trap-v4.c revision 314526
1/* $NetBSD: fault.c,v 1.45 2003/11/20 14:44:36 scw Exp $ */ 2 3/*- 4 * Copyright 2004 Olivier Houchard 5 * Copyright 2003 Wasabi Systems, Inc. 6 * All rights reserved. 7 * 8 * Written by Steve C. Woodford for Wasabi Systems, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed for the NetBSD Project by 21 * Wasabi Systems, Inc. 22 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 23 * or promote products derived from this software without specific prior 24 * written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38/*- 39 * Copyright (c) 1994-1997 Mark Brinicombe. 40 * Copyright (c) 1994 Brini. 41 * All rights reserved. 42 * 43 * This code is derived from software written for Brini by Mark Brinicombe 44 * 45 * Redistribution and use in source and binary forms, with or without 46 * modification, are permitted provided that the following conditions 47 * are met: 48 * 1. Redistributions of source code must retain the above copyright 49 * notice, this list of conditions and the following disclaimer. 50 * 2. Redistributions in binary form must reproduce the above copyright 51 * notice, this list of conditions and the following disclaimer in the 52 * documentation and/or other materials provided with the distribution. 53 * 3. All advertising materials mentioning features or use of this software 54 * must display the following acknowledgement: 55 * This product includes software developed by Brini. 56 * 4. The name of the company nor the name of the author may be used to 57 * endorse or promote products derived from this software without specific 58 * prior written permission. 59 * 60 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED 61 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 62 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 63 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 64 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 65 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 66 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 70 * SUCH DAMAGE. 71 * 72 * RiscBSD kernel project 73 * 74 * fault.c 75 * 76 * Fault handlers 77 * 78 * Created : 28/11/94 79 */ 80 81#include <sys/cdefs.h> 82__FBSDID("$FreeBSD: stable/11/sys/arm/arm/trap-v4.c 314526 2017-03-01 23:35:40Z ian $"); 83 84#include <sys/param.h> 85#include <sys/systm.h> 86#include <sys/proc.h> 87#include <sys/lock.h> 88#include <sys/mutex.h> 89#include <sys/signalvar.h> 90 91#include <vm/vm.h> 92#include <vm/pmap.h> 93#include <vm/vm_kern.h> 94#include <vm/vm_map.h> 95#include <vm/vm_extern.h> 96 97#include <machine/cpu.h> 98#include <machine/frame.h> 99#include <machine/machdep.h> 100#include <machine/pcb.h> 101#include <machine/vmparam.h> 102 103#ifdef KDB 104#include <sys/kdb.h> 105#endif 106 107#ifdef KDTRACE_HOOKS 108#include <sys/dtrace_bsd.h> 109#endif 110 111#define ReadWord(a) (*((volatile unsigned int *)(a))) 112 113#ifdef DEBUG 114int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 115#endif 116 117struct ksig { 118 int signb; 119 u_long code; 120}; 121struct data_abort { 122 int (*func)(struct trapframe *, u_int, u_int, struct thread *, 123 struct ksig *); 124 const char *desc; 125}; 126 127static int dab_fatal(struct trapframe *, u_int, u_int, struct thread *, 128 struct ksig *); 129static int dab_align(struct trapframe *, u_int, u_int, struct thread *, 130 struct ksig *); 131static int dab_buserr(struct trapframe *, u_int, u_int, struct thread *, 132 struct ksig *); 133static void prefetch_abort_handler(struct trapframe *); 134 135static const struct data_abort data_aborts[] = { 136 {dab_fatal, "Vector Exception"}, 137 {dab_align, "Alignment Fault 1"}, 138 {dab_fatal, "Terminal Exception"}, 139 {dab_align, "Alignment Fault 3"}, 140 {dab_buserr, "External Linefetch Abort (S)"}, 141 {NULL, "Translation Fault (S)"}, 142 {dab_buserr, "External Linefetch Abort (P)"}, 143 {NULL, "Translation Fault (P)"}, 144 {dab_buserr, "External Non-Linefetch Abort (S)"}, 145 {NULL, "Domain Fault (S)"}, 146 {dab_buserr, "External Non-Linefetch Abort (P)"}, 147 {NULL, "Domain Fault (P)"}, 148 {dab_buserr, "External Translation Abort (L1)"}, 149 {NULL, "Permission Fault (S)"}, 150 {dab_buserr, "External Translation Abort (L2)"}, 151 {NULL, "Permission Fault (P)"} 152}; 153 154/* Determine if a fault came from user mode */ 155#define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE) 156 157/* Determine if 'x' is a permission fault */ 158#define IS_PERMISSION_FAULT(x) \ 159 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 160 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 161 162static __inline void 163call_trapsignal(struct thread *td, int sig, u_long code) 164{ 165 ksiginfo_t ksi; 166 167 ksiginfo_init_trap(&ksi); 168 ksi.ksi_signo = sig; 169 ksi.ksi_code = (int)code; 170 trapsignal(td, &ksi); 171} 172 173void 174abort_handler(struct trapframe *tf, int type) 175{ 176 struct vm_map *map; 177 struct pcb *pcb; 178 struct thread *td; 179 u_int user, far, fsr; 180 vm_prot_t ftype; 181 void *onfault; 182 vm_offset_t va; 183 int error = 0; 184 struct ksig ksig; 185 struct proc *p; 186 187 if (type == 1) 188 return (prefetch_abort_handler(tf)); 189 190 /* Grab FAR/FSR before enabling interrupts */ 191 far = cpu_faultaddress(); 192 fsr = cpu_faultstatus(); 193#if 0 194 printf("data abort: fault address=%p (from pc=%p lr=%p)\n", 195 (void*)far, (void*)tf->tf_pc, (void*)tf->tf_svc_lr); 196#endif 197 198 /* Update vmmeter statistics */ 199#if 0 200 vmexp.traps++; 201#endif 202 203 td = curthread; 204 p = td->td_proc; 205 206 PCPU_INC(cnt.v_trap); 207 /* Data abort came from user mode? */ 208 user = TRAP_USERMODE(tf); 209 210 if (user) { 211 td->td_pticks = 0; 212 td->td_frame = tf; 213 if (td->td_cowgen != td->td_proc->p_cowgen) 214 thread_cow_update(td); 215 216 } 217 /* Grab the current pcb */ 218 pcb = td->td_pcb; 219 /* Re-enable interrupts if they were enabled previously */ 220 if (td->td_md.md_spinlock_count == 0) { 221 if (__predict_true(tf->tf_spsr & PSR_I) == 0) 222 enable_interrupts(PSR_I); 223 if (__predict_true(tf->tf_spsr & PSR_F) == 0) 224 enable_interrupts(PSR_F); 225 } 226 227 228 /* Invoke the appropriate handler, if necessary */ 229 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 230 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 231 td, &ksig)) { 232 goto do_trapsignal; 233 } 234 goto out; 235 } 236 237 /* 238 * At this point, we're dealing with one of the following data aborts: 239 * 240 * FAULT_TRANS_S - Translation -- Section 241 * FAULT_TRANS_P - Translation -- Page 242 * FAULT_DOMAIN_S - Domain -- Section 243 * FAULT_DOMAIN_P - Domain -- Page 244 * FAULT_PERM_S - Permission -- Section 245 * FAULT_PERM_P - Permission -- Page 246 * 247 * These are the main virtual memory-related faults signalled by 248 * the MMU. 249 */ 250 251 /* 252 * Make sure the Program Counter is sane. We could fall foul of 253 * someone executing Thumb code, in which case the PC might not 254 * be word-aligned. This would cause a kernel alignment fault 255 * further down if we have to decode the current instruction. 256 * XXX: It would be nice to be able to support Thumb at some point. 257 */ 258 if (__predict_false((tf->tf_pc & 3) != 0)) { 259 if (user) { 260 /* 261 * Give the user an illegal instruction signal. 262 */ 263 /* Deliver a SIGILL to the process */ 264 ksig.signb = SIGILL; 265 ksig.code = 0; 266 goto do_trapsignal; 267 } 268 269 /* 270 * The kernel never executes Thumb code. 271 */ 272 printf("\ndata_abort_fault: Misaligned Kernel-mode " 273 "Program Counter\n"); 274 dab_fatal(tf, fsr, far, td, &ksig); 275 } 276 277 va = trunc_page((vm_offset_t)far); 278 279 /* 280 * It is only a kernel address space fault iff: 281 * 1. user == 0 and 282 * 2. pcb_onfault not set or 283 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 284 */ 285 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 286 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 287 __predict_true((pcb->pcb_onfault == NULL || 288 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 289 map = kernel_map; 290 291 /* Was the fault due to the FPE/IPKDB ? */ 292 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 293 294 /* 295 * Force exit via userret() 296 * This is necessary as the FPE is an extension to 297 * userland that actually runs in a priveledged mode 298 * but uses USR mode permissions for its accesses. 299 */ 300 user = 1; 301 ksig.signb = SIGSEGV; 302 ksig.code = 0; 303 goto do_trapsignal; 304 } 305 } else { 306 map = &td->td_proc->p_vmspace->vm_map; 307 } 308 309 /* 310 * We need to know whether the page should be mapped as R or R/W. 311 * On armv4, the fault status register does not indicate whether 312 * the access was a read or write. We know that a permission fault 313 * can only be the result of a write to a read-only location, so we 314 * can deal with those quickly. Otherwise we need to disassemble 315 * the faulting instruction to determine if it was a write. 316 */ 317 if (IS_PERMISSION_FAULT(fsr)) 318 ftype = VM_PROT_WRITE; 319 else { 320 u_int insn = ReadWord(tf->tf_pc); 321 322 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */ 323 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */ 324 ((insn & 0x0a100000) == 0x08000000)) { /* STM/CDT */ 325 ftype = VM_PROT_WRITE; 326 } else { 327 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */ 328 ftype = VM_PROT_READ | VM_PROT_WRITE; 329 else 330 ftype = VM_PROT_READ; 331 } 332 } 333 334 /* 335 * See if the fault is as a result of ref/mod emulation, 336 * or domain mismatch. 337 */ 338#ifdef DEBUG 339 last_fault_code = fsr; 340#endif 341 if (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, 342 NULL, "Kernel page fault") != 0) 343 goto fatal_pagefault; 344 345 if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype, 346 user)) { 347 goto out; 348 } 349 350 onfault = pcb->pcb_onfault; 351 pcb->pcb_onfault = NULL; 352 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 353 pcb->pcb_onfault = onfault; 354 if (__predict_true(error == 0)) 355 goto out; 356fatal_pagefault: 357 if (user == 0) { 358 if (pcb->pcb_onfault) { 359 tf->tf_r0 = error; 360 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 361 return; 362 } 363 364 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype, 365 error); 366 dab_fatal(tf, fsr, far, td, &ksig); 367 } 368 369 370 if (error == ENOMEM) { 371 printf("VM: pid %d (%s), uid %d killed: " 372 "out of swap\n", td->td_proc->p_pid, td->td_name, 373 (td->td_proc->p_ucred) ? 374 td->td_proc->p_ucred->cr_uid : -1); 375 ksig.signb = SIGKILL; 376 } else { 377 ksig.signb = SIGSEGV; 378 } 379 ksig.code = 0; 380do_trapsignal: 381 call_trapsignal(td, ksig.signb, ksig.code); 382out: 383 /* If returning to user mode, make sure to invoke userret() */ 384 if (user) 385 userret(td, tf); 386} 387 388/* 389 * dab_fatal() handles the following data aborts: 390 * 391 * FAULT_WRTBUF_0 - Vector Exception 392 * FAULT_WRTBUF_1 - Terminal Exception 393 * 394 * We should never see these on a properly functioning system. 395 * 396 * This function is also called by the other handlers if they 397 * detect a fatal problem. 398 * 399 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 400 */ 401static int 402dab_fatal(struct trapframe *tf, u_int fsr, u_int far, struct thread *td, 403 struct ksig *ksig) 404{ 405 const char *mode; 406 407#ifdef KDTRACE_HOOKS 408 if (!TRAP_USERMODE(tf)) { 409 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(tf, far & FAULT_TYPE_MASK)) 410 return (0); 411 } 412#endif 413 414 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 415 416 disable_interrupts(PSR_I|PSR_F); 417 if (td != NULL) { 418 printf("Fatal %s mode data abort: '%s'\n", mode, 419 data_aborts[fsr & FAULT_TYPE_MASK].desc); 420 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 421 if ((fsr & FAULT_IMPRECISE) == 0) 422 printf("%08x, ", far); 423 else 424 printf("Invalid, "); 425 printf("spsr=%08x\n", tf->tf_spsr); 426 } else { 427 printf("Fatal %s mode prefetch abort at 0x%08x\n", 428 mode, tf->tf_pc); 429 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 430 } 431 432 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 433 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 434 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 435 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 436 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 437 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 438 printf("r12=%08x, ", tf->tf_r12); 439 440 if (TRAP_USERMODE(tf)) 441 printf("usp=%08x, ulr=%08x", 442 tf->tf_usr_sp, tf->tf_usr_lr); 443 else 444 printf("ssp=%08x, slr=%08x", 445 tf->tf_svc_sp, tf->tf_svc_lr); 446 printf(", pc =%08x\n\n", tf->tf_pc); 447 448#ifdef KDB 449 if (debugger_on_panic || kdb_active) 450 if (kdb_trap(fsr, 0, tf)) 451 return (0); 452#endif 453 panic("Fatal abort"); 454 /*NOTREACHED*/ 455} 456 457/* 458 * dab_align() handles the following data aborts: 459 * 460 * FAULT_ALIGN_0 - Alignment fault 461 * FAULT_ALIGN_1 - Alignment fault 462 * 463 * These faults are fatal if they happen in kernel mode. Otherwise, we 464 * deliver a bus error to the process. 465 */ 466static int 467dab_align(struct trapframe *tf, u_int fsr, u_int far, struct thread *td, 468 struct ksig *ksig) 469{ 470 471 /* Alignment faults are always fatal if they occur in kernel mode */ 472 if (!TRAP_USERMODE(tf)) { 473 if (!td || !td->td_pcb->pcb_onfault) 474 dab_fatal(tf, fsr, far, td, ksig); 475 tf->tf_r0 = EFAULT; 476 tf->tf_pc = (int)td->td_pcb->pcb_onfault; 477 return (0); 478 } 479 480 /* pcb_onfault *must* be NULL at this point */ 481 482 /* Deliver a bus error signal to the process */ 483 ksig->code = 0; 484 ksig->signb = SIGBUS; 485 td->td_frame = tf; 486 487 return (1); 488} 489 490/* 491 * dab_buserr() handles the following data aborts: 492 * 493 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 494 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 495 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 496 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 497 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 498 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 499 * 500 * If pcb_onfault is set, flag the fault and return to the handler. 501 * If the fault occurred in user mode, give the process a SIGBUS. 502 * 503 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 504 * can be flagged as imprecise in the FSR. This causes a real headache 505 * since some of the machine state is lost. In this case, tf->tf_pc 506 * may not actually point to the offending instruction. In fact, if 507 * we've taken a double abort fault, it generally points somewhere near 508 * the top of "data_abort_entry" in exception.S. 509 * 510 * In all other cases, these data aborts are considered fatal. 511 */ 512static int 513dab_buserr(struct trapframe *tf, u_int fsr, u_int far, struct thread *td, 514 struct ksig *ksig) 515{ 516 struct pcb *pcb = td->td_pcb; 517 518#ifdef __XSCALE__ 519 if ((fsr & FAULT_IMPRECISE) != 0 && 520 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 521 /* 522 * Oops, an imprecise, double abort fault. We've lost the 523 * r14_abt/spsr_abt values corresponding to the original 524 * abort, and the spsr saved in the trapframe indicates 525 * ABT mode. 526 */ 527 tf->tf_spsr &= ~PSR_MODE; 528 529 /* 530 * We use a simple heuristic to determine if the double abort 531 * happened as a result of a kernel or user mode access. 532 * If the current trapframe is at the top of the kernel stack, 533 * the fault _must_ have come from user mode. 534 */ 535 if (tf != ((struct trapframe *)pcb->pcb_regs.sf_sp) - 1) { 536 /* 537 * Kernel mode. We're either about to die a 538 * spectacular death, or pcb_onfault will come 539 * to our rescue. Either way, the current value 540 * of tf->tf_pc is irrelevant. 541 */ 542 tf->tf_spsr |= PSR_SVC32_MODE; 543 if (pcb->pcb_onfault == NULL) 544 printf("\nKernel mode double abort!\n"); 545 } else { 546 /* 547 * User mode. We've lost the program counter at the 548 * time of the fault (not that it was accurate anyway; 549 * it's not called an imprecise fault for nothing). 550 * About all we can do is copy r14_usr to tf_pc and 551 * hope for the best. The process is about to get a 552 * SIGBUS, so it's probably history anyway. 553 */ 554 tf->tf_spsr |= PSR_USR32_MODE; 555 tf->tf_pc = tf->tf_usr_lr; 556 } 557 } 558 559 /* FAR is invalid for imprecise exceptions */ 560 if ((fsr & FAULT_IMPRECISE) != 0) 561 far = 0; 562#endif /* __XSCALE__ */ 563 564 if (pcb->pcb_onfault) { 565 tf->tf_r0 = EFAULT; 566 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 567 return (0); 568 } 569 570 /* 571 * At this point, if the fault happened in kernel mode, we're toast 572 */ 573 if (!TRAP_USERMODE(tf)) 574 dab_fatal(tf, fsr, far, td, ksig); 575 576 /* Deliver a bus error signal to the process */ 577 ksig->signb = SIGBUS; 578 ksig->code = 0; 579 td->td_frame = tf; 580 581 return (1); 582} 583 584/* 585 * void prefetch_abort_handler(struct trapframe *tf) 586 * 587 * Abort handler called when instruction execution occurs at 588 * a non existent or restricted (access permissions) memory page. 589 * If the address is invalid and we were in SVC mode then panic as 590 * the kernel should never prefetch abort. 591 * If the address is invalid and the page is mapped then the user process 592 * does no have read permission so send it a signal. 593 * Otherwise fault the page in and try again. 594 */ 595static void 596prefetch_abort_handler(struct trapframe *tf) 597{ 598 struct thread *td; 599 struct proc * p; 600 struct vm_map *map; 601 vm_offset_t fault_pc, va; 602 int error = 0; 603 struct ksig ksig; 604 605 606#if 0 607 /* Update vmmeter statistics */ 608 uvmexp.traps++; 609#endif 610#if 0 611 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, 612 (void*)tf->tf_usr_lr); 613#endif 614 615 td = curthread; 616 p = td->td_proc; 617 PCPU_INC(cnt.v_trap); 618 619 if (TRAP_USERMODE(tf)) { 620 td->td_frame = tf; 621 if (td->td_cowgen != td->td_proc->p_cowgen) 622 thread_cow_update(td); 623 } 624 fault_pc = tf->tf_pc; 625 if (td->td_md.md_spinlock_count == 0) { 626 if (__predict_true(tf->tf_spsr & PSR_I) == 0) 627 enable_interrupts(PSR_I); 628 if (__predict_true(tf->tf_spsr & PSR_F) == 0) 629 enable_interrupts(PSR_F); 630 } 631 632 /* Prefetch aborts cannot happen in kernel mode */ 633 if (__predict_false(!TRAP_USERMODE(tf))) 634 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); 635 td->td_pticks = 0; 636 637 638 /* Ok validate the address, can only execute in USER space */ 639 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 640 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 641 ksig.signb = SIGSEGV; 642 ksig.code = 0; 643 goto do_trapsignal; 644 } 645 646 map = &td->td_proc->p_vmspace->vm_map; 647 va = trunc_page(fault_pc); 648 649 /* 650 * See if the pmap can handle this fault on its own... 651 */ 652#ifdef DEBUG 653 last_fault_code = -1; 654#endif 655 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) 656 goto out; 657 658 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, 659 VM_FAULT_NORMAL); 660 if (__predict_true(error == 0)) 661 goto out; 662 663 if (error == ENOMEM) { 664 printf("VM: pid %d (%s), uid %d killed: " 665 "out of swap\n", td->td_proc->p_pid, td->td_name, 666 (td->td_proc->p_ucred) ? 667 td->td_proc->p_ucred->cr_uid : -1); 668 ksig.signb = SIGKILL; 669 } else { 670 ksig.signb = SIGSEGV; 671 } 672 ksig.code = 0; 673 674do_trapsignal: 675 call_trapsignal(td, ksig.signb, ksig.code); 676 677out: 678 userret(td, tf); 679 680} 681 682extern int badaddr_read_1(const uint8_t *, uint8_t *); 683extern int badaddr_read_2(const uint16_t *, uint16_t *); 684extern int badaddr_read_4(const uint32_t *, uint32_t *); 685/* 686 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 687 * If the read succeeds, the value is written to 'rptr' and zero is returned. 688 * Else, return EFAULT. 689 */ 690int 691badaddr_read(void *addr, size_t size, void *rptr) 692{ 693 union { 694 uint8_t v1; 695 uint16_t v2; 696 uint32_t v4; 697 } u; 698 int rv; 699 700 cpu_drain_writebuf(); 701 702 /* Read from the test address. */ 703 switch (size) { 704 case sizeof(uint8_t): 705 rv = badaddr_read_1(addr, &u.v1); 706 if (rv == 0 && rptr) 707 *(uint8_t *) rptr = u.v1; 708 break; 709 710 case sizeof(uint16_t): 711 rv = badaddr_read_2(addr, &u.v2); 712 if (rv == 0 && rptr) 713 *(uint16_t *) rptr = u.v2; 714 break; 715 716 case sizeof(uint32_t): 717 rv = badaddr_read_4(addr, &u.v4); 718 if (rv == 0 && rptr) 719 *(uint32_t *) rptr = u.v4; 720 break; 721 722 default: 723 panic("badaddr: invalid size (%lu)", (u_long) size); 724 } 725 726 /* Return EFAULT if the address was invalid, else zero */ 727 return (rv); 728} 729