[PATCH v4 20/21] kselftest/arm64: Add coverage of the ZT ptrace regset
Mark Brown
broonie at kernel.org
Mon Jan 16 08:04:55 PST 2023
Add coverage of the ZT ptrace interface.
Signed-off-by: Mark Brown <broonie at kernel.org>
---
tools/testing/selftests/arm64/fp/.gitignore | 1 +
tools/testing/selftests/arm64/fp/Makefile | 2 +
tools/testing/selftests/arm64/fp/zt-ptrace.c | 365 +++++++++++++++++++++++++++
3 files changed, 368 insertions(+)
diff --git a/tools/testing/selftests/arm64/fp/.gitignore b/tools/testing/selftests/arm64/fp/.gitignore
index 41bde4c97d47..ebc86757bdd8 100644
--- a/tools/testing/selftests/arm64/fp/.gitignore
+++ b/tools/testing/selftests/arm64/fp/.gitignore
@@ -12,4 +12,5 @@ vlset
za-fork
za-ptrace
za-test
+zt-ptrace
zt-test
diff --git a/tools/testing/selftests/arm64/fp/Makefile b/tools/testing/selftests/arm64/fp/Makefile
index aff3026d3dff..50a70220ba6c 100644
--- a/tools/testing/selftests/arm64/fp/Makefile
+++ b/tools/testing/selftests/arm64/fp/Makefile
@@ -14,6 +14,7 @@ TEST_GEN_PROGS_EXTENDED := fp-pidbench fpsimd-test \
sve-test \
ssve-test \
za-test \
+ zt-ptrace \
zt-test \
vlset
TEST_PROGS_EXTENDED := fpsimd-stress sve-stress ssve-stress za-stress
@@ -42,6 +43,7 @@ $(OUTPUT)/za-fork: za-fork.c $(OUTPUT)/za-fork-asm.o
$(OUTPUT)/za-ptrace: za-ptrace.c
$(OUTPUT)/za-test: za-test.S $(OUTPUT)/asm-utils.o
$(CC) -nostdlib $^ -o $@
+$(OUTPUT)/zt-ptrace: zt-ptrace.c
$(OUTPUT)/zt-test: zt-test.S $(OUTPUT)/asm-utils.o
$(CC) -nostdlib $^ -o $@
diff --git a/tools/testing/selftests/arm64/fp/zt-ptrace.c b/tools/testing/selftests/arm64/fp/zt-ptrace.c
new file mode 100644
index 000000000000..996d9614a131
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/zt-ptrace.c
@@ -0,0 +1,365 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 ARM Limited.
+ */
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/wait.h>
+#include <asm/sigcontext.h>
+#include <asm/ptrace.h>
+
+#include "../../kselftest.h"
+
+/* <linux/elf.h> and <sys/auxv.h> don't like each other, so: */
+#ifndef NT_ARM_ZA
+#define NT_ARM_ZA 0x40c
+#endif
+#ifndef NT_ARM_ZT
+#define NT_ARM_ZT 0x40d
+#endif
+
+#define EXPECTED_TESTS 3
+
+static int sme_vl;
+
+static void fill_buf(char *buf, size_t size)
+{
+ int i;
+
+ for (i = 0; i < size; i++)
+ buf[i] = random();
+}
+
+static int do_child(void)
+{
+ if (ptrace(PTRACE_TRACEME, -1, NULL, NULL))
+ ksft_exit_fail_msg("PTRACE_TRACEME", strerror(errno));
+
+ if (raise(SIGSTOP))
+ ksft_exit_fail_msg("raise(SIGSTOP)", strerror(errno));
+
+ return EXIT_SUCCESS;
+}
+
+static struct user_za_header *get_za(pid_t pid, void **buf, size_t *size)
+{
+ struct user_za_header *za;
+ void *p;
+ size_t sz = sizeof(*za);
+ struct iovec iov;
+
+ while (1) {
+ if (*size < sz) {
+ p = realloc(*buf, sz);
+ if (!p) {
+ errno = ENOMEM;
+ goto error;
+ }
+
+ *buf = p;
+ *size = sz;
+ }
+
+ iov.iov_base = *buf;
+ iov.iov_len = sz;
+ if (ptrace(PTRACE_GETREGSET, pid, NT_ARM_ZA, &iov))
+ goto error;
+
+ za = *buf;
+ if (za->size <= sz)
+ break;
+
+ sz = za->size;
+ }
+
+ return za;
+
+error:
+ return NULL;
+}
+
+static int set_za(pid_t pid, const struct user_za_header *za)
+{
+ struct iovec iov;
+
+ iov.iov_base = (void *)za;
+ iov.iov_len = za->size;
+ return ptrace(PTRACE_SETREGSET, pid, NT_ARM_ZA, &iov);
+}
+
+static int get_zt(pid_t pid, char zt[ZT_SIG_REG_BYTES])
+{
+ struct iovec iov;
+
+ iov.iov_base = zt;
+ iov.iov_len = ZT_SIG_REG_BYTES;
+ return ptrace(PTRACE_GETREGSET, pid, NT_ARM_ZT, &iov);
+}
+
+
+static int set_zt(pid_t pid, const char zt[ZT_SIG_REG_BYTES])
+{
+ struct iovec iov;
+
+ iov.iov_base = (void *)zt;
+ iov.iov_len = ZT_SIG_REG_BYTES;
+ return ptrace(PTRACE_SETREGSET, pid, NT_ARM_ZT, &iov);
+}
+
+/* Reading with ZA disabled returns all zeros */
+static void ptrace_za_disabled_read_zt(pid_t child)
+{
+ struct user_za_header za;
+ char zt[ZT_SIG_REG_BYTES];
+ int ret, i;
+ bool fail = false;
+
+ /* Disable PSTATE.ZA using the ZA interface */
+ memset(&za, 0, sizeof(za));
+ za.vl = sme_vl;
+ za.size = sizeof(za);
+
+ ret = set_za(child, &za);
+ if (ret != 0) {
+ ksft_print_msg("Failed to disable ZA\n");
+ fail = true;
+ }
+
+ /* Read back ZT */
+ ret = get_zt(child, zt);
+ if (ret != 0) {
+ ksft_print_msg("Failed to read ZT\n");
+ fail = true;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(zt); i++) {
+ if (zt[i]) {
+ ksft_print_msg("zt[%d]: 0x%x != 0\n", i, zt[i]);
+ fail = true;
+ }
+ }
+
+ ksft_test_result(!fail, "ptrace_za_disabled_read_zt\n");
+}
+
+/* Writing then reading ZT should return the data written */
+static void ptrace_set_get_zt(pid_t child)
+{
+ char zt_in[ZT_SIG_REG_BYTES];
+ char zt_out[ZT_SIG_REG_BYTES];
+ int ret, i;
+ bool fail = false;
+
+ fill_buf(zt_in, sizeof(zt_in));
+
+ ret = set_zt(child, zt_in);
+ if (ret != 0) {
+ ksft_print_msg("Failed to set ZT\n");
+ fail = true;
+ }
+
+ ret = get_zt(child, zt_out);
+ if (ret != 0) {
+ ksft_print_msg("Failed to read ZT\n");
+ fail = true;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(zt_in); i++) {
+ if (zt_in[i] != zt_out[i]) {
+ ksft_print_msg("zt[%d]: 0x%x != 0x%x\n", i,
+ zt_in[i], zt_out[i]);
+ fail = true;
+ }
+ }
+
+ ksft_test_result(!fail, "ptrace_set_get_zt\n");
+}
+
+/* Writing ZT should set PSTATE.ZA */
+static void ptrace_enable_za_via_zt(pid_t child)
+{
+ struct user_za_header za_in;
+ struct user_za_header *za_out;
+ char zt[ZT_SIG_REG_BYTES];
+ char *za_data;
+ size_t za_out_size;
+ int ret, i, vq;
+ bool fail = false;
+
+ /* Disable PSTATE.ZA using the ZA interface */
+ memset(&za_in, 0, sizeof(za_in));
+ za_in.vl = sme_vl;
+ za_in.size = sizeof(za_in);
+
+ ret = set_za(child, &za_in);
+ if (ret != 0) {
+ ksft_print_msg("Failed to disable ZA\n");
+ fail = true;
+ }
+
+ /* Write ZT */
+ fill_buf(zt, sizeof(zt));
+ ret = set_zt(child, zt);
+ if (ret != 0) {
+ ksft_print_msg("Failed to set ZT\n");
+ fail = true;
+ }
+
+ /* Read back ZA and check for register data */
+ za_out = NULL;
+ za_out_size = 0;
+ if (get_za(child, (void **)&za_out, &za_out_size)) {
+ /* Should have an unchanged VL */
+ if (za_out->vl != sme_vl) {
+ ksft_print_msg("VL changed from %d to %d\n",
+ sme_vl, za_out->vl);
+ fail = true;
+ }
+ vq = __sve_vq_from_vl(za_out->vl);
+ za_data = (char *)za_out + ZA_PT_ZA_OFFSET;
+
+ /* Should have register data */
+ if (za_out->size < ZA_PT_SIZE(vq)) {
+ ksft_print_msg("ZA data less than expected: %u < %u\n",
+ za_out->size, ZA_PT_SIZE(vq));
+ fail = true;
+ vq = 0;
+ }
+
+ /* That register data should be non-zero */
+ for (i = 0; i < ZA_PT_ZA_SIZE(vq); i++) {
+ if (za_data[i]) {
+ ksft_print_msg("ZA byte %d is %x\n",
+ i, za_data[i]);
+ fail = true;
+ }
+ }
+ } else {
+ ksft_print_msg("Failed to read ZA\n");
+ fail = true;
+ }
+
+ ksft_test_result(!fail, "ptrace_enable_za_via_zt\n");
+}
+
+static int do_parent(pid_t child)
+{
+ int ret = EXIT_FAILURE;
+ pid_t pid;
+ int status;
+ siginfo_t si;
+
+ /* Attach to the child */
+ while (1) {
+ int sig;
+
+ pid = wait(&status);
+ if (pid == -1) {
+ perror("wait");
+ goto error;
+ }
+
+ /*
+ * This should never happen but it's hard to flag in
+ * the framework.
+ */
+ if (pid != child)
+ continue;
+
+ if (WIFEXITED(status) || WIFSIGNALED(status))
+ ksft_exit_fail_msg("Child died unexpectedly\n");
+
+ if (!WIFSTOPPED(status))
+ goto error;
+
+ sig = WSTOPSIG(status);
+
+ if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &si)) {
+ if (errno == ESRCH)
+ goto disappeared;
+
+ if (errno == EINVAL) {
+ sig = 0; /* bust group-stop */
+ goto cont;
+ }
+
+ ksft_test_result_fail("PTRACE_GETSIGINFO: %s\n",
+ strerror(errno));
+ goto error;
+ }
+
+ if (sig == SIGSTOP && si.si_code == SI_TKILL &&
+ si.si_pid == pid)
+ break;
+
+ cont:
+ if (ptrace(PTRACE_CONT, pid, NULL, sig)) {
+ if (errno == ESRCH)
+ goto disappeared;
+
+ ksft_test_result_fail("PTRACE_CONT: %s\n",
+ strerror(errno));
+ goto error;
+ }
+ }
+
+ ksft_print_msg("Parent is %d, child is %d\n", getpid(), child);
+
+ ptrace_za_disabled_read_zt(child);
+ ptrace_set_get_zt(child);
+ ptrace_enable_za_via_zt(child);
+
+ ret = EXIT_SUCCESS;
+
+error:
+ kill(child, SIGKILL);
+
+disappeared:
+ return ret;
+}
+
+int main(void)
+{
+ int ret = EXIT_SUCCESS;
+ pid_t child;
+
+ srandom(getpid());
+
+ ksft_print_header();
+
+ if (!(getauxval(AT_HWCAP2) & HWCAP2_SME2)) {
+ ksft_set_plan(1);
+ ksft_exit_skip("SME2 not available\n");
+ }
+
+ /* We need a valid SME VL to enable/disable ZA */
+ sme_vl = prctl(PR_SME_GET_VL);
+ if (sme_vl == -1) {
+ ksft_set_plan(1);
+ ksft_exit_skip("Failed to read SME VL: %d (%s)\n",
+ errno, strerror(errno));
+ }
+
+ ksft_set_plan(EXPECTED_TESTS);
+
+ child = fork();
+ if (!child)
+ return do_child();
+
+ if (do_parent(child))
+ ret = EXIT_FAILURE;
+
+ ksft_print_cnts();
+
+ return ret;
+}
--
2.34.1
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