof (struct pthread_unwind_buf, priv)
      33                  <= SHADOW_STACK_POINTER_OFFSET)
      34                 && ((offsetof (struct pthread_unwind_buf, priv)
      35                      + sizeof (((struct pthread_unwind_buf *) 0)->priv))
      36                     >= (SHADOW_STACK_POINTER_OFFSET
      37                         + SHADOW_STACK_POINTER_SIZE)),
      38                 "Shadow stack pointer is not within private storage "
      39                 "of pthread_unwind_buf.");