trap-v4.c revision 245551
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 82#include "opt_ktrace.h" 83 84#include <sys/cdefs.h> 85__FBSDID("$FreeBSD: head/sys/arm/arm/trap.c 245551 2013-01-17 09:52:35Z andrew $"); 86 87#include <sys/param.h> 88#include <sys/systm.h> 89#include <sys/proc.h> 90#include <sys/kernel.h> 91#include <sys/lock.h> 92#include <sys/mutex.h> 93#include <sys/syscall.h> 94#include <sys/sysent.h> 95#include <sys/signalvar.h> 96#include <sys/ktr.h> 97#ifdef KTRACE 98#include <sys/uio.h> 99#include <sys/ktrace.h> 100#endif 101#include <sys/ptrace.h> 102#include <sys/pioctl.h> 103 104#include <vm/vm.h> 105#include <vm/pmap.h> 106#include <vm/vm_kern.h> 107#include <vm/vm_map.h> 108#include <vm/vm_extern.h> 109 110#include <machine/cpuconf.h> 111#include <machine/vmparam.h> 112#include <machine/frame.h> 113#include <machine/cpu.h> 114#include <machine/intr.h> 115#include <machine/pcb.h> 116#include <machine/proc.h> 117#include <machine/swi.h> 118 119#include <security/audit/audit.h> 120 121#ifdef KDB 122#include <sys/kdb.h> 123#endif 124 125 126void swi_handler(trapframe_t *); 127void undefinedinstruction(trapframe_t *); 128 129#include <machine/disassem.h> 130#include <machine/machdep.h> 131 132extern char fusubailout[]; 133 134#ifdef DEBUG 135int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 136#endif 137 138#if defined(CPU_ARM7TDMI) 139/* These CPUs may need data/prefetch abort fixups */ 140#define CPU_ABORT_FIXUP_REQUIRED 141#endif 142 143struct ksig { 144 int signb; 145 u_long code; 146}; 147struct data_abort { 148 int (*func)(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 149 const char *desc; 150}; 151 152static int dab_fatal(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 153static int dab_align(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 154static int dab_buserr(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 155 156static const struct data_abort data_aborts[] = { 157 {dab_fatal, "Vector Exception"}, 158 {dab_align, "Alignment Fault 1"}, 159 {dab_fatal, "Terminal Exception"}, 160 {dab_align, "Alignment Fault 3"}, 161 {dab_buserr, "External Linefetch Abort (S)"}, 162 {NULL, "Translation Fault (S)"}, 163 {dab_buserr, "External Linefetch Abort (P)"}, 164 {NULL, "Translation Fault (P)"}, 165 {dab_buserr, "External Non-Linefetch Abort (S)"}, 166 {NULL, "Domain Fault (S)"}, 167 {dab_buserr, "External Non-Linefetch Abort (P)"}, 168 {NULL, "Domain Fault (P)"}, 169 {dab_buserr, "External Translation Abort (L1)"}, 170 {NULL, "Permission Fault (S)"}, 171 {dab_buserr, "External Translation Abort (L2)"}, 172 {NULL, "Permission Fault (P)"} 173}; 174 175/* Determine if a fault came from user mode */ 176#define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE) 177 178/* Determine if 'x' is a permission fault */ 179#define IS_PERMISSION_FAULT(x) \ 180 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 181 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 182 183static __inline void 184call_trapsignal(struct thread *td, int sig, u_long code) 185{ 186 ksiginfo_t ksi; 187 188 ksiginfo_init_trap(&ksi); 189 ksi.ksi_signo = sig; 190 ksi.ksi_code = (int)code; 191 trapsignal(td, &ksi); 192} 193 194static __inline int 195data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 196{ 197#ifdef CPU_ABORT_FIXUP_REQUIRED 198 int error; 199 200 /* Call the cpu specific data abort fixup routine */ 201 error = cpu_dataabt_fixup(tf); 202 if (__predict_true(error != ABORT_FIXUP_FAILED)) 203 return (error); 204 205 /* 206 * Oops, couldn't fix up the instruction 207 */ 208 printf("data_abort_fixup: fixup for %s mode data abort failed.\n", 209 TRAP_USERMODE(tf) ? "user" : "kernel"); 210 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 211 *((u_int *)tf->tf_pc)); 212 disassemble(tf->tf_pc); 213 214 /* Die now if this happened in kernel mode */ 215 if (!TRAP_USERMODE(tf)) 216 dab_fatal(tf, fsr, far, td, NULL, ksig); 217 218 return (error); 219#else 220 return (ABORT_FIXUP_OK); 221#endif /* CPU_ABORT_FIXUP_REQUIRED */ 222} 223 224void 225data_abort_handler(trapframe_t *tf) 226{ 227 struct vm_map *map; 228 struct pcb *pcb; 229 struct thread *td; 230 u_int user, far, fsr; 231 vm_prot_t ftype; 232 void *onfault; 233 vm_offset_t va; 234 int error = 0; 235 struct ksig ksig; 236 struct proc *p; 237 238 239 /* Grab FAR/FSR before enabling interrupts */ 240 far = cpu_faultaddress(); 241 fsr = cpu_faultstatus(); 242#if 0 243 printf("data abort: %p (from %p %p)\n", (void*)far, (void*)tf->tf_pc, 244 (void*)tf->tf_svc_lr); 245#endif 246 247 /* Update vmmeter statistics */ 248#if 0 249 vmexp.traps++; 250#endif 251 252 td = curthread; 253 p = td->td_proc; 254 255 PCPU_INC(cnt.v_trap); 256 /* Data abort came from user mode? */ 257 user = TRAP_USERMODE(tf); 258 259 if (user) { 260 td->td_pticks = 0; 261 td->td_frame = tf; 262 if (td->td_ucred != td->td_proc->p_ucred) 263 cred_update_thread(td); 264 265 } 266 /* Grab the current pcb */ 267 pcb = td->td_pcb; 268 /* Re-enable interrupts if they were enabled previously */ 269 if (td->td_md.md_spinlock_count == 0) { 270 if (__predict_true(tf->tf_spsr & I32_bit) == 0) 271 enable_interrupts(I32_bit); 272 if (__predict_true(tf->tf_spsr & F32_bit) == 0) 273 enable_interrupts(F32_bit); 274 } 275 276 277 /* Invoke the appropriate handler, if necessary */ 278 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 279 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 280 td, &ksig)) { 281 goto do_trapsignal; 282 } 283 goto out; 284 } 285 286 /* 287 * At this point, we're dealing with one of the following data aborts: 288 * 289 * FAULT_TRANS_S - Translation -- Section 290 * FAULT_TRANS_P - Translation -- Page 291 * FAULT_DOMAIN_S - Domain -- Section 292 * FAULT_DOMAIN_P - Domain -- Page 293 * FAULT_PERM_S - Permission -- Section 294 * FAULT_PERM_P - Permission -- Page 295 * 296 * These are the main virtual memory-related faults signalled by 297 * the MMU. 298 */ 299 300 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 301 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 302 tf->tf_r0 = EFAULT; 303 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 304 return; 305 } 306 307 /* 308 * Make sure the Program Counter is sane. We could fall foul of 309 * someone executing Thumb code, in which case the PC might not 310 * be word-aligned. This would cause a kernel alignment fault 311 * further down if we have to decode the current instruction. 312 * XXX: It would be nice to be able to support Thumb at some point. 313 */ 314 if (__predict_false((tf->tf_pc & 3) != 0)) { 315 if (user) { 316 /* 317 * Give the user an illegal instruction signal. 318 */ 319 /* Deliver a SIGILL to the process */ 320 ksig.signb = SIGILL; 321 ksig.code = 0; 322 goto do_trapsignal; 323 } 324 325 /* 326 * The kernel never executes Thumb code. 327 */ 328 printf("\ndata_abort_fault: Misaligned Kernel-mode " 329 "Program Counter\n"); 330 dab_fatal(tf, fsr, far, td, &ksig); 331 } 332 333 /* See if the cpu state needs to be fixed up */ 334 switch (data_abort_fixup(tf, fsr, far, td, &ksig)) { 335 case ABORT_FIXUP_RETURN: 336 return; 337 case ABORT_FIXUP_FAILED: 338 /* Deliver a SIGILL to the process */ 339 ksig.signb = SIGILL; 340 ksig.code = 0; 341 goto do_trapsignal; 342 default: 343 break; 344 } 345 346 va = trunc_page((vm_offset_t)far); 347 348 /* 349 * It is only a kernel address space fault iff: 350 * 1. user == 0 and 351 * 2. pcb_onfault not set or 352 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 353 */ 354 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 355 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 356 __predict_true((pcb->pcb_onfault == NULL || 357 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 358 map = kernel_map; 359 360 /* Was the fault due to the FPE/IPKDB ? */ 361 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 362 363 /* 364 * Force exit via userret() 365 * This is necessary as the FPE is an extension to 366 * userland that actually runs in a priveledged mode 367 * but uses USR mode permissions for its accesses. 368 */ 369 user = 1; 370 ksig.signb = SIGSEGV; 371 ksig.code = 0; 372 goto do_trapsignal; 373 } 374 } else { 375 map = &td->td_proc->p_vmspace->vm_map; 376 } 377 378 /* 379 * We need to know whether the page should be mapped 380 * as R or R/W. The MMU does not give us the info as 381 * to whether the fault was caused by a read or a write. 382 * 383 * However, we know that a permission fault can only be 384 * the result of a write to a read-only location, so 385 * we can deal with those quickly. 386 * 387 * Otherwise we need to disassemble the instruction 388 * responsible to determine if it was a write. 389 */ 390 if (IS_PERMISSION_FAULT(fsr)) { 391 ftype = VM_PROT_WRITE; 392 } else { 393 u_int insn = ReadWord(tf->tf_pc); 394 395 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */ 396 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */ 397 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT */ 398 { 399 ftype = VM_PROT_WRITE; 400 } 401 else 402 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */ 403 ftype = VM_PROT_READ | VM_PROT_WRITE; 404 else 405 ftype = VM_PROT_READ; 406 } 407 408 /* 409 * See if the fault is as a result of ref/mod emulation, 410 * or domain mismatch. 411 */ 412#ifdef DEBUG 413 last_fault_code = fsr; 414#endif 415 if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype, 416 user)) { 417 goto out; 418 } 419 420 onfault = pcb->pcb_onfault; 421 pcb->pcb_onfault = NULL; 422 if (map != kernel_map) { 423 PROC_LOCK(p); 424 p->p_lock++; 425 PROC_UNLOCK(p); 426 } 427 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 428 pcb->pcb_onfault = onfault; 429 430 if (map != kernel_map) { 431 PROC_LOCK(p); 432 p->p_lock--; 433 PROC_UNLOCK(p); 434 } 435 if (__predict_true(error == 0)) 436 goto out; 437 if (user == 0) { 438 if (pcb->pcb_onfault) { 439 tf->tf_r0 = error; 440 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 441 return; 442 } 443 444 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype, 445 error); 446 dab_fatal(tf, fsr, far, td, &ksig); 447 } 448 449 450 if (error == ENOMEM) { 451 printf("VM: pid %d (%s), uid %d killed: " 452 "out of swap\n", td->td_proc->p_pid, td->td_name, 453 (td->td_proc->p_ucred) ? 454 td->td_proc->p_ucred->cr_uid : -1); 455 ksig.signb = SIGKILL; 456 } else { 457 ksig.signb = SIGSEGV; 458 } 459 ksig.code = 0; 460do_trapsignal: 461 call_trapsignal(td, ksig.signb, ksig.code); 462out: 463 /* If returning to user mode, make sure to invoke userret() */ 464 if (user) 465 userret(td, tf); 466} 467 468/* 469 * dab_fatal() handles the following data aborts: 470 * 471 * FAULT_WRTBUF_0 - Vector Exception 472 * FAULT_WRTBUF_1 - Terminal Exception 473 * 474 * We should never see these on a properly functioning system. 475 * 476 * This function is also called by the other handlers if they 477 * detect a fatal problem. 478 * 479 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 480 */ 481static int 482dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 483{ 484 const char *mode; 485 486 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 487 488 disable_interrupts(I32_bit|F32_bit); 489 if (td != NULL) { 490 printf("Fatal %s mode data abort: '%s'\n", mode, 491 data_aborts[fsr & FAULT_TYPE_MASK].desc); 492 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 493 if ((fsr & FAULT_IMPRECISE) == 0) 494 printf("%08x, ", far); 495 else 496 printf("Invalid, "); 497 printf("spsr=%08x\n", tf->tf_spsr); 498 } else { 499 printf("Fatal %s mode prefetch abort at 0x%08x\n", 500 mode, tf->tf_pc); 501 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 502 } 503 504 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 505 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 506 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 507 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 508 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 509 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 510 printf("r12=%08x, ", tf->tf_r12); 511 512 if (TRAP_USERMODE(tf)) 513 printf("usp=%08x, ulr=%08x", 514 tf->tf_usr_sp, tf->tf_usr_lr); 515 else 516 printf("ssp=%08x, slr=%08x", 517 tf->tf_svc_sp, tf->tf_svc_lr); 518 printf(", pc =%08x\n\n", tf->tf_pc); 519 520#ifdef KDB 521 if (debugger_on_panic || kdb_active) 522 kdb_trap(fsr, 0, tf); 523#endif 524 panic("Fatal abort"); 525 /*NOTREACHED*/ 526} 527 528/* 529 * dab_align() handles the following data aborts: 530 * 531 * FAULT_ALIGN_0 - Alignment fault 532 * FAULT_ALIGN_1 - Alignment fault 533 * 534 * These faults are fatal if they happen in kernel mode. Otherwise, we 535 * deliver a bus error to the process. 536 */ 537static int 538dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 539{ 540 541 /* Alignment faults are always fatal if they occur in kernel mode */ 542 if (!TRAP_USERMODE(tf)) { 543 if (!td || !td->td_pcb->pcb_onfault) 544 dab_fatal(tf, fsr, far, td, ksig); 545 tf->tf_r0 = EFAULT; 546 tf->tf_pc = (int)td->td_pcb->pcb_onfault; 547 return (0); 548 } 549 550 /* pcb_onfault *must* be NULL at this point */ 551 552 /* See if the cpu state needs to be fixed up */ 553 (void) data_abort_fixup(tf, fsr, far, td, ksig); 554 555 /* Deliver a bus error signal to the process */ 556 ksig->code = 0; 557 ksig->signb = SIGBUS; 558 td->td_frame = tf; 559 560 return (1); 561} 562 563/* 564 * dab_buserr() handles the following data aborts: 565 * 566 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 567 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 568 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 569 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 570 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 571 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 572 * 573 * If pcb_onfault is set, flag the fault and return to the handler. 574 * If the fault occurred in user mode, give the process a SIGBUS. 575 * 576 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 577 * can be flagged as imprecise in the FSR. This causes a real headache 578 * since some of the machine state is lost. In this case, tf->tf_pc 579 * may not actually point to the offending instruction. In fact, if 580 * we've taken a double abort fault, it generally points somewhere near 581 * the top of "data_abort_entry" in exception.S. 582 * 583 * In all other cases, these data aborts are considered fatal. 584 */ 585static int 586dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 587{ 588 struct pcb *pcb = td->td_pcb; 589 590#ifdef __XSCALE__ 591 if ((fsr & FAULT_IMPRECISE) != 0 && 592 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 593 /* 594 * Oops, an imprecise, double abort fault. We've lost the 595 * r14_abt/spsr_abt values corresponding to the original 596 * abort, and the spsr saved in the trapframe indicates 597 * ABT mode. 598 */ 599 tf->tf_spsr &= ~PSR_MODE; 600 601 /* 602 * We use a simple heuristic to determine if the double abort 603 * happened as a result of a kernel or user mode access. 604 * If the current trapframe is at the top of the kernel stack, 605 * the fault _must_ have come from user mode. 606 */ 607 if (tf != ((trapframe_t *)pcb->un_32.pcb32_sp) - 1) { 608 /* 609 * Kernel mode. We're either about to die a 610 * spectacular death, or pcb_onfault will come 611 * to our rescue. Either way, the current value 612 * of tf->tf_pc is irrelevant. 613 */ 614 tf->tf_spsr |= PSR_SVC32_MODE; 615 if (pcb->pcb_onfault == NULL) 616 printf("\nKernel mode double abort!\n"); 617 } else { 618 /* 619 * User mode. We've lost the program counter at the 620 * time of the fault (not that it was accurate anyway; 621 * it's not called an imprecise fault for nothing). 622 * About all we can do is copy r14_usr to tf_pc and 623 * hope for the best. The process is about to get a 624 * SIGBUS, so it's probably history anyway. 625 */ 626 tf->tf_spsr |= PSR_USR32_MODE; 627 tf->tf_pc = tf->tf_usr_lr; 628 } 629 } 630 631 /* FAR is invalid for imprecise exceptions */ 632 if ((fsr & FAULT_IMPRECISE) != 0) 633 far = 0; 634#endif /* __XSCALE__ */ 635 636 if (pcb->pcb_onfault) { 637 tf->tf_r0 = EFAULT; 638 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 639 return (0); 640 } 641 642 /* See if the cpu state needs to be fixed up */ 643 (void) data_abort_fixup(tf, fsr, far, td, ksig); 644 645 /* 646 * At this point, if the fault happened in kernel mode, we're toast 647 */ 648 if (!TRAP_USERMODE(tf)) 649 dab_fatal(tf, fsr, far, td, ksig); 650 651 /* Deliver a bus error signal to the process */ 652 ksig->signb = SIGBUS; 653 ksig->code = 0; 654 td->td_frame = tf; 655 656 return (1); 657} 658 659static __inline int 660prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig) 661{ 662#ifdef CPU_ABORT_FIXUP_REQUIRED 663 int error; 664 665 /* Call the cpu specific prefetch abort fixup routine */ 666 error = cpu_prefetchabt_fixup(tf); 667 if (__predict_true(error != ABORT_FIXUP_FAILED)) 668 return (error); 669 670 /* 671 * Oops, couldn't fix up the instruction 672 */ 673 printf( 674 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n", 675 TRAP_USERMODE(tf) ? "user" : "kernel"); 676 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 677 *((u_int *)tf->tf_pc)); 678 disassemble(tf->tf_pc); 679 680 /* Die now if this happened in kernel mode */ 681 if (!TRAP_USERMODE(tf)) 682 dab_fatal(tf, 0, tf->tf_pc, NULL, ksig); 683 684 return (error); 685#else 686 return (ABORT_FIXUP_OK); 687#endif /* CPU_ABORT_FIXUP_REQUIRED */ 688} 689 690/* 691 * void prefetch_abort_handler(trapframe_t *tf) 692 * 693 * Abort handler called when instruction execution occurs at 694 * a non existent or restricted (access permissions) memory page. 695 * If the address is invalid and we were in SVC mode then panic as 696 * the kernel should never prefetch abort. 697 * If the address is invalid and the page is mapped then the user process 698 * does no have read permission so send it a signal. 699 * Otherwise fault the page in and try again. 700 */ 701void 702prefetch_abort_handler(trapframe_t *tf) 703{ 704 struct thread *td; 705 struct proc * p; 706 struct vm_map *map; 707 vm_offset_t fault_pc, va; 708 int error = 0; 709 struct ksig ksig; 710 711 712#if 0 713 /* Update vmmeter statistics */ 714 uvmexp.traps++; 715#endif 716#if 0 717 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, 718 (void*)tf->tf_usr_lr); 719#endif 720 721 td = curthread; 722 p = td->td_proc; 723 PCPU_INC(cnt.v_trap); 724 725 if (TRAP_USERMODE(tf)) { 726 td->td_frame = tf; 727 if (td->td_ucred != td->td_proc->p_ucred) 728 cred_update_thread(td); 729 } 730 fault_pc = tf->tf_pc; 731 if (td->td_md.md_spinlock_count == 0) { 732 if (__predict_true(tf->tf_spsr & I32_bit) == 0) 733 enable_interrupts(I32_bit); 734 if (__predict_true(tf->tf_spsr & F32_bit) == 0) 735 enable_interrupts(F32_bit); 736 } 737 738 /* See if the cpu state needs to be fixed up */ 739 switch (prefetch_abort_fixup(tf, &ksig)) { 740 case ABORT_FIXUP_RETURN: 741 return; 742 case ABORT_FIXUP_FAILED: 743 /* Deliver a SIGILL to the process */ 744 ksig.signb = SIGILL; 745 ksig.code = 0; 746 td->td_frame = tf; 747 goto do_trapsignal; 748 default: 749 break; 750 } 751 752 /* Prefetch aborts cannot happen in kernel mode */ 753 if (__predict_false(!TRAP_USERMODE(tf))) 754 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); 755 td->td_pticks = 0; 756 757 758 /* Ok validate the address, can only execute in USER space */ 759 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 760 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 761 ksig.signb = SIGSEGV; 762 ksig.code = 0; 763 goto do_trapsignal; 764 } 765 766 map = &td->td_proc->p_vmspace->vm_map; 767 va = trunc_page(fault_pc); 768 769 /* 770 * See if the pmap can handle this fault on its own... 771 */ 772#ifdef DEBUG 773 last_fault_code = -1; 774#endif 775 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) 776 goto out; 777 778 if (map != kernel_map) { 779 PROC_LOCK(p); 780 p->p_lock++; 781 PROC_UNLOCK(p); 782 } 783 784 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, 785 VM_FAULT_NORMAL); 786 if (map != kernel_map) { 787 PROC_LOCK(p); 788 p->p_lock--; 789 PROC_UNLOCK(p); 790 } 791 792 if (__predict_true(error == 0)) 793 goto out; 794 795 if (error == ENOMEM) { 796 printf("VM: pid %d (%s), uid %d killed: " 797 "out of swap\n", td->td_proc->p_pid, td->td_name, 798 (td->td_proc->p_ucred) ? 799 td->td_proc->p_ucred->cr_uid : -1); 800 ksig.signb = SIGKILL; 801 } else { 802 ksig.signb = SIGSEGV; 803 } 804 ksig.code = 0; 805 806do_trapsignal: 807 call_trapsignal(td, ksig.signb, ksig.code); 808 809out: 810 userret(td, tf); 811 812} 813 814extern int badaddr_read_1(const uint8_t *, uint8_t *); 815extern int badaddr_read_2(const uint16_t *, uint16_t *); 816extern int badaddr_read_4(const uint32_t *, uint32_t *); 817/* 818 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 819 * If the read succeeds, the value is written to 'rptr' and zero is returned. 820 * Else, return EFAULT. 821 */ 822int 823badaddr_read(void *addr, size_t size, void *rptr) 824{ 825 union { 826 uint8_t v1; 827 uint16_t v2; 828 uint32_t v4; 829 } u; 830 int rv; 831 832 cpu_drain_writebuf(); 833 834 /* Read from the test address. */ 835 switch (size) { 836 case sizeof(uint8_t): 837 rv = badaddr_read_1(addr, &u.v1); 838 if (rv == 0 && rptr) 839 *(uint8_t *) rptr = u.v1; 840 break; 841 842 case sizeof(uint16_t): 843 rv = badaddr_read_2(addr, &u.v2); 844 if (rv == 0 && rptr) 845 *(uint16_t *) rptr = u.v2; 846 break; 847 848 case sizeof(uint32_t): 849 rv = badaddr_read_4(addr, &u.v4); 850 if (rv == 0 && rptr) 851 *(uint32_t *) rptr = u.v4; 852 break; 853 854 default: 855 panic("badaddr: invalid size (%lu)", (u_long) size); 856 } 857 858 /* Return EFAULT if the address was invalid, else zero */ 859 return (rv); 860} 861 862int 863cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa) 864{ 865 struct proc *p; 866 register_t *ap; 867 int error; 868 869#ifdef __ARM_EABI__ 870 sa->code = td->td_frame->tf_r7; 871#else 872 sa->code = sa->insn & 0x000fffff; 873#endif 874 ap = &td->td_frame->tf_r0; 875 if (sa->code == SYS_syscall) { 876 sa->code = *ap++; 877 sa->nap--; 878 } else if (sa->code == SYS___syscall) { 879 sa->code = ap[_QUAD_LOWWORD]; 880 sa->nap -= 2; 881 ap += 2; 882 } 883 p = td->td_proc; 884 if (p->p_sysent->sv_mask) 885 sa->code &= p->p_sysent->sv_mask; 886 if (sa->code >= p->p_sysent->sv_size) 887 sa->callp = &p->p_sysent->sv_table[0]; 888 else 889 sa->callp = &p->p_sysent->sv_table[sa->code]; 890 sa->narg = sa->callp->sy_narg; 891 error = 0; 892 memcpy(sa->args, ap, sa->nap * sizeof(register_t)); 893 if (sa->narg > sa->nap) { 894 error = copyin((void *)td->td_frame->tf_usr_sp, sa->args + 895 sa->nap, (sa->narg - sa->nap) * sizeof(register_t)); 896 } 897 if (error == 0) { 898 td->td_retval[0] = 0; 899 td->td_retval[1] = 0; 900 } 901 return (error); 902} 903 904#include "../../kern/subr_syscall.c" 905 906static void 907syscall(struct thread *td, trapframe_t *frame) 908{ 909 struct syscall_args sa; 910 int error; 911 912#ifndef __ARM_EABI__ 913 sa.insn = *(uint32_t *)(frame->tf_pc - INSN_SIZE); 914 switch (sa.insn & SWI_OS_MASK) { 915 case 0: /* XXX: we need our own one. */ 916 break; 917 default: 918 call_trapsignal(td, SIGILL, 0); 919 userret(td, frame); 920 return; 921 } 922#endif 923 sa.nap = 4; 924 925 error = syscallenter(td, &sa); 926 KASSERT(error != 0 || td->td_ar == NULL, 927 ("returning from syscall with td_ar set!")); 928 syscallret(td, error, &sa); 929} 930 931void 932swi_handler(trapframe_t *frame) 933{ 934 struct thread *td = curthread; 935 936 td->td_frame = frame; 937 938 td->td_pticks = 0; 939 /* 940 * Make sure the program counter is correctly aligned so we 941 * don't take an alignment fault trying to read the opcode. 942 */ 943 if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) { 944 call_trapsignal(td, SIGILL, 0); 945 userret(td, frame); 946 return; 947 } 948 /* 949 * Enable interrupts if they were enabled before the exception. 950 * Since all syscalls *should* come from user mode it will always 951 * be safe to enable them, but check anyway. 952 */ 953 if (td->td_md.md_spinlock_count == 0) { 954 if (__predict_true(frame->tf_spsr & I32_bit) == 0) 955 enable_interrupts(I32_bit); 956 if (__predict_true(frame->tf_spsr & F32_bit) == 0) 957 enable_interrupts(F32_bit); 958 } 959 960 syscall(td, frame); 961} 962 963