/*
 * glibc 2.3.2 signal race example
 *
 * Simon Kirby <sim@netnation.com>, 2003/08/21
 *
 * Compile with the following:
 *
 *         gcc -o signal-crash-example signal-crash-example.c -lpthread
 *
 * This should cause a Segmentation fault shortly in a second or so when
 * used on glibc 2.3.2 (2.3.1 and before are unaffected).  NTPL-enabled
 * kernels (eg: Red Hat 9.0 kernels) are also unaffected.  This program
 * must be compiled with libpthread to show the problem.
 */

#include <sys/types.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>

void signalhandler(int sig)
{
}

int main(int argc, char *argv[])
{
	pid_t pid;
	int i;

	while (1) {
		for (i = 0; i < 100; i++){
			if ((pid = fork()) == -1) {
				perror("Fork error");
				exit(1);
			}
			if (pid == 0) {
				usleep(100000);
				signal(SIGCHLD, SIG_DFL);
				exit(0);
			}
		}
		usleep(100000);
		for (i = 0; i < 10000; i++){
			signal(SIGCHLD, SIG_DFL);
			signal(SIGCHLD, signalhandler);
			signal(SIGCHLD, SIG_DFL);
			signal(SIGCHLD, signalhandler);
		}
		while (wait(NULL) != -1)
			;
	}
}