Introduce a quick test to verify shadow stack and IBT are working. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> --- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/cet_quick_test.c | 128 +++++++++++++++++++ 2 files changed, 129 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/cet_quick_test.c diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index f1bf5ab87160..26e68272117a 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -14,7 +14,7 @@ CAN_BUILD_CET := $(shell ./check_cc.sh $(CC) trivial_program.c -fcf-protection) TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \ check_initial_reg_state sigreturn iopl ioperm \ protection_keys test_vdso test_vsyscall mov_ss_trap \ - syscall_arg_fault + syscall_arg_fault cet_quick_test TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer diff --git a/tools/testing/selftests/x86/cet_quick_test.c b/tools/testing/selftests/x86/cet_quick_test.c new file mode 100644 index 000000000000..e84bbbcfd26f --- /dev/null +++ b/tools/testing/selftests/x86/cet_quick_test.c @@ -0,0 +1,128 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Quick tests to verify Shadow Stack and IBT are working */ + +#include <stdio.h> +#include <stdlib.h> +#include <signal.h> +#include <string.h> +#include <ucontext.h> + +ucontext_t ucp; +int result[4] = {-1, -1, -1, -1}; +int test_id; + +void stack_hacked(unsigned long x) +{ + result[test_id] = -1; + test_id++; + setcontext(&ucp); +} + +#pragma GCC push_options +#pragma GCC optimize ("O0") +void ibt_violation(void) +{ +#ifdef __i386__ + asm volatile("lea 1f, %eax"); + asm volatile("jmp *%eax"); +#else + asm volatile("lea 1f, %rax"); + asm volatile("jmp *%rax"); +#endif + asm volatile("1:"); + result[test_id] = -1; + test_id++; + setcontext(&ucp); +} + +void shstk_violation(void) +{ +#ifdef __i386__ + unsigned long x = 0; + + ((unsigned long *)&x)[2] = (unsigned long)stack_hacked; +#else + unsigned long long x = 0; + + ((unsigned long long *)&x)[2] = (unsigned long)stack_hacked; +#endif +} +#pragma GCC pop_options + +void segv_handler(int signum, siginfo_t *si, void *uc) +{ + result[test_id] = 0; + test_id++; + setcontext(&ucp); +} + +void user1_handler(int signum, siginfo_t *si, void *uc) +{ + shstk_violation(); +} + +void user2_handler(int signum, siginfo_t *si, void *uc) +{ + ibt_violation(); +} + +int main(int argc, char *argv[]) +{ + struct sigaction sa; + int r; + + r = sigemptyset(&sa.sa_mask); + if (r) + return -1; + + sa.sa_flags = SA_SIGINFO; + + /* + * Control protection fault handler + */ + sa.sa_sigaction = segv_handler; + r = sigaction(SIGSEGV, &sa, NULL); + if (r) + return -1; + + /* + * Handler to test Shadow stack + */ + sa.sa_sigaction = user1_handler; + r = sigaction(SIGUSR1, &sa, NULL); + if (r) + return -1; + + /* + * Handler to test IBT + */ + sa.sa_sigaction = user2_handler; + r = sigaction(SIGUSR2, &sa, NULL); + if (r) + return -1; + + test_id = 0; + r = getcontext(&ucp); + if (r) + return -1; + + if (test_id == 0) + shstk_violation(); + else if (test_id == 1) + ibt_violation(); + else if (test_id == 2) + raise(SIGUSR1); + else if (test_id == 3) + raise(SIGUSR2); + + r = 0; + printf("[%s]\tShadow stack\n", result[0] ? "FAIL":"OK"); + r += result[0]; + printf("[%s]\tIBT\n", result[1] ? "FAIL":"OK"); + r += result[1]; + printf("[%s]\tShadow stack in signal\n", result[2] ? "FAIL":"OK"); + r += result[2]; + printf("[%s]\tIBT in signal\n", result[3] ? "FAIL":"OK"); + r += result[3]; + return r; +} -- 2.21.0