1 /* $NetBSD: fault.c,v 1.100 2014/04/12 09:11:47 skrll Exp $ */ 2 3 /* 4 * Copyright 2003 Wasabi Systems, Inc. 5 * All rights reserved. 6 * 7 * Written by Steve C. Woodford for Wasabi Systems, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed for the NetBSD Project by 20 * Wasabi Systems, Inc. 21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 22 * or promote products derived from this software without specific prior 23 * written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 /* 38 * Copyright (c) 1994-1997 Mark Brinicombe. 39 * Copyright (c) 1994 Brini. 40 * All rights reserved. 41 * 42 * This code is derived from software written for Brini by Mark Brinicombe 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. All advertising materials mentioning features or use of this software 53 * must display the following acknowledgement: 54 * This product includes software developed by Brini. 55 * 4. The name of the company nor the name of the author may be used to 56 * endorse or promote products derived from this software without specific 57 * prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED 60 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 61 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 62 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 63 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 64 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 65 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * RiscBSD kernel project 72 * 73 * fault.c 74 * 75 * Fault handlers 76 * 77 * Created : 28/11/94 78 */ 79 80 #include "opt_ddb.h" 81 #include "opt_kgdb.h" 82 83 #include <sys/types.h> 84 __KERNEL_RCSID(0, "$NetBSD: fault.c,v 1.100 2014/04/12 09:11:47 skrll Exp $"); 85 86 #include <sys/param.h> 87 #include <sys/systm.h> 88 #include <sys/proc.h> 89 #include <sys/kernel.h> 90 #include <sys/kauth.h> 91 #include <sys/cpu.h> 92 #include <sys/intr.h> 93 94 #include <uvm/uvm_extern.h> 95 #include <uvm/uvm_stat.h> 96 #ifdef UVMHIST 97 #include <uvm/uvm.h> 98 #endif 99 100 #include <arm/locore.h> 101 102 #include <arm/arm32/katelib.h> 103 104 #include <machine/pcb.h> 105 #if defined(DDB) || defined(KGDB) 106 #include <machine/db_machdep.h> 107 #ifdef KGDB 108 #include <sys/kgdb.h> 109 #endif 110 #if !defined(DDB) 111 #define kdb_trap kgdb_trap 112 #endif 113 #endif 114 115 #include <arch/arm/arm/disassem.h> 116 #include <arm/arm32/machdep.h> 117 118 extern char fusubailout[]; 119 120 #ifdef DEBUG 121 int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 122 #endif 123 124 #if defined(CPU_ARM3) || defined(CPU_ARM6) || \ 125 defined(CPU_ARM7) || defined(CPU_ARM7TDMI) 126 /* These CPUs may need data/prefetch abort fixups */ 127 #define CPU_ABORT_FIXUP_REQUIRED 128 #endif 129 130 struct data_abort { 131 int (*func)(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 132 const char *desc; 133 }; 134 135 static int dab_fatal(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 136 static int dab_align(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 137 static int dab_buserr(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 138 139 static const struct data_abort data_aborts[] = { 140 {dab_fatal, "Vector Exception"}, 141 {dab_align, "Alignment Fault 1"}, 142 {dab_fatal, "Terminal Exception"}, 143 {dab_align, "Alignment Fault 3"}, 144 {dab_buserr, "External Linefetch Abort (S)"}, 145 {NULL, "Translation Fault (S)"}, 146 {dab_buserr, "External Linefetch Abort (P)"}, 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 'x' is a permission fault */ 159 #define IS_PERMISSION_FAULT(x) \ 160 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 161 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 162 163 #if 0 164 /* maybe one day we'll do emulations */ 165 #define TRAPSIGNAL(l,k) (*(l)->l_proc->p_emul->e_trapsignal)((l), (k)) 166 #else 167 #define TRAPSIGNAL(l,k) trapsignal((l), (k)) 168 #endif 169 170 static inline void 171 call_trapsignal(struct lwp *l, const struct trapframe *tf, ksiginfo_t *ksi) 172 { 173 if (l->l_proc->p_pid == 1 || cpu_printfataltraps) { 174 printf("%d.%d(%s): trap: signo=%d code=%d addr=%p trap=%#x\n", 175 l->l_proc->p_pid, l->l_lid, l->l_proc->p_comm, 176 ksi->ksi_signo, ksi->ksi_code, ksi->ksi_addr, 177 ksi->ksi_trap); 178 printf("r0=%08x r1=%08x r2=%08x r3=%08x\n", 179 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 180 printf("r4=%08x r5=%08x r6=%08x r7=%08x\n", 181 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 182 printf("r8=%08x r9=%08x rA=%08x rB=%08x\n", 183 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 184 printf("ip=%08x sp=%08x lr=%08x pc=%08x spsr=%08x\n", 185 tf->tf_r12, tf->tf_usr_sp, tf->tf_usr_lr, tf->tf_pc, 186 tf->tf_spsr); 187 } 188 189 TRAPSIGNAL(l, ksi); 190 } 191 192 static inline int 193 data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l) 194 { 195 #ifdef CPU_ABORT_FIXUP_REQUIRED 196 int error; 197 198 /* Call the CPU specific data abort fixup routine */ 199 error = cpu_dataabt_fixup(tf); 200 if (__predict_true(error != ABORT_FIXUP_FAILED)) 201 return (error); 202 203 /* 204 * Oops, couldn't fix up the instruction 205 */ 206 printf("%s: fixup for %s mode data abort failed.\n", __func__, 207 TRAP_USERMODE(tf) ? "user" : "kernel"); 208 #ifdef THUMB_CODE 209 if (tf->tf_spsr & PSR_T_bit) { 210 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 211 tf->tf_pc, *((uint16 *)(tf->tf_pc & ~1)), 212 *((uint16 *)((tf->tf_pc + 2) & ~1))); 213 } 214 else 215 #endif 216 { 217 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 218 *((u_int *)tf->tf_pc)); 219 } 220 disassemble(tf->tf_pc); 221 222 /* Die now if this happened in kernel mode */ 223 if (!TRAP_USERMODE(tf)) 224 dab_fatal(tf, fsr, far, l, NULL); 225 226 return (error); 227 #else 228 return (ABORT_FIXUP_OK); 229 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 230 } 231 232 void 233 data_abort_handler(trapframe_t *tf) 234 { 235 struct vm_map *map; 236 struct lwp * const l = curlwp; 237 struct cpu_info * const ci = curcpu(); 238 u_int far, fsr; 239 vm_prot_t ftype; 240 void *onfault; 241 vaddr_t va; 242 int error; 243 ksiginfo_t ksi; 244 245 UVMHIST_FUNC(__func__); 246 UVMHIST_CALLED(maphist); 247 248 /* Grab FAR/FSR before enabling interrupts */ 249 far = cpu_faultaddress(); 250 fsr = cpu_faultstatus(); 251 252 /* Update vmmeter statistics */ 253 ci->ci_data.cpu_ntrap++; 254 255 /* Re-enable interrupts if they were enabled previously */ 256 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 257 if (__predict_true((tf->tf_spsr & IF32_bits) != IF32_bits)) 258 restore_interrupts(tf->tf_spsr & IF32_bits); 259 260 /* Get the current lwp structure */ 261 262 UVMHIST_LOG(maphist, " (l=%#x, far=%#x, fsr=%#x", 263 l, far, fsr, 0); 264 UVMHIST_LOG(maphist, " tf=%#x, pc=%#x)", 265 tf, tf->tf_pc, 0, 0); 266 267 /* Data abort came from user mode? */ 268 bool user = (TRAP_USERMODE(tf) != 0); 269 if (user) 270 LWP_CACHE_CREDS(l, l->l_proc); 271 272 /* Grab the current pcb */ 273 struct pcb * const pcb = lwp_getpcb(l); 274 275 curcpu()->ci_abt_evs[fsr & FAULT_TYPE_MASK].ev_count++; 276 277 /* Invoke the appropriate handler, if necessary */ 278 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 279 #ifdef DIAGNOSTIC 280 printf("%s: data_aborts fsr=0x%x far=0x%x\n", 281 __func__, fsr, far); 282 #endif 283 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 284 l, &ksi)) 285 goto do_trapsignal; 286 goto out; 287 } 288 289 /* 290 * At this point, we're dealing with one of the following data aborts: 291 * 292 * FAULT_TRANS_S - Translation -- Section 293 * FAULT_TRANS_P - Translation -- Page 294 * FAULT_DOMAIN_S - Domain -- Section 295 * FAULT_DOMAIN_P - Domain -- Page 296 * FAULT_PERM_S - Permission -- Section 297 * FAULT_PERM_P - Permission -- Page 298 * 299 * These are the main virtual memory-related faults signalled by 300 * the MMU. 301 */ 302 303 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 304 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 305 tf->tf_r0 = EFAULT; 306 tf->tf_pc = (intptr_t) pcb->pcb_onfault; 307 return; 308 } 309 310 if (user) { 311 lwp_settrapframe(l, tf); 312 } 313 314 /* 315 * Make sure the Program Counter is sane. We could fall foul of 316 * someone executing Thumb code, in which case the PC might not 317 * be word-aligned. This would cause a kernel alignment fault 318 * further down if we have to decode the current instruction. 319 */ 320 #ifdef THUMB_CODE 321 /* 322 * XXX: It would be nice to be able to support Thumb in the kernel 323 * at some point. 324 */ 325 if (__predict_false(!user && (tf->tf_pc & 3) != 0)) { 326 printf("\n%s: Misaligned Kernel-mode Program Counter\n", 327 __func__); 328 dab_fatal(tf, fsr, far, l, NULL); 329 } 330 #else 331 if (__predict_false((tf->tf_pc & 3) != 0)) { 332 if (user) { 333 /* 334 * Give the user an illegal instruction signal. 335 */ 336 /* Deliver a SIGILL to the process */ 337 KSI_INIT_TRAP(&ksi); 338 ksi.ksi_signo = SIGILL; 339 ksi.ksi_code = ILL_ILLOPC; 340 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 341 ksi.ksi_trap = fsr; 342 goto do_trapsignal; 343 } 344 345 /* 346 * The kernel never executes Thumb code. 347 */ 348 printf("\n%s: Misaligned Kernel-mode Program Counter\n", 349 __func__); 350 dab_fatal(tf, fsr, far, l, NULL); 351 } 352 #endif 353 354 /* See if the CPU state needs to be fixed up */ 355 switch (data_abort_fixup(tf, fsr, far, l)) { 356 case ABORT_FIXUP_RETURN: 357 return; 358 case ABORT_FIXUP_FAILED: 359 /* Deliver a SIGILL to the process */ 360 KSI_INIT_TRAP(&ksi); 361 ksi.ksi_signo = SIGILL; 362 ksi.ksi_code = ILL_ILLOPC; 363 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 364 ksi.ksi_trap = fsr; 365 goto do_trapsignal; 366 default: 367 break; 368 } 369 370 va = trunc_page((vaddr_t)far); 371 372 /* 373 * It is only a kernel address space fault iff: 374 * 1. user == 0 and 375 * 2. pcb_onfault not set or 376 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 377 */ 378 if (!user && (va >= VM_MIN_KERNEL_ADDRESS || 379 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 380 __predict_true((pcb->pcb_onfault == NULL || 381 (read_insn(tf->tf_pc, false) & 0x05200000) != 0x04200000))) { 382 map = kernel_map; 383 384 /* Was the fault due to the FPE/IPKDB ? */ 385 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 386 KSI_INIT_TRAP(&ksi); 387 ksi.ksi_signo = SIGSEGV; 388 ksi.ksi_code = SEGV_ACCERR; 389 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 390 ksi.ksi_trap = fsr; 391 392 /* 393 * Force exit via userret() 394 * This is necessary as the FPE is an extension to 395 * userland that actually runs in a priveledged mode 396 * but uses USR mode permissions for its accesses. 397 */ 398 user = true; 399 goto do_trapsignal; 400 } 401 } else { 402 map = &l->l_proc->p_vmspace->vm_map; 403 } 404 405 /* 406 * We need to know whether the page should be mapped as R or R/W. 407 * Before ARMv6, the MMU did not give us the info as to whether the 408 * fault was caused by a read or a write. 409 * 410 * However, we know that a permission fault can only be the result of 411 * a write to a read-only location, so we can deal with those quickly. 412 * 413 * Otherwise we need to disassemble the instruction responsible to 414 * determine if it was a write. 415 */ 416 if (CPU_IS_ARMV6_P() || CPU_IS_ARMV7_P()) { 417 ftype = (fsr & FAULT_WRITE) ? VM_PROT_WRITE : VM_PROT_READ; 418 } else if (IS_PERMISSION_FAULT(fsr)) { 419 ftype = VM_PROT_WRITE; 420 } else { 421 #ifdef THUMB_CODE 422 /* Fast track the ARM case. */ 423 if (__predict_false(tf->tf_spsr & PSR_T_bit)) { 424 u_int insn = read_thumb_insn(tf->tf_pc, user); 425 u_int insn_f8 = insn & 0xf800; 426 u_int insn_fe = insn & 0xfe00; 427 428 if (insn_f8 == 0x6000 || /* STR(1) */ 429 insn_f8 == 0x7000 || /* STRB(1) */ 430 insn_f8 == 0x8000 || /* STRH(1) */ 431 insn_f8 == 0x9000 || /* STR(3) */ 432 insn_f8 == 0xc000 || /* STM */ 433 insn_fe == 0x5000 || /* STR(2) */ 434 insn_fe == 0x5200 || /* STRH(2) */ 435 insn_fe == 0x5400) /* STRB(2) */ 436 ftype = VM_PROT_WRITE; 437 else 438 ftype = VM_PROT_READ; 439 } 440 else 441 #endif 442 { 443 u_int insn = read_insn(tf->tf_pc, user); 444 445 if (((insn & 0x0c100000) == 0x04000000) || /* STR[B] */ 446 ((insn & 0x0e1000b0) == 0x000000b0) || /* STR[HD]*/ 447 ((insn & 0x0a100000) == 0x08000000) || /* STM/CDT*/ 448 ((insn & 0x0f9000f0) == 0x01800090)) /* STREX[BDH] */ 449 ftype = VM_PROT_WRITE; 450 else if ((insn & 0x0fb00ff0) == 0x01000090)/* SWP */ 451 ftype = VM_PROT_READ | VM_PROT_WRITE; 452 else 453 ftype = VM_PROT_READ; 454 } 455 } 456 457 /* 458 * See if the fault is as a result of ref/mod emulation, 459 * or domain mismatch. 460 */ 461 #ifdef DEBUG 462 last_fault_code = fsr; 463 #endif 464 if (pmap_fault_fixup(map->pmap, va, ftype, user)) { 465 UVMHIST_LOG(maphist, " <- ref/mod emul", 0, 0, 0, 0); 466 goto out; 467 } 468 469 if (__predict_false(curcpu()->ci_intr_depth > 0)) { 470 if (pcb->pcb_onfault) { 471 tf->tf_r0 = EINVAL; 472 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 473 return; 474 } 475 printf("\nNon-emulated page fault with intr_depth > 0\n"); 476 dab_fatal(tf, fsr, far, l, NULL); 477 } 478 479 onfault = pcb->pcb_onfault; 480 pcb->pcb_onfault = NULL; 481 error = uvm_fault(map, va, ftype); 482 pcb->pcb_onfault = onfault; 483 484 if (__predict_true(error == 0)) { 485 if (user) 486 uvm_grow(l->l_proc, va); /* Record any stack growth */ 487 else 488 ucas_ras_check(tf); 489 UVMHIST_LOG(maphist, " <- uvm", 0, 0, 0, 0); 490 goto out; 491 } 492 493 if (user == 0) { 494 if (pcb->pcb_onfault) { 495 tf->tf_r0 = error; 496 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 497 return; 498 } 499 500 printf("\nuvm_fault(%p, %lx, %x) -> %x\n", map, va, ftype, 501 error); 502 dab_fatal(tf, fsr, far, l, NULL); 503 } 504 505 KSI_INIT_TRAP(&ksi); 506 507 if (error == ENOMEM) { 508 printf("UVM: pid %d (%s), uid %d killed: " 509 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 510 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 511 ksi.ksi_signo = SIGKILL; 512 } else 513 ksi.ksi_signo = SIGSEGV; 514 515 ksi.ksi_code = (error == EACCES) ? SEGV_ACCERR : SEGV_MAPERR; 516 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 517 ksi.ksi_trap = fsr; 518 UVMHIST_LOG(maphist, " <- error (%d)", error, 0, 0, 0); 519 520 do_trapsignal: 521 call_trapsignal(l, tf, &ksi); 522 out: 523 /* If returning to user mode, make sure to invoke userret() */ 524 if (user) 525 userret(l); 526 } 527 528 /* 529 * dab_fatal() handles the following data aborts: 530 * 531 * FAULT_WRTBUF_0 - Vector Exception 532 * FAULT_WRTBUF_1 - Terminal Exception 533 * 534 * We should never see these on a properly functioning system. 535 * 536 * This function is also called by the other handlers if they 537 * detect a fatal problem. 538 * 539 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 540 */ 541 static int 542 dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 543 { 544 const char * const mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 545 546 if (l != NULL) { 547 printf("Fatal %s mode data abort: '%s'\n", mode, 548 data_aborts[fsr & FAULT_TYPE_MASK].desc); 549 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 550 if ((fsr & FAULT_IMPRECISE) == 0) 551 printf("%08x, ", far); 552 else 553 printf("Invalid, "); 554 printf("spsr=%08x\n", tf->tf_spsr); 555 } else { 556 printf("Fatal %s mode prefetch abort at 0x%08x\n", 557 mode, tf->tf_pc); 558 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 559 } 560 561 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 562 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 563 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 564 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 565 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 566 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 567 printf("r12=%08x, ", tf->tf_r12); 568 569 if (TRAP_USERMODE(tf)) 570 printf("usp=%08x, ulr=%08x", 571 tf->tf_usr_sp, tf->tf_usr_lr); 572 else 573 printf("ssp=%08x, slr=%08x", 574 tf->tf_svc_sp, tf->tf_svc_lr); 575 printf(", pc =%08x\n\n", tf->tf_pc); 576 577 #if defined(DDB) || defined(KGDB) 578 kdb_trap(T_FAULT, tf); 579 #endif 580 panic("Fatal abort"); 581 /*NOTREACHED*/ 582 } 583 584 /* 585 * dab_align() handles the following data aborts: 586 * 587 * FAULT_ALIGN_0 - Alignment fault 588 * FAULT_ALIGN_0 - Alignment fault 589 * 590 * These faults are fatal if they happen in kernel mode. Otherwise, we 591 * deliver a bus error to the process. 592 */ 593 static int 594 dab_align(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 595 { 596 /* Alignment faults are always fatal if they occur in kernel mode */ 597 if (!TRAP_USERMODE(tf)) 598 dab_fatal(tf, fsr, far, l, NULL); 599 600 /* pcb_onfault *must* be NULL at this point */ 601 KDASSERT(((struct pcb *)lwp_getpcb(l))->pcb_onfault == NULL); 602 603 /* See if the CPU state needs to be fixed up */ 604 (void) data_abort_fixup(tf, fsr, far, l); 605 606 /* Deliver a bus error signal to the process */ 607 KSI_INIT_TRAP(ksi); 608 ksi->ksi_signo = SIGBUS; 609 ksi->ksi_code = BUS_ADRALN; 610 ksi->ksi_addr = (uint32_t *)(intptr_t)far; 611 ksi->ksi_trap = fsr; 612 613 lwp_settrapframe(l, tf); 614 615 return (1); 616 } 617 618 /* 619 * dab_buserr() handles the following data aborts: 620 * 621 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 622 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 623 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 624 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 625 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 626 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 627 * 628 * If pcb_onfault is set, flag the fault and return to the handler. 629 * If the fault occurred in user mode, give the process a SIGBUS. 630 * 631 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 632 * can be flagged as imprecise in the FSR. This causes a real headache 633 * since some of the machine state is lost. In this case, tf->tf_pc 634 * may not actually point to the offending instruction. In fact, if 635 * we've taken a double abort fault, it generally points somewhere near 636 * the top of "data_abort_entry" in exception.S. 637 * 638 * In all other cases, these data aborts are considered fatal. 639 */ 640 static int 641 dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, 642 ksiginfo_t *ksi) 643 { 644 struct pcb *pcb = lwp_getpcb(l); 645 646 #ifdef __XSCALE__ 647 if ((fsr & FAULT_IMPRECISE) != 0 && 648 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 649 /* 650 * Oops, an imprecise, double abort fault. We've lost the 651 * r14_abt/spsr_abt values corresponding to the original 652 * abort, and the spsr saved in the trapframe indicates 653 * ABT mode. 654 */ 655 tf->tf_spsr &= ~PSR_MODE; 656 657 /* 658 * We use a simple heuristic to determine if the double abort 659 * happened as a result of a kernel or user mode access. 660 * If the current trapframe is at the top of the kernel stack, 661 * the fault _must_ have come from user mode. 662 */ 663 if (tf != ((trapframe_t *)pcb->pcb_ksp) - 1) { 664 /* 665 * Kernel mode. We're either about to die a 666 * spectacular death, or pcb_onfault will come 667 * to our rescue. Either way, the current value 668 * of tf->tf_pc is irrelevant. 669 */ 670 tf->tf_spsr |= PSR_SVC32_MODE; 671 if (pcb->pcb_onfault == NULL) 672 printf("\nKernel mode double abort!\n"); 673 } else { 674 /* 675 * User mode. We've lost the program counter at the 676 * time of the fault (not that it was accurate anyway; 677 * it's not called an imprecise fault for nothing). 678 * About all we can do is copy r14_usr to tf_pc and 679 * hope for the best. The process is about to get a 680 * SIGBUS, so it's probably history anyway. 681 */ 682 tf->tf_spsr |= PSR_USR32_MODE; 683 tf->tf_pc = tf->tf_usr_lr; 684 #ifdef THUMB_CODE 685 tf->tf_spsr &= ~PSR_T_bit; 686 if (tf->tf_usr_lr & 1) 687 tf->tf_spsr |= PSR_T_bit; 688 #endif 689 } 690 } 691 692 /* FAR is invalid for imprecise exceptions */ 693 if ((fsr & FAULT_IMPRECISE) != 0) 694 far = 0; 695 #endif /* __XSCALE__ */ 696 697 if (pcb->pcb_onfault) { 698 KDASSERT(TRAP_USERMODE(tf) == 0); 699 tf->tf_r0 = EFAULT; 700 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 701 return (0); 702 } 703 704 /* See if the CPU state needs to be fixed up */ 705 (void) data_abort_fixup(tf, fsr, far, l); 706 707 /* 708 * At this point, if the fault happened in kernel mode, we're toast 709 */ 710 if (!TRAP_USERMODE(tf)) 711 dab_fatal(tf, fsr, far, l, NULL); 712 713 /* Deliver a bus error signal to the process */ 714 KSI_INIT_TRAP(ksi); 715 ksi->ksi_signo = SIGBUS; 716 ksi->ksi_code = BUS_ADRERR; 717 ksi->ksi_addr = (uint32_t *)(intptr_t)far; 718 ksi->ksi_trap = fsr; 719 720 lwp_settrapframe(l, tf); 721 722 return (1); 723 } 724 725 static inline int 726 prefetch_abort_fixup(trapframe_t *tf) 727 { 728 #ifdef CPU_ABORT_FIXUP_REQUIRED 729 int error; 730 731 /* Call the CPU specific prefetch abort fixup routine */ 732 error = cpu_prefetchabt_fixup(tf); 733 if (__predict_true(error != ABORT_FIXUP_FAILED)) 734 return (error); 735 736 /* 737 * Oops, couldn't fix up the instruction 738 */ 739 printf("%s: fixup for %s mode prefetch abort failed.\n", __func__, 740 TRAP_USERMODE(tf) ? "user" : "kernel"); 741 #ifdef THUMB_CODE 742 if (tf->tf_spsr & PSR_T_bit) { 743 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 744 tf->tf_pc, *((uint16 *)(tf->tf_pc & ~1)), 745 *((uint16 *)((tf->tf_pc + 2) & ~1))); 746 } 747 else 748 #endif 749 { 750 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 751 *((u_int *)tf->tf_pc)); 752 } 753 disassemble(tf->tf_pc); 754 755 /* Die now if this happened in kernel mode */ 756 if (!TRAP_USERMODE(tf)) 757 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 758 759 return (error); 760 #else 761 return (ABORT_FIXUP_OK); 762 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 763 } 764 765 /* 766 * void prefetch_abort_handler(trapframe_t *tf) 767 * 768 * Abort handler called when instruction execution occurs at 769 * a non existent or restricted (access permissions) memory page. 770 * If the address is invalid and we were in SVC mode then panic as 771 * the kernel should never prefetch abort. 772 * If the address is invalid and the page is mapped then the user process 773 * does no have read permission so send it a signal. 774 * Otherwise fault the page in and try again. 775 */ 776 void 777 prefetch_abort_handler(trapframe_t *tf) 778 { 779 struct lwp *l; 780 struct pcb *pcb __diagused; 781 struct vm_map *map; 782 vaddr_t fault_pc, va; 783 ksiginfo_t ksi; 784 int error, user; 785 786 UVMHIST_FUNC(__func__); 787 UVMHIST_CALLED(maphist); 788 789 /* Update vmmeter statistics */ 790 curcpu()->ci_data.cpu_ntrap++; 791 792 l = curlwp; 793 pcb = lwp_getpcb(l); 794 795 if ((user = TRAP_USERMODE(tf)) != 0) 796 LWP_CACHE_CREDS(l, l->l_proc); 797 798 /* 799 * Enable IRQ's (disabled by the abort) This always comes 800 * from user mode so we know interrupts were not disabled. 801 * But we check anyway. 802 */ 803 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 804 if (__predict_true((tf->tf_spsr & I32_bit) != IF32_bits)) 805 restore_interrupts(tf->tf_spsr & IF32_bits); 806 807 /* See if the CPU state needs to be fixed up */ 808 switch (prefetch_abort_fixup(tf)) { 809 case ABORT_FIXUP_RETURN: 810 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 811 return; 812 case ABORT_FIXUP_FAILED: 813 /* Deliver a SIGILL to the process */ 814 KSI_INIT_TRAP(&ksi); 815 ksi.ksi_signo = SIGILL; 816 ksi.ksi_code = ILL_ILLOPC; 817 ksi.ksi_addr = (uint32_t *)(intptr_t) tf->tf_pc; 818 lwp_settrapframe(l, tf); 819 goto do_trapsignal; 820 default: 821 break; 822 } 823 824 /* Prefetch aborts cannot happen in kernel mode */ 825 if (__predict_false(!user)) 826 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 827 828 /* Get fault address */ 829 fault_pc = tf->tf_pc; 830 lwp_settrapframe(l, tf); 831 UVMHIST_LOG(maphist, " (pc=0x%x, l=0x%x, tf=0x%x)", 832 fault_pc, l, tf, 0); 833 834 /* Ok validate the address, can only execute in USER space */ 835 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 836 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 837 KSI_INIT_TRAP(&ksi); 838 ksi.ksi_signo = SIGSEGV; 839 ksi.ksi_code = SEGV_ACCERR; 840 ksi.ksi_addr = (uint32_t *)(intptr_t) fault_pc; 841 ksi.ksi_trap = fault_pc; 842 goto do_trapsignal; 843 } 844 845 map = &l->l_proc->p_vmspace->vm_map; 846 va = trunc_page(fault_pc); 847 848 /* 849 * See if the pmap can handle this fault on its own... 850 */ 851 #ifdef DEBUG 852 last_fault_code = -1; 853 #endif 854 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ|VM_PROT_EXECUTE, 1)) { 855 UVMHIST_LOG (maphist, " <- emulated", 0, 0, 0, 0); 856 goto out; 857 } 858 859 #ifdef DIAGNOSTIC 860 if (__predict_false(curcpu()->ci_intr_depth > 0)) { 861 printf("\nNon-emulated prefetch abort with intr_depth > 0\n"); 862 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 863 } 864 #endif 865 866 KASSERT(pcb->pcb_onfault == NULL); 867 error = uvm_fault(map, va, VM_PROT_READ|VM_PROT_EXECUTE); 868 869 if (__predict_true(error == 0)) { 870 UVMHIST_LOG (maphist, " <- uvm", 0, 0, 0, 0); 871 goto out; 872 } 873 KSI_INIT_TRAP(&ksi); 874 875 UVMHIST_LOG (maphist, " <- fatal (%d)", error, 0, 0, 0); 876 877 if (error == ENOMEM) { 878 printf("UVM: pid %d (%s), uid %d killed: " 879 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 880 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 881 ksi.ksi_signo = SIGKILL; 882 } else 883 ksi.ksi_signo = SIGSEGV; 884 885 ksi.ksi_code = SEGV_MAPERR; 886 ksi.ksi_addr = (uint32_t *)(intptr_t) fault_pc; 887 ksi.ksi_trap = fault_pc; 888 889 do_trapsignal: 890 call_trapsignal(l, tf, &ksi); 891 892 out: 893 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 894 userret(l); 895 } 896 897 /* 898 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 899 * If the read succeeds, the value is written to 'rptr' and zero is returned. 900 * Else, return EFAULT. 901 */ 902 int 903 badaddr_read(void *addr, size_t size, void *rptr) 904 { 905 extern int badaddr_read_1(const uint8_t *, uint8_t *); 906 extern int badaddr_read_2(const uint16_t *, uint16_t *); 907 extern int badaddr_read_4(const uint32_t *, uint32_t *); 908 union { 909 uint8_t v1; 910 uint16_t v2; 911 uint32_t v4; 912 } u; 913 int rv, s; 914 915 cpu_drain_writebuf(); 916 917 s = splhigh(); 918 919 /* Read from the test address. */ 920 switch (size) { 921 case sizeof(uint8_t): 922 rv = badaddr_read_1(addr, &u.v1); 923 if (rv == 0 && rptr) 924 *(uint8_t *) rptr = u.v1; 925 break; 926 927 case sizeof(uint16_t): 928 rv = badaddr_read_2(addr, &u.v2); 929 if (rv == 0 && rptr) 930 *(uint16_t *) rptr = u.v2; 931 break; 932 933 case sizeof(uint32_t): 934 rv = badaddr_read_4(addr, &u.v4); 935 if (rv == 0 && rptr) 936 *(uint32_t *) rptr = u.v4; 937 break; 938 939 default: 940 panic("%s: invalid size (%zu)", __func__, size); 941 } 942 943 splx(s); 944 945 /* Return EFAULT if the address was invalid, else zero */ 946 return (rv); 947 } 948