The test validates the internal key to be the same in all CPUs.

It performs the validation again with the Suspend-To-RAM (ACPI S3) state.

Signed-off-by: Chang S. Bae chang.seok.bae@intel.com Cc: linux-kernel@vger.kernel.org Cc: linux-kselftest@vger.kernel.org --- Changes from RFC v1: * Commented the binutils version number for ENCODEKEY128 (Peter Zijlstra) --- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/keylocker.c | 177 ++++++++++++++++++++++++ 2 files changed, 178 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/keylocker.c

diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 333980375bc7..09237cc84108 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -13,7 +13,7 @@ CAN_BUILD_WITH_NOPIE := $(shell ./check_cc.sh $(CC) trivial_program.c -no-pie) TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \ check_initial_reg_state sigreturn iopl ioperm \ test_vsyscall mov_ss_trap \ - syscall_arg_fault fsgsbase_restore + syscall_arg_fault fsgsbase_restore keylocker 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/keylocker.c b/tools/testing/selftests/x86/keylocker.c new file mode 100644 index 000000000000..78bbb7939b1a --- /dev/null +++ b/tools/testing/selftests/x86/keylocker.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * keylocker.c, validate the internal key management. + */ +#undef _GNU_SOURCE +#define _GNU_SOURCE 1 + +#include <stdio.h> +#include <stdbool.h> +#include <string.h> +#include <fcntl.h> +#include <err.h> +#include <sched.h> +#include <setjmp.h> +#include <signal.h> +#include <unistd.h> + +#define HANDLE_SIZE 48 + +static bool keylocker_disabled; + +/* Encode a 128-bit key to a 384-bit handle */ +static inline void __encode_key(char *handle) +{ + static const unsigned char aeskey[] = { 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, + 0x71, 0x77, 0x74, 0x69, 0x6f, 0x6b, 0x6c, 0x78 }; + + asm volatile ("movdqu %0, %%xmm0" : : "m" (*aeskey) :); + + /* Set no restriction to the handle */ + asm volatile ("mov $0, %%eax" :); + + /* ENCODEKEY128 %EAX (supported by binutils >= 2.36) */ + asm volatile (".byte 0xf3, 0xf, 0x38, 0xfa, 0xc0"); + + asm volatile ("movdqu %%xmm0, %0; movdqu %%xmm1, %1; movdqu %%xmm2, %2;" + : "=m" (handle[0]), "=m" (handle[0x10]), "=m" (handle[0x20])); +} + +static jmp_buf jmpbuf; + +static void handle_sigill(int sig, siginfo_t *si, void *ctx_void) +{ + keylocker_disabled = true; + siglongjmp(jmpbuf, 1); +} + +static bool encode_key(char *handle) +{ + bool success = true; + struct sigaction sa; + int ret; + + memset(&sa, 0, sizeof(sa)); + + /* Set signal handler */ + sa.sa_flags = SA_SIGINFO; + sa.sa_sigaction = handle_sigill; + sigemptyset(&sa.sa_mask); + ret = sigaction(SIGILL, &sa, 0); + if (ret) + err(1, "sigaction"); + + if (sigsetjmp(jmpbuf, 1)) + success = false; + else + __encode_key(handle); + + /* Clear signal handler */ + sa.sa_flags = 0; + sa.sa_sigaction = NULL; + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + ret = sigaction(SIGILL, &sa, 0); + if (ret) + err(1, "sigaction"); + + return success; +} + +/* + * Test if the internal key is the same in all the CPUs: + * + * Since the value is not readable, compare the encoded output of a AES key + * between CPUs. + */ + +static int nerrs; + +static unsigned char cpu0_handle[HANDLE_SIZE] = { 0 }; + +static void test_internal_key(bool slept, long cpus) +{ + int cpu, errs; + + printf("Test the internal key consistency between CPUs\n"); + + for (cpu = 0, errs = 0; cpu < cpus; cpu++) { + char handle[HANDLE_SIZE] = { 0 }; + cpu_set_t mask; + bool success; + + CPU_ZERO(&mask); + CPU_SET(cpu, &mask); + sched_setaffinity(0, sizeof(cpu_set_t), &mask); + + success = encode_key(handle); + if (!success) { + /* The encode should success after the S3 sleep */ + if (slept) + errs++; + printf("[%s]\tKey Locker disabled at CPU%d\n", + slept ? "FAIL" : "NOTE", cpu); + continue; + } + + if (cpu == 0 && !slept) { + /* Record the first handle value as reference */ + memcpy(cpu0_handle, handle, HANDLE_SIZE); + } else if (memcmp(cpu0_handle, handle, HANDLE_SIZE)) { + printf("[FAIL]\tMismatched internal key at CPU%d\n", + cpu); + errs++; + } + } + + if (errs == 0 && !keylocker_disabled) + printf("[OK]\tAll the internal keys are the same\n"); + else + nerrs += errs; +} + +static void switch_to_sleep(bool *slept) +{ + ssize_t bytes; + int fd; + + printf("Transition to Suspend-To-RAM state\n"); + + fd = open("/sys/power/mem_sleep", O_RDWR); + if (fd < 0) + err(1, "Open /sys/power/mem_sleep"); + + bytes = write(fd, "deep", strlen("deep")); + if (bytes != strlen("deep")) + err(1, "Write /sys/power/mem_sleep"); + close(fd); + + fd = open("/sys/power/state", O_RDWR); + if (fd < 0) + err(1, "Open /sys/power/state"); + + bytes = write(fd, "mem", strlen("mem")); + if (bytes != strlen("mem")) + err(1, "Write /sys/power/state"); + close(fd); + + printf("Wake up from Suspend-To-RAM state\n"); + *slept = true; +} + +int main(void) +{ + bool slept = false; + long cpus; + + cpus = sysconf(_SC_NPROCESSORS_ONLN); + printf("%ld CPUs in the system\n", cpus); + + test_internal_key(slept, cpus); + if (keylocker_disabled) + return nerrs ? 1 : 0; + + switch_to_sleep(&slept); + test_internal_key(slept, cpus); + return nerrs ? 1 : 0; +}