Add coverage of the ZT ptrace interface.
Signed-off-by: Mark Brown broonie@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(+) create mode 100644 tools/testing/selftests/arm64/fp/zt-ptrace.c
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; +}