tools/testing/selftests/arm64/fp/za-ptrace.c - linux/torvalds/linux - Git at Google

 // 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

 #define EXPECTED_TESTS (((SVE_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 <= SVE_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;
 }
	// 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

	#define EXPECTED_TESTS (((SVE_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 <= SVE_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;
	}