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kselftest/arm64: Add coverage of the ZT ptrace regset
Add coverage of the ZT ptrace interface. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20221208-arm64-sme2-v4-20-f2fa0aef982f@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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‎tools/testing/selftests/arm64/fp/.gitignore‎

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@@ -12,4 +12,5 @@ vlset
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za-fork
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za-ptrace
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za-test
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zt-ptrace
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zt-test

‎tools/testing/selftests/arm64/fp/Makefile‎

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@@ -14,6 +14,7 @@ TEST_GEN_PROGS_EXTENDED := fp-pidbench fpsimd-test \
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sve-test \
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ssve-test \
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za-test \
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zt-ptrace \
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zt-test \
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vlset
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TEST_PROGS_EXTENDED := fpsimd-stress sve-stress ssve-stress za-stress
@@ -42,6 +43,7 @@ $(OUTPUT)/za-fork: za-fork.c $(OUTPUT)/za-fork-asm.o
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$(OUTPUT)/za-ptrace: za-ptrace.c
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$(OUTPUT)/za-test: za-test.S $(OUTPUT)/asm-utils.o
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$(CC) -nostdlib $^ -o $@
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$(OUTPUT)/zt-ptrace: zt-ptrace.c
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$(OUTPUT)/zt-test: zt-test.S $(OUTPUT)/asm-utils.o
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$(CC) -nostdlib $^ -o $@
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‎tools/testing/selftests/arm64/fp/zt-ptrace.c‎

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@@ -0,0 +1,365 @@
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2021 ARM Limited.
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*/
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#include <errno.h>
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#include <stdbool.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/auxv.h>
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#include <sys/prctl.h>
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#include <sys/ptrace.h>
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#include <sys/types.h>
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#include <sys/uio.h>
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#include <sys/wait.h>
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#include <asm/sigcontext.h>
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#include <asm/ptrace.h>
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#include "../../kselftest.h"
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/* <linux/elf.h> and <sys/auxv.h> don't like each other, so: */
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#ifndef NT_ARM_ZA
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#define NT_ARM_ZA 0x40c
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#endif
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#ifndef NT_ARM_ZT
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#define NT_ARM_ZT 0x40d
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#endif
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#define EXPECTED_TESTS 3
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static int sme_vl;
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static void fill_buf(char *buf, size_t size)
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{
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int i;
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for (i = 0; i < size; i++)
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buf[i] = random();
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}
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static int do_child(void)
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{
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if (ptrace(PTRACE_TRACEME, -1, NULL, NULL))
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ksft_exit_fail_msg("PTRACE_TRACEME", strerror(errno));
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if (raise(SIGSTOP))
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ksft_exit_fail_msg("raise(SIGSTOP)", strerror(errno));
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return EXIT_SUCCESS;
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}
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static struct user_za_header *get_za(pid_t pid, void **buf, size_t *size)
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{
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struct user_za_header *za;
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void *p;
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size_t sz = sizeof(*za);
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struct iovec iov;
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while (1) {
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if (*size < sz) {
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p = realloc(*buf, sz);
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if (!p) {
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errno = ENOMEM;
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goto error;
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}
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*buf = p;
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*size = sz;
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}
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iov.iov_base = *buf;
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iov.iov_len = sz;
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if (ptrace(PTRACE_GETREGSET, pid, NT_ARM_ZA, &iov))
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goto error;
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za = *buf;
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if (za->size <= sz)
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break;
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sz = za->size;
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}
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return za;
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error:
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return NULL;
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}
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static int set_za(pid_t pid, const struct user_za_header *za)
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{
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struct iovec iov;
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iov.iov_base = (void *)za;
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iov.iov_len = za->size;
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return ptrace(PTRACE_SETREGSET, pid, NT_ARM_ZA, &iov);
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}
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static int get_zt(pid_t pid, char zt[ZT_SIG_REG_BYTES])
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{
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struct iovec iov;
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iov.iov_base = zt;
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iov.iov_len = ZT_SIG_REG_BYTES;
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return ptrace(PTRACE_GETREGSET, pid, NT_ARM_ZT, &iov);
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}
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static int set_zt(pid_t pid, const char zt[ZT_SIG_REG_BYTES])
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{
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struct iovec iov;
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iov.iov_base = (void *)zt;
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iov.iov_len = ZT_SIG_REG_BYTES;
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return ptrace(PTRACE_SETREGSET, pid, NT_ARM_ZT, &iov);
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}
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/* Reading with ZA disabled returns all zeros */
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static void ptrace_za_disabled_read_zt(pid_t child)
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{
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struct user_za_header za;
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char zt[ZT_SIG_REG_BYTES];
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int ret, i;
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bool fail = false;
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/* Disable PSTATE.ZA using the ZA interface */
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memset(&za, 0, sizeof(za));
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za.vl = sme_vl;
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za.size = sizeof(za);
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ret = set_za(child, &za);
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if (ret != 0) {
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ksft_print_msg("Failed to disable ZA\n");
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fail = true;
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}
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/* Read back ZT */
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ret = get_zt(child, zt);
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if (ret != 0) {
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ksft_print_msg("Failed to read ZT\n");
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fail = true;
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}
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for (i = 0; i < ARRAY_SIZE(zt); i++) {
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if (zt[i]) {
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ksft_print_msg("zt[%d]: 0x%x != 0\n", i, zt[i]);
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fail = true;
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}
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}
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ksft_test_result(!fail, "ptrace_za_disabled_read_zt\n");
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}
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/* Writing then reading ZT should return the data written */
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static void ptrace_set_get_zt(pid_t child)
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{
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char zt_in[ZT_SIG_REG_BYTES];
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char zt_out[ZT_SIG_REG_BYTES];
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int ret, i;
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bool fail = false;
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fill_buf(zt_in, sizeof(zt_in));
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ret = set_zt(child, zt_in);
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if (ret != 0) {
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ksft_print_msg("Failed to set ZT\n");
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fail = true;
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}
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ret = get_zt(child, zt_out);
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if (ret != 0) {
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ksft_print_msg("Failed to read ZT\n");
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fail = true;
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}
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for (i = 0; i < ARRAY_SIZE(zt_in); i++) {
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if (zt_in[i] != zt_out[i]) {
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ksft_print_msg("zt[%d]: 0x%x != 0x%x\n", i,
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zt_in[i], zt_out[i]);
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fail = true;
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}
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}
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ksft_test_result(!fail, "ptrace_set_get_zt\n");
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}
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/* Writing ZT should set PSTATE.ZA */
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static void ptrace_enable_za_via_zt(pid_t child)
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{
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struct user_za_header za_in;
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struct user_za_header *za_out;
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char zt[ZT_SIG_REG_BYTES];
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char *za_data;
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size_t za_out_size;
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int ret, i, vq;
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bool fail = false;
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/* Disable PSTATE.ZA using the ZA interface */
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memset(&za_in, 0, sizeof(za_in));
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za_in.vl = sme_vl;
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za_in.size = sizeof(za_in);
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ret = set_za(child, &za_in);
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if (ret != 0) {
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ksft_print_msg("Failed to disable ZA\n");
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fail = true;
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}
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/* Write ZT */
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fill_buf(zt, sizeof(zt));
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ret = set_zt(child, zt);
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if (ret != 0) {
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ksft_print_msg("Failed to set ZT\n");
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fail = true;
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}
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/* Read back ZA and check for register data */
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za_out = NULL;
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za_out_size = 0;
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if (get_za(child, (void **)&za_out, &za_out_size)) {
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/* Should have an unchanged VL */
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if (za_out->vl != sme_vl) {
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ksft_print_msg("VL changed from %d to %d\n",
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sme_vl, za_out->vl);
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fail = true;
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}
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vq = __sve_vq_from_vl(za_out->vl);
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za_data = (char *)za_out + ZA_PT_ZA_OFFSET;
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/* Should have register data */
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if (za_out->size < ZA_PT_SIZE(vq)) {
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ksft_print_msg("ZA data less than expected: %u < %u\n",
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za_out->size, ZA_PT_SIZE(vq));
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fail = true;
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vq = 0;
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}
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/* That register data should be non-zero */
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for (i = 0; i < ZA_PT_ZA_SIZE(vq); i++) {
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if (za_data[i]) {
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ksft_print_msg("ZA byte %d is %x\n",
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i, za_data[i]);
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fail = true;
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}
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}
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} else {
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ksft_print_msg("Failed to read ZA\n");
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fail = true;
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}
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ksft_test_result(!fail, "ptrace_enable_za_via_zt\n");
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}
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static int do_parent(pid_t child)
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{
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int ret = EXIT_FAILURE;
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pid_t pid;
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int status;
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siginfo_t si;
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/* Attach to the child */
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while (1) {
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int sig;
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pid = wait(&status);
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if (pid == -1) {
268+
perror("wait");
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goto error;
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}
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/*
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* This should never happen but it's hard to flag in
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* the framework.
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*/
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if (pid != child)
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continue;
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if (WIFEXITED(status) || WIFSIGNALED(status))
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ksft_exit_fail_msg("Child died unexpectedly\n");
281+
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if (!WIFSTOPPED(status))
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goto error;
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sig = WSTOPSIG(status);
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if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &si)) {
288+
if (errno == ESRCH)
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goto disappeared;
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if (errno == EINVAL) {
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sig = 0; /* bust group-stop */
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goto cont;
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}
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296+
ksft_test_result_fail("PTRACE_GETSIGINFO: %s\n",
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strerror(errno));
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goto error;
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}
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if (sig == SIGSTOP && si.si_code == SI_TKILL &&
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si.si_pid == pid)
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break;
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cont:
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if (ptrace(PTRACE_CONT, pid, NULL, sig)) {
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if (errno == ESRCH)
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goto disappeared;
309+
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ksft_test_result_fail("PTRACE_CONT: %s\n",
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strerror(errno));
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goto error;
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}
314+
}
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316+
ksft_print_msg("Parent is %d, child is %d\n", getpid(), child);
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318+
ptrace_za_disabled_read_zt(child);
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ptrace_set_get_zt(child);
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ptrace_enable_za_via_zt(child);
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ret = EXIT_SUCCESS;
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error:
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kill(child, SIGKILL);
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disappeared:
328+
return ret;
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}
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int main(void)
332+
{
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int ret = EXIT_SUCCESS;
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pid_t child;
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336+
srandom(getpid());
337+
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ksft_print_header();
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if (!(getauxval(AT_HWCAP2) & HWCAP2_SME2)) {
341+
ksft_set_plan(1);
342+
ksft_exit_skip("SME2 not available\n");
343+
}
344+
345+
/* We need a valid SME VL to enable/disable ZA */
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sme_vl = prctl(PR_SME_GET_VL);
347+
if (sme_vl == -1) {
348+
ksft_set_plan(1);
349+
ksft_exit_skip("Failed to read SME VL: %d (%s)\n",
350+
errno, strerror(errno));
351+
}
352+
353+
ksft_set_plan(EXPECTED_TESTS);
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child = fork();
356+
if (!child)
357+
return do_child();
358+
359+
if (do_parent(child))
360+
ret = EXIT_FAILURE;
361+
362+
ksft_print_cnts();
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return ret;
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}

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