From 5a3140b48978f0f690a5fee2f4a53705c02aabac Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Wed, 21 Apr 2021 19:49:50 +0200 Subject: x86: Restore compile-time check for shadow stack pointer in longjmp --- sysdeps/unix/sysv/linux/x86/longjmp.c | 39 +++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/x86/longjmp.c (limited to 'sysdeps/unix/sysv/linux/x86/longjmp.c') diff --git a/sysdeps/unix/sysv/linux/x86/longjmp.c b/sysdeps/unix/sysv/linux/x86/longjmp.c new file mode 100644 index 0000000000..1cc8b8dfad --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86/longjmp.c @@ -0,0 +1,39 @@ +/* __libc_siglongjmp for Linux/x86 + Copyright (C) 2018-2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include + +#include +#include + +#ifdef __x86_64__ +# define SHADOW_STACK_POINTER_SIZE 8 +#else +# define SHADOW_STACK_POINTER_SIZE 4 +#endif + +/* Assert that the priv field in struct pthread_unwind_buf has space + to store shadow stack pointer. */ +_Static_assert ((offsetof (struct pthread_unwind_buf, priv) + <= SHADOW_STACK_POINTER_OFFSET) + && ((offsetof (struct pthread_unwind_buf, priv) + + sizeof (((struct pthread_unwind_buf *) 0)->priv)) + >= (SHADOW_STACK_POINTER_OFFSET + + SHADOW_STACK_POINTER_SIZE)), + "Shadow stack pointer is not within private storage " + "of pthread_unwind_buf."); -- cgit 1.4.1