Commit e56d82a11617 ("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@xxxxxxxxxx> --- tools/testing/selftests/breakpoints/Makefile | 4 +- .../breakpoints/step_after_suspend_test.c | 219 +++++++++++++++++++++ 2 files changed, 222 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/breakpoints/step_after_suspend_test.c diff --git a/tools/testing/selftests/breakpoints/Makefile b/tools/testing/selftests/breakpoints/Makefile index c0d9570..74e533f 100644 --- a/tools/testing/selftests/breakpoints/Makefile +++ b/tools/testing/selftests/breakpoints/Makefile @@ -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 diff --git a/tools/testing/selftests/breakpoints/step_after_suspend_test.c b/tools/testing/selftests/breakpoints/step_after_suspend_test.c new file mode 100644 index 0000000..93dfdec --- /dev/null +++ b/tools/testing/selftests/breakpoints/step_after_suspend_test.c @@ -0,0 +1,219 @@ +/* + * 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(); +} + -- 2.7.0.rc3.207.g0ac5344 -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html