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 912fba95 2003-11-24 devnull 		_threaddebug(DBGEXEC, "procexec bad %r");
 20 76193d7c 2003-09-30 devnull 		if(pidc)
 21 76193d7c 2003-09-30 devnull 			sendul(pidc, ~0);
 22 76193d7c 2003-09-30 devnull 		return;
 23 76193d7c 2003-09-30 devnull 	}
 24 76193d7c 2003-09-30 devnull 
 25 76193d7c 2003-09-30 devnull 	/*
 26 76193d7c 2003-09-30 devnull 	 * We want procexec to behave like exec; if exec succeeds,
 27 76193d7c 2003-09-30 devnull 	 * never return, and if it fails, return with errstr set.
 28 76193d7c 2003-09-30 devnull 	 * Unfortunately, the exec happens in another proc since
 29 76193d7c 2003-09-30 devnull 	 * we have to wait for the exec'ed process to finish.
 30 76193d7c 2003-09-30 devnull 	 * To provide the semantics, we open a pipe with the 
 31 76193d7c 2003-09-30 devnull 	 * write end close-on-exec and hand it to the proc that
 32 76193d7c 2003-09-30 devnull 	 * is doing the exec.  If the exec succeeds, the pipe will
 33 76193d7c 2003-09-30 devnull 	 * close so that our read below fails.  If the exec fails,
 34 76193d7c 2003-09-30 devnull 	 * then the proc doing the exec sends the errstr down the
 35 76193d7c 2003-09-30 devnull 	 * pipe to us.
 36 76193d7c 2003-09-30 devnull 	 */
 37 76193d7c 2003-09-30 devnull 	if(pipe(p->exec.fd) < 0)
 38 76193d7c 2003-09-30 devnull 		goto Bad;
 39 912fba95 2003-11-24 devnull 	if(fcntl(p->exec.fd[0], F_SETFD, 1) < 0)
 40 912fba95 2003-11-24 devnull 		goto Bad;
 41 76193d7c 2003-09-30 devnull 	if(fcntl(p->exec.fd[1], F_SETFD, 1) < 0)
 42 76193d7c 2003-09-30 devnull 		goto Bad;
 43 76193d7c 2003-09-30 devnull 
 44 76193d7c 2003-09-30 devnull 	/* exec in parallel via the scheduler */
 45 76193d7c 2003-09-30 devnull 	assert(p->needexec==0);
 46 76193d7c 2003-09-30 devnull 	p->exec.prog = prog;
 47 76193d7c 2003-09-30 devnull 	p->exec.args = args;
 48 76193d7c 2003-09-30 devnull 	p->needexec = 1;
 49 76193d7c 2003-09-30 devnull 	_sched();
 50 76193d7c 2003-09-30 devnull 
 51 76193d7c 2003-09-30 devnull 	close(p->exec.fd[1]);
 52 76193d7c 2003-09-30 devnull 	if((n = read(p->exec.fd[0], p->exitstr, ERRMAX-1)) > 0){	/* exec failed */
 53 76193d7c 2003-09-30 devnull 		p->exitstr[n] = '\0';
 54 76193d7c 2003-09-30 devnull 		errstr(p->exitstr, ERRMAX);
 55 76193d7c 2003-09-30 devnull 		close(p->exec.fd[0]);
 56 76193d7c 2003-09-30 devnull 		goto Bad;
 57 76193d7c 2003-09-30 devnull 	}
 58 76193d7c 2003-09-30 devnull 	close(p->exec.fd[0]);
 59 76193d7c 2003-09-30 devnull 
 60 76193d7c 2003-09-30 devnull 	if(pidc)
 61 76193d7c 2003-09-30 devnull 		sendul(pidc, t->ret);
 62 76193d7c 2003-09-30 devnull 
 63 912fba95 2003-11-24 devnull 	_threaddebug(DBGEXEC, "procexec schedexecwait");
 64 76193d7c 2003-09-30 devnull 	/* wait for exec'ed program, then exit */
 65 76193d7c 2003-09-30 devnull 	_schedexecwait();
 66 76193d7c 2003-09-30 devnull }
 67 76193d7c 2003-09-30 devnull 
 68 76193d7c 2003-09-30 devnull void
 69 76193d7c 2003-09-30 devnull procexecl(Channel *pidc, char *f, ...)
 70 76193d7c 2003-09-30 devnull {
 71 76193d7c 2003-09-30 devnull 	procexec(pidc, f, &f+1);
 72 76193d7c 2003-09-30 devnull }
 73 76193d7c 2003-09-30 devnull 
 74 76193d7c 2003-09-30 devnull void
 75 76193d7c 2003-09-30 devnull _schedexecwait(void)
 76 76193d7c 2003-09-30 devnull {
 77 76193d7c 2003-09-30 devnull 	int pid;
 78 76193d7c 2003-09-30 devnull 	Channel *c;
 79 76193d7c 2003-09-30 devnull 	Proc *p;
 80 76193d7c 2003-09-30 devnull 	Thread *t;
 81 76193d7c 2003-09-30 devnull 	Waitmsg *w;
 82 76193d7c 2003-09-30 devnull 
 83 76193d7c 2003-09-30 devnull 	p = _threadgetproc();
 84 76193d7c 2003-09-30 devnull 	t = p->thread;
 85 76193d7c 2003-09-30 devnull 	pid = t->ret;
 86 76193d7c 2003-09-30 devnull 	_threaddebug(DBGEXEC, "_schedexecwait %d", t->ret);
 87 76193d7c 2003-09-30 devnull 
 88 76193d7c 2003-09-30 devnull 	for(;;){
 89 76193d7c 2003-09-30 devnull 		w = wait();
 90 76193d7c 2003-09-30 devnull 		if(w == nil)
 91 76193d7c 2003-09-30 devnull 			break;
 92 76193d7c 2003-09-30 devnull 		if(w->pid == pid)
 93 76193d7c 2003-09-30 devnull 			break;
 94 76193d7c 2003-09-30 devnull 		free(w);
 95 76193d7c 2003-09-30 devnull 	}
 96 76193d7c 2003-09-30 devnull 	if(w != nil){
 97 76193d7c 2003-09-30 devnull 		if((c = _threadwaitchan) != nil)
 98 76193d7c 2003-09-30 devnull 			sendp(c, w);
 99 76193d7c 2003-09-30 devnull 		else
100 76193d7c 2003-09-30 devnull 			free(w);
101 76193d7c 2003-09-30 devnull 	}
102 76193d7c 2003-09-30 devnull 	threadexits("procexec");
103 76193d7c 2003-09-30 devnull }
104 76193d7c 2003-09-30 devnull 
105 76193d7c 2003-09-30 devnull static void
106 76193d7c 2003-09-30 devnull efork(void *ve)
107 76193d7c 2003-09-30 devnull {
108 76193d7c 2003-09-30 devnull 	char buf[ERRMAX];
109 76193d7c 2003-09-30 devnull 	Execargs *e;
110 76193d7c 2003-09-30 devnull 
111 76193d7c 2003-09-30 devnull 	e = ve;
112 912fba95 2003-11-24 devnull 	_threaddebug(DBGEXEC, "_schedexec %s -- calling execv", e->prog);
113 76193d7c 2003-09-30 devnull 	execv(e->prog, e->args);
114 76193d7c 2003-09-30 devnull 	_threaddebug(DBGEXEC, "_schedexec failed: %r");
115 76193d7c 2003-09-30 devnull 	rerrstr(buf, sizeof buf);
116 76193d7c 2003-09-30 devnull 	if(buf[0]=='\0')
117 76193d7c 2003-09-30 devnull 		strcpy(buf, "exec failed");
118 76193d7c 2003-09-30 devnull 	write(e->fd[1], buf, strlen(buf));
119 76193d7c 2003-09-30 devnull 	close(e->fd[1]);
120 76193d7c 2003-09-30 devnull 	_exits(buf);
121 76193d7c 2003-09-30 devnull }
122 76193d7c 2003-09-30 devnull 
123 76193d7c 2003-09-30 devnull int
124 76193d7c 2003-09-30 devnull _schedexec(Execargs *e)
125 76193d7c 2003-09-30 devnull {
126 912fba95 2003-11-24 devnull 	int pid;
127 912fba95 2003-11-24 devnull 
128 912fba95 2003-11-24 devnull 	pid = fork();
129 912fba95 2003-11-24 devnull 	if(pid == 0){
130 912fba95 2003-11-24 devnull 		efork(e);
131 912fba95 2003-11-24 devnull 		_exit(1);
132 912fba95 2003-11-24 devnull 	}
133 912fba95 2003-11-24 devnull 	return pid;
134 76193d7c 2003-09-30 devnull }