glibc/sysdeps/unix/sysv/linux/x86_64/dl-cet.h

48 lines
1.8 KiB
C

/* Linux/x86-64 CET initializers function.
Copyright (C) 2023-2024 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
#include <cpu-features-offsets.h>
#include_next <dl-cet.h>
#define X86_STRINGIFY_1(x) #x
#define X86_STRINGIFY(x) X86_STRINGIFY_1 (x)
/* Enable shadow stack before calling _dl_init if it is enabled in
GL(dl_x86_feature_1). Call _dl_setup_x86_features to setup shadow
stack. */
#define RTLD_START_ENABLE_X86_FEATURES \
"\
# Check if shadow stack is enabled in GL(dl_x86_feature_1).\n\
movl _rtld_local+" X86_STRINGIFY (RTLD_GLOBAL_DL_X86_FEATURE_1_OFFSET) "(%rip), %edx\n\
testl $" X86_STRINGIFY (X86_FEATURE_1_SHSTK) ", %edx\n\
jz 1f\n\
# Enable shadow stack if enabled in GL(dl_x86_feature_1).\n\
movl $" X86_STRINGIFY (ARCH_SHSTK_SHSTK) ", %esi\n\
movl $" X86_STRINGIFY (ARCH_SHSTK_ENABLE) ", %edi\n\
movl $" X86_STRINGIFY (__NR_arch_prctl) ", %eax\n\
syscall\n\
1:\n\
# Pass GL(dl_x86_feature_1) to _dl_cet_setup_features.\n\
movl %edx, %edi\n\
# Align stack for the _dl_cet_setup_features call.\n\
andq $-16, %rsp\n\
call _dl_cet_setup_features\n\
# Restore %rax and %rsp from %r12 and %r13.\n\
movq %r12, %rax\n\
movq %r13, %rsp\n\
"