fault.c revision 1.94
1 /* $NetBSD: fault.c,v 1.94 2014/02/25 09:54:33 matt 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 1.94 2014/02/25 09:54:33 matt 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__); UVMHIST_CALLED(maphist); 246 247 /* Grab FAR/FSR before enabling interrupts */ 248 far = cpu_faultaddress(); 249 fsr = cpu_faultstatus(); 250 251 /* Update vmmeter statistics */ 252 ci->ci_data.cpu_ntrap++; 253 254 /* Re-enable interrupts if they were enabled previously */ 255 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 256 if (__predict_true((tf->tf_spsr & IF32_bits) != IF32_bits)) 257 restore_interrupts(tf->tf_spsr & IF32_bits); 258 259 /* Get the current lwp structure */ 260 261 UVMHIST_LOG(maphist, " (l=%#x, far=%#x, fsr=%#x", 262 l, far, fsr, 0); 263 UVMHIST_LOG(maphist, " tf=%#x, pc=%#x)", 264 tf, tf->tf_pc, 0, 0); 265 266 /* Data abort came from user mode? */ 267 bool user = (TRAP_USERMODE(tf) != 0); 268 if (user) 269 LWP_CACHE_CREDS(l, l->l_proc); 270 271 /* Grab the current pcb */ 272 struct pcb * const pcb = lwp_getpcb(l); 273 274 curcpu()->ci_abt_evs[fsr & FAULT_TYPE_MASK].ev_count++; 275 276 /* Invoke the appropriate handler, if necessary */ 277 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 278 #ifdef DIAGNOSTIC 279 printf("%s: data_aborts fsr=0x%x far=0x%x\n", 280 __func__, fsr, far); 281 #endif 282 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 283 l, &ksi)) 284 goto do_trapsignal; 285 goto out; 286 } 287 288 /* 289 * At this point, we're dealing with one of the following data aborts: 290 * 291 * FAULT_TRANS_S - Translation -- Section 292 * FAULT_TRANS_P - Translation -- Page 293 * FAULT_DOMAIN_S - Domain -- Section 294 * FAULT_DOMAIN_P - Domain -- Page 295 * FAULT_PERM_S - Permission -- Section 296 * FAULT_PERM_P - Permission -- Page 297 * 298 * These are the main virtual memory-related faults signalled by 299 * the MMU. 300 */ 301 302 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 303 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 304 tf->tf_r0 = EFAULT; 305 tf->tf_pc = (intptr_t) pcb->pcb_onfault; 306 return; 307 } 308 309 if (user) { 310 lwp_settrapframe(l, tf); 311 } 312 313 /* 314 * Make sure the Program Counter is sane. We could fall foul of 315 * someone executing Thumb code, in which case the PC might not 316 * be word-aligned. This would cause a kernel alignment fault 317 * further down if we have to decode the current instruction. 318 */ 319 #ifdef THUMB_CODE 320 /* 321 * XXX: It would be nice to be able to support Thumb in the kernel 322 * at some point. 323 */ 324 if (__predict_false(!user && (tf->tf_pc & 3) != 0)) { 325 printf("\n%s: Misaligned Kernel-mode Program Counter\n", 326 __func__); 327 dab_fatal(tf, fsr, far, l, NULL); 328 } 329 #else 330 if (__predict_false((tf->tf_pc & 3) != 0)) { 331 if (user) { 332 /* 333 * Give the user an illegal instruction signal. 334 */ 335 /* Deliver a SIGILL to the process */ 336 KSI_INIT_TRAP(&ksi); 337 ksi.ksi_signo = SIGILL; 338 ksi.ksi_code = ILL_ILLOPC; 339 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 340 ksi.ksi_trap = fsr; 341 goto do_trapsignal; 342 } 343 344 /* 345 * The kernel never executes Thumb code. 346 */ 347 printf("\n%s: Misaligned Kernel-mode Program Counter\n", 348 __func__); 349 dab_fatal(tf, fsr, far, l, NULL); 350 } 351 #endif 352 353 /* See if the CPU state needs to be fixed up */ 354 switch (data_abort_fixup(tf, fsr, far, l)) { 355 case ABORT_FIXUP_RETURN: 356 return; 357 case ABORT_FIXUP_FAILED: 358 /* Deliver a SIGILL to the process */ 359 KSI_INIT_TRAP(&ksi); 360 ksi.ksi_signo = SIGILL; 361 ksi.ksi_code = ILL_ILLOPC; 362 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 363 ksi.ksi_trap = fsr; 364 goto do_trapsignal; 365 default: 366 break; 367 } 368 369 va = trunc_page((vaddr_t)far); 370 371 /* 372 * It is only a kernel address space fault iff: 373 * 1. user == 0 and 374 * 2. pcb_onfault not set or 375 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 376 */ 377 if (!user && (va >= VM_MIN_KERNEL_ADDRESS || 378 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 379 __predict_true((pcb->pcb_onfault == NULL || 380 (read_insn(tf->tf_pc, false) & 0x05200000) != 0x04200000))) { 381 map = kernel_map; 382 383 /* Was the fault due to the FPE/IPKDB ? */ 384 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 385 KSI_INIT_TRAP(&ksi); 386 ksi.ksi_signo = SIGSEGV; 387 ksi.ksi_code = SEGV_ACCERR; 388 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 389 ksi.ksi_trap = fsr; 390 391 /* 392 * Force exit via userret() 393 * This is necessary as the FPE is an extension to 394 * userland that actually runs in a priveledged mode 395 * but uses USR mode permissions for its accesses. 396 */ 397 user = true; 398 goto do_trapsignal; 399 } 400 } else { 401 map = &l->l_proc->p_vmspace->vm_map; 402 } 403 404 /* 405 * We need to know whether the page should be mapped as R or R/W. 406 * Before ARMv6, the MMU did not give us the info as to whether the 407 * fault was caused by a read or a write. 408 * 409 * However, we know that a permission fault can only be the result of 410 * a write to a read-only location, so we can deal with those quickly. 411 * 412 * Otherwise we need to disassemble the instruction responsible to 413 * determine if it was a write. 414 */ 415 if (CPU_IS_ARMV6_P() || CPU_IS_ARMV7_P()) { 416 ftype = (fsr & FAULT_WRITE) ? VM_PROT_WRITE : VM_PROT_READ; 417 } else if (IS_PERMISSION_FAULT(fsr)) { 418 ftype = VM_PROT_WRITE; 419 } else { 420 #ifdef THUMB_CODE 421 /* Fast track the ARM case. */ 422 if (__predict_false(tf->tf_spsr & PSR_T_bit)) { 423 u_int insn = read_thumb_insn(tf->tf_pc, user); 424 u_int insn_f8 = insn & 0xf800; 425 u_int insn_fe = insn & 0xfe00; 426 427 if (insn_f8 == 0x6000 || /* STR(1) */ 428 insn_f8 == 0x7000 || /* STRB(1) */ 429 insn_f8 == 0x8000 || /* STRH(1) */ 430 insn_f8 == 0x9000 || /* STR(3) */ 431 insn_f8 == 0xc000 || /* STM */ 432 insn_fe == 0x5000 || /* STR(2) */ 433 insn_fe == 0x5200 || /* STRH(2) */ 434 insn_fe == 0x5400) /* STRB(2) */ 435 ftype = VM_PROT_WRITE; 436 else 437 ftype = VM_PROT_READ; 438 } 439 else 440 #endif 441 { 442 u_int insn = read_insn(tf->tf_pc, user); 443 444 if (((insn & 0x0c100000) == 0x04000000) || /* STR[B] */ 445 ((insn & 0x0e1000b0) == 0x000000b0) || /* STR[HD]*/ 446 ((insn & 0x0a100000) == 0x08000000) || /* STM/CDT*/ 447 ((insn & 0x0f9000f0) == 0x01800090)) /* STREX[BDH] */ 448 ftype = VM_PROT_WRITE; 449 else if ((insn & 0x0fb00ff0) == 0x01000090)/* SWP */ 450 ftype = VM_PROT_READ | VM_PROT_WRITE; 451 else 452 ftype = VM_PROT_READ; 453 } 454 } 455 456 /* 457 * See if the fault is as a result of ref/mod emulation, 458 * or domain mismatch. 459 */ 460 #ifdef DEBUG 461 last_fault_code = fsr; 462 #endif 463 if (pmap_fault_fixup(map->pmap, va, ftype, user)) { 464 UVMHIST_LOG(maphist, " <- ref/mod emul", 0, 0, 0, 0); 465 goto out; 466 } 467 468 if (__predict_false(curcpu()->ci_intr_depth > 0)) { 469 if (pcb->pcb_onfault) { 470 tf->tf_r0 = EINVAL; 471 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 472 return; 473 } 474 printf("\nNon-emulated page fault with intr_depth > 0\n"); 475 dab_fatal(tf, fsr, far, l, NULL); 476 } 477 478 onfault = pcb->pcb_onfault; 479 pcb->pcb_onfault = NULL; 480 error = uvm_fault(map, va, ftype); 481 pcb->pcb_onfault = onfault; 482 483 if (__predict_true(error == 0)) { 484 if (user) 485 uvm_grow(l->l_proc, va); /* Record any stack growth */ 486 else 487 ucas_ras_check(tf); 488 UVMHIST_LOG(maphist, " <- uvm", 0, 0, 0, 0); 489 goto out; 490 } 491 492 if (user == 0) { 493 if (pcb->pcb_onfault) { 494 tf->tf_r0 = error; 495 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 496 return; 497 } 498 499 printf("\nuvm_fault(%p, %lx, %x) -> %x\n", map, va, ftype, 500 error); 501 dab_fatal(tf, fsr, far, l, NULL); 502 } 503 504 KSI_INIT_TRAP(&ksi); 505 506 if (error == ENOMEM) { 507 printf("UVM: pid %d (%s), uid %d killed: " 508 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 509 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 510 ksi.ksi_signo = SIGKILL; 511 } else 512 ksi.ksi_signo = SIGSEGV; 513 514 ksi.ksi_code = (error == EACCES) ? SEGV_ACCERR : SEGV_MAPERR; 515 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 516 ksi.ksi_trap = fsr; 517 UVMHIST_LOG(maphist, " <- error (%d)", error, 0, 0, 0); 518 519 do_trapsignal: 520 call_trapsignal(l, tf, &ksi); 521 out: 522 /* If returning to user mode, make sure to invoke userret() */ 523 if (user) 524 userret(l); 525 } 526 527 /* 528 * dab_fatal() handles the following data aborts: 529 * 530 * FAULT_WRTBUF_0 - Vector Exception 531 * FAULT_WRTBUF_1 - Terminal Exception 532 * 533 * We should never see these on a properly functioning system. 534 * 535 * This function is also called by the other handlers if they 536 * detect a fatal problem. 537 * 538 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 539 */ 540 static int 541 dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 542 { 543 const char * const mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 544 545 if (l != NULL) { 546 printf("Fatal %s mode data abort: '%s'\n", mode, 547 data_aborts[fsr & FAULT_TYPE_MASK].desc); 548 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 549 if ((fsr & FAULT_IMPRECISE) == 0) 550 printf("%08x, ", far); 551 else 552 printf("Invalid, "); 553 printf("spsr=%08x\n", tf->tf_spsr); 554 } else { 555 printf("Fatal %s mode prefetch abort at 0x%08x\n", 556 mode, tf->tf_pc); 557 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 558 } 559 560 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 561 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 562 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 563 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 564 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 565 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 566 printf("r12=%08x, ", tf->tf_r12); 567 568 if (TRAP_USERMODE(tf)) 569 printf("usp=%08x, ulr=%08x", 570 tf->tf_usr_sp, tf->tf_usr_lr); 571 else 572 printf("ssp=%08x, slr=%08x", 573 tf->tf_svc_sp, tf->tf_svc_lr); 574 printf(", pc =%08x\n\n", tf->tf_pc); 575 576 #if defined(DDB) || defined(KGDB) 577 kdb_trap(T_FAULT, tf); 578 #endif 579 panic("Fatal abort"); 580 /*NOTREACHED*/ 581 } 582 583 /* 584 * dab_align() handles the following data aborts: 585 * 586 * FAULT_ALIGN_0 - Alignment fault 587 * FAULT_ALIGN_0 - Alignment fault 588 * 589 * These faults are fatal if they happen in kernel mode. Otherwise, we 590 * deliver a bus error to the process. 591 */ 592 static int 593 dab_align(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 594 { 595 /* Alignment faults are always fatal if they occur in kernel mode */ 596 if (!TRAP_USERMODE(tf)) 597 dab_fatal(tf, fsr, far, l, NULL); 598 599 /* pcb_onfault *must* be NULL at this point */ 600 KDASSERT(((struct pcb *)lwp_getpcb(l))->pcb_onfault == NULL); 601 602 /* See if the CPU state needs to be fixed up */ 603 (void) data_abort_fixup(tf, fsr, far, l); 604 605 /* Deliver a bus error signal to the process */ 606 KSI_INIT_TRAP(ksi); 607 ksi->ksi_signo = SIGBUS; 608 ksi->ksi_code = BUS_ADRALN; 609 ksi->ksi_addr = (uint32_t *)(intptr_t)far; 610 ksi->ksi_trap = fsr; 611 612 lwp_settrapframe(l, tf); 613 614 return (1); 615 } 616 617 /* 618 * dab_buserr() handles the following data aborts: 619 * 620 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 621 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 622 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 623 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 624 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 625 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 626 * 627 * If pcb_onfault is set, flag the fault and return to the handler. 628 * If the fault occurred in user mode, give the process a SIGBUS. 629 * 630 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 631 * can be flagged as imprecise in the FSR. This causes a real headache 632 * since some of the machine state is lost. In this case, tf->tf_pc 633 * may not actually point to the offending instruction. In fact, if 634 * we've taken a double abort fault, it generally points somewhere near 635 * the top of "data_abort_entry" in exception.S. 636 * 637 * In all other cases, these data aborts are considered fatal. 638 */ 639 static int 640 dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, 641 ksiginfo_t *ksi) 642 { 643 struct pcb *pcb = lwp_getpcb(l); 644 645 #ifdef __XSCALE__ 646 if ((fsr & FAULT_IMPRECISE) != 0 && 647 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 648 /* 649 * Oops, an imprecise, double abort fault. We've lost the 650 * r14_abt/spsr_abt values corresponding to the original 651 * abort, and the spsr saved in the trapframe indicates 652 * ABT mode. 653 */ 654 tf->tf_spsr &= ~PSR_MODE; 655 656 /* 657 * We use a simple heuristic to determine if the double abort 658 * happened as a result of a kernel or user mode access. 659 * If the current trapframe is at the top of the kernel stack, 660 * the fault _must_ have come from user mode. 661 */ 662 if (tf != ((trapframe_t *)pcb->pcb_ksp) - 1) { 663 /* 664 * Kernel mode. We're either about to die a 665 * spectacular death, or pcb_onfault will come 666 * to our rescue. Either way, the current value 667 * of tf->tf_pc is irrelevant. 668 */ 669 tf->tf_spsr |= PSR_SVC32_MODE; 670 if (pcb->pcb_onfault == NULL) 671 printf("\nKernel mode double abort!\n"); 672 } else { 673 /* 674 * User mode. We've lost the program counter at the 675 * time of the fault (not that it was accurate anyway; 676 * it's not called an imprecise fault for nothing). 677 * About all we can do is copy r14_usr to tf_pc and 678 * hope for the best. The process is about to get a 679 * SIGBUS, so it's probably history anyway. 680 */ 681 tf->tf_spsr |= PSR_USR32_MODE; 682 tf->tf_pc = tf->tf_usr_lr; 683 #ifdef THUMB_CODE 684 tf->tf_spsr &= ~PSR_T_bit; 685 if (tf->tf_usr_lr & 1) 686 tf->tf_spsr |= PSR_T_bit; 687 #endif 688 } 689 } 690 691 /* FAR is invalid for imprecise exceptions */ 692 if ((fsr & FAULT_IMPRECISE) != 0) 693 far = 0; 694 #endif /* __XSCALE__ */ 695 696 if (pcb->pcb_onfault) { 697 KDASSERT(TRAP_USERMODE(tf) == 0); 698 tf->tf_r0 = EFAULT; 699 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 700 return (0); 701 } 702 703 /* See if the CPU state needs to be fixed up */ 704 (void) data_abort_fixup(tf, fsr, far, l); 705 706 /* 707 * At this point, if the fault happened in kernel mode, we're toast 708 */ 709 if (!TRAP_USERMODE(tf)) 710 dab_fatal(tf, fsr, far, l, NULL); 711 712 /* Deliver a bus error signal to the process */ 713 KSI_INIT_TRAP(ksi); 714 ksi->ksi_signo = SIGBUS; 715 ksi->ksi_code = BUS_ADRERR; 716 ksi->ksi_addr = (uint32_t *)(intptr_t)far; 717 ksi->ksi_trap = fsr; 718 719 lwp_settrapframe(l, tf); 720 721 return (1); 722 } 723 724 static inline int 725 prefetch_abort_fixup(trapframe_t *tf) 726 { 727 #ifdef CPU_ABORT_FIXUP_REQUIRED 728 int error; 729 730 /* Call the CPU specific prefetch abort fixup routine */ 731 error = cpu_prefetchabt_fixup(tf); 732 if (__predict_true(error != ABORT_FIXUP_FAILED)) 733 return (error); 734 735 /* 736 * Oops, couldn't fix up the instruction 737 */ 738 printf("%s: fixup for %s mode prefetch abort failed.\n", __func__, 739 TRAP_USERMODE(tf) ? "user" : "kernel"); 740 #ifdef THUMB_CODE 741 if (tf->tf_spsr & PSR_T_bit) { 742 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 743 tf->tf_pc, *((uint16 *)(tf->tf_pc & ~1)), 744 *((uint16 *)((tf->tf_pc + 2) & ~1))); 745 } 746 else 747 #endif 748 { 749 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 750 *((u_int *)tf->tf_pc)); 751 } 752 disassemble(tf->tf_pc); 753 754 /* Die now if this happened in kernel mode */ 755 if (!TRAP_USERMODE(tf)) 756 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 757 758 return (error); 759 #else 760 return (ABORT_FIXUP_OK); 761 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 762 } 763 764 /* 765 * void prefetch_abort_handler(trapframe_t *tf) 766 * 767 * Abort handler called when instruction execution occurs at 768 * a non existent or restricted (access permissions) memory page. 769 * If the address is invalid and we were in SVC mode then panic as 770 * the kernel should never prefetch abort. 771 * If the address is invalid and the page is mapped then the user process 772 * does no have read permission so send it a signal. 773 * Otherwise fault the page in and try again. 774 */ 775 void 776 prefetch_abort_handler(trapframe_t *tf) 777 { 778 struct lwp *l; 779 struct pcb *pcb __diagused; 780 struct vm_map *map; 781 vaddr_t fault_pc, va; 782 ksiginfo_t ksi; 783 int error, user; 784 785 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 786 787 /* Update vmmeter statistics */ 788 curcpu()->ci_data.cpu_ntrap++; 789 790 l = curlwp; 791 pcb = lwp_getpcb(l); 792 793 if ((user = TRAP_USERMODE(tf)) != 0) 794 LWP_CACHE_CREDS(l, l->l_proc); 795 796 /* 797 * Enable IRQ's (disabled by the abort) This always comes 798 * from user mode so we know interrupts were not disabled. 799 * But we check anyway. 800 */ 801 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 802 if (__predict_true((tf->tf_spsr & I32_bit) != IF32_bits)) 803 restore_interrupts(tf->tf_spsr & IF32_bits); 804 805 /* See if the CPU state needs to be fixed up */ 806 switch (prefetch_abort_fixup(tf)) { 807 case ABORT_FIXUP_RETURN: 808 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 809 return; 810 case ABORT_FIXUP_FAILED: 811 /* Deliver a SIGILL to the process */ 812 KSI_INIT_TRAP(&ksi); 813 ksi.ksi_signo = SIGILL; 814 ksi.ksi_code = ILL_ILLOPC; 815 ksi.ksi_addr = (uint32_t *)(intptr_t) tf->tf_pc; 816 lwp_settrapframe(l, tf); 817 goto do_trapsignal; 818 default: 819 break; 820 } 821 822 /* Prefetch aborts cannot happen in kernel mode */ 823 if (__predict_false(!user)) 824 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 825 826 /* Get fault address */ 827 fault_pc = tf->tf_pc; 828 lwp_settrapframe(l, tf); 829 UVMHIST_LOG(maphist, " (pc=0x%x, l=0x%x, tf=0x%x)", fault_pc, l, tf, 830 0); 831 832 /* Ok validate the address, can only execute in USER space */ 833 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 834 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 835 KSI_INIT_TRAP(&ksi); 836 ksi.ksi_signo = SIGSEGV; 837 ksi.ksi_code = SEGV_ACCERR; 838 ksi.ksi_addr = (uint32_t *)(intptr_t) fault_pc; 839 ksi.ksi_trap = fault_pc; 840 goto do_trapsignal; 841 } 842 843 map = &l->l_proc->p_vmspace->vm_map; 844 va = trunc_page(fault_pc); 845 846 /* 847 * See if the pmap can handle this fault on its own... 848 */ 849 #ifdef DEBUG 850 last_fault_code = -1; 851 #endif 852 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ|VM_PROT_EXECUTE, 1)) { 853 UVMHIST_LOG (maphist, " <- emulated", 0, 0, 0, 0); 854 goto out; 855 } 856 857 #ifdef DIAGNOSTIC 858 if (__predict_false(curcpu()->ci_intr_depth > 0)) { 859 printf("\nNon-emulated prefetch abort with intr_depth > 0\n"); 860 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 861 } 862 #endif 863 864 KASSERT(pcb->pcb_onfault == NULL); 865 error = uvm_fault(map, va, VM_PROT_READ); 866 867 if (__predict_true(error == 0)) { 868 UVMHIST_LOG (maphist, " <- uvm", 0, 0, 0, 0); 869 goto out; 870 } 871 KSI_INIT_TRAP(&ksi); 872 873 UVMHIST_LOG (maphist, " <- fatal (%d)", error, 0, 0, 0); 874 if (error == ENOMEM) { 875 printf("UVM: pid %d (%s), uid %d killed: " 876 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 877 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 878 ksi.ksi_signo = SIGKILL; 879 } else 880 ksi.ksi_signo = SIGSEGV; 881 882 ksi.ksi_code = SEGV_MAPERR; 883 ksi.ksi_addr = (uint32_t *)(intptr_t) fault_pc; 884 ksi.ksi_trap = fault_pc; 885 886 do_trapsignal: 887 call_trapsignal(l, tf, &ksi); 888 889 out: 890 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 891 userret(l); 892 } 893 894 /* 895 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 896 * If the read succeeds, the value is written to 'rptr' and zero is returned. 897 * Else, return EFAULT. 898 */ 899 int 900 badaddr_read(void *addr, size_t size, void *rptr) 901 { 902 extern int badaddr_read_1(const uint8_t *, uint8_t *); 903 extern int badaddr_read_2(const uint16_t *, uint16_t *); 904 extern int badaddr_read_4(const uint32_t *, uint32_t *); 905 union { 906 uint8_t v1; 907 uint16_t v2; 908 uint32_t v4; 909 } u; 910 int rv, s; 911 912 cpu_drain_writebuf(); 913 914 s = splhigh(); 915 916 /* Read from the test address. */ 917 switch (size) { 918 case sizeof(uint8_t): 919 rv = badaddr_read_1(addr, &u.v1); 920 if (rv == 0 && rptr) 921 *(uint8_t *) rptr = u.v1; 922 break; 923 924 case sizeof(uint16_t): 925 rv = badaddr_read_2(addr, &u.v2); 926 if (rv == 0 && rptr) 927 *(uint16_t *) rptr = u.v2; 928 break; 929 930 case sizeof(uint32_t): 931 rv = badaddr_read_4(addr, &u.v4); 932 if (rv == 0 && rptr) 933 *(uint32_t *) rptr = u.v4; 934 break; 935 936 default: 937 panic("%s: invalid size (%zu)", __func__, size); 938 } 939 940 splx(s); 941 942 /* Return EFAULT if the address was invalid, else zero */ 943 return (rv); 944 } 945
Indexes created Wed Sep 24 15:09:51 GMT 2025