| 1 | /* kern_proc.c 3.4 %H% */ |
| 2 | |
| 3 | #include "../h/param.h" |
| 4 | #include "../h/systm.h" |
| 5 | #include "../h/map.h" |
| 6 | #include "../h/mtpr.h" |
| 7 | #include "../h/dir.h" |
| 8 | #include "../h/user.h" |
| 9 | #include "../h/proc.h" |
| 10 | #include "../h/buf.h" |
| 11 | #include "../h/reg.h" |
| 12 | #include "../h/inode.h" |
| 13 | #include "../h/seg.h" |
| 14 | #include "../h/acct.h" |
| 15 | #include "../h/pte.h" |
| 16 | #include "../h/vm.h" |
| 17 | #include "../h/text.h" |
| 18 | |
| 19 | /* |
| 20 | * exec system call, with and without environments. |
| 21 | */ |
| 22 | struct execa { |
| 23 | char *fname; |
| 24 | char **argp; |
| 25 | char **envp; |
| 26 | }; |
| 27 | |
| 28 | exec() |
| 29 | { |
| 30 | ((struct execa *)u.u_ap)->envp = NULL; |
| 31 | exece(); |
| 32 | } |
| 33 | |
| 34 | exece() |
| 35 | { |
| 36 | register nc; |
| 37 | register char *cp; |
| 38 | register struct buf *bp; |
| 39 | register struct execa *uap; |
| 40 | int na, ne, ucp, ap, c; |
| 41 | struct inode *ip; |
| 42 | swblk_t bno; |
| 43 | |
| 44 | if ((ip = namei(uchar, 0)) == NULL) |
| 45 | return; |
| 46 | bno = 0; |
| 47 | bp = 0; |
| 48 | if(access(ip, IEXEC)) |
| 49 | goto bad; |
| 50 | if((ip->i_mode & IFMT) != IFREG || |
| 51 | (ip->i_mode & (IEXEC|(IEXEC>>3)|(IEXEC>>6))) == 0) { |
| 52 | u.u_error = EACCES; |
| 53 | goto bad; |
| 54 | } |
| 55 | /* |
| 56 | * Collect arguments on "file" in swap space. |
| 57 | */ |
| 58 | na = 0; |
| 59 | ne = 0; |
| 60 | nc = 0; |
| 61 | uap = (struct execa *)u.u_ap; |
| 62 | if ((bno = malloc(swapmap, ctod(clrnd((int) btoc(NCARGS))))) == 0) { |
| 63 | swkill(u.u_procp, "exece"); |
| 64 | goto bad; |
| 65 | } |
| 66 | if (bno % CLSIZE) |
| 67 | panic("execa malloc"); |
| 68 | if (uap->argp) for (;;) { |
| 69 | ap = NULL; |
| 70 | if (uap->argp) { |
| 71 | ap = fuword((caddr_t)uap->argp); |
| 72 | uap->argp++; |
| 73 | } |
| 74 | if (ap==NULL && uap->envp) { |
| 75 | uap->argp = NULL; |
| 76 | if ((ap = fuword((caddr_t)uap->envp)) == NULL) |
| 77 | break; |
| 78 | uap->envp++; |
| 79 | ne++; |
| 80 | } |
| 81 | if (ap==NULL) |
| 82 | break; |
| 83 | na++; |
| 84 | if(ap == -1) |
| 85 | u.u_error = EFAULT; |
| 86 | do { |
| 87 | if (nc >= NCARGS-1) |
| 88 | u.u_error = E2BIG; |
| 89 | if ((c = fubyte((caddr_t)ap++)) < 0) |
| 90 | u.u_error = EFAULT; |
| 91 | if (u.u_error) { |
| 92 | if (bp) |
| 93 | brelse(bp); |
| 94 | bp = 0; |
| 95 | goto badarg; |
| 96 | } |
| 97 | if ((nc&BMASK) == 0) { |
| 98 | if (bp) |
| 99 | bdwrite(bp); |
| 100 | bp = getblk(swapdev, (daddr_t)(dbtofsb(swplo+bno)+(nc>>BSHIFT))); |
| 101 | cp = bp->b_un.b_addr; |
| 102 | } |
| 103 | nc++; |
| 104 | *cp++ = c; |
| 105 | } while (c>0); |
| 106 | } |
| 107 | if (bp) |
| 108 | bdwrite(bp); |
| 109 | bp = 0; |
| 110 | nc = (nc + NBPW-1) & ~(NBPW-1); |
| 111 | if (getxfile(ip, nc) || u.u_error) { |
| 112 | badarg: |
| 113 | for (c = 0; c < nc; c += BSIZE) |
| 114 | if (bp = baddr(swapdev, dbtofsb(swplo+bno)+(c>>BSHIFT))) { |
| 115 | bp->b_flags |= B_AGE; /* throw away */ |
| 116 | bp->b_flags &= ~B_DELWRI; /* cancel io */ |
| 117 | brelse(bp); |
| 118 | bp = 0; |
| 119 | } |
| 120 | goto bad; |
| 121 | } |
| 122 | |
| 123 | /* |
| 124 | * copy back arglist |
| 125 | */ |
| 126 | |
| 127 | ucp = USRSTACK - nc - NBPW; |
| 128 | ap = ucp - na*NBPW - 3*NBPW; |
| 129 | u.u_ar0[SP] = ap; |
| 130 | (void) suword((caddr_t)ap, na-ne); |
| 131 | nc = 0; |
| 132 | for (;;) { |
| 133 | ap += NBPW; |
| 134 | if (na==ne) { |
| 135 | (void) suword((caddr_t)ap, 0); |
| 136 | ap += NBPW; |
| 137 | } |
| 138 | if (--na < 0) |
| 139 | break; |
| 140 | (void) suword((caddr_t)ap, ucp); |
| 141 | do { |
| 142 | if ((nc&BMASK) == 0) { |
| 143 | if (bp) |
| 144 | brelse(bp); |
| 145 | bp = bread(swapdev, (daddr_t)(dbtofsb(swplo+bno)+(nc>>BSHIFT))); |
| 146 | bp->b_flags |= B_AGE; /* throw away */ |
| 147 | bp->b_flags &= ~B_DELWRI; /* cancel io */ |
| 148 | cp = bp->b_un.b_addr; |
| 149 | } |
| 150 | (void) subyte((caddr_t)ucp++, (c = *cp++)); |
| 151 | nc++; |
| 152 | } while(c&0377); |
| 153 | } |
| 154 | (void) suword((caddr_t)ap, 0); |
| 155 | (void) suword((caddr_t)ucp, 0); |
| 156 | setregs(); |
| 157 | bad: |
| 158 | if (bp) |
| 159 | brelse(bp); |
| 160 | if (bno) |
| 161 | mfree(swapmap, ctod(clrnd((int) btoc(NCARGS))), bno); |
| 162 | iput(ip); |
| 163 | } |
| 164 | |
| 165 | /* |
| 166 | * Read in and set up memory for executed file. |
| 167 | * Zero return is normal; |
| 168 | * non-zero means only the text is being replaced |
| 169 | */ |
| 170 | getxfile(ip, nargc) |
| 171 | register struct inode *ip; |
| 172 | { |
| 173 | register sep; |
| 174 | register size_t ts, ds, ss; |
| 175 | register int overlay; |
| 176 | int pagi = 0; |
| 177 | |
| 178 | /* |
| 179 | * read in first few bytes |
| 180 | * of file for segment |
| 181 | * sizes: |
| 182 | * ux_mag = 407/410/411/405 |
| 183 | * 407 is plain executable |
| 184 | * 410 is RO text |
| 185 | * 411 is separated ID |
| 186 | * 405 is overlaid text |
| 187 | * 412 is demand paged plain executable (NOT IMPLEMENTED) |
| 188 | * 413 is demand paged RO text |
| 189 | */ |
| 190 | |
| 191 | u.u_base = (caddr_t)&u.u_exdata; |
| 192 | u.u_count = sizeof(u.u_exdata); |
| 193 | u.u_offset = 0; |
| 194 | u.u_segflg = 1; |
| 195 | readi(ip); |
| 196 | u.u_segflg = 0; |
| 197 | if(u.u_error) |
| 198 | goto bad; |
| 199 | if (u.u_count!=0) { |
| 200 | u.u_error = ENOEXEC; |
| 201 | goto bad; |
| 202 | } |
| 203 | sep = 0; |
| 204 | overlay = 0; |
| 205 | switch (u.u_exdata.ux_mag) { |
| 206 | |
| 207 | case 0405: |
| 208 | overlay++; |
| 209 | break; |
| 210 | |
| 211 | case 0412: |
| 212 | u.u_error = ENOEXEC; |
| 213 | goto bad; |
| 214 | |
| 215 | case 0407: |
| 216 | u.u_exdata.ux_dsize += u.u_exdata.ux_tsize; |
| 217 | u.u_exdata.ux_tsize = 0; |
| 218 | break; |
| 219 | |
| 220 | case 0413: |
| 221 | pagi = SPAGI; |
| 222 | /* fall into ... */ |
| 223 | |
| 224 | case 0410: |
| 225 | if (u.u_exdata.ux_tsize == 0) { |
| 226 | u.u_error = ENOEXEC; |
| 227 | goto bad; |
| 228 | } |
| 229 | break; |
| 230 | |
| 231 | case 0411: |
| 232 | u.u_error = ENOEXEC; |
| 233 | goto bad; |
| 234 | |
| 235 | default: |
| 236 | u.u_error = ENOEXEC; |
| 237 | goto bad; |
| 238 | } |
| 239 | if(u.u_exdata.ux_tsize!=0 && (ip->i_flag&ITEXT)==0 && ip->i_count!=1) { |
| 240 | u.u_error = ETXTBSY; |
| 241 | goto bad; |
| 242 | } |
| 243 | |
| 244 | /* |
| 245 | * find text and data sizes |
| 246 | * try them out for possible |
| 247 | * exceed of max sizes |
| 248 | */ |
| 249 | |
| 250 | ts = clrnd(btoc(u.u_exdata.ux_tsize)); |
| 251 | ds = clrnd(btoc((u.u_exdata.ux_dsize+u.u_exdata.ux_bsize))); |
| 252 | ss = clrnd(SSIZE + btoc(nargc)); |
| 253 | if (overlay) { |
| 254 | if ((u.u_procp->p_flag & SPAGI) || u.u_sep==0 && ctos(ts) != ctos(u.u_tsize) || nargc) { |
| 255 | u.u_error = ENOMEM; |
| 256 | goto bad; |
| 257 | } |
| 258 | ds = u.u_dsize; |
| 259 | ss = u.u_ssize; |
| 260 | sep = u.u_sep; |
| 261 | xfree(); |
| 262 | xalloc(ip, pagi); |
| 263 | u.u_ar0[PC] = u.u_exdata.ux_entloc + 2; /* skip over entry mask */ |
| 264 | } else { |
| 265 | if (chksize(ts, ds, ss)) |
| 266 | goto bad; |
| 267 | u.u_cdmap = zdmap; |
| 268 | u.u_csmap = zdmap; |
| 269 | if (swpexpand(ds, ss, &u.u_cdmap, &u.u_csmap) == NULL) |
| 270 | goto bad; |
| 271 | |
| 272 | /* |
| 273 | * At this point, committed to the new image! |
| 274 | * Release virtual memory resources of old process, and |
| 275 | * initialize the virtual memory of the new process. |
| 276 | * If we resulted from vfork(), instead wakeup our |
| 277 | * parent who will set SVFDONE when he has taken back |
| 278 | * our resources. |
| 279 | */ |
| 280 | u.u_prof.pr_scale = 0; |
| 281 | if ((u.u_procp->p_flag & SVFORK) == 0) |
| 282 | vrelvm(); |
| 283 | else { |
| 284 | u.u_procp->p_flag &= ~SVFORK; |
| 285 | u.u_procp->p_flag |= SKEEP; |
| 286 | wakeup((caddr_t)u.u_procp); |
| 287 | while ((u.u_procp->p_flag & SVFDONE) == 0) |
| 288 | sleep((caddr_t)u.u_procp, PZERO - 1); |
| 289 | u.u_procp->p_flag &= ~(SVFDONE|SKEEP); |
| 290 | } |
| 291 | u.u_procp->p_flag &= ~(SPAGI|SANOM|SUANOM); |
| 292 | u.u_procp->p_flag |= pagi; |
| 293 | u.u_dmap = u.u_cdmap; |
| 294 | u.u_smap = u.u_csmap; |
| 295 | vgetvm(ts, ds, ss); |
| 296 | |
| 297 | if (pagi == 0) { |
| 298 | /* |
| 299 | * Read in data segment. |
| 300 | */ |
| 301 | u.u_base = (char *)ctob(ts); |
| 302 | u.u_offset = sizeof(u.u_exdata)+u.u_exdata.ux_tsize; |
| 303 | u.u_count = u.u_exdata.ux_dsize; |
| 304 | readi(ip); |
| 305 | } |
| 306 | xalloc(ip, pagi); |
| 307 | if (pagi && u.u_procp->p_textp) |
| 308 | vinifod((struct fpte *)dptopte(u.u_procp, 0), |
| 309 | PG_FTEXT, u.u_procp->p_textp->x_iptr, |
| 310 | 1 + ts/CLSIZE, (int)btoc(u.u_exdata.ux_dsize)); |
| 311 | |
| 312 | /* THIS SHOULD BE DONE AT A LOWER LEVEL, IF AT ALL */ |
| 313 | mtpr(TBIA,1); |
| 314 | |
| 315 | /* |
| 316 | * set SUID/SGID protections, if no tracing |
| 317 | */ |
| 318 | if ((u.u_procp->p_flag&STRC)==0) { |
| 319 | if(ip->i_mode&ISUID) |
| 320 | if(u.u_uid != 0) { |
| 321 | u.u_uid = ip->i_uid; |
| 322 | u.u_procp->p_uid = ip->i_uid; |
| 323 | } |
| 324 | if(ip->i_mode&ISGID) |
| 325 | u.u_gid = ip->i_gid; |
| 326 | } else |
| 327 | psignal(u.u_procp, SIGTRAP); |
| 328 | } |
| 329 | u.u_tsize = ts; |
| 330 | u.u_dsize = ds; |
| 331 | u.u_ssize = ss; |
| 332 | u.u_sep = sep; |
| 333 | bad: |
| 334 | return(overlay); |
| 335 | } |
| 336 | |
| 337 | /* |
| 338 | * Clear registers on exec |
| 339 | */ |
| 340 | setregs() |
| 341 | { |
| 342 | register int (**rp)(); |
| 343 | register i; |
| 344 | |
| 345 | for(rp = &u.u_signal[0]; rp < &u.u_signal[NSIG]; rp++) |
| 346 | if(((int)*rp & 1) == 0) |
| 347 | *rp = 0; |
| 348 | /* |
| 349 | for(rp = &u.u_ar0[0]; rp < &u.u_ar0[16];) |
| 350 | *rp++ = 0; |
| 351 | */ |
| 352 | u.u_ar0[PC] = u.u_exdata.ux_entloc + 2; /* skip over entry mask */ |
| 353 | for(i=0; i<NOFILE; i++) { |
| 354 | if (u.u_pofile[i]&EXCLOSE) { |
| 355 | closef(u.u_ofile[i]); |
| 356 | u.u_ofile[i] = NULL; |
| 357 | } |
| 358 | u.u_pofile[i] &= ~EXCLOSE; |
| 359 | } |
| 360 | /* |
| 361 | * Remember file name for accounting. |
| 362 | */ |
| 363 | u.u_acflag &= ~AFORK; |
| 364 | bcopy((caddr_t)u.u_dbuf, (caddr_t)u.u_comm, DIRSIZ); |
| 365 | } |
| 366 | |
| 367 | /* |
| 368 | * exit system call: |
| 369 | * pass back caller's arg |
| 370 | */ |
| 371 | rexit() |
| 372 | { |
| 373 | register struct a { |
| 374 | int rval; |
| 375 | } *uap; |
| 376 | |
| 377 | uap = (struct a *)u.u_ap; |
| 378 | exit((uap->rval & 0377) << 8); |
| 379 | } |
| 380 | |
| 381 | /* |
| 382 | * Release resources. |
| 383 | * Save u. area for parent to look at. |
| 384 | * Enter zombie state. |
| 385 | * Wake up parent and init processes, |
| 386 | * and dispose of children. |
| 387 | */ |
| 388 | exit(rv) |
| 389 | { |
| 390 | register int i; |
| 391 | register struct proc *p, *q; |
| 392 | register struct file *f; |
| 393 | register int x; |
| 394 | |
| 395 | #ifdef PGINPROF |
| 396 | vmsizmon(); |
| 397 | #endif |
| 398 | p = u.u_procp; |
| 399 | p->p_flag &= ~(STRC|SULOCK); |
| 400 | p->p_flag |= SWEXIT; |
| 401 | p->p_clktim = 0; |
| 402 | rate.v_pgin -= p->p_aveflt; |
| 403 | p->p_aveflt = 0; |
| 404 | for(i=0; i<NSIG; i++) |
| 405 | u.u_signal[i] = SIG_IGN; |
| 406 | /* |
| 407 | * Release virtual memory. If we resulted from |
| 408 | * a vfork(), instead give the resources back to |
| 409 | * the parent. |
| 410 | */ |
| 411 | if ((p->p_flag & SVFORK) == 0) |
| 412 | vrelvm(); |
| 413 | else { |
| 414 | p->p_flag &= ~SVFORK; |
| 415 | wakeup((caddr_t)p); |
| 416 | while ((p->p_flag & SVFDONE) == 0) |
| 417 | sleep((caddr_t)p, PZERO - 1); |
| 418 | p->p_flag &= ~SVFDONE; |
| 419 | } |
| 420 | for(i=0; i<NOFILE; i++) { |
| 421 | f = u.u_ofile[i]; |
| 422 | u.u_ofile[i] = NULL; |
| 423 | closef(f); |
| 424 | } |
| 425 | plock(u.u_cdir); |
| 426 | iput(u.u_cdir); |
| 427 | if (u.u_rdir) { |
| 428 | plock(u.u_rdir); |
| 429 | iput(u.u_rdir); |
| 430 | } |
| 431 | acct(); |
| 432 | vrelpt(u.u_procp); |
| 433 | vrelu(u.u_procp, 0); |
| 434 | multprog--; |
| 435 | spl7(); /* clock will get mad because of overlaying */ |
| 436 | p->p_stat = SZOMB; |
| 437 | i = PIDHASH(p->p_pid); |
| 438 | x = p - proc; |
| 439 | if (pidhash[i] == x) |
| 440 | pidhash[i] = p->p_idhash; |
| 441 | else { |
| 442 | for (i = pidhash[i]; i != 0; i = proc[i].p_idhash) |
| 443 | if (proc[i].p_idhash == x) { |
| 444 | proc[i].p_idhash = p->p_idhash; |
| 445 | goto done; |
| 446 | } |
| 447 | panic("exit"); |
| 448 | } |
| 449 | done: |
| 450 | ((struct xproc *)p)->xp_xstat = rv; /* overlay */ |
| 451 | ((struct xproc *)p)->xp_vm = u.u_vm; /* overlay */ |
| 452 | vmsadd(&((struct xproc *)p)->xp_vm, &u.u_cvm); |
| 453 | for(q = &proc[0]; q < &proc[NPROC]; q++) |
| 454 | if(q->p_ppid == p->p_pid) { |
| 455 | wakeup((caddr_t)&proc[1]); |
| 456 | q->p_ppid = 1; |
| 457 | if (q->p_stat==SSTOP) |
| 458 | setrun(q); |
| 459 | } |
| 460 | q = pfind(p->p_ppid); |
| 461 | if (q) |
| 462 | wakeup((caddr_t)q); |
| 463 | swtch(); |
| 464 | } |
| 465 | |
| 466 | wait() |
| 467 | { |
| 468 | |
| 469 | wait1((struct vtimes *)0); |
| 470 | } |
| 471 | |
| 472 | /* |
| 473 | * Wait system call. |
| 474 | * Search for a terminated (zombie) child, |
| 475 | * finally lay it to rest, and collect its status. |
| 476 | * Look also for stopped (traced) children, |
| 477 | * and pass back status from them. |
| 478 | */ |
| 479 | wait1(vp) |
| 480 | struct vtimes *vp; |
| 481 | { |
| 482 | register f; |
| 483 | register struct proc *p; |
| 484 | |
| 485 | f = 0; |
| 486 | |
| 487 | loop: |
| 488 | for(p = &proc[0]; p < &proc[NPROC]; p++) |
| 489 | if(p->p_ppid == u.u_procp->p_pid) { |
| 490 | f++; |
| 491 | if(p->p_stat == SZOMB) { |
| 492 | u.u_r.r_val1 = p->p_pid; |
| 493 | u.u_r.r_val2 = ((struct xproc *)p)->xp_xstat; |
| 494 | ((struct xproc *)p)->xp_xstat = 0; |
| 495 | if (vp) |
| 496 | *vp = ((struct xproc *)p)->xp_vm; |
| 497 | vmsadd(&u.u_cvm, &((struct xproc *)p)->xp_vm); |
| 498 | ((struct xproc *)p)->xp_vm = zvms; |
| 499 | p->p_stat = NULL; |
| 500 | p->p_pid = 0; |
| 501 | p->p_ppid = 0; |
| 502 | p->p_sig = 0; |
| 503 | p->p_pgrp = 0; |
| 504 | p->p_flag = 0; |
| 505 | p->p_wchan = 0; |
| 506 | return; |
| 507 | } |
| 508 | if(p->p_stat == SSTOP) { |
| 509 | if((p->p_flag&SWTED) == 0) { |
| 510 | p->p_flag |= SWTED; |
| 511 | u.u_r.r_val1 = p->p_pid; |
| 512 | u.u_r.r_val2 = (fsig(p)<<8) | 0177; |
| 513 | return; |
| 514 | } |
| 515 | continue; |
| 516 | } |
| 517 | } |
| 518 | if(f) { |
| 519 | sleep((caddr_t)u.u_procp, PWAIT); |
| 520 | goto loop; |
| 521 | } |
| 522 | u.u_error = ECHILD; |
| 523 | } |
| 524 | |
| 525 | /* |
| 526 | * fork system call. |
| 527 | */ |
| 528 | fork() |
| 529 | { |
| 530 | |
| 531 | u.u_cdmap = zdmap; |
| 532 | u.u_csmap = zdmap; |
| 533 | if (swpexpand(u.u_dsize, u.u_ssize, &u.u_cdmap, &u.u_csmap) == 0) { |
| 534 | u.u_r.r_val2 = 0; |
| 535 | return; |
| 536 | } |
| 537 | fork1(0); |
| 538 | } |
| 539 | |
| 540 | fork1(isvfork) |
| 541 | { |
| 542 | register struct proc *p1, *p2; |
| 543 | register a; |
| 544 | |
| 545 | a = 0; |
| 546 | p2 = NULL; |
| 547 | for(p1 = &proc[0]; p1 < &proc[NPROC]; p1++) { |
| 548 | if (p1->p_stat==NULL && p2==NULL) |
| 549 | p2 = p1; |
| 550 | else { |
| 551 | if (p1->p_uid==u.u_uid && p1->p_stat!=NULL) |
| 552 | a++; |
| 553 | } |
| 554 | } |
| 555 | /* |
| 556 | * Disallow if |
| 557 | * No processes at all; |
| 558 | * not su and too many procs owned; or |
| 559 | * not su and would take last slot. |
| 560 | */ |
| 561 | if (p2==NULL || (u.u_uid!=0 && (p2==&proc[NPROC-1] || a>MAXUPRC))) { |
| 562 | u.u_error = EAGAIN; |
| 563 | if (!isvfork) { |
| 564 | (void) vsexpand(0, &u.u_cdmap, 1); |
| 565 | (void) vsexpand(0, &u.u_csmap, 1); |
| 566 | } |
| 567 | goto out; |
| 568 | } |
| 569 | p1 = u.u_procp; |
| 570 | if(newproc(isvfork)) { |
| 571 | u.u_r.r_val1 = p1->p_pid; |
| 572 | u.u_r.r_val2 = 1; /* child */ |
| 573 | u.u_start = time; |
| 574 | u.u_acflag = AFORK; |
| 575 | return; |
| 576 | } |
| 577 | u.u_r.r_val1 = p2->p_pid; |
| 578 | |
| 579 | out: |
| 580 | u.u_r.r_val2 = 0; |
| 581 | } |
| 582 | |
| 583 | /* |
| 584 | * break system call. |
| 585 | * -- bad planning: "break" is a dirty word in C. |
| 586 | */ |
| 587 | sbreak() |
| 588 | { |
| 589 | struct a { |
| 590 | char *nsiz; |
| 591 | }; |
| 592 | register int n, d; |
| 593 | |
| 594 | /* |
| 595 | * set n to new data size |
| 596 | * set d to new-old |
| 597 | */ |
| 598 | |
| 599 | n = btoc(((struct a *)u.u_ap)->nsiz); |
| 600 | if (!u.u_sep) |
| 601 | n -= ctos(u.u_tsize) * stoc(1); |
| 602 | if (n < 0) |
| 603 | n = 0; |
| 604 | d = clrnd(n - u.u_dsize); |
| 605 | if (chksize(u.u_tsize, u.u_dsize+d, u.u_ssize)) |
| 606 | return; |
| 607 | if (swpexpand(u.u_dsize+d, u.u_ssize, &u.u_dmap, &u.u_smap)==0) |
| 608 | return; |
| 609 | expand(d, P0BR); |
| 610 | } |