xref: /csrg-svn/sys/kern/kern_exit.c (revision 13159)
1 /*	kern_exit.c	4.5	83/06/16	*/
2 
3 #include "../machine/reg.h"
4 #include "../machine/psl.h"
5 
6 #include "../h/param.h"
7 #include "../h/systm.h"
8 #include "../h/map.h"
9 #include "../h/dir.h"
10 #include "../h/user.h"
11 #include "../h/kernel.h"
12 #include "../h/proc.h"
13 #include "../h/buf.h"
14 #include "../h/wait.h"
15 #include "../h/vm.h"
16 #include "../h/file.h"
17 #include "../h/mbuf.h"
18 #include "../h/inode.h"
19 
20 /*
21  * Exit system call: pass back caller's arg
22  */
23 rexit()
24 {
25 	register struct a {
26 		int	rval;
27 	} *uap;
28 
29 	uap = (struct a *)u.u_ap;
30 	exit((uap->rval & 0377) << 8);
31 }
32 
33 /*
34  * Release resources.
35  * Save u. area for parent to look at.
36  * Enter zombie state.
37  * Wake up parent and init processes,
38  * and dispose of children.
39  */
40 exit(rv)
41 	int rv;
42 {
43 	register int i;
44 	register struct proc *p, *q;
45 	register int x;
46 	struct mbuf *m = m_getclr(M_WAIT, MT_ZOMBIE);
47 
48 #ifdef PGINPROF
49 	vmsizmon();
50 #endif
51 	p = u.u_procp;
52 	p->p_flag &= ~(STRC|SULOCK);
53 	p->p_flag |= SWEXIT;
54 	p->p_sigignore = ~0;
55 	p->p_cpticks = 0;
56 	p->p_pctcpu = 0;
57 	for (i = 0; i < NSIG; i++)
58 		u.u_signal[i] = SIG_IGN;
59 	untimeout(realitexpire, (caddr_t)p);
60 	/*
61 	 * Release virtual memory.  If we resulted from
62 	 * a vfork(), instead give the resources back to
63 	 * the parent.
64 	 */
65 	if ((p->p_flag & SVFORK) == 0)
66 		vrelvm();
67 	else {
68 		p->p_flag &= ~SVFORK;
69 		wakeup((caddr_t)p);
70 		while ((p->p_flag & SVFDONE) == 0)
71 			sleep((caddr_t)p, PZERO - 1);
72 		p->p_flag &= ~SVFDONE;
73 	}
74 	for (i = 0; i < NOFILE; i++) {
75 		struct file *f;
76 
77 		f = u.u_ofile[i];
78 		u.u_ofile[i] = NULL;
79 		u.u_pofile[i] = 0;
80 		closef(f);
81 	}
82 	ilock(u.u_cdir);
83 	iput(u.u_cdir);
84 	if (u.u_rdir) {
85 		ilock(u.u_rdir);
86 		iput(u.u_rdir);
87 	}
88 	u.u_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
89 	acct();
90 #ifdef QUOTA
91 	qclean();
92 #endif
93 #ifdef sun
94 	ctxfree(u.u_procp);
95 #endif
96 	vrelpt(u.u_procp);
97 	vrelu(u.u_procp, 0);
98 	(void) spl5();		/* hack for mem alloc race XXX */
99 	multprog--;
100 	p->p_stat = SZOMB;
101 	noproc = 1;
102 	i = PIDHASH(p->p_pid);
103 	x = p - proc;
104 	if (pidhash[i] == x)
105 		pidhash[i] = p->p_idhash;
106 	else {
107 		for (i = pidhash[i]; i != 0; i = proc[i].p_idhash)
108 			if (proc[i].p_idhash == x) {
109 				proc[i].p_idhash = p->p_idhash;
110 				goto done;
111 			}
112 		panic("exit");
113 	}
114 	if (p->p_pid == 1)
115 		panic("init died");
116 done:
117 	p->p_xstat = rv;
118 if (m == 0)
119 panic("exit: m_getclr");
120 	p->p_ru = mtod(m, struct rusage *);
121 	*p->p_ru = u.u_ru;
122 	ruadd(p->p_ru, &u.u_cru);
123 	for (q = proc; q < procNPROC; q++)
124 		if (q->p_pptr == p) {
125 			if (q->p_osptr)
126 				q->p_osptr->p_ysptr = q->p_ysptr;
127 			if (q->p_ysptr)
128 				q->p_ysptr->p_osptr = q->p_osptr;
129 			if (proc[1].p_cptr)
130 				proc[1].p_cptr->p_ysptr = q;
131 			q->p_osptr = proc[1].p_cptr;
132 			q->p_ysptr = NULL;
133 			proc[1].p_cptr = q;
134 
135 			q->p_pptr = &proc[1];
136 			q->p_ppid = 1;
137 			wakeup((caddr_t)&proc[1]);
138 			/*
139 			 * Traced processes are killed
140 			 * since their existence means someone is screwing up.
141 			 * Stopped processes are sent a hangup and a continue.
142 			 * This is designed to be ``safe'' for setuid
143 			 * processes since they must be willing to tolerate
144 			 * hangups anyways.
145 			 */
146 			if (q->p_flag&STRC) {
147 				q->p_flag &= ~STRC;
148 				psignal(q, SIGKILL);
149 			} else if (q->p_stat == SSTOP) {
150 				psignal(q, SIGHUP);
151 				psignal(q, SIGCONT);
152 			}
153 			/*
154 			 * Protect this process from future
155 			 * tty signals, clear TSTP/TTIN/TTOU if pending.
156 			 */
157 			(void) spgrp(q, -1);
158 		}
159 	psignal(p->p_pptr, SIGCHLD);
160 	wakeup((caddr_t)p->p_pptr);
161 	swtch();
162 }
163 
164 wait()
165 {
166 	struct rusage ru, *rup;
167 
168 	if ((u.u_ar0[PS] & PSL_ALLCC) != PSL_ALLCC) {
169 		u.u_error = wait1(0, (struct rusage *)0);
170 		return;
171 	}
172 	rup = (struct rusage *)u.u_ar0[R1];
173 	u.u_error = wait1(u.u_ar0[R0], &ru);
174 	if (u.u_error)
175 		return;
176 	(void) copyout((caddr_t)&ru, (caddr_t)rup, sizeof (struct rusage));
177 }
178 
179 /*
180  * Wait system call.
181  * Search for a terminated (zombie) child,
182  * finally lay it to rest, and collect its status.
183  * Look also for stopped (traced) children,
184  * and pass back status from them.
185  */
186 wait1(options, ru)
187 	register int options;
188 	struct rusage *ru;
189 {
190 	register f;
191 	register struct proc *p, *q;
192 
193 	f = 0;
194 loop:
195 	for (p = proc; p < procNPROC; p++)
196 	if (p->p_pptr == u.u_procp) {
197 		f++;
198 		if (p->p_stat == SZOMB) {
199 			u.u_r.r_val1 = p->p_pid;
200 			u.u_r.r_val2 = p->p_xstat;
201 			p->p_xstat = 0;
202 			if (ru)
203 				*ru = *p->p_ru;
204 			ruadd(&u.u_cru, p->p_ru);
205 			(void) m_free(dtom(p->p_ru));
206 			p->p_ru = 0;
207 			p->p_stat = NULL;
208 			p->p_pid = 0;
209 			p->p_ppid = 0;
210 			if (q = p->p_ysptr)
211 				q->p_osptr = p->p_osptr;
212 			if (q = p->p_osptr)
213 				q->p_ysptr = p->p_ysptr;
214 			if ((q = p->p_pptr)->p_cptr == p)
215 				q->p_cptr = p->p_osptr;
216 			p->p_pptr = 0;
217 			p->p_ysptr = 0;
218 			p->p_osptr = 0;
219 			p->p_cptr = 0;
220 			p->p_sig = 0;
221 			p->p_sigcatch = 0;
222 			p->p_sigignore = 0;
223 			p->p_sigmask = 0;
224 			p->p_pgrp = 0;
225 			p->p_flag = 0;
226 			p->p_wchan = 0;
227 			p->p_cursig = 0;
228 			return (0);
229 		}
230 		if (p->p_stat == SSTOP && (p->p_flag&SWTED)==0 &&
231 		    (p->p_flag&STRC || options&WUNTRACED)) {
232 			p->p_flag |= SWTED;
233 			u.u_r.r_val1 = p->p_pid;
234 			u.u_r.r_val2 = (p->p_cursig<<8) | WSTOPPED;
235 			return (0);
236 		}
237 	}
238 	if (f == 0)
239 		return (ECHILD);
240 	if (options&WNOHANG) {
241 		u.u_r.r_val1 = 0;
242 		return (0);
243 	}
244 	if ((u.u_procp->p_flag&SOUSIG) == 0 && setjmp(&u.u_qsave)) {
245 		u.u_eosys = RESTARTSYS;
246 		return (0);
247 	}
248 	sleep((caddr_t)u.u_procp, PWAIT);
249 	goto loop;
250 }
251