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#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <sys/wait.h>
static const struct sockaddr sa;
int main(int argc, char *argv[])
{
int loops;
int pid;
sigset_t set;
printf(
"Please run me under 'strace -f -oLOG', and examine LOG file for incorrect\n"
"decoding of interrupted syscalls: grep for 'sendto', '??" /* anti-trigraph gap */ "?', 'unavailable'.\n"
"Pass number of iterations in argv[1] (default: 999).\n"
);
fflush(NULL);
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigprocmask(SIG_BLOCK, &set, NULL);
loops = 999;
if (argv[1])
loops = atoi(argv[1]);
while (--loops >= 0) {
pid = fork();
if (pid < 0)
exit(1);
if (!pid) {
/* child */
int child = getpid();
loops = 99;
while (--loops) {
pid = fork();
if (pid < 0)
exit(1);
if (!pid) {
/* grandchild: kill child */
kill(child, SIGKILL);
exit(0);
}
/* Add various syscalls you want to test here.
* strace will decode them and suddenly find
* process disappearing.
* But leave at least one case "empty", so that
* "kill grandchild" happens quicker.
* This produces cases when strace can't even
* decode syscall number before process dies.
*/
switch (loops & 1) {
case 0:
break; /* intentionally empty */
case 1:
sendto(-1, "Hello cruel world", 17, 0, &sa, sizeof(sa));
break;
}
/* kill grandchild */
kill(pid, SIGKILL);
}
exit(0);
}
/* parent */
wait(NULL);
}
return 0;
}
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