syscall.c revision 135656
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 135656 2004-09-23 22:22:33Z cognet $"); 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/user.h> 93#include <sys/kernel.h> 94#include <sys/lock.h> 95#include <sys/mutex.h> 96#include <sys/syscall.h> 97#include <sys/sysent.h> 98#ifdef KTRACE 99#include <sys/uio.h> 100#include <sys/ktrace.h> 101#endif 102 103#include <vm/vm.h> 104#include <vm/pmap.h> 105#include <vm/vm_kern.h> 106#include <vm/vm_map.h> 107#include <vm/vm_extern.h> 108 109#include <machine/cpuconf.h> 110#include <machine/vmparam.h> 111#include <machine/frame.h> 112#include <machine/katelib.h> 113#include <machine/cpu.h> 114#include <machine/intr.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 218extern int curpid; 219void 220data_abort_handler(trapframe_t *tf) 221{ 222 struct vm_map *map; 223 struct pcb *pcb; 224 struct thread *td; 225 u_int user, far, fsr; 226 vm_prot_t ftype; 227 void *onfault; 228 vm_offset_t va; 229 u_int sticks = 0; 230 int error = 0; 231 struct ksig ksig; 232 233 /* Grab FAR/FSR before enabling interrupts */ 234 far = cpu_faultaddress(); 235 fsr = cpu_faultstatus(); 236#if 0 237 printf("data abort: %p (from %p %p)\n", (void*)far, (void*)tf->tf_pc, 238 (void*)tf->tf_svc_lr); 239#endif 240 241 /* Update vmmeter statistics */ 242#if 0 243 vmexp.traps++; 244#endif 245 246 td = curthread; 247 248 /* Data abort came from user mode? */ 249 user = TRAP_USERMODE(tf); 250 251 if (user) { 252 if (td->td_ucred != td->td_proc->p_ucred) 253 cred_update_thread(td); 254 255 } 256 /* Grab the current pcb */ 257 pcb = td->td_pcb; 258 /* Re-enable interrupts if they were enabled previously */ 259 if (td->td_critnest == 0 && __predict_true(tf->tf_spsr & I32_bit) == 0) 260 enable_interrupts(I32_bit); 261 262 /* Invoke the appropriate handler, if necessary */ 263 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 264 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 265 td, &ksig)) { 266 goto do_trapsignal; 267 } 268 goto out; 269 } 270 271 /* 272 * At this point, we're dealing with one of the following data aborts: 273 * 274 * FAULT_TRANS_S - Translation -- Section 275 * FAULT_TRANS_P - Translation -- Page 276 * FAULT_DOMAIN_S - Domain -- Section 277 * FAULT_DOMAIN_P - Domain -- Page 278 * FAULT_PERM_S - Permission -- Section 279 * FAULT_PERM_P - Permission -- Page 280 * 281 * These are the main virtual memory-related faults signalled by 282 * the MMU. 283 */ 284 285 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 286 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 287 tf->tf_r0 = EFAULT; 288 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 289 return; 290 } 291 292 if (user) { 293 sticks = td->td_sticks; 294 td->td_frame = tf; 295 } 296 /* 297 * Make sure the Program Counter is sane. We could fall foul of 298 * someone executing Thumb code, in which case the PC might not 299 * be word-aligned. This would cause a kernel alignment fault 300 * further down if we have to decode the current instruction. 301 * XXX: It would be nice to be able to support Thumb at some point. 302 */ 303 if (__predict_false((tf->tf_pc & 3) != 0)) { 304 if (user) { 305 /* 306 * Give the user an illegal instruction signal. 307 */ 308 /* Deliver a SIGILL to the process */ 309 ksig.signb = SIGILL; 310 ksig.code = 0; 311 goto do_trapsignal; 312 } 313 314 /* 315 * The kernel never executes Thumb code. 316 */ 317 printf("\ndata_abort_fault: Misaligned Kernel-mode " 318 "Program Counter\n"); 319 dab_fatal(tf, fsr, far, td, &ksig); 320 } 321 322 /* See if the cpu state needs to be fixed up */ 323 switch (data_abort_fixup(tf, fsr, far, td, &ksig)) { 324 case ABORT_FIXUP_RETURN: 325 return; 326 case ABORT_FIXUP_FAILED: 327 /* Deliver a SIGILL to the process */ 328 ksig.signb = SIGILL; 329 ksig.code = 0; 330 goto do_trapsignal; 331 default: 332 break; 333 } 334 335 va = trunc_page((vm_offset_t)far); 336 337 /* 338 * It is only a kernel address space fault iff: 339 * 1. user == 0 and 340 * 2. pcb_onfault not set or 341 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 342 */ 343 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 344 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 345 __predict_true((pcb->pcb_onfault == NULL || 346 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 347 map = kernel_map; 348 349 /* Was the fault due to the FPE/IPKDB ? */ 350 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 351 352 /* 353 * Force exit via userret() 354 * This is necessary as the FPE is an extension to 355 * userland that actually runs in a priveledged mode 356 * but uses USR mode permissions for its accesses. 357 */ 358 user = 1; 359 ksig.signb = SIGSEGV; 360 ksig.code = 0; 361 goto do_trapsignal; 362 } 363 } else { 364 map = &td->td_proc->p_vmspace->vm_map; 365 } 366 367 /* 368 * We need to know whether the page should be mapped 369 * as R or R/W. The MMU does not give us the info as 370 * to whether the fault was caused by a read or a write. 371 * 372 * However, we know that a permission fault can only be 373 * the result of a write to a read-only location, so 374 * we can deal with those quickly. 375 * 376 * Otherwise we need to disassemble the instruction 377 * responsible to determine if it was a write. 378 */ 379 if (IS_PERMISSION_FAULT(fsr)) { 380 ftype = VM_PROT_WRITE; 381 } else { 382 u_int insn = ReadWord(tf->tf_pc); 383 384 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */ 385 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */ 386 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT */ 387 { 388 ftype = VM_PROT_WRITE; 389 } 390 else 391 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */ 392 ftype = VM_PROT_READ | VM_PROT_WRITE; 393 else 394 ftype = VM_PROT_READ; 395 } 396 397 /* 398 * See if the fault is as a result of ref/mod emulation, 399 * or domain mismatch. 400 */ 401#ifdef DEBUG 402 last_fault_code = fsr; 403#endif 404 if (pmap_fault_fixup(user ? vmspace_pmap(td->td_proc->p_vmspace) : 405 kernel_pmap, va, ftype, user)) { 406 goto out; 407 } 408 409 onfault = pcb->pcb_onfault; 410 pcb->pcb_onfault = NULL; 411 error = vm_fault(map, va, ftype, (ftype & VM_PROT_WRITE) ? 412 VM_FAULT_DIRTY : VM_FAULT_NORMAL); 413 pcb->pcb_onfault = onfault; 414 if (__predict_true(error == 0)) { 415 goto out; 416 } 417 418 if (user == 0) { 419 if (pcb->pcb_onfault) { 420 tf->tf_r0 = error; 421 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 422 return; 423 } 424 425 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype, 426 error); 427 dab_fatal(tf, fsr, far, td, &ksig); 428 } 429 430 431 if (error == ENOMEM) { 432 printf("VM: pid %d (%s), uid %d killed: " 433 "out of swap\n", td->td_proc->p_pid, td->td_proc->p_comm, 434 (td->td_proc->p_ucred) ? 435 td->td_proc->p_ucred->cr_uid : -1); 436 ksig.signb = SIGKILL; 437 } else { 438 ksig.signb = SIGSEGV; 439 } 440 ksig.code = 0; 441do_trapsignal: 442 call_trapsignal(td, ksig.signb, ksig.code); 443out: 444 /* If returning to user mode, make sure to invoke userret() */ 445 if (user) 446 userret(td, tf, sticks); 447} 448 449/* 450 * dab_fatal() handles the following data aborts: 451 * 452 * FAULT_WRTBUF_0 - Vector Exception 453 * FAULT_WRTBUF_1 - Terminal Exception 454 * 455 * We should never see these on a properly functioning system. 456 * 457 * This function is also called by the other handlers if they 458 * detect a fatal problem. 459 * 460 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 461 */ 462static int 463dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 464{ 465 const char *mode; 466 467 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 468 469 if (td != NULL) { 470 printf("Fatal %s mode data abort: '%s'\n", mode, 471 data_aborts[fsr & FAULT_TYPE_MASK].desc); 472 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 473 if ((fsr & FAULT_IMPRECISE) == 0) 474 printf("%08x, ", far); 475 else 476 printf("Invalid, "); 477 printf("spsr=%08x\n", tf->tf_spsr); 478 } else { 479 printf("Fatal %s mode prefetch abort at 0x%08x\n", 480 mode, tf->tf_pc); 481 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 482 } 483 484 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 485 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 486 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 487 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 488 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 489 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 490 printf("r12=%08x, ", tf->tf_r12); 491 492 if (TRAP_USERMODE(tf)) 493 printf("usp=%08x, ulr=%08x", 494 tf->tf_usr_sp, tf->tf_usr_lr); 495 else 496 printf("ssp=%08x, slr=%08x", 497 tf->tf_svc_sp, tf->tf_svc_lr); 498 printf(", pc =%08x\n\n", tf->tf_pc); 499 500#if defined(DDB) || defined(KGDB) 501 kdb_trap(T_FAULT, tf); 502#endif 503 panic("Fatal abort"); 504 /*NOTREACHED*/ 505} 506 507/* 508 * dab_align() handles the following data aborts: 509 * 510 * FAULT_ALIGN_0 - Alignment fault 511 * FAULT_ALIGN_0 - Alignment fault 512 * 513 * These faults are fatal if they happen in kernel mode. Otherwise, we 514 * deliver a bus error to the process. 515 */ 516static int 517dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 518{ 519 520 /* Alignment faults are always fatal if they occur in kernel mode */ 521 if (!TRAP_USERMODE(tf)) 522 dab_fatal(tf, fsr, far, td, ksig); 523 524 /* pcb_onfault *must* be NULL at this point */ 525 526 /* See if the cpu state needs to be fixed up */ 527 (void) data_abort_fixup(tf, fsr, far, td, ksig); 528 529 /* Deliver a bus error signal to the process */ 530 ksig->code = 0; 531 ksig->signb = SIGBUS; 532 td->td_frame = tf; 533 534 return (1); 535} 536 537/* 538 * dab_buserr() handles the following data aborts: 539 * 540 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 541 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 542 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 543 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 544 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 545 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 546 * 547 * If pcb_onfault is set, flag the fault and return to the handler. 548 * If the fault occurred in user mode, give the process a SIGBUS. 549 * 550 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 551 * can be flagged as imprecise in the FSR. This causes a real headache 552 * since some of the machine state is lost. In this case, tf->tf_pc 553 * may not actually point to the offending instruction. In fact, if 554 * we've taken a double abort fault, it generally points somewhere near 555 * the top of "data_abort_entry" in exception.S. 556 * 557 * In all other cases, these data aborts are considered fatal. 558 */ 559static int 560dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 561{ 562 struct pcb *pcb = td->td_pcb; 563 564#ifdef __XSCALE__ 565 if ((fsr & FAULT_IMPRECISE) != 0 && 566 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 567 /* 568 * Oops, an imprecise, double abort fault. We've lost the 569 * r14_abt/spsr_abt values corresponding to the original 570 * abort, and the spsr saved in the trapframe indicates 571 * ABT mode. 572 */ 573 tf->tf_spsr &= ~PSR_MODE; 574 575 /* 576 * We use a simple heuristic to determine if the double abort 577 * happened as a result of a kernel or user mode access. 578 * If the current trapframe is at the top of the kernel stack, 579 * the fault _must_ have come from user mode. 580 */ 581 if (tf != ((trapframe_t *)pcb->un_32.pcb32_sp) - 1) { 582 /* 583 * Kernel mode. We're either about to die a 584 * spectacular death, or pcb_onfault will come 585 * to our rescue. Either way, the current value 586 * of tf->tf_pc is irrelevant. 587 */ 588 tf->tf_spsr |= PSR_SVC32_MODE; 589 if (pcb->pcb_onfault == NULL) 590 printf("\nKernel mode double abort!\n"); 591 } else { 592 /* 593 * User mode. We've lost the program counter at the 594 * time of the fault (not that it was accurate anyway; 595 * it's not called an imprecise fault for nothing). 596 * About all we can do is copy r14_usr to tf_pc and 597 * hope for the best. The process is about to get a 598 * SIGBUS, so it's probably history anyway. 599 */ 600 tf->tf_spsr |= PSR_USR32_MODE; 601 tf->tf_pc = tf->tf_usr_lr; 602 } 603 } 604 605 /* FAR is invalid for imprecise exceptions */ 606 if ((fsr & FAULT_IMPRECISE) != 0) 607 far = 0; 608#endif /* __XSCALE__ */ 609 610 if (pcb->pcb_onfault) { 611 tf->tf_r0 = EFAULT; 612 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 613 return (0); 614 } 615 616 /* See if the cpu state needs to be fixed up */ 617 (void) data_abort_fixup(tf, fsr, far, td, ksig); 618 619 /* 620 * At this point, if the fault happened in kernel mode, we're toast 621 */ 622 if (!TRAP_USERMODE(tf)) 623 dab_fatal(tf, fsr, far, td, ksig); 624 625 /* Deliver a bus error signal to the process */ 626 ksig->signb = SIGBUS; 627 ksig->code = 0; 628 td->td_frame = tf; 629 630 return (1); 631} 632 633static __inline int 634prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig) 635{ 636#ifdef CPU_ABORT_FIXUP_REQUIRED 637 int error; 638 639 /* Call the cpu specific prefetch abort fixup routine */ 640 error = cpu_prefetchabt_fixup(tf); 641 if (__predict_true(error != ABORT_FIXUP_FAILED)) 642 return (error); 643 644 /* 645 * Oops, couldn't fix up the instruction 646 */ 647 printf( 648 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n", 649 TRAP_USERMODE(tf) ? "user" : "kernel"); 650 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 651 *((u_int *)tf->tf_pc)); 652 disassemble(tf->tf_pc); 653 654 /* Die now if this happened in kernel mode */ 655 if (!TRAP_USERMODE(tf)) 656 dab_fatal(tf, 0, tf->tf_pc, NULL, ksig); 657 658 return (error); 659#else 660 return (ABORT_FIXUP_OK); 661#endif /* CPU_ABORT_FIXUP_REQUIRED */ 662} 663 664/* 665 * void prefetch_abort_handler(trapframe_t *tf) 666 * 667 * Abort handler called when instruction execution occurs at 668 * a non existent or restricted (access permissions) memory page. 669 * If the address is invalid and we were in SVC mode then panic as 670 * the kernel should never prefetch abort. 671 * If the address is invalid and the page is mapped then the user process 672 * does no have read permission so send it a signal. 673 * Otherwise fault the page in and try again. 674 */ 675void 676prefetch_abort_handler(trapframe_t *tf) 677{ 678 struct thread *td; 679 struct vm_map *map; 680 vm_offset_t fault_pc, va; 681 int error = 0; 682 u_int sticks = 0; 683 struct ksig ksig; 684 685#if 0 686 /* Update vmmeter statistics */ 687 uvmexp.traps++; 688#endif 689#if 0 690 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, 691 (void*)tf->tf_usr_lr); 692#endif 693 694 td = curthread; 695 696 if (TRAP_USERMODE(tf)) { 697 if (td->td_ucred != td->td_proc->p_ucred) 698 cred_update_thread(td); 699 700 } 701 fault_pc = tf->tf_pc; 702 if (td->td_critnest == 0 && 703 __predict_true((tf->tf_spsr & I32_bit) == 0)) 704 enable_interrupts(I32_bit); 705 706 707 /* See if the cpu state needs to be fixed up */ 708 switch (prefetch_abort_fixup(tf, &ksig)) { 709 case ABORT_FIXUP_RETURN: 710 return; 711 case ABORT_FIXUP_FAILED: 712 /* Deliver a SIGILL to the process */ 713 ksig.signb = SIGILL; 714 ksig.code = 0; 715 td->td_frame = tf; 716 goto do_trapsignal; 717 default: 718 break; 719 } 720 721 /* Prefetch aborts cannot happen in kernel mode */ 722 if (__predict_false(!TRAP_USERMODE(tf))) 723 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); 724 /* Get fault address */ 725 td->td_frame = tf; 726 sticks = td->td_sticks; 727 728 729 /* Ok validate the address, can only execute in USER space */ 730 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 731 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 732 ksig.signb = SIGSEGV; 733 ksig.code = 0; 734 goto do_trapsignal; 735 } 736 737 map = &td->td_proc->p_vmspace->vm_map; 738 va = trunc_page(fault_pc); 739 740 /* 741 * See if the pmap can handle this fault on its own... 742 */ 743#ifdef DEBUG 744 last_fault_code = -1; 745#endif 746 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) 747 goto out; 748 749 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, 750 VM_FAULT_NORMAL); 751 if (__predict_true(error == 0)) 752 goto out; 753 754 if (error == ENOMEM) { 755 printf("VM: pid %d (%s), uid %d killed: " 756 "out of swap\n", td->td_proc->p_pid, td->td_proc->p_comm, 757 (td->td_proc->p_ucred) ? 758 td->td_proc->p_ucred->cr_uid : -1); 759 ksig.signb = SIGKILL; 760 } else { 761 ksig.signb = SIGSEGV; 762 } 763 ksig.code = 0; 764 765do_trapsignal: 766 call_trapsignal(td, ksig.signb, ksig.code); 767 768out: 769 userret(td, tf, sticks); 770 771} 772 773extern int badaddr_read_1(const uint8_t *, uint8_t *); 774extern int badaddr_read_2(const uint16_t *, uint16_t *); 775extern int badaddr_read_4(const uint32_t *, uint32_t *); 776/* 777 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 778 * If the read succeeds, the value is written to 'rptr' and zero is returned. 779 * Else, return EFAULT. 780 */ 781int 782badaddr_read(void *addr, size_t size, void *rptr) 783{ 784 union { 785 uint8_t v1; 786 uint16_t v2; 787 uint32_t v4; 788 } u; 789 int rv; 790 791 cpu_drain_writebuf(); 792 793 /* Read from the test address. */ 794 switch (size) { 795 case sizeof(uint8_t): 796 rv = badaddr_read_1(addr, &u.v1); 797 if (rv == 0 && rptr) 798 *(uint8_t *) rptr = u.v1; 799 break; 800 801 case sizeof(uint16_t): 802 rv = badaddr_read_2(addr, &u.v2); 803 if (rv == 0 && rptr) 804 *(uint16_t *) rptr = u.v2; 805 break; 806 807 case sizeof(uint32_t): 808 rv = badaddr_read_4(addr, &u.v4); 809 if (rv == 0 && rptr) 810 *(uint32_t *) rptr = u.v4; 811 break; 812 813 default: 814 panic("badaddr: invalid size (%lu)", (u_long) size); 815 } 816 817 /* Return EFAULT if the address was invalid, else zero */ 818 return (rv); 819} 820 821#define MAXARGS 8 822static void 823syscall(struct thread *td, trapframe_t *frame, u_int32_t insn) 824{ 825 struct proc *p = td->td_proc; 826 int code, error; 827 u_int nap, nargs; 828 register_t *ap, *args, copyargs[MAXARGS]; 829 struct sysent *callp; 830 int locked = 0; 831 u_int sticks = 0; 832 833 sticks = td->td_sticks; 834 if (td->td_ucred != td->td_proc->p_ucred) 835 cred_update_thread(td); 836 switch (insn & SWI_OS_MASK) { 837 case 0: /* XXX: we need our own one. */ 838 nap = 4; 839 break; 840 default: 841 trapsignal(td, SIGILL, 0); 842 userret(td, frame, td->td_sticks); 843 return; 844 } 845 code = insn & 0x000fffff; 846 sticks = td->td_sticks; 847 ap = &frame->tf_r0; 848 if (code == SYS_syscall) { 849 code = *ap++; 850 851 nap--; 852 } else if (code == SYS___syscall) { 853 code = *ap++; 854 nap -= 2; 855 ap++; 856 } 857 if (p->p_sysent->sv_mask) 858 code &= p->p_sysent->sv_mask; 859 if (code >= p->p_sysent->sv_size) 860 callp = &p->p_sysent->sv_table[0]; 861 else 862 callp = &p->p_sysent->sv_table[code]; 863 nargs = callp->sy_narg & SYF_ARGMASK; 864 if (nargs <= nap) 865 args = ap; 866 else { 867 memcpy(copyargs, ap, nap * sizeof(register_t)); 868 error = copyin((void *)frame->tf_usr_sp, copyargs + nap, 869 (nargs - nap) * sizeof(register_t)); 870 if (error) 871 goto bad; 872 args = copyargs; 873 } 874 error = 0; 875#ifdef KTRACE 876 if (KTRPOINT(td, KTR_SYSCALL)) 877 ktrsyscall(code, nargs, args); 878#endif 879 880 if ((callp->sy_narg & SYF_MPSAFE) == 0) 881 mtx_lock(&Giant); 882 locked = 1; 883 if (error == 0) { 884 td->td_retval[0] = 0; 885 td->td_retval[1] = 0; 886 error = (*callp->sy_call)(td, args); 887 } 888 switch (error) { 889 case 0: 890 frame->tf_r0 = td->td_retval[0]; 891 frame->tf_r1 = td->td_retval[1]; 892 893 frame->tf_spsr &= ~PSR_C_bit; /* carry bit */ 894 break; 895 896 case ERESTART: 897 /* 898 * Reconstruct the pc to point at the swi. 899 */ 900 frame->tf_pc -= INSN_SIZE; 901 break; 902 case EJUSTRETURN: 903 /* nothing to do */ 904 break; 905 default: 906bad: 907 frame->tf_r0 = error; 908 frame->tf_spsr |= PSR_C_bit; /* carry bit */ 909 break; 910 } 911 if (locked && (callp->sy_narg & SYF_MPSAFE) == 0) 912 mtx_unlock(&Giant); 913 914 915 userret(td, frame, sticks); 916#ifdef KTRACE 917 if (KTRPOINT(td, KTR_SYSRET)) 918 ktrsysret(code, error, td->td_retval[0]); 919#endif 920 mtx_assert(&sched_lock, MA_NOTOWNED); 921 mtx_assert(&Giant, MA_NOTOWNED); 922} 923 924void 925swi_handler(trapframe_t *frame) 926{ 927 struct thread *td = curthread; 928 uint32_t insn; 929 930 /* 931 * Enable interrupts if they were enabled before the exception. 932 * Since all syscalls *should* come from user mode it will always 933 * be safe to enable them, but check anyway. 934 */ 935 936 if (td->td_critnest == 0 && !(frame->tf_spsr & I32_bit)) 937 enable_interrupts(I32_bit); 938 /* 939 * Make sure the program counter is correctly aligned so we 940 * don't take an alignment fault trying to read the opcode. 941 */ 942 if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) { 943 trapsignal(td, SIGILL, 0); 944 userret(td, frame, td->td_sticks); 945 return; 946 } 947 insn = *(u_int32_t *)(frame->tf_pc - INSN_SIZE); 948 td->td_frame = frame; 949 syscall(td, frame, insn); 950} 951 952