selftests: breakpoint: add step_after_suspend_test

Commit e56d82a116 ("arm64: cpu hotplug: ensure we mask out
CPU_TASKS_FROZEN in notifiers") fixed a long-standing ARM64 bug that
broke single-stepping after a suspend/resume cycle.  Add a kernel
selftest to make sure this doesn't regress or affect other platforms.

Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
This commit is contained in:
Greg Hackmann 2016-02-22 10:10:57 -08:00 committed by Shuah Khan
parent 9d22f6e14e
commit bfd092b8c2
2 changed files with 221 additions and 1 deletions

View File

@ -6,9 +6,11 @@ ifeq ($(ARCH),x86)
TEST_PROGS := breakpoint_test
endif
TEST_PROGS += step_after_suspend_test
all: $(TEST_PROGS)
include ../lib.mk
clean:
rm -fr breakpoint_test
rm -fr breakpoint_test step_after_suspend_test

View File

@ -0,0 +1,218 @@
/*
* Copyright (C) 2016 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/ptrace.h>
#include <sys/stat.h>
#include <sys/timerfd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include "../kselftest.h"
void child(int cpu)
{
cpu_set_t set;
CPU_ZERO(&set);
CPU_SET(cpu, &set);
if (sched_setaffinity(0, sizeof(set), &set) != 0) {
perror("sched_setaffinity() failed");
_exit(1);
}
if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {
perror("ptrace(PTRACE_TRACEME) failed");
_exit(1);
}
if (raise(SIGSTOP) != 0) {
perror("raise(SIGSTOP) failed");
_exit(1);
}
_exit(0);
}
bool run_test(int cpu)
{
int status;
pid_t pid = fork();
pid_t wpid;
if (pid < 0) {
perror("fork() failed");
return false;
}
if (pid == 0)
child(cpu);
wpid = waitpid(pid, &status, __WALL);
if (wpid != pid) {
perror("waitpid() failed");
return false;
}
if (!WIFSTOPPED(status)) {
printf("child did not stop\n");
return false;
}
if (WSTOPSIG(status) != SIGSTOP) {
printf("child did not stop with SIGSTOP\n");
return false;
}
if (ptrace(PTRACE_SINGLESTEP, pid, NULL, NULL) < 0) {
if (errno == EIO) {
printf("ptrace(PTRACE_SINGLESTEP) not supported on this architecture\n");
ksft_exit_skip();
}
perror("ptrace(PTRACE_SINGLESTEP) failed");
return false;
}
wpid = waitpid(pid, &status, __WALL);
if (wpid != pid) {
perror("waitpid() failed");
return false;
}
if (WIFEXITED(status)) {
printf("child did not single-step\n");
return false;
}
if (!WIFSTOPPED(status)) {
printf("child did not stop\n");
return false;
}
if (WSTOPSIG(status) != SIGTRAP) {
printf("child did not stop with SIGTRAP\n");
return false;
}
if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
perror("ptrace(PTRACE_CONT) failed");
return false;
}
wpid = waitpid(pid, &status, __WALL);
if (wpid != pid) {
perror("waitpid() failed");
return false;
}
if (!WIFEXITED(status)) {
printf("child did not exit after PTRACE_CONT\n");
return false;
}
return true;
}
void suspend(void)
{
int power_state_fd;
struct sigevent event = {};
int timerfd;
int err;
struct itimerspec spec = {};
power_state_fd = open("/sys/power/state", O_RDWR);
if (power_state_fd < 0) {
perror("open(\"/sys/power/state\") failed (is this test running as root?)");
ksft_exit_fail();
}
timerfd = timerfd_create(CLOCK_BOOTTIME_ALARM, 0);
if (timerfd < 0) {
perror("timerfd_create() failed");
ksft_exit_fail();
}
spec.it_value.tv_sec = 5;
err = timerfd_settime(timerfd, 0, &spec, NULL);
if (err < 0) {
perror("timerfd_settime() failed");
ksft_exit_fail();
}
if (write(power_state_fd, "mem", strlen("mem")) != strlen("mem")) {
perror("entering suspend failed");
ksft_exit_fail();
}
close(timerfd);
close(power_state_fd);
}
int main(int argc, char **argv)
{
int opt;
bool do_suspend = true;
bool succeeded = true;
cpu_set_t available_cpus;
int err;
int cpu;
while ((opt = getopt(argc, argv, "n")) != -1) {
switch (opt) {
case 'n':
do_suspend = false;
break;
default:
printf("Usage: %s [-n]\n", argv[0]);
printf(" -n: do not trigger a suspend/resume cycle before the test\n");
return -1;
}
}
if (do_suspend)
suspend();
err = sched_getaffinity(0, sizeof(available_cpus), &available_cpus);
if (err < 0) {
perror("sched_getaffinity() failed");
ksft_exit_fail();
}
for (cpu = 0; cpu < CPU_SETSIZE; cpu++) {
bool test_success;
if (!CPU_ISSET(cpu, &available_cpus))
continue;
test_success = run_test(cpu);
printf("CPU %d: ", cpu);
if (test_success) {
printf("[OK]\n");
ksft_inc_pass_cnt();
} else {
printf("[FAILED]\n");
ksft_inc_fail_cnt();
succeeded = false;
}
}
ksft_print_cnts();
if (succeeded)
ksft_exit_pass();
else
ksft_exit_fail();
}