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https://github.com/moby/moby.git
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54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
#define _GNU_SOURCE
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#include <sched.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <sys/wait.h>
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#include <signal.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <string.h>
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#include <limits.h>
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#include <errno.h>
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#define STACKSIZE (1024*1024)
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static char child_stack[STACKSIZE];
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struct clone_args {
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char **argv;
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};
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// child_exec is the func that will be executed as the result of clone
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static int child_exec(void *stuff)
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{
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struct clone_args *args = (struct clone_args *)stuff;
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if (execvp(args->argv[0], args->argv) != 0) {
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fprintf(stderr, "failed to execvp argments %s\n",
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strerror(errno));
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exit(-1);
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}
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// we should never reach here!
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exit(EXIT_FAILURE);
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}
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int main(int argc, char **argv)
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{
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struct clone_args args;
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args.argv = &argv[1];
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int clone_flags = CLONE_NEWUSER | SIGCHLD;
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// the result of this call is that our child_exec will be run in another
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// process returning it's pid
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pid_t pid =
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clone(child_exec, child_stack + STACKSIZE, clone_flags, &args);
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if (pid < 0) {
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fprintf(stderr, "clone failed: %s\n", strerror(errno));
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exit(EXIT_FAILURE);
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}
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// lets wait on our child process here before we, the parent, exits
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if (waitpid(pid, NULL, 0) == -1) {
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fprintf(stderr, "failed to wait pid %d\n", pid);
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exit(EXIT_FAILURE);
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}
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exit(EXIT_SUCCESS);
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}
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