1 /* $NetBSD: uvm_glue.c,v 1.92 2005/12/24 23:41:34 perry 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 1.92 2005/12/24 23:41:34 perry 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, VM_FAULT_WIRE, access_type); 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_FAULT_WIRE, 253 VM_PROT_READ | VM_PROT_WRITE); 254 if (error) 255 panic("uvm_lwp_fork: uvm_fault_wire failed: %d", error); 256 #ifdef PMAP_UAREA 257 /* Tell the pmap this is a u-area mapping */ 258 PMAP_UAREA((vaddr_t)up); 259 #endif 260 l2->l_flag |= L_INMEM; 261 } 262 263 #ifdef KSTACK_CHECK_MAGIC 264 /* 265 * fill stack with magic number 266 */ 267 kstack_setup_magic(l2); 268 #endif 269 270 /* 271 * cpu_lwp_fork() copy and update the pcb, and make the child ready 272 * to run. If this is a normal user fork, the child will exit 273 * directly to user mode via child_return() on its first time 274 * slice and will not return here. If this is a kernel thread, 275 * the specified entry point will be executed. 276 */ 277 cpu_lwp_fork(l1, l2, stack, stacksize, func, arg); 278 } 279 280 /* 281 * uvm_uarea_alloc: allocate a u-area 282 */ 283 284 boolean_t 285 uvm_uarea_alloc(vaddr_t *uaddrp) 286 { 287 vaddr_t uaddr; 288 289 #ifndef USPACE_ALIGN 290 #define USPACE_ALIGN 0 291 #endif 292 293 simple_lock(&uvm_uareas_slock); 294 if (uvm_nuarea > 0) { 295 uaddr = (vaddr_t)uvm_uareas; 296 uvm_uareas = *(void **)uvm_uareas; 297 uvm_nuarea--; 298 simple_unlock(&uvm_uareas_slock); 299 *uaddrp = uaddr; 300 return TRUE; 301 } else { 302 simple_unlock(&uvm_uareas_slock); 303 *uaddrp = uvm_km_alloc(kernel_map, USPACE, USPACE_ALIGN, 304 UVM_KMF_PAGEABLE); 305 return FALSE; 306 } 307 } 308 309 /* 310 * uvm_uarea_free: free a u-area; never blocks 311 */ 312 313 static inline void 314 uvm_uarea_free(vaddr_t uaddr) 315 { 316 simple_lock(&uvm_uareas_slock); 317 *(void **)uaddr = uvm_uareas; 318 uvm_uareas = (void *)uaddr; 319 uvm_nuarea++; 320 simple_unlock(&uvm_uareas_slock); 321 } 322 323 /* 324 * uvm_uarea_drain: return memory of u-areas over limit 325 * back to system 326 */ 327 328 void 329 uvm_uarea_drain(boolean_t empty) 330 { 331 int leave = empty ? 0 : UVM_NUAREA_MAX; 332 vaddr_t uaddr; 333 334 if (uvm_nuarea <= leave) 335 return; 336 337 simple_lock(&uvm_uareas_slock); 338 while(uvm_nuarea > leave) { 339 uaddr = (vaddr_t)uvm_uareas; 340 uvm_uareas = *(void **)uvm_uareas; 341 uvm_nuarea--; 342 simple_unlock(&uvm_uareas_slock); 343 uvm_km_free(kernel_map, uaddr, USPACE, UVM_KMF_PAGEABLE); 344 simple_lock(&uvm_uareas_slock); 345 } 346 simple_unlock(&uvm_uareas_slock); 347 } 348 349 /* 350 * uvm_exit: exit a virtual address space 351 * 352 * - the process passed to us is a dead (pre-zombie) process; we 353 * are running on a different context now (the reaper). 354 * - borrow proc0's address space because freeing the vmspace 355 * of the dead process may block. 356 */ 357 358 void 359 uvm_proc_exit(struct proc *p) 360 { 361 struct lwp *l = curlwp; /* XXX */ 362 struct vmspace *ovm; 363 364 KASSERT(p == l->l_proc); 365 ovm = p->p_vmspace; 366 367 /* 368 * borrow proc0's address space. 369 */ 370 pmap_deactivate(l); 371 p->p_vmspace = proc0.p_vmspace; 372 pmap_activate(l); 373 374 uvmspace_free(ovm); 375 } 376 377 void 378 uvm_lwp_exit(struct lwp *l) 379 { 380 vaddr_t va = (vaddr_t)l->l_addr; 381 382 l->l_flag &= ~L_INMEM; 383 uvm_uarea_free(va); 384 l->l_addr = NULL; 385 } 386 387 /* 388 * uvm_init_limit: init per-process VM limits 389 * 390 * - called for process 0 and then inherited by all others. 391 */ 392 393 void 394 uvm_init_limits(struct proc *p) 395 { 396 397 /* 398 * Set up the initial limits on process VM. Set the maximum 399 * resident set size to be all of (reasonably) available memory. 400 * This causes any single, large process to start random page 401 * replacement once it fills memory. 402 */ 403 404 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 405 p->p_rlimit[RLIMIT_STACK].rlim_max = maxsmap; 406 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; 407 p->p_rlimit[RLIMIT_DATA].rlim_max = maxdmap; 408 p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(uvmexp.free); 409 } 410 411 #ifdef DEBUG 412 int enableswap = 1; 413 int swapdebug = 0; 414 #define SDB_FOLLOW 1 415 #define SDB_SWAPIN 2 416 #define SDB_SWAPOUT 4 417 #endif 418 419 /* 420 * uvm_swapin: swap in a process's u-area. 421 */ 422 423 void 424 uvm_swapin(struct lwp *l) 425 { 426 vaddr_t addr; 427 int s, error; 428 429 addr = (vaddr_t)l->l_addr; 430 /* make L_INMEM true */ 431 error = uvm_fault_wire(kernel_map, addr, addr + USPACE, VM_FAULT_WIRE, 432 VM_PROT_READ | VM_PROT_WRITE); 433 if (error) { 434 panic("uvm_swapin: rewiring stack failed: %d", error); 435 } 436 437 /* 438 * Some architectures need to be notified when the user area has 439 * moved to new physical page(s) (e.g. see mips/mips/vm_machdep.c). 440 */ 441 cpu_swapin(l); 442 SCHED_LOCK(s); 443 if (l->l_stat == LSRUN) 444 setrunqueue(l); 445 l->l_flag |= L_INMEM; 446 SCHED_UNLOCK(s); 447 l->l_swtime = 0; 448 ++uvmexp.swapins; 449 } 450 451 /* 452 * uvm_scheduler: process zero main loop 453 * 454 * - attempt to swapin every swaped-out, runnable process in order of 455 * priority. 456 * - if not enough memory, wake the pagedaemon and let it clear space. 457 */ 458 459 void 460 uvm_scheduler(void) 461 { 462 struct lwp *l, *ll; 463 int pri; 464 int ppri; 465 466 loop: 467 #ifdef DEBUG 468 while (!enableswap) 469 tsleep(&proc0, PVM, "noswap", 0); 470 #endif 471 ll = NULL; /* process to choose */ 472 ppri = INT_MIN; /* its priority */ 473 proclist_lock_read(); 474 475 LIST_FOREACH(l, &alllwp, l_list) { 476 /* is it a runnable swapped out process? */ 477 if (l->l_stat == LSRUN && (l->l_flag & L_INMEM) == 0) { 478 pri = l->l_swtime + l->l_slptime - 479 (l->l_proc->p_nice - NZERO) * 8; 480 if (pri > ppri) { /* higher priority? remember it. */ 481 ll = l; 482 ppri = pri; 483 } 484 } 485 } 486 /* 487 * XXXSMP: possible unlock/sleep race between here and the 488 * "scheduler" tsleep below.. 489 */ 490 proclist_unlock_read(); 491 492 #ifdef DEBUG 493 if (swapdebug & SDB_FOLLOW) 494 printf("scheduler: running, procp %p pri %d\n", ll, ppri); 495 #endif 496 /* 497 * Nothing to do, back to sleep 498 */ 499 if ((l = ll) == NULL) { 500 tsleep(&proc0, PVM, "scheduler", 0); 501 goto loop; 502 } 503 504 /* 505 * we have found swapped out process which we would like to bring 506 * back in. 507 * 508 * XXX: this part is really bogus cuz we could deadlock on memory 509 * despite our feeble check 510 */ 511 if (uvmexp.free > atop(USPACE)) { 512 #ifdef DEBUG 513 if (swapdebug & SDB_SWAPIN) 514 printf("swapin: pid %d(%s)@%p, pri %d free %d\n", 515 l->l_proc->p_pid, l->l_proc->p_comm, l->l_addr, ppri, uvmexp.free); 516 #endif 517 uvm_swapin(l); 518 goto loop; 519 } 520 /* 521 * not enough memory, jab the pageout daemon and wait til the coast 522 * is clear 523 */ 524 #ifdef DEBUG 525 if (swapdebug & SDB_FOLLOW) 526 printf("scheduler: no room for pid %d(%s), free %d\n", 527 l->l_proc->p_pid, l->l_proc->p_comm, uvmexp.free); 528 #endif 529 uvm_wait("schedpwait"); 530 #ifdef DEBUG 531 if (swapdebug & SDB_FOLLOW) 532 printf("scheduler: room again, free %d\n", uvmexp.free); 533 #endif 534 goto loop; 535 } 536 537 /* 538 * swappable: is LWP "l" swappable? 539 */ 540 541 #define swappable(l) \ 542 (((l)->l_flag & (L_INMEM)) && \ 543 ((((l)->l_proc->p_flag) & (P_SYSTEM | P_WEXIT)) == 0) && \ 544 (l)->l_holdcnt == 0) 545 546 /* 547 * swapout_threads: find threads that can be swapped and unwire their 548 * u-areas. 549 * 550 * - called by the pagedaemon 551 * - try and swap at least one processs 552 * - processes that are sleeping or stopped for maxslp or more seconds 553 * are swapped... otherwise the longest-sleeping or stopped process 554 * is swapped, otherwise the longest resident process... 555 */ 556 557 void 558 uvm_swapout_threads(void) 559 { 560 struct lwp *l; 561 struct lwp *outl, *outl2; 562 int outpri, outpri2; 563 int didswap = 0; 564 extern int maxslp; 565 /* XXXCDC: should move off to uvmexp. or uvm., also in uvm_meter */ 566 567 #ifdef DEBUG 568 if (!enableswap) 569 return; 570 #endif 571 572 /* 573 * outl/outpri : stop/sleep thread with largest sleeptime < maxslp 574 * outl2/outpri2: the longest resident thread (its swap time) 575 */ 576 outl = outl2 = NULL; 577 outpri = outpri2 = 0; 578 proclist_lock_read(); 579 LIST_FOREACH(l, &alllwp, l_list) { 580 KASSERT(l->l_proc != NULL); 581 if (!swappable(l)) 582 continue; 583 switch (l->l_stat) { 584 case LSONPROC: 585 continue; 586 587 case LSRUN: 588 if (l->l_swtime > outpri2) { 589 outl2 = l; 590 outpri2 = l->l_swtime; 591 } 592 continue; 593 594 case LSSLEEP: 595 case LSSTOP: 596 if (l->l_slptime >= maxslp) { 597 uvm_swapout(l); 598 didswap++; 599 } else if (l->l_slptime > outpri) { 600 outl = l; 601 outpri = l->l_slptime; 602 } 603 continue; 604 } 605 } 606 proclist_unlock_read(); 607 608 /* 609 * If we didn't get rid of any real duds, toss out the next most 610 * likely sleeping/stopped or running candidate. We only do this 611 * if we are real low on memory since we don't gain much by doing 612 * it (USPACE bytes). 613 */ 614 if (didswap == 0 && uvmexp.free <= atop(round_page(USPACE))) { 615 if ((l = outl) == NULL) 616 l = outl2; 617 #ifdef DEBUG 618 if (swapdebug & SDB_SWAPOUT) 619 printf("swapout_threads: no duds, try procp %p\n", l); 620 #endif 621 if (l) 622 uvm_swapout(l); 623 } 624 } 625 626 /* 627 * uvm_swapout: swap out lwp "l" 628 * 629 * - currently "swapout" means "unwire U-area" and "pmap_collect()" 630 * the pmap. 631 * - XXXCDC: should deactivate all process' private anonymous memory 632 */ 633 634 static void 635 uvm_swapout(struct lwp *l) 636 { 637 vaddr_t addr; 638 int s; 639 struct proc *p = l->l_proc; 640 641 #ifdef DEBUG 642 if (swapdebug & SDB_SWAPOUT) 643 printf("swapout: lid %d.%d(%s)@%p, stat %x pri %d free %d\n", 644 p->p_pid, l->l_lid, p->p_comm, l->l_addr, l->l_stat, 645 l->l_slptime, uvmexp.free); 646 #endif 647 648 /* 649 * Mark it as (potentially) swapped out. 650 */ 651 SCHED_LOCK(s); 652 if (l->l_stat == LSONPROC) { 653 KDASSERT(l->l_cpu != curcpu()); 654 SCHED_UNLOCK(s); 655 return; 656 } 657 l->l_flag &= ~L_INMEM; 658 if (l->l_stat == LSRUN) 659 remrunqueue(l); 660 SCHED_UNLOCK(s); 661 l->l_swtime = 0; 662 p->p_stats->p_ru.ru_nswap++; 663 ++uvmexp.swapouts; 664 665 /* 666 * Do any machine-specific actions necessary before swapout. 667 * This can include saving floating point state, etc. 668 */ 669 cpu_swapout(l); 670 671 /* 672 * Unwire the to-be-swapped process's user struct and kernel stack. 673 */ 674 addr = (vaddr_t)l->l_addr; 675 uvm_fault_unwire(kernel_map, addr, addr + USPACE); /* !L_INMEM */ 676 pmap_collect(vm_map_pmap(&p->p_vmspace->vm_map)); 677 } 678 679 /* 680 * uvm_coredump_walkmap: walk a process's map for the purpose of dumping 681 * a core file. 682 */ 683 684 int 685 uvm_coredump_walkmap(struct proc *p, void *iocookie, 686 int (*func)(struct proc *, void *, struct uvm_coredump_state *), 687 void *cookie) 688 { 689 struct uvm_coredump_state state; 690 struct vmspace *vm = p->p_vmspace; 691 struct vm_map *map = &vm->vm_map; 692 struct vm_map_entry *entry; 693 int error; 694 695 entry = NULL; 696 vm_map_lock_read(map); 697 state.end = 0; 698 for (;;) { 699 if (entry == NULL) 700 entry = map->header.next; 701 else if (!uvm_map_lookup_entry(map, state.end, &entry)) 702 entry = entry->next; 703 if (entry == &map->header) 704 break; 705 706 state.cookie = cookie; 707 if (state.end > entry->start) { 708 state.start = state.end; 709 } else { 710 state.start = entry->start; 711 } 712 state.realend = entry->end; 713 state.end = entry->end; 714 state.prot = entry->protection; 715 state.flags = 0; 716 717 /* 718 * Dump the region unless one of the following is true: 719 * 720 * (1) the region has neither object nor amap behind it 721 * (ie. it has never been accessed). 722 * 723 * (2) the region has no amap and is read-only 724 * (eg. an executable text section). 725 * 726 * (3) the region's object is a device. 727 * 728 * (4) the region is unreadable by the process. 729 */ 730 731 KASSERT(!UVM_ET_ISSUBMAP(entry)); 732 KASSERT(state.start < VM_MAXUSER_ADDRESS); 733 KASSERT(state.end <= VM_MAXUSER_ADDRESS); 734 if (entry->object.uvm_obj == NULL && 735 entry->aref.ar_amap == NULL) { 736 state.realend = state.start; 737 } else if ((entry->protection & VM_PROT_WRITE) == 0 && 738 entry->aref.ar_amap == NULL) { 739 state.realend = state.start; 740 } else if (entry->object.uvm_obj != NULL && 741 UVM_OBJ_IS_DEVICE(entry->object.uvm_obj)) { 742 state.realend = state.start; 743 } else if ((entry->protection & VM_PROT_READ) == 0) { 744 state.realend = state.start; 745 } else { 746 if (state.start >= (vaddr_t)vm->vm_maxsaddr) 747 state.flags |= UVM_COREDUMP_STACK; 748 749 /* 750 * If this an anonymous entry, only dump instantiated 751 * pages. 752 */ 753 if (entry->object.uvm_obj == NULL) { 754 vaddr_t end; 755 756 amap_lock(entry->aref.ar_amap); 757 for (end = state.start; 758 end < state.end; end += PAGE_SIZE) { 759 struct vm_anon *anon; 760 anon = amap_lookup(&entry->aref, 761 end - entry->start); 762 /* 763 * If we have already encountered an 764 * uninstantiated page, stop at the 765 * first instantied page. 766 */ 767 if (anon != NULL && 768 state.realend != state.end) { 769 state.end = end; 770 break; 771 } 772 773 /* 774 * If this page is the first 775 * uninstantiated page, mark this as 776 * the real ending point. Continue to 777 * counting uninstantiated pages. 778 */ 779 if (anon == NULL && 780 state.realend == state.end) { 781 state.realend = end; 782 } 783 } 784 amap_unlock(entry->aref.ar_amap); 785 } 786 } 787 788 789 vm_map_unlock_read(map); 790 error = (*func)(p, iocookie, &state); 791 if (error) 792 return (error); 793 vm_map_lock_read(map); 794 } 795 vm_map_unlock_read(map); 796 797 return (0); 798 } 799