1 /* $NetBSD: uvm_glue.c,v 1.93 2006/03/15 18:09:25 drochner Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Charles D. Cranor and Washington University. 5 * Copyright (c) 1991, 1993, The Regents of the University of California. 6 * 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * The Mach Operating System project at Carnegie-Mellon University. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by Charles D. Cranor, 23 * Washington University, the University of California, Berkeley and 24 * its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)vm_glue.c 8.6 (Berkeley) 1/5/94 42 * from: Id: uvm_glue.c,v 1.1.2.8 1998/02/07 01:16:54 chs Exp 43 * 44 * 45 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 46 * All rights reserved. 47 * 48 * Permission to use, copy, modify and distribute this software and 49 * its documentation is hereby granted, provided that both the copyright 50 * notice and this permission notice appear in all copies of the 51 * software, derivative works or modified versions, and any portions 52 * thereof, and that both notices appear in supporting documentation. 53 * 54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 57 * 58 * Carnegie Mellon requests users of this software to return to 59 * 60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 61 * School of Computer Science 62 * Carnegie Mellon University 63 * Pittsburgh PA 15213-3890 64 * 65 * any improvements or extensions that they make and grant Carnegie the 66 * rights to redistribute these changes. 67 */ 68 69 #include <sys/cdefs.h> 70 __KERNEL_RCSID(0, "$NetBSD: uvm_glue.c,v 1.93 2006/03/15 18:09:25 drochner Exp $"); 71 72 #include "opt_kgdb.h" 73 #include "opt_kstack.h" 74 #include "opt_uvmhist.h" 75 76 /* 77 * uvm_glue.c: glue functions 78 */ 79 80 #include <sys/param.h> 81 #include <sys/systm.h> 82 #include <sys/proc.h> 83 #include <sys/resourcevar.h> 84 #include <sys/buf.h> 85 #include <sys/user.h> 86 87 #include <uvm/uvm.h> 88 89 #include <machine/cpu.h> 90 91 /* 92 * local prototypes 93 */ 94 95 static void uvm_swapout(struct lwp *); 96 97 #define UVM_NUAREA_MAX 16 98 void *uvm_uareas; 99 int uvm_nuarea; 100 struct simplelock uvm_uareas_slock = SIMPLELOCK_INITIALIZER; 101 102 static void uvm_uarea_free(vaddr_t); 103 104 /* 105 * XXXCDC: do these really belong here? 106 */ 107 108 /* 109 * uvm_kernacc: can the kernel access a region of memory 110 * 111 * - used only by /dev/kmem driver (mem.c) 112 */ 113 114 boolean_t 115 uvm_kernacc(caddr_t addr, size_t len, int rw) 116 { 117 boolean_t rv; 118 vaddr_t saddr, eaddr; 119 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 120 121 saddr = trunc_page((vaddr_t)addr); 122 eaddr = round_page((vaddr_t)addr + len); 123 vm_map_lock_read(kernel_map); 124 rv = uvm_map_checkprot(kernel_map, saddr, eaddr, prot); 125 vm_map_unlock_read(kernel_map); 126 127 return(rv); 128 } 129 130 #ifdef KGDB 131 /* 132 * Change protections on kernel pages from addr to addr+len 133 * (presumably so debugger can plant a breakpoint). 134 * 135 * We force the protection change at the pmap level. If we were 136 * to use vm_map_protect a change to allow writing would be lazily- 137 * applied meaning we would still take a protection fault, something 138 * we really don't want to do. It would also fragment the kernel 139 * map unnecessarily. We cannot use pmap_protect since it also won't 140 * enforce a write-enable request. Using pmap_enter is the only way 141 * we can ensure the change takes place properly. 142 */ 143 void 144 uvm_chgkprot(caddr_t addr, size_t len, int rw) 145 { 146 vm_prot_t prot; 147 paddr_t pa; 148 vaddr_t sva, eva; 149 150 prot = rw == B_READ ? VM_PROT_READ : VM_PROT_READ|VM_PROT_WRITE; 151 eva = round_page((vaddr_t)addr + len); 152 for (sva = trunc_page((vaddr_t)addr); sva < eva; sva += PAGE_SIZE) { 153 /* 154 * Extract physical address for the page. 155 */ 156 if (pmap_extract(pmap_kernel(), sva, &pa) == FALSE) 157 panic("chgkprot: invalid page"); 158 pmap_enter(pmap_kernel(), sva, pa, prot, PMAP_WIRED); 159 } 160 pmap_update(pmap_kernel()); 161 } 162 #endif 163 164 /* 165 * uvm_vslock: wire user memory for I/O 166 * 167 * - called from physio and sys___sysctl 168 * - XXXCDC: consider nuking this (or making it a macro?) 169 */ 170 171 int 172 uvm_vslock(struct proc *p, caddr_t addr, size_t len, vm_prot_t access_type) 173 { 174 struct vm_map *map; 175 vaddr_t start, end; 176 int error; 177 178 map = &p->p_vmspace->vm_map; 179 start = trunc_page((vaddr_t)addr); 180 end = round_page((vaddr_t)addr + len); 181 error = uvm_fault_wire(map, start, end, access_type, 0); 182 return error; 183 } 184 185 /* 186 * uvm_vsunlock: unwire user memory wired by uvm_vslock() 187 * 188 * - called from physio and sys___sysctl 189 * - XXXCDC: consider nuking this (or making it a macro?) 190 */ 191 192 void 193 uvm_vsunlock(struct proc *p, caddr_t addr, size_t len) 194 { 195 uvm_fault_unwire(&p->p_vmspace->vm_map, trunc_page((vaddr_t)addr), 196 round_page((vaddr_t)addr + len)); 197 } 198 199 /* 200 * uvm_proc_fork: fork a virtual address space 201 * 202 * - the address space is copied as per parent map's inherit values 203 */ 204 void 205 uvm_proc_fork(struct proc *p1, struct proc *p2, boolean_t shared) 206 { 207 208 if (shared == TRUE) { 209 p2->p_vmspace = NULL; 210 uvmspace_share(p1, p2); 211 } else { 212 p2->p_vmspace = uvmspace_fork(p1->p_vmspace); 213 } 214 215 cpu_proc_fork(p1, p2); 216 } 217 218 219 /* 220 * uvm_lwp_fork: fork a thread 221 * 222 * - a new "user" structure is allocated for the child process 223 * [filled in by MD layer...] 224 * - if specified, the child gets a new user stack described by 225 * stack and stacksize 226 * - NOTE: the kernel stack may be at a different location in the child 227 * process, and thus addresses of automatic variables may be invalid 228 * after cpu_lwp_fork returns in the child process. We do nothing here 229 * after cpu_lwp_fork returns. 230 * - XXXCDC: we need a way for this to return a failure value rather 231 * than just hang 232 */ 233 void 234 uvm_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize, 235 void (*func)(void *), void *arg) 236 { 237 struct user *up = l2->l_addr; 238 int error; 239 240 /* 241 * Wire down the U-area for the process, which contains the PCB 242 * and the kernel stack. Wired state is stored in l->l_flag's 243 * L_INMEM bit rather than in the vm_map_entry's wired count 244 * to prevent kernel_map fragmentation. If we reused a cached U-area, 245 * L_INMEM will already be set and we don't need to do anything. 246 * 247 * Note the kernel stack gets read/write accesses right off the bat. 248 */ 249 250 if ((l2->l_flag & L_INMEM) == 0) { 251 error = uvm_fault_wire(kernel_map, (vaddr_t)up, 252 (vaddr_t)up + USPACE, VM_PROT_READ | VM_PROT_WRITE, 0); 253 if (error) 254 panic("uvm_lwp_fork: uvm_fault_wire failed: %d", error); 255 #ifdef PMAP_UAREA 256 /* Tell the pmap this is a u-area mapping */ 257 PMAP_UAREA((vaddr_t)up); 258 #endif 259 l2->l_flag |= L_INMEM; 260 } 261 262 #ifdef KSTACK_CHECK_MAGIC 263 /* 264 * fill stack with magic number 265 */ 266 kstack_setup_magic(l2); 267 #endif 268 269 /* 270 * cpu_lwp_fork() copy and update the pcb, and make the child ready 271 * to run. If this is a normal user fork, the child will exit 272 * directly to user mode via child_return() on its first time 273 * slice and will not return here. If this is a kernel thread, 274 * the specified entry point will be executed. 275 */ 276 cpu_lwp_fork(l1, l2, stack, stacksize, func, arg); 277 } 278 279 /* 280 * uvm_uarea_alloc: allocate a u-area 281 */ 282 283 boolean_t 284 uvm_uarea_alloc(vaddr_t *uaddrp) 285 { 286 vaddr_t uaddr; 287 288 #ifndef USPACE_ALIGN 289 #define USPACE_ALIGN 0 290 #endif 291 292 simple_lock(&uvm_uareas_slock); 293 if (uvm_nuarea > 0) { 294 uaddr = (vaddr_t)uvm_uareas; 295 uvm_uareas = *(void **)uvm_uareas; 296 uvm_nuarea--; 297 simple_unlock(&uvm_uareas_slock); 298 *uaddrp = uaddr; 299 return TRUE; 300 } else { 301 simple_unlock(&uvm_uareas_slock); 302 *uaddrp = uvm_km_alloc(kernel_map, USPACE, USPACE_ALIGN, 303 UVM_KMF_PAGEABLE); 304 return FALSE; 305 } 306 } 307 308 /* 309 * uvm_uarea_free: free a u-area; never blocks 310 */ 311 312 static inline void 313 uvm_uarea_free(vaddr_t uaddr) 314 { 315 simple_lock(&uvm_uareas_slock); 316 *(void **)uaddr = uvm_uareas; 317 uvm_uareas = (void *)uaddr; 318 uvm_nuarea++; 319 simple_unlock(&uvm_uareas_slock); 320 } 321 322 /* 323 * uvm_uarea_drain: return memory of u-areas over limit 324 * back to system 325 */ 326 327 void 328 uvm_uarea_drain(boolean_t empty) 329 { 330 int leave = empty ? 0 : UVM_NUAREA_MAX; 331 vaddr_t uaddr; 332 333 if (uvm_nuarea <= leave) 334 return; 335 336 simple_lock(&uvm_uareas_slock); 337 while(uvm_nuarea > leave) { 338 uaddr = (vaddr_t)uvm_uareas; 339 uvm_uareas = *(void **)uvm_uareas; 340 uvm_nuarea--; 341 simple_unlock(&uvm_uareas_slock); 342 uvm_km_free(kernel_map, uaddr, USPACE, UVM_KMF_PAGEABLE); 343 simple_lock(&uvm_uareas_slock); 344 } 345 simple_unlock(&uvm_uareas_slock); 346 } 347 348 /* 349 * uvm_exit: exit a virtual address space 350 * 351 * - the process passed to us is a dead (pre-zombie) process; we 352 * are running on a different context now (the reaper). 353 * - borrow proc0's address space because freeing the vmspace 354 * of the dead process may block. 355 */ 356 357 void 358 uvm_proc_exit(struct proc *p) 359 { 360 struct lwp *l = curlwp; /* XXX */ 361 struct vmspace *ovm; 362 363 KASSERT(p == l->l_proc); 364 ovm = p->p_vmspace; 365 366 /* 367 * borrow proc0's address space. 368 */ 369 pmap_deactivate(l); 370 p->p_vmspace = proc0.p_vmspace; 371 pmap_activate(l); 372 373 uvmspace_free(ovm); 374 } 375 376 void 377 uvm_lwp_exit(struct lwp *l) 378 { 379 vaddr_t va = (vaddr_t)l->l_addr; 380 381 l->l_flag &= ~L_INMEM; 382 uvm_uarea_free(va); 383 l->l_addr = NULL; 384 } 385 386 /* 387 * uvm_init_limit: init per-process VM limits 388 * 389 * - called for process 0 and then inherited by all others. 390 */ 391 392 void 393 uvm_init_limits(struct proc *p) 394 { 395 396 /* 397 * Set up the initial limits on process VM. Set the maximum 398 * resident set size to be all of (reasonably) available memory. 399 * This causes any single, large process to start random page 400 * replacement once it fills memory. 401 */ 402 403 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 404 p->p_rlimit[RLIMIT_STACK].rlim_max = maxsmap; 405 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; 406 p->p_rlimit[RLIMIT_DATA].rlim_max = maxdmap; 407 p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(uvmexp.free); 408 } 409 410 #ifdef DEBUG 411 int enableswap = 1; 412 int swapdebug = 0; 413 #define SDB_FOLLOW 1 414 #define SDB_SWAPIN 2 415 #define SDB_SWAPOUT 4 416 #endif 417 418 /* 419 * uvm_swapin: swap in a process's u-area. 420 */ 421 422 void 423 uvm_swapin(struct lwp *l) 424 { 425 vaddr_t addr; 426 int s, error; 427 428 addr = (vaddr_t)l->l_addr; 429 /* make L_INMEM true */ 430 error = uvm_fault_wire(kernel_map, addr, addr + USPACE, 431 VM_PROT_READ | VM_PROT_WRITE, 0); 432 if (error) { 433 panic("uvm_swapin: rewiring stack failed: %d", error); 434 } 435 436 /* 437 * Some architectures need to be notified when the user area has 438 * moved to new physical page(s) (e.g. see mips/mips/vm_machdep.c). 439 */ 440 cpu_swapin(l); 441 SCHED_LOCK(s); 442 if (l->l_stat == LSRUN) 443 setrunqueue(l); 444 l->l_flag |= L_INMEM; 445 SCHED_UNLOCK(s); 446 l->l_swtime = 0; 447 ++uvmexp.swapins; 448 } 449 450 /* 451 * uvm_scheduler: process zero main loop 452 * 453 * - attempt to swapin every swaped-out, runnable process in order of 454 * priority. 455 * - if not enough memory, wake the pagedaemon and let it clear space. 456 */ 457 458 void 459 uvm_scheduler(void) 460 { 461 struct lwp *l, *ll; 462 int pri; 463 int ppri; 464 465 loop: 466 #ifdef DEBUG 467 while (!enableswap) 468 tsleep(&proc0, PVM, "noswap", 0); 469 #endif 470 ll = NULL; /* process to choose */ 471 ppri = INT_MIN; /* its priority */ 472 proclist_lock_read(); 473 474 LIST_FOREACH(l, &alllwp, l_list) { 475 /* is it a runnable swapped out process? */ 476 if (l->l_stat == LSRUN && (l->l_flag & L_INMEM) == 0) { 477 pri = l->l_swtime + l->l_slptime - 478 (l->l_proc->p_nice - NZERO) * 8; 479 if (pri > ppri) { /* higher priority? remember it. */ 480 ll = l; 481 ppri = pri; 482 } 483 } 484 } 485 /* 486 * XXXSMP: possible unlock/sleep race between here and the 487 * "scheduler" tsleep below.. 488 */ 489 proclist_unlock_read(); 490 491 #ifdef DEBUG 492 if (swapdebug & SDB_FOLLOW) 493 printf("scheduler: running, procp %p pri %d\n", ll, ppri); 494 #endif 495 /* 496 * Nothing to do, back to sleep 497 */ 498 if ((l = ll) == NULL) { 499 tsleep(&proc0, PVM, "scheduler", 0); 500 goto loop; 501 } 502 503 /* 504 * we have found swapped out process which we would like to bring 505 * back in. 506 * 507 * XXX: this part is really bogus cuz we could deadlock on memory 508 * despite our feeble check 509 */ 510 if (uvmexp.free > atop(USPACE)) { 511 #ifdef DEBUG 512 if (swapdebug & SDB_SWAPIN) 513 printf("swapin: pid %d(%s)@%p, pri %d free %d\n", 514 l->l_proc->p_pid, l->l_proc->p_comm, l->l_addr, ppri, uvmexp.free); 515 #endif 516 uvm_swapin(l); 517 goto loop; 518 } 519 /* 520 * not enough memory, jab the pageout daemon and wait til the coast 521 * is clear 522 */ 523 #ifdef DEBUG 524 if (swapdebug & SDB_FOLLOW) 525 printf("scheduler: no room for pid %d(%s), free %d\n", 526 l->l_proc->p_pid, l->l_proc->p_comm, uvmexp.free); 527 #endif 528 uvm_wait("schedpwait"); 529 #ifdef DEBUG 530 if (swapdebug & SDB_FOLLOW) 531 printf("scheduler: room again, free %d\n", uvmexp.free); 532 #endif 533 goto loop; 534 } 535 536 /* 537 * swappable: is LWP "l" swappable? 538 */ 539 540 #define swappable(l) \ 541 (((l)->l_flag & (L_INMEM)) && \ 542 ((((l)->l_proc->p_flag) & (P_SYSTEM | P_WEXIT)) == 0) && \ 543 (l)->l_holdcnt == 0) 544 545 /* 546 * swapout_threads: find threads that can be swapped and unwire their 547 * u-areas. 548 * 549 * - called by the pagedaemon 550 * - try and swap at least one processs 551 * - processes that are sleeping or stopped for maxslp or more seconds 552 * are swapped... otherwise the longest-sleeping or stopped process 553 * is swapped, otherwise the longest resident process... 554 */ 555 556 void 557 uvm_swapout_threads(void) 558 { 559 struct lwp *l; 560 struct lwp *outl, *outl2; 561 int outpri, outpri2; 562 int didswap = 0; 563 extern int maxslp; 564 /* XXXCDC: should move off to uvmexp. or uvm., also in uvm_meter */ 565 566 #ifdef DEBUG 567 if (!enableswap) 568 return; 569 #endif 570 571 /* 572 * outl/outpri : stop/sleep thread with largest sleeptime < maxslp 573 * outl2/outpri2: the longest resident thread (its swap time) 574 */ 575 outl = outl2 = NULL; 576 outpri = outpri2 = 0; 577 proclist_lock_read(); 578 LIST_FOREACH(l, &alllwp, l_list) { 579 KASSERT(l->l_proc != NULL); 580 if (!swappable(l)) 581 continue; 582 switch (l->l_stat) { 583 case LSONPROC: 584 continue; 585 586 case LSRUN: 587 if (l->l_swtime > outpri2) { 588 outl2 = l; 589 outpri2 = l->l_swtime; 590 } 591 continue; 592 593 case LSSLEEP: 594 case LSSTOP: 595 if (l->l_slptime >= maxslp) { 596 uvm_swapout(l); 597 didswap++; 598 } else if (l->l_slptime > outpri) { 599 outl = l; 600 outpri = l->l_slptime; 601 } 602 continue; 603 } 604 } 605 proclist_unlock_read(); 606 607 /* 608 * If we didn't get rid of any real duds, toss out the next most 609 * likely sleeping/stopped or running candidate. We only do this 610 * if we are real low on memory since we don't gain much by doing 611 * it (USPACE bytes). 612 */ 613 if (didswap == 0 && uvmexp.free <= atop(round_page(USPACE))) { 614 if ((l = outl) == NULL) 615 l = outl2; 616 #ifdef DEBUG 617 if (swapdebug & SDB_SWAPOUT) 618 printf("swapout_threads: no duds, try procp %p\n", l); 619 #endif 620 if (l) 621 uvm_swapout(l); 622 } 623 } 624 625 /* 626 * uvm_swapout: swap out lwp "l" 627 * 628 * - currently "swapout" means "unwire U-area" and "pmap_collect()" 629 * the pmap. 630 * - XXXCDC: should deactivate all process' private anonymous memory 631 */ 632 633 static void 634 uvm_swapout(struct lwp *l) 635 { 636 vaddr_t addr; 637 int s; 638 struct proc *p = l->l_proc; 639 640 #ifdef DEBUG 641 if (swapdebug & SDB_SWAPOUT) 642 printf("swapout: lid %d.%d(%s)@%p, stat %x pri %d free %d\n", 643 p->p_pid, l->l_lid, p->p_comm, l->l_addr, l->l_stat, 644 l->l_slptime, uvmexp.free); 645 #endif 646 647 /* 648 * Mark it as (potentially) swapped out. 649 */ 650 SCHED_LOCK(s); 651 if (l->l_stat == LSONPROC) { 652 KDASSERT(l->l_cpu != curcpu()); 653 SCHED_UNLOCK(s); 654 return; 655 } 656 l->l_flag &= ~L_INMEM; 657 if (l->l_stat == LSRUN) 658 remrunqueue(l); 659 SCHED_UNLOCK(s); 660 l->l_swtime = 0; 661 p->p_stats->p_ru.ru_nswap++; 662 ++uvmexp.swapouts; 663 664 /* 665 * Do any machine-specific actions necessary before swapout. 666 * This can include saving floating point state, etc. 667 */ 668 cpu_swapout(l); 669 670 /* 671 * Unwire the to-be-swapped process's user struct and kernel stack. 672 */ 673 addr = (vaddr_t)l->l_addr; 674 uvm_fault_unwire(kernel_map, addr, addr + USPACE); /* !L_INMEM */ 675 pmap_collect(vm_map_pmap(&p->p_vmspace->vm_map)); 676 } 677 678 /* 679 * uvm_coredump_walkmap: walk a process's map for the purpose of dumping 680 * a core file. 681 */ 682 683 int 684 uvm_coredump_walkmap(struct proc *p, void *iocookie, 685 int (*func)(struct proc *, void *, struct uvm_coredump_state *), 686 void *cookie) 687 { 688 struct uvm_coredump_state state; 689 struct vmspace *vm = p->p_vmspace; 690 struct vm_map *map = &vm->vm_map; 691 struct vm_map_entry *entry; 692 int error; 693 694 entry = NULL; 695 vm_map_lock_read(map); 696 state.end = 0; 697 for (;;) { 698 if (entry == NULL) 699 entry = map->header.next; 700 else if (!uvm_map_lookup_entry(map, state.end, &entry)) 701 entry = entry->next; 702 if (entry == &map->header) 703 break; 704 705 state.cookie = cookie; 706 if (state.end > entry->start) { 707 state.start = state.end; 708 } else { 709 state.start = entry->start; 710 } 711 state.realend = entry->end; 712 state.end = entry->end; 713 state.prot = entry->protection; 714 state.flags = 0; 715 716 /* 717 * Dump the region unless one of the following is true: 718 * 719 * (1) the region has neither object nor amap behind it 720 * (ie. it has never been accessed). 721 * 722 * (2) the region has no amap and is read-only 723 * (eg. an executable text section). 724 * 725 * (3) the region's object is a device. 726 * 727 * (4) the region is unreadable by the process. 728 */ 729 730 KASSERT(!UVM_ET_ISSUBMAP(entry)); 731 KASSERT(state.start < VM_MAXUSER_ADDRESS); 732 KASSERT(state.end <= VM_MAXUSER_ADDRESS); 733 if (entry->object.uvm_obj == NULL && 734 entry->aref.ar_amap == NULL) { 735 state.realend = state.start; 736 } else if ((entry->protection & VM_PROT_WRITE) == 0 && 737 entry->aref.ar_amap == NULL) { 738 state.realend = state.start; 739 } else if (entry->object.uvm_obj != NULL && 740 UVM_OBJ_IS_DEVICE(entry->object.uvm_obj)) { 741 state.realend = state.start; 742 } else if ((entry->protection & VM_PROT_READ) == 0) { 743 state.realend = state.start; 744 } else { 745 if (state.start >= (vaddr_t)vm->vm_maxsaddr) 746 state.flags |= UVM_COREDUMP_STACK; 747 748 /* 749 * If this an anonymous entry, only dump instantiated 750 * pages. 751 */ 752 if (entry->object.uvm_obj == NULL) { 753 vaddr_t end; 754 755 amap_lock(entry->aref.ar_amap); 756 for (end = state.start; 757 end < state.end; end += PAGE_SIZE) { 758 struct vm_anon *anon; 759 anon = amap_lookup(&entry->aref, 760 end - entry->start); 761 /* 762 * If we have already encountered an 763 * uninstantiated page, stop at the 764 * first instantied page. 765 */ 766 if (anon != NULL && 767 state.realend != state.end) { 768 state.end = end; 769 break; 770 } 771 772 /* 773 * If this page is the first 774 * uninstantiated page, mark this as 775 * the real ending point. Continue to 776 * counting uninstantiated pages. 777 */ 778 if (anon == NULL && 779 state.realend == state.end) { 780 state.realend = end; 781 } 782 } 783 amap_unlock(entry->aref.ar_amap); 784 } 785 } 786 787 788 vm_map_unlock_read(map); 789 error = (*func)(p, iocookie, &state); 790 if (error) 791 return (error); 792 vm_map_lock_read(map); 793 } 794 vm_map_unlock_read(map); 795 796 return (0); 797 } 798