syscall.c revision 173600
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 173600 2007-11-14 06:21:24Z julian $"); 86 87#include <sys/param.h> 88#include <sys/systm.h> 89#include <sys/proc.h> 90#include <sys/kernel.h> 91#include <sys/lock.h> 92#include <sys/mutex.h> 93#include <sys/syscall.h> 94#include <sys/sysent.h> 95#include <sys/signalvar.h> 96#include <sys/ktr.h> 97#ifdef KTRACE 98#include <sys/uio.h> 99#include <sys/ktrace.h> 100#endif 101#include <sys/ptrace.h> 102#include <sys/pioctl.h> 103 104#include <vm/vm.h> 105#include <vm/pmap.h> 106#include <vm/vm_kern.h> 107#include <vm/vm_map.h> 108#include <vm/vm_extern.h> 109 110#include <machine/cpuconf.h> 111#include <machine/vmparam.h> 112#include <machine/frame.h> 113#include <machine/cpu.h> 114#include <machine/intr.h> 115#include <machine/pcb.h> 116#include <machine/proc.h> 117#include <machine/swi.h> 118 119#include <security/audit/audit.h> 120 121#ifdef KDB 122#include <sys/kdb.h> 123#endif 124 125 126void swi_handler(trapframe_t *); 127void undefinedinstruction(trapframe_t *); 128 129#include <machine/disassem.h> 130#include <machine/machdep.h> 131 132extern char fusubailout[]; 133extern char *syscallnames[]; 134 135#ifdef DEBUG 136int last_fault_code; /* For the benefit of pmap_fault_fixup() */ 137#endif 138 139#if defined(CPU_ARM7TDMI) 140/* These CPUs may need data/prefetch abort fixups */ 141#define CPU_ABORT_FIXUP_REQUIRED 142#endif 143 144struct ksig { 145 int signb; 146 u_long code; 147}; 148struct data_abort { 149 int (*func)(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 150 const char *desc; 151}; 152 153static int dab_fatal(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 154static int dab_align(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 155static int dab_buserr(trapframe_t *, u_int, u_int, struct thread *, struct ksig *); 156 157static const struct data_abort data_aborts[] = { 158 {dab_fatal, "Vector Exception"}, 159 {dab_align, "Alignment Fault 1"}, 160 {dab_fatal, "Terminal Exception"}, 161 {dab_align, "Alignment Fault 3"}, 162 {dab_buserr, "External Linefetch Abort (S)"}, 163 {NULL, "Translation Fault (S)"}, 164 {dab_buserr, "External Linefetch Abort (P)"}, 165 {NULL, "Translation Fault (P)"}, 166 {dab_buserr, "External Non-Linefetch Abort (S)"}, 167 {NULL, "Domain Fault (S)"}, 168 {dab_buserr, "External Non-Linefetch Abort (P)"}, 169 {NULL, "Domain Fault (P)"}, 170 {dab_buserr, "External Translation Abort (L1)"}, 171 {NULL, "Permission Fault (S)"}, 172 {dab_buserr, "External Translation Abort (L2)"}, 173 {NULL, "Permission Fault (P)"} 174}; 175 176/* Determine if a fault came from user mode */ 177#define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE) 178 179/* Determine if 'x' is a permission fault */ 180#define IS_PERMISSION_FAULT(x) \ 181 (((1 << ((x) & FAULT_TYPE_MASK)) & \ 182 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0) 183 184static __inline void 185call_trapsignal(struct thread *td, int sig, u_long code) 186{ 187 ksiginfo_t ksi; 188 189 ksiginfo_init_trap(&ksi); 190 ksi.ksi_signo = sig; 191 ksi.ksi_code = (int)code; 192 trapsignal(td, &ksi); 193} 194 195static __inline int 196data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 197{ 198#ifdef CPU_ABORT_FIXUP_REQUIRED 199 int error; 200 201 /* Call the cpu specific data abort fixup routine */ 202 error = cpu_dataabt_fixup(tf); 203 if (__predict_true(error != ABORT_FIXUP_FAILED)) 204 return (error); 205 206 /* 207 * Oops, couldn't fix up the instruction 208 */ 209 printf("data_abort_fixup: fixup for %s mode data abort failed.\n", 210 TRAP_USERMODE(tf) ? "user" : "kernel"); 211 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 212 *((u_int *)tf->tf_pc)); 213 disassemble(tf->tf_pc); 214 215 /* Die now if this happened in kernel mode */ 216 if (!TRAP_USERMODE(tf)) 217 dab_fatal(tf, fsr, far, td, NULL, ksig); 218 219 return (error); 220#else 221 return (ABORT_FIXUP_OK); 222#endif /* CPU_ABORT_FIXUP_REQUIRED */ 223} 224 225void 226data_abort_handler(trapframe_t *tf) 227{ 228 struct vm_map *map; 229 struct pcb *pcb; 230 struct thread *td; 231 u_int user, far, fsr; 232 vm_prot_t ftype; 233 void *onfault; 234 vm_offset_t va; 235 int error = 0; 236 struct ksig ksig; 237 struct proc *p; 238 239 240 /* Grab FAR/FSR before enabling interrupts */ 241 far = cpu_faultaddress(); 242 fsr = cpu_faultstatus(); 243#if 0 244 printf("data abort: %p (from %p %p)\n", (void*)far, (void*)tf->tf_pc, 245 (void*)tf->tf_svc_lr); 246#endif 247 248 /* Update vmmeter statistics */ 249#if 0 250 vmexp.traps++; 251#endif 252 253 td = curthread; 254 p = td->td_proc; 255 256 PCPU_INC(cnt.v_trap); 257 /* Data abort came from user mode? */ 258 user = TRAP_USERMODE(tf); 259 260 if (user) { 261 td->td_pticks = 0; 262 td->td_frame = tf; 263 if (td->td_ucred != td->td_proc->p_ucred) 264 cred_update_thread(td); 265#ifdef KSE 266 if (td->td_pflags & TDP_SA) 267 thread_user_enter(td); 268#endif 269 270 } 271 /* Grab the current pcb */ 272 pcb = td->td_pcb; 273 /* Re-enable interrupts if they were enabled previously */ 274 if (td->td_md.md_spinlock_count == 0) { 275 if (__predict_true(tf->tf_spsr & I32_bit) == 0) 276 enable_interrupts(I32_bit); 277 if (__predict_true(tf->tf_spsr & F32_bit) == 0) 278 enable_interrupts(F32_bit); 279 } 280 281 282 /* Invoke the appropriate handler, if necessary */ 283 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 284 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 285 td, &ksig)) { 286 goto do_trapsignal; 287 } 288 goto out; 289 } 290 291 /* 292 * At this point, we're dealing with one of the following data aborts: 293 * 294 * FAULT_TRANS_S - Translation -- Section 295 * FAULT_TRANS_P - Translation -- Page 296 * FAULT_DOMAIN_S - Domain -- Section 297 * FAULT_DOMAIN_P - Domain -- Page 298 * FAULT_PERM_S - Permission -- Section 299 * FAULT_PERM_P - Permission -- Page 300 * 301 * These are the main virtual memory-related faults signalled by 302 * the MMU. 303 */ 304 305 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 306 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 307 tf->tf_r0 = EFAULT; 308 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 309 return; 310 } 311 312 /* 313 * Make sure the Program Counter is sane. We could fall foul of 314 * someone executing Thumb code, in which case the PC might not 315 * be word-aligned. This would cause a kernel alignment fault 316 * further down if we have to decode the current instruction. 317 * XXX: It would be nice to be able to support Thumb at some point. 318 */ 319 if (__predict_false((tf->tf_pc & 3) != 0)) { 320 if (user) { 321 /* 322 * Give the user an illegal instruction signal. 323 */ 324 /* Deliver a SIGILL to the process */ 325 ksig.signb = SIGILL; 326 ksig.code = 0; 327 goto do_trapsignal; 328 } 329 330 /* 331 * The kernel never executes Thumb code. 332 */ 333 printf("\ndata_abort_fault: Misaligned Kernel-mode " 334 "Program Counter\n"); 335 dab_fatal(tf, fsr, far, td, &ksig); 336 } 337 338 /* See if the cpu state needs to be fixed up */ 339 switch (data_abort_fixup(tf, fsr, far, td, &ksig)) { 340 case ABORT_FIXUP_RETURN: 341 return; 342 case ABORT_FIXUP_FAILED: 343 /* Deliver a SIGILL to the process */ 344 ksig.signb = SIGILL; 345 ksig.code = 0; 346 goto do_trapsignal; 347 default: 348 break; 349 } 350 351 va = trunc_page((vm_offset_t)far); 352 353 /* 354 * It is only a kernel address space fault iff: 355 * 1. user == 0 and 356 * 2. pcb_onfault not set or 357 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 358 */ 359 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 360 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 361 __predict_true((pcb->pcb_onfault == NULL || 362 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 363 map = kernel_map; 364 365 /* Was the fault due to the FPE/IPKDB ? */ 366 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 367 368 /* 369 * Force exit via userret() 370 * This is necessary as the FPE is an extension to 371 * userland that actually runs in a priveledged mode 372 * but uses USR mode permissions for its accesses. 373 */ 374 user = 1; 375 ksig.signb = SIGSEGV; 376 ksig.code = 0; 377 goto do_trapsignal; 378 } 379 } else { 380 map = &td->td_proc->p_vmspace->vm_map; 381 } 382 383 /* 384 * We need to know whether the page should be mapped 385 * as R or R/W. The MMU does not give us the info as 386 * to whether the fault was caused by a read or a write. 387 * 388 * However, we know that a permission fault can only be 389 * the result of a write to a read-only location, so 390 * we can deal with those quickly. 391 * 392 * Otherwise we need to disassemble the instruction 393 * responsible to determine if it was a write. 394 */ 395 if (IS_PERMISSION_FAULT(fsr)) { 396 ftype = VM_PROT_WRITE; 397 } else { 398 u_int insn = ReadWord(tf->tf_pc); 399 400 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */ 401 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */ 402 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT */ 403 { 404 ftype = VM_PROT_WRITE; 405 } 406 else 407 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */ 408 ftype = VM_PROT_READ | VM_PROT_WRITE; 409 else 410 ftype = VM_PROT_READ; 411 } 412 413 /* 414 * See if the fault is as a result of ref/mod emulation, 415 * or domain mismatch. 416 */ 417#ifdef DEBUG 418 last_fault_code = fsr; 419#endif 420 if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype, 421 user)) { 422 goto out; 423 } 424 425 onfault = pcb->pcb_onfault; 426 pcb->pcb_onfault = NULL; 427 if (map != kernel_map) { 428 PROC_LOCK(p); 429 p->p_lock++; 430 PROC_UNLOCK(p); 431 } 432 error = vm_fault(map, va, ftype, (ftype & VM_PROT_WRITE) ? 433 VM_FAULT_DIRTY : VM_FAULT_NORMAL); 434 pcb->pcb_onfault = onfault; 435 436 if (map != kernel_map) { 437 PROC_LOCK(p); 438 p->p_lock--; 439 PROC_UNLOCK(p); 440 } 441 if (__predict_true(error == 0)) 442 goto out; 443 if (user == 0) { 444 if (pcb->pcb_onfault) { 445 tf->tf_r0 = error; 446 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 447 return; 448 } 449 450 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype, 451 error); 452 dab_fatal(tf, fsr, far, td, &ksig); 453 } 454 455 456 if (error == ENOMEM) { 457 printf("VM: pid %d (%s), uid %d killed: " 458 "out of swap\n", td->td_proc->p_pid, td->td_name, 459 (td->td_proc->p_ucred) ? 460 td->td_proc->p_ucred->cr_uid : -1); 461 ksig.signb = SIGKILL; 462 } else { 463 ksig.signb = SIGSEGV; 464 } 465 ksig.code = 0; 466do_trapsignal: 467 call_trapsignal(td, ksig.signb, ksig.code); 468out: 469 /* If returning to user mode, make sure to invoke userret() */ 470 if (user) 471 userret(td, tf); 472} 473 474/* 475 * dab_fatal() handles the following data aborts: 476 * 477 * FAULT_WRTBUF_0 - Vector Exception 478 * FAULT_WRTBUF_1 - Terminal Exception 479 * 480 * We should never see these on a properly functioning system. 481 * 482 * This function is also called by the other handlers if they 483 * detect a fatal problem. 484 * 485 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 486 */ 487static int 488dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 489{ 490 const char *mode; 491 492 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 493 494 disable_interrupts(I32_bit|F32_bit); 495 if (td != NULL) { 496 printf("Fatal %s mode data abort: '%s'\n", mode, 497 data_aborts[fsr & FAULT_TYPE_MASK].desc); 498 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 499 if ((fsr & FAULT_IMPRECISE) == 0) 500 printf("%08x, ", far); 501 else 502 printf("Invalid, "); 503 printf("spsr=%08x\n", tf->tf_spsr); 504 } else { 505 printf("Fatal %s mode prefetch abort at 0x%08x\n", 506 mode, tf->tf_pc); 507 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 508 } 509 510 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 511 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 512 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 513 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 514 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 515 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 516 printf("r12=%08x, ", tf->tf_r12); 517 518 if (TRAP_USERMODE(tf)) 519 printf("usp=%08x, ulr=%08x", 520 tf->tf_usr_sp, tf->tf_usr_lr); 521 else 522 printf("ssp=%08x, slr=%08x", 523 tf->tf_svc_sp, tf->tf_svc_lr); 524 printf(", pc =%08x\n\n", tf->tf_pc); 525 526#ifdef KDB 527 kdb_trap(fsr, 0, tf); 528#endif 529 panic("Fatal abort"); 530 /*NOTREACHED*/ 531} 532 533/* 534 * dab_align() handles the following data aborts: 535 * 536 * FAULT_ALIGN_0 - Alignment fault 537 * FAULT_ALIGN_0 - Alignment fault 538 * 539 * These faults are fatal if they happen in kernel mode. Otherwise, we 540 * deliver a bus error to the process. 541 */ 542static int 543dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 544{ 545 546 /* Alignment faults are always fatal if they occur in kernel mode */ 547 if (!TRAP_USERMODE(tf)) { 548 if (!td || !td->td_pcb->pcb_onfault) 549 dab_fatal(tf, fsr, far, td, ksig); 550 tf->tf_r0 = EFAULT; 551 tf->tf_pc = (int)td->td_pcb->pcb_onfault; 552 return (0); 553 } 554 555 /* pcb_onfault *must* be NULL at this point */ 556 557 /* See if the cpu state needs to be fixed up */ 558 (void) data_abort_fixup(tf, fsr, far, td, ksig); 559 560 /* Deliver a bus error signal to the process */ 561 ksig->code = 0; 562 ksig->signb = SIGBUS; 563 td->td_frame = tf; 564 565 return (1); 566} 567 568/* 569 * dab_buserr() handles the following data aborts: 570 * 571 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 572 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 573 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 574 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 575 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 576 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 577 * 578 * If pcb_onfault is set, flag the fault and return to the handler. 579 * If the fault occurred in user mode, give the process a SIGBUS. 580 * 581 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 582 * can be flagged as imprecise in the FSR. This causes a real headache 583 * since some of the machine state is lost. In this case, tf->tf_pc 584 * may not actually point to the offending instruction. In fact, if 585 * we've taken a double abort fault, it generally points somewhere near 586 * the top of "data_abort_entry" in exception.S. 587 * 588 * In all other cases, these data aborts are considered fatal. 589 */ 590static int 591dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 592{ 593 struct pcb *pcb = td->td_pcb; 594 595#ifdef __XSCALE__ 596 if ((fsr & FAULT_IMPRECISE) != 0 && 597 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 598 /* 599 * Oops, an imprecise, double abort fault. We've lost the 600 * r14_abt/spsr_abt values corresponding to the original 601 * abort, and the spsr saved in the trapframe indicates 602 * ABT mode. 603 */ 604 tf->tf_spsr &= ~PSR_MODE; 605 606 /* 607 * We use a simple heuristic to determine if the double abort 608 * happened as a result of a kernel or user mode access. 609 * If the current trapframe is at the top of the kernel stack, 610 * the fault _must_ have come from user mode. 611 */ 612 if (tf != ((trapframe_t *)pcb->un_32.pcb32_sp) - 1) { 613 /* 614 * Kernel mode. We're either about to die a 615 * spectacular death, or pcb_onfault will come 616 * to our rescue. Either way, the current value 617 * of tf->tf_pc is irrelevant. 618 */ 619 tf->tf_spsr |= PSR_SVC32_MODE; 620 if (pcb->pcb_onfault == NULL) 621 printf("\nKernel mode double abort!\n"); 622 } else { 623 /* 624 * User mode. We've lost the program counter at the 625 * time of the fault (not that it was accurate anyway; 626 * it's not called an imprecise fault for nothing). 627 * About all we can do is copy r14_usr to tf_pc and 628 * hope for the best. The process is about to get a 629 * SIGBUS, so it's probably history anyway. 630 */ 631 tf->tf_spsr |= PSR_USR32_MODE; 632 tf->tf_pc = tf->tf_usr_lr; 633 } 634 } 635 636 /* FAR is invalid for imprecise exceptions */ 637 if ((fsr & FAULT_IMPRECISE) != 0) 638 far = 0; 639#endif /* __XSCALE__ */ 640 641 if (pcb->pcb_onfault) { 642 tf->tf_r0 = EFAULT; 643 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 644 return (0); 645 } 646 647 /* See if the cpu state needs to be fixed up */ 648 (void) data_abort_fixup(tf, fsr, far, td, ksig); 649 650 /* 651 * At this point, if the fault happened in kernel mode, we're toast 652 */ 653 if (!TRAP_USERMODE(tf)) 654 dab_fatal(tf, fsr, far, td, ksig); 655 656 /* Deliver a bus error signal to the process */ 657 ksig->signb = SIGBUS; 658 ksig->code = 0; 659 td->td_frame = tf; 660 661 return (1); 662} 663 664static __inline int 665prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig) 666{ 667#ifdef CPU_ABORT_FIXUP_REQUIRED 668 int error; 669 670 /* Call the cpu specific prefetch abort fixup routine */ 671 error = cpu_prefetchabt_fixup(tf); 672 if (__predict_true(error != ABORT_FIXUP_FAILED)) 673 return (error); 674 675 /* 676 * Oops, couldn't fix up the instruction 677 */ 678 printf( 679 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n", 680 TRAP_USERMODE(tf) ? "user" : "kernel"); 681 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 682 *((u_int *)tf->tf_pc)); 683 disassemble(tf->tf_pc); 684 685 /* Die now if this happened in kernel mode */ 686 if (!TRAP_USERMODE(tf)) 687 dab_fatal(tf, 0, tf->tf_pc, NULL, ksig); 688 689 return (error); 690#else 691 return (ABORT_FIXUP_OK); 692#endif /* CPU_ABORT_FIXUP_REQUIRED */ 693} 694 695/* 696 * void prefetch_abort_handler(trapframe_t *tf) 697 * 698 * Abort handler called when instruction execution occurs at 699 * a non existent or restricted (access permissions) memory page. 700 * If the address is invalid and we were in SVC mode then panic as 701 * the kernel should never prefetch abort. 702 * If the address is invalid and the page is mapped then the user process 703 * does no have read permission so send it a signal. 704 * Otherwise fault the page in and try again. 705 */ 706void 707prefetch_abort_handler(trapframe_t *tf) 708{ 709 struct thread *td; 710 struct proc * p; 711 struct vm_map *map; 712 vm_offset_t fault_pc, va; 713 int error = 0; 714 struct ksig ksig; 715 716 717#if 0 718 /* Update vmmeter statistics */ 719 uvmexp.traps++; 720#endif 721#if 0 722 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, 723 (void*)tf->tf_usr_lr); 724#endif 725 726 td = curthread; 727 p = td->td_proc; 728 PCPU_INC(cnt.v_trap); 729 730 if (TRAP_USERMODE(tf)) { 731 td->td_frame = tf; 732 if (td->td_ucred != td->td_proc->p_ucred) 733 cred_update_thread(td); 734#ifdef KSE 735 if (td->td_proc->p_flag & P_SA) 736 thread_user_enter(td); 737#endif 738 } 739 fault_pc = tf->tf_pc; 740 if (td->td_md.md_spinlock_count == 0) { 741 if (__predict_true(tf->tf_spsr & I32_bit) == 0) 742 enable_interrupts(I32_bit); 743 if (__predict_true(tf->tf_spsr & F32_bit) == 0) 744 enable_interrupts(F32_bit); 745 } 746 747 748 749 /* See if the cpu state needs to be fixed up */ 750 switch (prefetch_abort_fixup(tf, &ksig)) { 751 case ABORT_FIXUP_RETURN: 752 return; 753 case ABORT_FIXUP_FAILED: 754 /* Deliver a SIGILL to the process */ 755 ksig.signb = SIGILL; 756 ksig.code = 0; 757 td->td_frame = tf; 758 goto do_trapsignal; 759 default: 760 break; 761 } 762 763 /* Prefetch aborts cannot happen in kernel mode */ 764 if (__predict_false(!TRAP_USERMODE(tf))) 765 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); 766 td->td_pticks = 0; 767 768 769 /* Ok validate the address, can only execute in USER space */ 770 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 771 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 772 ksig.signb = SIGSEGV; 773 ksig.code = 0; 774 goto do_trapsignal; 775 } 776 777 map = &td->td_proc->p_vmspace->vm_map; 778 va = trunc_page(fault_pc); 779 780 /* 781 * See if the pmap can handle this fault on its own... 782 */ 783#ifdef DEBUG 784 last_fault_code = -1; 785#endif 786 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) 787 goto out; 788 789 if (map != kernel_map) { 790 PROC_LOCK(p); 791 p->p_lock++; 792 PROC_UNLOCK(p); 793 } 794 795 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, 796 VM_FAULT_NORMAL); 797 if (map != kernel_map) { 798 PROC_LOCK(p); 799 p->p_lock--; 800 PROC_UNLOCK(p); 801 } 802 803 if (__predict_true(error == 0)) 804 goto out; 805 806 if (error == ENOMEM) { 807 printf("VM: pid %d (%s), uid %d killed: " 808 "out of swap\n", td->td_proc->p_pid, td->td_name, 809 (td->td_proc->p_ucred) ? 810 td->td_proc->p_ucred->cr_uid : -1); 811 ksig.signb = SIGKILL; 812 } else { 813 ksig.signb = SIGSEGV; 814 } 815 ksig.code = 0; 816 817do_trapsignal: 818 call_trapsignal(td, ksig.signb, ksig.code); 819 820out: 821 userret(td, tf); 822 823} 824 825extern int badaddr_read_1(const uint8_t *, uint8_t *); 826extern int badaddr_read_2(const uint16_t *, uint16_t *); 827extern int badaddr_read_4(const uint32_t *, uint32_t *); 828/* 829 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 830 * If the read succeeds, the value is written to 'rptr' and zero is returned. 831 * Else, return EFAULT. 832 */ 833int 834badaddr_read(void *addr, size_t size, void *rptr) 835{ 836 union { 837 uint8_t v1; 838 uint16_t v2; 839 uint32_t v4; 840 } u; 841 int rv; 842 843 cpu_drain_writebuf(); 844 845 /* Read from the test address. */ 846 switch (size) { 847 case sizeof(uint8_t): 848 rv = badaddr_read_1(addr, &u.v1); 849 if (rv == 0 && rptr) 850 *(uint8_t *) rptr = u.v1; 851 break; 852 853 case sizeof(uint16_t): 854 rv = badaddr_read_2(addr, &u.v2); 855 if (rv == 0 && rptr) 856 *(uint16_t *) rptr = u.v2; 857 break; 858 859 case sizeof(uint32_t): 860 rv = badaddr_read_4(addr, &u.v4); 861 if (rv == 0 && rptr) 862 *(uint32_t *) rptr = u.v4; 863 break; 864 865 default: 866 panic("badaddr: invalid size (%lu)", (u_long) size); 867 } 868 869 /* Return EFAULT if the address was invalid, else zero */ 870 return (rv); 871} 872 873#define MAXARGS 8 874static void 875syscall(struct thread *td, trapframe_t *frame, u_int32_t insn) 876{ 877 struct proc *p = td->td_proc; 878 int code, error; 879 u_int nap, nargs; 880 register_t *ap, *args, copyargs[MAXARGS]; 881 struct sysent *callp; 882 883 PCPU_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[_QUAD_LOWWORD]; 905 nap -= 2; 906 ap += 2; 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; 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_name, code); 931 if (error == 0) { 932 td->td_retval[0] = 0; 933 td->td_retval[1] = 0; 934 STOPEVENT(p, S_SCE, callp->sy_narg); 935 PTRACESTOP_SC(p, td, S_PT_SCE); 936 AUDIT_SYSCALL_ENTER(code, td); 937 error = (*callp->sy_call)(td, args); 938 AUDIT_SYSCALL_EXIT(error, td); 939 KASSERT(td->td_ar == NULL, 940 ("returning from syscall with td_ar set!")); 941 } 942 switch (error) { 943 case 0: 944#ifdef __ARMEB__ 945 if ((insn & 0x000fffff) == SYS___syscall && 946 code != SYS_freebsd6_lseek && code != SYS_lseek) { 947 /* 948 * 64-bit return, 32-bit syscall. Fixup byte order 949 */ 950 frame->tf_r0 = 0; 951 frame->tf_r1 = td->td_retval[0]; 952 } else { 953 frame->tf_r0 = td->td_retval[0]; 954 frame->tf_r1 = td->td_retval[1]; 955 } 956#else 957 frame->tf_r0 = td->td_retval[0]; 958 frame->tf_r1 = td->td_retval[1]; 959#endif 960 961 frame->tf_spsr &= ~PSR_C_bit; /* carry bit */ 962 break; 963 964 case ERESTART: 965 /* 966 * Reconstruct the pc to point at the swi. 967 */ 968 frame->tf_pc -= INSN_SIZE; 969 break; 970 case EJUSTRETURN: 971 /* nothing to do */ 972 break; 973 default: 974bad: 975 frame->tf_r0 = error; 976 frame->tf_spsr |= PSR_C_bit; /* carry bit */ 977 break; 978 } 979 980 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning", 981 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???"); 982 KASSERT(td->td_critnest == 0, 983 ("System call %s returning in a critical section", 984 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???")); 985 KASSERT(td->td_locks == 0, 986 ("System call %s returning with %d locks held", 987 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???", 988 td->td_locks)); 989 990 userret(td, frame); 991 CTR4(KTR_SYSC, "syscall exit thread %p pid %d proc %s code %d", td, 992 td->td_proc->p_pid, td->td_name, code); 993 994 STOPEVENT(p, S_SCX, code); 995 PTRACESTOP_SC(p, td, S_PT_SCX); 996#ifdef KTRACE 997 if (KTRPOINT(td, KTR_SYSRET)) 998 ktrsysret(code, error, td->td_retval[0]); 999#endif 1000} 1001 1002void 1003swi_handler(trapframe_t *frame) 1004{ 1005 struct thread *td = curthread; 1006 uint32_t insn; 1007 1008 td->td_frame = frame; 1009 1010 td->td_pticks = 0; 1011#ifdef KSE 1012 if (td->td_proc->p_flag & P_SA) 1013 thread_user_enter(td); 1014#endif 1015 /* 1016 * Make sure the program counter is correctly aligned so we 1017 * don't take an alignment fault trying to read the opcode. 1018 */ 1019 if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) { 1020 call_trapsignal(td, SIGILL, 0); 1021 userret(td, frame); 1022 return; 1023 } 1024 insn = *(u_int32_t *)(frame->tf_pc - INSN_SIZE); 1025 /* 1026 * Enable interrupts if they were enabled before the exception. 1027 * Since all syscalls *should* come from user mode it will always 1028 * be safe to enable them, but check anyway. 1029 */ 1030 if (td->td_md.md_spinlock_count == 0) { 1031 if (__predict_true(frame->tf_spsr & I32_bit) == 0) 1032 enable_interrupts(I32_bit); 1033 if (__predict_true(frame->tf_spsr & F32_bit) == 0) 1034 enable_interrupts(F32_bit); 1035 } 1036 1037 syscall(td, frame, insn); 1038} 1039 1040