trap-v4.c revision 144971
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 144971 2005-04-12 23:18:54Z 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#if !defined(DDB) 122#define kdb_trap kgdb_trap 123#endif 124 125 126 127void swi_handler(trapframe_t *); 128void undefinedinstruction(trapframe_t *); 129 130#include <machine/disassem.h> 131#include <machine/machdep.h> 132 133extern char fusubailout[]; 134 135#ifdef DEBUG 136int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 137#endif 138 139#if defined(CPU_ARM3) || defined(CPU_ARM6) || \ 140 defined(CPU_ARM7) || defined(CPU_ARM7TDMI) 141/* These CPUs may need data/prefetch abort fixups */ 142#define CPU_ABORT_FIXUP_REQUIRED 143#endif 144 145struct ksig { 146 int signb; 147 u_long code; 148}; 149struct data_abort { 150 int (*func)(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 151 const char *desc; 152}; 153 154static int dab_fatal(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 155static int dab_align(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 156static int dab_buserr(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 157 158static const struct data_abort data_aborts[] = { 159 {dab_fatal, "Vector Exception"}, 160 {dab_align, "Alignment Fault 1"}, 161 {dab_fatal, "Terminal Exception"}, 162 {dab_align, "Alignment Fault 3"}, 163 {dab_buserr, "External Linefetch Abort (S)"}, 164 {NULL, "Translation Fault (S)"}, 165 {dab_buserr, "External Linefetch Abort (P)"}, 166 {NULL, "Translation Fault (P)"}, 167 {dab_buserr, "External Non-Linefetch Abort (S)"}, 168 {NULL, "Domain Fault (S)"}, 169 {dab_buserr, "External Non-Linefetch Abort (P)"}, 170 {NULL, "Domain Fault (P)"}, 171 {dab_buserr, "External Translation Abort (L1)"}, 172 {NULL, "Permission Fault (S)"}, 173 {dab_buserr, "External Translation Abort (L2)"}, 174 {NULL, "Permission Fault (P)"} 175}; 176 177/* Determine if a fault came from user mode */ 178#define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE) 179 180/* Determine if 'x' is a permission fault */ 181#define IS_PERMISSION_FAULT(x) \ 182 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 183 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 184 185static __inline void 186call_trapsignal(struct thread *td, int sig, u_long code) 187{ 188 189 trapsignal(td, sig, code); 190} 191 192static __inline int 193data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 194{ 195#ifdef CPU_ABORT_FIXUP_REQUIRED 196 int error; 197 198 /* Call the cpu specific data abort fixup routine */ 199 error = cpu_dataabt_fixup(tf); 200 if (__predict_true(error != ABORT_FIXUP_FAILED)) 201 return (error); 202 203 /* 204 * Oops, couldn't fix up the instruction 205 */ 206 printf("data_abort_fixup: fixup for %s mode data abort failed.\n", 207 TRAP_USERMODE(tf) ? "user" : "kernel"); 208 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 209 *((u_int *)tf->tf_pc)); 210 disassemble(tf->tf_pc); 211 212 /* Die now if this happened in kernel mode */ 213 if (!TRAP_USERMODE(tf)) 214 dab_fatal(tf, fsr, far, td, NULL, ksig); 215 216 return (error); 217#else 218 return (ABORT_FIXUP_OK); 219#endif /* CPU_ABORT_FIXUP_REQUIRED */ 220} 221 222void 223data_abort_handler(trapframe_t *tf) 224{ 225 struct vm_map *map; 226 struct pcb *pcb; 227 struct thread *td; 228 u_int user, far, fsr; 229 vm_prot_t ftype; 230 void *onfault; 231 vm_offset_t va; 232 u_int sticks = 0; 233 int error = 0; 234 struct ksig ksig; 235 struct proc *p; 236 237 238 /* Grab FAR/FSR before enabling interrupts */ 239 far = cpu_faultaddress(); 240 fsr = cpu_faultstatus(); 241#if 0 242 printf("data abort: %p (from %p %p)\n", (void*)far, (void*)tf->tf_pc, 243 (void*)tf->tf_svc_lr); 244#endif 245 246 /* Update vmmeter statistics */ 247#if 0 248 vmexp.traps++; 249#endif 250 251 td = curthread; 252 p = td->td_proc; 253 254 PCPU_LAZY_INC(cnt.v_trap); 255 /* Data abort came from user mode? */ 256 user = TRAP_USERMODE(tf); 257 258 if (user) { 259 sticks = td->td_sticks; td->td_frame = tf; 260 if (td->td_ucred != td->td_proc->p_ucred) 261 cred_update_thread(td); 262 if (td->td_pflags & TDP_SA) 263 thread_user_enter(td); 264 265 } 266 /* Grab the current pcb */ 267 pcb = td->td_pcb; 268 /* Re-enable interrupts if they were enabled previously */ 269 if (td->td_critnest == 0 && __predict_true(tf->tf_spsr & I32_bit) == 0) 270 enable_interrupts(I32_bit); 271 272 /* Invoke the appropriate handler, if necessary */ 273 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 274 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 275 td, &ksig)) { 276 goto do_trapsignal; 277 } 278 goto out; 279 } 280 281 /* 282 * At this point, we're dealing with one of the following data aborts: 283 * 284 * FAULT_TRANS_S - Translation -- Section 285 * FAULT_TRANS_P - Translation -- Page 286 * FAULT_DOMAIN_S - Domain -- Section 287 * FAULT_DOMAIN_P - Domain -- Page 288 * FAULT_PERM_S - Permission -- Section 289 * FAULT_PERM_P - Permission -- Page 290 * 291 * These are the main virtual memory-related faults signalled by 292 * the MMU. 293 */ 294 295 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 296 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 297 tf->tf_r0 = EFAULT; 298 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 299 return; 300 } 301 302 /* 303 * Make sure the Program Counter is sane. We could fall foul of 304 * someone executing Thumb code, in which case the PC might not 305 * be word-aligned. This would cause a kernel alignment fault 306 * further down if we have to decode the current instruction. 307 * XXX: It would be nice to be able to support Thumb at some point. 308 */ 309 if (__predict_false((tf->tf_pc & 3) != 0)) { 310 if (user) { 311 /* 312 * Give the user an illegal instruction signal. 313 */ 314 /* Deliver a SIGILL to the process */ 315 ksig.signb = SIGILL; 316 ksig.code = 0; 317 goto do_trapsignal; 318 } 319 320 /* 321 * The kernel never executes Thumb code. 322 */ 323 printf("\ndata_abort_fault: Misaligned Kernel-mode " 324 "Program Counter\n"); 325 dab_fatal(tf, fsr, far, td, &ksig); 326 } 327 328 /* See if the cpu state needs to be fixed up */ 329 switch (data_abort_fixup(tf, fsr, far, td, &ksig)) { 330 case ABORT_FIXUP_RETURN: 331 return; 332 case ABORT_FIXUP_FAILED: 333 /* Deliver a SIGILL to the process */ 334 ksig.signb = SIGILL; 335 ksig.code = 0; 336 goto do_trapsignal; 337 default: 338 break; 339 } 340 341 va = trunc_page((vm_offset_t)far); 342 343 /* 344 * It is only a kernel address space fault iff: 345 * 1. user == 0 and 346 * 2. pcb_onfault not set or 347 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 348 */ 349 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 350 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 351 __predict_true((pcb->pcb_onfault == NULL || 352 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 353 map = kernel_map; 354 355 /* Was the fault due to the FPE/IPKDB ? */ 356 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 357 358 /* 359 * Force exit via userret() 360 * This is necessary as the FPE is an extension to 361 * userland that actually runs in a priveledged mode 362 * but uses USR mode permissions for its accesses. 363 */ 364 user = 1; 365 ksig.signb = SIGSEGV; 366 ksig.code = 0; 367 goto do_trapsignal; 368 } 369 } else { 370 map = &td->td_proc->p_vmspace->vm_map; 371 } 372 373 /* 374 * We need to know whether the page should be mapped 375 * as R or R/W. The MMU does not give us the info as 376 * to whether the fault was caused by a read or a write. 377 * 378 * However, we know that a permission fault can only be 379 * the result of a write to a read-only location, so 380 * we can deal with those quickly. 381 * 382 * Otherwise we need to disassemble the instruction 383 * responsible to determine if it was a write. 384 */ 385 if (IS_PERMISSION_FAULT(fsr)) { 386 ftype = VM_PROT_WRITE; 387 } else { 388 u_int insn = ReadWord(tf->tf_pc); 389 390 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */ 391 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */ 392 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT */ 393 { 394 ftype = VM_PROT_WRITE; 395 } 396 else 397 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */ 398 ftype = VM_PROT_READ | VM_PROT_WRITE; 399 else 400 ftype = VM_PROT_READ; 401 } 402 403 /* 404 * See if the fault is as a result of ref/mod emulation, 405 * or domain mismatch. 406 */ 407#ifdef DEBUG 408 last_fault_code = fsr; 409#endif 410 if (pmap_fault_fixup(user ? vmspace_pmap(td->td_proc->p_vmspace) : 411 kernel_pmap, va, ftype, user)) { 412 goto out; 413 } 414 415 onfault = pcb->pcb_onfault; 416 pcb->pcb_onfault = NULL; 417 if (map != kernel_map) { 418 PROC_LOCK(p); 419 p->p_lock++; 420 PROC_UNLOCK(p); 421 } 422 error = vm_fault(map, va, ftype, (ftype & VM_PROT_WRITE) ? 423 VM_FAULT_DIRTY : VM_FAULT_NORMAL); 424 pcb->pcb_onfault = onfault; 425 if (__predict_true(error == 0)) { 426 goto out; 427 } 428 429 if (map != kernel_map) { 430 PROC_LOCK(p); 431 p->p_lock++; 432 PROC_UNLOCK(p); 433 } 434 if (user == 0) { 435 if (pcb->pcb_onfault) { 436 tf->tf_r0 = error; 437 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 438 return; 439 } 440 441 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype, 442 error); 443 dab_fatal(tf, fsr, far, td, &ksig); 444 } 445 446 447 if (error == ENOMEM) { 448 printf("VM: pid %d (%s), uid %d killed: " 449 "out of swap\n", td->td_proc->p_pid, td->td_proc->p_comm, 450 (td->td_proc->p_ucred) ? 451 td->td_proc->p_ucred->cr_uid : -1); 452 ksig.signb = SIGKILL; 453 } else { 454 ksig.signb = SIGSEGV; 455 } 456 ksig.code = 0; 457do_trapsignal: 458 call_trapsignal(td, ksig.signb, ksig.code); 459out: 460 /* If returning to user mode, make sure to invoke userret() */ 461 if (user) 462 userret(td, tf, sticks); 463} 464 465/* 466 * dab_fatal() handles the following data aborts: 467 * 468 * FAULT_WRTBUF_0 - Vector Exception 469 * FAULT_WRTBUF_1 - Terminal Exception 470 * 471 * We should never see these on a properly functioning system. 472 * 473 * This function is also called by the other handlers if they 474 * detect a fatal problem. 475 * 476 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 477 */ 478static int 479dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 480{ 481 const char *mode; 482 483 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 484 485 if (td != NULL) { 486 printf("Fatal %s mode data abort: '%s'\n", mode, 487 data_aborts[fsr & FAULT_TYPE_MASK].desc); 488 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 489 if ((fsr & FAULT_IMPRECISE) == 0) 490 printf("%08x, ", far); 491 else 492 printf("Invalid, "); 493 printf("spsr=%08x\n", tf->tf_spsr); 494 } else { 495 printf("Fatal %s mode prefetch abort at 0x%08x\n", 496 mode, tf->tf_pc); 497 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 498 } 499 500 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 501 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 502 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 503 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 504 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 505 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 506 printf("r12=%08x, ", tf->tf_r12); 507 508 if (TRAP_USERMODE(tf)) 509 printf("usp=%08x, ulr=%08x", 510 tf->tf_usr_sp, tf->tf_usr_lr); 511 else 512 printf("ssp=%08x, slr=%08x", 513 tf->tf_svc_sp, tf->tf_svc_lr); 514 printf(", pc =%08x\n\n", tf->tf_pc); 515 516#if defined(DDB) || defined(KGDB) 517 kdb_trap(T_FAULT, tf); 518#endif 519 panic("Fatal abort"); 520 /*NOTREACHED*/ 521} 522 523/* 524 * dab_align() handles the following data aborts: 525 * 526 * FAULT_ALIGN_0 - Alignment fault 527 * FAULT_ALIGN_0 - Alignment fault 528 * 529 * These faults are fatal if they happen in kernel mode. Otherwise, we 530 * deliver a bus error to the process. 531 */ 532static int 533dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 534{ 535 536 /* Alignment faults are always fatal if they occur in kernel mode */ 537 if (!TRAP_USERMODE(tf)) { 538 if (!td || !td->td_pcb->pcb_onfault) 539 dab_fatal(tf, fsr, far, td, ksig); 540 tf->tf_r0 = EFAULT; 541 tf->tf_pc = (int)td->td_pcb->pcb_onfault; 542 return (0); 543 } 544 545 /* pcb_onfault *must* be NULL at this point */ 546 547 /* See if the cpu state needs to be fixed up */ 548 (void) data_abort_fixup(tf, fsr, far, td, ksig); 549 550 /* Deliver a bus error signal to the process */ 551 ksig->code = 0; 552 ksig->signb = SIGBUS; 553 td->td_frame = tf; 554 555 return (1); 556} 557 558/* 559 * dab_buserr() handles the following data aborts: 560 * 561 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 562 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 563 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 564 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 565 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 566 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 567 * 568 * If pcb_onfault is set, flag the fault and return to the handler. 569 * If the fault occurred in user mode, give the process a SIGBUS. 570 * 571 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 572 * can be flagged as imprecise in the FSR. This causes a real headache 573 * since some of the machine state is lost. In this case, tf->tf_pc 574 * may not actually point to the offending instruction. In fact, if 575 * we've taken a double abort fault, it generally points somewhere near 576 * the top of "data_abort_entry" in exception.S. 577 * 578 * In all other cases, these data aborts are considered fatal. 579 */ 580static int 581dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 582{ 583 struct pcb *pcb = td->td_pcb; 584 585#ifdef __XSCALE__ 586 if ((fsr & FAULT_IMPRECISE) != 0 && 587 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 588 /* 589 * Oops, an imprecise, double abort fault. We've lost the 590 * r14_abt/spsr_abt values corresponding to the original 591 * abort, and the spsr saved in the trapframe indicates 592 * ABT mode. 593 */ 594 tf->tf_spsr &= ~PSR_MODE; 595 596 /* 597 * We use a simple heuristic to determine if the double abort 598 * happened as a result of a kernel or user mode access. 599 * If the current trapframe is at the top of the kernel stack, 600 * the fault _must_ have come from user mode. 601 */ 602 if (tf != ((trapframe_t *)pcb->un_32.pcb32_sp) - 1) { 603 /* 604 * Kernel mode. We're either about to die a 605 * spectacular death, or pcb_onfault will come 606 * to our rescue. Either way, the current value 607 * of tf->tf_pc is irrelevant. 608 */ 609 tf->tf_spsr |= PSR_SVC32_MODE; 610 if (pcb->pcb_onfault == NULL) 611 printf("\nKernel mode double abort!\n"); 612 } else { 613 /* 614 * User mode. We've lost the program counter at the 615 * time of the fault (not that it was accurate anyway; 616 * it's not called an imprecise fault for nothing). 617 * About all we can do is copy r14_usr to tf_pc and 618 * hope for the best. The process is about to get a 619 * SIGBUS, so it's probably history anyway. 620 */ 621 tf->tf_spsr |= PSR_USR32_MODE; 622 tf->tf_pc = tf->tf_usr_lr; 623 } 624 } 625 626 /* FAR is invalid for imprecise exceptions */ 627 if ((fsr & FAULT_IMPRECISE) != 0) 628 far = 0; 629#endif /* __XSCALE__ */ 630 631 if (pcb->pcb_onfault) { 632 tf->tf_r0 = EFAULT; 633 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 634 return (0); 635 } 636 637 /* See if the cpu state needs to be fixed up */ 638 (void) data_abort_fixup(tf, fsr, far, td, ksig); 639 640 /* 641 * At this point, if the fault happened in kernel mode, we're toast 642 */ 643 if (!TRAP_USERMODE(tf)) 644 dab_fatal(tf, fsr, far, td, ksig); 645 646 /* Deliver a bus error signal to the process */ 647 ksig->signb = SIGBUS; 648 ksig->code = 0; 649 td->td_frame = tf; 650 651 return (1); 652} 653 654static __inline int 655prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig) 656{ 657#ifdef CPU_ABORT_FIXUP_REQUIRED 658 int error; 659 660 /* Call the cpu specific prefetch abort fixup routine */ 661 error = cpu_prefetchabt_fixup(tf); 662 if (__predict_true(error != ABORT_FIXUP_FAILED)) 663 return (error); 664 665 /* 666 * Oops, couldn't fix up the instruction 667 */ 668 printf( 669 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n", 670 TRAP_USERMODE(tf) ? "user" : "kernel"); 671 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 672 *((u_int *)tf->tf_pc)); 673 disassemble(tf->tf_pc); 674 675 /* Die now if this happened in kernel mode */ 676 if (!TRAP_USERMODE(tf)) 677 dab_fatal(tf, 0, tf->tf_pc, NULL, ksig); 678 679 return (error); 680#else 681 return (ABORT_FIXUP_OK); 682#endif /* CPU_ABORT_FIXUP_REQUIRED */ 683} 684 685/* 686 * void prefetch_abort_handler(trapframe_t *tf) 687 * 688 * Abort handler called when instruction execution occurs at 689 * a non existent or restricted (access permissions) memory page. 690 * If the address is invalid and we were in SVC mode then panic as 691 * the kernel should never prefetch abort. 692 * If the address is invalid and the page is mapped then the user process 693 * does no have read permission so send it a signal. 694 * Otherwise fault the page in and try again. 695 */ 696void 697prefetch_abort_handler(trapframe_t *tf) 698{ 699 struct thread *td; 700 struct proc * p; 701 struct vm_map *map; 702 vm_offset_t fault_pc, va; 703 int error = 0; 704 u_int sticks = 0; 705 struct ksig ksig; 706 707 708#if 0 709 /* Update vmmeter statistics */ 710 uvmexp.traps++; 711#endif 712#if 0 713 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, 714 (void*)tf->tf_usr_lr); 715#endif 716 717 td = curthread; 718 p = td->td_proc; 719 PCPU_LAZY_INC(cnt.v_trap); 720 721 if (TRAP_USERMODE(tf)) { 722 td->td_frame = tf; 723 if (td->td_ucred != td->td_proc->p_ucred) 724 cred_update_thread(td); 725 if (td->td_proc->p_flag & P_SA) 726 thread_user_enter(td); 727 } 728 fault_pc = tf->tf_pc; 729 if (td->td_critnest == 0 && 730 __predict_true((tf->tf_spsr & I32_bit) == 0)) 731 enable_interrupts(I32_bit); 732 733 734 /* See if the cpu state needs to be fixed up */ 735 switch (prefetch_abort_fixup(tf, &ksig)) { 736 case ABORT_FIXUP_RETURN: 737 return; 738 case ABORT_FIXUP_FAILED: 739 /* Deliver a SIGILL to the process */ 740 ksig.signb = SIGILL; 741 ksig.code = 0; 742 td->td_frame = tf; 743 goto do_trapsignal; 744 default: 745 break; 746 } 747 748 /* Prefetch aborts cannot happen in kernel mode */ 749 if (__predict_false(!TRAP_USERMODE(tf))) 750 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); 751 sticks = td->td_sticks; 752 753 754 /* Ok validate the address, can only execute in USER space */ 755 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 756 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 757 ksig.signb = SIGSEGV; 758 ksig.code = 0; 759 goto do_trapsignal; 760 } 761 762 map = &td->td_proc->p_vmspace->vm_map; 763 va = trunc_page(fault_pc); 764 765 /* 766 * See if the pmap can handle this fault on its own... 767 */ 768#ifdef DEBUG 769 last_fault_code = -1; 770#endif 771 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) 772 goto out; 773 774 if (map != kernel_map) { 775 PROC_LOCK(p); 776 p->p_lock++; 777 PROC_UNLOCK(p); 778 } 779 780 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, 781 VM_FAULT_NORMAL); 782 if (map != kernel_map) { 783 PROC_LOCK(p); 784 p->p_lock--; 785 PROC_UNLOCK(p); 786 } 787 788 if (__predict_true(error == 0)) 789 goto out; 790 791 if (error == ENOMEM) { 792 printf("VM: pid %d (%s), uid %d killed: " 793 "out of swap\n", td->td_proc->p_pid, td->td_proc->p_comm, 794 (td->td_proc->p_ucred) ? 795 td->td_proc->p_ucred->cr_uid : -1); 796 ksig.signb = SIGKILL; 797 } else { 798 ksig.signb = SIGSEGV; 799 } 800 ksig.code = 0; 801 802do_trapsignal: 803 call_trapsignal(td, ksig.signb, ksig.code); 804 805out: 806 userret(td, tf, sticks); 807 808} 809 810extern int badaddr_read_1(const uint8_t *, uint8_t *); 811extern int badaddr_read_2(const uint16_t *, uint16_t *); 812extern int badaddr_read_4(const uint32_t *, uint32_t *); 813/* 814 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 815 * If the read succeeds, the value is written to 'rptr' and zero is returned. 816 * Else, return EFAULT. 817 */ 818int 819badaddr_read(void *addr, size_t size, void *rptr) 820{ 821 union { 822 uint8_t v1; 823 uint16_t v2; 824 uint32_t v4; 825 } u; 826 int rv; 827 828 cpu_drain_writebuf(); 829 830 /* Read from the test address. */ 831 switch (size) { 832 case sizeof(uint8_t): 833 rv = badaddr_read_1(addr, &u.v1); 834 if (rv == 0 && rptr) 835 *(uint8_t *) rptr = u.v1; 836 break; 837 838 case sizeof(uint16_t): 839 rv = badaddr_read_2(addr, &u.v2); 840 if (rv == 0 && rptr) 841 *(uint16_t *) rptr = u.v2; 842 break; 843 844 case sizeof(uint32_t): 845 rv = badaddr_read_4(addr, &u.v4); 846 if (rv == 0 && rptr) 847 *(uint32_t *) rptr = u.v4; 848 break; 849 850 default: 851 panic("badaddr: invalid size (%lu)", (u_long) size); 852 } 853 854 /* Return EFAULT if the address was invalid, else zero */ 855 return (rv); 856} 857 858#define MAXARGS 8 859static void 860syscall(struct thread *td, trapframe_t *frame, u_int32_t insn) 861{ 862 struct proc *p = td->td_proc; 863 int code, error; 864 u_int nap, nargs; 865 register_t *ap, *args, copyargs[MAXARGS]; 866 struct sysent *callp; 867 int locked = 0; 868 u_int sticks = 0; 869 870 PCPU_LAZY_INC(cnt.v_syscall); 871 sticks = td->td_sticks; 872 if (td->td_ucred != td->td_proc->p_ucred) 873 cred_update_thread(td); 874 switch (insn & SWI_OS_MASK) { 875 case 0: /* XXX: we need our own one. */ 876 nap = 4; 877 break; 878 default: 879 trapsignal(td, SIGILL, 0); 880 userret(td, frame, td->td_sticks); 881 return; 882 } 883 code = insn & 0x000fffff; 884 sticks = td->td_sticks; 885 ap = &frame->tf_r0; 886 if (code == SYS_syscall) { 887 code = *ap++; 888 889 nap--; 890 } else if (code == SYS___syscall) { 891 code = *ap++; 892 nap -= 2; 893 ap++; 894 } 895 if (p->p_sysent->sv_mask) 896 code &= p->p_sysent->sv_mask; 897 if (code >= p->p_sysent->sv_size) 898 callp = &p->p_sysent->sv_table[0]; 899 else 900 callp = &p->p_sysent->sv_table[code]; 901 nargs = callp->sy_narg & SYF_ARGMASK; 902 memcpy(copyargs, ap, nap * sizeof(register_t)); 903 if (nargs > nap) { 904 error = copyin((void *)frame->tf_usr_sp, copyargs + nap, 905 (nargs - nap) * sizeof(register_t)); 906 if (error) 907 goto bad; 908 } 909 args = copyargs; 910 error = 0; 911#ifdef KTRACE 912 if (KTRPOINT(td, KTR_SYSCALL)) 913 ktrsyscall(code, nargs, args); 914#endif 915 916 CTR4(KTR_SYSC, "syscall enter thread %p pid %d proc %s code %d", td, 917 td->td_proc->p_pid, td->td_proc->p_comm, code); 918 if ((callp->sy_narg & SYF_MPSAFE) == 0) 919 mtx_lock(&Giant); 920 locked = 1; 921 if (error == 0) { 922 td->td_retval[0] = 0; 923 td->td_retval[1] = 0; 924 STOPEVENT(p, S_SCE, (callp->sy_narg & SYF_ARGMASK)); 925 PTRACESTOP_SC(p, td, S_PT_SCE); 926 error = (*callp->sy_call)(td, args); 927 } 928 switch (error) { 929 case 0: 930#ifdef __ARMEB__ 931 if ((insn & 0x000fffff) && 932 (code != SYS_lseek)) { 933 /* 934 * 64-bit return, 32-bit syscall. Fixup byte order 935 */ 936 frame->tf_r0 = 0; 937 frame->tf_r1 = td->td_retval[0]; 938 } else { 939 frame->tf_r0 = td->td_retval[0]; 940 frame->tf_r1 = td->td_retval[1]; 941 } 942#else 943 frame->tf_r0 = td->td_retval[0]; 944 frame->tf_r1 = td->td_retval[1]; 945#endif 946 frame->tf_spsr &= ~PSR_C_bit; /* carry bit */ 947 break; 948 949 case ERESTART: 950 /* 951 * Reconstruct the pc to point at the swi. 952 */ 953 frame->tf_pc -= INSN_SIZE; 954 break; 955 case EJUSTRETURN: 956 /* nothing to do */ 957 break; 958 default: 959bad: 960 frame->tf_r0 = error; 961 frame->tf_spsr |= PSR_C_bit; /* carry bit */ 962 break; 963 } 964 if (locked && (callp->sy_narg & SYF_MPSAFE) == 0) 965 mtx_unlock(&Giant); 966 967 968 userret(td, frame, sticks); 969 CTR4(KTR_SYSC, "syscall exit thread %p pid %d proc %s code %d", td, 970 td->td_proc->p_pid, td->td_proc->p_comm, code); 971 972 STOPEVENT(p, S_SCX, code); 973 PTRACESTOP_SC(p, td, S_PT_SCX); 974#ifdef KTRACE 975 if (KTRPOINT(td, KTR_SYSRET)) 976 ktrsysret(code, error, td->td_retval[0]); 977#endif 978 mtx_assert(&sched_lock, MA_NOTOWNED); 979 mtx_assert(&Giant, MA_NOTOWNED); 980} 981 982void 983swi_handler(trapframe_t *frame) 984{ 985 struct thread *td = curthread; 986 uint32_t insn; 987 988 td->td_frame = frame; 989 990 if (td->td_proc->p_flag & P_SA) 991 thread_user_enter(td); 992 /* 993 * Make sure the program counter is correctly aligned so we 994 * don't take an alignment fault trying to read the opcode. 995 */ 996 if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) { 997 trapsignal(td, SIGILL, 0); 998 userret(td, frame, td->td_sticks); 999 return; 1000 } 1001 insn = *(u_int32_t *)(frame->tf_pc - INSN_SIZE); 1002 /* 1003 * Enable interrupts if they were enabled before the exception. 1004 * Since all syscalls *should* come from user mode it will always 1005 * be safe to enable them, but check anyway. 1006 */ 1007 if (td->td_critnest == 0 && !(frame->tf_spsr & I32_bit)) 1008 enable_interrupts(I32_bit); 1009 1010 syscall(td, frame, insn); 1011} 1012 1013