linux-zen-desktop/tools/testing/selftests/arm64/fp/zt-ptrace.c

366 lines
6.9 KiB
C

// 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;
}