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Message-Id: <20210514201508.27967-8-chang.seok.bae@intel.com>
Date: Fri, 14 May 2021 13:15:04 -0700
From: "Chang S. Bae" <chang.seok.bae@...el.com>
To: tglx@...utronix.de, mingo@...nel.org, bp@...e.de, luto@...nel.org,
x86@...nel.org, herbert@...dor.apana.org.au
Cc: dan.j.williams@...el.com, dave.hansen@...el.com,
ravi.v.shankar@...el.com, linux-crypto@...r.kernel.org,
linux-kernel@...r.kernel.org, chang.seok.bae@...el.com,
linux-kselftest@...r.kernel.org
Subject: [RFC PATCH v2 07/11] selftests/x86: Test Key Locker internal key maintenance
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@...el.com>
Cc: linux-kernel@...r.kernel.org
Cc: linux-kselftest@...r.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;
+}
--
2.17.1
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