syscall.c revision 138129
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 138129 2004-11-27 06:51:39Z das $"); 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#ifdef KTRACE 98#include <sys/uio.h> 99#include <sys/ktrace.h> 100#endif 101 102#include <vm/vm.h> 103#include <vm/pmap.h> 104#include <vm/vm_kern.h> 105#include <vm/vm_map.h> 106#include <vm/vm_extern.h> 107 108#include <machine/cpuconf.h> 109#include <machine/vmparam.h> 110#include <machine/frame.h> 111#include <machine/katelib.h> 112#include <machine/cpu.h> 113#include <machine/intr.h> 114#include <machine/pcb.h> 115#include <machine/proc.h> 116#include <machine/swi.h> 117#if !defined(DDB) 118#define kdb_trap kgdb_trap 119#endif 120 121 122 123void swi_handler(trapframe_t *); 124void undefinedinstruction(trapframe_t *); 125 126#include <machine/disassem.h> 127#include <machine/machdep.h> 128 129extern char fusubailout[]; 130 131#ifdef DEBUG 132int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 133#endif 134 135#if defined(CPU_ARM3) || defined(CPU_ARM6) || \ 136 defined(CPU_ARM7) || defined(CPU_ARM7TDMI) 137/* These CPUs may need data/prefetch abort fixups */ 138#define CPU_ABORT_FIXUP_REQUIRED 139#endif 140 141struct ksig { 142 int signb; 143 u_long code; 144}; 145struct data_abort { 146 int (*func)(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 147 const char *desc; 148}; 149 150static int dab_fatal(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 151static int dab_align(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 152static int dab_buserr(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 153 154static const struct data_abort data_aborts[] = { 155 {dab_fatal, "Vector Exception"}, 156 {dab_align, "Alignment Fault 1"}, 157 {dab_fatal, "Terminal Exception"}, 158 {dab_align, "Alignment Fault 3"}, 159 {dab_buserr, "External Linefetch Abort (S)"}, 160 {NULL, "Translation Fault (S)"}, 161 {dab_buserr, "External Linefetch Abort (P)"}, 162 {NULL, "Translation Fault (P)"}, 163 {dab_buserr, "External Non-Linefetch Abort (S)"}, 164 {NULL, "Domain Fault (S)"}, 165 {dab_buserr, "External Non-Linefetch Abort (P)"}, 166 {NULL, "Domain Fault (P)"}, 167 {dab_buserr, "External Translation Abort (L1)"}, 168 {NULL, "Permission Fault (S)"}, 169 {dab_buserr, "External Translation Abort (L2)"}, 170 {NULL, "Permission Fault (P)"} 171}; 172 173/* Determine if a fault came from user mode */ 174#define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE) 175 176/* Determine if 'x' is a permission fault */ 177#define IS_PERMISSION_FAULT(x) \ 178 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 179 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 180 181static __inline void 182call_trapsignal(struct thread *td, int sig, u_long code) 183{ 184 185 trapsignal(td, sig, code); 186} 187 188static __inline int 189data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 190{ 191#ifdef CPU_ABORT_FIXUP_REQUIRED 192 int error; 193 194 /* Call the cpu specific data abort fixup routine */ 195 error = cpu_dataabt_fixup(tf); 196 if (__predict_true(error != ABORT_FIXUP_FAILED)) 197 return (error); 198 199 /* 200 * Oops, couldn't fix up the instruction 201 */ 202 printf("data_abort_fixup: fixup for %s mode data abort failed.\n", 203 TRAP_USERMODE(tf) ? "user" : "kernel"); 204 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 205 *((u_int *)tf->tf_pc)); 206 disassemble(tf->tf_pc); 207 208 /* Die now if this happened in kernel mode */ 209 if (!TRAP_USERMODE(tf)) 210 dab_fatal(tf, fsr, far, td, NULL, ksig); 211 212 return (error); 213#else 214 return (ABORT_FIXUP_OK); 215#endif /* CPU_ABORT_FIXUP_REQUIRED */ 216} 217 218void 219data_abort_handler(trapframe_t *tf) 220{ 221 struct vm_map *map; 222 struct pcb *pcb; 223 struct thread *td; 224 u_int user, far, fsr; 225 vm_prot_t ftype; 226 void *onfault; 227 vm_offset_t va; 228 u_int sticks = 0; 229 int error = 0; 230 struct ksig ksig; 231 struct proc *p; 232 233 234 /* Grab FAR/FSR before enabling interrupts */ 235 far = cpu_faultaddress(); 236 fsr = cpu_faultstatus(); 237#if 0 238 printf("data abort: %p (from %p %p)\n", (void*)far, (void*)tf->tf_pc, 239 (void*)tf->tf_svc_lr); 240#endif 241 242 /* Update vmmeter statistics */ 243#if 0 244 vmexp.traps++; 245#endif 246 247 td = curthread; 248 p = td->td_proc; 249 250 atomic_add_int(&cnt.v_trap, 1); 251 /* Data abort came from user mode? */ 252 user = TRAP_USERMODE(tf); 253 254 if (user) { 255 sticks = td->td_sticks; td->td_frame = tf; 256 if (td->td_ucred != td->td_proc->p_ucred) 257 cred_update_thread(td); 258 if (td->td_pflags & TDP_SA) 259 thread_user_enter(td); 260 261 } 262 /* Grab the current pcb */ 263 pcb = td->td_pcb; 264 /* Re-enable interrupts if they were enabled previously */ 265 if (td->td_critnest == 0 && __predict_true(tf->tf_spsr & I32_bit) == 0) 266 enable_interrupts(I32_bit); 267 268 /* Invoke the appropriate handler, if necessary */ 269 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 270 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 271 td, &ksig)) { 272 goto do_trapsignal; 273 } 274 goto out; 275 } 276 277 /* 278 * At this point, we're dealing with one of the following data aborts: 279 * 280 * FAULT_TRANS_S - Translation -- Section 281 * FAULT_TRANS_P - Translation -- Page 282 * FAULT_DOMAIN_S - Domain -- Section 283 * FAULT_DOMAIN_P - Domain -- Page 284 * FAULT_PERM_S - Permission -- Section 285 * FAULT_PERM_P - Permission -- Page 286 * 287 * These are the main virtual memory-related faults signalled by 288 * the MMU. 289 */ 290 291 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 292 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 293 tf->tf_r0 = EFAULT; 294 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 295 return; 296 } 297 298 /* 299 * Make sure the Program Counter is sane. We could fall foul of 300 * someone executing Thumb code, in which case the PC might not 301 * be word-aligned. This would cause a kernel alignment fault 302 * further down if we have to decode the current instruction. 303 * XXX: It would be nice to be able to support Thumb at some point. 304 */ 305 if (__predict_false((tf->tf_pc & 3) != 0)) { 306 if (user) { 307 /* 308 * Give the user an illegal instruction signal. 309 */ 310 /* Deliver a SIGILL to the process */ 311 ksig.signb = SIGILL; 312 ksig.code = 0; 313 goto do_trapsignal; 314 } 315 316 /* 317 * The kernel never executes Thumb code. 318 */ 319 printf("\ndata_abort_fault: Misaligned Kernel-mode " 320 "Program Counter\n"); 321 dab_fatal(tf, fsr, far, td, &ksig); 322 } 323 324 /* See if the cpu state needs to be fixed up */ 325 switch (data_abort_fixup(tf, fsr, far, td, &ksig)) { 326 case ABORT_FIXUP_RETURN: 327 return; 328 case ABORT_FIXUP_FAILED: 329 /* Deliver a SIGILL to the process */ 330 ksig.signb = SIGILL; 331 ksig.code = 0; 332 goto do_trapsignal; 333 default: 334 break; 335 } 336 337 va = trunc_page((vm_offset_t)far); 338 339 /* 340 * It is only a kernel address space fault iff: 341 * 1. user == 0 and 342 * 2. pcb_onfault not set or 343 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 344 */ 345 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 346 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 347 __predict_true((pcb->pcb_onfault == NULL || 348 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 349 map = kernel_map; 350 351 /* Was the fault due to the FPE/IPKDB ? */ 352 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 353 354 /* 355 * Force exit via userret() 356 * This is necessary as the FPE is an extension to 357 * userland that actually runs in a priveledged mode 358 * but uses USR mode permissions for its accesses. 359 */ 360 user = 1; 361 ksig.signb = SIGSEGV; 362 ksig.code = 0; 363 goto do_trapsignal; 364 } 365 } else { 366 map = &td->td_proc->p_vmspace->vm_map; 367 } 368 369 /* 370 * We need to know whether the page should be mapped 371 * as R or R/W. The MMU does not give us the info as 372 * to whether the fault was caused by a read or a write. 373 * 374 * However, we know that a permission fault can only be 375 * the result of a write to a read-only location, so 376 * we can deal with those quickly. 377 * 378 * Otherwise we need to disassemble the instruction 379 * responsible to determine if it was a write. 380 */ 381 if (IS_PERMISSION_FAULT(fsr)) { 382 ftype = VM_PROT_WRITE; 383 } else { 384 u_int insn = ReadWord(tf->tf_pc); 385 386 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */ 387 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */ 388 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT */ 389 { 390 ftype = VM_PROT_WRITE; 391 } 392 else 393 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */ 394 ftype = VM_PROT_READ | VM_PROT_WRITE; 395 else 396 ftype = VM_PROT_READ; 397 } 398 399 /* 400 * See if the fault is as a result of ref/mod emulation, 401 * or domain mismatch. 402 */ 403#ifdef DEBUG 404 last_fault_code = fsr; 405#endif 406 if (pmap_fault_fixup(user ? vmspace_pmap(td->td_proc->p_vmspace) : 407 kernel_pmap, va, ftype, user)) { 408 goto out; 409 } 410 411 onfault = pcb->pcb_onfault; 412 pcb->pcb_onfault = NULL; 413 if (map != kernel_map) { 414 PROC_LOCK(p); 415 p->p_lock++; 416 PROC_UNLOCK(p); 417 } 418 error = vm_fault(map, va, ftype, (ftype & VM_PROT_WRITE) ? 419 VM_FAULT_DIRTY : VM_FAULT_NORMAL); 420 pcb->pcb_onfault = onfault; 421 if (__predict_true(error == 0)) { 422 goto out; 423 } 424 425 if (map != kernel_map) { 426 PROC_LOCK(p); 427 p->p_lock++; 428 PROC_UNLOCK(p); 429 } 430 if (user == 0) { 431 if (pcb->pcb_onfault) { 432 tf->tf_r0 = error; 433 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 434 return; 435 } 436 437 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype, 438 error); 439 dab_fatal(tf, fsr, far, td, &ksig); 440 } 441 442 443 if (error == ENOMEM) { 444 printf("VM: pid %d (%s), uid %d killed: " 445 "out of swap\n", td->td_proc->p_pid, td->td_proc->p_comm, 446 (td->td_proc->p_ucred) ? 447 td->td_proc->p_ucred->cr_uid : -1); 448 ksig.signb = SIGKILL; 449 } else { 450 ksig.signb = SIGSEGV; 451 } 452 ksig.code = 0; 453do_trapsignal: 454 call_trapsignal(td, ksig.signb, ksig.code); 455out: 456 /* If returning to user mode, make sure to invoke userret() */ 457 if (user) 458 userret(td, tf, sticks); 459} 460 461/* 462 * dab_fatal() handles the following data aborts: 463 * 464 * FAULT_WRTBUF_0 - Vector Exception 465 * FAULT_WRTBUF_1 - Terminal Exception 466 * 467 * We should never see these on a properly functioning system. 468 * 469 * This function is also called by the other handlers if they 470 * detect a fatal problem. 471 * 472 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 473 */ 474static int 475dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 476{ 477 const char *mode; 478 479 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 480 481 if (td != NULL) { 482 printf("Fatal %s mode data abort: '%s'\n", mode, 483 data_aborts[fsr & FAULT_TYPE_MASK].desc); 484 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 485 if ((fsr & FAULT_IMPRECISE) == 0) 486 printf("%08x, ", far); 487 else 488 printf("Invalid, "); 489 printf("spsr=%08x\n", tf->tf_spsr); 490 } else { 491 printf("Fatal %s mode prefetch abort at 0x%08x\n", 492 mode, tf->tf_pc); 493 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 494 } 495 496 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 497 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 498 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 499 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 500 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 501 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 502 printf("r12=%08x, ", tf->tf_r12); 503 504 if (TRAP_USERMODE(tf)) 505 printf("usp=%08x, ulr=%08x", 506 tf->tf_usr_sp, tf->tf_usr_lr); 507 else 508 printf("ssp=%08x, slr=%08x", 509 tf->tf_svc_sp, tf->tf_svc_lr); 510 printf(", pc =%08x\n\n", tf->tf_pc); 511 512#if defined(DDB) || defined(KGDB) 513 kdb_trap(T_FAULT, tf); 514#endif 515 panic("Fatal abort"); 516 /*NOTREACHED*/ 517} 518 519/* 520 * dab_align() handles the following data aborts: 521 * 522 * FAULT_ALIGN_0 - Alignment fault 523 * FAULT_ALIGN_0 - Alignment fault 524 * 525 * These faults are fatal if they happen in kernel mode. Otherwise, we 526 * deliver a bus error to the process. 527 */ 528static int 529dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 530{ 531 532 /* Alignment faults are always fatal if they occur in kernel mode */ 533 if (!TRAP_USERMODE(tf)) { 534 if (!td || !td->td_pcb->pcb_onfault) 535 dab_fatal(tf, fsr, far, td, ksig); 536 tf->tf_r0 = EFAULT; 537 tf->tf_pc = (int)td->td_pcb->pcb_onfault; 538 return (0); 539 } 540 541 /* pcb_onfault *must* be NULL at this point */ 542 543 /* See if the cpu state needs to be fixed up */ 544 (void) data_abort_fixup(tf, fsr, far, td, ksig); 545 546 /* Deliver a bus error signal to the process */ 547 ksig->code = 0; 548 ksig->signb = SIGBUS; 549 td->td_frame = tf; 550 551 return (1); 552} 553 554/* 555 * dab_buserr() handles the following data aborts: 556 * 557 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 558 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 559 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 560 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 561 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 562 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 563 * 564 * If pcb_onfault is set, flag the fault and return to the handler. 565 * If the fault occurred in user mode, give the process a SIGBUS. 566 * 567 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 568 * can be flagged as imprecise in the FSR. This causes a real headache 569 * since some of the machine state is lost. In this case, tf->tf_pc 570 * may not actually point to the offending instruction. In fact, if 571 * we've taken a double abort fault, it generally points somewhere near 572 * the top of "data_abort_entry" in exception.S. 573 * 574 * In all other cases, these data aborts are considered fatal. 575 */ 576static int 577dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 578{ 579 struct pcb *pcb = td->td_pcb; 580 581#ifdef __XSCALE__ 582 if ((fsr & FAULT_IMPRECISE) != 0 && 583 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 584 /* 585 * Oops, an imprecise, double abort fault. We've lost the 586 * r14_abt/spsr_abt values corresponding to the original 587 * abort, and the spsr saved in the trapframe indicates 588 * ABT mode. 589 */ 590 tf->tf_spsr &= ~PSR_MODE; 591 592 /* 593 * We use a simple heuristic to determine if the double abort 594 * happened as a result of a kernel or user mode access. 595 * If the current trapframe is at the top of the kernel stack, 596 * the fault _must_ have come from user mode. 597 */ 598 if (tf != ((trapframe_t *)pcb->un_32.pcb32_sp) - 1) { 599 /* 600 * Kernel mode. We're either about to die a 601 * spectacular death, or pcb_onfault will come 602 * to our rescue. Either way, the current value 603 * of tf->tf_pc is irrelevant. 604 */ 605 tf->tf_spsr |= PSR_SVC32_MODE; 606 if (pcb->pcb_onfault == NULL) 607 printf("\nKernel mode double abort!\n"); 608 } else { 609 /* 610 * User mode. We've lost the program counter at the 611 * time of the fault (not that it was accurate anyway; 612 * it's not called an imprecise fault for nothing). 613 * About all we can do is copy r14_usr to tf_pc and 614 * hope for the best. The process is about to get a 615 * SIGBUS, so it's probably history anyway. 616 */ 617 tf->tf_spsr |= PSR_USR32_MODE; 618 tf->tf_pc = tf->tf_usr_lr; 619 } 620 } 621 622 /* FAR is invalid for imprecise exceptions */ 623 if ((fsr & FAULT_IMPRECISE) != 0) 624 far = 0; 625#endif /* __XSCALE__ */ 626 627 if (pcb->pcb_onfault) { 628 tf->tf_r0 = EFAULT; 629 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 630 return (0); 631 } 632 633 /* See if the cpu state needs to be fixed up */ 634 (void) data_abort_fixup(tf, fsr, far, td, ksig); 635 636 /* 637 * At this point, if the fault happened in kernel mode, we're toast 638 */ 639 if (!TRAP_USERMODE(tf)) 640 dab_fatal(tf, fsr, far, td, ksig); 641 642 /* Deliver a bus error signal to the process */ 643 ksig->signb = SIGBUS; 644 ksig->code = 0; 645 td->td_frame = tf; 646 647 return (1); 648} 649 650static __inline int 651prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig) 652{ 653#ifdef CPU_ABORT_FIXUP_REQUIRED 654 int error; 655 656 /* Call the cpu specific prefetch abort fixup routine */ 657 error = cpu_prefetchabt_fixup(tf); 658 if (__predict_true(error != ABORT_FIXUP_FAILED)) 659 return (error); 660 661 /* 662 * Oops, couldn't fix up the instruction 663 */ 664 printf( 665 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n", 666 TRAP_USERMODE(tf) ? "user" : "kernel"); 667 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 668 *((u_int *)tf->tf_pc)); 669 disassemble(tf->tf_pc); 670 671 /* Die now if this happened in kernel mode */ 672 if (!TRAP_USERMODE(tf)) 673 dab_fatal(tf, 0, tf->tf_pc, NULL, ksig); 674 675 return (error); 676#else 677 return (ABORT_FIXUP_OK); 678#endif /* CPU_ABORT_FIXUP_REQUIRED */ 679} 680 681/* 682 * void prefetch_abort_handler(trapframe_t *tf) 683 * 684 * Abort handler called when instruction execution occurs at 685 * a non existent or restricted (access permissions) memory page. 686 * If the address is invalid and we were in SVC mode then panic as 687 * the kernel should never prefetch abort. 688 * If the address is invalid and the page is mapped then the user process 689 * does no have read permission so send it a signal. 690 * Otherwise fault the page in and try again. 691 */ 692void 693prefetch_abort_handler(trapframe_t *tf) 694{ 695 struct thread *td; 696 struct proc * p; 697 struct vm_map *map; 698 vm_offset_t fault_pc, va; 699 int error = 0; 700 u_int sticks = 0; 701 struct ksig ksig; 702 703 704#if 0 705 /* Update vmmeter statistics */ 706 uvmexp.traps++; 707#endif 708#if 0 709 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, 710 (void*)tf->tf_usr_lr); 711#endif 712 713 td = curthread; 714 p = td->td_proc; 715 atomic_add_int(&cnt.v_trap, 1); 716 717 if (TRAP_USERMODE(tf)) { 718 td->td_frame = tf; 719 if (td->td_ucred != td->td_proc->p_ucred) 720 cred_update_thread(td); 721 if (td->td_proc->p_flag & P_SA) 722 thread_user_enter(td); 723 } 724 fault_pc = tf->tf_pc; 725 if (td->td_critnest == 0 && 726 __predict_true((tf->tf_spsr & I32_bit) == 0)) 727 enable_interrupts(I32_bit); 728 729 730 /* See if the cpu state needs to be fixed up */ 731 switch (prefetch_abort_fixup(tf, &ksig)) { 732 case ABORT_FIXUP_RETURN: 733 return; 734 case ABORT_FIXUP_FAILED: 735 /* Deliver a SIGILL to the process */ 736 ksig.signb = SIGILL; 737 ksig.code = 0; 738 td->td_frame = tf; 739 goto do_trapsignal; 740 default: 741 break; 742 } 743 744 /* Prefetch aborts cannot happen in kernel mode */ 745 if (__predict_false(!TRAP_USERMODE(tf))) 746 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); 747 sticks = td->td_sticks; 748 749 750 /* Ok validate the address, can only execute in USER space */ 751 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 752 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 753 ksig.signb = SIGSEGV; 754 ksig.code = 0; 755 goto do_trapsignal; 756 } 757 758 map = &td->td_proc->p_vmspace->vm_map; 759 va = trunc_page(fault_pc); 760 761 /* 762 * See if the pmap can handle this fault on its own... 763 */ 764#ifdef DEBUG 765 last_fault_code = -1; 766#endif 767 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) 768 goto out; 769 770 if (map != kernel_map) { 771 PROC_LOCK(p); 772 p->p_lock++; 773 PROC_UNLOCK(p); 774 } 775 776 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, 777 VM_FAULT_NORMAL); 778 if (map != kernel_map) { 779 PROC_LOCK(p); 780 p->p_lock--; 781 PROC_UNLOCK(p); 782 } 783 784 if (__predict_true(error == 0)) 785 goto out; 786 787 if (error == ENOMEM) { 788 printf("VM: pid %d (%s), uid %d killed: " 789 "out of swap\n", td->td_proc->p_pid, td->td_proc->p_comm, 790 (td->td_proc->p_ucred) ? 791 td->td_proc->p_ucred->cr_uid : -1); 792 ksig.signb = SIGKILL; 793 } else { 794 ksig.signb = SIGSEGV; 795 } 796 ksig.code = 0; 797 798do_trapsignal: 799 call_trapsignal(td, ksig.signb, ksig.code); 800 801out: 802 userret(td, tf, sticks); 803 804} 805 806extern int badaddr_read_1(const uint8_t *, uint8_t *); 807extern int badaddr_read_2(const uint16_t *, uint16_t *); 808extern int badaddr_read_4(const uint32_t *, uint32_t *); 809/* 810 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 811 * If the read succeeds, the value is written to 'rptr' and zero is returned. 812 * Else, return EFAULT. 813 */ 814int 815badaddr_read(void *addr, size_t size, void *rptr) 816{ 817 union { 818 uint8_t v1; 819 uint16_t v2; 820 uint32_t v4; 821 } u; 822 int rv; 823 824 cpu_drain_writebuf(); 825 826 /* Read from the test address. */ 827 switch (size) { 828 case sizeof(uint8_t): 829 rv = badaddr_read_1(addr, &u.v1); 830 if (rv == 0 && rptr) 831 *(uint8_t *) rptr = u.v1; 832 break; 833 834 case sizeof(uint16_t): 835 rv = badaddr_read_2(addr, &u.v2); 836 if (rv == 0 && rptr) 837 *(uint16_t *) rptr = u.v2; 838 break; 839 840 case sizeof(uint32_t): 841 rv = badaddr_read_4(addr, &u.v4); 842 if (rv == 0 && rptr) 843 *(uint32_t *) rptr = u.v4; 844 break; 845 846 default: 847 panic("badaddr: invalid size (%lu)", (u_long) size); 848 } 849 850 /* Return EFAULT if the address was invalid, else zero */ 851 return (rv); 852} 853 854#define MAXARGS 8 855static void 856syscall(struct thread *td, trapframe_t *frame, u_int32_t insn) 857{ 858 struct proc *p = td->td_proc; 859 int code, error; 860 u_int nap, nargs; 861 register_t *ap, *args, copyargs[MAXARGS]; 862 struct sysent *callp; 863 int locked = 0; 864 u_int sticks = 0; 865 866 atomic_add_int(&cnt.v_syscall, 1); 867 sticks = td->td_sticks; 868 if (td->td_ucred != td->td_proc->p_ucred) 869 cred_update_thread(td); 870 switch (insn & SWI_OS_MASK) { 871 case 0: /* XXX: we need our own one. */ 872 nap = 4; 873 break; 874 default: 875 trapsignal(td, SIGILL, 0); 876 userret(td, frame, td->td_sticks); 877 return; 878 } 879 code = insn & 0x000fffff; 880 sticks = td->td_sticks; 881 ap = &frame->tf_r0; 882 if (code == SYS_syscall) { 883 code = *ap++; 884 885 nap--; 886 } else if (code == SYS___syscall) { 887 code = *ap++; 888 nap -= 2; 889 ap++; 890 } 891 if (p->p_sysent->sv_mask) 892 code &= p->p_sysent->sv_mask; 893 if (code >= p->p_sysent->sv_size) 894 callp = &p->p_sysent->sv_table[0]; 895 else 896 callp = &p->p_sysent->sv_table[code]; 897 nargs = callp->sy_narg & SYF_ARGMASK; 898 memcpy(copyargs, ap, nap * sizeof(register_t)); 899 if (nargs > nap) { 900 error = copyin((void *)frame->tf_usr_sp, copyargs + nap, 901 (nargs - nap) * sizeof(register_t)); 902 if (error) 903 goto bad; 904 } 905 args = copyargs; 906 error = 0; 907#ifdef KTRACE 908 if (KTRPOINT(td, KTR_SYSCALL)) 909 ktrsyscall(code, nargs, args); 910#endif 911 912 if ((callp->sy_narg & SYF_MPSAFE) == 0) 913 mtx_lock(&Giant); 914 locked = 1; 915 if (error == 0) { 916 td->td_retval[0] = 0; 917 td->td_retval[1] = 0; 918 error = (*callp->sy_call)(td, args); 919 } 920 switch (error) { 921 case 0: 922 frame->tf_r0 = td->td_retval[0]; 923 frame->tf_r1 = td->td_retval[1]; 924 925 frame->tf_spsr &= ~PSR_C_bit; /* carry bit */ 926 break; 927 928 case ERESTART: 929 /* 930 * Reconstruct the pc to point at the swi. 931 */ 932 frame->tf_pc -= INSN_SIZE; 933 break; 934 case EJUSTRETURN: 935 /* nothing to do */ 936 break; 937 default: 938bad: 939 frame->tf_r0 = error; 940 frame->tf_spsr |= PSR_C_bit; /* carry bit */ 941 break; 942 } 943 if (locked && (callp->sy_narg & SYF_MPSAFE) == 0) 944 mtx_unlock(&Giant); 945 946 947 userret(td, frame, sticks); 948#ifdef KTRACE 949 if (KTRPOINT(td, KTR_SYSRET)) 950 ktrsysret(code, error, td->td_retval[0]); 951#endif 952 mtx_assert(&sched_lock, MA_NOTOWNED); 953 mtx_assert(&Giant, MA_NOTOWNED); 954} 955 956void 957swi_handler(trapframe_t *frame) 958{ 959 struct thread *td = curthread; 960 uint32_t insn; 961 962 td->td_frame = frame; 963 964 if (td->td_proc->p_flag & P_SA) 965 thread_user_enter(td); 966 /* 967 * Make sure the program counter is correctly aligned so we 968 * don't take an alignment fault trying to read the opcode. 969 */ 970 if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) { 971 trapsignal(td, SIGILL, 0); 972 userret(td, frame, td->td_sticks); 973 return; 974 } 975 insn = *(u_int32_t *)(frame->tf_pc - INSN_SIZE); 976 /* 977 * Enable interrupts if they were enabled before the exception. 978 * Since all syscalls *should* come from user mode it will always 979 * be safe to enable them, but check anyway. 980 */ 981 if (td->td_critnest == 0 && !(frame->tf_spsr & I32_bit)) 982 enable_interrupts(I32_bit); 983 984 syscall(td, frame, insn); 985} 986 987