| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Use the core scheduling prctl() to test core scheduling cookies control. |
| * |
| * Copyright (c) 2021 Oracle and/or its affiliates. |
| * Author: Chris Hyser <chris.hyser@oracle.com> |
| * |
| * |
| * This library is free software; you can redistribute it and/or modify it |
| * under the terms of version 2.1 of the GNU Lesser General Public License as |
| * published by the Free Software Foundation. |
| * |
| * This library 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 Lesser General Public License |
| * for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public License |
| * along with this library; if not, see <http://www.gnu.org/licenses>. |
| */ |
| |
| #define _GNU_SOURCE |
| #include <sys/eventfd.h> |
| #include <sys/wait.h> |
| #include <sys/types.h> |
| #include <sched.h> |
| #include <sys/prctl.h> |
| #include <unistd.h> |
| #include <time.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #if __GLIBC_PREREQ(2, 30) == 0 |
| #include <sys/syscall.h> |
| static pid_t gettid(void) |
| { |
| return syscall(SYS_gettid); |
| } |
| #endif |
| |
| #ifndef PR_SCHED_CORE |
| #define PR_SCHED_CORE 62 |
| # define PR_SCHED_CORE_GET 0 |
| # define PR_SCHED_CORE_CREATE 1 /* create unique core_sched cookie */ |
| # define PR_SCHED_CORE_SHARE_TO 2 /* push core_sched cookie to pid */ |
| # define PR_SCHED_CORE_SHARE_FROM 3 /* pull core_sched cookie to pid */ |
| # define PR_SCHED_CORE_MAX 4 |
| #endif |
| |
| #define MAX_PROCESSES 128 |
| #define MAX_THREADS 128 |
| |
| static const char USAGE[] = "cs_prctl_test [options]\n" |
| " options:\n" |
| " -P : number of processes to create.\n" |
| " -T : number of threads per process to create.\n" |
| " -d : delay time to keep tasks alive.\n" |
| " -k : keep tasks alive until keypress.\n"; |
| |
| enum pid_type {PIDTYPE_PID = 0, PIDTYPE_TGID, PIDTYPE_PGID}; |
| |
| const int THREAD_CLONE_FLAGS = CLONE_THREAD | CLONE_SIGHAND | CLONE_FS | CLONE_VM | CLONE_FILES; |
| |
| static int _prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, |
| unsigned long arg5) |
| { |
| int res; |
| |
| res = prctl(option, arg2, arg3, arg4, arg5); |
| printf("%d = prctl(%d, %ld, %ld, %ld, %lx)\n", res, option, (long)arg2, (long)arg3, |
| (long)arg4, arg5); |
| return res; |
| } |
| |
| #define STACK_SIZE (1024 * 1024) |
| |
| #define handle_error(msg) __handle_error(__FILE__, __LINE__, msg) |
| static void __handle_error(char *fn, int ln, char *msg) |
| { |
| printf("(%s:%d) - ", fn, ln); |
| perror(msg); |
| exit(EXIT_FAILURE); |
| } |
| |
| static void handle_usage(int rc, char *msg) |
| { |
| puts(USAGE); |
| puts(msg); |
| putchar('\n'); |
| exit(rc); |
| } |
| |
| static unsigned long get_cs_cookie(int pid) |
| { |
| unsigned long long cookie; |
| int ret; |
| |
| ret = prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, pid, PIDTYPE_PID, |
| (unsigned long)&cookie); |
| if (ret) { |
| printf("Not a core sched system\n"); |
| return -1UL; |
| } |
| |
| return cookie; |
| } |
| |
| struct child_args { |
| int num_threads; |
| int pfd[2]; |
| int cpid; |
| int thr_tids[MAX_THREADS]; |
| }; |
| |
| static int child_func_thread(void __attribute__((unused))*arg) |
| { |
| while (1) |
| usleep(20000); |
| return 0; |
| } |
| |
| static void create_threads(int num_threads, int thr_tids[]) |
| { |
| void *child_stack; |
| pid_t tid; |
| int i; |
| |
| for (i = 0; i < num_threads; ++i) { |
| child_stack = malloc(STACK_SIZE); |
| if (!child_stack) |
| handle_error("child stack allocate"); |
| |
| tid = clone(child_func_thread, child_stack + STACK_SIZE, THREAD_CLONE_FLAGS, NULL); |
| if (tid == -1) |
| handle_error("clone thread"); |
| thr_tids[i] = tid; |
| } |
| } |
| |
| static int child_func_process(void *arg) |
| { |
| struct child_args *ca = (struct child_args *)arg; |
| |
| close(ca->pfd[0]); |
| |
| create_threads(ca->num_threads, ca->thr_tids); |
| |
| write(ca->pfd[1], &ca->thr_tids, sizeof(int) * ca->num_threads); |
| close(ca->pfd[1]); |
| |
| while (1) |
| usleep(20000); |
| return 0; |
| } |
| |
| static unsigned char child_func_process_stack[STACK_SIZE]; |
| |
| void create_processes(int num_processes, int num_threads, struct child_args proc[]) |
| { |
| pid_t cpid; |
| int i; |
| |
| for (i = 0; i < num_processes; ++i) { |
| proc[i].num_threads = num_threads; |
| |
| if (pipe(proc[i].pfd) == -1) |
| handle_error("pipe() failed"); |
| |
| cpid = clone(child_func_process, child_func_process_stack + STACK_SIZE, |
| SIGCHLD, &proc[i]); |
| proc[i].cpid = cpid; |
| close(proc[i].pfd[1]); |
| } |
| |
| for (i = 0; i < num_processes; ++i) { |
| read(proc[i].pfd[0], &proc[i].thr_tids, sizeof(int) * proc[i].num_threads); |
| close(proc[i].pfd[0]); |
| } |
| } |
| |
| void disp_processes(int num_processes, struct child_args proc[]) |
| { |
| int i, j; |
| |
| printf("tid=%d, / tgid=%d / pgid=%d: %lx\n", gettid(), getpid(), getpgid(0), |
| get_cs_cookie(getpid())); |
| |
| for (i = 0; i < num_processes; ++i) { |
| printf(" tid=%d, / tgid=%d / pgid=%d: %lx\n", proc[i].cpid, proc[i].cpid, |
| getpgid(proc[i].cpid), get_cs_cookie(proc[i].cpid)); |
| for (j = 0; j < proc[i].num_threads; ++j) { |
| printf(" tid=%d, / tgid=%d / pgid=%d: %lx\n", proc[i].thr_tids[j], |
| proc[i].cpid, getpgid(0), get_cs_cookie(proc[i].thr_tids[j])); |
| } |
| } |
| puts("\n"); |
| } |
| |
| static int errors; |
| |
| #define validate(v) _validate(__LINE__, v, #v) |
| void _validate(int line, int val, char *msg) |
| { |
| if (!val) { |
| ++errors; |
| printf("(%d) FAILED: %s\n", line, msg); |
| } else { |
| printf("(%d) PASSED: %s\n", line, msg); |
| } |
| } |
| |
| int main(int argc, char *argv[]) |
| { |
| struct child_args procs[MAX_PROCESSES]; |
| |
| int keypress = 0; |
| int num_processes = 2; |
| int num_threads = 3; |
| int delay = 0; |
| int res = 0; |
| int pidx; |
| int pid; |
| int opt; |
| |
| while ((opt = getopt(argc, argv, ":hkT:P:d:")) != -1) { |
| switch (opt) { |
| case 'P': |
| num_processes = (int)strtol(optarg, NULL, 10); |
| break; |
| case 'T': |
| num_threads = (int)strtoul(optarg, NULL, 10); |
| break; |
| case 'd': |
| delay = (int)strtol(optarg, NULL, 10); |
| break; |
| case 'k': |
| keypress = 1; |
| break; |
| case 'h': |
| printf(USAGE); |
| exit(EXIT_SUCCESS); |
| default: |
| handle_usage(20, "unknown option"); |
| } |
| } |
| |
| if (num_processes < 1 || num_processes > MAX_PROCESSES) |
| handle_usage(1, "Bad processes value"); |
| |
| if (num_threads < 1 || num_threads > MAX_THREADS) |
| handle_usage(2, "Bad thread value"); |
| |
| if (keypress) |
| delay = -1; |
| |
| srand(time(NULL)); |
| |
| /* put into separate process group */ |
| if (setpgid(0, 0) != 0) |
| handle_error("process group"); |
| |
| printf("\n## Create a thread/process/process group hiearchy\n"); |
| create_processes(num_processes, num_threads, procs); |
| disp_processes(num_processes, procs); |
| validate(get_cs_cookie(0) == 0); |
| |
| printf("\n## Set a cookie on entire process group\n"); |
| if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, 0, PIDTYPE_PGID, 0) < 0) |
| handle_error("core_sched create failed -- PGID"); |
| disp_processes(num_processes, procs); |
| |
| validate(get_cs_cookie(0) != 0); |
| |
| /* get a random process pid */ |
| pidx = rand() % num_processes; |
| pid = procs[pidx].cpid; |
| |
| validate(get_cs_cookie(0) == get_cs_cookie(pid)); |
| validate(get_cs_cookie(0) == get_cs_cookie(procs[pidx].thr_tids[0])); |
| |
| printf("\n## Set a new cookie on entire process/TGID [%d]\n", pid); |
| if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, pid, PIDTYPE_TGID, 0) < 0) |
| handle_error("core_sched create failed -- TGID"); |
| disp_processes(num_processes, procs); |
| |
| validate(get_cs_cookie(0) != get_cs_cookie(pid)); |
| validate(get_cs_cookie(pid) != 0); |
| validate(get_cs_cookie(pid) == get_cs_cookie(procs[pidx].thr_tids[0])); |
| |
| printf("\n## Copy the cookie of current/PGID[%d], to pid [%d] as PIDTYPE_PID\n", |
| getpid(), pid); |
| if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, pid, PIDTYPE_PID, 0) < 0) |
| handle_error("core_sched share to itself failed -- PID"); |
| disp_processes(num_processes, procs); |
| |
| validate(get_cs_cookie(0) == get_cs_cookie(pid)); |
| validate(get_cs_cookie(pid) != 0); |
| validate(get_cs_cookie(pid) != get_cs_cookie(procs[pidx].thr_tids[0])); |
| |
| printf("\n## Copy cookie from a thread [%d] to current/PGID [%d] as PIDTYPE_PID\n", |
| procs[pidx].thr_tids[0], getpid()); |
| if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, procs[pidx].thr_tids[0], |
| PIDTYPE_PID, 0) < 0) |
| handle_error("core_sched share from thread failed -- PID"); |
| disp_processes(num_processes, procs); |
| |
| validate(get_cs_cookie(0) == get_cs_cookie(procs[pidx].thr_tids[0])); |
| validate(get_cs_cookie(pid) != get_cs_cookie(procs[pidx].thr_tids[0])); |
| |
| printf("\n## Copy cookie from current [%d] to current as pidtype PGID\n", getpid()); |
| if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, 0, PIDTYPE_PGID, 0) < 0) |
| handle_error("core_sched share to self failed -- PGID"); |
| disp_processes(num_processes, procs); |
| |
| validate(get_cs_cookie(0) == get_cs_cookie(pid)); |
| validate(get_cs_cookie(pid) != 0); |
| validate(get_cs_cookie(pid) == get_cs_cookie(procs[pidx].thr_tids[0])); |
| |
| if (errors) { |
| printf("TESTS FAILED. errors: %d\n", errors); |
| res = 10; |
| } else { |
| printf("SUCCESS !!!\n"); |
| } |
| |
| if (keypress) |
| getchar(); |
| else |
| sleep(delay); |
| |
| for (pidx = 0; pidx < num_processes; ++pidx) |
| kill(procs[pidx].cpid, 15); |
| |
| return res; |
| } |