1 /* Copyright (C) 2009-2021 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"
53