/* * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */// Test that /proc/thread-self gives correct TGID/PID.#undef NDEBUG#include <assert.h>#include <sched.h>#include <stdio.h>#include <unistd.h>#include <sys/mman.h>#include <sys/wait.h> #include "proc.h" int f(void *arg){	char buf1[64], buf2[64];	pid_t pid, tid;	ssize_t rv; 	pid = sys_getpid();	tid = sys_gettid();	snprintf(buf1, sizeof(buf1), "%u/task/%u", pid, tid); 	rv = readlink("/proc/thread-self", buf2, sizeof(buf2));	assert(rv == strlen(buf1));	buf2[rv] = '\0';	assert(streq(buf1, buf2)); 	if (arg)		exit(0);	return 0;} int main(void){	const int PAGE_SIZE = sysconf(_SC_PAGESIZE);	pid_t pid;	void *stack; 	/* main thread */	f((void *)0); 	stack = mmap(NULL, 2 * PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);	assert(stack != MAP_FAILED);	/* side thread */	pid = clone(f, stack + PAGE_SIZE, CLONE_THREAD|CLONE_SIGHAND|CLONE_VM, (void *)1);	assert(pid > 0);	pause(); 	return 0;}