BBN-Vax-TCP/sys/sys1.c
/* sys1.c 4.12 81/04/28 */
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/map.h"
#include "../h/mtpr.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/proc.h"
#include "../h/buf.h"
#include "../h/reg.h"
#include "../h/inode.h"
#include "../h/seg.h"
#include "../h/acct.h"
#include "/usr/include/wait.h"
#include "../h/pte.h"
#include "../h/vm.h"
#include "../h/text.h"
#include "../h/psl.h"
#include "../h/vlimit.h"
#include "../h/file.h"
/*
* exec system call, with and without environments.
*/
struct execa {
char *fname;
char **argp;
char **envp;
};
exec()
{
((struct execa *)u.u_ap)->envp = NULL;
exece();
}
exece()
{
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[DIRSIZ];
char cfarg[SHSIZE];
if ((ip = namei(uchar, 0)) == 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_base = (caddr_t)&u.u_exdata;
u.u_count = sizeof(u.u_exdata);
u.u_offset = 0;
u.u_segflg = 1;
readi(ip);
u.u_segflg = 0;
if(u.u_error)
goto bad;
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;
}
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_dbuf, (caddr_t)cfname, DIRSIZ);
indir = 1;
iput(ip);
ip = namei(schar, 0);
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, 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&BMASK) == 0) {
if (bp)
bdwrite(bp);
bp = getblk(argdev,
(daddr_t)(dbtofsb(bno)+(nc>>BSHIFT)));
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)
bcopy((caddr_t)cfname, (caddr_t)u.u_dbuf, DIRSIZ);
getxfile(ip, nc + (na+4)*NBPW, uid, gid);
if (u.u_error) {
badarg:
for (c = 0; c < nc; c += BSIZE)
if (bp = baddr(argdev, dbtofsb(bno)+(c>>BSHIFT))) {
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&BMASK) == 0) {
if (bp)
brelse(bp);
bp = bread(argdev,
(daddr_t)(dbtofsb(bno)+(nc>>BSHIFT)));
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);
(void) suword((caddr_t)ucp, 0);
setregs();
bad:
if (bp)
brelse(bp);
if (bno)
rmfree(argmap, 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_inode == ip && (fp->f_flag&FWRITE)) {
u.u_error = ETXTBSY;
goto bad;
}
}
/*
* find text and data sizes
* try them out for possible
* exceed of max sizes
*/
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;
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.
*/
u.u_prof.pr_scale = 0;
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) {
/*
* Read in data segment.
*/
u.u_base = (char *)ctob(ts);
u.u_offset = sizeof(u.u_exdata)+u.u_exdata.ux_tsize;
u.u_count = u.u_exdata.ux_dsize;
readi(ip);
}
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,
1 + ts/CLSIZE, (int)btoc(u.u_exdata.ux_dsize));
/* THIS SHOULD BE DONE AT A LOWER LEVEL, IF AT ALL */
mtpr(TBIA, 0);
/*
* set SUID/SGID protections, if no tracing
*/
if ((u.u_procp->p_flag&STRC)==0) {
#ifndef MELB
if(u.u_uid != 0)
#endif
{
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[0], 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_siga1 &= ~sigmask;
if ((int)*rp & 2)
u.u_procp->p_siga1 |= sigmask;
else
u.u_procp->p_siga1 &= ~sigmask;
(void) spl0();
continue;
}
}
/*
for(rp = &u.u_ar0[0]; rp < &u.u_ar0[16];)
*rp++ = 0;
*/
u.u_ar0[PC] = u.u_exdata.ux_entloc + 2; /* skip over entry mask */
for(i=0; i<NOFILE; i++) {
if (u.u_pofile[i]&EXCLOSE) {
closef(u.u_ofile[i]);
u.u_ofile[i] = NULL;
u.u_pofile[i] &= ~EXCLOSE;
}
}
/*
* Remember file name for accounting.
*/
u.u_acflag &= ~AFORK;
bcopy((caddr_t)u.u_dbuf, (caddr_t)u.u_comm, DIRSIZ);
}
/*
* 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 struct file *f;
register int x;
#ifdef PGINPROF
vmsizmon();
#endif
p = u.u_procp;
p->p_flag &= ~(STRC|SULOCK);
p->p_flag |= SWEXIT;
p->p_clktim = 0;
(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;
/*
* 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++) {
f = u.u_ofile[i];
u.u_ofile[i] = NULL;
closef(f);
}
plock(u.u_cdir);
iput(u.u_cdir);
if (u.u_rdir) {
plock(u.u_rdir);
iput(u.u_rdir);
}
u.u_limit[LIM_FSIZE] = INFINITY;
acct();
vrelpt(u.u_procp);
vrelu(u.u_procp, 0);
multprog--;
/* spl7(); /* clock will get mad because of overlaying */
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:
((struct xproc *)p)->xp_xstat = rv; /* overlay */
((struct xproc *)p)->xp_vm = u.u_vm; /* overlay */
vmsadd(&((struct xproc *)p)->xp_vm, &u.u_cvm);
for(q = proc; q < procNPROC; q++)
if(q->p_pptr == p) {
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,
* and set SDETACH bit on procs.
*/
(void) spgrp(q, -1);
}
wakeup((caddr_t)p->p_pptr);
psignal(p->p_pptr, SIGCHLD);
swtch();
}
wait()
{
struct vtimes vm;
struct vtimes *vp;
if ((u.u_ar0[PS] & PSL_ALLCC) != PSL_ALLCC) {
wait1(0, (struct vtimes *)0);
return;
}
vp = (struct vtimes *)u.u_ar0[R1];
wait1(u.u_ar0[R0], &vm);
if (u.u_error)
return;
(void) copyout((caddr_t)&vm, (caddr_t)vp, sizeof (struct vtimes));
}
/*
* 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, vp)
register options;
struct vtimes *vp;
{
register f;
register struct proc *p;
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 = ((struct xproc *)p)->xp_xstat;
((struct xproc *)p)->xp_xstat = 0;
if (vp)
*vp = ((struct xproc *)p)->xp_vm;
vmsadd(&u.u_cvm, &((struct xproc *)p)->xp_vm);
((struct xproc *)p)->xp_vm = zvms;
p->p_stat = NULL;
p->p_pid = 0;
p->p_ppid = 0;
p->p_pptr = 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;
}
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;
}
}
if (f==0) {
u.u_error = ECHILD;
return;
}
if (options&WNOHANG) {
u.u_r.r_val1 = 0;
return;
}
if ((u.u_procp->p_flag&SNUSIG) && setjmp(u.u_qsav)) {
u.u_eosys = RESTARTSYS;
return;
}
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;
register a;
a = 0;
p2 = NULL;
for(p1 = proc; p1 < procNPROC; p1++) {
if (p1->p_stat==NULL && p2==NULL)
p2 = p1;
else {
if (p1->p_uid==u.u_uid && p1->p_stat!=NULL)
a++;
}
}
/*
* 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");
if (p2==NULL || (u.u_uid!=0 && (p2==procNPROC-1 || a>MAXUPRC))) {
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;
u.u_acflag = AFORK;
return;
}
u.u_r.r_val1 = p2->p_pid;
out:
u.u_r.r_val2 = 0;
}
/*
* break system call.
* -- bad planning: "break" is a dirty word in C.
*/
sbreak()
{
struct a {
char *nsiz;
};
register int n, d;
/*
* set n to new data size
* set d to new-old
*/
n = btoc(((struct a *)u.u_ap)->nsiz);
if (!u.u_sep)
n -= ctos(u.u_tsize) * stoc(1);
if (n < 0)
n = 0;
d = clrnd(n - u.u_dsize);
if (ctob(u.u_dsize+d) > u.u_limit[LIM_DATA]) {
u.u_error = ENOMEM;
return;
}
if (chksize(u.u_tsize, u.u_dsize+d, u.u_ssize))
return;
if (swpexpand(u.u_dsize+d, u.u_ssize, &u.u_dmap, &u.u_smap)==0)
return;
expand(d, P0BR);
}