fault.c revision 1.109.2.1
1 /* $NetBSD: fault.c,v 1.109.2.1 2020/02/29 20:18:17 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 1.109.2.1 2020/02/29 20:18:17 ad 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 <machine/pcb.h> 103 #if defined(DDB) || defined(KGDB) 104 #include <machine/db_machdep.h> 105 #ifdef KGDB 106 #include <sys/kgdb.h> 107 #endif 108 #if !defined(DDB) 109 #define kdb_trap kgdb_trap 110 #endif 111 #endif 112 113 #include <arch/arm/arm/disassem.h> 114 #include <arm/arm32/machdep.h> 115 116 #ifdef DEBUG 117 int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 118 #endif 119 120 #if defined(CPU_ARM6) || defined(CPU_ARM7) || defined(CPU_ARM7TDMI) 121 /* These CPUs may need data/prefetch abort fixups */ 122 #define CPU_ABORT_FIXUP_REQUIRED 123 #endif 124 125 struct data_abort { 126 int (*func)(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 127 const char *desc; 128 }; 129 130 static int dab_fatal(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 131 static int dab_align(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 132 static int dab_buserr(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 133 134 static const struct data_abort data_aborts[] = { 135 {dab_fatal, "Vector Exception"}, 136 {dab_align, "Alignment Fault 1"}, 137 {dab_fatal, "Terminal Exception"}, 138 {dab_align, "Alignment Fault 3"}, 139 {dab_buserr, "External Linefetch Abort (S)"}, 140 {NULL, "Translation Fault (S)"}, 141 {dab_buserr, "External Linefetch Abort (P)"}, 142 {NULL, "Translation Fault (P)"}, 143 {dab_buserr, "External Non-Linefetch Abort (S)"}, 144 {NULL, "Domain Fault (S)"}, 145 {dab_buserr, "External Non-Linefetch Abort (P)"}, 146 {NULL, "Domain Fault (P)"}, 147 {dab_buserr, "External Translation Abort (L1)"}, 148 {NULL, "Permission Fault (S)"}, 149 {dab_buserr, "External Translation Abort (L2)"}, 150 {NULL, "Permission Fault (P)"} 151 }; 152 153 /* Determine if 'x' is a permission fault */ 154 #define IS_PERMISSION_FAULT(x) \ 155 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 156 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 157 158 #if 0 159 /* maybe one day we'll do emulations */ 160 #define TRAPSIGNAL(l,k) (*(l)->l_proc->p_emul->e_trapsignal)((l), (k)) 161 #else 162 #define TRAPSIGNAL(l,k) trapsignal((l), (k)) 163 #endif 164 165 static inline void 166 call_trapsignal(struct lwp *l, const struct trapframe *tf, ksiginfo_t *ksi) 167 { 168 if (l->l_proc->p_pid == 1 || cpu_printfataltraps) { 169 printf("%d.%d(%s): trap: signo=%d code=%d addr=%p trap=%#x\n", 170 l->l_proc->p_pid, l->l_lid, l->l_proc->p_comm, 171 ksi->ksi_signo, ksi->ksi_code, ksi->ksi_addr, 172 ksi->ksi_trap); 173 printf("r0=%08x r1=%08x r2=%08x r3=%08x\n", 174 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 175 printf("r4=%08x r5=%08x r6=%08x r7=%08x\n", 176 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 177 printf("r8=%08x r9=%08x rA=%08x rB=%08x\n", 178 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 179 printf("ip=%08x sp=%08x lr=%08x pc=%08x spsr=%08x\n", 180 tf->tf_r12, tf->tf_usr_sp, tf->tf_usr_lr, tf->tf_pc, 181 tf->tf_spsr); 182 } 183 184 TRAPSIGNAL(l, ksi); 185 } 186 187 static inline int 188 data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l) 189 { 190 #ifdef CPU_ABORT_FIXUP_REQUIRED 191 int error; 192 193 /* Call the CPU specific data abort fixup routine */ 194 error = cpu_dataabt_fixup(tf); 195 if (__predict_true(error != ABORT_FIXUP_FAILED)) 196 return (error); 197 198 /* 199 * Oops, couldn't fix up the instruction 200 */ 201 printf("%s: fixup for %s mode data abort failed.\n", __func__, 202 TRAP_USERMODE(tf) ? "user" : "kernel"); 203 #ifdef THUMB_CODE 204 if (tf->tf_spsr & PSR_T_bit) { 205 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 206 tf->tf_pc, *((uint16 *)(tf->tf_pc & ~1)), 207 *((uint16 *)((tf->tf_pc + 2) & ~1))); 208 } 209 else 210 #endif 211 { 212 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 213 *((u_int *)tf->tf_pc)); 214 } 215 disassemble(tf->tf_pc); 216 217 /* Die now if this happened in kernel mode */ 218 if (!TRAP_USERMODE(tf)) 219 dab_fatal(tf, fsr, far, l, NULL); 220 221 return (error); 222 #else 223 return (ABORT_FIXUP_OK); 224 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 225 } 226 227 void 228 data_abort_handler(trapframe_t *tf) 229 { 230 struct vm_map *map; 231 struct lwp * const l = curlwp; 232 struct cpu_info * const ci = curcpu(); 233 u_int far, fsr; 234 vm_prot_t ftype; 235 void *onfault; 236 vaddr_t va; 237 int error; 238 ksiginfo_t ksi; 239 240 UVMHIST_FUNC(__func__); 241 UVMHIST_CALLED(maphist); 242 243 /* Grab FAR/FSR before enabling interrupts */ 244 far = cpu_faultaddress(); 245 fsr = cpu_faultstatus(); 246 247 /* Update vmmeter statistics */ 248 ci->ci_data.cpu_ntrap++; 249 250 /* Re-enable interrupts if they were enabled previously */ 251 KASSERT(!TRAP_USERMODE(tf) || VALID_R15_PSR(tf->tf_pc, tf->tf_spsr)); 252 #ifdef __NO_FIQ 253 if (__predict_true((tf->tf_spsr & I32_bit) != I32_bit)) 254 restore_interrupts(tf->tf_spsr & IF32_bits); 255 #else 256 if (__predict_true((tf->tf_spsr & IF32_bits) != IF32_bits)) 257 restore_interrupts(tf->tf_spsr & IF32_bits); 258 #endif 259 260 /* Get the current lwp structure */ 261 262 UVMHIST_LOG(maphist, " (l=%#jx, far=%#jx, fsr=%#jx", 263 (uintptr_t)l, far, fsr, 0); 264 UVMHIST_LOG(maphist, " tf=%#jx, pc=%#jx)", 265 (uintptr_t)tf, (uintptr_t)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 KASSERTMSG(!user || tf == lwp_trapframe(l), "tf %p vs %p", tf, 304 lwp_trapframe(l)); 305 306 /* 307 * Make sure the Program Counter is sane. We could fall foul of 308 * someone executing Thumb code, in which case the PC might not 309 * be word-aligned. This would cause a kernel alignment fault 310 * further down if we have to decode the current instruction. 311 */ 312 #ifdef THUMB_CODE 313 /* 314 * XXX: It would be nice to be able to support Thumb in the kernel 315 * at some point. 316 */ 317 if (__predict_false(!user && (tf->tf_pc & 3) != 0)) { 318 printf("\n%s: Misaligned Kernel-mode Program Counter\n", 319 __func__); 320 dab_fatal(tf, fsr, far, l, NULL); 321 } 322 #else 323 if (__predict_false((tf->tf_pc & 3) != 0)) { 324 if (user) { 325 /* 326 * Give the user an illegal instruction signal. 327 */ 328 /* Deliver a SIGILL to the process */ 329 KSI_INIT_TRAP(&ksi); 330 ksi.ksi_signo = SIGILL; 331 ksi.ksi_code = ILL_ILLOPC; 332 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 333 ksi.ksi_trap = fsr; 334 goto do_trapsignal; 335 } 336 337 /* 338 * The kernel never executes Thumb code. 339 */ 340 printf("\n%s: Misaligned Kernel-mode Program Counter\n", 341 __func__); 342 dab_fatal(tf, fsr, far, l, NULL); 343 } 344 #endif 345 346 /* See if the CPU state needs to be fixed up */ 347 switch (data_abort_fixup(tf, fsr, far, l)) { 348 case ABORT_FIXUP_RETURN: 349 return; 350 case ABORT_FIXUP_FAILED: 351 /* Deliver a SIGILL to the process */ 352 KSI_INIT_TRAP(&ksi); 353 ksi.ksi_signo = SIGILL; 354 ksi.ksi_code = ILL_ILLOPC; 355 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 356 ksi.ksi_trap = fsr; 357 goto do_trapsignal; 358 default: 359 break; 360 } 361 362 va = trunc_page((vaddr_t)far); 363 364 /* 365 * It is only a kernel address space fault iff: 366 * 1. user == 0 and 367 * 2. pcb_onfault not set or 368 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 369 */ 370 if (!user && (va >= VM_MIN_KERNEL_ADDRESS || 371 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 372 __predict_true((pcb->pcb_onfault == NULL || 373 (read_insn(tf->tf_pc, false) & 0x05200000) != 0x04200000))) { 374 map = kernel_map; 375 376 /* Was the fault due to the FPE ? */ 377 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 378 KSI_INIT_TRAP(&ksi); 379 ksi.ksi_signo = SIGSEGV; 380 ksi.ksi_code = SEGV_ACCERR; 381 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 382 ksi.ksi_trap = fsr; 383 384 /* 385 * Force exit via userret() 386 * This is necessary as the FPE is an extension to 387 * userland that actually runs in a priveledged mode 388 * but uses USR mode permissions for its accesses. 389 */ 390 user = true; 391 goto do_trapsignal; 392 } 393 } else { 394 map = &l->l_proc->p_vmspace->vm_map; 395 } 396 397 /* 398 * We need to know whether the page should be mapped as R or R/W. 399 * Before ARMv6, the MMU did not give us the info as to whether the 400 * fault was caused by a read or a write. 401 * 402 * However, we know that a permission fault can only be the result of 403 * a write to a read-only location, so we can deal with those quickly. 404 * 405 * Otherwise we need to disassemble the instruction responsible to 406 * determine if it was a write. 407 */ 408 if (CPU_IS_ARMV6_P() || CPU_IS_ARMV7_P()) { 409 ftype = (fsr & FAULT_WRITE) ? VM_PROT_WRITE : VM_PROT_READ; 410 } else 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 = read_thumb_insn(tf->tf_pc, user); 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 = read_insn(tf->tf_pc, user); 436 437 if (((insn & 0x0c100000) == 0x04000000) || /* STR[B] */ 438 ((insn & 0x0e1000b0) == 0x000000b0) || /* STR[HD]*/ 439 ((insn & 0x0a100000) == 0x08000000) || /* STM/CDT*/ 440 ((insn & 0x0f9000f0) == 0x01800090)) /* STREX[BDH] */ 441 ftype = VM_PROT_WRITE; 442 else if ((insn & 0x0fb00ff0) == 0x01000090)/* SWP */ 443 ftype = VM_PROT_READ | VM_PROT_WRITE; 444 else 445 ftype = VM_PROT_READ; 446 } 447 } 448 449 /* 450 * See if the fault is as a result of ref/mod emulation, 451 * or domain mismatch. 452 */ 453 #ifdef DEBUG 454 last_fault_code = fsr; 455 #endif 456 if (pmap_fault_fixup(map->pmap, va, ftype, user)) { 457 UVMHIST_LOG(maphist, " <- ref/mod emul", 0, 0, 0, 0); 458 goto out; 459 } 460 461 if (__predict_false(curcpu()->ci_intr_depth > 0)) { 462 if (pcb->pcb_onfault) { 463 tf->tf_r0 = EINVAL; 464 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 465 return; 466 } 467 printf("\nNon-emulated page fault with intr_depth > 0\n"); 468 dab_fatal(tf, fsr, far, l, NULL); 469 } 470 471 onfault = pcb->pcb_onfault; 472 pcb->pcb_onfault = NULL; 473 error = uvm_fault(map, va, ftype); 474 pcb->pcb_onfault = onfault; 475 476 if (__predict_true(error == 0)) { 477 if (user) 478 uvm_grow(l->l_proc, va); /* Record any stack growth */ 479 UVMHIST_LOG(maphist, " <- uvm", 0, 0, 0, 0); 480 goto out; 481 } 482 483 if (user == 0) { 484 if (pcb->pcb_onfault) { 485 tf->tf_r0 = error; 486 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 487 return; 488 } 489 490 printf("\nuvm_fault(%p, %lx, %x) -> %x\n", map, va, ftype, 491 error); 492 dab_fatal(tf, fsr, far, l, NULL); 493 } 494 495 KSI_INIT_TRAP(&ksi); 496 497 switch (error) { 498 case ENOMEM: 499 printf("UVM: pid %d (%s), uid %d killed: " 500 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 501 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 502 ksi.ksi_signo = SIGKILL; 503 break; 504 case EACCES: 505 ksi.ksi_signo = SIGSEGV; 506 ksi.ksi_code = SEGV_ACCERR; 507 break; 508 case EINVAL: 509 ksi.ksi_signo = SIGBUS; 510 ksi.ksi_code = BUS_ADRERR; 511 break; 512 default: 513 ksi.ksi_signo = SIGSEGV; 514 ksi.ksi_code = SEGV_MAPERR; 515 break; 516 } 517 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 518 ksi.ksi_trap = fsr; 519 UVMHIST_LOG(maphist, " <- error (%jd)", error, 0, 0, 0); 520 521 do_trapsignal: 522 call_trapsignal(l, tf, &ksi); 523 out: 524 /* If returning to user mode, make sure to invoke userret() */ 525 if (user) 526 userret(l); 527 } 528 529 /* 530 * dab_fatal() handles the following data aborts: 531 * 532 * FAULT_WRTBUF_0 - Vector Exception 533 * FAULT_WRTBUF_1 - Terminal Exception 534 * 535 * We should never see these on a properly functioning system. 536 * 537 * This function is also called by the other handlers if they 538 * detect a fatal problem. 539 * 540 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 541 */ 542 static int 543 dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 544 { 545 const char * const mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 546 547 if (l != NULL) { 548 printf("Fatal %s mode data abort: '%s'\n", mode, 549 data_aborts[fsr & FAULT_TYPE_MASK].desc); 550 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 551 if ((fsr & FAULT_IMPRECISE) == 0) 552 printf("%08x, ", far); 553 else 554 printf("Invalid, "); 555 printf("spsr=%08x\n", tf->tf_spsr); 556 } else { 557 printf("Fatal %s mode prefetch abort at 0x%08x\n", 558 mode, tf->tf_pc); 559 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 560 } 561 562 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 563 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 564 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 565 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 566 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 567 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 568 printf("r12=%08x, ", tf->tf_r12); 569 570 if (TRAP_USERMODE(tf)) 571 printf("usp=%08x, ulr=%08x", 572 tf->tf_usr_sp, tf->tf_usr_lr); 573 else 574 printf("ssp=%08x, slr=%08x", 575 tf->tf_svc_sp, tf->tf_svc_lr); 576 printf(", pc =%08x\n\n", tf->tf_pc); 577 578 #if defined(DDB) || defined(KGDB) 579 kdb_trap(T_FAULT, tf); 580 #endif 581 panic("Fatal abort"); 582 /*NOTREACHED*/ 583 } 584 585 /* 586 * dab_align() handles the following data aborts: 587 * 588 * FAULT_ALIGN_0 - Alignment fault 589 * FAULT_ALIGN_0 - Alignment fault 590 * 591 * These faults are fatal if they happen in kernel mode. Otherwise, we 592 * deliver a bus error to the process. 593 */ 594 static int 595 dab_align(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 596 { 597 /* Alignment faults are always fatal if they occur in kernel mode */ 598 if (!TRAP_USERMODE(tf)) 599 dab_fatal(tf, fsr, far, l, NULL); 600 601 /* pcb_onfault *must* be NULL at this point */ 602 KDASSERT(((struct pcb *)lwp_getpcb(l))->pcb_onfault == NULL); 603 604 /* See if the CPU state needs to be fixed up */ 605 (void) data_abort_fixup(tf, fsr, far, l); 606 607 /* Deliver a bus error signal to the process */ 608 KSI_INIT_TRAP(ksi); 609 ksi->ksi_signo = SIGBUS; 610 ksi->ksi_code = BUS_ADRALN; 611 ksi->ksi_addr = (uint32_t *)(intptr_t)far; 612 ksi->ksi_trap = fsr; 613 614 KASSERTMSG(tf == lwp_trapframe(l), "tf %p vs %p", tf, lwp_trapframe(l)); 615 616 return (1); 617 } 618 619 /* 620 * dab_buserr() handles the following data aborts: 621 * 622 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 623 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 624 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 625 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 626 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 627 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 628 * 629 * If pcb_onfault is set, flag the fault and return to the handler. 630 * If the fault occurred in user mode, give the process a SIGBUS. 631 * 632 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 633 * can be flagged as imprecise in the FSR. This causes a real headache 634 * since some of the machine state is lost. In this case, tf->tf_pc 635 * may not actually point to the offending instruction. In fact, if 636 * we've taken a double abort fault, it generally points somewhere near 637 * the top of "data_abort_entry" in exception.S. 638 * 639 * In all other cases, these data aborts are considered fatal. 640 */ 641 static int 642 dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, 643 ksiginfo_t *ksi) 644 { 645 struct pcb *pcb = lwp_getpcb(l); 646 647 #ifdef __XSCALE__ 648 if ((fsr & FAULT_IMPRECISE) != 0 && 649 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 650 /* 651 * Oops, an imprecise, double abort fault. We've lost the 652 * r14_abt/spsr_abt values corresponding to the original 653 * abort, and the spsr saved in the trapframe indicates 654 * ABT mode. 655 */ 656 tf->tf_spsr &= ~PSR_MODE; 657 658 /* 659 * We use a simple heuristic to determine if the double abort 660 * happened as a result of a kernel or user mode access. 661 * If the current trapframe is at the top of the kernel stack, 662 * the fault _must_ have come from user mode. 663 */ 664 if (tf != ((trapframe_t *)pcb->pcb_ksp) - 1) { 665 /* 666 * Kernel mode. We're either about to die a 667 * spectacular death, or pcb_onfault will come 668 * to our rescue. Either way, the current value 669 * of tf->tf_pc is irrelevant. 670 */ 671 tf->tf_spsr |= PSR_SVC32_MODE; 672 if (pcb->pcb_onfault == NULL) 673 printf("\nKernel mode double abort!\n"); 674 } else { 675 /* 676 * User mode. We've lost the program counter at the 677 * time of the fault (not that it was accurate anyway; 678 * it's not called an imprecise fault for nothing). 679 * About all we can do is copy r14_usr to tf_pc and 680 * hope for the best. The process is about to get a 681 * SIGBUS, so it's probably history anyway. 682 */ 683 tf->tf_spsr |= PSR_USR32_MODE; 684 tf->tf_pc = tf->tf_usr_lr; 685 #ifdef THUMB_CODE 686 tf->tf_spsr &= ~PSR_T_bit; 687 if (tf->tf_usr_lr & 1) 688 tf->tf_spsr |= PSR_T_bit; 689 #endif 690 } 691 } 692 693 /* FAR is invalid for imprecise exceptions */ 694 if ((fsr & FAULT_IMPRECISE) != 0) 695 far = 0; 696 #endif /* __XSCALE__ */ 697 698 if (pcb->pcb_onfault) { 699 KDASSERT(TRAP_USERMODE(tf) == 0); 700 tf->tf_r0 = EFAULT; 701 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 702 return (0); 703 } 704 705 /* See if the CPU state needs to be fixed up */ 706 (void) data_abort_fixup(tf, fsr, far, l); 707 708 /* 709 * At this point, if the fault happened in kernel mode, we're toast 710 */ 711 if (!TRAP_USERMODE(tf)) 712 dab_fatal(tf, fsr, far, l, NULL); 713 714 /* Deliver a bus error signal to the process */ 715 KSI_INIT_TRAP(ksi); 716 ksi->ksi_signo = SIGBUS; 717 ksi->ksi_code = BUS_ADRERR; 718 ksi->ksi_addr = (uint32_t *)(intptr_t)far; 719 ksi->ksi_trap = fsr; 720 721 KASSERTMSG(tf == lwp_trapframe(l), "tf %p vs %p", tf, lwp_trapframe(l)); 722 723 return (1); 724 } 725 726 static inline int 727 prefetch_abort_fixup(trapframe_t *tf) 728 { 729 #ifdef CPU_ABORT_FIXUP_REQUIRED 730 int error; 731 732 /* Call the CPU specific prefetch abort fixup routine */ 733 error = cpu_prefetchabt_fixup(tf); 734 if (__predict_true(error != ABORT_FIXUP_FAILED)) 735 return (error); 736 737 /* 738 * Oops, couldn't fix up the instruction 739 */ 740 printf("%s: fixup for %s mode prefetch abort failed.\n", __func__, 741 TRAP_USERMODE(tf) ? "user" : "kernel"); 742 #ifdef THUMB_CODE 743 if (tf->tf_spsr & PSR_T_bit) { 744 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 745 tf->tf_pc, *((uint16 *)(tf->tf_pc & ~1)), 746 *((uint16 *)((tf->tf_pc + 2) & ~1))); 747 } 748 else 749 #endif 750 { 751 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 752 *((u_int *)tf->tf_pc)); 753 } 754 disassemble(tf->tf_pc); 755 756 /* Die now if this happened in kernel mode */ 757 if (!TRAP_USERMODE(tf)) 758 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 759 760 return (error); 761 #else 762 return (ABORT_FIXUP_OK); 763 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 764 } 765 766 /* 767 * void prefetch_abort_handler(trapframe_t *tf) 768 * 769 * Abort handler called when instruction execution occurs at 770 * a non existent or restricted (access permissions) memory page. 771 * If the address is invalid and we were in SVC mode then panic as 772 * the kernel should never prefetch abort. 773 * If the address is invalid and the page is mapped then the user process 774 * does no have read permission so send it a signal. 775 * Otherwise fault the page in and try again. 776 */ 777 void 778 prefetch_abort_handler(trapframe_t *tf) 779 { 780 struct lwp *l; 781 struct pcb *pcb __diagused; 782 struct vm_map *map; 783 vaddr_t fault_pc, va; 784 ksiginfo_t ksi; 785 int error, user; 786 787 UVMHIST_FUNC(__func__); 788 UVMHIST_CALLED(maphist); 789 790 /* Update vmmeter statistics */ 791 curcpu()->ci_data.cpu_ntrap++; 792 793 l = curlwp; 794 pcb = lwp_getpcb(l); 795 796 if ((user = TRAP_USERMODE(tf)) != 0) 797 LWP_CACHE_CREDS(l, l->l_proc); 798 799 /* 800 * Enable IRQ's (disabled by the abort) This always comes 801 * from user mode so we know interrupts were not disabled. 802 * But we check anyway. 803 */ 804 KASSERT(!TRAP_USERMODE(tf) || VALID_R15_PSR(tf->tf_pc, tf->tf_spsr)); 805 #ifdef __NO_FIQ 806 if (__predict_true((tf->tf_spsr & I32_bit) != I32_bit)) 807 restore_interrupts(tf->tf_spsr & IF32_bits); 808 #else 809 if (__predict_true((tf->tf_spsr & IF32_bits) != IF32_bits)) 810 restore_interrupts(tf->tf_spsr & IF32_bits); 811 #endif 812 813 /* See if the CPU state needs to be fixed up */ 814 switch (prefetch_abort_fixup(tf)) { 815 case ABORT_FIXUP_RETURN: 816 KASSERT(!TRAP_USERMODE(tf) || VALID_R15_PSR(tf->tf_pc, tf->tf_spsr)); 817 return; 818 case ABORT_FIXUP_FAILED: 819 /* Deliver a SIGILL to the process */ 820 KSI_INIT_TRAP(&ksi); 821 ksi.ksi_signo = SIGILL; 822 ksi.ksi_code = ILL_ILLOPC; 823 ksi.ksi_addr = (uint32_t *)(intptr_t) tf->tf_pc; 824 KASSERTMSG(tf == lwp_trapframe(l), "tf %p vs %p", tf, 825 lwp_trapframe(l)); 826 goto do_trapsignal; 827 default: 828 break; 829 } 830 831 /* Prefetch aborts cannot happen in kernel mode */ 832 if (__predict_false(!user)) 833 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 834 835 /* Get fault address */ 836 fault_pc = tf->tf_pc; 837 KASSERTMSG(tf == lwp_trapframe(l), "tf %p vs %p", tf, lwp_trapframe(l)); 838 UVMHIST_LOG(maphist, " (pc=%#jx, l=%#jx, tf=%#jx)", 839 fault_pc, (uintptr_t)l, (uintptr_t)tf, 0); 840 841 #ifdef THUMB_CODE 842 recheck: 843 #endif 844 /* Ok validate the address, can only execute in USER space */ 845 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 846 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 847 KSI_INIT_TRAP(&ksi); 848 ksi.ksi_signo = SIGSEGV; 849 ksi.ksi_code = SEGV_ACCERR; 850 ksi.ksi_addr = (uint32_t *)(intptr_t) fault_pc; 851 ksi.ksi_trap = fault_pc; 852 goto do_trapsignal; 853 } 854 855 map = &l->l_proc->p_vmspace->vm_map; 856 va = trunc_page(fault_pc); 857 858 /* 859 * See if the pmap can handle this fault on its own... 860 */ 861 #ifdef DEBUG 862 last_fault_code = -1; 863 #endif 864 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ|VM_PROT_EXECUTE, 1)) { 865 UVMHIST_LOG (maphist, " <- emulated", 0, 0, 0, 0); 866 goto out; 867 } 868 869 #ifdef DIAGNOSTIC 870 if (__predict_false(curcpu()->ci_intr_depth > 0)) { 871 printf("\nNon-emulated prefetch abort with intr_depth > 0\n"); 872 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 873 } 874 #endif 875 876 KASSERT(pcb->pcb_onfault == NULL); 877 error = uvm_fault(map, va, VM_PROT_READ|VM_PROT_EXECUTE); 878 879 if (__predict_true(error == 0)) { 880 UVMHIST_LOG (maphist, " <- uvm", 0, 0, 0, 0); 881 goto out; 882 } 883 KSI_INIT_TRAP(&ksi); 884 885 UVMHIST_LOG (maphist, " <- fatal (%jd)", error, 0, 0, 0); 886 887 if (error == ENOMEM) { 888 printf("UVM: pid %d (%s), uid %d killed: " 889 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 890 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 891 ksi.ksi_signo = SIGKILL; 892 } else 893 ksi.ksi_signo = SIGSEGV; 894 895 ksi.ksi_code = SEGV_MAPERR; 896 ksi.ksi_addr = (uint32_t *)(intptr_t) fault_pc; 897 ksi.ksi_trap = fault_pc; 898 899 do_trapsignal: 900 call_trapsignal(l, tf, &ksi); 901 902 out: 903 904 #ifdef THUMB_CODE 905 #define THUMB_32BIT(hi) (((hi) & 0xe000) == 0xe000 && ((hi) & 0x1800)) 906 /* thumb-32 instruction was located on page boundary? */ 907 if ((tf->tf_spsr & PSR_T_bit) && 908 ((fault_pc & PAGE_MASK) == (PAGE_SIZE - THUMB_INSN_SIZE)) && 909 THUMB_32BIT(*(uint16_t *)tf->tf_pc)) { 910 fault_pc = tf->tf_pc + THUMB_INSN_SIZE; 911 goto recheck; 912 } 913 #endif /* THUMB_CODE */ 914 915 KASSERT(!TRAP_USERMODE(tf) || VALID_R15_PSR(tf->tf_pc, tf->tf_spsr)); 916 userret(l); 917 } 918 919 /* 920 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 921 * If the read succeeds, the value is written to 'rptr' and zero is returned. 922 * Else, return EFAULT. 923 */ 924 int 925 badaddr_read(void *addr, size_t size, void *rptr) 926 { 927 extern int badaddr_read_1(const uint8_t *, uint8_t *); 928 extern int badaddr_read_2(const uint16_t *, uint16_t *); 929 extern int badaddr_read_4(const uint32_t *, uint32_t *); 930 union { 931 uint8_t v1; 932 uint16_t v2; 933 uint32_t v4; 934 } u; 935 int rv, s; 936 937 cpu_drain_writebuf(); 938 939 s = splhigh(); 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 panic("%s: invalid size (%zu)", __func__, size); 963 } 964 965 splx(s); 966 967 /* Return EFAULT if the address was invalid, else zero */ 968 return (rv); 969 } 970
Indexes created Thu Oct 02 14:10:14 GMT 2025