X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/943685687a914f34bb028d07fefeff4a802b6d5b..fa8705966e8de1c5c08ef6111d371e95203a1661:/usr/src/sys/kern/kern_exit.c

diff --git a/usr/src/sys/kern/kern_exit.c b/usr/src/sys/kern/kern_exit.c
index 375ce2db25..db2e2d3fec 100644
--- a/usr/src/sys/kern/kern_exit.c
+++ b/usr/src/sys/kern/kern_exit.c
@@ -1,258 +1,444 @@
-/*	kern_exit.c	6.4	84/08/29	*/
-
-#include "../machine/reg.h"
-#include "../machine/psl.h"
+/*
+ * Copyright (c) 1982, 1986, 1989, 1991 Regents of the University of California.
+ * All rights reserved.
+ *
+ * %sccs.include.redist.c%
+ *
+ *	@(#)kern_exit.c	7.49 (Berkeley) %G%
+ */
 
 #include "param.h"
 #include "systm.h"
 #include "map.h"
-#include "dir.h"
-#include "user.h"
-#include "kernel.h"
+#include "ioctl.h"
 #include "proc.h"
+#include "tty.h"
+#include "time.h"
+#include "resource.h"
+#include "kernel.h"
 #include "buf.h"
 #include "wait.h"
-#include "vm.h"
 #include "file.h"
-#include "mbuf.h"
-#include "inode.h"
+#include "vnode.h"
+#include "syslog.h"
+#include "malloc.h"
+#include "resourcevar.h"
+#include "ptrace.h"
+
+#include "machine/cpu.h"
+#ifdef COMPAT_43
+#include "machine/reg.h"
+#include "machine/psl.h"
+#endif
+
+#include "vm/vm.h"
+#include "vm/vm_kern.h"
 
 /*
  * Exit system call: pass back caller's arg
  */
-rexit()
+struct rexit_args {
+	int	rval;
+};
+/* ARGSUSED */
+rexit(p, uap, retval)
+	struct proc *p;
+	struct rexit_args *uap;
+	int *retval;
 {
-	register struct a {
-		int	rval;
-	} *uap;
 
-	uap = (struct a *)u.u_ap;
-	exit((uap->rval & 0377) << 8);
+	exit(p, W_EXITCODE(uap->rval, 0));
+	/* NOTREACHED */
 }
 
 /*
- * Release resources.
- * Save u. area for parent to look at.
- * Enter zombie state.
- * Wake up parent and init processes,
- * and dispose of children.
+ * Exit: deallocate address space and other resources,
+ * change proc state to zombie, and unlink proc from allproc
+ * and parent's lists.  Save exit status and rusage for wait().
+ * Check for child processes and orphan them.
  */
-exit(rv)
+exit(p, rv)
+	register struct proc *p;
 	int rv;
 {
-	register int i;
-	register struct proc *p, *q, *nq;
-	register int x;
-	struct mbuf *m = m_getclr(M_WAIT, MT_ZOMBIE);
+	register struct proc *q, *nq;
+	register struct proc **pp;
+	register struct vmspace *vm;
+	int s;
 
+	if (p->p_pid == 1)
+		panic("init died (signal %d, exit %d)",
+		    WTERMSIG(rv), WEXITSTATUS(rv));
 #ifdef PGINPROF
 	vmsizmon();
 #endif
-	p = u.u_procp;
-	p->p_flag &= ~(STRC|SULOCK);
+	if (p->p_flag & SPROFIL)
+		stopprofclock(p);
+	MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
+		M_ZOMBIE, M_WAITOK);
+	/*
+	 * If parent is waiting for us to exit or exec,
+	 * SPPWAIT is set; we will wakeup the parent below.
+	 */
+	p->p_flag &= ~(STRC|SPPWAIT);
 	p->p_flag |= SWEXIT;
 	p->p_sigignore = ~0;
-	p->p_cpticks = 0;
-	p->p_pctcpu = 0;
-	for (i = 0; i < NSIG; i++)
-		u.u_signal[i] = SIG_IGN;
+	p->p_sig = 0;
 	untimeout(realitexpire, (caddr_t)p);
+
 	/*
-	 * Release virtual memory.  If we resulted from
-	 * a vfork(), instead give the resources back to
-	 * the parent.
+	 * Close open files and release open-file table.
+	 * This may block!
 	 */
-	if ((p->p_flag & SVFORK) == 0)
-		vrelvm();
-	else {
-		p->p_flag &= ~SVFORK;
-		wakeup((caddr_t)p);
-		while ((p->p_flag & SVFDONE) == 0)
-			sleep((caddr_t)p, PZERO - 1);
-		p->p_flag &= ~SVFDONE;
-	}
-	for (i = 0; i < NOFILE; i++) {
-		struct file *f;
+	fdfree(p);
 
-		f = u.u_ofile[i];
-		u.u_ofile[i] = NULL;
-		u.u_pofile[i] = 0;
-		closef(f);
-	}
-	ilock(u.u_cdir);
-	iput(u.u_cdir);
-	if (u.u_rdir) {
-		ilock(u.u_rdir);
-		iput(u.u_rdir);
+	/* The next two chunks should probably be moved to vmspace_exit. */
+	vm = p->p_vmspace;
+#ifdef SYSVSHM
+	if (vm->vm_shm)
+		shmexit(p);
+#endif
+	/*
+	 * Release user portion of address space.
+	 * This releases references to vnodes,
+	 * which could cause I/O if the file has been unlinked.
+	 * Need to do this early enough that we can still sleep.
+	 * Can't free the entire vmspace as the kernel stack
+	 * may be mapped within that space also.
+	 */
+	if (vm->vm_refcnt == 1)
+		(void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS,
+		    VM_MAXUSER_ADDRESS);
+
+	if (SESS_LEADER(p)) {
+		register struct session *sp = p->p_session;
+
+		if (sp->s_ttyvp) {
+			/*
+			 * Controlling process.
+			 * Signal foreground pgrp,
+			 * drain controlling terminal
+			 * and revoke access to controlling terminal.
+			 */
+			if (sp->s_ttyp->t_session == sp) {
+				if (sp->s_ttyp->t_pgrp)
+					pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
+				(void) ttywait(sp->s_ttyp);
+				vgoneall(sp->s_ttyvp);
+			}
+			vrele(sp->s_ttyvp);
+			sp->s_ttyvp = NULL;
+			/*
+			 * s_ttyp is not zero'd; we use this to indicate
+			 * that the session once had a controlling terminal.
+			 * (for logging and informational purposes)
+			 */
+		}
+		sp->s_leader = NULL;
 	}
-	u.u_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
-	acct();
-#ifdef QUOTA
-	qclean();
+	fixjobc(p, p->p_pgrp, 0);
+	p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
+	(void) acct(p);
+#ifdef KTRACE
+	/* 
+	 * release trace file
+	 */
+	p->p_traceflag = 0;	/* don't trace the vrele() */
+	if (p->p_tracep)
+		vrele(p->p_tracep);
 #endif
-	vrelpt(u.u_procp);
-	vrelu(u.u_procp, 0);
-	(void) spl5();		/* hack for mem alloc race XXX */
-	if (*p->p_prev = p->p_nxt)		/* off allproc queue */
+	/*
+	 * Remove proc from allproc queue and pidhash chain.
+	 * Place onto zombproc.  Unlink from parent's child list.
+	 */
+	if (*p->p_prev = p->p_nxt)
 		p->p_nxt->p_prev = p->p_prev;
-	if (p->p_nxt = zombproc)		/* onto zombproc */
+	if (p->p_nxt = zombproc)
 		p->p_nxt->p_prev = &p->p_nxt;
 	p->p_prev = &zombproc;
 	zombproc = p;
-	multprog--;
 	p->p_stat = SZOMB;
-	noproc = 1;
-	i = PIDHASH(p->p_pid);
-	x = p - proc;
-	if (pidhash[i] == x)
-		pidhash[i] = p->p_idhash;
-	else {
-		for (i = pidhash[i]; i != 0; i = proc[i].p_idhash)
-			if (proc[i].p_idhash == x) {
-				proc[i].p_idhash = p->p_idhash;
-				goto done;
-			}
-		panic("exit");
-	}
-	if (p->p_pid == 1)
-		panic("init died");
+
+	for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash)
+		if (*pp == p) {
+			*pp = p->p_hash;
+			goto done;
+		}
+	panic("exit");
 done:
-	p->p_xstat = rv;
-if (m == 0)
-panic("exit: m_getclr");
-	p->p_ru = mtod(m, struct rusage *);
-	*p->p_ru = u.u_ru;
-	ruadd(p->p_ru, &u.u_cru);
+
 	if (p->p_cptr)		/* only need this if any child is S_ZOMB */
-		wakeup((caddr_t)&proc[1]);
+		wakeup((caddr_t) initproc);
 	for (q = p->p_cptr; q != NULL; q = nq) {
 		nq = q->p_osptr;
 		if (nq != NULL)
 			nq->p_ysptr = NULL;
-		if (proc[1].p_cptr)
-			proc[1].p_cptr->p_ysptr = q;
-		q->p_osptr = proc[1].p_cptr;
+		if (initproc->p_cptr)
+			initproc->p_cptr->p_ysptr = q;
+		q->p_osptr = initproc->p_cptr;
 		q->p_ysptr = NULL;
-		proc[1].p_cptr = q;
+		initproc->p_cptr = q;
 
-		q->p_pptr = &proc[1];
-		q->p_ppid = 1;
+		q->p_pptr = initproc;
 		/*
 		 * Traced processes are killed
 		 * since their existence means someone is screwing up.
-		 * Stopped processes are sent a hangup and a continue.
-		 * This is designed to be ``safe'' for setuid
-		 * processes since they must be willing to tolerate
-		 * hangups anyways.
 		 */
 		if (q->p_flag&STRC) {
 			q->p_flag &= ~STRC;
 			psignal(q, SIGKILL);
-		} else if (q->p_stat == SSTOP) {
-			psignal(q, SIGHUP);
-			psignal(q, SIGCONT);
 		}
-		/*
-		 * Protect this process from future
-		 * tty signals, clear TSTP/TTIN/TTOU if pending.
-		 */
-		(void) spgrp(q, -1);
 	}
+	p->p_cptr = NULL;
+
+	/*
+	 * Save exit status and final rusage info, adding in child rusage
+	 * info and self times.
+	 */
+	p->p_xstat = rv;
+	*p->p_ru = p->p_stats->p_ru;
+	calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
+	ruadd(p->p_ru, &p->p_stats->p_cru);
+
+	/*
+	 * Notify parent that we're gone.
+	 */
 	psignal(p->p_pptr, SIGCHLD);
 	wakeup((caddr_t)p->p_pptr);
-	swtch();
+#if defined(tahoe)
+	/* move this to cpu_exit */
+	p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL;
+#endif
+	/*
+	 * Clear curproc after we've done all operations
+	 * that could block, and before tearing down the rest
+	 * of the process state that might be used from clock, etc.
+	 * Also, can't clear curproc while we're still runnable,
+	 * as we're not on a run queue (we are current, just not
+	 * a proper proc any longer!).
+	 *
+	 * Other substructures are freed from wait().
+	 */
+	curproc = NULL;
+	if (--p->p_limit->p_refcnt == 0)
+		FREE(p->p_limit, M_SUBPROC);
+
+	/*
+	 * Finally, call machine-dependent code to release the remaining
+	 * resources including address space, the kernel stack and pcb.
+	 * The address space is released by "vmspace_free(p->p_vmspace)";
+	 * This is machine-dependent, as we may have to change stacks
+	 * or ensure that the current one isn't reallocated before we
+	 * finish.  cpu_exit will end with a call to cpu_swtch(), finishing
+	 * our execution (pun intended).
+	 */
+	cpu_exit(p);
+	/* NOTREACHED */
 }
 
-wait()
+struct wait_args {
+	int	pid;
+	int	*status;
+	int	options;
+	struct	rusage *rusage;
+#ifdef COMPAT_43
+	int	compat;		/* pseudo */
+#endif
+};
+
+#ifdef COMPAT_43
+owait(p, uap, retval)
+	struct proc *p;
+	register struct wait_args *uap;
+	int *retval;
 {
-	struct rusage ru, *rup;
 
-	if ((u.u_ar0[PS] & PSL_ALLCC) != PSL_ALLCC) {
-		u.u_error = wait1(0, (struct rusage *)0);
-		return;
+#ifdef PSL_ALLCC
+	if ((p->p_md.md_regs[PS] & PSL_ALLCC) != PSL_ALLCC) {
+		uap->options = 0;
+		uap->rusage = NULL;
+	} else {
+		uap->options = p->p_md.md_regs[R0];
+		uap->rusage = (struct rusage *)p->p_md.md_regs[R1];
 	}
-	rup = (struct rusage *)u.u_ar0[R1];
-	u.u_error = wait1(u.u_ar0[R0], &ru);
-	if (u.u_error)
-		return;
-	if (rup != (struct rusage *)0)
-		u.u_error = copyout((caddr_t)&ru, (caddr_t)rup,
-		    sizeof (struct rusage));
+#else
+	uap->options = 0;
+	uap->rusage = NULL;
+#endif
+	uap->pid = WAIT_ANY;
+	uap->status = NULL;
+	uap->compat = 1;
+	return (wait1(p, uap, retval));
+}
+
+wait4(p, uap, retval)
+	struct proc *p;
+	struct wait_args *uap;
+	int *retval;
+{
+
+	uap->compat = 0;
+	return (wait1(p, uap, retval));
 }
+#else
+#define	wait1	wait4
+#endif
 
 /*
- * Wait system call.
- * Search for a terminated (zombie) child,
- * finally lay it to rest, and collect its status.
- * Look also for stopped (traced) children,
- * and pass back status from them.
+ * Wait: check child processes to see if any have exited,
+ * stopped under trace, or (optionally) stopped by a signal.
+ * Pass back status and deallocate exited child's proc structure.
  */
-wait1(options, ru)
-	register int options;
-	struct rusage *ru;
+wait1(q, uap, retval)
+	register struct proc *q;
+	register struct wait_args *uap;
+	int retval[];
 {
-	register f;
-	register struct proc *p, *q;
+	register int nfound;
+	register struct proc *p, *t;
+	int status, error;
 
-	f = 0;
+	if (uap->pid == 0)
+		uap->pid = -q->p_pgid;
+#ifdef notyet
+	if (uap->options &~ (WUNTRACED|WNOHANG))
+		return (EINVAL);
+#endif
 loop:
-	q = u.u_procp;
+	nfound = 0;
 	for (p = q->p_cptr; p; p = p->p_osptr) {
-		f++;
+		if (uap->pid != WAIT_ANY &&
+		    p->p_pid != uap->pid && p->p_pgid != -uap->pid)
+			continue;
+		nfound++;
 		if (p->p_stat == SZOMB) {
-			u.u_r.r_val1 = p->p_pid;
-			u.u_r.r_val2 = p->p_xstat;
+			retval[0] = p->p_pid;
+#ifdef COMPAT_43
+			if (uap->compat)
+				retval[1] = p->p_xstat;
+			else
+#endif
+			if (uap->status) {
+				status = p->p_xstat;	/* convert to int */
+				if (error = copyout((caddr_t)&status,
+				    (caddr_t)uap->status, sizeof(status)))
+					return (error);
+			}
+			if (uap->rusage && (error = copyout((caddr_t)p->p_ru,
+			    (caddr_t)uap->rusage, sizeof (struct rusage))))
+				return (error);
+			/*
+			 * If we got the child via a ptrace 'attach',
+			 * we need to give it back to the old parent.
+			 */
+			if (p->p_oppid && (t = pfind(p->p_oppid))) {
+				p->p_oppid = 0;
+				proc_reparent(p, t);
+				psignal(t, SIGCHLD);
+				wakeup((caddr_t)t);
+				return (0);
+			}
 			p->p_xstat = 0;
-			if (ru)
-				*ru = *p->p_ru;
-			ruadd(&u.u_cru, p->p_ru);
-			(void) m_free(dtom(p->p_ru));
-			p->p_ru = 0;
-			p->p_stat = NULL;
-			p->p_pid = 0;
-			p->p_ppid = 0;
+			ruadd(&q->p_stats->p_cru, p->p_ru);
+			FREE(p->p_ru, M_ZOMBIE);
+
+			/*
+			 * Decrement the count of procs running with this uid.
+			 */
+			(void)chgproccnt(p->p_cred->p_ruid, -1);
+
+			/*
+			 * Free up credentials.
+			 */
+			if (--p->p_cred->p_refcnt == 0) {
+				crfree(p->p_cred->pc_ucred);
+				FREE(p->p_cred, M_SUBPROC);
+			}
+
+			/*
+			 * Finally finished with old proc entry.
+			 * Unlink it from its process group and free it.
+			 */
+			leavepgrp(p);
 			if (*p->p_prev = p->p_nxt)	/* off zombproc */
 				p->p_nxt->p_prev = p->p_prev;
-			p->p_nxt = freeproc;		/* onto freeproc */
-			freeproc = p;
 			if (q = p->p_ysptr)
 				q->p_osptr = p->p_osptr;
 			if (q = p->p_osptr)
 				q->p_ysptr = p->p_ysptr;
 			if ((q = p->p_pptr)->p_cptr == p)
 				q->p_cptr = p->p_osptr;
-			p->p_pptr = 0;
-			p->p_ysptr = 0;
-			p->p_osptr = 0;
-			p->p_cptr = 0;
-			p->p_sig = 0;
-			p->p_sigcatch = 0;
-			p->p_sigignore = 0;
-			p->p_sigmask = 0;
-			p->p_pgrp = 0;
-			p->p_flag = 0;
-			p->p_wchan = 0;
-			p->p_cursig = 0;
+
+			/*
+			 * Give machine-dependent layer a chance
+			 * to free anything that cpu_exit couldn't
+			 * release while still running in process context.
+			 */
+			cpu_wait(p);
+			FREE(p, M_PROC);
+			nprocs--;
 			return (0);
 		}
-		if (p->p_stat == SSTOP && (p->p_flag&SWTED)==0 &&
-		    (p->p_flag&STRC || options&WUNTRACED)) {
+		if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 &&
+		    (p->p_flag & STRC || uap->options & WUNTRACED)) {
 			p->p_flag |= SWTED;
-			u.u_r.r_val1 = p->p_pid;
-			u.u_r.r_val2 = (p->p_cursig<<8) | WSTOPPED;
-			return (0);
+			retval[0] = p->p_pid;
+#ifdef COMPAT_43
+			if (uap->compat) {
+				retval[1] = W_STOPCODE(p->p_xstat);
+				error = 0;
+			} else
+#endif
+			if (uap->status) {
+				status = W_STOPCODE(p->p_xstat);
+				error = copyout((caddr_t)&status,
+					(caddr_t)uap->status, sizeof(status));
+			} else
+				error = 0;
+			return (error);
 		}
 	}
-	if (f == 0)
+	if (nfound == 0)
 		return (ECHILD);
-	if (options&WNOHANG) {
-		u.u_r.r_val1 = 0;
-		return (0);
-	}
-	if ((u.u_procp->p_flag&SOUSIG) == 0 && setjmp(&u.u_qsave)) {
-		u.u_eosys = RESTARTSYS;
+	if (uap->options & WNOHANG) {
+		retval[0] = 0;
 		return (0);
 	}
-	sleep((caddr_t)u.u_procp, PWAIT);
+	if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))
+		return (error);
 	goto loop;
 }
+
+/*
+ * make process 'parent' the new parent of process 'child'.
+ */
+void
+proc_reparent(child, parent)
+	register struct proc *child;
+	register struct proc *parent;
+{
+	register struct proc *o;
+	register struct proc *y;
+
+	if (child->p_pptr == parent)
+		return;
+
+	/* fix up the child linkage for the old parent */
+	o = child->p_osptr;
+	y = child->p_ysptr;
+	if (y)
+		y->p_osptr = o;
+	if (o)
+		o->p_ysptr = y;
+	if (child->p_pptr->p_cptr == child)
+		child->p_pptr->p_cptr = o;
+
+	/* fix up child linkage for new parent */
+	o = parent->p_cptr;
+	if (o)
+		o->p_ysptr = child;
+	child->p_osptr = o;
+	child->p_ysptr = NULL;
+	parent->p_cptr = child;
+	child->p_pptr = parent;
+}