1 /* $NetBSD: fault.c,v 1.119 2024/02/02 22:00:32 andvar 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_multiprocessor.h" 83 84 #include <sys/types.h> 85 __KERNEL_RCSID(0, "$NetBSD: fault.c,v 1.119 2024/02/02 22:00:32 andvar Exp $"); 86 87 #include <sys/param.h> 88 89 #include <sys/cpu.h> 90 #include <sys/intr.h> 91 #include <sys/kauth.h> 92 #include <sys/kernel.h> 93 #include <sys/proc.h> 94 #include <sys/systm.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/locore.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 #if defined(DEBUG) && !defined(MULTIPROCESSOR) 119 int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 120 #endif 121 122 #if defined(CPU_ARM6) || defined(CPU_ARM7) || defined(CPU_ARM7TDMI) 123 /* These CPUs may need data/prefetch abort fixups */ 124 #define CPU_ABORT_FIXUP_REQUIRED 125 #endif 126 127 struct data_abort { 128 int (*func)(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 129 const char *desc; 130 }; 131 132 static int dab_fatal(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 133 static int dab_align(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 134 static int dab_buserr(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *); 135 136 static const struct data_abort data_aborts[] = { 137 {dab_fatal, "Vector Exception"}, 138 {dab_align, "Alignment Fault 1"}, 139 {dab_fatal, "Terminal Exception"}, 140 {dab_align, "Alignment Fault 3"}, 141 {dab_buserr, "External Linefetch Abort (S)"}, 142 {NULL, "Translation Fault (S)"}, 143 {dab_buserr, "External Linefetch Abort (P)"}, 144 {NULL, "Translation Fault (P)"}, 145 {dab_buserr, "External Non-Linefetch Abort (S)"}, 146 {NULL, "Domain Fault (S)"}, 147 {dab_buserr, "External Non-Linefetch Abort (P)"}, 148 {NULL, "Domain Fault (P)"}, 149 {dab_buserr, "External Translation Abort (L1)"}, 150 {NULL, "Permission Fault (S)"}, 151 {dab_buserr, "External Translation Abort (L2)"}, 152 {NULL, "Permission Fault (P)"} 153 }; 154 155 /* Determine if 'x' is a permission fault */ 156 #define IS_PERMISSION_FAULT(x) \ 157 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 158 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 159 160 #if 0 161 /* maybe one day we'll do emulations */ 162 #define TRAPSIGNAL(l,k) (*(l)->l_proc->p_emul->e_trapsignal)((l), (k)) 163 #else 164 #define TRAPSIGNAL(l,k) trapsignal((l), (k)) 165 #endif 166 167 static inline void 168 call_trapsignal(struct lwp *l, const struct trapframe *tf, ksiginfo_t *ksi) 169 { 170 if (l->l_proc->p_pid == 1 || cpu_printfataltraps) { 171 printf("%d.%d(%s): trap: signo=%d code=%d addr=%p trap=%#x\n", 172 l->l_proc->p_pid, l->l_lid, l->l_proc->p_comm, 173 ksi->ksi_signo, ksi->ksi_code, ksi->ksi_addr, 174 ksi->ksi_trap); 175 printf("r0=%08x r1=%08x r2=%08x r3=%08x\n", 176 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 177 printf("r4=%08x r5=%08x r6=%08x r7=%08x\n", 178 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 179 printf("r8=%08x r9=%08x rA=%08x rB=%08x\n", 180 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 181 printf("ip=%08x sp=%08x lr=%08x pc=%08x spsr=%08x\n", 182 tf->tf_r12, tf->tf_usr_sp, tf->tf_usr_lr, tf->tf_pc, 183 tf->tf_spsr); 184 } 185 186 TRAPSIGNAL(l, ksi); 187 } 188 189 static inline int 190 data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l) 191 { 192 #ifdef CPU_ABORT_FIXUP_REQUIRED 193 int error; 194 195 /* Call the CPU specific data abort fixup routine */ 196 error = cpu_dataabt_fixup(tf); 197 if (__predict_true(error != ABORT_FIXUP_FAILED)) 198 return error; 199 200 /* 201 * Oops, couldn't fix up the instruction 202 */ 203 printf("%s: fixup for %s mode data abort failed.\n", __func__, 204 TRAP_USERMODE(tf) ? "user" : "kernel"); 205 #ifdef THUMB_CODE 206 if (tf->tf_spsr & PSR_T_bit) { 207 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 208 tf->tf_pc, *((uint16 *)(tf->tf_pc & ~1)), 209 *((uint16 *)((tf->tf_pc + 2) & ~1))); 210 } 211 else 212 #endif 213 { 214 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 215 *((u_int *)tf->tf_pc)); 216 } 217 disassemble(tf->tf_pc); 218 219 /* Die now if this happened in kernel mode */ 220 if (!TRAP_USERMODE(tf)) 221 dab_fatal(tf, fsr, far, l, NULL); 222 223 return error; 224 #else 225 return ABORT_FIXUP_OK; 226 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 227 } 228 229 void 230 data_abort_handler(trapframe_t *tf) 231 { 232 struct vm_map *map; 233 struct lwp * const l = curlwp; 234 struct cpu_info * const ci = curcpu(); 235 u_int far, fsr; 236 vm_prot_t ftype; 237 void *onfault; 238 vaddr_t va; 239 int error; 240 ksiginfo_t ksi; 241 242 UVMHIST_FUNC(__func__); 243 UVMHIST_CALLED(maphist); 244 245 /* Grab FAR/FSR before enabling interrupts */ 246 far = cpu_faultaddress(); 247 fsr = cpu_faultstatus(); 248 249 /* Update vmmeter statistics */ 250 ci->ci_data.cpu_ntrap++; 251 252 /* Re-enable interrupts if they were enabled previously */ 253 KASSERT(!TRAP_USERMODE(tf) || VALID_PSR(tf->tf_spsr)); 254 #ifdef __NO_FIQ 255 if (__predict_true((tf->tf_spsr & I32_bit) != I32_bit)) 256 restore_interrupts(tf->tf_spsr & IF32_bits); 257 #else 258 if (__predict_true((tf->tf_spsr & IF32_bits) != IF32_bits)) 259 restore_interrupts(tf->tf_spsr & IF32_bits); 260 #endif 261 262 /* Get the current lwp structure */ 263 264 UVMHIST_LOG(maphist, " (l=%#jx, far=%#jx, fsr=%#jx", 265 (uintptr_t)l, far, fsr, 0); 266 UVMHIST_LOG(maphist, " tf=%#jx, pc=%#jx)", 267 (uintptr_t)tf, (uintptr_t)tf->tf_pc, 0, 0); 268 269 /* Data abort came from user mode? */ 270 bool user = (TRAP_USERMODE(tf) != 0); 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 privileged 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 #if defined(DEBUG) && !defined(MULTIPROCESSOR) 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 #ifdef PMAP_FAULTINFO 472 struct pcb_faultinfo * const pfi = &pcb->pcb_faultinfo; 473 struct proc * const p = curproc; 474 475 if (p->p_pid == pfi->pfi_lastpid && va == pfi->pfi_faultaddr) { 476 if (++pfi->pfi_repeats > 4) { 477 tlb_asid_t asid = tlb_get_asid(); 478 pt_entry_t *ptep = pfi->pfi_faultptep; 479 480 printf("%s: fault #%u (%x/%s) for %#" PRIxVADDR 481 "(%#x) at pc %#" PRIxREGISTER " curpid=%u/%u " 482 "ptep@%p=%#" PRIxPTE ")\n", __func__, 483 pfi->pfi_repeats, fsr & FAULT_TYPE_MASK, 484 data_aborts[fsr & FAULT_TYPE_MASK].desc, va, 485 far, tf->tf_pc, map->pmap->pm_pai[0].pai_asid, 486 asid, ptep, ptep ? *ptep : 0); 487 cpu_Debugger(); 488 } 489 } else { 490 pfi->pfi_lastpid = p->p_pid; 491 pfi->pfi_faultaddr = va; 492 pfi->pfi_repeats = 0; 493 pfi->pfi_faultptep = NULL; 494 pfi->pfi_faulttype = fsr & FAULT_TYPE_MASK; 495 } 496 #endif /* PMAP_FAULTINFO */ 497 498 onfault = pcb->pcb_onfault; 499 pcb->pcb_onfault = NULL; 500 error = uvm_fault(map, va, ftype); 501 pcb->pcb_onfault = onfault; 502 503 if (__predict_true(error == 0)) { 504 if (user) 505 uvm_grow(l->l_proc, va); /* Record any stack growth */ 506 UVMHIST_LOG(maphist, " <- uvm", 0, 0, 0, 0); 507 goto out; 508 } 509 510 if (user == 0) { 511 if (pcb->pcb_onfault) { 512 tf->tf_r0 = error; 513 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 514 return; 515 } 516 517 printf("\nuvm_fault(%p, %lx, %x) -> %x\n", map, va, ftype, 518 error); 519 dab_fatal(tf, fsr, far, l, NULL); 520 } 521 522 KSI_INIT_TRAP(&ksi); 523 524 switch (error) { 525 case ENOMEM: 526 printf("UVM: pid %d (%s), uid %d killed: " 527 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 528 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 529 ksi.ksi_signo = SIGKILL; 530 break; 531 case EACCES: 532 ksi.ksi_signo = SIGSEGV; 533 ksi.ksi_code = SEGV_ACCERR; 534 break; 535 case EINVAL: 536 ksi.ksi_signo = SIGBUS; 537 ksi.ksi_code = BUS_ADRERR; 538 break; 539 default: 540 ksi.ksi_signo = SIGSEGV; 541 ksi.ksi_code = SEGV_MAPERR; 542 break; 543 } 544 ksi.ksi_addr = (uint32_t *)(intptr_t) far; 545 ksi.ksi_trap = fsr; 546 UVMHIST_LOG(maphist, " <- error (%jd)", error, 0, 0, 0); 547 548 do_trapsignal: 549 call_trapsignal(l, tf, &ksi); 550 out: 551 /* If returning to user mode, make sure to invoke userret() */ 552 if (user) 553 userret(l); 554 } 555 556 /* 557 * dab_fatal() handles the following data aborts: 558 * 559 * FAULT_WRTBUF_0 - Vector Exception 560 * FAULT_WRTBUF_1 - Terminal Exception 561 * 562 * We should never see these on a properly functioning system. 563 * 564 * This function is also called by the other handlers if they 565 * detect a fatal problem. 566 * 567 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 568 */ 569 static int 570 dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 571 { 572 const char * const mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 573 574 if (l != NULL) { 575 printf("Fatal %s mode data abort: '%s'\n", mode, 576 data_aborts[fsr & FAULT_TYPE_MASK].desc); 577 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 578 if ((fsr & FAULT_IMPRECISE) == 0) 579 printf("%08x, ", far); 580 else 581 printf("Invalid, "); 582 printf("spsr=%08x\n", tf->tf_spsr); 583 } else { 584 printf("Fatal %s mode prefetch abort at 0x%08x\n", 585 mode, tf->tf_pc); 586 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 587 } 588 589 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 590 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 591 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 592 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 593 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 594 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 595 printf("r12=%08x, ", tf->tf_r12); 596 597 if (TRAP_USERMODE(tf)) 598 printf("usp=%08x, ulr=%08x", 599 tf->tf_usr_sp, tf->tf_usr_lr); 600 else 601 printf("ssp=%08x, slr=%08x", 602 tf->tf_svc_sp, tf->tf_svc_lr); 603 printf(", pc =%08x\n\n", tf->tf_pc); 604 605 #if defined(DDB) || defined(KGDB) 606 kdb_trap(T_FAULT, tf); 607 #endif 608 panic("Fatal abort"); 609 /*NOTREACHED*/ 610 } 611 612 /* 613 * dab_align() handles the following data aborts: 614 * 615 * FAULT_ALIGN_0 - Alignment fault 616 * FAULT_ALIGN_0 - Alignment fault 617 * 618 * These faults are fatal if they happen in kernel mode. Otherwise, we 619 * deliver a bus error to the process. 620 */ 621 static int 622 dab_align(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) 623 { 624 /* Alignment faults are always fatal if they occur in kernel mode */ 625 if (!TRAP_USERMODE(tf)) 626 dab_fatal(tf, fsr, far, l, NULL); 627 628 /* pcb_onfault *must* be NULL at this point */ 629 KDASSERT(((struct pcb *)lwp_getpcb(l))->pcb_onfault == NULL); 630 631 /* See if the CPU state needs to be fixed up */ 632 (void) data_abort_fixup(tf, fsr, far, l); 633 634 /* Deliver a bus error signal to the process */ 635 KSI_INIT_TRAP(ksi); 636 ksi->ksi_signo = SIGBUS; 637 ksi->ksi_code = BUS_ADRALN; 638 ksi->ksi_addr = (uint32_t *)(intptr_t)far; 639 ksi->ksi_trap = fsr; 640 641 KASSERTMSG(tf == lwp_trapframe(l), "tf %p vs %p", tf, lwp_trapframe(l)); 642 643 return 1; 644 } 645 646 /* 647 * dab_buserr() handles the following data aborts: 648 * 649 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 650 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 651 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 652 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 653 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 654 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 655 * 656 * If pcb_onfault is set, flag the fault and return to the handler. 657 * If the fault occurred in user mode, give the process a SIGBUS. 658 * 659 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 660 * can be flagged as imprecise in the FSR. This causes a real headache 661 * since some of the machine state is lost. In this case, tf->tf_pc 662 * may not actually point to the offending instruction. In fact, if 663 * we've taken a double abort fault, it generally points somewhere near 664 * the top of "data_abort_entry" in exception.S. 665 * 666 * In all other cases, these data aborts are considered fatal. 667 */ 668 static int 669 dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, 670 ksiginfo_t *ksi) 671 { 672 struct pcb *pcb = lwp_getpcb(l); 673 674 #ifdef __XSCALE__ 675 if ((fsr & FAULT_IMPRECISE) != 0 && 676 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 677 /* 678 * Oops, an imprecise, double abort fault. We've lost the 679 * r14_abt/spsr_abt values corresponding to the original 680 * abort, and the spsr saved in the trapframe indicates 681 * ABT mode. 682 */ 683 tf->tf_spsr &= ~PSR_MODE; 684 685 /* 686 * We use a simple heuristic to determine if the double abort 687 * happened as a result of a kernel or user mode access. 688 * If the current trapframe is at the top of the kernel stack, 689 * the fault _must_ have come from user mode. 690 */ 691 if (tf != ((trapframe_t *)pcb->pcb_ksp) - 1) { 692 /* 693 * Kernel mode. We're either about to die a 694 * spectacular death, or pcb_onfault will come 695 * to our rescue. Either way, the current value 696 * of tf->tf_pc is irrelevant. 697 */ 698 tf->tf_spsr |= PSR_SVC32_MODE; 699 if (pcb->pcb_onfault == NULL) 700 printf("\nKernel mode double abort!\n"); 701 } else { 702 /* 703 * User mode. We've lost the program counter at the 704 * time of the fault (not that it was accurate anyway; 705 * it's not called an imprecise fault for nothing). 706 * About all we can do is copy r14_usr to tf_pc and 707 * hope for the best. The process is about to get a 708 * SIGBUS, so it's probably history anyway. 709 */ 710 tf->tf_spsr |= PSR_USR32_MODE; 711 tf->tf_pc = tf->tf_usr_lr; 712 #ifdef THUMB_CODE 713 tf->tf_spsr &= ~PSR_T_bit; 714 if (tf->tf_usr_lr & 1) 715 tf->tf_spsr |= PSR_T_bit; 716 #endif 717 } 718 } 719 720 /* FAR is invalid for imprecise exceptions */ 721 if ((fsr & FAULT_IMPRECISE) != 0) 722 far = 0; 723 #endif /* __XSCALE__ */ 724 725 if (pcb->pcb_onfault) { 726 KDASSERT(TRAP_USERMODE(tf) == 0); 727 tf->tf_r0 = EFAULT; 728 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 729 return 0; 730 } 731 732 /* See if the CPU state needs to be fixed up */ 733 (void) data_abort_fixup(tf, fsr, far, l); 734 735 /* 736 * At this point, if the fault happened in kernel mode, we're toast 737 */ 738 if (!TRAP_USERMODE(tf)) 739 dab_fatal(tf, fsr, far, l, NULL); 740 741 /* Deliver a bus error signal to the process */ 742 KSI_INIT_TRAP(ksi); 743 ksi->ksi_signo = SIGBUS; 744 ksi->ksi_code = BUS_ADRERR; 745 ksi->ksi_addr = (uint32_t *)(intptr_t)far; 746 ksi->ksi_trap = fsr; 747 748 KASSERTMSG(tf == lwp_trapframe(l), "tf %p vs %p", tf, lwp_trapframe(l)); 749 750 return 1; 751 } 752 753 static inline int 754 prefetch_abort_fixup(trapframe_t *tf) 755 { 756 #ifdef CPU_ABORT_FIXUP_REQUIRED 757 int error; 758 759 /* Call the CPU specific prefetch abort fixup routine */ 760 error = cpu_prefetchabt_fixup(tf); 761 if (__predict_true(error != ABORT_FIXUP_FAILED)) 762 return error; 763 764 /* 765 * Oops, couldn't fix up the instruction 766 */ 767 printf("%s: fixup for %s mode prefetch abort failed.\n", __func__, 768 TRAP_USERMODE(tf) ? "user" : "kernel"); 769 #ifdef THUMB_CODE 770 if (tf->tf_spsr & PSR_T_bit) { 771 printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", 772 tf->tf_pc, *((uint16 *)(tf->tf_pc & ~1)), 773 *((uint16 *)((tf->tf_pc + 2) & ~1))); 774 } 775 else 776 #endif 777 { 778 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 779 *((u_int *)tf->tf_pc)); 780 } 781 disassemble(tf->tf_pc); 782 783 /* Die now if this happened in kernel mode */ 784 if (!TRAP_USERMODE(tf)) 785 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 786 787 return error; 788 #else 789 return ABORT_FIXUP_OK; 790 #endif /* CPU_ABORT_FIXUP_REQUIRED */ 791 } 792 793 /* 794 * void prefetch_abort_handler(trapframe_t *tf) 795 * 796 * Abort handler called when instruction execution occurs at 797 * a non existent or restricted (access permissions) memory page. 798 * If the address is invalid and we were in SVC mode then panic as 799 * the kernel should never prefetch abort. 800 * If the address is invalid and the page is mapped then the user process 801 * does not have read permission so send it a signal. 802 * Otherwise fault the page in and try again. 803 */ 804 void 805 prefetch_abort_handler(trapframe_t *tf) 806 { 807 struct lwp *l; 808 struct pcb *pcb __diagused; 809 struct vm_map *map; 810 vaddr_t fault_pc, va; 811 ksiginfo_t ksi; 812 int error, user; 813 814 UVMHIST_FUNC(__func__); 815 UVMHIST_CALLED(maphist); 816 817 /* Update vmmeter statistics */ 818 curcpu()->ci_data.cpu_ntrap++; 819 820 l = curlwp; 821 pcb = lwp_getpcb(l); 822 user = TRAP_USERMODE(tf) != 0; 823 824 /* 825 * Enable IRQ's (disabled by the abort) This always comes 826 * from user mode so we know interrupts were not disabled. 827 * But we check anyway. 828 */ 829 KASSERT(!user || VALID_PSR(tf->tf_spsr)); 830 #ifdef __NO_FIQ 831 if (__predict_true((tf->tf_spsr & I32_bit) != I32_bit)) 832 restore_interrupts(tf->tf_spsr & IF32_bits); 833 #else 834 if (__predict_true((tf->tf_spsr & IF32_bits) != IF32_bits)) 835 restore_interrupts(tf->tf_spsr & IF32_bits); 836 #endif 837 838 /* See if the CPU state needs to be fixed up */ 839 switch (prefetch_abort_fixup(tf)) { 840 case ABORT_FIXUP_RETURN: 841 KASSERT(!TRAP_USERMODE(tf) || VALID_PSR(tf->tf_spsr)); 842 return; 843 case ABORT_FIXUP_FAILED: 844 /* Deliver a SIGILL to the process */ 845 KSI_INIT_TRAP(&ksi); 846 ksi.ksi_signo = SIGILL; 847 ksi.ksi_code = ILL_ILLOPC; 848 ksi.ksi_addr = (uint32_t *)(intptr_t) tf->tf_pc; 849 KASSERTMSG(tf == lwp_trapframe(l), "tf %p vs %p", tf, 850 lwp_trapframe(l)); 851 goto do_trapsignal; 852 default: 853 break; 854 } 855 856 /* Prefetch aborts cannot happen in kernel mode */ 857 if (__predict_false(!user)) 858 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 859 860 /* Get fault address */ 861 fault_pc = tf->tf_pc; 862 KASSERTMSG(tf == lwp_trapframe(l), "tf %p vs %p", tf, lwp_trapframe(l)); 863 UVMHIST_LOG(maphist, " (pc=%#jx, l=%#jx, tf=%#jx)", 864 fault_pc, (uintptr_t)l, (uintptr_t)tf, 0); 865 866 #ifdef THUMB_CODE 867 recheck: 868 #endif 869 /* Ok validate the address, can only execute in USER space */ 870 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 871 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 872 KSI_INIT_TRAP(&ksi); 873 ksi.ksi_signo = SIGSEGV; 874 ksi.ksi_code = SEGV_ACCERR; 875 ksi.ksi_addr = (uint32_t *)(intptr_t) fault_pc; 876 ksi.ksi_trap = fault_pc; 877 goto do_trapsignal; 878 } 879 880 map = &l->l_proc->p_vmspace->vm_map; 881 va = trunc_page(fault_pc); 882 883 /* 884 * See if the pmap can handle this fault on its own... 885 */ 886 #if defined(DEBUG) && !defined(MULTIPROCESSOR) 887 last_fault_code = -1; 888 #endif 889 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ|VM_PROT_EXECUTE, 1)) { 890 UVMHIST_LOG (maphist, " <- emulated", 0, 0, 0, 0); 891 goto out; 892 } 893 894 #ifdef DIAGNOSTIC 895 if (__predict_false(curcpu()->ci_intr_depth > 0)) { 896 printf("\nNon-emulated prefetch abort with intr_depth > 0\n"); 897 dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); 898 } 899 #endif 900 901 KASSERT(pcb->pcb_onfault == NULL); 902 error = uvm_fault(map, va, VM_PROT_READ|VM_PROT_EXECUTE); 903 904 if (__predict_true(error == 0)) { 905 UVMHIST_LOG (maphist, " <- uvm", 0, 0, 0, 0); 906 goto out; 907 } 908 KSI_INIT_TRAP(&ksi); 909 910 UVMHIST_LOG (maphist, " <- fatal (%jd)", error, 0, 0, 0); 911 912 if (error == ENOMEM) { 913 printf("UVM: pid %d (%s), uid %d killed: " 914 "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, 915 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); 916 ksi.ksi_signo = SIGKILL; 917 } else 918 ksi.ksi_signo = SIGSEGV; 919 920 ksi.ksi_code = SEGV_MAPERR; 921 ksi.ksi_addr = (uint32_t *)(intptr_t) fault_pc; 922 ksi.ksi_trap = fault_pc; 923 924 do_trapsignal: 925 call_trapsignal(l, tf, &ksi); 926 927 out: 928 929 #ifdef THUMB_CODE 930 #define THUMB_32BIT(hi) (((hi) & 0xe000) == 0xe000 && ((hi) & 0x1800)) 931 /* thumb-32 instruction was located on page boundary? */ 932 if ((tf->tf_spsr & PSR_T_bit) && 933 ((fault_pc & PAGE_MASK) == (PAGE_SIZE - THUMB_INSN_SIZE)) && 934 THUMB_32BIT(*(uint16_t *)tf->tf_pc)) { 935 fault_pc = tf->tf_pc + THUMB_INSN_SIZE; 936 goto recheck; 937 } 938 #endif /* THUMB_CODE */ 939 940 KASSERT(!TRAP_USERMODE(tf) || VALID_PSR(tf->tf_spsr)); 941 userret(l); 942 } 943 944 /* 945 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 946 * If the read succeeds, the value is written to 'rptr' and zero is returned. 947 * Else, return EFAULT. 948 */ 949 int 950 badaddr_read(void *addr, size_t size, void *rptr) 951 { 952 extern int badaddr_read_1(const uint8_t *, uint8_t *); 953 extern int badaddr_read_2(const uint16_t *, uint16_t *); 954 extern int badaddr_read_4(const uint32_t *, uint32_t *); 955 union { 956 uint8_t v1; 957 uint16_t v2; 958 uint32_t v4; 959 } u; 960 int rv, s; 961 962 cpu_drain_writebuf(); 963 964 s = splhigh(); 965 966 /* Read from the test address. */ 967 switch (size) { 968 case sizeof(uint8_t): 969 rv = badaddr_read_1(addr, &u.v1); 970 if (rv == 0 && rptr) 971 *(uint8_t *) rptr = u.v1; 972 break; 973 974 case sizeof(uint16_t): 975 rv = badaddr_read_2(addr, &u.v2); 976 if (rv == 0 && rptr) 977 *(uint16_t *) rptr = u.v2; 978 break; 979 980 case sizeof(uint32_t): 981 rv = badaddr_read_4(addr, &u.v4); 982 if (rv == 0 && rptr) 983 *(uint32_t *) rptr = u.v4; 984 break; 985 986 default: 987 panic("%s: invalid size (%zu)", __func__, size); 988 } 989 990 splx(s); 991 992 /* Return EFAULT if the address was invalid, else zero */ 993 return rv; 994 } 995
Indexes created Mon Sep 22 05:09:51 GMT 2025