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 32f69c36 2003-12-11 devnull procexec(Channel *pidc, int fd[3], 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 32f69c36 2003-12-11 devnull 	p->exec.stdfd = fd;
 49 76193d7c 2003-09-30 devnull 	p->needexec = 1;
 50 76193d7c 2003-09-30 devnull 	_sched();
 51 76193d7c 2003-09-30 devnull 
 52 76193d7c 2003-09-30 devnull 	close(p->exec.fd[1]);
 53 76193d7c 2003-09-30 devnull 	if((n = read(p->exec.fd[0], p->exitstr, ERRMAX-1)) > 0){	/* exec failed */
 54 76193d7c 2003-09-30 devnull 		p->exitstr[n] = '\0';
 55 76193d7c 2003-09-30 devnull 		errstr(p->exitstr, ERRMAX);
 56 76193d7c 2003-09-30 devnull 		close(p->exec.fd[0]);
 57 76193d7c 2003-09-30 devnull 		goto Bad;
 58 76193d7c 2003-09-30 devnull 	}
 59 76193d7c 2003-09-30 devnull 	close(p->exec.fd[0]);
 60 32f69c36 2003-12-11 devnull 	close(fd[0]);
 61 32f69c36 2003-12-11 devnull 	if(fd[1] != fd[0])
 62 32f69c36 2003-12-11 devnull 		close(fd[1]);
 63 32f69c36 2003-12-11 devnull 	if(fd[2] != fd[1] && fd[2] != fd[0])
 64 32f69c36 2003-12-11 devnull 		close(fd[2]);
 65 76193d7c 2003-09-30 devnull 	if(pidc)
 66 76193d7c 2003-09-30 devnull 		sendul(pidc, t->ret);
 67 76193d7c 2003-09-30 devnull 
 68 912fba95 2003-11-24 devnull 	_threaddebug(DBGEXEC, "procexec schedexecwait");
 69 76193d7c 2003-09-30 devnull 	/* wait for exec'ed program, then exit */
 70 76193d7c 2003-09-30 devnull 	_schedexecwait();
 71 76193d7c 2003-09-30 devnull }
 72 76193d7c 2003-09-30 devnull 
 73 76193d7c 2003-09-30 devnull void
 74 32f69c36 2003-12-11 devnull procexecl(Channel *pidc, int fd[3], char *f, ...)
 75 76193d7c 2003-09-30 devnull {
 76 32f69c36 2003-12-11 devnull 	procexec(pidc, fd, f, &f+1);
 77 76193d7c 2003-09-30 devnull }
 78 76193d7c 2003-09-30 devnull 
 79 76193d7c 2003-09-30 devnull void
 80 76193d7c 2003-09-30 devnull _schedexecwait(void)
 81 76193d7c 2003-09-30 devnull {
 82 76193d7c 2003-09-30 devnull 	int pid;
 83 76193d7c 2003-09-30 devnull 	Channel *c;
 84 76193d7c 2003-09-30 devnull 	Proc *p;
 85 76193d7c 2003-09-30 devnull 	Thread *t;
 86 76193d7c 2003-09-30 devnull 	Waitmsg *w;
 87 76193d7c 2003-09-30 devnull 
 88 76193d7c 2003-09-30 devnull 	p = _threadgetproc();
 89 76193d7c 2003-09-30 devnull 	t = p->thread;
 90 76193d7c 2003-09-30 devnull 	pid = t->ret;
 91 76193d7c 2003-09-30 devnull 	_threaddebug(DBGEXEC, "_schedexecwait %d", t->ret);
 92 76193d7c 2003-09-30 devnull 
 93 76193d7c 2003-09-30 devnull 	for(;;){
 94 76193d7c 2003-09-30 devnull 		w = wait();
 95 76193d7c 2003-09-30 devnull 		if(w == nil)
 96 76193d7c 2003-09-30 devnull 			break;
 97 76193d7c 2003-09-30 devnull 		if(w->pid == pid)
 98 76193d7c 2003-09-30 devnull 			break;
 99 76193d7c 2003-09-30 devnull 		free(w);
100 76193d7c 2003-09-30 devnull 	}
101 76193d7c 2003-09-30 devnull 	if(w != nil){
102 76193d7c 2003-09-30 devnull 		if((c = _threadwaitchan) != nil)
103 76193d7c 2003-09-30 devnull 			sendp(c, w);
104 76193d7c 2003-09-30 devnull 		else
105 76193d7c 2003-09-30 devnull 			free(w);
106 76193d7c 2003-09-30 devnull 	}
107 76193d7c 2003-09-30 devnull 	threadexits("procexec");
108 76193d7c 2003-09-30 devnull }
109 76193d7c 2003-09-30 devnull 
110 76193d7c 2003-09-30 devnull static void
111 76193d7c 2003-09-30 devnull efork(void *ve)
112 76193d7c 2003-09-30 devnull {
113 76193d7c 2003-09-30 devnull 	char buf[ERRMAX];
114 76193d7c 2003-09-30 devnull 	Execargs *e;
115 32f69c36 2003-12-11 devnull 	int i;
116 76193d7c 2003-09-30 devnull 
117 76193d7c 2003-09-30 devnull 	e = ve;
118 912fba95 2003-11-24 devnull 	_threaddebug(DBGEXEC, "_schedexec %s -- calling execv", e->prog);
119 32f69c36 2003-12-11 devnull 	dup(e->stdfd[0], 0);
120 32f69c36 2003-12-11 devnull 	dup(e->stdfd[1], 1);
121 32f69c36 2003-12-11 devnull 	dup(e->stdfd[2], 2);
122 32f69c36 2003-12-11 devnull 	for(i=3; i<40; i++)
123 32f69c36 2003-12-11 devnull 		if(i != e->fd[1])
124 32f69c36 2003-12-11 devnull 			close(i);
125 32f69c36 2003-12-11 devnull 	execvp(e->prog, e->args);
126 76193d7c 2003-09-30 devnull 	_threaddebug(DBGEXEC, "_schedexec failed: %r");
127 76193d7c 2003-09-30 devnull 	rerrstr(buf, sizeof buf);
128 76193d7c 2003-09-30 devnull 	if(buf[0]=='\0')
129 76193d7c 2003-09-30 devnull 		strcpy(buf, "exec failed");
130 76193d7c 2003-09-30 devnull 	write(e->fd[1], buf, strlen(buf));
131 76193d7c 2003-09-30 devnull 	close(e->fd[1]);
132 76193d7c 2003-09-30 devnull 	_exits(buf);
133 76193d7c 2003-09-30 devnull }
134 76193d7c 2003-09-30 devnull 
135 76193d7c 2003-09-30 devnull int
136 76193d7c 2003-09-30 devnull _schedexec(Execargs *e)
137 76193d7c 2003-09-30 devnull {
138 912fba95 2003-11-24 devnull 	int pid;
139 912fba95 2003-11-24 devnull 
140 912fba95 2003-11-24 devnull 	pid = fork();
141 912fba95 2003-11-24 devnull 	if(pid == 0){
142 912fba95 2003-11-24 devnull 		efork(e);
143 912fba95 2003-11-24 devnull 		_exit(1);
144 912fba95 2003-11-24 devnull 	}
145 912fba95 2003-11-24 devnull 	return pid;
146 76193d7c 2003-09-30 devnull }