1 /*- 2 * Copyright (C) 1994, David Greenman 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the University of Utah, and William Jolitz. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * from: @(#)trap.c 7.4 (Berkeley) 5/13/91 38 * $Id: trap.c,v 1.71 1996/01/19 03:57:42 dyson Exp $ 39 */ 40 41 /* 42 * 386 Trap and System call handling 43 */ 44 45 #include "opt_ktrace.h" 46 #include "opt_ddb.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/proc.h> 51 #include <sys/acct.h> 52 #include <sys/kernel.h> 53 #include <sys/syscall.h> 54 #include <sys/sysent.h> 55 #include <sys/queue.h> 56 #include <sys/vmmeter.h> 57 #ifdef KTRACE 58 #include <sys/ktrace.h> 59 #endif 60 61 #include <vm/vm.h> 62 #include <vm/vm_param.h> 63 #include <vm/vm_prot.h> 64 #include <vm/lock.h> 65 #include <vm/pmap.h> 66 #include <vm/vm_kern.h> 67 #include <vm/vm_map.h> 68 #include <vm/vm_page.h> 69 #include <vm/vm_extern.h> 70 71 #include <sys/user.h> 72 73 #include <machine/cpu.h> 74 #include <machine/md_var.h> 75 #include <machine/psl.h> 76 #include <machine/reg.h> 77 #include <machine/trap.h> 78 #include <machine/../isa/isa_device.h> 79 80 #ifdef POWERFAIL_NMI 81 # include <syslog.h> 82 # include <machine/clock.h> 83 #endif 84 85 #include "isa.h" 86 #include "npx.h" 87 88 int (*pmath_emulate) __P((struct trapframe *)); 89 90 extern void trap __P((struct trapframe frame)); 91 extern int trapwrite __P((unsigned addr)); 92 extern void syscall __P((struct trapframe frame)); 93 extern void linux_syscall __P((struct trapframe frame)); 94 95 static int trap_pfault __P((struct trapframe *, int)); 96 static void trap_fatal __P((struct trapframe *)); 97 void dblfault_handler __P((void)); 98 99 extern inthand_t IDTVEC(syscall); 100 101 #define MAX_TRAP_MSG 27 102 static char *trap_msg[] = { 103 "", /* 0 unused */ 104 "privileged instruction fault", /* 1 T_PRIVINFLT */ 105 "", /* 2 unused */ 106 "breakpoint instruction fault", /* 3 T_BPTFLT */ 107 "", /* 4 unused */ 108 "", /* 5 unused */ 109 "arithmetic trap", /* 6 T_ARITHTRAP */ 110 "system forced exception", /* 7 T_ASTFLT */ 111 "", /* 8 unused */ 112 "general protection fault", /* 9 T_PROTFLT */ 113 "trace trap", /* 10 T_TRCTRAP */ 114 "", /* 11 unused */ 115 "page fault", /* 12 T_PAGEFLT */ 116 "", /* 13 unused */ 117 "alignment fault", /* 14 T_ALIGNFLT */ 118 "", /* 15 unused */ 119 "", /* 16 unused */ 120 "", /* 17 unused */ 121 "integer divide fault", /* 18 T_DIVIDE */ 122 "non-maskable interrupt trap", /* 19 T_NMI */ 123 "overflow trap", /* 20 T_OFLOW */ 124 "FPU bounds check fault", /* 21 T_BOUND */ 125 "FPU device not available", /* 22 T_DNA */ 126 "double fault", /* 23 T_DOUBLEFLT */ 127 "FPU operand fetch fault", /* 24 T_FPOPFLT */ 128 "invalid TSS fault", /* 25 T_TSSFLT */ 129 "segment not present fault", /* 26 T_SEGNPFLT */ 130 "stack fault", /* 27 T_STKFLT */ 131 }; 132 133 static void userret __P((struct proc *p, struct trapframe *frame, 134 u_quad_t oticks)); 135 136 static inline void 137 userret(p, frame, oticks) 138 struct proc *p; 139 struct trapframe *frame; 140 u_quad_t oticks; 141 { 142 int sig, s; 143 144 while ((sig = CURSIG(p)) != 0) 145 postsig(sig); 146 p->p_priority = p->p_usrpri; 147 if (want_resched) { 148 /* 149 * Since we are curproc, clock will normally just change 150 * our priority without moving us from one queue to another 151 * (since the running process is not on a queue.) 152 * If that happened after we setrunqueue ourselves but before we 153 * mi_switch()'ed, we might not be on the queue indicated by 154 * our priority. 155 */ 156 s = splclock(); 157 setrunqueue(p); 158 p->p_stats->p_ru.ru_nivcsw++; 159 mi_switch(); 160 splx(s); 161 while ((sig = CURSIG(p)) != 0) 162 postsig(sig); 163 } 164 /* 165 * Charge system time if profiling. 166 */ 167 if (p->p_flag & P_PROFIL) { 168 u_quad_t ticks = p->p_sticks - oticks; 169 170 if (ticks) { 171 #ifdef PROFTIMER 172 extern int profscale; 173 addupc(frame->tf_eip, &p->p_stats->p_prof, 174 ticks * profscale); 175 #else 176 addupc(frame->tf_eip, &p->p_stats->p_prof, ticks); 177 #endif 178 } 179 } 180 curpriority = p->p_priority; 181 } 182 183 /* 184 * Exception, fault, and trap interface to the FreeBSD kernel. 185 * This common code is called from assembly language IDT gate entry 186 * routines that prepare a suitable stack frame, and restore this 187 * frame after the exception has been processed. 188 */ 189 190 void 191 trap(frame) 192 struct trapframe frame; 193 { 194 struct proc *p = curproc; 195 u_quad_t sticks = 0; 196 int i = 0, ucode = 0, type, code; 197 #ifdef DEBUG 198 u_long eva; 199 #endif 200 201 type = frame.tf_trapno; 202 code = frame.tf_err; 203 204 if (ISPL(frame.tf_cs) == SEL_UPL) { 205 /* user trap */ 206 207 sticks = p->p_sticks; 208 p->p_md.md_regs = (int *)&frame; 209 210 switch (type) { 211 case T_PRIVINFLT: /* privileged instruction fault */ 212 ucode = type; 213 i = SIGILL; 214 break; 215 216 case T_BPTFLT: /* bpt instruction fault */ 217 case T_TRCTRAP: /* trace trap */ 218 frame.tf_eflags &= ~PSL_T; 219 i = SIGTRAP; 220 break; 221 222 case T_ARITHTRAP: /* arithmetic trap */ 223 ucode = code; 224 i = SIGFPE; 225 break; 226 227 case T_ASTFLT: /* Allow process switch */ 228 astoff(); 229 cnt.v_soft++; 230 if (p->p_flag & P_OWEUPC) { 231 addupc(frame.tf_eip, &p->p_stats->p_prof, 1); 232 p->p_flag &= ~P_OWEUPC; 233 } 234 goto out; 235 236 case T_PROTFLT: /* general protection fault */ 237 case T_SEGNPFLT: /* segment not present fault */ 238 case T_STKFLT: /* stack fault */ 239 case T_TSSFLT: /* invalid TSS fault */ 240 case T_DOUBLEFLT: /* double fault */ 241 default: 242 ucode = code + BUS_SEGM_FAULT ; 243 i = SIGBUS; 244 break; 245 246 case T_PAGEFLT: /* page fault */ 247 i = trap_pfault(&frame, TRUE); 248 if (i == -1) 249 return; 250 if (i == 0) 251 goto out; 252 253 ucode = T_PAGEFLT; 254 break; 255 256 case T_DIVIDE: /* integer divide fault */ 257 ucode = FPE_INTDIV_TRAP; 258 i = SIGFPE; 259 break; 260 261 #if NISA > 0 262 case T_NMI: 263 #ifdef POWERFAIL_NMI 264 goto handle_powerfail; 265 #else /* !POWERFAIL_NMI */ 266 #ifdef DDB 267 /* NMI can be hooked up to a pushbutton for debugging */ 268 printf ("NMI ... going to debugger\n"); 269 if (kdb_trap (type, 0, &frame)) 270 return; 271 #endif /* DDB */ 272 /* machine/parity/power fail/"kitchen sink" faults */ 273 if (isa_nmi(code) == 0) return; 274 panic("NMI indicates hardware failure"); 275 #endif /* POWERFAIL_NMI */ 276 #endif /* NISA > 0 */ 277 278 case T_OFLOW: /* integer overflow fault */ 279 ucode = FPE_INTOVF_TRAP; 280 i = SIGFPE; 281 break; 282 283 case T_BOUND: /* bounds check fault */ 284 ucode = FPE_SUBRNG_TRAP; 285 i = SIGFPE; 286 break; 287 288 case T_DNA: 289 #if NNPX > 0 290 /* if a transparent fault (due to context switch "late") */ 291 if (npxdna()) 292 return; 293 #endif /* NNPX > 0 */ 294 295 if (!pmath_emulate) { 296 i = SIGFPE; 297 ucode = FPE_FPU_NP_TRAP; 298 break; 299 } 300 i = (*pmath_emulate)(&frame); 301 if (i == 0) { 302 if (!(frame.tf_eflags & PSL_T)) 303 return; 304 frame.tf_eflags &= ~PSL_T; 305 i = SIGTRAP; 306 } 307 /* else ucode = emulator_only_knows() XXX */ 308 break; 309 310 case T_FPOPFLT: /* FPU operand fetch fault */ 311 ucode = T_FPOPFLT; 312 i = SIGILL; 313 break; 314 } 315 } else { 316 /* kernel trap */ 317 318 switch (type) { 319 case T_PAGEFLT: /* page fault */ 320 (void) trap_pfault(&frame, FALSE); 321 return; 322 323 case T_PROTFLT: /* general protection fault */ 324 case T_SEGNPFLT: /* segment not present fault */ 325 /* 326 * Invalid segment selectors and out of bounds 327 * %eip's and %esp's can be set up in user mode. 328 * This causes a fault in kernel mode when the 329 * kernel tries to return to user mode. We want 330 * to get this fault so that we can fix the 331 * problem here and not have to check all the 332 * selectors and pointers when the user changes 333 * them. 334 */ 335 #define MAYBE_DORETI_FAULT(where, whereto) \ 336 do { \ 337 if (frame.tf_eip == (int)where) { \ 338 frame.tf_eip = (int)whereto; \ 339 return; \ 340 } \ 341 } while (0) 342 343 if (intr_nesting_level == 0) { 344 MAYBE_DORETI_FAULT(doreti_iret, 345 doreti_iret_fault); 346 MAYBE_DORETI_FAULT(doreti_popl_ds, 347 doreti_popl_ds_fault); 348 MAYBE_DORETI_FAULT(doreti_popl_es, 349 doreti_popl_es_fault); 350 } 351 if (curpcb && curpcb->pcb_onfault) { 352 frame.tf_eip = (int)curpcb->pcb_onfault; 353 return; 354 } 355 break; 356 357 case T_TSSFLT: 358 /* 359 * PSL_NT can be set in user mode and isn't cleared 360 * automatically when the kernel is entered. This 361 * causes a TSS fault when the kernel attempts to 362 * `iret' because the TSS link is uninitialized. We 363 * want to get this fault so that we can fix the 364 * problem here and not every time the kernel is 365 * entered. 366 */ 367 if (frame.tf_eflags & PSL_NT) { 368 frame.tf_eflags &= ~PSL_NT; 369 return; 370 } 371 break; 372 373 case T_TRCTRAP: /* trace trap */ 374 if (frame.tf_eip == (int)IDTVEC(syscall)) { 375 /* 376 * We've just entered system mode via the 377 * syscall lcall. Continue single stepping 378 * silently until the syscall handler has 379 * saved the flags. 380 */ 381 return; 382 } 383 if (frame.tf_eip == (int)IDTVEC(syscall) + 1) { 384 /* 385 * The syscall handler has now saved the 386 * flags. Stop single stepping it. 387 */ 388 frame.tf_eflags &= ~PSL_T; 389 return; 390 } 391 /* 392 * Fall through. 393 */ 394 case T_BPTFLT: 395 /* 396 * If DDB is enabled, let it handle the debugger trap. 397 * Otherwise, debugger traps "can't happen". 398 */ 399 #ifdef DDB 400 if (kdb_trap (type, 0, &frame)) 401 return; 402 #endif 403 break; 404 405 #if NISA > 0 406 case T_NMI: 407 #ifdef POWERFAIL_NMI 408 #ifndef TIMER_FREQ 409 # define TIMER_FREQ 1193182 410 #endif 411 handle_powerfail: 412 { 413 static unsigned lastalert = 0; 414 415 if(time.tv_sec - lastalert > 10) 416 { 417 log(LOG_WARNING, "NMI: power fail\n"); 418 sysbeep(TIMER_FREQ/880, hz); 419 lastalert = time.tv_sec; 420 } 421 return; 422 } 423 #else /* !POWERFAIL_NMI */ 424 #ifdef DDB 425 /* NMI can be hooked up to a pushbutton for debugging */ 426 printf ("NMI ... going to debugger\n"); 427 if (kdb_trap (type, 0, &frame)) 428 return; 429 #endif /* DDB */ 430 /* machine/parity/power fail/"kitchen sink" faults */ 431 if (isa_nmi(code) == 0) return; 432 /* FALL THROUGH */ 433 #endif /* POWERFAIL_NMI */ 434 #endif /* NISA > 0 */ 435 } 436 437 trap_fatal(&frame); 438 return; 439 } 440 441 trapsignal(p, i, ucode); 442 443 #ifdef DEBUG 444 eva = rcr2(); 445 if (type <= MAX_TRAP_MSG) { 446 uprintf("fatal process exception: %s", 447 trap_msg[type]); 448 if ((type == T_PAGEFLT) || (type == T_PROTFLT)) 449 uprintf(", fault VA = 0x%x", eva); 450 uprintf("\n"); 451 } 452 #endif 453 454 out: 455 userret(p, &frame, sticks); 456 } 457 458 #ifdef notyet 459 /* 460 * This version doesn't allow a page fault to user space while 461 * in the kernel. The rest of the kernel needs to be made "safe" 462 * before this can be used. I think the only things remaining 463 * to be made safe are the iBCS2 code and the process tracing/ 464 * debugging code. 465 */ 466 static int 467 trap_pfault(frame, usermode) 468 struct trapframe *frame; 469 int usermode; 470 { 471 vm_offset_t va; 472 struct vmspace *vm = NULL; 473 vm_map_t map = 0; 474 int rv = 0; 475 vm_prot_t ftype; 476 int eva; 477 struct proc *p = curproc; 478 479 if (frame->tf_err & PGEX_W) 480 ftype = VM_PROT_READ | VM_PROT_WRITE; 481 else 482 ftype = VM_PROT_READ; 483 484 eva = rcr2(); 485 va = trunc_page((vm_offset_t)eva); 486 487 if (va < VM_MIN_KERNEL_ADDRESS) { 488 vm_offset_t v; 489 vm_page_t mpte; 490 491 if (p == NULL || 492 (!usermode && va < VM_MAXUSER_ADDRESS && 493 (curpcb == NULL || curpcb->pcb_onfault == NULL))) { 494 trap_fatal(frame); 495 return (-1); 496 } 497 498 /* 499 * This is a fault on non-kernel virtual memory. 500 * vm is initialized above to NULL. If curproc is NULL 501 * or curproc->p_vmspace is NULL the fault is fatal. 502 */ 503 vm = p->p_vmspace; 504 if (vm == NULL) 505 goto nogo; 506 507 map = &vm->vm_map; 508 509 /* 510 * Keep swapout from messing with us during this 511 * critical time. 512 */ 513 ++p->p_lock; 514 515 /* 516 * Grow the stack if necessary 517 */ 518 if ((caddr_t)va > vm->vm_maxsaddr 519 && (caddr_t)va < (caddr_t)USRSTACK) { 520 if (!grow(p, va)) { 521 rv = KERN_FAILURE; 522 --p->p_lock; 523 goto nogo; 524 } 525 } 526 527 /* 528 * Check if page table is mapped, if not, 529 * fault it first 530 */ 531 v = (vm_offset_t) vtopte(va); 532 533 /* Fault the pte only if needed: */ 534 if (*((int *)vtopte(v)) == 0) 535 (void) vm_fault(map, trunc_page(v), VM_PROT_WRITE, FALSE); 536 537 mpte = pmap_use_pt( vm_map_pmap(map), va); 538 539 /* Fault in the user page: */ 540 rv = vm_fault(map, va, ftype, FALSE); 541 542 pmap_unuse_pt( vm_map_pmap(map), va, mpte); 543 544 --p->p_lock; 545 } else { 546 /* 547 * Don't allow user-mode faults in kernel address space. 548 */ 549 if (usermode) 550 goto nogo; 551 552 /* 553 * Since we know that kernel virtual address addresses 554 * always have pte pages mapped, we just have to fault 555 * the page. 556 */ 557 rv = vm_fault(kernel_map, va, ftype, FALSE); 558 } 559 560 if (rv == KERN_SUCCESS) 561 return (0); 562 nogo: 563 if (!usermode) { 564 if (curpcb && curpcb->pcb_onfault) { 565 frame->tf_eip = (int)curpcb->pcb_onfault; 566 return (0); 567 } 568 trap_fatal(frame); 569 return (-1); 570 } 571 572 /* kludge to pass faulting virtual address to sendsig */ 573 frame->tf_err = eva; 574 575 return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV); 576 } 577 #endif 578 579 int 580 trap_pfault(frame, usermode) 581 struct trapframe *frame; 582 int usermode; 583 { 584 vm_offset_t va; 585 struct vmspace *vm = NULL; 586 vm_map_t map = 0; 587 int rv = 0; 588 vm_prot_t ftype; 589 int eva; 590 struct proc *p = curproc; 591 592 eva = rcr2(); 593 va = trunc_page((vm_offset_t)eva); 594 595 if (va >= KERNBASE) { 596 /* 597 * Don't allow user-mode faults in kernel address space. 598 */ 599 if (usermode) 600 goto nogo; 601 602 map = kernel_map; 603 } else { 604 /* 605 * This is a fault on non-kernel virtual memory. 606 * vm is initialized above to NULL. If curproc is NULL 607 * or curproc->p_vmspace is NULL the fault is fatal. 608 */ 609 if (p != NULL) 610 vm = p->p_vmspace; 611 612 if (vm == NULL) 613 goto nogo; 614 615 map = &vm->vm_map; 616 } 617 618 if (frame->tf_err & PGEX_W) 619 ftype = VM_PROT_READ | VM_PROT_WRITE; 620 else 621 ftype = VM_PROT_READ; 622 623 if (map != kernel_map) { 624 vm_offset_t v; 625 vm_page_t mpte; 626 627 /* 628 * Keep swapout from messing with us during this 629 * critical time. 630 */ 631 ++p->p_lock; 632 633 /* 634 * Grow the stack if necessary 635 */ 636 if ((caddr_t)va > vm->vm_maxsaddr 637 && (caddr_t)va < (caddr_t)USRSTACK) { 638 if (!grow(p, va)) { 639 rv = KERN_FAILURE; 640 --p->p_lock; 641 goto nogo; 642 } 643 } 644 645 /* 646 * Check if page table is mapped, if not, 647 * fault it first 648 */ 649 v = (vm_offset_t) vtopte(va); 650 651 /* Fault the pte only if needed: */ 652 if (*((int *)vtopte(v)) == 0) 653 (void) vm_fault(map, 654 trunc_page(v), VM_PROT_WRITE, FALSE); 655 656 mpte = pmap_use_pt( vm_map_pmap(map), va); 657 658 /* Fault in the user page: */ 659 rv = vm_fault(map, va, ftype, FALSE); 660 661 pmap_unuse_pt( vm_map_pmap(map), va, mpte); 662 663 --p->p_lock; 664 } else { 665 /* 666 * Since we know that kernel virtual address addresses 667 * always have pte pages mapped, we just have to fault 668 * the page. 669 */ 670 rv = vm_fault(map, va, ftype, FALSE); 671 } 672 673 if (rv == KERN_SUCCESS) 674 return (0); 675 nogo: 676 if (!usermode) { 677 if (curpcb && curpcb->pcb_onfault) { 678 frame->tf_eip = (int)curpcb->pcb_onfault; 679 return (0); 680 } 681 trap_fatal(frame); 682 return (-1); 683 } 684 685 /* kludge to pass faulting virtual address to sendsig */ 686 frame->tf_err = eva; 687 688 return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV); 689 } 690 691 static void 692 trap_fatal(frame) 693 struct trapframe *frame; 694 { 695 int code, type, eva; 696 struct soft_segment_descriptor softseg; 697 698 code = frame->tf_err; 699 type = frame->tf_trapno; 700 eva = rcr2(); 701 sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)].sd, &softseg); 702 703 if (type <= MAX_TRAP_MSG) 704 printf("\n\nFatal trap %d: %s while in %s mode\n", 705 type, trap_msg[type], 706 ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel"); 707 if (type == T_PAGEFLT) { 708 printf("fault virtual address = 0x%x\n", eva); 709 printf("fault code = %s %s, %s\n", 710 code & PGEX_U ? "user" : "supervisor", 711 code & PGEX_W ? "write" : "read", 712 code & PGEX_P ? "protection violation" : "page not present"); 713 } 714 printf("instruction pointer = 0x%x:0x%x\n", frame->tf_cs & 0xffff, frame->tf_eip); 715 printf("code segment = base 0x%x, limit 0x%x, type 0x%x\n", 716 softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type); 717 printf(" = DPL %d, pres %d, def32 %d, gran %d\n", 718 softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_def32, softseg.ssd_gran); 719 printf("processor eflags = "); 720 if (frame->tf_eflags & PSL_T) 721 printf("trace/trap, "); 722 if (frame->tf_eflags & PSL_I) 723 printf("interrupt enabled, "); 724 if (frame->tf_eflags & PSL_NT) 725 printf("nested task, "); 726 if (frame->tf_eflags & PSL_RF) 727 printf("resume, "); 728 if (frame->tf_eflags & PSL_VM) 729 printf("vm86, "); 730 printf("IOPL = %d\n", (frame->tf_eflags & PSL_IOPL) >> 12); 731 printf("current process = "); 732 if (curproc) { 733 printf("%lu (%s)\n", 734 (u_long)curproc->p_pid, curproc->p_comm ? 735 curproc->p_comm : ""); 736 } else { 737 printf("Idle\n"); 738 } 739 printf("interrupt mask = "); 740 if ((cpl & net_imask) == net_imask) 741 printf("net "); 742 if ((cpl & tty_imask) == tty_imask) 743 printf("tty "); 744 if ((cpl & bio_imask) == bio_imask) 745 printf("bio "); 746 if (cpl == 0) 747 printf("none"); 748 printf("\n"); 749 750 #ifdef KDB 751 if (kdb_trap(&psl)) 752 return; 753 #endif 754 #ifdef DDB 755 if (kdb_trap (type, 0, frame)) 756 return; 757 #endif 758 if (type <= MAX_TRAP_MSG) 759 panic(trap_msg[type]); 760 else 761 panic("unknown/reserved trap"); 762 } 763 764 /* 765 * Double fault handler. Called when a fault occurs while writing 766 * a frame for a trap/exception onto the stack. This usually occurs 767 * when the stack overflows (such is the case with infinite recursion, 768 * for example). 769 * 770 * XXX Note that the current PTD gets replaced by IdlePTD when the 771 * task switch occurs. This means that the stack that was active at 772 * the time of the double fault is not available at <kstack> unless 773 * the machine was idle when the double fault occurred. The downside 774 * of this is that "trace <ebp>" in ddb won't work. 775 */ 776 void 777 dblfault_handler() 778 { 779 struct pcb *pcb = curpcb; 780 781 if (pcb != NULL) { 782 printf("\nFatal double fault:\n"); 783 printf("eip = 0x%x\n", pcb->pcb_tss.tss_eip); 784 printf("esp = 0x%x\n", pcb->pcb_tss.tss_esp); 785 printf("ebp = 0x%x\n", pcb->pcb_tss.tss_ebp); 786 } 787 788 panic("double fault"); 789 } 790 791 /* 792 * Compensate for 386 brain damage (missing URKR). 793 * This is a little simpler than the pagefault handler in trap() because 794 * it the page tables have already been faulted in and high addresses 795 * are thrown out early for other reasons. 796 */ 797 int trapwrite(addr) 798 unsigned addr; 799 { 800 struct proc *p; 801 vm_offset_t va, v; 802 struct vmspace *vm; 803 int rv; 804 805 va = trunc_page((vm_offset_t)addr); 806 /* 807 * XXX - MAX is END. Changed > to >= for temp. fix. 808 */ 809 if (va >= VM_MAXUSER_ADDRESS) 810 return (1); 811 812 p = curproc; 813 vm = p->p_vmspace; 814 815 ++p->p_lock; 816 817 if ((caddr_t)va >= vm->vm_maxsaddr 818 && (caddr_t)va < (caddr_t)USRSTACK) { 819 if (!grow(p, va)) { 820 --p->p_lock; 821 return (1); 822 } 823 } 824 825 v = trunc_page(vtopte(va)); 826 827 /* 828 * wire the pte page 829 */ 830 if (va < USRSTACK) { 831 vm_map_pageable(&vm->vm_map, v, round_page(v+1), FALSE); 832 } 833 834 /* 835 * fault the data page 836 */ 837 rv = vm_fault(&vm->vm_map, va, VM_PROT_READ|VM_PROT_WRITE, FALSE); 838 839 /* 840 * unwire the pte page 841 */ 842 if (va < USRSTACK) { 843 vm_map_pageable(&vm->vm_map, v, round_page(v+1), TRUE); 844 } 845 846 --p->p_lock; 847 848 if (rv != KERN_SUCCESS) 849 return 1; 850 851 return (0); 852 } 853 854 /* 855 * System call request from POSIX system call gate interface to kernel. 856 * Like trap(), argument is call by reference. 857 */ 858 void 859 syscall(frame) 860 struct trapframe frame; 861 { 862 caddr_t params; 863 int i; 864 struct sysent *callp; 865 struct proc *p = curproc; 866 u_quad_t sticks; 867 int error; 868 int args[8], rval[2]; 869 u_int code; 870 871 sticks = p->p_sticks; 872 if (ISPL(frame.tf_cs) != SEL_UPL) 873 panic("syscall"); 874 875 p->p_md.md_regs = (int *)&frame; 876 params = (caddr_t)frame.tf_esp + sizeof(int); 877 code = frame.tf_eax; 878 /* 879 * Need to check if this is a 32 bit or 64 bit syscall. 880 */ 881 if (code == SYS_syscall) { 882 /* 883 * Code is first argument, followed by actual args. 884 */ 885 code = fuword(params); 886 params += sizeof(int); 887 } else if (code == SYS___syscall) { 888 /* 889 * Like syscall, but code is a quad, so as to maintain 890 * quad alignment for the rest of the arguments. 891 */ 892 code = fuword(params); 893 params += sizeof(quad_t); 894 } 895 896 if (p->p_sysent->sv_mask) 897 code &= p->p_sysent->sv_mask; 898 899 if (code >= p->p_sysent->sv_size) 900 callp = &p->p_sysent->sv_table[0]; 901 else 902 callp = &p->p_sysent->sv_table[code]; 903 904 if ((i = callp->sy_narg * sizeof(int)) && 905 (error = copyin(params, (caddr_t)args, (u_int)i))) { 906 #ifdef KTRACE 907 if (KTRPOINT(p, KTR_SYSCALL)) 908 ktrsyscall(p->p_tracep, code, callp->sy_narg, args); 909 #endif 910 goto bad; 911 } 912 #ifdef KTRACE 913 if (KTRPOINT(p, KTR_SYSCALL)) 914 ktrsyscall(p->p_tracep, code, callp->sy_narg, args); 915 #endif 916 rval[0] = 0; 917 rval[1] = frame.tf_edx; 918 919 error = (*callp->sy_call)(p, args, rval); 920 921 switch (error) { 922 923 case 0: 924 /* 925 * Reinitialize proc pointer `p' as it may be different 926 * if this is a child returning from fork syscall. 927 */ 928 p = curproc; 929 frame.tf_eax = rval[0]; 930 frame.tf_edx = rval[1]; 931 frame.tf_eflags &= ~PSL_C; 932 break; 933 934 case ERESTART: 935 /* 936 * Reconstruct pc, assuming lcall $X,y is 7 bytes. 937 */ 938 frame.tf_eip -= 7; 939 break; 940 941 case EJUSTRETURN: 942 break; 943 944 default: 945 bad: 946 if (p->p_sysent->sv_errsize) 947 if (error >= p->p_sysent->sv_errsize) 948 error = -1; /* XXX */ 949 else 950 error = p->p_sysent->sv_errtbl[error]; 951 frame.tf_eax = error; 952 frame.tf_eflags |= PSL_C; 953 break; 954 } 955 956 if (frame.tf_eflags & PSL_T) { 957 /* Traced syscall. */ 958 frame.tf_eflags &= ~PSL_T; 959 trapsignal(p, SIGTRAP, 0); 960 } 961 962 userret(p, &frame, sticks); 963 964 #ifdef KTRACE 965 if (KTRPOINT(p, KTR_SYSRET)) 966 ktrsysret(p->p_tracep, code, error, rval[0]); 967 #endif 968 } 969 970 #if defined(COMPAT_LINUX) || defined(LINUX) 971 void 972 linux_syscall(frame) 973 struct trapframe frame; 974 { 975 struct proc *p = curproc; 976 struct sysent *callp; 977 u_quad_t sticks; 978 int error; 979 int rval[2]; 980 u_int code; 981 struct linux_syscall_args { 982 int arg1; 983 int arg2; 984 int arg3; 985 int arg4; 986 int arg5; 987 } args; 988 989 args.arg1 = frame.tf_ebx; 990 args.arg2 = frame.tf_ecx; 991 args.arg3 = frame.tf_edx; 992 args.arg4 = frame.tf_esi; 993 args.arg5 = frame.tf_edi; 994 995 sticks = p->p_sticks; 996 if (ISPL(frame.tf_cs) != SEL_UPL) 997 panic("linux syscall"); 998 999 p->p_md.md_regs = (int *)&frame; 1000 code = frame.tf_eax; 1001 1002 if (p->p_sysent->sv_mask) 1003 code &= p->p_sysent->sv_mask; 1004 1005 if (code >= p->p_sysent->sv_size) 1006 callp = &p->p_sysent->sv_table[0]; 1007 else 1008 callp = &p->p_sysent->sv_table[code]; 1009 1010 #ifdef KTRACE 1011 if (KTRPOINT(p, KTR_SYSCALL)) 1012 ktrsyscall(p->p_tracep, code, callp->sy_narg, (int *)&args); 1013 #endif 1014 1015 rval[0] = 0; 1016 1017 error = (*callp->sy_call)(p, &args, rval); 1018 1019 switch (error) { 1020 1021 case 0: 1022 /* 1023 * Reinitialize proc pointer `p' as it may be different 1024 * if this is a child returning from fork syscall. 1025 */ 1026 p = curproc; 1027 frame.tf_eax = rval[0]; 1028 frame.tf_eflags &= ~PSL_C; 1029 break; 1030 1031 case ERESTART: 1032 /* Reconstruct pc, subtract size of int 0x80 */ 1033 frame.tf_eip -= 2; 1034 break; 1035 1036 case EJUSTRETURN: 1037 break; 1038 1039 default: 1040 if (p->p_sysent->sv_errsize) 1041 if (error >= p->p_sysent->sv_errsize) 1042 error = -1; /* XXX */ 1043 else 1044 error = p->p_sysent->sv_errtbl[error]; 1045 frame.tf_eax = -error; 1046 frame.tf_eflags |= PSL_C; 1047 break; 1048 } 1049 1050 if (frame.tf_eflags & PSL_T) { 1051 /* Traced syscall. */ 1052 frame.tf_eflags &= ~PSL_T; 1053 trapsignal(p, SIGTRAP, 0); 1054 } 1055 1056 userret(p, &frame, sticks); 1057 1058 #ifdef KTRACE 1059 if (KTRPOINT(p, KTR_SYSRET)) 1060 ktrsysret(p->p_tracep, code, error, rval[0]); 1061 #endif 1062 } 1063 #endif /* COMPAT_LINUX || LINUX */ 1064