syscall.c revision 190844
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 190844 2009-04-08 12:54:32Z raj $"); 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); 265 266 } 267 /* Grab the current pcb */ 268 pcb = td->td_pcb; 269 /* Re-enable interrupts if they were enabled previously */ 270 if (td->td_md.md_spinlock_count == 0) { 271 if (__predict_true(tf->tf_spsr & I32_bit) == 0) 272 enable_interrupts(I32_bit); 273 if (__predict_true(tf->tf_spsr & F32_bit) == 0) 274 enable_interrupts(F32_bit); 275 } 276 277 278 /* Invoke the appropriate handler, if necessary */ 279 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { 280 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, 281 td, &ksig)) { 282 goto do_trapsignal; 283 } 284 goto out; 285 } 286 287 /* 288 * At this point, we're dealing with one of the following data aborts: 289 * 290 * FAULT_TRANS_S - Translation -- Section 291 * FAULT_TRANS_P - Translation -- Page 292 * FAULT_DOMAIN_S - Domain -- Section 293 * FAULT_DOMAIN_P - Domain -- Page 294 * FAULT_PERM_S - Permission -- Section 295 * FAULT_PERM_P - Permission -- Page 296 * 297 * These are the main virtual memory-related faults signalled by 298 * the MMU. 299 */ 300 301 /* fusubailout is used by [fs]uswintr to avoid page faulting */ 302 if (__predict_false(pcb->pcb_onfault == fusubailout)) { 303 tf->tf_r0 = EFAULT; 304 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 305 return; 306 } 307 308 /* 309 * Make sure the Program Counter is sane. We could fall foul of 310 * someone executing Thumb code, in which case the PC might not 311 * be word-aligned. This would cause a kernel alignment fault 312 * further down if we have to decode the current instruction. 313 * XXX: It would be nice to be able to support Thumb at some point. 314 */ 315 if (__predict_false((tf->tf_pc & 3) != 0)) { 316 if (user) { 317 /* 318 * Give the user an illegal instruction signal. 319 */ 320 /* Deliver a SIGILL to the process */ 321 ksig.signb = SIGILL; 322 ksig.code = 0; 323 goto do_trapsignal; 324 } 325 326 /* 327 * The kernel never executes Thumb code. 328 */ 329 printf("\ndata_abort_fault: Misaligned Kernel-mode " 330 "Program Counter\n"); 331 dab_fatal(tf, fsr, far, td, &ksig); 332 } 333 334 /* See if the cpu state needs to be fixed up */ 335 switch (data_abort_fixup(tf, fsr, far, td, &ksig)) { 336 case ABORT_FIXUP_RETURN: 337 return; 338 case ABORT_FIXUP_FAILED: 339 /* Deliver a SIGILL to the process */ 340 ksig.signb = SIGILL; 341 ksig.code = 0; 342 goto do_trapsignal; 343 default: 344 break; 345 } 346 347 va = trunc_page((vm_offset_t)far); 348 349 /* 350 * It is only a kernel address space fault iff: 351 * 1. user == 0 and 352 * 2. pcb_onfault not set or 353 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. 354 */ 355 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS || 356 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && 357 __predict_true((pcb->pcb_onfault == NULL || 358 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { 359 map = kernel_map; 360 361 /* Was the fault due to the FPE/IPKDB ? */ 362 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { 363 364 /* 365 * Force exit via userret() 366 * This is necessary as the FPE is an extension to 367 * userland that actually runs in a priveledged mode 368 * but uses USR mode permissions for its accesses. 369 */ 370 user = 1; 371 ksig.signb = SIGSEGV; 372 ksig.code = 0; 373 goto do_trapsignal; 374 } 375 } else { 376 map = &td->td_proc->p_vmspace->vm_map; 377 } 378 379 /* 380 * We need to know whether the page should be mapped 381 * as R or R/W. The MMU does not give us the info as 382 * to whether the fault was caused by a read or a write. 383 * 384 * However, we know that a permission fault can only be 385 * the result of a write to a read-only location, so 386 * we can deal with those quickly. 387 * 388 * Otherwise we need to disassemble the instruction 389 * responsible to determine if it was a write. 390 */ 391 if (IS_PERMISSION_FAULT(fsr)) { 392 ftype = VM_PROT_WRITE; 393 } else { 394 u_int insn = ReadWord(tf->tf_pc); 395 396 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */ 397 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */ 398 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT */ 399 { 400 ftype = VM_PROT_WRITE; 401 } 402 else 403 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */ 404 ftype = VM_PROT_READ | VM_PROT_WRITE; 405 else 406 ftype = VM_PROT_READ; 407 } 408 409 /* 410 * See if the fault is as a result of ref/mod emulation, 411 * or domain mismatch. 412 */ 413#ifdef DEBUG 414 last_fault_code = fsr; 415#endif 416 if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype, 417 user)) { 418 goto out; 419 } 420 421 onfault = pcb->pcb_onfault; 422 pcb->pcb_onfault = NULL; 423 if (map != kernel_map) { 424 PROC_LOCK(p); 425 p->p_lock++; 426 PROC_UNLOCK(p); 427 } 428 error = vm_fault(map, va, ftype, (ftype & VM_PROT_WRITE) ? 429 VM_FAULT_DIRTY : VM_FAULT_NORMAL); 430 pcb->pcb_onfault = onfault; 431 432 if (map != kernel_map) { 433 PROC_LOCK(p); 434 p->p_lock--; 435 PROC_UNLOCK(p); 436 } 437 if (__predict_true(error == 0)) 438 goto out; 439 if (user == 0) { 440 if (pcb->pcb_onfault) { 441 tf->tf_r0 = error; 442 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 443 return; 444 } 445 446 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype, 447 error); 448 dab_fatal(tf, fsr, far, td, &ksig); 449 } 450 451 452 if (error == ENOMEM) { 453 printf("VM: pid %d (%s), uid %d killed: " 454 "out of swap\n", td->td_proc->p_pid, td->td_name, 455 (td->td_proc->p_ucred) ? 456 td->td_proc->p_ucred->cr_uid : -1); 457 ksig.signb = SIGKILL; 458 } else { 459 ksig.signb = SIGSEGV; 460 } 461 ksig.code = 0; 462do_trapsignal: 463 call_trapsignal(td, ksig.signb, ksig.code); 464out: 465 /* If returning to user mode, make sure to invoke userret() */ 466 if (user) 467 userret(td, tf); 468} 469 470/* 471 * dab_fatal() handles the following data aborts: 472 * 473 * FAULT_WRTBUF_0 - Vector Exception 474 * FAULT_WRTBUF_1 - Terminal Exception 475 * 476 * We should never see these on a properly functioning system. 477 * 478 * This function is also called by the other handlers if they 479 * detect a fatal problem. 480 * 481 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. 482 */ 483static int 484dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 485{ 486 const char *mode; 487 488 mode = TRAP_USERMODE(tf) ? "user" : "kernel"; 489 490 disable_interrupts(I32_bit|F32_bit); 491 if (td != NULL) { 492 printf("Fatal %s mode data abort: '%s'\n", mode, 493 data_aborts[fsr & FAULT_TYPE_MASK].desc); 494 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); 495 if ((fsr & FAULT_IMPRECISE) == 0) 496 printf("%08x, ", far); 497 else 498 printf("Invalid, "); 499 printf("spsr=%08x\n", tf->tf_spsr); 500 } else { 501 printf("Fatal %s mode prefetch abort at 0x%08x\n", 502 mode, tf->tf_pc); 503 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); 504 } 505 506 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", 507 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); 508 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", 509 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); 510 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", 511 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); 512 printf("r12=%08x, ", tf->tf_r12); 513 514 if (TRAP_USERMODE(tf)) 515 printf("usp=%08x, ulr=%08x", 516 tf->tf_usr_sp, tf->tf_usr_lr); 517 else 518 printf("ssp=%08x, slr=%08x", 519 tf->tf_svc_sp, tf->tf_svc_lr); 520 printf(", pc =%08x\n\n", tf->tf_pc); 521 522#ifdef KDB 523 if (debugger_on_panic || kdb_active) 524 kdb_trap(fsr, 0, tf); 525#endif 526 panic("Fatal abort"); 527 /*NOTREACHED*/ 528} 529 530/* 531 * dab_align() handles the following data aborts: 532 * 533 * FAULT_ALIGN_0 - Alignment fault 534 * FAULT_ALIGN_0 - Alignment fault 535 * 536 * These faults are fatal if they happen in kernel mode. Otherwise, we 537 * deliver a bus error to the process. 538 */ 539static int 540dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 541{ 542 543 /* Alignment faults are always fatal if they occur in kernel mode */ 544 if (!TRAP_USERMODE(tf)) { 545 if (!td || !td->td_pcb->pcb_onfault) 546 dab_fatal(tf, fsr, far, td, ksig); 547 tf->tf_r0 = EFAULT; 548 tf->tf_pc = (int)td->td_pcb->pcb_onfault; 549 return (0); 550 } 551 552 /* pcb_onfault *must* be NULL at this point */ 553 554 /* See if the cpu state needs to be fixed up */ 555 (void) data_abort_fixup(tf, fsr, far, td, ksig); 556 557 /* Deliver a bus error signal to the process */ 558 ksig->code = 0; 559 ksig->signb = SIGBUS; 560 td->td_frame = tf; 561 562 return (1); 563} 564 565/* 566 * dab_buserr() handles the following data aborts: 567 * 568 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section 569 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page 570 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section 571 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page 572 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 573 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 574 * 575 * If pcb_onfault is set, flag the fault and return to the handler. 576 * If the fault occurred in user mode, give the process a SIGBUS. 577 * 578 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 579 * can be flagged as imprecise in the FSR. This causes a real headache 580 * since some of the machine state is lost. In this case, tf->tf_pc 581 * may not actually point to the offending instruction. In fact, if 582 * we've taken a double abort fault, it generally points somewhere near 583 * the top of "data_abort_entry" in exception.S. 584 * 585 * In all other cases, these data aborts are considered fatal. 586 */ 587static int 588dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) 589{ 590 struct pcb *pcb = td->td_pcb; 591 592#ifdef __XSCALE__ 593 if ((fsr & FAULT_IMPRECISE) != 0 && 594 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { 595 /* 596 * Oops, an imprecise, double abort fault. We've lost the 597 * r14_abt/spsr_abt values corresponding to the original 598 * abort, and the spsr saved in the trapframe indicates 599 * ABT mode. 600 */ 601 tf->tf_spsr &= ~PSR_MODE; 602 603 /* 604 * We use a simple heuristic to determine if the double abort 605 * happened as a result of a kernel or user mode access. 606 * If the current trapframe is at the top of the kernel stack, 607 * the fault _must_ have come from user mode. 608 */ 609 if (tf != ((trapframe_t *)pcb->un_32.pcb32_sp) - 1) { 610 /* 611 * Kernel mode. We're either about to die a 612 * spectacular death, or pcb_onfault will come 613 * to our rescue. Either way, the current value 614 * of tf->tf_pc is irrelevant. 615 */ 616 tf->tf_spsr |= PSR_SVC32_MODE; 617 if (pcb->pcb_onfault == NULL) 618 printf("\nKernel mode double abort!\n"); 619 } else { 620 /* 621 * User mode. We've lost the program counter at the 622 * time of the fault (not that it was accurate anyway; 623 * it's not called an imprecise fault for nothing). 624 * About all we can do is copy r14_usr to tf_pc and 625 * hope for the best. The process is about to get a 626 * SIGBUS, so it's probably history anyway. 627 */ 628 tf->tf_spsr |= PSR_USR32_MODE; 629 tf->tf_pc = tf->tf_usr_lr; 630 } 631 } 632 633 /* FAR is invalid for imprecise exceptions */ 634 if ((fsr & FAULT_IMPRECISE) != 0) 635 far = 0; 636#endif /* __XSCALE__ */ 637 638 if (pcb->pcb_onfault) { 639 tf->tf_r0 = EFAULT; 640 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; 641 return (0); 642 } 643 644 /* See if the cpu state needs to be fixed up */ 645 (void) data_abort_fixup(tf, fsr, far, td, ksig); 646 647 /* 648 * At this point, if the fault happened in kernel mode, we're toast 649 */ 650 if (!TRAP_USERMODE(tf)) 651 dab_fatal(tf, fsr, far, td, ksig); 652 653 /* Deliver a bus error signal to the process */ 654 ksig->signb = SIGBUS; 655 ksig->code = 0; 656 td->td_frame = tf; 657 658 return (1); 659} 660 661static __inline int 662prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig) 663{ 664#ifdef CPU_ABORT_FIXUP_REQUIRED 665 int error; 666 667 /* Call the cpu specific prefetch abort fixup routine */ 668 error = cpu_prefetchabt_fixup(tf); 669 if (__predict_true(error != ABORT_FIXUP_FAILED)) 670 return (error); 671 672 /* 673 * Oops, couldn't fix up the instruction 674 */ 675 printf( 676 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n", 677 TRAP_USERMODE(tf) ? "user" : "kernel"); 678 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, 679 *((u_int *)tf->tf_pc)); 680 disassemble(tf->tf_pc); 681 682 /* Die now if this happened in kernel mode */ 683 if (!TRAP_USERMODE(tf)) 684 dab_fatal(tf, 0, tf->tf_pc, NULL, ksig); 685 686 return (error); 687#else 688 return (ABORT_FIXUP_OK); 689#endif /* CPU_ABORT_FIXUP_REQUIRED */ 690} 691 692/* 693 * void prefetch_abort_handler(trapframe_t *tf) 694 * 695 * Abort handler called when instruction execution occurs at 696 * a non existent or restricted (access permissions) memory page. 697 * If the address is invalid and we were in SVC mode then panic as 698 * the kernel should never prefetch abort. 699 * If the address is invalid and the page is mapped then the user process 700 * does no have read permission so send it a signal. 701 * Otherwise fault the page in and try again. 702 */ 703void 704prefetch_abort_handler(trapframe_t *tf) 705{ 706 struct thread *td; 707 struct proc * p; 708 struct vm_map *map; 709 vm_offset_t fault_pc, va; 710 int error = 0; 711 struct ksig ksig; 712 713 714#if 0 715 /* Update vmmeter statistics */ 716 uvmexp.traps++; 717#endif 718#if 0 719 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, 720 (void*)tf->tf_usr_lr); 721#endif 722 723 td = curthread; 724 p = td->td_proc; 725 PCPU_INC(cnt.v_trap); 726 727 if (TRAP_USERMODE(tf)) { 728 td->td_frame = tf; 729 if (td->td_ucred != td->td_proc->p_ucred) 730 cred_update_thread(td); 731 } 732 fault_pc = tf->tf_pc; 733 if (td->td_md.md_spinlock_count == 0) { 734 if (__predict_true(tf->tf_spsr & I32_bit) == 0) 735 enable_interrupts(I32_bit); 736 if (__predict_true(tf->tf_spsr & F32_bit) == 0) 737 enable_interrupts(F32_bit); 738 } 739 740 741 742 /* See if the cpu state needs to be fixed up */ 743 switch (prefetch_abort_fixup(tf, &ksig)) { 744 case ABORT_FIXUP_RETURN: 745 return; 746 case ABORT_FIXUP_FAILED: 747 /* Deliver a SIGILL to the process */ 748 ksig.signb = SIGILL; 749 ksig.code = 0; 750 td->td_frame = tf; 751 goto do_trapsignal; 752 default: 753 break; 754 } 755 756 /* Prefetch aborts cannot happen in kernel mode */ 757 if (__predict_false(!TRAP_USERMODE(tf))) 758 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); 759 td->td_pticks = 0; 760 761 762 /* Ok validate the address, can only execute in USER space */ 763 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || 764 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { 765 ksig.signb = SIGSEGV; 766 ksig.code = 0; 767 goto do_trapsignal; 768 } 769 770 map = &td->td_proc->p_vmspace->vm_map; 771 va = trunc_page(fault_pc); 772 773 /* 774 * See if the pmap can handle this fault on its own... 775 */ 776#ifdef DEBUG 777 last_fault_code = -1; 778#endif 779 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) 780 goto out; 781 782 if (map != kernel_map) { 783 PROC_LOCK(p); 784 p->p_lock++; 785 PROC_UNLOCK(p); 786 } 787 788 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, 789 VM_FAULT_NORMAL); 790 if (map != kernel_map) { 791 PROC_LOCK(p); 792 p->p_lock--; 793 PROC_UNLOCK(p); 794 } 795 796 if (__predict_true(error == 0)) 797 goto out; 798 799 if (error == ENOMEM) { 800 printf("VM: pid %d (%s), uid %d killed: " 801 "out of swap\n", td->td_proc->p_pid, td->td_name, 802 (td->td_proc->p_ucred) ? 803 td->td_proc->p_ucred->cr_uid : -1); 804 ksig.signb = SIGKILL; 805 } else { 806 ksig.signb = SIGSEGV; 807 } 808 ksig.code = 0; 809 810do_trapsignal: 811 call_trapsignal(td, ksig.signb, ksig.code); 812 813out: 814 userret(td, tf); 815 816} 817 818extern int badaddr_read_1(const uint8_t *, uint8_t *); 819extern int badaddr_read_2(const uint16_t *, uint16_t *); 820extern int badaddr_read_4(const uint32_t *, uint32_t *); 821/* 822 * Tentatively read an 8, 16, or 32-bit value from 'addr'. 823 * If the read succeeds, the value is written to 'rptr' and zero is returned. 824 * Else, return EFAULT. 825 */ 826int 827badaddr_read(void *addr, size_t size, void *rptr) 828{ 829 union { 830 uint8_t v1; 831 uint16_t v2; 832 uint32_t v4; 833 } u; 834 int rv; 835 836 cpu_drain_writebuf(); 837 838 /* Read from the test address. */ 839 switch (size) { 840 case sizeof(uint8_t): 841 rv = badaddr_read_1(addr, &u.v1); 842 if (rv == 0 && rptr) 843 *(uint8_t *) rptr = u.v1; 844 break; 845 846 case sizeof(uint16_t): 847 rv = badaddr_read_2(addr, &u.v2); 848 if (rv == 0 && rptr) 849 *(uint16_t *) rptr = u.v2; 850 break; 851 852 case sizeof(uint32_t): 853 rv = badaddr_read_4(addr, &u.v4); 854 if (rv == 0 && rptr) 855 *(uint32_t *) rptr = u.v4; 856 break; 857 858 default: 859 panic("badaddr: invalid size (%lu)", (u_long) size); 860 } 861 862 /* Return EFAULT if the address was invalid, else zero */ 863 return (rv); 864} 865 866#define MAXARGS 8 867static void 868syscall(struct thread *td, trapframe_t *frame, u_int32_t insn) 869{ 870 struct proc *p = td->td_proc; 871 int code, error; 872 u_int nap, nargs; 873 register_t *ap, *args, copyargs[MAXARGS]; 874 struct sysent *callp; 875 876 PCPU_INC(cnt.v_syscall); 877 td->td_pticks = 0; 878 if (td->td_ucred != td->td_proc->p_ucred) 879 cred_update_thread(td); 880 switch (insn & SWI_OS_MASK) { 881 case 0: /* XXX: we need our own one. */ 882 nap = 4; 883 break; 884 default: 885 call_trapsignal(td, SIGILL, 0); 886 userret(td, frame); 887 return; 888 } 889 code = insn & 0x000fffff; 890 td->td_pticks = 0; 891 ap = &frame->tf_r0; 892 if (code == SYS_syscall) { 893 code = *ap++; 894 895 nap--; 896 } else if (code == SYS___syscall) { 897 code = ap[_QUAD_LOWWORD]; 898 nap -= 2; 899 ap += 2; 900 } 901 if (p->p_sysent->sv_mask) 902 code &= p->p_sysent->sv_mask; 903 if (code >= p->p_sysent->sv_size) 904 callp = &p->p_sysent->sv_table[0]; 905 else 906 callp = &p->p_sysent->sv_table[code]; 907 nargs = callp->sy_narg; 908 memcpy(copyargs, ap, nap * sizeof(register_t)); 909 if (nargs > nap) { 910 error = copyin((void *)frame->tf_usr_sp, copyargs + nap, 911 (nargs - nap) * sizeof(register_t)); 912 if (error) 913 goto bad; 914 } 915 args = copyargs; 916 error = 0; 917#ifdef KTRACE 918 if (KTRPOINT(td, KTR_SYSCALL)) 919 ktrsyscall(code, nargs, args); 920#endif 921 922 CTR4(KTR_SYSC, "syscall enter thread %p pid %d proc %s code %d", td, 923 td->td_proc->p_pid, td->td_name, code); 924 if (error == 0) { 925 td->td_retval[0] = 0; 926 td->td_retval[1] = 0; 927 STOPEVENT(p, S_SCE, callp->sy_narg); 928 PTRACESTOP_SC(p, td, S_PT_SCE); 929 AUDIT_SYSCALL_ENTER(code, td); 930 error = (*callp->sy_call)(td, args); 931 AUDIT_SYSCALL_EXIT(error, td); 932 KASSERT(td->td_ar == NULL, 933 ("returning from syscall with td_ar set!")); 934 } 935 switch (error) { 936 case 0: 937#ifdef __ARMEB__ 938 if ((insn & 0x000fffff) == SYS___syscall && 939 code != SYS_freebsd6_lseek && code != SYS_lseek) { 940 /* 941 * 64-bit return, 32-bit syscall. Fixup byte order 942 */ 943 frame->tf_r0 = 0; 944 frame->tf_r1 = td->td_retval[0]; 945 } else { 946 frame->tf_r0 = td->td_retval[0]; 947 frame->tf_r1 = td->td_retval[1]; 948 } 949#else 950 frame->tf_r0 = td->td_retval[0]; 951 frame->tf_r1 = td->td_retval[1]; 952#endif 953 954 frame->tf_spsr &= ~PSR_C_bit; /* carry bit */ 955 break; 956 957 case ERESTART: 958 /* 959 * Reconstruct the pc to point at the swi. 960 */ 961 frame->tf_pc -= INSN_SIZE; 962 break; 963 case EJUSTRETURN: 964 /* nothing to do */ 965 break; 966 default: 967bad: 968 frame->tf_r0 = error; 969 frame->tf_spsr |= PSR_C_bit; /* carry bit */ 970 break; 971 } 972 973 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning", 974 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???"); 975 KASSERT(td->td_critnest == 0, 976 ("System call %s returning in a critical section", 977 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???")); 978 KASSERT(td->td_locks == 0, 979 ("System call %s returning with %d locks held", 980 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???", 981 td->td_locks)); 982 983 userret(td, frame); 984 CTR4(KTR_SYSC, "syscall exit thread %p pid %d proc %s code %d", td, 985 td->td_proc->p_pid, td->td_name, code); 986 987 STOPEVENT(p, S_SCX, code); 988 PTRACESTOP_SC(p, td, S_PT_SCX); 989#ifdef KTRACE 990 if (KTRPOINT(td, KTR_SYSRET)) 991 ktrsysret(code, error, td->td_retval[0]); 992#endif 993} 994 995void 996swi_handler(trapframe_t *frame) 997{ 998 struct thread *td = curthread; 999 uint32_t insn; 1000 1001 td->td_frame = frame; 1002 1003 td->td_pticks = 0; 1004 /* 1005 * Make sure the program counter is correctly aligned so we 1006 * don't take an alignment fault trying to read the opcode. 1007 */ 1008 if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) { 1009 call_trapsignal(td, SIGILL, 0); 1010 userret(td, frame); 1011 return; 1012 } 1013 insn = *(u_int32_t *)(frame->tf_pc - INSN_SIZE); 1014 /* 1015 * Enable interrupts if they were enabled before the exception. 1016 * Since all syscalls *should* come from user mode it will always 1017 * be safe to enable them, but check anyway. 1018 */ 1019 if (td->td_md.md_spinlock_count == 0) { 1020 if (__predict_true(frame->tf_spsr & I32_bit) == 0) 1021 enable_interrupts(I32_bit); 1022 if (__predict_true(frame->tf_spsr & F32_bit) == 0) 1023 enable_interrupts(F32_bit); 1024 } 1025 1026 syscall(td, frame, insn); 1027} 1028 1029