fault.c revision 1.78.12.1
1 /* $NetBSD: fault.c,v 1.78.12.1 2012/02/18 07:31:23 mrg 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 #include "opt_sa.h" 83 84 #include <sys/types.h> 85 __KERNEL_RCSID(0, "$NetBSD: fault.c,v 1.78.12.1 2012/02/18 07:31:23 mrg Exp $"); 86 87 #include <sys/param.h> 88 #include <sys/systm.h> 89 #include <sys/proc.h> 90 #include <sys/kernel.h> 91 #include <sys/kauth.h> 92 93 #include <sys/savar.h> 94 #include <sys/cpu.h> 95 96 #include <uvm/uvm_extern.h> 97 #include <uvm/uvm_stat.h> 98 #ifdef UVMHIST 99 #include <uvm/uvm.h> 100 #endif 101 102 #include <arm/cpuconf.h> 103 104 #include <machine/frame.h> 105 #include <arm/arm32/katelib.h> 106 #include <machine/intr.h> 107 #if defined(DDB) || defined(KGDB) 108 #include <machine/db_machdep.h> 109 #ifdef KGDB 110 #include <sys/kgdb.h> 111 #endif 112 #if !defined(DDB) 113 #define kdb_trap kgdb_trap 114 #endif 115 #endif 116 117 #include <arch/arm/arm/disassem.h> 118 #include <arm/arm32/machdep.h> 119 120 extern char fusubailout[]; 121 122 #ifdef DEBUG 123 int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 124 #endif 125 126 #if defined(CPU_ARM3) || defined(CPU_ARM6) || \ 127 defined(CPU_ARM7) || defined(CPU_ARM7TDMI) 128 /* These CPUs may need data/prefetch abort fixups */ 129 #define CPU_ABORT_FIXUP_REQUIRED 130 #endif 131 132 struct data_abort { 133 int (*func)(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 134 const char *desc; 135 }; 136 137 static int dab_fatal(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 138 static int dab_align(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 139 static int dab_buserr(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 140 141 static const struct data_abort data_aborts[] = { 142 {dab_fatal, "Vector Exception"}, 143 {dab_align, "Alignment Fault 1"}, 144 {dab_fatal, "Terminal Exception"}, 145 {dab_align, "Alignment Fault 3"}, 146 {dab_buserr, "External Linefetch Abort (S)"}, 147 {NULL, "Translation Fault (S)"}, 148 {dab_buserr, "External Linefetch Abort (P)"}, 149 {NULL, "Translation Fault (P)"}, 150 {dab_buserr, "External Non-Linefetch Abort (S)"}, 151 {NULL, "Domain Fault (S)"}, 152 {dab_buserr, "External Non-Linefetch Abort (P)"}, 153 {NULL, "Domain Fault (P)"}, 154 {dab_buserr, "External Translation Abort (L1)"}, 155 {NULL, "Permission Fault (S)"}, 156 {dab_buserr, "External Translation Abort (L2)"}, 157 {NULL, "Permission Fault (P)"} 158 }; 159 160 /* Determine if a fault came from user mode */ 161 #define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE) 162 163 /* Determine if 'x' is a permission fault */ 164 #define IS_PERMISSION_FAULT(x) \ 165 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 166 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 167 168 #if 0 169 /* maybe one day we'll do emulations */ 170 #define TRAPSIGNAL(l,k) (*(l)->l_proc->p_emul->e_trapsignal)((l), (k)) 171 #else 172 #define TRAPSIGNAL(l,k) trapsignal((l), (k)) 173 #endif 174 175 static inline void 176 call_trapsignal(struct lwp *l, ksiginfo_t *ksi) 177 { 178 179 TRAPSIGNAL(l, ksi); 180 } 181 182 static inline int 183 data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l) 184 { 185 #ifdef CPU_ABORT_FIXUP_REQUIRED 186 int error; 187 188 /* Call the CPU specific data abort fixup routine */ 189 error = cpu_dataabt_fixup(tf); 190 if (__predict_true(error != ABORT_FIXUP_FAILED)) 191 return (error); 192 193 /* 194 * Oops, couldn't fix up the instruction 195 */ 196 printf("%s: fixup for %s mode data abort failed.\n", __func__, 197 TRAP_USERMODE(tf) ? "user" : "kernel"); 198 #ifdef THUMB_CODE 199 if (tf->tf_spsr & PSR_T_bit) { 200 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 201 tf->tf_pc, *((u_int16 *)(tf->tf_pc & ~1)), 202 *((u_int16 *)((tf->tf_pc + 2) & ~1))); 203 } 204 else 205 #endif 206 { 207 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 208 *((u_int *)tf->tf_pc)); 209 } 210 disassemble(tf->tf_pc); 211 212 /* Die now if this happened in kernel mode */ 213 if (!TRAP_USERMODE(tf)) 214 dab_fatal(tf, fsr, far, l, NULL); 215 216 return (error); 217 #else 218 return (ABORT_FIXUP_OK); 219 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 220 } 221 222 void 223 data_abort_handler(trapframe_t *tf) 224 { 225 struct vm_map *map; 226 struct pcb *pcb; 227 struct lwp *l; 228 u_int user, far, fsr; 229 vm_prot_t ftype; 230 void *onfault; 231 vaddr_t va; 232 int error; 233 ksiginfo_t ksi; 234 235 UVMHIST_FUNC("data_abort_handler"); 236 237 /* Grab FAR/FSR before enabling interrupts */ 238 far = cpu_faultaddress(); 239 fsr = cpu_faultstatus(); 240 241 UVMHIST_CALLED(maphist); 242 /* Update vmmeter statistics */ 243 curcpu()->ci_data.cpu_ntrap++; 244 245 /* Re-enable interrupts if they were enabled previously */ 246 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 247 if (__predict_true((tf->tf_spsr & IF32_bits) != IF32_bits)) 248 restore_interrupts(tf->tf_spsr & IF32_bits); 249 250 /* Get the current lwp structure */ 251 KASSERT(curlwp != NULL); 252 l = curlwp; 253 254 UVMHIST_LOG(maphist, " (pc=0x%x, l=0x%x, far=0x%x, fsr=0x%x)", 255 tf->tf_pc, l, far, fsr); 256 257 /* Data abort came from user mode? */ 258 if ((user = TRAP_USERMODE(tf)) != 0) 259 LWP_CACHE_CREDS(l, l->l_proc); 260 261 /* Grab the current pcb */ 262 pcb = lwp_getpcb(l); 263 264 /* Invoke the appropriate handler, if necessary */ 265 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 266 #ifdef DIAGNOSTIC 267 printf("%s: data_aborts fsr=0x%x far=0x%x\n", 268 __func__, fsr, far); 269 #endif 270 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 271 l, &ksi)) 272 goto do_trapsignal; 273 goto out; 274 } 275 276 /* 277 * At this point, we're dealing with one of the following data aborts: 278 * 279 * FAULT_TRANS_S - Translation -- Section 280 * FAULT_TRANS_P - Translation -- Page 281 * FAULT_DOMAIN_S - Domain -- Section 282 * FAULT_DOMAIN_P - Domain -- Page 283 * FAULT_PERM_S - Permission -- Section 284 * FAULT_PERM_P - Permission -- Page 285 * 286 * These are the main virtual memory-related faults signalled by 287 * the MMU. 288 */ 289 290 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 291 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 292 tf->tf_r0 = EFAULT; 293 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 294 return; 295 } 296 297 if (user) { 298 pcb->pcb_tf = tf; 299 } 300 301 /* 302 * Make sure the Program Counter is sane. We could fall foul of 303 * someone executing Thumb code, in which case the PC might not 304 * be word-aligned. This would cause a kernel alignment fault 305 * further down if we have to decode the current instruction. 306 */ 307 #ifdef THUMB_CODE 308 /* 309 * XXX: It would be nice to be able to support Thumb in the kernel 310 * at some point. 311 */ 312 if (__predict_false(!user && (tf->tf_pc & 3) != 0)) { 313 printf("\n%s: Misaligned Kernel-mode Program Counter\n", 314 __func__); 315 dab_fatal(tf, fsr, far, l, NULL); 316 } 317 #else 318 if (__predict_false((tf->tf_pc & 3) != 0)) { 319 if (user) { 320 /* 321 * Give the user an illegal instruction signal. 322 */ 323 /* Deliver a SIGILL to the process */ 324 KSI_INIT_TRAP(&ksi); 325 ksi.ksi_signo = SIGILL; 326 ksi.ksi_code = ILL_ILLOPC; 327 ksi.ksi_addr = (u_int32_t *)(intptr_t) far; 328 ksi.ksi_trap = fsr; 329 goto do_trapsignal; 330 } 331 332 /* 333 * The kernel never executes Thumb code. 334 */ 335 printf("\n%s: Misaligned Kernel-mode Program Counter\n", 336 __func__); 337 dab_fatal(tf, fsr, far, l, NULL); 338 } 339 #endif 340 341 /* See if the CPU state needs to be fixed up */ 342 switch (data_abort_fixup(tf, fsr, far, l)) { 343 case ABORT_FIXUP_RETURN: 344 return; 345 case ABORT_FIXUP_FAILED: 346 /* Deliver a SIGILL to the process */ 347 KSI_INIT_TRAP(&ksi); 348 ksi.ksi_signo = SIGILL; 349 ksi.ksi_code = ILL_ILLOPC; 350 ksi.ksi_addr = (u_int32_t *)(intptr_t) far; 351 ksi.ksi_trap = fsr; 352 goto do_trapsignal; 353 default: 354 break; 355 } 356 357 va = trunc_page((vaddr_t)far); 358 359 /* 360 * It is only a kernel address space fault iff: 361 * 1. user == 0 and 362 * 2. pcb_onfault not set or 363 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 364 */ 365 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 366 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 367 __predict_true((pcb->pcb_onfault == NULL || 368 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 369 map = kernel_map; 370 371 /* Was the fault due to the FPE/IPKDB ? */ 372 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 373 KSI_INIT_TRAP(&ksi); 374 ksi.ksi_signo = SIGSEGV; 375 ksi.ksi_code = SEGV_ACCERR; 376 ksi.ksi_addr = (u_int32_t *)(intptr_t) far; 377 ksi.ksi_trap = fsr; 378 379 /* 380 * Force exit via userret() 381 * This is necessary as the FPE is an extension to 382 * userland that actually runs in a priveledged mode 383 * but uses USR mode permissions for its accesses. 384 */ 385 user = 1; 386 goto do_trapsignal; 387 } 388 } else { 389 map = &l->l_proc->p_vmspace->vm_map; 390 #ifdef KERN_SA 391 if ((l->l_flag & LW_SA) && (~l->l_pflag & LP_SA_NOBLOCK)) { 392 l->l_savp->savp_faultaddr = (vaddr_t)far; 393 l->l_pflag |= LP_SA_PAGEFAULT; 394 } 395 #endif 396 } 397 398 /* 399 * We need to know whether the page should be mapped 400 * as R or R/W. The MMU does not give us the info as 401 * to whether the fault was caused by a read or a write. 402 * 403 * However, we know that a permission fault can only be 404 * the result of a write to a read-only location, so 405 * we can deal with those quickly. 406 * 407 * Otherwise we need to disassemble the instruction 408 * responsible to determine if it was a write. 409 */ 410 if (IS_PERMISSION_FAULT(fsr)) 411 ftype = VM_PROT_WRITE; 412 else { 413 #ifdef THUMB_CODE 414 /* Fast track the ARM case. */ 415 if (__predict_false(tf->tf_spsr & PSR_T_bit)) { 416 u_int insn = fusword((void *)(tf->tf_pc & ~1)); 417 u_int insn_f8 = insn & 0xf800; 418 u_int insn_fe = insn & 0xfe00; 419 420 if (insn_f8 == 0x6000 || /* STR(1) */ 421 insn_f8 == 0x7000 || /* STRB(1) */ 422 insn_f8 == 0x8000 || /* STRH(1) */ 423 insn_f8 == 0x9000 || /* STR(3) */ 424 insn_f8 == 0xc000 || /* STM */ 425 insn_fe == 0x5000 || /* STR(2) */ 426 insn_fe == 0x5200 || /* STRH(2) */ 427 insn_fe == 0x5400) /* STRB(2) */ 428 ftype = VM_PROT_WRITE; 429 else 430 ftype = VM_PROT_READ; 431 } 432 else 433 #endif 434 { 435 u_int insn = ReadWord(tf->tf_pc); 436 437 if (((insn & 0x0c100000) == 0x04000000) || /* STR[B] */ 438 ((insn & 0x0e1000b0) == 0x000000b0) || /* STR[HD]*/ 439 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT*/ 440 ftype = VM_PROT_WRITE; 441 else if ((insn & 0x0fb00ff0) == 0x01000090)/* SWP */ 442 ftype = VM_PROT_READ | VM_PROT_WRITE; 443 else 444 ftype = VM_PROT_READ; 445 } 446 } 447 448 /* 449 * See if the fault is as a result of ref/mod emulation, 450 * or domain mismatch. 451 */ 452 #ifdef DEBUG 453 last_fault_code = fsr; 454 #endif 455 if (pmap_fault_fixup(map->pmap, va, ftype, user)) { 456 #ifdef KERN_SA 457 if (map != kernel_map) 458 l->l_pflag &= ~LP_SA_PAGEFAULT; 459 #endif 460 UVMHIST_LOG(maphist, " <- ref/mod emul", 0, 0, 0, 0); 461 goto out; 462 } 463 464 if (__predict_false(curcpu()->ci_intr_depth > 0)) { 465 if (pcb->pcb_onfault) { 466 tf->tf_r0 = EINVAL; 467 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 468 return; 469 } 470 printf("\nNon-emulated page fault with intr_depth > 0\n"); 471 dab_fatal(tf, fsr, far, l, NULL); 472 } 473 474 onfault = pcb->pcb_onfault; 475 pcb->pcb_onfault = NULL; 476 error = uvm_fault(map, va, ftype); 477 pcb->pcb_onfault = onfault; 478 479 #ifdef KERN_SA 480 if (map != kernel_map) 481 l->l_pflag &= ~LP_SA_PAGEFAULT; 482 #endif 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 = (u_int32_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, &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 *mode; 545 546 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 547 548 if (l != NULL) { 549 printf("Fatal %s mode data abort: '%s'\n", mode, 550 data_aborts[fsr & FAULT_TYPE_MASK].desc); 551 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 552 if ((fsr & FAULT_IMPRECISE) == 0) 553 printf("%08x, ", far); 554 else 555 printf("Invalid, "); 556 printf("spsr=%08x\n", tf->tf_spsr); 557 } else { 558 printf("Fatal %s mode prefetch abort at 0x%08x\n", 559 mode, tf->tf_pc); 560 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 561 } 562 563 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 564 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 565 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 566 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 567 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 568 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 569 printf("r12=%08x, ", tf->tf_r12); 570 571 if (TRAP_USERMODE(tf)) 572 printf("usp=%08x, ulr=%08x", 573 tf->tf_usr_sp, tf->tf_usr_lr); 574 else 575 printf("ssp=%08x, slr=%08x", 576 tf->tf_svc_sp, tf->tf_svc_lr); 577 printf(", pc =%08x\n\n", tf->tf_pc); 578 579 #if defined(DDB) || defined(KGDB) 580 kdb_trap(T_FAULT, tf); 581 #endif 582 panic("Fatal abort"); 583 /*NOTREACHED*/ 584 } 585 586 /* 587 * dab_align() handles the following data aborts: 588 * 589 * FAULT_ALIGN_0 - Alignment fault 590 * FAULT_ALIGN_0 - Alignment fault 591 * 592 * These faults are fatal if they happen in kernel mode. Otherwise, we 593 * deliver a bus error to the process. 594 */ 595 static int 596 dab_align(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 597 { 598 struct pcb *pcb = lwp_getpcb(l); 599 600 /* Alignment faults are always fatal if they occur in kernel mode */ 601 if (!TRAP_USERMODE(tf)) 602 dab_fatal(tf, fsr, far, l, NULL); 603 604 /* pcb_onfault *must* be NULL at this point */ 605 KDASSERT(pcb->pcb_onfault == NULL); 606 607 /* See if the CPU state needs to be fixed up */ 608 (void) data_abort_fixup(tf, fsr, far, l); 609 610 /* Deliver a bus error signal to the process */ 611 KSI_INIT_TRAP(ksi); 612 ksi->ksi_signo = SIGBUS; 613 ksi->ksi_code = BUS_ADRALN; 614 ksi->ksi_addr = (u_int32_t *)(intptr_t)far; 615 ksi->ksi_trap = fsr; 616 617 pcb->pcb_tf = tf; 618 619 return (1); 620 } 621 622 /* 623 * dab_buserr() handles the following data aborts: 624 * 625 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 626 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 627 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 628 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 629 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 630 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 631 * 632 * If pcb_onfault is set, flag the fault and return to the handler. 633 * If the fault occurred in user mode, give the process a SIGBUS. 634 * 635 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 636 * can be flagged as imprecise in the FSR. This causes a real headache 637 * since some of the machine state is lost. In this case, tf->tf_pc 638 * may not actually point to the offending instruction. In fact, if 639 * we've taken a double abort fault, it generally points somewhere near 640 * the top of "data_abort_entry" in exception.S. 641 * 642 * In all other cases, these data aborts are considered fatal. 643 */ 644 static int 645 dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, 646 ksiginfo_t *ksi) 647 { 648 struct pcb *pcb = lwp_getpcb(l); 649 650 #ifdef __XSCALE__ 651 if ((fsr & FAULT_IMPRECISE) != 0 && 652 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 653 /* 654 * Oops, an imprecise, double abort fault. We've lost the 655 * r14_abt/spsr_abt values corresponding to the original 656 * abort, and the spsr saved in the trapframe indicates 657 * ABT mode. 658 */ 659 tf->tf_spsr &= ~PSR_MODE; 660 661 /* 662 * We use a simple heuristic to determine if the double abort 663 * happened as a result of a kernel or user mode access. 664 * If the current trapframe is at the top of the kernel stack, 665 * the fault _must_ have come from user mode. 666 */ 667 if (tf != ((trapframe_t *)pcb->pcb_un.un_32.pcb32_sp) - 1) { 668 /* 669 * Kernel mode. We're either about to die a 670 * spectacular death, or pcb_onfault will come 671 * to our rescue. Either way, the current value 672 * of tf->tf_pc is irrelevant. 673 */ 674 tf->tf_spsr |= PSR_SVC32_MODE; 675 if (pcb->pcb_onfault == NULL) 676 printf("\nKernel mode double abort!\n"); 677 } else { 678 /* 679 * User mode. We've lost the program counter at the 680 * time of the fault (not that it was accurate anyway; 681 * it's not called an imprecise fault for nothing). 682 * About all we can do is copy r14_usr to tf_pc and 683 * hope for the best. The process is about to get a 684 * SIGBUS, so it's probably history anyway. 685 */ 686 tf->tf_spsr |= PSR_USR32_MODE; 687 tf->tf_pc = tf->tf_usr_lr; 688 #ifdef THUMB_CODE 689 tf->tf_spsr &= ~PSR_T_bit; 690 if (tf->tf_usr_lr & 1) 691 tf->tf_spsr |= PSR_T_bit; 692 #endif 693 } 694 } 695 696 /* FAR is invalid for imprecise exceptions */ 697 if ((fsr & FAULT_IMPRECISE) != 0) 698 far = 0; 699 #endif /* __XSCALE__ */ 700 701 if (pcb->pcb_onfault) { 702 KDASSERT(TRAP_USERMODE(tf) == 0); 703 tf->tf_r0 = EFAULT; 704 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 705 return (0); 706 } 707 708 /* See if the CPU state needs to be fixed up */ 709 (void) data_abort_fixup(tf, fsr, far, l); 710 711 /* 712 * At this point, if the fault happened in kernel mode, we're toast 713 */ 714 if (!TRAP_USERMODE(tf)) 715 dab_fatal(tf, fsr, far, l, NULL); 716 717 /* Deliver a bus error signal to the process */ 718 KSI_INIT_TRAP(ksi); 719 ksi->ksi_signo = SIGBUS; 720 ksi->ksi_code = BUS_ADRERR; 721 ksi->ksi_addr = (u_int32_t *)(intptr_t)far; 722 ksi->ksi_trap = fsr; 723 724 pcb->pcb_tf = tf; 725 726 return (1); 727 } 728 729 static inline int 730 prefetch_abort_fixup(trapframe_t *tf) 731 { 732 #ifdef CPU_ABORT_FIXUP_REQUIRED 733 int error; 734 735 /* Call the CPU specific prefetch abort fixup routine */ 736 error = cpu_prefetchabt_fixup(tf); 737 if (__predict_true(error != ABORT_FIXUP_FAILED)) 738 return (error); 739 740 /* 741 * Oops, couldn't fix up the instruction 742 */ 743 printf("%s: fixup for %s mode prefetch abort failed.\n", __func__, 744 TRAP_USERMODE(tf) ? "user" : "kernel"); 745 #ifdef THUMB_CODE 746 if (tf->tf_spsr & PSR_T_bit) { 747 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 748 tf->tf_pc, *((u_int16 *)(tf->tf_pc & ~1)), 749 *((u_int16 *)((tf->tf_pc + 2) & ~1))); 750 } 751 else 752 #endif 753 { 754 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 755 *((u_int *)tf->tf_pc)); 756 } 757 disassemble(tf->tf_pc); 758 759 /* Die now if this happened in kernel mode */ 760 if (!TRAP_USERMODE(tf)) 761 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 762 763 return (error); 764 #else 765 return (ABORT_FIXUP_OK); 766 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 767 } 768 769 /* 770 * void prefetch_abort_handler(trapframe_t *tf) 771 * 772 * Abort handler called when instruction execution occurs at 773 * a non existent or restricted (access permissions) memory page. 774 * If the address is invalid and we were in SVC mode then panic as 775 * the kernel should never prefetch abort. 776 * If the address is invalid and the page is mapped then the user process 777 * does no have read permission so send it a signal. 778 * Otherwise fault the page in and try again. 779 */ 780 void 781 prefetch_abort_handler(trapframe_t *tf) 782 { 783 struct lwp *l; 784 struct pcb *pcb; 785 struct vm_map *map; 786 vaddr_t fault_pc, va; 787 ksiginfo_t ksi; 788 int error, user; 789 790 UVMHIST_FUNC("prefetch_abort_handler"); UVMHIST_CALLED(maphist); 791 792 /* Update vmmeter statistics */ 793 curcpu()->ci_data.cpu_ntrap++; 794 795 l = curlwp; 796 pcb = lwp_getpcb(l); 797 798 if ((user = TRAP_USERMODE(tf)) != 0) 799 LWP_CACHE_CREDS(l, l->l_proc); 800 801 /* 802 * Enable IRQ's (disabled by the abort) This always comes 803 * from user mode so we know interrupts were not disabled. 804 * But we check anyway. 805 */ 806 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 807 if (__predict_true((tf->tf_spsr & I32_bit) != IF32_bits)) 808 restore_interrupts(tf->tf_spsr & IF32_bits); 809 810 /* See if the CPU state needs to be fixed up */ 811 switch (prefetch_abort_fixup(tf)) { 812 case ABORT_FIXUP_RETURN: 813 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 814 return; 815 case ABORT_FIXUP_FAILED: 816 /* Deliver a SIGILL to the process */ 817 KSI_INIT_TRAP(&ksi); 818 ksi.ksi_signo = SIGILL; 819 ksi.ksi_code = ILL_ILLOPC; 820 ksi.ksi_addr = (u_int32_t *)(intptr_t) tf->tf_pc; 821 pcb->pcb_tf = tf; 822 goto do_trapsignal; 823 default: 824 break; 825 } 826 827 /* Prefetch aborts cannot happen in kernel mode */ 828 if (__predict_false(!user)) 829 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 830 831 /* Get fault address */ 832 fault_pc = tf->tf_pc; 833 pcb->pcb_tf = tf; 834 UVMHIST_LOG(maphist, " (pc=0x%x, l=0x%x, tf=0x%x)", fault_pc, l, tf, 835 0); 836 837 /* Ok validate the address, can only execute in USER space */ 838 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 839 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 840 KSI_INIT_TRAP(&ksi); 841 ksi.ksi_signo = SIGSEGV; 842 ksi.ksi_code = SEGV_ACCERR; 843 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc; 844 ksi.ksi_trap = fault_pc; 845 goto do_trapsignal; 846 } 847 848 map = &l->l_proc->p_vmspace->vm_map; 849 va = trunc_page(fault_pc); 850 851 /* 852 * See if the pmap can handle this fault on its own... 853 */ 854 #ifdef DEBUG 855 last_fault_code = -1; 856 #endif 857 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) { 858 UVMHIST_LOG (maphist, " <- emulated", 0, 0, 0, 0); 859 goto out; 860 } 861 862 #ifdef DIAGNOSTIC 863 if (__predict_false(l->l_cpu->ci_intr_depth > 0)) { 864 printf("\nNon-emulated prefetch abort with intr_depth > 0\n"); 865 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 866 } 867 #endif 868 869 #ifdef KERN_SA 870 if (map != kernel_map && (l->l_flag & LW_SA)) { 871 l->l_savp->savp_faultaddr = fault_pc; 872 l->l_pflag |= LP_SA_PAGEFAULT; 873 } 874 #endif 875 876 KASSERT(pcb->pcb_onfault == NULL); 877 error = uvm_fault(map, va, VM_PROT_READ); 878 879 #ifdef KERN_SA 880 if (map != kernel_map) 881 l->l_pflag &= ~LP_SA_PAGEFAULT; 882 #endif 883 884 if (__predict_true(error == 0)) { 885 UVMHIST_LOG (maphist, " <- uvm", 0, 0, 0, 0); 886 goto out; 887 } 888 KSI_INIT_TRAP(&ksi); 889 890 UVMHIST_LOG (maphist, " <- fatal (%d)", error, 0, 0, 0); 891 if (error == ENOMEM) { 892 printf("UVM: pid %d (%s), uid %d killed: " 893 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 894 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 895 ksi.ksi_signo = SIGKILL; 896 } else 897 ksi.ksi_signo = SIGSEGV; 898 899 ksi.ksi_code = SEGV_MAPERR; 900 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc; 901 ksi.ksi_trap = fault_pc; 902 903 do_trapsignal: 904 call_trapsignal(l, &ksi); 905 906 out: 907 KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 908 userret(l); 909 } 910 911 /* 912 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 913 * If the read succeeds, the value is written to 'rptr' and zero is returned. 914 * Else, return EFAULT. 915 */ 916 int 917 badaddr_read(void *addr, size_t size, void *rptr) 918 { 919 extern int badaddr_read_1(const uint8_t *, uint8_t *); 920 extern int badaddr_read_2(const uint16_t *, uint16_t *); 921 extern int badaddr_read_4(const uint32_t *, uint32_t *); 922 union { 923 uint8_t v1; 924 uint16_t v2; 925 uint32_t v4; 926 } u; 927 struct pcb *curpcb_save; 928 int rv, s; 929 930 cpu_drain_writebuf(); 931 932 /* 933 * We might be called at interrupt time, so arrange to steal 934 * lwp0's PCB temporarily, if required, so that pcb_onfault 935 * handling works correctly. 936 */ 937 s = splhigh(); 938 if ((curpcb_save = curpcb) == NULL) 939 curpcb = lwp_getpcb(&lwp0); 940 941 /* Read from the test address. */ 942 switch (size) { 943 case sizeof(uint8_t): 944 rv = badaddr_read_1(addr, &u.v1); 945 if (rv == 0 && rptr) 946 *(uint8_t *) rptr = u.v1; 947 break; 948 949 case sizeof(uint16_t): 950 rv = badaddr_read_2(addr, &u.v2); 951 if (rv == 0 && rptr) 952 *(uint16_t *) rptr = u.v2; 953 break; 954 955 case sizeof(uint32_t): 956 rv = badaddr_read_4(addr, &u.v4); 957 if (rv == 0 && rptr) 958 *(uint32_t *) rptr = u.v4; 959 break; 960 961 default: 962 curpcb = curpcb_save; 963 panic("%s: invalid size (%lu)", __func__, (u_long)size); 964 } 965 966 /* Restore curpcb */ 967 curpcb = curpcb_save; 968 splx(s); 969 970 /* Return EFAULT if the address was invalid, else zero */ 971 return (rv); 972 } 973
Indexes created Thu Oct 02 14:10:14 GMT 2025