4.4BSD/usr/src/sys/kern/kern_proc.c
/*
* Copyright (c) 1982, 1986, 1989, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_proc.c 8.1 (Berkeley) 6/10/93
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/map.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/acct.h>
#include <sys/wait.h>
#include <sys/file.h>
#include <ufs/ufs/quota.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
/*
* Structure associated with user cacheing.
*/
struct uidinfo {
struct uidinfo *ui_next;
struct uidinfo **ui_prev;
uid_t ui_uid;
long ui_proccnt;
} **uihashtbl;
u_long uihash; /* size of hash table - 1 */
#define UIHASH(uid) ((uid) & uihash)
/*
* Allocate a hash table.
*/
usrinfoinit()
{
uihashtbl = hashinit(maxproc / 16, M_PROC, &uihash);
}
/*
* Change the count associated with number of processes
* a given user is using.
*/
int
chgproccnt(uid, diff)
uid_t uid;
int diff;
{
register struct uidinfo **uipp, *uip, *uiq;
uipp = &uihashtbl[UIHASH(uid)];
for (uip = *uipp; uip; uip = uip->ui_next)
if (uip->ui_uid == uid)
break;
if (uip) {
uip->ui_proccnt += diff;
if (uip->ui_proccnt > 0)
return (uip->ui_proccnt);
if (uip->ui_proccnt < 0)
panic("chgproccnt: procs < 0");
if (uiq = uip->ui_next)
uiq->ui_prev = uip->ui_prev;
*uip->ui_prev = uiq;
FREE(uip, M_PROC);
return (0);
}
if (diff <= 0) {
if (diff == 0)
return(0);
panic("chgproccnt: lost user");
}
MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
if (uiq = *uipp)
uiq->ui_prev = &uip->ui_next;
uip->ui_next = uiq;
uip->ui_prev = uipp;
*uipp = uip;
uip->ui_uid = uid;
uip->ui_proccnt = diff;
return (diff);
}
/*
* Is p an inferior of the current process?
*/
inferior(p)
register struct proc *p;
{
for (; p != curproc; p = p->p_pptr)
if (p->p_pid == 0)
return (0);
return (1);
}
/*
* Locate a process by number
*/
struct proc *
pfind(pid)
register pid;
{
register struct proc *p = pidhash[PIDHASH(pid)];
for (; p; p = p->p_hash)
if (p->p_pid == pid)
return (p);
return ((struct proc *)0);
}
/*
* Locate a process group by number
*/
struct pgrp *
pgfind(pgid)
register pid_t pgid;
{
register struct pgrp *pgrp = pgrphash[PIDHASH(pgid)];
for (; pgrp; pgrp = pgrp->pg_hforw)
if (pgrp->pg_id == pgid)
return (pgrp);
return ((struct pgrp *)0);
}
/*
* Move p to a new or existing process group (and session)
*/
enterpgrp(p, pgid, mksess)
register struct proc *p;
pid_t pgid;
int mksess;
{
register struct pgrp *pgrp = pgfind(pgid);
register struct proc **pp;
register struct proc *cp;
int n;
#ifdef DIAGNOSTIC
if (pgrp && mksess) /* firewalls */
panic("enterpgrp: setsid into non-empty pgrp");
if (SESS_LEADER(p))
panic("enterpgrp: session leader attempted setpgrp");
#endif
if (pgrp == NULL) {
pid_t savepid = p->p_pid;
struct proc *np;
/*
* new process group
*/
#ifdef DIAGNOSTIC
if (p->p_pid != pgid)
panic("enterpgrp: new pgrp and pid != pgid");
#endif
MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
M_WAITOK);
if ((np = pfind(savepid)) == NULL || np != p)
return (ESRCH);
if (mksess) {
register struct session *sess;
/*
* new session
*/
MALLOC(sess, struct session *, sizeof(struct session),
M_SESSION, M_WAITOK);
sess->s_leader = p;
sess->s_count = 1;
sess->s_ttyvp = NULL;
sess->s_ttyp = NULL;
bcopy(p->p_session->s_login, sess->s_login,
sizeof(sess->s_login));
p->p_flag &= ~SCTTY;
pgrp->pg_session = sess;
#ifdef DIAGNOSTIC
if (p != curproc)
panic("enterpgrp: mksession and p != curproc");
#endif
} else {
pgrp->pg_session = p->p_session;
pgrp->pg_session->s_count++;
}
pgrp->pg_id = pgid;
pgrp->pg_hforw = pgrphash[n = PIDHASH(pgid)];
pgrphash[n] = pgrp;
pgrp->pg_jobc = 0;
pgrp->pg_mem = NULL;
} else if (pgrp == p->p_pgrp)
return (0);
/*
* Adjust eligibility of affected pgrps to participate in job control.
* Increment eligibility counts before decrementing, otherwise we
* could reach 0 spuriously during the first call.
*/
fixjobc(p, pgrp, 1);
fixjobc(p, p->p_pgrp, 0);
/*
* unlink p from old process group
*/
for (pp = &p->p_pgrp->pg_mem; *pp; pp = &(*pp)->p_pgrpnxt) {
if (*pp == p) {
*pp = p->p_pgrpnxt;
break;
}
}
#ifdef DIAGNOSTIC
if (pp == NULL)
panic("enterpgrp: can't find p on old pgrp");
#endif
/*
* delete old if empty
*/
if (p->p_pgrp->pg_mem == 0)
pgdelete(p->p_pgrp);
/*
* link into new one
*/
p->p_pgrp = pgrp;
p->p_pgrpnxt = pgrp->pg_mem;
pgrp->pg_mem = p;
return (0);
}
/*
* remove process from process group
*/
leavepgrp(p)
register struct proc *p;
{
register struct proc **pp = &p->p_pgrp->pg_mem;
for (; *pp; pp = &(*pp)->p_pgrpnxt) {
if (*pp == p) {
*pp = p->p_pgrpnxt;
break;
}
}
#ifdef DIAGNOSTIC
if (pp == NULL)
panic("leavepgrp: can't find p in pgrp");
#endif
if (!p->p_pgrp->pg_mem)
pgdelete(p->p_pgrp);
p->p_pgrp = 0;
return (0);
}
/*
* delete a process group
*/
pgdelete(pgrp)
register struct pgrp *pgrp;
{
register struct pgrp **pgp = &pgrphash[PIDHASH(pgrp->pg_id)];
if (pgrp->pg_session->s_ttyp != NULL &&
pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
pgrp->pg_session->s_ttyp->t_pgrp = NULL;
for (; *pgp; pgp = &(*pgp)->pg_hforw) {
if (*pgp == pgrp) {
*pgp = pgrp->pg_hforw;
break;
}
}
#ifdef DIAGNOSTIC
if (pgp == NULL)
panic("pgdelete: can't find pgrp on hash chain");
#endif
if (--pgrp->pg_session->s_count == 0)
FREE(pgrp->pg_session, M_SESSION);
FREE(pgrp, M_PGRP);
}
static void orphanpg();
/*
* Adjust pgrp jobc counters when specified process changes process group.
* We count the number of processes in each process group that "qualify"
* the group for terminal job control (those with a parent in a different
* process group of the same session). If that count reaches zero, the
* process group becomes orphaned. Check both the specified process'
* process group and that of its children.
* entering == 0 => p is leaving specified group.
* entering == 1 => p is entering specified group.
*/
fixjobc(p, pgrp, entering)
register struct proc *p;
register struct pgrp *pgrp;
int entering;
{
register struct pgrp *hispgrp;
register struct session *mysession = pgrp->pg_session;
/*
* Check p's parent to see whether p qualifies its own process
* group; if so, adjust count for p's process group.
*/
if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
hispgrp->pg_session == mysession)
if (entering)
pgrp->pg_jobc++;
else if (--pgrp->pg_jobc == 0)
orphanpg(pgrp);
/*
* Check this process' children to see whether they qualify
* their process groups; if so, adjust counts for children's
* process groups.
*/
for (p = p->p_cptr; p; p = p->p_osptr)
if ((hispgrp = p->p_pgrp) != pgrp &&
hispgrp->pg_session == mysession &&
p->p_stat != SZOMB)
if (entering)
hispgrp->pg_jobc++;
else if (--hispgrp->pg_jobc == 0)
orphanpg(hispgrp);
}
/*
* A process group has become orphaned;
* if there are any stopped processes in the group,
* hang-up all process in that group.
*/
static void
orphanpg(pg)
struct pgrp *pg;
{
register struct proc *p;
for (p = pg->pg_mem; p; p = p->p_pgrpnxt) {
if (p->p_stat == SSTOP) {
for (p = pg->pg_mem; p; p = p->p_pgrpnxt) {
psignal(p, SIGHUP);
psignal(p, SIGCONT);
}
return;
}
}
}
#ifdef debug
/* DEBUG */
pgrpdump()
{
register struct pgrp *pgrp;
register struct proc *p;
register i;
for (i=0; i<PIDHSZ; i++) {
if (pgrphash[i]) {
printf("\tindx %d\n", i);
for (pgrp=pgrphash[i]; pgrp; pgrp=pgrp->pg_hforw) {
printf("\tpgrp %x, pgid %d, sess %x, sesscnt %d, mem %x\n",
pgrp, pgrp->pg_id, pgrp->pg_session,
pgrp->pg_session->s_count, pgrp->pg_mem);
for (p=pgrp->pg_mem; p; p=p->p_pgrpnxt) {
printf("\t\tpid %d addr %x pgrp %x\n",
p->p_pid, p, p->p_pgrp);
}
}
}
}
}
#endif /* debug */