trap-v4.c revision 160773
1/* $NetBSD: fault.c,v 1.45 2003/11/20 14:44:36 scw Exp $ */ 2 3/*- 4 * Copyright 2004 Olivier Houchard 5 * Copyright 2003 Wasabi Systems, Inc. 6 * All rights reserved. 7 * 8 * Written by Steve C. Woodford for Wasabi Systems, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed for the NetBSD Project by 21 * Wasabi Systems, Inc. 22 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 23 * or promote products derived from this software without specific prior 24 * written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38/*- 39 * Copyright (c) 1994-1997 Mark Brinicombe. 40 * Copyright (c) 1994 Brini. 41 * All rights reserved. 42 * 43 * This code is derived from software written for Brini by Mark Brinicombe 44 * 45 * Redistribution and use in source and binary forms, with or without 46 * modification, are permitted provided that the following conditions 47 * are met: 48 * 1. Redistributions of source code must retain the above copyright 49 * notice, this list of conditions and the following disclaimer. 50 * 2. Redistributions in binary form must reproduce the above copyright 51 * notice, this list of conditions and the following disclaimer in the 52 * documentation and/or other materials provided with the distribution. 53 * 3. All advertising materials mentioning features or use of this software 54 * must display the following acknowledgement: 55 * This product includes software developed by Brini. 56 * 4. The name of the company nor the name of the author may be used to 57 * endorse or promote products derived from this software without specific 58 * prior written permission. 59 * 60 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED 61 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 62 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 63 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 64 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 65 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 66 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 70 * SUCH DAMAGE. 71 * 72 * RiscBSD kernel project 73 * 74 * fault.c 75 * 76 * Fault handlers 77 * 78 * Created : 28/11/94 79 */ 80 81 82#include "opt_ktrace.h" 83 84#include <sys/cdefs.h> 85__FBSDID("$FreeBSD: head/sys/arm/arm/trap.c 160773 2006-07-27 22:32:30Z jhb $"); 86 87#include <sys/types.h> 88 89#include <sys/param.h> 90#include <sys/systm.h> 91#include <sys/proc.h> 92#include <sys/kernel.h> 93#include <sys/lock.h> 94#include <sys/mutex.h> 95#include <sys/syscall.h> 96#include <sys/sysent.h> 97#include <sys/signalvar.h> 98#include <sys/ktr.h> 99#ifdef KTRACE 100#include <sys/uio.h> 101#include <sys/ktrace.h> 102#endif 103#include <sys/ptrace.h> 104#include <sys/pioctl.h> 105 106#include <vm/vm.h> 107#include <vm/pmap.h> 108#include <vm/vm_kern.h> 109#include <vm/vm_map.h> 110#include <vm/vm_extern.h> 111 112#include <machine/cpuconf.h> 113#include <machine/vmparam.h> 114#include <machine/frame.h> 115#include <machine/katelib.h> 116#include <machine/cpu.h> 117#include <machine/intr.h> 118#include <machine/pcb.h> 119#include <machine/proc.h> 120#include <machine/swi.h> 121 122#include <security/audit/audit.h> 123 124#ifdef KDB 125#include <sys/kdb.h> 126#endif 127 128 129void swi_handler(trapframe_t *); 130void undefinedinstruction(trapframe_t *); 131 132#include <machine/disassem.h> 133#include <machine/machdep.h> 134 135extern char fusubailout[]; 136extern char *syscallnames[]; 137 138#ifdef DEBUG 139int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 140#endif 141 142#if defined(CPU_ARM7TDMI) 143/* These CPUs may need data/prefetch abort fixups */ 144#define CPU_ABORT_FIXUP_REQUIRED 145#endif 146 147struct ksig { 148 int signb; 149 u_long code; 150}; 151struct data_abort { 152 int (*func)(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 153 const char *desc; 154}; 155 156static int dab_fatal(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 157static int dab_align(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 158static int dab_buserr(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 159 160static const struct data_abort data_aborts[] = { 161 {dab_fatal, "Vector Exception"}, 162 {dab_align, "Alignment Fault 1"}, 163 {dab_fatal, "Terminal Exception"}, 164 {dab_align, "Alignment Fault 3"}, 165 {dab_buserr, "External Linefetch Abort (S)"}, 166 {NULL, "Translation Fault (S)"}, 167 {dab_buserr, "External Linefetch Abort (P)"}, 168 {NULL, "Translation Fault (P)"}, 169 {dab_buserr, "External Non-Linefetch Abort (S)"}, 170 {NULL, "Domain Fault (S)"}, 171 {dab_buserr, "External Non-Linefetch Abort (P)"}, 172 {NULL, "Domain Fault (P)"}, 173 {dab_buserr, "External Translation Abort (L1)"}, 174 {NULL, "Permission Fault (S)"}, 175 {dab_buserr, "External Translation Abort (L2)"}, 176 {NULL, "Permission Fault (P)"} 177}; 178 179/* Determine if a fault came from user mode */ 180#define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE) 181 182/* Determine if 'x' is a permission fault */ 183#define IS_PERMISSION_FAULT(x) \ 184 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 185 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 186 187static __inline void 188call_trapsignal(struct thread *td, int sig, u_long code) 189{ 190 ksiginfo_t ksi; 191 192 ksiginfo_init_trap(&ksi); 193 ksi.ksi_signo = sig; 194 ksi.ksi_code = (int)code; 195 trapsignal(td, &ksi); 196} 197 198static __inline int 199data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 200{ 201#ifdef CPU_ABORT_FIXUP_REQUIRED 202 int error; 203 204 /* Call the cpu specific data abort fixup routine */ 205 error = cpu_dataabt_fixup(tf); 206 if (__predict_true(error != ABORT_FIXUP_FAILED)) 207 return (error); 208 209 /* 210 * Oops, couldn't fix up the instruction 211 */ 212 printf("data_abort_fixup: fixup for %s mode data abort failed.\n", 213 TRAP_USERMODE(tf) ? "user" : "kernel"); 214 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 215 *((u_int *)tf->tf_pc)); 216 disassemble(tf->tf_pc); 217 218 /* Die now if this happened in kernel mode */ 219 if (!TRAP_USERMODE(tf)) 220 dab_fatal(tf, fsr, far, td, NULL, ksig); 221 222 return (error); 223#else 224 return (ABORT_FIXUP_OK); 225#endif /* CPU_ABORT_FIXUP_REQUIRED */ 226} 227 228void 229data_abort_handler(trapframe_t *tf) 230{ 231 struct vm_map *map; 232 struct pcb *pcb; 233 struct thread *td; 234 u_int user, far, fsr; 235 vm_prot_t ftype; 236 void *onfault; 237 vm_offset_t va; 238 int error = 0; 239 struct ksig ksig; 240 struct proc *p; 241 242 243 /* Grab FAR/FSR before enabling interrupts */ 244 far = cpu_faultaddress(); 245 fsr = cpu_faultstatus(); 246#if 0 247 printf("data abort: %p (from %p %p)\n", (void*)far, (void*)tf->tf_pc, 248 (void*)tf->tf_svc_lr); 249#endif 250 251 /* Update vmmeter statistics */ 252#if 0 253 vmexp.traps++; 254#endif 255 256 td = curthread; 257 p = td->td_proc; 258 259 PCPU_LAZY_INC(cnt.v_trap); 260 /* Data abort came from user mode? */ 261 user = TRAP_USERMODE(tf); 262 263 if (user) { 264 td->td_pticks = 0; 265 td->td_frame = tf; 266 if (td->td_ucred != td->td_proc->p_ucred) 267 cred_update_thread(td); 268 if (td->td_pflags & TDP_SA) 269 thread_user_enter(td); 270 271 } 272 /* Grab the current pcb */ 273 pcb = td->td_pcb; 274 /* Re-enable interrupts if they were enabled previously */ 275 if (td->td_md.md_spinlock_count == 0) { 276 if (__predict_true(tf->tf_spsr & I32_bit) == 0) 277 enable_interrupts(I32_bit); 278 if (__predict_true(tf->tf_spsr & F32_bit) == 0) 279 enable_interrupts(F32_bit); 280 } 281 282 283 /* Invoke the appropriate handler, if necessary */ 284 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 285 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 286 td, &ksig)) { 287 goto do_trapsignal; 288 } 289 goto out; 290 } 291 292 /* 293 * At this point, we're dealing with one of the following data aborts: 294 * 295 * FAULT_TRANS_S - Translation -- Section 296 * FAULT_TRANS_P - Translation -- Page 297 * FAULT_DOMAIN_S - Domain -- Section 298 * FAULT_DOMAIN_P - Domain -- Page 299 * FAULT_PERM_S - Permission -- Section 300 * FAULT_PERM_P - Permission -- Page 301 * 302 * These are the main virtual memory-related faults signalled by 303 * the MMU. 304 */ 305 306 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 307 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 308 tf->tf_r0 = EFAULT; 309 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 310 return; 311 } 312 313 /* 314 * Make sure the Program Counter is sane. We could fall foul of 315 * someone executing Thumb code, in which case the PC might not 316 * be word-aligned. This would cause a kernel alignment fault 317 * further down if we have to decode the current instruction. 318 * XXX: It would be nice to be able to support Thumb at some point. 319 */ 320 if (__predict_false((tf->tf_pc & 3) != 0)) { 321 if (user) { 322 /* 323 * Give the user an illegal instruction signal. 324 */ 325 /* Deliver a SIGILL to the process */ 326 ksig.signb = SIGILL; 327 ksig.code = 0; 328 goto do_trapsignal; 329 } 330 331 /* 332 * The kernel never executes Thumb code. 333 */ 334 printf("\ndata_abort_fault: Misaligned Kernel-mode " 335 "Program Counter\n"); 336 dab_fatal(tf, fsr, far, td, &ksig); 337 } 338 339 /* See if the cpu state needs to be fixed up */ 340 switch (data_abort_fixup(tf, fsr, far, td, &ksig)) { 341 case ABORT_FIXUP_RETURN: 342 return; 343 case ABORT_FIXUP_FAILED: 344 /* Deliver a SIGILL to the process */ 345 ksig.signb = SIGILL; 346 ksig.code = 0; 347 goto do_trapsignal; 348 default: 349 break; 350 } 351 352 va = trunc_page((vm_offset_t)far); 353 354 /* 355 * It is only a kernel address space fault iff: 356 * 1. user == 0 and 357 * 2. pcb_onfault not set or 358 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 359 */ 360 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 361 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 362 __predict_true((pcb->pcb_onfault == NULL || 363 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 364 map = kernel_map; 365 366 /* Was the fault due to the FPE/IPKDB ? */ 367 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 368 369 /* 370 * Force exit via userret() 371 * This is necessary as the FPE is an extension to 372 * userland that actually runs in a priveledged mode 373 * but uses USR mode permissions for its accesses. 374 */ 375 user = 1; 376 ksig.signb = SIGSEGV; 377 ksig.code = 0; 378 goto do_trapsignal; 379 } 380 } else { 381 map = &td->td_proc->p_vmspace->vm_map; 382 } 383 384 /* 385 * We need to know whether the page should be mapped 386 * as R or R/W. The MMU does not give us the info as 387 * to whether the fault was caused by a read or a write. 388 * 389 * However, we know that a permission fault can only be 390 * the result of a write to a read-only location, so 391 * we can deal with those quickly. 392 * 393 * Otherwise we need to disassemble the instruction 394 * responsible to determine if it was a write. 395 */ 396 if (IS_PERMISSION_FAULT(fsr)) { 397 ftype = VM_PROT_WRITE; 398 } else { 399 u_int insn = ReadWord(tf->tf_pc); 400 401 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */ 402 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */ 403 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT */ 404 { 405 ftype = VM_PROT_WRITE; 406 } 407 else 408 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */ 409 ftype = VM_PROT_READ | VM_PROT_WRITE; 410 else 411 ftype = VM_PROT_READ; 412 } 413 414 /* 415 * See if the fault is as a result of ref/mod emulation, 416 * or domain mismatch. 417 */ 418#ifdef DEBUG 419 last_fault_code = fsr; 420#endif 421 if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype, 422 user)) { 423 goto out; 424 } 425 426 onfault = pcb->pcb_onfault; 427 pcb->pcb_onfault = NULL; 428 if (map != kernel_map) { 429 PROC_LOCK(p); 430 p->p_lock++; 431 PROC_UNLOCK(p); 432 } 433 error = vm_fault(map, va, ftype, (ftype & VM_PROT_WRITE) ? 434 VM_FAULT_DIRTY : VM_FAULT_NORMAL); 435 pcb->pcb_onfault = onfault; 436 437 if (map != kernel_map) { 438 PROC_LOCK(p); 439 p->p_lock--; 440 PROC_UNLOCK(p); 441 } 442 if (__predict_true(error == 0)) 443 goto out; 444 if (user == 0) { 445 if (pcb->pcb_onfault) { 446 tf->tf_r0 = error; 447 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 448 return; 449 } 450 451 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype, 452 error); 453 dab_fatal(tf, fsr, far, td, &ksig); 454 } 455 456 457 if (error == ENOMEM) { 458 printf("VM: pid %d (%s), uid %d killed: " 459 "out of swap\n", td->td_proc->p_pid, td->td_proc->p_comm, 460 (td->td_proc->p_ucred) ? 461 td->td_proc->p_ucred->cr_uid : -1); 462 ksig.signb = SIGKILL; 463 } else { 464 ksig.signb = SIGSEGV; 465 } 466 ksig.code = 0; 467do_trapsignal: 468 call_trapsignal(td, ksig.signb, ksig.code); 469out: 470 /* If returning to user mode, make sure to invoke userret() */ 471 if (user) 472 userret(td, tf); 473} 474 475/* 476 * dab_fatal() handles the following data aborts: 477 * 478 * FAULT_WRTBUF_0 - Vector Exception 479 * FAULT_WRTBUF_1 - Terminal Exception 480 * 481 * We should never see these on a properly functioning system. 482 * 483 * This function is also called by the other handlers if they 484 * detect a fatal problem. 485 * 486 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 487 */ 488static int 489dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 490{ 491 const char *mode; 492 493 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 494 495 disable_interrupts(I32_bit|F32_bit); 496 if (td != NULL) { 497 printf("Fatal %s mode data abort: '%s'\n", mode, 498 data_aborts[fsr & FAULT_TYPE_MASK].desc); 499 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 500 if ((fsr & FAULT_IMPRECISE) == 0) 501 printf("%08x, ", far); 502 else 503 printf("Invalid, "); 504 printf("spsr=%08x\n", tf->tf_spsr); 505 } else { 506 printf("Fatal %s mode prefetch abort at 0x%08x\n", 507 mode, tf->tf_pc); 508 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 509 } 510 511 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 512 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 513 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 514 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 515 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 516 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 517 printf("r12=%08x, ", tf->tf_r12); 518 519 if (TRAP_USERMODE(tf)) 520 printf("usp=%08x, ulr=%08x", 521 tf->tf_usr_sp, tf->tf_usr_lr); 522 else 523 printf("ssp=%08x, slr=%08x", 524 tf->tf_svc_sp, tf->tf_svc_lr); 525 printf(", pc =%08x\n\n", tf->tf_pc); 526 527#ifdef KDB 528 kdb_trap(fsr, 0, tf); 529#endif 530 panic("Fatal abort"); 531 /*NOTREACHED*/ 532} 533 534/* 535 * dab_align() handles the following data aborts: 536 * 537 * FAULT_ALIGN_0 - Alignment fault 538 * FAULT_ALIGN_0 - Alignment fault 539 * 540 * These faults are fatal if they happen in kernel mode. Otherwise, we 541 * deliver a bus error to the process. 542 */ 543static int 544dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 545{ 546 547 /* Alignment faults are always fatal if they occur in kernel mode */ 548 if (!TRAP_USERMODE(tf)) { 549 if (!td || !td->td_pcb->pcb_onfault) 550 dab_fatal(tf, fsr, far, td, ksig); 551 tf->tf_r0 = EFAULT; 552 tf->tf_pc = (int)td->td_pcb->pcb_onfault; 553 return (0); 554 } 555 556 /* pcb_onfault *must* be NULL at this point */ 557 558 /* See if the cpu state needs to be fixed up */ 559 (void) data_abort_fixup(tf, fsr, far, td, ksig); 560 561 /* Deliver a bus error signal to the process */ 562 ksig->code = 0; 563 ksig->signb = SIGBUS; 564 td->td_frame = tf; 565 566 return (1); 567} 568 569/* 570 * dab_buserr() handles the following data aborts: 571 * 572 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 573 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 574 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 575 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 576 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 577 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 578 * 579 * If pcb_onfault is set, flag the fault and return to the handler. 580 * If the fault occurred in user mode, give the process a SIGBUS. 581 * 582 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 583 * can be flagged as imprecise in the FSR. This causes a real headache 584 * since some of the machine state is lost. In this case, tf->tf_pc 585 * may not actually point to the offending instruction. In fact, if 586 * we've taken a double abort fault, it generally points somewhere near 587 * the top of "data_abort_entry" in exception.S. 588 * 589 * In all other cases, these data aborts are considered fatal. 590 */ 591static int 592dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 593{ 594 struct pcb *pcb = td->td_pcb; 595 596#ifdef __XSCALE__ 597 if ((fsr & FAULT_IMPRECISE) != 0 && 598 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 599 /* 600 * Oops, an imprecise, double abort fault. We've lost the 601 * r14_abt/spsr_abt values corresponding to the original 602 * abort, and the spsr saved in the trapframe indicates 603 * ABT mode. 604 */ 605 tf->tf_spsr &= ~PSR_MODE; 606 607 /* 608 * We use a simple heuristic to determine if the double abort 609 * happened as a result of a kernel or user mode access. 610 * If the current trapframe is at the top of the kernel stack, 611 * the fault _must_ have come from user mode. 612 */ 613 if (tf != ((trapframe_t *)pcb->un_32.pcb32_sp) - 1) { 614 /* 615 * Kernel mode. We're either about to die a 616 * spectacular death, or pcb_onfault will come 617 * to our rescue. Either way, the current value 618 * of tf->tf_pc is irrelevant. 619 */ 620 tf->tf_spsr |= PSR_SVC32_MODE; 621 if (pcb->pcb_onfault == NULL) 622 printf("\nKernel mode double abort!\n"); 623 } else { 624 /* 625 * User mode. We've lost the program counter at the 626 * time of the fault (not that it was accurate anyway; 627 * it's not called an imprecise fault for nothing). 628 * About all we can do is copy r14_usr to tf_pc and 629 * hope for the best. The process is about to get a 630 * SIGBUS, so it's probably history anyway. 631 */ 632 tf->tf_spsr |= PSR_USR32_MODE; 633 tf->tf_pc = tf->tf_usr_lr; 634 } 635 } 636 637 /* FAR is invalid for imprecise exceptions */ 638 if ((fsr & FAULT_IMPRECISE) != 0) 639 far = 0; 640#endif /* __XSCALE__ */ 641 642 if (pcb->pcb_onfault) { 643 tf->tf_r0 = EFAULT; 644 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 645 return (0); 646 } 647 648 /* See if the cpu state needs to be fixed up */ 649 (void) data_abort_fixup(tf, fsr, far, td, ksig); 650 651 /* 652 * At this point, if the fault happened in kernel mode, we're toast 653 */ 654 if (!TRAP_USERMODE(tf)) 655 dab_fatal(tf, fsr, far, td, ksig); 656 657 /* Deliver a bus error signal to the process */ 658 ksig->signb = SIGBUS; 659 ksig->code = 0; 660 td->td_frame = tf; 661 662 return (1); 663} 664 665static __inline int 666prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig) 667{ 668#ifdef CPU_ABORT_FIXUP_REQUIRED 669 int error; 670 671 /* Call the cpu specific prefetch abort fixup routine */ 672 error = cpu_prefetchabt_fixup(tf); 673 if (__predict_true(error != ABORT_FIXUP_FAILED)) 674 return (error); 675 676 /* 677 * Oops, couldn't fix up the instruction 678 */ 679 printf( 680 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n", 681 TRAP_USERMODE(tf) ? "user" : "kernel"); 682 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 683 *((u_int *)tf->tf_pc)); 684 disassemble(tf->tf_pc); 685 686 /* Die now if this happened in kernel mode */ 687 if (!TRAP_USERMODE(tf)) 688 dab_fatal(tf, 0, tf->tf_pc, NULL, ksig); 689 690 return (error); 691#else 692 return (ABORT_FIXUP_OK); 693#endif /* CPU_ABORT_FIXUP_REQUIRED */ 694} 695 696/* 697 * void prefetch_abort_handler(trapframe_t *tf) 698 * 699 * Abort handler called when instruction execution occurs at 700 * a non existent or restricted (access permissions) memory page. 701 * If the address is invalid and we were in SVC mode then panic as 702 * the kernel should never prefetch abort. 703 * If the address is invalid and the page is mapped then the user process 704 * does no have read permission so send it a signal. 705 * Otherwise fault the page in and try again. 706 */ 707void 708prefetch_abort_handler(trapframe_t *tf) 709{ 710 struct thread *td; 711 struct proc * p; 712 struct vm_map *map; 713 vm_offset_t fault_pc, va; 714 int error = 0; 715 struct ksig ksig; 716 717 718#if 0 719 /* Update vmmeter statistics */ 720 uvmexp.traps++; 721#endif 722#if 0 723 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, 724 (void*)tf->tf_usr_lr); 725#endif 726 727 td = curthread; 728 p = td->td_proc; 729 PCPU_LAZY_INC(cnt.v_trap); 730 731 if (TRAP_USERMODE(tf)) { 732 td->td_frame = tf; 733 if (td->td_ucred != td->td_proc->p_ucred) 734 cred_update_thread(td); 735 if (td->td_proc->p_flag & P_SA) 736 thread_user_enter(td); 737 } 738 fault_pc = tf->tf_pc; 739 if (td->td_md.md_spinlock_count == 0) { 740 if (__predict_true(tf->tf_spsr & I32_bit) == 0) 741 enable_interrupts(I32_bit); 742 if (__predict_true(tf->tf_spsr & F32_bit) == 0) 743 enable_interrupts(F32_bit); 744 } 745 746 747 748 /* See if the cpu state needs to be fixed up */ 749 switch (prefetch_abort_fixup(tf, &ksig)) { 750 case ABORT_FIXUP_RETURN: 751 return; 752 case ABORT_FIXUP_FAILED: 753 /* Deliver a SIGILL to the process */ 754 ksig.signb = SIGILL; 755 ksig.code = 0; 756 td->td_frame = tf; 757 goto do_trapsignal; 758 default: 759 break; 760 } 761 762 /* Prefetch aborts cannot happen in kernel mode */ 763 if (__predict_false(!TRAP_USERMODE(tf))) 764 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); 765 td->td_pticks = 0; 766 767 768 /* Ok validate the address, can only execute in USER space */ 769 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 770 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 771 ksig.signb = SIGSEGV; 772 ksig.code = 0; 773 goto do_trapsignal; 774 } 775 776 map = &td->td_proc->p_vmspace->vm_map; 777 va = trunc_page(fault_pc); 778 779 /* 780 * See if the pmap can handle this fault on its own... 781 */ 782#ifdef DEBUG 783 last_fault_code = -1; 784#endif 785 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) 786 goto out; 787 788 if (map != kernel_map) { 789 PROC_LOCK(p); 790 p->p_lock++; 791 PROC_UNLOCK(p); 792 } 793 794 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, 795 VM_FAULT_NORMAL); 796 if (map != kernel_map) { 797 PROC_LOCK(p); 798 p->p_lock--; 799 PROC_UNLOCK(p); 800 } 801 802 if (__predict_true(error == 0)) 803 goto out; 804 805 if (error == ENOMEM) { 806 printf("VM: pid %d (%s), uid %d killed: " 807 "out of swap\n", td->td_proc->p_pid, td->td_proc->p_comm, 808 (td->td_proc->p_ucred) ? 809 td->td_proc->p_ucred->cr_uid : -1); 810 ksig.signb = SIGKILL; 811 } else { 812 ksig.signb = SIGSEGV; 813 } 814 ksig.code = 0; 815 816do_trapsignal: 817 call_trapsignal(td, ksig.signb, ksig.code); 818 819out: 820 userret(td, tf); 821 822} 823 824extern int badaddr_read_1(const uint8_t *, uint8_t *); 825extern int badaddr_read_2(const uint16_t *, uint16_t *); 826extern int badaddr_read_4(const uint32_t *, uint32_t *); 827/* 828 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 829 * If the read succeeds, the value is written to 'rptr' and zero is returned. 830 * Else, return EFAULT. 831 */ 832int 833badaddr_read(void *addr, size_t size, void *rptr) 834{ 835 union { 836 uint8_t v1; 837 uint16_t v2; 838 uint32_t v4; 839 } u; 840 int rv; 841 842 cpu_drain_writebuf(); 843 844 /* Read from the test address. */ 845 switch (size) { 846 case sizeof(uint8_t): 847 rv = badaddr_read_1(addr, &u.v1); 848 if (rv == 0 && rptr) 849 *(uint8_t *) rptr = u.v1; 850 break; 851 852 case sizeof(uint16_t): 853 rv = badaddr_read_2(addr, &u.v2); 854 if (rv == 0 && rptr) 855 *(uint16_t *) rptr = u.v2; 856 break; 857 858 case sizeof(uint32_t): 859 rv = badaddr_read_4(addr, &u.v4); 860 if (rv == 0 && rptr) 861 *(uint32_t *) rptr = u.v4; 862 break; 863 864 default: 865 panic("badaddr: invalid size (%lu)", (u_long) size); 866 } 867 868 /* Return EFAULT if the address was invalid, else zero */ 869 return (rv); 870} 871 872#define MAXARGS 8 873static void 874syscall(struct thread *td, trapframe_t *frame, u_int32_t insn) 875{ 876 struct proc *p = td->td_proc; 877 int code, error; 878 u_int nap, nargs; 879 register_t *ap, *args, copyargs[MAXARGS]; 880 struct sysent *callp; 881 int locked = 0; 882 883 PCPU_LAZY_INC(cnt.v_syscall); 884 td->td_pticks = 0; 885 if (td->td_ucred != td->td_proc->p_ucred) 886 cred_update_thread(td); 887 switch (insn & SWI_OS_MASK) { 888 case 0: /* XXX: we need our own one. */ 889 nap = 4; 890 break; 891 default: 892 call_trapsignal(td, SIGILL, 0); 893 userret(td, frame); 894 return; 895 } 896 code = insn & 0x000fffff; 897 td->td_pticks = 0; 898 ap = &frame->tf_r0; 899 if (code == SYS_syscall) { 900 code = *ap++; 901 902 nap--; 903 } else if (code == SYS___syscall) { 904 code = *ap++; 905 nap -= 2; 906 ap++; 907 } 908 if (p->p_sysent->sv_mask) 909 code &= p->p_sysent->sv_mask; 910 if (code >= p->p_sysent->sv_size) 911 callp = &p->p_sysent->sv_table[0]; 912 else 913 callp = &p->p_sysent->sv_table[code]; 914 nargs = callp->sy_narg & SYF_ARGMASK; 915 memcpy(copyargs, ap, nap * sizeof(register_t)); 916 if (nargs > nap) { 917 error = copyin((void *)frame->tf_usr_sp, copyargs + nap, 918 (nargs - nap) * sizeof(register_t)); 919 if (error) 920 goto bad; 921 } 922 args = copyargs; 923 error = 0; 924#ifdef KTRACE 925 if (KTRPOINT(td, KTR_SYSCALL)) 926 ktrsyscall(code, nargs, args); 927#endif 928 929 CTR4(KTR_SYSC, "syscall enter thread %p pid %d proc %s code %d", td, 930 td->td_proc->p_pid, td->td_proc->p_comm, code); 931 if ((callp->sy_narg & SYF_MPSAFE) == 0) 932 mtx_lock(&Giant); 933 locked = 1; 934 if (error == 0) { 935 td->td_retval[0] = 0; 936 td->td_retval[1] = 0; 937 STOPEVENT(p, S_SCE, (callp->sy_narg & SYF_ARGMASK)); 938 PTRACESTOP_SC(p, td, S_PT_SCE); 939 AUDIT_SYSCALL_ENTER(code, td); 940 error = (*callp->sy_call)(td, args); 941 AUDIT_SYSCALL_EXIT(error, td); 942 KASSERT(td->td_ar == NULL, 943 ("returning from syscall with td_ar set!")); 944 } 945 switch (error) { 946 case 0: 947#ifdef __ARMEB__ 948 if ((insn & 0x000fffff) && 949 (code != SYS_lseek)) { 950 /* 951 * 64-bit return, 32-bit syscall. Fixup byte order 952 */ 953 frame->tf_r0 = 0; 954 frame->tf_r1 = td->td_retval[0]; 955 } else { 956 frame->tf_r0 = td->td_retval[0]; 957 frame->tf_r1 = td->td_retval[1]; 958 } 959#else 960 frame->tf_r0 = td->td_retval[0]; 961 frame->tf_r1 = td->td_retval[1]; 962#endif 963 frame->tf_spsr &= ~PSR_C_bit; /* carry bit */ 964 break; 965 966 case ERESTART: 967 /* 968 * Reconstruct the pc to point at the swi. 969 */ 970 frame->tf_pc -= INSN_SIZE; 971 break; 972 case EJUSTRETURN: 973 /* nothing to do */ 974 break; 975 default: 976bad: 977 frame->tf_r0 = error; 978 frame->tf_spsr |= PSR_C_bit; /* carry bit */ 979 break; 980 } 981 if (locked && (callp->sy_narg & SYF_MPSAFE) == 0) 982 mtx_unlock(&Giant); 983 984 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning", 985 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???"); 986 KASSERT(td->td_critnest == 0, 987 ("System call %s returning in a critical section", 988 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???")); 989 KASSERT(td->td_locks == 0, 990 ("System call %s returning with %d locks held", 991 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???", 992 td->td_locks)); 993 994 userret(td, frame); 995 CTR4(KTR_SYSC, "syscall exit thread %p pid %d proc %s code %d", td, 996 td->td_proc->p_pid, td->td_proc->p_comm, code); 997 998 STOPEVENT(p, S_SCX, code); 999 PTRACESTOP_SC(p, td, S_PT_SCX); 1000#ifdef KTRACE 1001 if (KTRPOINT(td, KTR_SYSRET)) 1002 ktrsysret(code, error, td->td_retval[0]); 1003#endif 1004} 1005 1006void 1007swi_handler(trapframe_t *frame) 1008{ 1009 struct thread *td = curthread; 1010 uint32_t insn; 1011 1012 td->td_frame = frame; 1013 1014 td->td_pticks = 0; 1015 if (td->td_proc->p_flag & P_SA) 1016 thread_user_enter(td); 1017 /* 1018 * Make sure the program counter is correctly aligned so we 1019 * don't take an alignment fault trying to read the opcode. 1020 */ 1021 if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) { 1022 call_trapsignal(td, SIGILL, 0); 1023 userret(td, frame); 1024 return; 1025 } 1026 insn = *(u_int32_t *)(frame->tf_pc - INSN_SIZE); 1027 /* 1028 * Enable interrupts if they were enabled before the exception. 1029 * Since all syscalls *should* come from user mode it will always 1030 * be safe to enable them, but check anyway. 1031 */ 1032 if (td->td_md.md_spinlock_count == 0) { 1033 if (__predict_true(frame->tf_spsr & I32_bit) == 0) 1034 enable_interrupts(I32_bit); 1035 if (__predict_true(frame->tf_spsr & F32_bit) == 0) 1036 enable_interrupts(F32_bit); 1037 } 1038 1039 syscall(td, frame, insn); 1040} 1041 1042