4.1cBSD/a/sys/sys/kern_process.c
/* kern_process.c 4.59 83/02/16 */
#include "../machine/reg.h"
#include "../machine/pte.h"
#include "../machine/psl.h"
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/map.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/kernel.h"
#include "../h/proc.h"
#include "../h/buf.h"
#include "../h/inode.h"
#include "../h/seg.h"
#include "../h/acct.h"
#include "../h/wait.h"
#include "../h/vm.h"
#include "../h/text.h"
#include "../h/file.h"
#include "../h/quota.h"
#include "../h/descrip.h"
#include "../h/uio.h"
#include "../h/mbuf.h"
#include "../h/nami.h"
gethostid()
{
u.u_r.r_val1 = hostid;
}
sethostid()
{
struct a {
int hostid;
} *uap = (struct a *)u.u_ap;
if (suser())
hostid = uap->hostid;
}
gethostname()
{
register struct a {
char *hostname;
int len;
} *uap = (struct a *)u.u_ap;
register u_int len;
len = uap->len;
if (len > hostnamelen)
len = hostnamelen;
u.u_error = copyout((caddr_t)hostname, (caddr_t)uap->hostname, len);
}
sethostname()
{
register struct a {
char *hostname;
u_int len;
} *uap = (struct a *)u.u_ap;
if (!suser())
return;
if (uap->len > sizeof (hostname) - 1) {
u.u_error = EINVAL;
return;
}
hostnamelen = uap->len;
u.u_error = copyin((caddr_t)uap->hostname, hostname, uap->len);
hostname[hostnamelen] = 0;
}
/*
* exec system call, with and without environments.
*/
struct execa {
char *fname;
char **argp;
char **envp;
};
execv()
{
((struct execa *)u.u_ap)->envp = NULL;
execve();
}
execve()
{
register nc;
register char *cp;
register struct buf *bp;
register struct execa *uap;
int na, ne, ucp, ap, c;
int indir, uid, gid;
char *sharg;
struct inode *ip;
swblk_t bno;
char cfname[MAXNAMLEN + 1];
char cfarg[SHSIZE];
int resid;
if ((ip = namei(uchar, LOOKUP, 1)) == NULL)
return;
bno = 0;
bp = 0;
indir = 0;
uid = u.u_uid;
gid = u.u_gid;
if (ip->i_mode & ISUID)
uid = ip->i_uid;
if (ip->i_mode & ISGID)
gid = ip->i_gid;
again:
if (access(ip, IEXEC))
goto bad;
if ((u.u_procp->p_flag&STRC) && access(ip, IREAD))
goto bad;
if ((ip->i_mode & IFMT) != IFREG ||
(ip->i_mode & (IEXEC|(IEXEC>>3)|(IEXEC>>6))) == 0) {
u.u_error = EACCES;
goto bad;
}
/*
* Read in first few bytes of file for segment sizes, ux_mag:
* 407 = plain executable
* 410 = RO text
* 413 = demand paged RO text
* Also an ASCII line beginning with #! is
* the file name of a ``shell'' and arguments may be prepended
* to the argument list if given here.
*
* SHELL NAMES ARE LIMITED IN LENGTH.
*
* ONLY ONE ARGUMENT MAY BE PASSED TO THE SHELL FROM
* THE ASCII LINE.
*/
u.u_exdata.ux_shell[0] = 0; /* for zero length files */
u.u_error = rdwri(UIO_READ, ip, (caddr_t)&u.u_exdata, sizeof (u.u_exdata),
0, 1, &resid);
if (u.u_error)
goto bad;
u.u_count = resid;
#ifndef lint
if (u.u_count > sizeof(u.u_exdata) - sizeof(u.u_exdata.Ux_A) &&
u.u_exdata.ux_shell[0] != '#') {
u.u_error = ENOEXEC;
goto bad;
}
#endif
switch (u.u_exdata.ux_mag) {
case 0407:
u.u_exdata.ux_dsize += u.u_exdata.ux_tsize;
u.u_exdata.ux_tsize = 0;
break;
case 0413:
case 0410:
if (u.u_exdata.ux_tsize == 0) {
u.u_error = ENOEXEC;
goto bad;
}
break;
default:
if (u.u_exdata.ux_shell[0] != '#' ||
u.u_exdata.ux_shell[1] != '!' ||
indir) {
u.u_error = ENOEXEC;
goto bad;
}
cp = &u.u_exdata.ux_shell[2]; /* skip "#!" */
while (cp < &u.u_exdata.ux_shell[SHSIZE]) {
if (*cp == '\t')
*cp = ' ';
else if (*cp == '\n') {
*cp = '\0';
break;
}
cp++;
}
if (*cp != '\0') {
u.u_error = ENOEXEC;
goto bad;
}
cp = &u.u_exdata.ux_shell[2];
while (*cp == ' ')
cp++;
u.u_dirp = cp;
while (*cp && *cp != ' ')
cp++;
sharg = NULL;
if (*cp) {
*cp++ = '\0';
while (*cp == ' ')
cp++;
if (*cp) {
bcopy((caddr_t)cp, (caddr_t)cfarg, SHSIZE);
sharg = cfarg;
}
}
bcopy((caddr_t)u.u_dent.d_name, (caddr_t)cfname,
(unsigned)(u.u_dent.d_namlen + 1));
indir = 1;
iput(ip);
ip = namei(schar, LOOKUP, 1);
if (ip == NULL)
return;
goto again;
}
/*
* Collect arguments on "file" in swap space.
*/
na = 0;
ne = 0;
nc = 0;
uap = (struct execa *)u.u_ap;
if ((bno = rmalloc(argmap, (long)ctod(clrnd((int)btoc(NCARGS))))) == 0) {
swkill(u.u_procp, "exece");
goto bad;
}
if (bno % CLSIZE)
panic("execa rmalloc");
if (uap->argp) for (;;) {
ap = NULL;
if (indir && (na == 1 || na == 2 && sharg))
ap = (int)uap->fname;
else if (uap->argp) {
ap = fuword((caddr_t)uap->argp);
uap->argp++;
}
if (ap==NULL && uap->envp) {
uap->argp = NULL;
if ((ap = fuword((caddr_t)uap->envp)) == NULL)
break;
uap->envp++;
ne++;
}
if (ap == NULL)
break;
na++;
if (ap == -1)
u.u_error = EFAULT;
do {
if (nc >= NCARGS-1)
u.u_error = E2BIG;
if (indir && na == 2 && sharg != NULL)
c = *sharg++ & 0377;
else if ((c = fubyte((caddr_t)ap++)) < 0)
u.u_error = EFAULT;
if (u.u_error) {
if (bp)
brelse(bp);
bp = 0;
goto badarg;
}
if (nc % (CLSIZE*NBPG) == 0) {
if (bp)
bdwrite(bp);
bp = getblk(argdev, bno + ctod(nc / NBPG),
CLSIZE*NBPG);
cp = bp->b_un.b_addr;
}
nc++;
*cp++ = c;
} while (c > 0);
}
if (bp)
bdwrite(bp);
bp = 0;
nc = (nc + NBPW-1) & ~(NBPW-1);
if (indir) {
u.u_dent.d_namlen = strlen(cfname);
bcopy((caddr_t)cfname, (caddr_t)u.u_dent.d_name,
(unsigned)(u.u_dent.d_namlen + 1));
}
getxfile(ip, nc + (na+4)*NBPW, uid, gid);
if (u.u_error) {
badarg:
for (c = 0; c < nc; c += CLSIZE*NBPG) {
bp = baddr(argdev, bno + ctod(c / NBPG), CLSIZE*NBPG);
if (bp) {
bp->b_flags |= B_AGE; /* throw away */
bp->b_flags &= ~B_DELWRI; /* cancel io */
brelse(bp);
bp = 0;
}
}
goto bad;
}
/*
* copy back arglist
*/
ucp = USRSTACK - nc - NBPW;
ap = ucp - na*NBPW - 3*NBPW;
u.u_ar0[SP] = ap;
(void) suword((caddr_t)ap, na-ne);
nc = 0;
for (;;) {
ap += NBPW;
if (na==ne) {
(void) suword((caddr_t)ap, 0);
ap += NBPW;
}
if (--na < 0)
break;
(void) suword((caddr_t)ap, ucp);
do {
if (nc % (CLSIZE*NBPG) == 0) {
if (bp)
brelse(bp);
bp = bread(argdev, bno + ctod(nc / NBPG),
CLSIZE*NBPG);
bp->b_flags |= B_AGE; /* throw away */
bp->b_flags &= ~B_DELWRI; /* cancel io */
cp = bp->b_un.b_addr;
}
(void) subyte((caddr_t)ucp++, (c = *cp++));
nc++;
} while(c&0377);
}
(void) suword((caddr_t)ap, 0);
setregs();
bad:
if (bp)
brelse(bp);
if (bno)
rmfree(argmap, (long)ctod(clrnd((int) btoc(NCARGS))), bno);
iput(ip);
}
/*
* Read in and set up memory for executed file.
*/
getxfile(ip, nargc, uid, gid)
register struct inode *ip;
{
register size_t ts, ds, ss;
int pagi;
if (u.u_exdata.ux_mag == 0413)
pagi = SPAGI;
else
pagi = 0;
if (u.u_exdata.ux_tsize!=0 && (ip->i_flag&ITEXT)==0 &&
ip->i_count!=1) {
register struct file *fp;
for (fp = file; fp < fileNFILE; fp++) {
if (fp->f_type == DTYPE_FILE &&
fp->f_count > 0 &&
fp->f_inode == ip && (fp->f_flag&FWRITE)) {
u.u_error = ETXTBSY;
goto bad;
}
}
}
/*
* Compute text and data sizes and make sure not too large.
*/
ts = clrnd(btoc(u.u_exdata.ux_tsize));
ds = clrnd(btoc((u.u_exdata.ux_dsize+u.u_exdata.ux_bsize)));
ss = clrnd(SSIZE + btoc(nargc));
if (chksize(ts, ds, ss))
goto bad;
/*
* Make sure enough space to start process.
*/
u.u_cdmap = zdmap;
u.u_csmap = zdmap;
if (swpexpand(ds, ss, &u.u_cdmap, &u.u_csmap) == NULL)
goto bad;
/*
* At this point, committed to the new image!
* Release virtual memory resources of old process, and
* initialize the virtual memory of the new process.
* If we resulted from vfork(), instead wakeup our
* parent who will set SVFDONE when he has taken back
* our resources.
*/
if ((u.u_procp->p_flag & SVFORK) == 0)
vrelvm();
else {
u.u_procp->p_flag &= ~SVFORK;
u.u_procp->p_flag |= SKEEP;
wakeup((caddr_t)u.u_procp);
while ((u.u_procp->p_flag & SVFDONE) == 0)
sleep((caddr_t)u.u_procp, PZERO - 1);
u.u_procp->p_flag &= ~(SVFDONE|SKEEP);
}
u.u_procp->p_flag &= ~(SPAGI|SSEQL|SUANOM|SNUSIG);
u.u_procp->p_flag |= pagi;
u.u_dmap = u.u_cdmap;
u.u_smap = u.u_csmap;
vgetvm(ts, ds, ss);
if (pagi == 0)
u.u_error =
rdwri(UIO_READ, ip,
(char *)ctob(dptov(u.u_procp, 0)),
(int)u.u_exdata.ux_dsize,
(int)(sizeof(u.u_exdata)+u.u_exdata.ux_tsize),
0, (int *)0);
xalloc(ip, pagi);
if (pagi && u.u_procp->p_textp)
vinifod((struct fpte *)dptopte(u.u_procp, 0),
PG_FTEXT, u.u_procp->p_textp->x_iptr,
(long)(1 + ts/CLSIZE), (int)btoc(u.u_exdata.ux_dsize));
#ifdef vax
/* THIS SHOULD BE DONE AT A LOWER LEVEL, IF AT ALL */
#include "../vax/mtpr.h" /* XXX */
mtpr(TBIA, 0);
#endif
if (u.u_error)
swkill(u.u_procp, "i/o error mapping pages");
/*
* set SUID/SGID protections, if no tracing
*/
if ((u.u_procp->p_flag&STRC)==0) {
u.u_uid = uid;
u.u_procp->p_uid = uid;
u.u_gid = gid;
} else
psignal(u.u_procp, SIGTRAP);
u.u_tsize = ts;
u.u_dsize = ds;
u.u_ssize = ss;
bad:
return;
}
/*
* Clear registers on exec
*/
setregs()
{
register int (**rp)();
register i;
long sigmask;
for (rp = &u.u_signal[1], sigmask = 1L; rp < &u.u_signal[NSIG];
sigmask <<= 1, rp++) {
switch (*rp) {
case SIG_IGN:
case SIG_DFL:
case SIG_HOLD:
continue;
default:
/*
* Normal or deferring catch; revert to default.
*/
(void) spl6();
*rp = SIG_DFL;
if ((int)*rp & 1)
u.u_procp->p_siga0 |= sigmask;
else
u.u_procp->p_siga0 &= ~sigmask;
if ((int)*rp & 2)
u.u_procp->p_siga1 |= sigmask;
else
u.u_procp->p_siga1 &= ~sigmask;
(void) spl0();
continue;
}
}
#ifdef vax
/*
for (rp = &u.u_ar0[0]; rp < &u.u_ar0[16];)
*rp++ = 0;
*/
u.u_ar0[PC] = u.u_exdata.ux_entloc+2;
#endif
#ifdef sun
{ register struct regs *r = (struct regs *)u.u_ar0;
for (i = 0; i < 8; i++) {
r->r_dreg[i] = 0;
if (&r->r_areg[i] != &r->r_sp)
r->r_areg[i] = 0;
}
r->r_sr = PSL_USERSET;
r->r_pc = u.u_exdata.ux_entloc;
}
#endif
for (i=0; i<NOFILE; i++) {
if (u.u_pofile[i]&UF_EXCLOSE) {
closef(u.u_ofile[i], 1, u.u_pofile[i]);
u.u_ofile[i] = NULL;
u.u_pofile[i] = 0;
}
u.u_pofile[i] &= ~UF_MAPPED;
}
/*
* Remember file name for accounting.
*/
u.u_acflag &= ~AFORK;
bcopy((caddr_t)u.u_dent.d_name, (caddr_t)u.u_comm,
(unsigned)(u.u_dent.d_namlen + 1));
#ifdef sun
u.u_eosys = REALLYRETURN;
#endif
}
/*
* Exit system call: pass back caller's arg
*/
rexit()
{
register struct a {
int rval;
} *uap;
uap = (struct a *)u.u_ap;
exit((uap->rval & 0377) << 8);
}
/*
* Release resources.
* Save u. area for parent to look at.
* Enter zombie state.
* Wake up parent and init processes,
* and dispose of children.
*/
exit(rv)
{
register int i;
register struct proc *p, *q;
register int x;
struct mbuf *m = m_getclr(M_WAIT, MT_ZOMBIE);
#ifdef PGINPROF
vmsizmon();
#endif
p = u.u_procp;
p->p_flag &= ~(STRC|SULOCK);
p->p_flag |= SWEXIT;
(void) spl6();
if ((int)SIG_IGN & 1)
p->p_siga0 = ~0;
else
p->p_siga0 = 0;
if ((int)SIG_IGN & 2)
p->p_siga1 = ~0;
else
p->p_siga1 = 0;
(void) spl0();
p->p_cpticks = 0;
p->p_pctcpu = 0;
for (i=0; i<NSIG; i++)
u.u_signal[i] = SIG_IGN;
untimeout(realitexpire, (caddr_t)p);
/*
* Release virtual memory. If we resulted from
* a vfork(), instead give the resources back to
* the parent.
*/
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;
int p;
f = u.u_ofile[i];
u.u_ofile[i] = NULL;
p = u.u_pofile[i];
u.u_pofile[i] = 0;
closef(f, 1, p);
}
ilock(u.u_cdir);
iput(u.u_cdir);
if (u.u_rdir) {
ilock(u.u_rdir);
iput(u.u_rdir);
}
u.u_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
acct();
#ifdef QUOTA
qclean();
#endif
#ifdef sun
ctxfree(&u);
#endif
vrelpt(u.u_procp);
vrelu(u.u_procp, 0);
(void) spl5(); /* hack for mem alloc race XXX */
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");
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);
for (q = proc; q < procNPROC; q++)
if (q->p_pptr == p) {
if (q->p_osptr)
q->p_osptr->p_ysptr = q->p_ysptr;
if (q->p_ysptr)
q->p_ysptr->p_osptr = q->p_osptr;
if (proc[1].p_cptr)
proc[1].p_cptr->p_ysptr = q;
q->p_osptr = proc[1].p_cptr;
q->p_ysptr = NULL;
proc[1].p_cptr = q;
q->p_pptr = &proc[1];
q->p_ppid = 1;
wakeup((caddr_t)&proc[1]);
/*
* 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);
}
psignal(p->p_pptr, SIGCHLD);
wakeup((caddr_t)p->p_pptr);
swtch();
}
wait()
{
struct rusage ru, *rup;
if ((u.u_ar0[PS] & PSL_ALLCC) != PSL_ALLCC) {
u.u_error = wait1(0, (struct rusage *)0);
return;
}
rup = (struct rusage *)u.u_ar0[R1];
u.u_error = wait1(u.u_ar0[R0], &ru);
if (u.u_error)
return;
(void) copyout((caddr_t)&ru, (caddr_t)rup, sizeof (struct rusage));
}
#ifndef NOCOMPAT
#include "../h/vtimes.h"
owait()
{
struct rusage ru;
struct vtimes *vtp, avt;
if ((u.u_ar0[PS] & PSL_ALLCC) != PSL_ALLCC) {
u.u_error = wait1(0, (struct rusage *)0);
return;
}
vtp = (struct vtimes *)u.u_ar0[R1];
u.u_error = wait1(u.u_ar0[R0], &ru);
if (u.u_error)
return;
getvtimes(&ru, &avt);
(void) copyout((caddr_t)&avt, (caddr_t)vtp, sizeof (struct vtimes));
}
#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.
*/
wait1(options, ru)
register int options;
struct rusage *ru;
{
register f;
register struct proc *p, *q;
f = 0;
loop:
for (p = proc; p < procNPROC; p++)
if (p->p_pptr == u.u_procp) {
f++;
if (p->p_stat == SZOMB) {
u.u_r.r_val1 = p->p_pid;
u.u_r.r_val2 = p->p_xstat;
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;
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_siga0 = 0;
p->p_siga1 = 0;
p->p_pgrp = 0;
p->p_flag = 0;
p->p_wchan = 0;
p->p_cursig = 0;
return (0);
}
if (p->p_stat == SSTOP && (p->p_flag&SWTED)==0 &&
(p->p_flag&STRC || 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);
}
}
if (f == 0) {
return (ECHILD);
}
if (options&WNOHANG) {
u.u_r.r_val1 = 0;
return (0);
}
if ((u.u_procp->p_flag&SNUSIG) && setjmp(&u.u_qsave)) {
u.u_eosys = RESTARTSYS;
return (0);
}
sleep((caddr_t)u.u_procp, PWAIT);
goto loop;
}
/*
* fork system call.
*/
fork()
{
u.u_cdmap = zdmap;
u.u_csmap = zdmap;
if (swpexpand(u.u_dsize, u.u_ssize, &u.u_cdmap, &u.u_csmap) == 0) {
u.u_r.r_val2 = 0;
return;
}
fork1(0);
}
fork1(isvfork)
{
register struct proc *p1, *p2;
#ifndef QUOTA
register a;
a = 0;
#else
if (u.u_quota != NOQUOT && u.u_quota->q_plim &&
u.u_quota->q_cnt >= u.u_quota->q_plim) {
u.u_error = EPROCLIM;
return;
}
#endif
p2 = NULL;
for (p1 = proc; p1 < procNPROC; p1++) {
#ifdef QUOTA
if (p1->p_stat == NULL) {
p2 = p1;
break;
}
#else
if (p1->p_stat==NULL && p2==NULL)
p2 = p1;
else {
if (p1->p_uid==u.u_uid && p1->p_stat!=NULL)
a++;
}
#endif
}
/*
* Disallow if
* No processes at all;
* not su and too many procs owned; or
* not su and would take last slot.
*/
if (p2==NULL)
tablefull("proc");
#ifdef QUOTA
if (p2==NULL || (u.u_uid!=0 && p2==procNPROC-1)) {
#else
if (p2==NULL || (u.u_uid!=0 && (p2==procNPROC-1 || a>MAXUPRC))) {
#endif
u.u_error = EAGAIN;
if (!isvfork) {
(void) vsexpand(0, &u.u_cdmap, 1);
(void) vsexpand(0, &u.u_csmap, 1);
}
goto out;
}
p1 = u.u_procp;
if (newproc(isvfork)) {
u.u_r.r_val1 = p1->p_pid;
u.u_r.r_val2 = 1; /* child */
u.u_start = time.tv_sec;
u.u_acflag = AFORK;
#ifdef QUOTA
u.u_qflags &= ~QUF_LOGIN;
#endif
return;
}
u.u_r.r_val1 = p2->p_pid;
out:
u.u_r.r_val2 = 0;
}
spgrp(top, npgrp)
register struct proc *top;
{
register struct proc *pp, *p;
int f = 0;
for (p = top; npgrp == -1 || u.u_uid == p->p_uid ||
!u.u_uid || inferior(p); p = pp) {
if (npgrp == -1) {
#define bit(a) (1<<(a-1))
p->p_sig &= ~(bit(SIGTSTP)|bit(SIGTTIN)|bit(SIGTTOU));
} else
p->p_pgrp = npgrp;
f++;
/*
* Search for children.
*/
for (pp = proc; pp < procNPROC; pp++)
if (pp->p_pptr == p)
goto cont;
/*
* Search for siblings.
*/
for (; p != top; p = p->p_pptr)
for (pp = p + 1; pp < procNPROC; pp++)
if (pp->p_pptr == p->p_pptr)
goto cont;
break;
cont:
;
}
return (f);
}
/*
* Is p an inferior of the current process?
*/
inferior(p)
register struct proc *p;
{
for (; p != u.u_procp; p = p->p_pptr)
if (p->p_ppid == 0)
return (0);
return (1);
}
struct proc *
pfind(pid)
int pid;
{
register struct proc *p;
for (p = &proc[pidhash[PIDHASH(pid)]]; p != &proc[0]; p = &proc[p->p_idhash])
if (p->p_pid == pid)
return (p);
return ((struct proc *)0);
}
/*
* Create a new process-- the internal version of
* sys fork.
* It returns 1 in the new process, 0 in the old.
*/
newproc(isvfork)
int isvfork;
{
register struct proc *p;
register struct proc *rpp, *rip;
register int n;
register struct file *fp;
p = NULL;
/*
* First, just locate a slot for a process
* and copy the useful info from this process into it.
* The panic "cannot happen" because fork has already
* checked for the existence of a slot.
*/
retry:
mpid++;
if (mpid >= 30000) {
mpid = 0;
goto retry;
}
for (rpp = proc; rpp < procNPROC; rpp++) {
if (rpp->p_stat == NULL && p==NULL)
p = rpp;
if (rpp->p_pid==mpid || rpp->p_pgrp==mpid)
goto retry;
}
if ((rpp = p) == NULL)
panic("no procs");
/*
* Make a proc table entry for the new process.
*/
rip = u.u_procp;
#ifdef QUOTA
(rpp->p_quota = rip->p_quota)->q_cnt++;
#endif
rpp->p_stat = SIDL;
timerclear(&rpp->p_realtimer.it_value);
rpp->p_flag = SLOAD | (rip->p_flag & (SPAGI|SNUSIG));
if (isvfork) {
rpp->p_flag |= SVFORK;
rpp->p_ndx = rip->p_ndx;
} else
rpp->p_ndx = rpp - proc;
rpp->p_uid = rip->p_uid;
rpp->p_pgrp = rip->p_pgrp;
rpp->p_nice = rip->p_nice;
rpp->p_textp = isvfork ? 0 : rip->p_textp;
rpp->p_pid = mpid;
rpp->p_ppid = rip->p_pid;
rpp->p_pptr = rip;
rpp->p_osptr = rip->p_cptr;
if (rip->p_cptr)
rip->p_cptr->p_ysptr = rpp;
rpp->p_ysptr = NULL;
rpp->p_cptr = NULL;
rip->p_cptr = rpp;
rpp->p_time = 0;
rpp->p_cpu = 0;
rpp->p_siga0 = rip->p_siga0;
rpp->p_siga1 = rip->p_siga1;
/* take along any pending signals, like stops? */
if (isvfork) {
rpp->p_tsize = rpp->p_dsize = rpp->p_ssize = 0;
rpp->p_szpt = clrnd(ctopt(UPAGES));
forkstat.cntvfork++;
forkstat.sizvfork += rip->p_dsize + rip->p_ssize;
} else {
rpp->p_tsize = rip->p_tsize;
rpp->p_dsize = rip->p_dsize;
rpp->p_ssize = rip->p_ssize;
rpp->p_szpt = rip->p_szpt;
forkstat.cntfork++;
forkstat.sizfork += rip->p_dsize + rip->p_ssize;
}
rpp->p_rssize = 0;
rpp->p_maxrss = rip->p_maxrss;
rpp->p_wchan = 0;
rpp->p_slptime = 0;
rpp->p_pctcpu = 0;
rpp->p_cpticks = 0;
n = PIDHASH(rpp->p_pid);
p->p_idhash = pidhash[n];
pidhash[n] = rpp - proc;
multprog++;
/*
* Increase reference counts on shared objects.
*/
for (n = 0; n < NOFILE; n++) {
fp = u.u_ofile[n];
if (fp == NULL)
continue;
fp->f_count++;
if (u.u_pofile[n]&UF_SHLOCK)
fp->f_inode->i_shlockc++;
if (u.u_pofile[n]&UF_EXLOCK)
fp->f_inode->i_exlockc++;
}
u.u_cdir->i_count++;
if (u.u_rdir)
u.u_rdir->i_count++;
/*
* Partially simulate the environment
* of the new process so that when it is actually
* created (by copying) it will look right.
* This begins the section where we must prevent the parent
* from being swapped.
*/
rip->p_flag |= SKEEP;
if (procdup(rpp, isvfork))
return (1);
/*
* Make child runnable and add to run queue.
*/
(void) spl6();
rpp->p_stat = SRUN;
setrq(rpp);
(void) spl0();
/*
* Cause child to take a non-local goto as soon as it runs.
* On older systems this was done with SSWAP bit in proc
* table; on VAX we use u.u_pcb.pcb_sswap so don't need
* to do rpp->p_flag |= SSWAP. Actually do nothing here.
*/
/* rpp->p_flag |= SSWAP; */
/*
* Now can be swapped.
*/
rip->p_flag &= ~SKEEP;
/*
* If vfork make chain from parent process to child
* (where virtal memory is temporarily). Wait for
* child to finish, steal virtual memory back,
* and wakeup child to let it die.
*/
if (isvfork) {
u.u_procp->p_xlink = rpp;
u.u_procp->p_flag |= SNOVM;
while (rpp->p_flag & SVFORK)
sleep((caddr_t)rpp, PZERO - 1);
if ((rpp->p_flag & SLOAD) == 0)
panic("newproc vfork");
uaccess(rpp, Vfmap, &vfutl);
u.u_procp->p_xlink = 0;
vpassvm(rpp, u.u_procp, &vfutl, &u, Vfmap);
u.u_procp->p_flag &= ~SNOVM;
rpp->p_ndx = rpp - proc;
rpp->p_flag |= SVFDONE;
wakeup((caddr_t)rpp);
}
/*
* 0 return means parent.
*/
return (0);
}