1 76193d7c 2003-09-30 devnull #include <fcntl.h>
  2 76193d7c 2003-09-30 devnull #include <unistd.h>
  3 76193d7c 2003-09-30 devnull #include "threadimpl.h"
  4 76193d7c 2003-09-30 devnull 
  5 76193d7c 2003-09-30 devnull void
  6 76193d7c 2003-09-30 devnull procexec(Channel *pidc, char *prog, char *args[])
  7 76193d7c 2003-09-30 devnull {
  8 76193d7c 2003-09-30 devnull 	int n;
  9 76193d7c 2003-09-30 devnull 	Proc *p;
 10 76193d7c 2003-09-30 devnull 	Thread *t;
 11 76193d7c 2003-09-30 devnull 
 12 76193d7c 2003-09-30 devnull 	_threaddebug(DBGEXEC, "procexec %s", prog);
 13 76193d7c 2003-09-30 devnull 	/* must be only thread in proc */
 14 76193d7c 2003-09-30 devnull 	p = _threadgetproc();
 15 76193d7c 2003-09-30 devnull 	t = p->thread;
 16 76193d7c 2003-09-30 devnull 	if(p->threads.head != t || p->threads.head->nextt != nil){
 17 76193d7c 2003-09-30 devnull 		werrstr("not only thread in proc");
 18 76193d7c 2003-09-30 devnull 	Bad:
 19 76193d7c 2003-09-30 devnull 		if(pidc)
 20 76193d7c 2003-09-30 devnull 			sendul(pidc, ~0);
 21 76193d7c 2003-09-30 devnull 		return;
 22 76193d7c 2003-09-30 devnull 	}
 23 76193d7c 2003-09-30 devnull 
 24 76193d7c 2003-09-30 devnull 	/*
 25 76193d7c 2003-09-30 devnull 	 * We want procexec to behave like exec; if exec succeeds,
 26 76193d7c 2003-09-30 devnull 	 * never return, and if it fails, return with errstr set.
 27 76193d7c 2003-09-30 devnull 	 * Unfortunately, the exec happens in another proc since
 28 76193d7c 2003-09-30 devnull 	 * we have to wait for the exec'ed process to finish.
 29 76193d7c 2003-09-30 devnull 	 * To provide the semantics, we open a pipe with the 
 30 76193d7c 2003-09-30 devnull 	 * write end close-on-exec and hand it to the proc that
 31 76193d7c 2003-09-30 devnull 	 * is doing the exec.  If the exec succeeds, the pipe will
 32 76193d7c 2003-09-30 devnull 	 * close so that our read below fails.  If the exec fails,
 33 76193d7c 2003-09-30 devnull 	 * then the proc doing the exec sends the errstr down the
 34 76193d7c 2003-09-30 devnull 	 * pipe to us.
 35 76193d7c 2003-09-30 devnull 	 */
 36 76193d7c 2003-09-30 devnull 	if(pipe(p->exec.fd) < 0)
 37 76193d7c 2003-09-30 devnull 		goto Bad;
 38 76193d7c 2003-09-30 devnull 	if(fcntl(p->exec.fd[1], F_SETFD, 1) < 0)
 39 76193d7c 2003-09-30 devnull 		goto Bad;
 40 76193d7c 2003-09-30 devnull 
 41 76193d7c 2003-09-30 devnull 	/* exec in parallel via the scheduler */
 42 76193d7c 2003-09-30 devnull 	assert(p->needexec==0);
 43 76193d7c 2003-09-30 devnull 	p->exec.prog = prog;
 44 76193d7c 2003-09-30 devnull 	p->exec.args = args;
 45 76193d7c 2003-09-30 devnull 	p->needexec = 1;
 46 76193d7c 2003-09-30 devnull 	_sched();
 47 76193d7c 2003-09-30 devnull 
 48 76193d7c 2003-09-30 devnull 	close(p->exec.fd[1]);
 49 76193d7c 2003-09-30 devnull 	if((n = read(p->exec.fd[0], p->exitstr, ERRMAX-1)) > 0){	/* exec failed */
 50 76193d7c 2003-09-30 devnull 		p->exitstr[n] = '\0';
 51 76193d7c 2003-09-30 devnull 		errstr(p->exitstr, ERRMAX);
 52 76193d7c 2003-09-30 devnull 		close(p->exec.fd[0]);
 53 76193d7c 2003-09-30 devnull 		goto Bad;
 54 76193d7c 2003-09-30 devnull 	}
 55 76193d7c 2003-09-30 devnull 	close(p->exec.fd[0]);
 56 76193d7c 2003-09-30 devnull 
 57 76193d7c 2003-09-30 devnull 	if(pidc)
 58 76193d7c 2003-09-30 devnull 		sendul(pidc, t->ret);
 59 76193d7c 2003-09-30 devnull 
 60 76193d7c 2003-09-30 devnull 	/* wait for exec'ed program, then exit */
 61 76193d7c 2003-09-30 devnull 	_schedexecwait();
 62 76193d7c 2003-09-30 devnull }
 63 76193d7c 2003-09-30 devnull 
 64 76193d7c 2003-09-30 devnull void
 65 76193d7c 2003-09-30 devnull procexecl(Channel *pidc, char *f, ...)
 66 76193d7c 2003-09-30 devnull {
 67 76193d7c 2003-09-30 devnull 	procexec(pidc, f, &f+1);
 68 76193d7c 2003-09-30 devnull }
 69 76193d7c 2003-09-30 devnull 
 70 76193d7c 2003-09-30 devnull void
 71 76193d7c 2003-09-30 devnull _schedexecwait(void)
 72 76193d7c 2003-09-30 devnull {
 73 76193d7c 2003-09-30 devnull 	int pid;
 74 76193d7c 2003-09-30 devnull 	Channel *c;
 75 76193d7c 2003-09-30 devnull 	Proc *p;
 76 76193d7c 2003-09-30 devnull 	Thread *t;
 77 76193d7c 2003-09-30 devnull 	Waitmsg *w;
 78 76193d7c 2003-09-30 devnull 
 79 76193d7c 2003-09-30 devnull 	p = _threadgetproc();
 80 76193d7c 2003-09-30 devnull 	t = p->thread;
 81 76193d7c 2003-09-30 devnull 	pid = t->ret;
 82 76193d7c 2003-09-30 devnull 	_threaddebug(DBGEXEC, "_schedexecwait %d", t->ret);
 83 76193d7c 2003-09-30 devnull 
 84 76193d7c 2003-09-30 devnull 	for(;;){
 85 76193d7c 2003-09-30 devnull 		w = wait();
 86 76193d7c 2003-09-30 devnull 		if(w == nil)
 87 76193d7c 2003-09-30 devnull 			break;
 88 76193d7c 2003-09-30 devnull 		if(w->pid == pid)
 89 76193d7c 2003-09-30 devnull 			break;
 90 76193d7c 2003-09-30 devnull 		free(w);
 91 76193d7c 2003-09-30 devnull 	}
 92 76193d7c 2003-09-30 devnull 	if(w != nil){
 93 76193d7c 2003-09-30 devnull 		if((c = _threadwaitchan) != nil)
 94 76193d7c 2003-09-30 devnull 			sendp(c, w);
 95 76193d7c 2003-09-30 devnull 		else
 96 76193d7c 2003-09-30 devnull 			free(w);
 97 76193d7c 2003-09-30 devnull 	}
 98 76193d7c 2003-09-30 devnull 	threadexits("procexec");
 99 76193d7c 2003-09-30 devnull }
100 76193d7c 2003-09-30 devnull 
101 76193d7c 2003-09-30 devnull static void
102 76193d7c 2003-09-30 devnull efork(void *ve)
103 76193d7c 2003-09-30 devnull {
104 76193d7c 2003-09-30 devnull 	char buf[ERRMAX];
105 76193d7c 2003-09-30 devnull 	Execargs *e;
106 76193d7c 2003-09-30 devnull 
107 76193d7c 2003-09-30 devnull 	e = ve;
108 76193d7c 2003-09-30 devnull 	_threaddebug(DBGEXEC, "_schedexec %s", e->prog);
109 76193d7c 2003-09-30 devnull 	close(e->fd[0]);
110 76193d7c 2003-09-30 devnull 	execv(e->prog, e->args);
111 76193d7c 2003-09-30 devnull 	_threaddebug(DBGEXEC, "_schedexec failed: %r");
112 76193d7c 2003-09-30 devnull 	rerrstr(buf, sizeof buf);
113 76193d7c 2003-09-30 devnull 	if(buf[0]=='\0')
114 76193d7c 2003-09-30 devnull 		strcpy(buf, "exec failed");
115 76193d7c 2003-09-30 devnull 	write(e->fd[1], buf, strlen(buf));
116 76193d7c 2003-09-30 devnull 	close(e->fd[1]);
117 76193d7c 2003-09-30 devnull 	_exits(buf);
118 76193d7c 2003-09-30 devnull }
119 76193d7c 2003-09-30 devnull 
120 76193d7c 2003-09-30 devnull int
121 76193d7c 2003-09-30 devnull _schedexec(Execargs *e)
122 76193d7c 2003-09-30 devnull {
123 76193d7c 2003-09-30 devnull 	return ffork(RFFDG|RFPROC|RFMEM, efork, e);
124 76193d7c 2003-09-30 devnull }