X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/d7e7a4ec0579987641ab9021cb40c0e5c0c867d2..4e6e38871c68cf8ddfa65c3f6a0d0b2f3a1b2caf:/usr/src/sys/kern/kern_proc.c

diff --git a/usr/src/sys/kern/kern_proc.c b/usr/src/sys/kern/kern_proc.c
index 1c72a95e44..53cab4f7c7 100644
--- a/usr/src/sys/kern/kern_proc.c
+++ b/usr/src/sys/kern/kern_proc.c
@@ -1,4 +1,4 @@
-/*	kern_proc.c	3.14	%G%	*/
+/*	kern_proc.c	4.25	82/04/02	*/
 
 #include "../h/param.h"
 #include "../h/systm.h"
@@ -17,6 +17,8 @@
 #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.
@@ -40,20 +42,124 @@ exece()
 	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)
+	if ((ip = namei(uchar, 0, 1)) == NULL)
 		return;
 	bno = 0;
 	bp = 0;
-	if(access(ip, IEXEC))
+	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((ip->i_mode & IFMT) != IFREG ||
+	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, 1);
+		if (ip == NULL)
+			return;
+		goto again;
+	}
+
 	/*
 	 * Collect arguments on "file" in swap space.
 	 */
@@ -61,15 +167,17 @@ exece()
 	ne = 0;
 	nc = 0;
 	uap = (struct execa *)u.u_ap;
-	if ((bno = malloc(argmap, ctod(clrnd((int) btoc(NCARGS))))) == 0) {
+	if ((bno = rmalloc(argmap, ctod(clrnd((int) btoc(NCARGS))))) == 0) {
 		swkill(u.u_procp, "exece");
 		goto bad;
 	}
 	if (bno % CLSIZE)
-		panic("execa malloc");
+		panic("execa rmalloc");
 	if (uap->argp) for (;;) {
 		ap = NULL;
-		if (uap->argp) {
+		if (indir && (na == 1 || na == 2 && sharg))
+			ap = (int)uap->fname;
+		else if (uap->argp) {
 			ap = fuword((caddr_t)uap->argp);
 			uap->argp++;
 		}
@@ -83,12 +191,14 @@ exece()
 		if (ap==NULL)
 			break;
 		na++;
-		if(ap == -1)
+		if (ap == -1)
 			u.u_error = EFAULT;
 		do {
 			if (nc >= NCARGS-1)
 				u.u_error = E2BIG;
-			if ((c = fubyte((caddr_t)ap++)) < 0)
+			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)
@@ -111,7 +221,10 @@ exece()
 		bdwrite(bp);
 	bp = 0;
 	nc = (nc + NBPW-1) & ~(NBPW-1);
-	if (getxfile(ip, nc) || u.u_error) {
+	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))) {
@@ -126,7 +239,6 @@ badarg:
 	/*
 	 * copy back arglist
 	 */
-
 	ucp = USRSTACK - nc - NBPW;
 	ap = ucp - na*NBPW - 3*NBPW;
 	u.u_ar0[SP] = ap;
@@ -162,181 +274,112 @@ bad:
 	if (bp)
 		brelse(bp);
 	if (bno)
-		mfree(argmap, ctod(clrnd((int) btoc(NCARGS))), bno);
+		rmfree(argmap, ctod(clrnd((int) btoc(NCARGS))), bno);
 	iput(ip);
 }
 
 /*
  * Read in and set up memory for executed file.
- * Zero return is normal;
- * non-zero means only the text is being replaced
  */
-getxfile(ip, nargc)
+getxfile(ip, nargc, uid, gid)
 register struct inode *ip;
 {
-	register sep;
 	register size_t ts, ds, ss;
-	register int overlay;
-	int pagi = 0;
-
-	/*
-	 * read in first few bytes
-	 * of file for segment
-	 * sizes:
-	 * ux_mag = 407/410/411/405
-	 *  407 is plain executable
-	 *  410 is RO text
-	 *  411 is separated ID
-	 *  405 is overlaid text
-	 *  412 is demand paged plain executable (NOT IMPLEMENTED)
-	 *  413 is demand paged RO text
-	 */
-
-	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!=0) {
-		u.u_error = ENOEXEC;
-		goto bad;
-	}
-	sep = 0;
-	overlay = 0;
-	switch (u.u_exdata.ux_mag) {
-
-	case 0405:
-		overlay++;
-		break;
+	int pagi;
 
-	case 0412:
-		u.u_error = ENOEXEC;
-		goto bad;
-
-	case 0407:
-		u.u_exdata.ux_dsize += u.u_exdata.ux_tsize;
-		u.u_exdata.ux_tsize = 0;
-		break;
-
-	case 0413:
+	if (u.u_exdata.ux_mag == 0413)
 		pagi = SPAGI;
-		/* fall into ... */
-
-	case 0410:
-		if (u.u_exdata.ux_tsize == 0) {
-			u.u_error = ENOEXEC;
-			goto bad;
+	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_flag & FSOCKET)
+				continue;
+			if (fp->f_inode == ip && (fp->f_flag&FWRITE)) {
+				u.u_error = ETXTBSY;
+				goto bad;
+			}
 		}
-		break;
-
-	case 0411:
-		u.u_error = ENOEXEC;
-		goto bad;
-
-	default:
-		u.u_error = ENOEXEC;
-		goto bad;
-	}
-	if(u.u_exdata.ux_tsize!=0 && (ip->i_flag&ITEXT)==0 && ip->i_count!=1) {
-		u.u_error = ETXTBSY;
-		goto bad;
 	}
 
 	/*
-	 * find text and data sizes
-	 * try them out for possible
-	 * exceed of max sizes
+	 * 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 (overlay) {
-		if ((u.u_procp->p_flag & SPAGI) ||
-		    u.u_sep==0 && ctos(ts) != ctos(u.u_tsize) || nargc) {
-			u.u_error = ENOMEM;
-			goto bad;
-		}
-		ds = u.u_dsize;
-		ss = u.u_ssize;
-		sep = u.u_sep;
-		xfree();
-		xalloc(ip, pagi);
-		u.u_ar0[PC] = u.u_exdata.ux_entloc + 2; /* skip over entry mask */
-	} else {
-		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|SANOM|SUANOM);
-		u.u_procp->p_flag |= pagi;
-		u.u_dmap = u.u_cdmap;
-		u.u_smap = u.u_csmap;
-		vgetvm(ts, ds, ss);
+	if (chksize(ts, ds, ss))
+		goto bad;
 
-		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));
+	/*
+	 * 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;
 
-		/* THIS SHOULD BE DONE AT A LOWER LEVEL, IF AT ALL */
-		mtpr(TBIA, 0);
+	/*
+	 * 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) {
 		/*
-		 * set SUID/SGID protections, if no tracing
+		 * Read in data segment.
 		 */
-		if ((u.u_procp->p_flag&STRC)==0) {
-			if(ip->i_mode&ISUID)
-				if(u.u_uid != 0) {
-					u.u_uid = ip->i_uid;
-					u.u_procp->p_uid = ip->i_uid;
-				}
-			if(ip->i_mode&ISGID)
-				u.u_gid = ip->i_gid;
-		} else
-			psignal(u.u_procp, SIGTRAP);
+		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) {
+		u.u_uid = uid;
+		u.u_procp->p_uid = uid;
+		u.u_gid = gid;
+		u.u_grps[gid/(sizeof(int)*8)] |= 1 << (gid%(sizeof(int)*8));
+	} else
+		psignal(u.u_procp, SIGTRAP);
 	u.u_tsize = ts;
 	u.u_dsize = ds;
 	u.u_ssize = ss;
-	u.u_sep = sep;
 bad:
-	return(overlay);
+	return;
 }
 
 /*
@@ -348,7 +391,7 @@ setregs()
 	register i;
 	long sigmask;
 
-	for(rp = &u.u_signal[0], sigmask = 1L; rp < &u.u_signal[NSIG];
+	for (rp = &u.u_signal[1], sigmask = 1L; rp < &u.u_signal[NSIG];
 	    sigmask <<= 1, rp++) {
 		switch (*rp) {
 
@@ -366,7 +409,7 @@ setregs()
 			if ((int)*rp & 1)
 				u.u_procp->p_siga0 |= sigmask;
 			else
-				u.u_procp->p_siga1 &= ~sigmask;
+				u.u_procp->p_siga0 &= ~sigmask;
 			if ((int)*rp & 2)
 				u.u_procp->p_siga1 |= sigmask;
 			else
@@ -376,17 +419,18 @@ setregs()
 		}
 	}
 /*
-	for(rp = &u.u_ar0[0]; rp < &u.u_ar0[16];)
+	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++) {
+	for (i=0; i<NOFILE; i++) {
 		if (u.u_pofile[i]&EXCLOSE) {
-			closef(u.u_ofile[i]);
+			closef(u.u_ofile[i], 1);
 			u.u_ofile[i] = NULL;
 			u.u_pofile[i] &= ~EXCLOSE;
 		}
 	}
+
 	/*
 	 * Remember file name for accounting.
 	 */
@@ -395,8 +439,7 @@ setregs()
 }
 
 /*
- * exit system call:
- * pass back caller's arg
+ * Exit system call: pass back caller's arg
  */
 rexit()
 {
@@ -439,8 +482,9 @@ exit(rv)
 	else
 		p->p_siga1 = 0;
 	(void) spl0();
-	p->p_aveflt = 0;
-	for(i=0; i<NSIG; i++)
+	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
@@ -456,24 +500,25 @@ exit(rv)
 			sleep((caddr_t)p, PZERO - 1);
 		p->p_flag &= ~SVFDONE;
 	}
-	for(i=0; i<NOFILE; i++) {
+	for (i=0; i<NOFILE; i++) {
 		f = u.u_ofile[i];
 		u.u_ofile[i] = NULL;
-		closef(f);
+		closef(f, 1);
 	}
-	plock(u.u_cdir);
+	ilock(u.u_cdir);
 	iput(u.u_cdir);
 	if (u.u_rdir) {
-		plock(u.u_rdir);
+		ilock(u.u_rdir);
 		iput(u.u_rdir);
 	}
+	u.u_limit[LIM_FSIZE] = INFINITY;
 	acct();
 	vrelpt(u.u_procp);
 	vrelu(u.u_procp, 0);
+	(void) spl5();		/* hack for mem alloc race XXX */
 	multprog--;
-/*	spl7();			/* clock will get mad because of overlaying */
-	noproc = 1;
 	p->p_stat = SZOMB;
+	noproc = 1;
 	i = PIDHASH(p->p_pid);
 	x = p - proc;
 	if (pidhash[i] == x)
@@ -486,20 +531,21 @@ exit(rv)
 			}
 		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[0]; q < &proc[NPROC]; q++)
-		if(q->p_pptr == p) {
+	for (q = proc; q < procNPROC; q++)
+		if (q->p_pptr == p) {
 			q->p_pptr = &proc[1];
 			q->p_ppid = 1;
-			q->p_flag |= SDETACH;
 			wakeup((caddr_t)&proc[1]);
 			/*
 			 * Traced processes are killed
 			 * since their existence means someone is screwing up.
-			 * Traced processes are sent a hangup and a continue.
+			 * 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.
@@ -513,12 +559,12 @@ done:
 			}
 			/*
 			 * Protect this process from future
-			 * tty signals, and clear TSTP/TTIN/TTOU if pending.
+			 * tty signals, clear TSTP/TTIN/TTOU if pending.
 			 */
-			spgrp(q, -1);
+			(void) spgrp(q, -1);
 		}
-	wakeup((caddr_t)p->p_pptr);
 	psignal(p->p_pptr, SIGCHLD);
+	wakeup((caddr_t)p->p_pptr);
 	swtch();
 }
 
@@ -554,10 +600,10 @@ wait1(options, vp)
 
 	f = 0;
 loop:
-	for(p = &proc[0]; p < &proc[NPROC]; p++)
-	if(p->p_pptr == u.u_procp) {
+	for (p = proc; p < procNPROC; p++)
+	if (p->p_pptr == u.u_procp) {
 		f++;
-		if(p->p_stat == SZOMB) {
+		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;
@@ -594,12 +640,10 @@ loop:
 		u.u_r.r_val1 = 0;
 		return;
 	}
-/*
-	if (setjmp(u.u_qsav)) {
+	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;
 }
@@ -626,7 +670,7 @@ fork1(isvfork)
 
 	a = 0;
 	p2 = NULL;
-	for(p1 = &proc[0]; p1 < &proc[NPROC]; p1++) {
+	for (p1 = proc; p1 < procNPROC; p1++) {
 		if (p1->p_stat==NULL && p2==NULL)
 			p2 = p1;
 		else {
@@ -640,7 +684,9 @@ fork1(isvfork)
 	 *  not su and too many procs owned; or
 	 *  not su and would take last slot.
 	 */
-	if (p2==NULL || (u.u_uid!=0 && (p2==&proc[NPROC-1] || a>MAXUPRC))) {
+	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);
@@ -649,7 +695,7 @@ fork1(isvfork)
 		goto out;
 	}
 	p1 = u.u_procp;
-	if(newproc(isvfork)) {
+	if (newproc(isvfork)) {
 		u.u_r.r_val1 = p1->p_pid;
 		u.u_r.r_val2 = 1;  /* child */
 		u.u_start = time;
@@ -684,6 +730,10 @@ sbreak()
 	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)