[unix-history] / usr / src / sys / kern / kern_exec.c

/*	kern_exec.c	4.1	83/05/27	*/

#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/vm.h"
#include "../h/text.h"
#include "../h/file.h"
#include "../h/uio.h"
#include "../h/nami.h"
#include "../h/acct.h"

/*
 * 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[MAXCOMLEN + 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;
			}
		}
		if (u.u_dent.d_namlen > MAXCOMLEN)
			u.u_dent.d_namlen = MAXCOMLEN;
		bcopy((caddr_t)u.u_dent.d_name, (caddr_t)cfname,
		    (unsigned)(u.u_dent.d_namlen + 1));
		cfname[MAXCOMLEN] = 0;
		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;
	int nargc, uid, gid;
{
	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_INODE &&
			    fp->f_count > 0 &&
			    (struct inode *)fp->f_data == 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((unsigned)ts, (unsigned)ds, (unsigned)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 int i, sigmask;

	for (rp = &u.u_signal[1], sigmask = 1; 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], 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
}
Commit	Line	Data
28db9b87 SL	1	/* kern_exec.c 4.1 83/05/27 */
	2
	3	#include "../machine/reg.h"
	4	#include "../machine/pte.h"
	5	#include "../machine/psl.h"
	6
	7	#include "../h/param.h"
	8	#include "../h/systm.h"
	9	#include "../h/map.h"
	10	#include "../h/dir.h"
	11	#include "../h/user.h"
	12	#include "../h/kernel.h"
	13	#include "../h/proc.h"
	14	#include "../h/buf.h"
	15	#include "../h/inode.h"
	16	#include "../h/seg.h"
	17	#include "../h/vm.h"
	18	#include "../h/text.h"
	19	#include "../h/file.h"
	20	#include "../h/uio.h"
	21	#include "../h/nami.h"
	22	#include "../h/acct.h"
	23
	24	/*
	25	* exec system call, with and without environments.
	26	*/
	27	struct execa {
	28	char *fname;
	29	char **argp;
	30	char **envp;
	31	};
	32
	33	execv()
	34	{
	35	((struct execa *)u.u_ap)->envp = NULL;
	36	execve();
	37	}
	38
	39	execve()
	40	{
	41	register nc;
	42	register char *cp;
	43	register struct buf *bp;
	44	register struct execa *uap;
	45	int na, ne, ucp, ap, c;
	46	int indir, uid, gid;
	47	char *sharg;
	48	struct inode *ip;
	49	swblk_t bno;
	50	char cfname[MAXCOMLEN + 1];
	51	char cfarg[SHSIZE];
	52	int resid;
	53
	54	if ((ip = namei(uchar, LOOKUP, 1)) == NULL)
	55	return;
	56	bno = 0;
	57	bp = 0;
	58	indir = 0;
	59	uid = u.u_uid;
	60	gid = u.u_gid;
	61	if (ip->i_mode & ISUID)
	62	uid = ip->i_uid;
	63	if (ip->i_mode & ISGID)
	64	gid = ip->i_gid;
65
66	again:
67	if (access(ip, IEXEC))
68	goto bad;
69	if ((u.u_procp->p_flag&STRC) && access(ip, IREAD))
70	goto bad;
71	if ((ip->i_mode & IFMT) != IFREG \|\|
72	(ip->i_mode & (IEXEC\|(IEXEC>>3)\|(IEXEC>>6))) == 0) {
73	u.u_error = EACCES;
74	goto bad;
75	}
76
77	/*
78	* Read in first few bytes of file for segment sizes, ux_mag:
79	* 407 = plain executable
80	* 410 = RO text
81	* 413 = demand paged RO text
82	* Also an ASCII line beginning with #! is
83	* the file name of a ``shell'' and arguments may be prepended
84	* to the argument list if given here.
85	*
86	* SHELL NAMES ARE LIMITED IN LENGTH.
87	*
88	* ONLY ONE ARGUMENT MAY BE PASSED TO THE SHELL FROM
89	* THE ASCII LINE.
90	*/
91	u.u_exdata.ux_shell[0] = 0; /* for zero length files */
92	u.u_error = rdwri(UIO_READ, ip, (caddr_t)&u.u_exdata, sizeof (u.u_exdata),
93	0, 1, &resid);
94	if (u.u_error)
95	goto bad;
96	u.u_count = resid;
97	#ifndef lint
98	if (u.u_count > sizeof(u.u_exdata) - sizeof(u.u_exdata.Ux_A) &&
99	u.u_exdata.ux_shell[0] != '#') {
100	u.u_error = ENOEXEC;
101	goto bad;
102	}
103	#endif
104	switch (u.u_exdata.ux_mag) {
105
106	case 0407:
107	u.u_exdata.ux_dsize += u.u_exdata.ux_tsize;
108	u.u_exdata.ux_tsize = 0;
109	break;
110
111	case 0413:
112	case 0410:
113	if (u.u_exdata.ux_tsize == 0) {
114	u.u_error = ENOEXEC;
115	goto bad;
116	}
117	break;
118
119	default:
120	if (u.u_exdata.ux_shell[0] != '#' \|\|
121	u.u_exdata.ux_shell[1] != '!' \|\|
122	indir) {
123	u.u_error = ENOEXEC;
124	goto bad;
125	}
126	cp = &u.u_exdata.ux_shell[2]; /* skip "#!" */
127	while (cp < &u.u_exdata.ux_shell[SHSIZE]) {
128	if (*cp == '\t')
129	*cp = ' ';
130	else if (*cp == '\n') {
131	*cp = '\0';
132	break;
133	}
134	cp++;
135	}
136	if (*cp != '\0') {
137	u.u_error = ENOEXEC;
138	goto bad;
139	}
140	cp = &u.u_exdata.ux_shell[2];
141	while (*cp == ' ')
142	cp++;
143	u.u_dirp = cp;
144	while (cp && cp != ' ')
145	cp++;
146	sharg = NULL;
147	if (*cp) {
148	*cp++ = '\0';
149	while (*cp == ' ')
150	cp++;
151	if (*cp) {
152	bcopy((caddr_t)cp, (caddr_t)cfarg, SHSIZE);
153	sharg = cfarg;
154	}
155	}
156	if (u.u_dent.d_namlen > MAXCOMLEN)
157	u.u_dent.d_namlen = MAXCOMLEN;
158	bcopy((caddr_t)u.u_dent.d_name, (caddr_t)cfname,
159	(unsigned)(u.u_dent.d_namlen + 1));
160	cfname[MAXCOMLEN] = 0;
161	indir = 1;
162	iput(ip);
163	ip = namei(schar, LOOKUP, 1);
164	if (ip == NULL)
165	return;
166	goto again;
167	}
168
169	/*
170	* Collect arguments on "file" in swap space.
171	*/
172	na = 0;
173	ne = 0;
174	nc = 0;
175	uap = (struct execa *)u.u_ap;
176	if ((bno = rmalloc(argmap, (long)ctod(clrnd((int)btoc(NCARGS))))) == 0) {
177	swkill(u.u_procp, "exece");
178	goto bad;
179	}
180	if (bno % CLSIZE)
181	panic("execa rmalloc");
182	if (uap->argp) for (;;) {
183	ap = NULL;
184	if (indir && (na == 1 \|\| na == 2 && sharg))
185	ap = (int)uap->fname;
186	else if (uap->argp) {
187	ap = fuword((caddr_t)uap->argp);
188	uap->argp++;
189	}
190	if (ap==NULL && uap->envp) {
191	uap->argp = NULL;
192	if ((ap = fuword((caddr_t)uap->envp)) == NULL)
193	break;
194	uap->envp++;
195	ne++;
196	}
197	if (ap == NULL)
198	break;
199	na++;
200	if (ap == -1)
201	u.u_error = EFAULT;
202	do {
203	if (nc >= NCARGS-1)
204	u.u_error = E2BIG;
205	if (indir && na == 2 && sharg != NULL)
206	c = *sharg++ & 0377;
207	else if ((c = fubyte((caddr_t)ap++)) < 0)
208	u.u_error = EFAULT;
209	if (u.u_error) {
210	if (bp)
211	brelse(bp);
212	bp = 0;
213	goto badarg;
214	}
215	if (nc % (CLSIZE*NBPG) == 0) {
216	if (bp)
217	bdwrite(bp);
218	bp = getblk(argdev, bno + ctod(nc / NBPG),
219	CLSIZE*NBPG);
220	cp = bp->b_un.b_addr;
221	}
222	nc++;
223	*cp++ = c;
224	} while (c > 0);
225	}
226	if (bp)
227	bdwrite(bp);
228	bp = 0;
229	nc = (nc + NBPW-1) & ~(NBPW-1);
230	if (indir) {
231	u.u_dent.d_namlen = strlen(cfname);
232	bcopy((caddr_t)cfname, (caddr_t)u.u_dent.d_name,
233	(unsigned)(u.u_dent.d_namlen + 1));
234	}
235	getxfile(ip, nc + (na+4)*NBPW, uid, gid);
236	if (u.u_error) {
237	badarg:
238	for (c = 0; c < nc; c += CLSIZE*NBPG) {
239	bp = baddr(argdev, bno + ctod(c / NBPG), CLSIZE*NBPG);
240	if (bp) {
241	bp->b_flags \|= B_AGE; /* throw away */
242	bp->b_flags &= ~B_DELWRI; /* cancel io */
243	brelse(bp);
244	bp = 0;
245	}
246	}
247	goto bad;
248	}
249
250	/*
251	* copy back arglist
252	*/
253	ucp = USRSTACK - nc - NBPW;
254	ap = ucp - naNBPW - 3NBPW;
255	u.u_ar0[SP] = ap;
256	(void) suword((caddr_t)ap, na-ne);
257	nc = 0;
258	for (;;) {
259	ap += NBPW;
260	if (na==ne) {
261	(void) suword((caddr_t)ap, 0);
262	ap += NBPW;
263	}
264	if (--na < 0)
265	break;
266	(void) suword((caddr_t)ap, ucp);
267	do {
268	if (nc % (CLSIZE*NBPG) == 0) {
269	if (bp)
270	brelse(bp);
271	bp = bread(argdev, bno + ctod(nc / NBPG),
272	CLSIZE*NBPG);
273	bp->b_flags \|= B_AGE; /* throw away */
274	bp->b_flags &= ~B_DELWRI; /* cancel io */
275	cp = bp->b_un.b_addr;
276	}
277	(void) subyte((caddr_t)ucp++, (c = *cp++));
278	nc++;
279	} while(c&0377);
280	}
281	(void) suword((caddr_t)ap, 0);
282	setregs();
283	bad:
284	if (bp)
285	brelse(bp);
286	if (bno)
287	rmfree(argmap, (long)ctod(clrnd((int) btoc(NCARGS))), bno);
288	iput(ip);
289	}
290
291	/*
292	* Read in and set up memory for executed file.
293	*/
294	getxfile(ip, nargc, uid, gid)
295	register struct inode *ip;
296	int nargc, uid, gid;
297	{
298	register size_t ts, ds, ss;
299	int pagi;
300
301	if (u.u_exdata.ux_mag == 0413)
302	pagi = SPAGI;
303	else
304	pagi = 0;
305	if (u.u_exdata.ux_tsize!=0 && (ip->i_flag&ITEXT)==0 &&
306	ip->i_count!=1) {
307	register struct file *fp;
308
309	for (fp = file; fp < fileNFILE; fp++) {
310	if (fp->f_type == DTYPE_INODE &&
311	fp->f_count > 0 &&
312	(struct inode *)fp->f_data == ip &&
313	(fp->f_flag&FWRITE)) {
314	u.u_error = ETXTBSY;
315	goto bad;
316	}
317	}
318	}
319
320	/*
321	* Compute text and data sizes and make sure not too large.
322	*/
323	ts = clrnd(btoc(u.u_exdata.ux_tsize));
324	ds = clrnd(btoc((u.u_exdata.ux_dsize+u.u_exdata.ux_bsize)));
325	ss = clrnd(SSIZE + btoc(nargc));
326	if (chksize((unsigned)ts, (unsigned)ds, (unsigned)ss))
327	goto bad;
328
329	/*
330	* Make sure enough space to start process.
331	*/
332	u.u_cdmap = zdmap;
333	u.u_csmap = zdmap;
334	if (swpexpand(ds, ss, &u.u_cdmap, &u.u_csmap) == NULL)
335	goto bad;
336
337	/*
338	* At this point, committed to the new image!
339	* Release virtual memory resources of old process, and
340	* initialize the virtual memory of the new process.
341	* If we resulted from vfork(), instead wakeup our
342	* parent who will set SVFDONE when he has taken back
343	* our resources.
344	*/
345	if ((u.u_procp->p_flag & SVFORK) == 0)
346	vrelvm();
347	else {
348	u.u_procp->p_flag &= ~SVFORK;
349	u.u_procp->p_flag \|= SKEEP;
350	wakeup((caddr_t)u.u_procp);
351	while ((u.u_procp->p_flag & SVFDONE) == 0)
352	sleep((caddr_t)u.u_procp, PZERO - 1);
353	u.u_procp->p_flag &= ~(SVFDONE\|SKEEP);
354	}
355	u.u_procp->p_flag &= ~(SPAGI\|SSEQL\|SUANOM\|SNUSIG);
356	u.u_procp->p_flag \|= pagi;
357	u.u_dmap = u.u_cdmap;
358	u.u_smap = u.u_csmap;
359	vgetvm(ts, ds, ss);
360
361	if (pagi == 0)
362	u.u_error =
363	rdwri(UIO_READ, ip,
364	(char *)ctob(dptov(u.u_procp, 0)),
365	(int)u.u_exdata.ux_dsize,
366	(int)(sizeof(u.u_exdata)+u.u_exdata.ux_tsize),
367	0, (int *)0);
368	xalloc(ip, pagi);
369	if (pagi && u.u_procp->p_textp)
370	vinifod((struct fpte *)dptopte(u.u_procp, 0),
371	PG_FTEXT, u.u_procp->p_textp->x_iptr,
372	(long)(1 + ts/CLSIZE), (int)btoc(u.u_exdata.ux_dsize));
373
374	#ifdef vax
375	/* THIS SHOULD BE DONE AT A LOWER LEVEL, IF AT ALL */
376	#include "../vax/mtpr.h" /* XXX */
377	mtpr(TBIA, 0);
378	#endif
379
380	if (u.u_error)
381	swkill(u.u_procp, "i/o error mapping pages");
382	/*
383	* set SUID/SGID protections, if no tracing
384	*/
385	if ((u.u_procp->p_flag&STRC)==0) {
386	u.u_uid = uid;
387	u.u_procp->p_uid = uid;
388	u.u_gid = gid;
389	} else
390	psignal(u.u_procp, SIGTRAP);
391	u.u_tsize = ts;
392	u.u_dsize = ds;
393	u.u_ssize = ss;
394	bad:
395	return;
396	}
397
398	/*
399	* Clear registers on exec
400	*/
401	setregs()
402	{
403	register int (**rp)();
404	register int i, sigmask;
405
406	for (rp = &u.u_signal[1], sigmask = 1; rp < &u.u_signal[NSIG];
407	sigmask <<= 1, rp++) {
408	switch (*rp) {
409
410	case SIG_IGN:
411	case SIG_DFL:
412	case SIG_HOLD:
413	continue;
414
415	default:
416	/*
417	* Normal or deferring catch; revert to default.
418	*/
419	(void) spl6();
420	*rp = SIG_DFL;
421	if ((int)*rp & 1)
422	u.u_procp->p_siga0 \|= sigmask;
423	else
424	u.u_procp->p_siga0 &= ~sigmask;
425	if ((int)*rp & 2)
426	u.u_procp->p_siga1 \|= sigmask;
427	else
428	u.u_procp->p_siga1 &= ~sigmask;
429	(void) spl0();
430	continue;
431	}
432	}
433	#ifdef vax
434	/*
435	for (rp = &u.u_ar0[0]; rp < &u.u_ar0[16];)
436	*rp++ = 0;
437	*/
438	u.u_ar0[PC] = u.u_exdata.ux_entloc+2;
439	#endif
440	#ifdef sun
441	{ register struct regs r = (struct regs )u.u_ar0;
442	for (i = 0; i < 8; i++) {
443	r->r_dreg[i] = 0;
444	if (&r->r_areg[i] != &r->r_sp)
445	r->r_areg[i] = 0;
446	}
447	r->r_sr = PSL_USERSET;
448	r->r_pc = u.u_exdata.ux_entloc;
449	}
450	#endif
451	for (i=0; i<NOFILE; i++) {
452	if (u.u_pofile[i]&UF_EXCLOSE) {
453	closef(u.u_ofile[i], u.u_pofile[i]);
454	u.u_ofile[i] = NULL;
455	u.u_pofile[i] = 0;
456	}
457	u.u_pofile[i] &= ~UF_MAPPED;
458	}
459
460	/*
461	* Remember file name for accounting.
462	*/
463	u.u_acflag &= ~AFORK;
464	bcopy((caddr_t)u.u_dent.d_name, (caddr_t)u.u_comm,
465	(unsigned)(u.u_dent.d_namlen + 1));
466	#ifdef sun
467	u.u_eosys = REALLYRETURN;
468	#endif
469	}