trap-v4.c revision 295887
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: head/sys/arm/arm/trap-v4.c 295887 2016-02-22 12:57:08Z skra $"); 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#if (ARM_MMU_V6 + ARM_MMU_V7) != 0 143 {NULL, "Translation Flag Fault"}, 144#else 145 {dab_buserr, "External Linefetch Abort (P)"}, 146#endif 147 {NULL, "Translation Fault (P)"}, 148 {dab_buserr, "External Non-Linefetch Abort (S)"}, 149 {NULL, "Domain Fault (S)"}, 150 {dab_buserr, "External Non-Linefetch Abort (P)"}, 151 {NULL, "Domain Fault (P)"}, 152 {dab_buserr, "External Translation Abort (L1)"}, 153 {NULL, "Permission Fault (S)"}, 154 {dab_buserr, "External Translation Abort (L2)"}, 155 {NULL, "Permission Fault (P)"} 156}; 157 158/* Determine if a fault came from user mode */ 159#define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE) 160 161/* Determine if 'x' is a permission fault */ 162#define IS_PERMISSION_FAULT(x) \ 163 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 164 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 165 166static __inline void 167call_trapsignal(struct thread *td, int sig, u_long code) 168{ 169 ksiginfo_t ksi; 170 171 ksiginfo_init_trap(&ksi); 172 ksi.ksi_signo = sig; 173 ksi.ksi_code = (int)code; 174 trapsignal(td, &ksi); 175} 176 177void 178abort_handler(struct trapframe *tf, int type) 179{ 180 struct vm_map *map; 181 struct pcb *pcb; 182 struct thread *td; 183 u_int user, far, fsr; 184 vm_prot_t ftype; 185 void *onfault; 186 vm_offset_t va; 187 int error = 0; 188 struct ksig ksig; 189 struct proc *p; 190 191 if (type == 1) 192 return (prefetch_abort_handler(tf)); 193 194 /* Grab FAR/FSR before enabling interrupts */ 195 far = cpu_faultaddress(); 196 fsr = cpu_faultstatus(); 197#if 0 198 printf("data abort: fault address=%p (from pc=%p lr=%p)\n", 199 (void*)far, (void*)tf->tf_pc, (void*)tf->tf_svc_lr); 200#endif 201 202 /* Update vmmeter statistics */ 203#if 0 204 vmexp.traps++; 205#endif 206 207 td = curthread; 208 p = td->td_proc; 209 210 PCPU_INC(cnt.v_trap); 211 /* Data abort came from user mode? */ 212 user = TRAP_USERMODE(tf); 213 214 if (user) { 215 td->td_pticks = 0; 216 td->td_frame = tf; 217 if (td->td_cowgen != td->td_proc->p_cowgen) 218 thread_cow_update(td); 219 220 } 221 /* Grab the current pcb */ 222 pcb = td->td_pcb; 223 /* Re-enable interrupts if they were enabled previously */ 224 if (td->td_md.md_spinlock_count == 0) { 225 if (__predict_true(tf->tf_spsr & PSR_I) == 0) 226 enable_interrupts(PSR_I); 227 if (__predict_true(tf->tf_spsr & PSR_F) == 0) 228 enable_interrupts(PSR_F); 229 } 230 231 232 /* Invoke the appropriate handler, if necessary */ 233 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 234 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 235 td, &ksig)) { 236 goto do_trapsignal; 237 } 238 goto out; 239 } 240 241 /* 242 * At this point, we're dealing with one of the following data aborts: 243 * 244 * FAULT_TRANS_S - Translation -- Section 245 * FAULT_TRANS_P - Translation -- Page 246 * FAULT_DOMAIN_S - Domain -- Section 247 * FAULT_DOMAIN_P - Domain -- Page 248 * FAULT_PERM_S - Permission -- Section 249 * FAULT_PERM_P - Permission -- Page 250 * 251 * These are the main virtual memory-related faults signalled by 252 * the MMU. 253 */ 254 255 /* 256 * Make sure the Program Counter is sane. We could fall foul of 257 * someone executing Thumb code, in which case the PC might not 258 * be word-aligned. This would cause a kernel alignment fault 259 * further down if we have to decode the current instruction. 260 * XXX: It would be nice to be able to support Thumb at some point. 261 */ 262 if (__predict_false((tf->tf_pc & 3) != 0)) { 263 if (user) { 264 /* 265 * Give the user an illegal instruction signal. 266 */ 267 /* Deliver a SIGILL to the process */ 268 ksig.signb = SIGILL; 269 ksig.code = 0; 270 goto do_trapsignal; 271 } 272 273 /* 274 * The kernel never executes Thumb code. 275 */ 276 printf("\ndata_abort_fault: Misaligned Kernel-mode " 277 "Program Counter\n"); 278 dab_fatal(tf, fsr, far, td, &ksig); 279 } 280 281 va = trunc_page((vm_offset_t)far); 282 283 /* 284 * It is only a kernel address space fault iff: 285 * 1. user == 0 and 286 * 2. pcb_onfault not set or 287 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 288 */ 289 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 290 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 291 __predict_true((pcb->pcb_onfault == NULL || 292 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 293 map = kernel_map; 294 295 /* Was the fault due to the FPE/IPKDB ? */ 296 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 297 298 /* 299 * Force exit via userret() 300 * This is necessary as the FPE is an extension to 301 * userland that actually runs in a priveledged mode 302 * but uses USR mode permissions for its accesses. 303 */ 304 user = 1; 305 ksig.signb = SIGSEGV; 306 ksig.code = 0; 307 goto do_trapsignal; 308 } 309 } else { 310 map = &td->td_proc->p_vmspace->vm_map; 311 } 312 313 /* 314 * We need to know whether the page should be mapped as R or R/W. 315 * On armv4, the fault status register does not indicate whether 316 * the access was a read or write. We know that a permission fault 317 * can only be the result of a write to a read-only location, so we 318 * can deal with those quickly. Otherwise we need to disassemble 319 * the faulting instruction to determine if it was a write. 320 */ 321 if (IS_PERMISSION_FAULT(fsr)) 322 ftype = VM_PROT_WRITE; 323 else { 324 u_int insn = ReadWord(tf->tf_pc); 325 326 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */ 327 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */ 328 ((insn & 0x0a100000) == 0x08000000)) { /* STM/CDT */ 329 ftype = VM_PROT_WRITE; 330 } else { 331 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */ 332 ftype = VM_PROT_READ | VM_PROT_WRITE; 333 else 334 ftype = VM_PROT_READ; 335 } 336 } 337 338 /* 339 * See if the fault is as a result of ref/mod emulation, 340 * or domain mismatch. 341 */ 342#ifdef DEBUG 343 last_fault_code = fsr; 344#endif 345 if (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, 346 NULL, "Kernel page fault") != 0) 347 goto fatal_pagefault; 348 349 if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype, 350 user)) { 351 goto out; 352 } 353 354 onfault = pcb->pcb_onfault; 355 pcb->pcb_onfault = NULL; 356 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 357 pcb->pcb_onfault = onfault; 358 if (__predict_true(error == 0)) 359 goto out; 360fatal_pagefault: 361 if (user == 0) { 362 if (pcb->pcb_onfault) { 363 tf->tf_r0 = error; 364 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 365 return; 366 } 367 368 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype, 369 error); 370 dab_fatal(tf, fsr, far, td, &ksig); 371 } 372 373 374 if (error == ENOMEM) { 375 printf("VM: pid %d (%s), uid %d killed: " 376 "out of swap\n", td->td_proc->p_pid, td->td_name, 377 (td->td_proc->p_ucred) ? 378 td->td_proc->p_ucred->cr_uid : -1); 379 ksig.signb = SIGKILL; 380 } else { 381 ksig.signb = SIGSEGV; 382 } 383 ksig.code = 0; 384do_trapsignal: 385 call_trapsignal(td, ksig.signb, ksig.code); 386out: 387 /* If returning to user mode, make sure to invoke userret() */ 388 if (user) 389 userret(td, tf); 390} 391 392/* 393 * dab_fatal() handles the following data aborts: 394 * 395 * FAULT_WRTBUF_0 - Vector Exception 396 * FAULT_WRTBUF_1 - Terminal Exception 397 * 398 * We should never see these on a properly functioning system. 399 * 400 * This function is also called by the other handlers if they 401 * detect a fatal problem. 402 * 403 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 404 */ 405static int 406dab_fatal(struct trapframe *tf, u_int fsr, u_int far, struct thread *td, 407 struct ksig *ksig) 408{ 409 const char *mode; 410 411#ifdef KDTRACE_HOOKS 412 if (!TRAP_USERMODE(tf)) { 413 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(tf, far & FAULT_TYPE_MASK)) 414 return (0); 415 } 416#endif 417 418 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 419 420 disable_interrupts(PSR_I|PSR_F); 421 if (td != NULL) { 422 printf("Fatal %s mode data abort: '%s'\n", mode, 423 data_aborts[fsr & FAULT_TYPE_MASK].desc); 424 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 425 if ((fsr & FAULT_IMPRECISE) == 0) 426 printf("%08x, ", far); 427 else 428 printf("Invalid, "); 429 printf("spsr=%08x\n", tf->tf_spsr); 430 } else { 431 printf("Fatal %s mode prefetch abort at 0x%08x\n", 432 mode, tf->tf_pc); 433 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 434 } 435 436 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 437 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 438 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 439 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 440 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 441 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 442 printf("r12=%08x, ", tf->tf_r12); 443 444 if (TRAP_USERMODE(tf)) 445 printf("usp=%08x, ulr=%08x", 446 tf->tf_usr_sp, tf->tf_usr_lr); 447 else 448 printf("ssp=%08x, slr=%08x", 449 tf->tf_svc_sp, tf->tf_svc_lr); 450 printf(", pc =%08x\n\n", tf->tf_pc); 451 452#ifdef KDB 453 if (debugger_on_panic || kdb_active) 454 if (kdb_trap(fsr, 0, tf)) 455 return (0); 456#endif 457 panic("Fatal abort"); 458 /*NOTREACHED*/ 459} 460 461/* 462 * dab_align() handles the following data aborts: 463 * 464 * FAULT_ALIGN_0 - Alignment fault 465 * FAULT_ALIGN_1 - Alignment fault 466 * 467 * These faults are fatal if they happen in kernel mode. Otherwise, we 468 * deliver a bus error to the process. 469 */ 470static int 471dab_align(struct trapframe *tf, u_int fsr, u_int far, struct thread *td, 472 struct ksig *ksig) 473{ 474 475 /* Alignment faults are always fatal if they occur in kernel mode */ 476 if (!TRAP_USERMODE(tf)) { 477 if (!td || !td->td_pcb->pcb_onfault) 478 dab_fatal(tf, fsr, far, td, ksig); 479 tf->tf_r0 = EFAULT; 480 tf->tf_pc = (int)td->td_pcb->pcb_onfault; 481 return (0); 482 } 483 484 /* pcb_onfault *must* be NULL at this point */ 485 486 /* Deliver a bus error signal to the process */ 487 ksig->code = 0; 488 ksig->signb = SIGBUS; 489 td->td_frame = tf; 490 491 return (1); 492} 493 494/* 495 * dab_buserr() handles the following data aborts: 496 * 497 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 498 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 499 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 500 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 501 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 502 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 503 * 504 * If pcb_onfault is set, flag the fault and return to the handler. 505 * If the fault occurred in user mode, give the process a SIGBUS. 506 * 507 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 508 * can be flagged as imprecise in the FSR. This causes a real headache 509 * since some of the machine state is lost. In this case, tf->tf_pc 510 * may not actually point to the offending instruction. In fact, if 511 * we've taken a double abort fault, it generally points somewhere near 512 * the top of "data_abort_entry" in exception.S. 513 * 514 * In all other cases, these data aborts are considered fatal. 515 */ 516static int 517dab_buserr(struct trapframe *tf, u_int fsr, u_int far, struct thread *td, 518 struct ksig *ksig) 519{ 520 struct pcb *pcb = td->td_pcb; 521 522#ifdef __XSCALE__ 523 if ((fsr & FAULT_IMPRECISE) != 0 && 524 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 525 /* 526 * Oops, an imprecise, double abort fault. We've lost the 527 * r14_abt/spsr_abt values corresponding to the original 528 * abort, and the spsr saved in the trapframe indicates 529 * ABT mode. 530 */ 531 tf->tf_spsr &= ~PSR_MODE; 532 533 /* 534 * We use a simple heuristic to determine if the double abort 535 * happened as a result of a kernel or user mode access. 536 * If the current trapframe is at the top of the kernel stack, 537 * the fault _must_ have come from user mode. 538 */ 539 if (tf != ((struct trapframe *)pcb->pcb_regs.sf_sp) - 1) { 540 /* 541 * Kernel mode. We're either about to die a 542 * spectacular death, or pcb_onfault will come 543 * to our rescue. Either way, the current value 544 * of tf->tf_pc is irrelevant. 545 */ 546 tf->tf_spsr |= PSR_SVC32_MODE; 547 if (pcb->pcb_onfault == NULL) 548 printf("\nKernel mode double abort!\n"); 549 } else { 550 /* 551 * User mode. We've lost the program counter at the 552 * time of the fault (not that it was accurate anyway; 553 * it's not called an imprecise fault for nothing). 554 * About all we can do is copy r14_usr to tf_pc and 555 * hope for the best. The process is about to get a 556 * SIGBUS, so it's probably history anyway. 557 */ 558 tf->tf_spsr |= PSR_USR32_MODE; 559 tf->tf_pc = tf->tf_usr_lr; 560 } 561 } 562 563 /* FAR is invalid for imprecise exceptions */ 564 if ((fsr & FAULT_IMPRECISE) != 0) 565 far = 0; 566#endif /* __XSCALE__ */ 567 568 if (pcb->pcb_onfault) { 569 tf->tf_r0 = EFAULT; 570 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 571 return (0); 572 } 573 574 /* 575 * At this point, if the fault happened in kernel mode, we're toast 576 */ 577 if (!TRAP_USERMODE(tf)) 578 dab_fatal(tf, fsr, far, td, ksig); 579 580 /* Deliver a bus error signal to the process */ 581 ksig->signb = SIGBUS; 582 ksig->code = 0; 583 td->td_frame = tf; 584 585 return (1); 586} 587 588/* 589 * void prefetch_abort_handler(struct trapframe *tf) 590 * 591 * Abort handler called when instruction execution occurs at 592 * a non existent or restricted (access permissions) memory page. 593 * If the address is invalid and we were in SVC mode then panic as 594 * the kernel should never prefetch abort. 595 * If the address is invalid and the page is mapped then the user process 596 * does no have read permission so send it a signal. 597 * Otherwise fault the page in and try again. 598 */ 599static void 600prefetch_abort_handler(struct trapframe *tf) 601{ 602 struct thread *td; 603 struct proc * p; 604 struct vm_map *map; 605 vm_offset_t fault_pc, va; 606 int error = 0; 607 struct ksig ksig; 608 609 610#if 0 611 /* Update vmmeter statistics */ 612 uvmexp.traps++; 613#endif 614#if 0 615 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, 616 (void*)tf->tf_usr_lr); 617#endif 618 619 td = curthread; 620 p = td->td_proc; 621 PCPU_INC(cnt.v_trap); 622 623 if (TRAP_USERMODE(tf)) { 624 td->td_frame = tf; 625 if (td->td_cowgen != td->td_proc->p_cowgen) 626 thread_cow_update(td); 627 } 628 fault_pc = tf->tf_pc; 629 if (td->td_md.md_spinlock_count == 0) { 630 if (__predict_true(tf->tf_spsr & PSR_I) == 0) 631 enable_interrupts(PSR_I); 632 if (__predict_true(tf->tf_spsr & PSR_F) == 0) 633 enable_interrupts(PSR_F); 634 } 635 636 /* Prefetch aborts cannot happen in kernel mode */ 637 if (__predict_false(!TRAP_USERMODE(tf))) 638 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); 639 td->td_pticks = 0; 640 641 642 /* Ok validate the address, can only execute in USER space */ 643 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 644 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 645 ksig.signb = SIGSEGV; 646 ksig.code = 0; 647 goto do_trapsignal; 648 } 649 650 map = &td->td_proc->p_vmspace->vm_map; 651 va = trunc_page(fault_pc); 652 653 /* 654 * See if the pmap can handle this fault on its own... 655 */ 656#ifdef DEBUG 657 last_fault_code = -1; 658#endif 659 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) 660 goto out; 661 662 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, 663 VM_FAULT_NORMAL); 664 if (__predict_true(error == 0)) 665 goto out; 666 667 if (error == ENOMEM) { 668 printf("VM: pid %d (%s), uid %d killed: " 669 "out of swap\n", td->td_proc->p_pid, td->td_name, 670 (td->td_proc->p_ucred) ? 671 td->td_proc->p_ucred->cr_uid : -1); 672 ksig.signb = SIGKILL; 673 } else { 674 ksig.signb = SIGSEGV; 675 } 676 ksig.code = 0; 677 678do_trapsignal: 679 call_trapsignal(td, ksig.signb, ksig.code); 680 681out: 682 userret(td, tf); 683 684} 685 686extern int badaddr_read_1(const uint8_t *, uint8_t *); 687extern int badaddr_read_2(const uint16_t *, uint16_t *); 688extern int badaddr_read_4(const uint32_t *, uint32_t *); 689/* 690 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 691 * If the read succeeds, the value is written to 'rptr' and zero is returned. 692 * Else, return EFAULT. 693 */ 694int 695badaddr_read(void *addr, size_t size, void *rptr) 696{ 697 union { 698 uint8_t v1; 699 uint16_t v2; 700 uint32_t v4; 701 } u; 702 int rv; 703 704 cpu_drain_writebuf(); 705 706 /* Read from the test address. */ 707 switch (size) { 708 case sizeof(uint8_t): 709 rv = badaddr_read_1(addr, &u.v1); 710 if (rv == 0 && rptr) 711 *(uint8_t *) rptr = u.v1; 712 break; 713 714 case sizeof(uint16_t): 715 rv = badaddr_read_2(addr, &u.v2); 716 if (rv == 0 && rptr) 717 *(uint16_t *) rptr = u.v2; 718 break; 719 720 case sizeof(uint32_t): 721 rv = badaddr_read_4(addr, &u.v4); 722 if (rv == 0 && rptr) 723 *(uint32_t *) rptr = u.v4; 724 break; 725 726 default: 727 panic("badaddr: invalid size (%lu)", (u_long) size); 728 } 729 730 /* Return EFAULT if the address was invalid, else zero */ 731 return (rv); 732} 733