// 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 <[email protected]>
*
*
* 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 <errno.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;
struct child_args {
int num_threads;
int pfd[2];
int cpid;
int thr_tids[MAX_THREADS];
};
static struct child_args procs[MAX_PROCESSES];
static int num_processes = 2;
static int need_cleanup;
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)
{
int pidx;
printf("(%s:%d) - ", fn, ln);
perror(msg);
if (need_cleanup) {
for (pidx = 0; pidx < num_processes; ++pidx)
kill(procs[pidx].cpid, 15);
need_cleanup = 0;
}
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;
}
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;
int ret;
close(ca->pfd[0]);
create_threads(ca->num_threads, ca->thr_tids);
ret = write(ca->pfd[1], &ca->thr_tids, sizeof(int) * ca->num_threads);
if (ret == -1)
printf("write failed on pfd[%d] - error (%s)\n",
ca->pfd[1], strerror(errno));
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, ret;
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) {
ret = read(proc[i].pfd[0], &proc[i].thr_tids, sizeof(int) * proc[i].num_threads);
if (ret == -1)
printf("read failed on proc[%d].pfd[0] error (%s)\n",
i, strerror(errno));
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[])
{
int keypress = 0;
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 hierarchy\n");
create_processes(num_processes, num_threads, procs);
need_cleanup = 1;
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]));
validate(_prctl(PR_SCHED_CORE, PR_SCHED_CORE_MAX, 0, PIDTYPE_PGID, 0) < 0
&& errno == EINVAL);
validate(_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, 0, PIDTYPE_PGID, 1) < 0
&& errno == EINVAL);
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;
}
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