blob: ac27d87396fc25472f43bc9514160fac508bf47d [file] [log] [blame]
// 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
/*
* The architecture defines the maximum VQ as 16 but for extensibility
* the kernel specifies the SVE_VQ_MAX as 512 resulting in us running
* a *lot* more tests than are useful if we use it. Until the
* architecture is extended let's limit our coverage to what is
* currently allowed, plus one extra to ensure we cover constraining
* the VL as expected.
*/
#define TEST_VQ_MAX 17
#define EXPECTED_TESTS (((TEST_VQ_MAX - SVE_VQ_MIN) + 1) * 3)
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);
}
/* Validate attempting to set the specfied VL via ptrace */
static void ptrace_set_get_vl(pid_t child, unsigned int vl, bool *supported)
{
struct user_za_header za;
struct user_za_header *new_za = NULL;
size_t new_za_size = 0;
int ret, prctl_vl;
*supported = false;
/* Check if the VL is supported in this process */
prctl_vl = prctl(PR_SME_SET_VL, vl);
if (prctl_vl == -1)
ksft_exit_fail_msg("prctl(PR_SME_SET_VL) failed: %s (%d)\n",
strerror(errno), errno);
/* If the VL is not supported then a supported VL will be returned */
*supported = (prctl_vl == vl);
/* Set the VL by doing a set with no register payload */
memset(&za, 0, sizeof(za));
za.size = sizeof(za);
za.vl = vl;
ret = set_za(child, &za);
if (ret != 0) {
ksft_test_result_fail("Failed to set VL %u\n", vl);
return;
}
/*
* Read back the new register state and verify that we have the
* same VL that we got from prctl() on ourselves.
*/
if (!get_za(child, (void **)&new_za, &new_za_size)) {
ksft_test_result_fail("Failed to read VL %u\n", vl);
return;
}
ksft_test_result(new_za->vl = prctl_vl, "Set VL %u\n", vl);
free(new_za);
}
/* Validate attempting to set no ZA data and read it back */
static void ptrace_set_no_data(pid_t child, unsigned int vl)
{
void *read_buf = NULL;
struct user_za_header write_za;
struct user_za_header *read_za;
size_t read_za_size = 0;
int ret;
/* Set up some data and write it out */
memset(&write_za, 0, sizeof(write_za));
write_za.size = ZA_PT_ZA_OFFSET;
write_za.vl = vl;
ret = set_za(child, &write_za);
if (ret != 0) {
ksft_test_result_fail("Failed to set VL %u no data\n", vl);
return;
}
/* Read the data back */
if (!get_za(child, (void **)&read_buf, &read_za_size)) {
ksft_test_result_fail("Failed to read VL %u no data\n", vl);
return;
}
read_za = read_buf;
/* We might read more data if there's extensions we don't know */
if (read_za->size < write_za.size) {
ksft_test_result_fail("VL %u wrote %d bytes, only read %d\n",
vl, write_za.size, read_za->size);
goto out_read;
}
ksft_test_result(read_za->size == write_za.size,
"Disabled ZA for VL %u\n", vl);
out_read:
free(read_buf);
}
/* Validate attempting to set data and read it back */
static void ptrace_set_get_data(pid_t child, unsigned int vl)
{
void *write_buf;
void *read_buf = NULL;
struct user_za_header *write_za;
struct user_za_header *read_za;
size_t read_za_size = 0;
unsigned int vq = sve_vq_from_vl(vl);
int ret;
size_t data_size;
data_size = ZA_PT_SIZE(vq);
write_buf = malloc(data_size);
if (!write_buf) {
ksft_test_result_fail("Error allocating %d byte buffer for VL %u\n",
data_size, vl);
return;
}
write_za = write_buf;
/* Set up some data and write it out */
memset(write_za, 0, data_size);
write_za->size = data_size;
write_za->vl = vl;
fill_buf(write_buf + ZA_PT_ZA_OFFSET, ZA_PT_ZA_SIZE(vq));
ret = set_za(child, write_za);
if (ret != 0) {
ksft_test_result_fail("Failed to set VL %u data\n", vl);
goto out;
}
/* Read the data back */
if (!get_za(child, (void **)&read_buf, &read_za_size)) {
ksft_test_result_fail("Failed to read VL %u data\n", vl);
goto out;
}
read_za = read_buf;
/* We might read more data if there's extensions we don't know */
if (read_za->size < write_za->size) {
ksft_test_result_fail("VL %u wrote %d bytes, only read %d\n",
vl, write_za->size, read_za->size);
goto out_read;
}
ksft_test_result(memcmp(write_buf + ZA_PT_ZA_OFFSET,
read_buf + ZA_PT_ZA_OFFSET,
ZA_PT_ZA_SIZE(vq)) == 0,
"Data match for VL %u\n", vl);
out_read:
free(read_buf);
out:
free(write_buf);
}
static int do_parent(pid_t child)
{
int ret = EXIT_FAILURE;
pid_t pid;
int status;
siginfo_t si;
unsigned int vq, vl;
bool vl_supported;
/* 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);
/* Step through every possible VQ */
for (vq = SVE_VQ_MIN; vq <= TEST_VQ_MAX; vq++) {
vl = sve_vl_from_vq(vq);
/* First, try to set this vector length */
ptrace_set_get_vl(child, vl, &vl_supported);
/* If the VL is supported validate data set/get */
if (vl_supported) {
ptrace_set_no_data(child, vl);
ptrace_set_get_data(child, vl);
} else {
ksft_test_result_skip("Disabled ZA for VL %u\n", vl);
ksft_test_result_skip("Get and set data for VL %u\n",
vl);
}
}
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_SME)) {
ksft_set_plan(1);
ksft_exit_skip("SME not available\n");
}
ksft_set_plan(EXPECTED_TESTS);
child = fork();
if (!child)
return do_child();
if (do_parent(child))
ret = EXIT_FAILURE;
ksft_print_cnts();
return ret;
}