1 /* $NetBSD: fault.c,v 1.62 2006/07/23 22:06:04 ad 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 1.62 2006/07/23 22:06:04 ad Exp $"); 85 86 #include <sys/param.h> 87 #include <sys/systm.h> 88 #include <sys/proc.h> 89 #include <sys/savar.h> 90 #include <sys/user.h> 91 #include <sys/kernel.h> 92 #include <sys/kauth.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/cpuconf.h> 101 102 #include <machine/frame.h> 103 #include <arm/arm32/katelib.h> 104 #include <machine/cpu.h> 105 #include <machine/intr.h> 106 #if defined(DDB) || defined(KGDB) 107 #include <machine/db_machdep.h> 108 #ifdef KGDB 109 #include <sys/kgdb.h> 110 #endif 111 #if !defined(DDB) 112 #define kdb_trap kgdb_trap 113 #endif 114 #endif 115 116 #include <arch/arm/arm/disassem.h> 117 #include <arm/arm32/machdep.h> 118 119 extern char fusubailout[]; 120 121 #ifdef DEBUG 122 int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 123 #endif 124 125 #if defined(CPU_ARM3) || defined(CPU_ARM6) || \ 126 defined(CPU_ARM7) || defined(CPU_ARM7TDMI) 127 /* These CPUs may need data/prefetch abort fixups */ 128 #define CPU_ABORT_FIXUP_REQUIRED 129 #endif 130 131 struct data_abort { 132 int (*func)(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 133 const char *desc; 134 }; 135 136 static int dab_fatal(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 137 static int dab_align(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 138 static int dab_buserr(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 139 140 static const struct data_abort data_aborts[] = { 141 {dab_fatal, "Vector Exception"}, 142 {dab_align, "Alignment Fault 1"}, 143 {dab_fatal, "Terminal Exception"}, 144 {dab_align, "Alignment Fault 3"}, 145 {dab_buserr, "External Linefetch Abort (S)"}, 146 {NULL, "Translation Fault (S)"}, 147 {dab_buserr, "External Linefetch Abort (P)"}, 148 {NULL, "Translation Fault (P)"}, 149 {dab_buserr, "External Non-Linefetch Abort (S)"}, 150 {NULL, "Domain Fault (S)"}, 151 {dab_buserr, "External Non-Linefetch Abort (P)"}, 152 {NULL, "Domain Fault (P)"}, 153 {dab_buserr, "External Translation Abort (L1)"}, 154 {NULL, "Permission Fault (S)"}, 155 {dab_buserr, "External Translation Abort (L2)"}, 156 {NULL, "Permission Fault (P)"} 157 }; 158 159 /* Determine if a fault came from user mode */ 160 #define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE) 161 162 /* Determine if 'x' is a permission fault */ 163 #define IS_PERMISSION_FAULT(x) \ 164 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 165 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 166 167 #if 0 168 /* maybe one day we'll do emulations */ 169 #define TRAPSIGNAL(l,k) (*(l)->l_proc->p_emul->e_trapsignal)((l), (k)) 170 #else 171 #define TRAPSIGNAL(l,k) trapsignal((l), (k)) 172 #endif 173 174 static inline void 175 call_trapsignal(struct lwp *l, ksiginfo_t *ksi) 176 { 177 178 KERNEL_PROC_LOCK(l); 179 TRAPSIGNAL(l, ksi); 180 KERNEL_PROC_UNLOCK(l); 181 } 182 183 static inline int 184 data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l) 185 { 186 #ifdef CPU_ABORT_FIXUP_REQUIRED 187 int error; 188 189 /* Call the CPU specific data abort fixup routine */ 190 error = cpu_dataabt_fixup(tf); 191 if (__predict_true(error != ABORT_FIXUP_FAILED)) 192 return (error); 193 194 /* 195 * Oops, couldn't fix up the instruction 196 */ 197 printf("data_abort_fixup: fixup for %s mode data abort failed.\n", 198 TRAP_USERMODE(tf) ? "user" : "kernel"); 199 #ifdef THUMB_CODE 200 if (tf->tf_spsr & PSR_T_bit) { 201 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 202 tf->tf_pc, *((u_int16 *)(tf->tf_pc & ~1), 203 *((u_int16 *)((tf->tf_pc + 2) & ~1)); 204 } 205 else 206 #endif 207 { 208 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 209 *((u_int *)tf->tf_pc)); 210 } 211 disassemble(tf->tf_pc); 212 213 /* Die now if this happened in kernel mode */ 214 if (!TRAP_USERMODE(tf)) 215 dab_fatal(tf, fsr, far, l, NULL); 216 217 return (error); 218 #else 219 return (ABORT_FIXUP_OK); 220 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 221 } 222 223 void 224 data_abort_handler(trapframe_t *tf) 225 { 226 struct vm_map *map; 227 struct pcb *pcb; 228 struct lwp *l; 229 u_int user, far, fsr; 230 vm_prot_t ftype; 231 void *onfault; 232 vaddr_t va; 233 int error; 234 ksiginfo_t ksi; 235 236 UVMHIST_FUNC("data_abort_handler"); 237 238 /* Grab FAR/FSR before enabling interrupts */ 239 far = cpu_faultaddress(); 240 fsr = cpu_faultstatus(); 241 242 UVMHIST_CALLED(maphist); 243 /* Update vmmeter statistics */ 244 uvmexp.traps++; 245 246 /* Re-enable interrupts if they were enabled previously */ 247 if (__predict_true((tf->tf_spsr & I32_bit) == 0)) 248 enable_interrupts(I32_bit); 249 250 /* Get the current lwp structure or lwp0 if there is none */ 251 l = (curlwp != NULL) ? curlwp : &lwp0; 252 253 UVMHIST_LOG(maphist, " (pc=0x%x, l=0x%x, far=0x%x, fsr=0x%x)", 254 tf->tf_pc, l, far, fsr); 255 256 /* Data abort came from user mode? */ 257 if ((user = TRAP_USERMODE(tf)) != 0) 258 LWP_CACHE_CREDS(l, l->l_proc); 259 260 /* Grab the current pcb */ 261 pcb = &l->l_addr->u_pcb; 262 263 /* Invoke the appropriate handler, if necessary */ 264 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 265 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 266 l, &ksi)) 267 goto do_trapsignal; 268 goto out; 269 } 270 271 /* 272 * At this point, we're dealing with one of the following data aborts: 273 * 274 * FAULT_TRANS_S - Translation -- Section 275 * FAULT_TRANS_P - Translation -- Page 276 * FAULT_DOMAIN_S - Domain -- Section 277 * FAULT_DOMAIN_P - Domain -- Page 278 * FAULT_PERM_S - Permission -- Section 279 * FAULT_PERM_P - Permission -- Page 280 * 281 * These are the main virtual memory-related faults signalled by 282 * the MMU. 283 */ 284 285 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 286 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 287 tf->tf_r0 = EFAULT; 288 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 289 return; 290 } 291 292 if (user) 293 l->l_addr->u_pcb.pcb_tf = tf; 294 295 /* 296 * Make sure the Program Counter is sane. We could fall foul of 297 * someone executing Thumb code, in which case the PC might not 298 * be word-aligned. This would cause a kernel alignment fault 299 * further down if we have to decode the current instruction. 300 */ 301 #ifdef THUMB_CODE 302 /* 303 * XXX: It would be nice to be able to support Thumb in the kernel 304 * at some point. 305 */ 306 if (__predict_false(!user && (tf->tf_pc & 3) != 0)) { 307 printf("\ndata_abort_fault: Misaligned Kernel-mode " 308 "Program Counter\n"); 309 dab_fatal(tf, fsr, far, l, NULL); 310 } 311 #else 312 if (__predict_false((tf->tf_pc & 3) != 0)) { 313 if (user) { 314 /* 315 * Give the user an illegal instruction signal. 316 */ 317 /* Deliver a SIGILL to the process */ 318 KSI_INIT_TRAP(&ksi); 319 ksi.ksi_signo = SIGILL; 320 ksi.ksi_code = ILL_ILLOPC; 321 ksi.ksi_addr = (u_int32_t *)(intptr_t) far; 322 ksi.ksi_trap = fsr; 323 goto do_trapsignal; 324 } 325 326 /* 327 * The kernel never executes Thumb code. 328 */ 329 printf("\ndata_abort_fault: Misaligned Kernel-mode " 330 "Program Counter\n"); 331 dab_fatal(tf, fsr, far, l, NULL); 332 } 333 #endif 334 335 /* See if the CPU state needs to be fixed up */ 336 switch (data_abort_fixup(tf, fsr, far, l)) { 337 case ABORT_FIXUP_RETURN: 338 return; 339 case ABORT_FIXUP_FAILED: 340 /* Deliver a SIGILL to the process */ 341 KSI_INIT_TRAP(&ksi); 342 ksi.ksi_signo = SIGILL; 343 ksi.ksi_code = ILL_ILLOPC; 344 ksi.ksi_addr = (u_int32_t *)(intptr_t) far; 345 ksi.ksi_trap = fsr; 346 goto do_trapsignal; 347 default: 348 break; 349 } 350 351 va = trunc_page((vaddr_t)far); 352 353 /* 354 * It is only a kernel address space fault iff: 355 * 1. user == 0 and 356 * 2. pcb_onfault not set or 357 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 358 */ 359 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 360 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 361 __predict_true((pcb->pcb_onfault == NULL || 362 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 363 map = kernel_map; 364 365 /* Was the fault due to the FPE/IPKDB ? */ 366 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 367 KSI_INIT_TRAP(&ksi); 368 ksi.ksi_signo = SIGSEGV; 369 ksi.ksi_code = SEGV_ACCERR; 370 ksi.ksi_addr = (u_int32_t *)(intptr_t) far; 371 ksi.ksi_trap = fsr; 372 373 /* 374 * Force exit via userret() 375 * This is necessary as the FPE is an extension to 376 * userland that actually runs in a priveledged mode 377 * but uses USR mode permissions for its accesses. 378 */ 379 user = 1; 380 goto do_trapsignal; 381 } 382 } else { 383 map = &l->l_proc->p_vmspace->vm_map; 384 if (l->l_flag & L_SA) { 385 l->l_savp->savp_faultaddr = (vaddr_t)far; 386 l->l_flag |= L_SA_PAGEFAULT; 387 } 388 } 389 390 /* 391 * We need to know whether the page should be mapped 392 * as R or R/W. The MMU does not give us the info as 393 * to whether the fault was caused by a read or a write. 394 * 395 * However, we know that a permission fault can only be 396 * the result of a write to a read-only location, so 397 * we can deal with those quickly. 398 * 399 * Otherwise we need to disassemble the instruction 400 * responsible to determine if it was a write. 401 */ 402 if (IS_PERMISSION_FAULT(fsr)) 403 ftype = VM_PROT_WRITE; 404 else { 405 #ifdef THUMB_CODE 406 /* Fast track the ARM case. */ 407 if (__predict_false(tf->tf_spsr & PSR_T_bit)) { 408 u_int insn = fusword((void *)(tf->tf_pc & ~1)); 409 u_int insn_f8 = insn & 0xf800; 410 u_int insn_fe = insn & 0xfe00; 411 412 if (insn_f8 == 0x6000 || /* STR(1) */ 413 insn_f8 == 0x7000 || /* STRB(1) */ 414 insn_f8 == 0x8000 || /* STRH(1) */ 415 insn_f8 == 0x9000 || /* STR(3) */ 416 insn_f8 == 0xc000 || /* STM */ 417 insn_fe == 0x5000 || /* STR(2) */ 418 insn_fe == 0x5200 || /* STRH(2) */ 419 insn_fe == 0x5400) /* STRB(2) */ 420 ftype = VM_PROT_WRITE; 421 else 422 ftype = VM_PROT_READ; 423 } 424 else 425 #endif 426 { 427 u_int insn = ReadWord(tf->tf_pc); 428 429 if (((insn & 0x0c100000) == 0x04000000) || /* STR[B] */ 430 ((insn & 0x0e1000b0) == 0x000000b0) || /* STR[HD]*/ 431 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT*/ 432 ftype = VM_PROT_WRITE; 433 else if ((insn & 0x0fb00ff0) == 0x01000090)/* SWP */ 434 ftype = VM_PROT_READ | VM_PROT_WRITE; 435 else 436 ftype = VM_PROT_READ; 437 } 438 } 439 440 /* 441 * See if the fault is as a result of ref/mod emulation, 442 * or domain mismatch. 443 */ 444 #ifdef DEBUG 445 last_fault_code = fsr; 446 #endif 447 if (pmap_fault_fixup(map->pmap, va, ftype, user)) { 448 if (map != kernel_map) 449 l->l_flag &= ~L_SA_PAGEFAULT; 450 UVMHIST_LOG(maphist, " <- ref/mod emul", 0, 0, 0, 0); 451 goto out; 452 } 453 454 if (__predict_false(current_intr_depth > 0)) { 455 if (pcb->pcb_onfault) { 456 tf->tf_r0 = EINVAL; 457 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 458 return; 459 } 460 printf("\nNon-emulated page fault with intr_depth > 0\n"); 461 dab_fatal(tf, fsr, far, l, NULL); 462 } 463 464 onfault = pcb->pcb_onfault; 465 pcb->pcb_onfault = NULL; 466 error = uvm_fault(map, va, ftype); 467 pcb->pcb_onfault = onfault; 468 469 if (map != kernel_map) 470 l->l_flag &= ~L_SA_PAGEFAULT; 471 472 if (__predict_true(error == 0)) { 473 if (user) 474 uvm_grow(l->l_proc, va); /* Record any stack growth */ 475 UVMHIST_LOG(maphist, " <- uvm", 0, 0, 0, 0); 476 goto out; 477 } 478 479 if (user == 0) { 480 if (pcb->pcb_onfault) { 481 tf->tf_r0 = error; 482 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 483 return; 484 } 485 486 printf("\nuvm_fault(%p, %lx, %x) -> %x\n", map, va, ftype, 487 error); 488 dab_fatal(tf, fsr, far, l, NULL); 489 } 490 491 KSI_INIT_TRAP(&ksi); 492 493 if (error == ENOMEM) { 494 printf("UVM: pid %d (%s), uid %d killed: " 495 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 496 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 497 ksi.ksi_signo = SIGKILL; 498 } else 499 ksi.ksi_signo = SIGSEGV; 500 501 ksi.ksi_code = (error == EACCES) ? SEGV_ACCERR : SEGV_MAPERR; 502 ksi.ksi_addr = (u_int32_t *)(intptr_t) far; 503 ksi.ksi_trap = fsr; 504 UVMHIST_LOG(maphist, " <- erorr (%d)", error, 0, 0, 0); 505 506 do_trapsignal: 507 call_trapsignal(l, &ksi); 508 out: 509 /* If returning to user mode, make sure to invoke userret() */ 510 if (user) 511 userret(l); 512 } 513 514 /* 515 * dab_fatal() handles the following data aborts: 516 * 517 * FAULT_WRTBUF_0 - Vector Exception 518 * FAULT_WRTBUF_1 - Terminal Exception 519 * 520 * We should never see these on a properly functioning system. 521 * 522 * This function is also called by the other handlers if they 523 * detect a fatal problem. 524 * 525 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 526 */ 527 static int 528 dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 529 { 530 const char *mode; 531 532 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 533 534 if (l != NULL) { 535 printf("Fatal %s mode data abort: '%s'\n", mode, 536 data_aborts[fsr & FAULT_TYPE_MASK].desc); 537 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 538 if ((fsr & FAULT_IMPRECISE) == 0) 539 printf("%08x, ", far); 540 else 541 printf("Invalid, "); 542 printf("spsr=%08x\n", tf->tf_spsr); 543 } else { 544 printf("Fatal %s mode prefetch abort at 0x%08x\n", 545 mode, tf->tf_pc); 546 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 547 } 548 549 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 550 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 551 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 552 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 553 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 554 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 555 printf("r12=%08x, ", tf->tf_r12); 556 557 if (TRAP_USERMODE(tf)) 558 printf("usp=%08x, ulr=%08x", 559 tf->tf_usr_sp, tf->tf_usr_lr); 560 else 561 printf("ssp=%08x, slr=%08x", 562 tf->tf_svc_sp, tf->tf_svc_lr); 563 printf(", pc =%08x\n\n", tf->tf_pc); 564 565 #if defined(DDB) || defined(KGDB) 566 kdb_trap(T_FAULT, tf); 567 #endif 568 panic("Fatal abort"); 569 /*NOTREACHED*/ 570 } 571 572 /* 573 * dab_align() handles the following data aborts: 574 * 575 * FAULT_ALIGN_0 - Alignment fault 576 * FAULT_ALIGN_0 - Alignment fault 577 * 578 * These faults are fatal if they happen in kernel mode. Otherwise, we 579 * deliver a bus error to the process. 580 */ 581 static int 582 dab_align(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 583 { 584 585 /* Alignment faults are always fatal if they occur in kernel mode */ 586 if (!TRAP_USERMODE(tf)) 587 dab_fatal(tf, fsr, far, l, NULL); 588 589 /* pcb_onfault *must* be NULL at this point */ 590 KDASSERT(l->l_addr->u_pcb.pcb_onfault == NULL); 591 592 /* See if the CPU state needs to be fixed up */ 593 (void) data_abort_fixup(tf, fsr, far, l); 594 595 /* Deliver a bus error signal to the process */ 596 KSI_INIT_TRAP(ksi); 597 ksi->ksi_signo = SIGBUS; 598 ksi->ksi_code = BUS_ADRALN; 599 ksi->ksi_addr = (u_int32_t *)(intptr_t)far; 600 ksi->ksi_trap = fsr; 601 602 l->l_addr->u_pcb.pcb_tf = tf; 603 604 return (1); 605 } 606 607 /* 608 * dab_buserr() handles the following data aborts: 609 * 610 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 611 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 612 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 613 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 614 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 615 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 616 * 617 * If pcb_onfault is set, flag the fault and return to the handler. 618 * If the fault occurred in user mode, give the process a SIGBUS. 619 * 620 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 621 * can be flagged as imprecise in the FSR. This causes a real headache 622 * since some of the machine state is lost. In this case, tf->tf_pc 623 * may not actually point to the offending instruction. In fact, if 624 * we've taken a double abort fault, it generally points somewhere near 625 * the top of "data_abort_entry" in exception.S. 626 * 627 * In all other cases, these data aborts are considered fatal. 628 */ 629 static int 630 dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, 631 ksiginfo_t *ksi) 632 { 633 struct pcb *pcb = &l->l_addr->u_pcb; 634 635 #ifdef __XSCALE__ 636 if ((fsr & FAULT_IMPRECISE) != 0 && 637 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 638 /* 639 * Oops, an imprecise, double abort fault. We've lost the 640 * r14_abt/spsr_abt values corresponding to the original 641 * abort, and the spsr saved in the trapframe indicates 642 * ABT mode. 643 */ 644 tf->tf_spsr &= ~PSR_MODE; 645 646 /* 647 * We use a simple heuristic to determine if the double abort 648 * happened as a result of a kernel or user mode access. 649 * If the current trapframe is at the top of the kernel stack, 650 * the fault _must_ have come from user mode. 651 */ 652 if (tf != ((trapframe_t *)pcb->pcb_un.un_32.pcb32_sp) - 1) { 653 /* 654 * Kernel mode. We're either about to die a 655 * spectacular death, or pcb_onfault will come 656 * to our rescue. Either way, the current value 657 * of tf->tf_pc is irrelevant. 658 */ 659 tf->tf_spsr |= PSR_SVC32_MODE; 660 if (pcb->pcb_onfault == NULL) 661 printf("\nKernel mode double abort!\n"); 662 } else { 663 /* 664 * User mode. We've lost the program counter at the 665 * time of the fault (not that it was accurate anyway; 666 * it's not called an imprecise fault for nothing). 667 * About all we can do is copy r14_usr to tf_pc and 668 * hope for the best. The process is about to get a 669 * SIGBUS, so it's probably history anyway. 670 */ 671 tf->tf_spsr |= PSR_USR32_MODE; 672 tf->tf_pc = tf->tf_usr_lr; 673 #ifdef THUMB_CODE 674 tf->tf_spsr &= ~PSR_T_bit; 675 if (tf->tf_usr_lr & 1) 676 tf->tf_spsr |= PSR_T_bit; 677 #endif 678 } 679 } 680 681 /* FAR is invalid for imprecise exceptions */ 682 if ((fsr & FAULT_IMPRECISE) != 0) 683 far = 0; 684 #endif /* __XSCALE__ */ 685 686 if (pcb->pcb_onfault) { 687 KDASSERT(TRAP_USERMODE(tf) == 0); 688 tf->tf_r0 = EFAULT; 689 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 690 return (0); 691 } 692 693 /* See if the CPU state needs to be fixed up */ 694 (void) data_abort_fixup(tf, fsr, far, l); 695 696 /* 697 * At this point, if the fault happened in kernel mode, we're toast 698 */ 699 if (!TRAP_USERMODE(tf)) 700 dab_fatal(tf, fsr, far, l, NULL); 701 702 /* Deliver a bus error signal to the process */ 703 KSI_INIT_TRAP(ksi); 704 ksi->ksi_signo = SIGBUS; 705 ksi->ksi_code = BUS_ADRERR; 706 ksi->ksi_addr = (u_int32_t *)(intptr_t)far; 707 ksi->ksi_trap = fsr; 708 709 l->l_addr->u_pcb.pcb_tf = tf; 710 711 return (1); 712 } 713 714 static inline int 715 prefetch_abort_fixup(trapframe_t *tf) 716 { 717 #ifdef CPU_ABORT_FIXUP_REQUIRED 718 int error; 719 720 /* Call the CPU specific prefetch abort fixup routine */ 721 error = cpu_prefetchabt_fixup(tf); 722 if (__predict_true(error != ABORT_FIXUP_FAILED)) 723 return (error); 724 725 /* 726 * Oops, couldn't fix up the instruction 727 */ 728 printf( 729 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n", 730 TRAP_USERMODE(tf) ? "user" : "kernel"); 731 #ifdef THUMB_CODE 732 if (tf->tf_spsr & PSR_T_bit) { 733 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 734 tf->tf_pc, *((u_int16 *)(tf->tf_pc & ~1), 735 *((u_int16 *)((tf->tf_pc + 2) & ~1)); 736 } 737 else 738 #endif 739 { 740 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 741 *((u_int *)tf->tf_pc)); 742 } 743 disassemble(tf->tf_pc); 744 745 /* Die now if this happened in kernel mode */ 746 if (!TRAP_USERMODE(tf)) 747 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 748 749 return (error); 750 #else 751 return (ABORT_FIXUP_OK); 752 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 753 } 754 755 /* 756 * void prefetch_abort_handler(trapframe_t *tf) 757 * 758 * Abort handler called when instruction execution occurs at 759 * a non existent or restricted (access permissions) memory page. 760 * If the address is invalid and we were in SVC mode then panic as 761 * the kernel should never prefetch abort. 762 * If the address is invalid and the page is mapped then the user process 763 * does no have read permission so send it a signal. 764 * Otherwise fault the page in and try again. 765 */ 766 void 767 prefetch_abort_handler(trapframe_t *tf) 768 { 769 struct lwp *l; 770 struct vm_map *map; 771 vaddr_t fault_pc, va; 772 ksiginfo_t ksi; 773 int error, user; 774 775 UVMHIST_FUNC("prefetch_abort_handler"); UVMHIST_CALLED(maphist); 776 777 /* Update vmmeter statistics */ 778 uvmexp.traps++; 779 780 l = curlwp; 781 782 if ((user = TRAP_USERMODE(tf)) != 0) 783 LWP_CACHE_CREDS(l, l->l_proc); 784 785 /* 786 * Enable IRQ's (disabled by the abort) This always comes 787 * from user mode so we know interrupts were not disabled. 788 * But we check anyway. 789 */ 790 if (__predict_true((tf->tf_spsr & I32_bit) == 0)) 791 enable_interrupts(I32_bit); 792 793 /* See if the CPU state needs to be fixed up */ 794 switch (prefetch_abort_fixup(tf)) { 795 case ABORT_FIXUP_RETURN: 796 return; 797 case ABORT_FIXUP_FAILED: 798 /* Deliver a SIGILL to the process */ 799 KSI_INIT_TRAP(&ksi); 800 ksi.ksi_signo = SIGILL; 801 ksi.ksi_code = ILL_ILLOPC; 802 ksi.ksi_addr = (u_int32_t *)(intptr_t) tf->tf_pc; 803 l->l_addr->u_pcb.pcb_tf = tf; 804 goto do_trapsignal; 805 default: 806 break; 807 } 808 809 /* Prefetch aborts cannot happen in kernel mode */ 810 if (__predict_false(!user)) 811 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 812 813 /* Get fault address */ 814 fault_pc = tf->tf_pc; 815 l = curlwp; 816 l->l_addr->u_pcb.pcb_tf = tf; 817 UVMHIST_LOG(maphist, " (pc=0x%x, l=0x%x, tf=0x%x)", fault_pc, l, tf, 818 0); 819 820 /* Ok validate the address, can only execute in USER space */ 821 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 822 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 823 KSI_INIT_TRAP(&ksi); 824 ksi.ksi_signo = SIGSEGV; 825 ksi.ksi_code = SEGV_ACCERR; 826 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc; 827 ksi.ksi_trap = fault_pc; 828 goto do_trapsignal; 829 } 830 831 map = &l->l_proc->p_vmspace->vm_map; 832 va = trunc_page(fault_pc); 833 834 /* 835 * See if the pmap can handle this fault on its own... 836 */ 837 #ifdef DEBUG 838 last_fault_code = -1; 839 #endif 840 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) { 841 UVMHIST_LOG (maphist, " <- emulated", 0, 0, 0, 0); 842 goto out; 843 } 844 845 #ifdef DIAGNOSTIC 846 if (__predict_false(current_intr_depth > 0)) { 847 printf("\nNon-emulated prefetch abort with intr_depth > 0\n"); 848 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 849 } 850 #endif 851 if (map != kernel_map && l->l_flag & L_SA) { 852 l->l_savp->savp_faultaddr = fault_pc; 853 l->l_flag |= L_SA_PAGEFAULT; 854 } 855 856 error = uvm_fault(map, va, VM_PROT_READ); 857 858 if (map != kernel_map) 859 l->l_flag &= ~L_SA_PAGEFAULT; 860 861 if (__predict_true(error == 0)) { 862 UVMHIST_LOG (maphist, " <- uvm", 0, 0, 0, 0); 863 goto out; 864 } 865 KSI_INIT_TRAP(&ksi); 866 867 UVMHIST_LOG (maphist, " <- fatal (%d)", error, 0, 0, 0); 868 if (error == ENOMEM) { 869 printf("UVM: pid %d (%s), uid %d killed: " 870 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 871 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 872 ksi.ksi_signo = SIGKILL; 873 } else 874 ksi.ksi_signo = SIGSEGV; 875 876 ksi.ksi_code = SEGV_MAPERR; 877 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc; 878 ksi.ksi_trap = fault_pc; 879 880 do_trapsignal: 881 call_trapsignal(l, &ksi); 882 883 out: 884 userret(l); 885 } 886 887 /* 888 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 889 * If the read succeeds, the value is written to 'rptr' and zero is returned. 890 * Else, return EFAULT. 891 */ 892 int 893 badaddr_read(void *addr, size_t size, void *rptr) 894 { 895 extern int badaddr_read_1(const uint8_t *, uint8_t *); 896 extern int badaddr_read_2(const uint16_t *, uint16_t *); 897 extern int badaddr_read_4(const uint32_t *, uint32_t *); 898 union { 899 uint8_t v1; 900 uint16_t v2; 901 uint32_t v4; 902 } u; 903 struct pcb *curpcb_save; 904 int rv, s; 905 906 cpu_drain_writebuf(); 907 908 /* 909 * We might be called at interrupt time, so arrange to steal 910 * lwp0's PCB temporarily, if required, so that pcb_onfault 911 * handling works correctly. 912 */ 913 s = splhigh(); 914 if ((curpcb_save = curpcb) == NULL) 915 curpcb = &lwp0.l_addr->u_pcb; 916 917 /* Read from the test address. */ 918 switch (size) { 919 case sizeof(uint8_t): 920 rv = badaddr_read_1(addr, &u.v1); 921 if (rv == 0 && rptr) 922 *(uint8_t *) rptr = u.v1; 923 break; 924 925 case sizeof(uint16_t): 926 rv = badaddr_read_2(addr, &u.v2); 927 if (rv == 0 && rptr) 928 *(uint16_t *) rptr = u.v2; 929 break; 930 931 case sizeof(uint32_t): 932 rv = badaddr_read_4(addr, &u.v4); 933 if (rv == 0 && rptr) 934 *(uint32_t *) rptr = u.v4; 935 break; 936 937 default: 938 curpcb = curpcb_save; 939 panic("badaddr: invalid size (%lu)", (u_long) size); 940 } 941 942 /* Restore curpcb */ 943 curpcb = curpcb_save; 944 splx(s); 945 946 /* Return EFAULT if the address was invalid, else zero */ 947 return (rv); 948 } 949