Commit ecaf4d3f authored by Mark Brown's avatar Mark Brown Committed by Catalin Marinas
Browse files

kselftest/arm64: Add test coverage for NT_ARM_TLS 



In preparation for extending support for NT_ARM_TLS to cover additional
TPIDRs add some tests for the existing interface. Do this in a generic
ptrace test program to provide a place to collect additional tests in
the future.

Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220829154921.837871-2-broonie@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent b90cb105

tools/testing/selftests/arm64/abi/.gitignore

+1 −0
Original line number Diff line number Diff line 
ptrace

syscall-abi

tpidr2

tools/testing/selftests/arm64/abi/Makefile

+1 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

# Copyright (C) 2021 ARM Limited



TEST_GEN_PROGS := syscall-abi tpidr2

TEST_GEN_PROGS := ptrace syscall-abi tpidr2



include ../../lib.mk

tools/testing/selftests/arm64/abi/ptrace.c

0 → 100644
+165 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2022 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"



#define EXPECTED_TESTS 3



#define MAX_TPIDRS 1



static bool have_sme(void)

{

	return getauxval(AT_HWCAP2) & HWCAP2_SME;

}



static void test_tpidr(pid_t child)

{

	uint64_t read_val[MAX_TPIDRS];

	uint64_t write_val[MAX_TPIDRS];

	struct iovec read_iov, write_iov;

	int ret;



	read_iov.iov_base = read_val;

	write_iov.iov_base = write_val;



	/* Should be able to read a single TPIDR... */

	read_iov.iov_len = sizeof(uint64_t);

	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);

	ksft_test_result(ret == 0, "read_tpidr_one\n");



	/* ...write a new value.. */

	write_iov.iov_len = sizeof(uint64_t);

	write_val[0] = read_val[0]++;

	ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);

	ksft_test_result(ret == 0, "write_tpidr_one\n");



	/* ...then read it back */

	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);

	ksft_test_result(ret == 0 && write_val[0] == read_val[0],

			 "verify_tpidr_one\n");

}



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 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);



	test_tpidr(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();



	ksft_set_plan(EXPECTED_TESTS);



	child = fork();

	if (!child)

		return do_child();



	if (do_parent(child))

		ret = EXIT_FAILURE;



	ksft_print_cnts();



	return ret;

}