subr_syscall.c revision 5603
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 1.43 1995/01/09 16:04:39 davidg Exp $ 39 */ 40 41/* 42 * 386 Trap and System call handling 43 */ 44 45#include <sys/param.h> 46#include <sys/systm.h> 47#include <sys/proc.h> 48#include <sys/user.h> 49#include <sys/acct.h> 50#include <sys/kernel.h> 51#include <sys/syscall.h> 52#include <sys/sysent.h> 53#ifdef KTRACE 54#include <sys/ktrace.h> 55#endif 56 57#include <vm/vm_param.h> 58#include <vm/pmap.h> 59#include <vm/vm_map.h> 60#include <vm/vm_page.h> 61 62#include <machine/cpu.h> 63#include <machine/psl.h> 64#include <machine/reg.h> 65#include <machine/trap.h> 66#include <machine/../isa/isa_device.h> 67 68#include "isa.h" 69#include "npx.h" 70 71int trap_pfault __P((struct trapframe *, int)); 72void trap_fatal __P((struct trapframe *)); 73 74#define MAX_TRAP_MSG 27 75char *trap_msg[] = { 76 "", /* 0 unused */ 77 "privileged instruction fault", /* 1 T_PRIVINFLT */ 78 "", /* 2 unused */ 79 "breakpoint instruction fault", /* 3 T_BPTFLT */ 80 "", /* 4 unused */ 81 "", /* 5 unused */ 82 "arithmetic trap", /* 6 T_ARITHTRAP */ 83 "system forced exception", /* 7 T_ASTFLT */ 84 "", /* 8 unused */ 85 "general protection fault", /* 9 T_PROTFLT */ 86 "trace trap", /* 10 T_TRCTRAP */ 87 "", /* 11 unused */ 88 "page fault", /* 12 T_PAGEFLT */ 89 "", /* 13 unused */ 90 "alignment fault", /* 14 T_ALIGNFLT */ 91 "", /* 15 unused */ 92 "", /* 16 unused */ 93 "", /* 17 unused */ 94 "integer divide fault", /* 18 T_DIVIDE */ 95 "non-maskable interrupt trap", /* 19 T_NMI */ 96 "overflow trap", /* 20 T_OFLOW */ 97 "FPU bounds check fault", /* 21 T_BOUND */ 98 "FPU device not available", /* 22 T_DNA */ 99 "double fault", /* 23 T_DOUBLEFLT */ 100 "FPU operand fetch fault", /* 24 T_FPOPFLT */ 101 "invalid TSS fault", /* 25 T_TSSFLT */ 102 "segment not present fault", /* 26 T_SEGNPFLT */ 103 "stack fault", /* 27 T_STKFLT */ 104}; 105 106static inline void 107userret(p, frame, oticks) 108 struct proc *p; 109 struct trapframe *frame; 110 u_quad_t oticks; 111{ 112 int sig, s; 113 114 while ((sig = CURSIG(p)) != 0) 115 postsig(sig); 116 p->p_priority = p->p_usrpri; 117 if (want_resched) { 118 /* 119 * Since we are curproc, clock will normally just change 120 * our priority without moving us from one queue to another 121 * (since the running process is not on a queue.) 122 * If that happened after we setrunqueue ourselves but before we 123 * mi_switch()'ed, we might not be on the queue indicated by 124 * our priority. 125 */ 126 s = splclock(); 127 setrunqueue(p); 128 p->p_stats->p_ru.ru_nivcsw++; 129 mi_switch(); 130 splx(s); 131 while ((sig = CURSIG(p)) != 0) 132 postsig(sig); 133 } 134 if (p->p_stats->p_prof.pr_scale) { 135 u_quad_t ticks = p->p_sticks - oticks; 136 137 if (ticks) { 138#ifdef PROFTIMER 139 extern int profscale; 140 addupc(frame->tf_eip, &p->p_stats->p_prof, 141 ticks * profscale); 142#else 143 addupc(frame->tf_eip, &p->p_stats->p_prof, ticks); 144#endif 145 } 146 } 147 curpriority = p->p_priority; 148} 149 150/* 151 * trap(frame): 152 * Exception, fault, and trap interface to the FreeBSD kernel. 153 * This common code is called from assembly language IDT gate entry 154 * routines that prepare a suitable stack frame, and restore this 155 * frame after the exception has been processed. 156 */ 157 158/*ARGSUSED*/ 159void 160trap(frame) 161 struct trapframe frame; 162{ 163 struct proc *p = curproc; 164 u_quad_t sticks = 0; 165 int i = 0, ucode = 0, type, code; 166#ifdef DIAGNOSTIC 167 u_long eva; 168#endif 169 170 type = frame.tf_trapno; 171 code = frame.tf_err; 172 173 if (ISPL(frame.tf_cs) == SEL_UPL) { 174 /* user trap */ 175 176 sticks = p->p_sticks; 177 p->p_md.md_regs = (int *)&frame; 178 179 switch (type) { 180 case T_PRIVINFLT: /* privileged instruction fault */ 181 ucode = type; 182 i = SIGILL; 183 break; 184 185 case T_BPTFLT: /* bpt instruction fault */ 186 case T_TRCTRAP: /* trace trap */ 187 frame.tf_eflags &= ~PSL_T; 188 i = SIGTRAP; 189 break; 190 191 case T_ARITHTRAP: /* arithmetic trap */ 192 ucode = code; 193 i = SIGFPE; 194 break; 195 196 case T_ASTFLT: /* Allow process switch */ 197 astoff(); 198 cnt.v_soft++; 199 if ((p->p_flag & P_OWEUPC) && p->p_stats->p_prof.pr_scale) { 200 addupc(frame.tf_eip, &p->p_stats->p_prof, 1); 201 p->p_flag &= ~P_OWEUPC; 202 } 203 goto out; 204 205 case T_PROTFLT: /* general protection fault */ 206 case T_SEGNPFLT: /* segment not present fault */ 207 case T_STKFLT: /* stack fault */ 208 case T_TSSFLT: /* invalid TSS fault */ 209 case T_DOUBLEFLT: /* double fault */ 210 default: 211 ucode = code + BUS_SEGM_FAULT ; 212 i = SIGBUS; 213 break; 214 215 case T_PAGEFLT: /* page fault */ 216 i = trap_pfault(&frame, TRUE); 217 if (i == -1) 218 return; 219 if (i == 0) 220 goto out; 221 222 ucode = T_PAGEFLT; 223 break; 224 225 case T_DIVIDE: /* integer divide fault */ 226 ucode = FPE_INTDIV_TRAP; 227 i = SIGFPE; 228 break; 229 230#if NISA > 0 231 case T_NMI: 232#ifdef DDB 233 /* NMI can be hooked up to a pushbutton for debugging */ 234 printf ("NMI ... going to debugger\n"); 235 if (kdb_trap (type, 0, &frame)) 236 return; 237#endif 238 /* machine/parity/power fail/"kitchen sink" faults */ 239 if (isa_nmi(code) == 0) return; 240 panic("NMI indicates hardware failure"); 241#endif 242 243 case T_OFLOW: /* integer overflow fault */ 244 ucode = FPE_INTOVF_TRAP; 245 i = SIGFPE; 246 break; 247 248 case T_BOUND: /* bounds check fault */ 249 ucode = FPE_SUBRNG_TRAP; 250 i = SIGFPE; 251 break; 252 253 case T_DNA: 254#if NNPX > 0 255 /* if a transparent fault (due to context switch "late") */ 256 if (npxdna()) 257 return; 258#endif /* NNPX > 0 */ 259 260#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE) 261 i = math_emulate(&frame); 262 if (i == 0) { 263 if (!(frame.tf_eflags & PSL_T)) 264 return; 265 frame.tf_eflags &= ~PSL_T; 266 i = SIGTRAP; 267 } 268 /* else ucode = emulator_only_knows() XXX */ 269#else /* MATH_EMULATE || GPL_MATH_EMULATE */ 270 i = SIGFPE; 271 ucode = FPE_FPU_NP_TRAP; 272#endif /* MATH_EMULATE || GPL_MATH_EMULATE */ 273 break; 274 275 case T_FPOPFLT: /* FPU operand fetch fault */ 276 ucode = T_FPOPFLT; 277 i = SIGILL; 278 break; 279 } 280 } else { 281 /* kernel trap */ 282 283 switch (type) { 284 case T_PAGEFLT: /* page fault */ 285 (void) trap_pfault(&frame, FALSE); 286 return; 287 288 case T_PROTFLT: /* general protection fault */ 289 case T_SEGNPFLT: /* segment not present fault */ 290 /* 291 * Invalid segment selectors and out of bounds 292 * %eip's and %esp's can be set up in user mode. 293 * This causes a fault in kernel mode when the 294 * kernel tries to return to user mode. We want 295 * to get this fault so that we can fix the 296 * problem here and not have to check all the 297 * selectors and pointers when the user changes 298 * them. 299 */ 300#define MAYBE_DORETI_FAULT(where, whereto) \ 301 do { \ 302 extern void where(void) __asm(__STRING(where)); \ 303 extern void whereto(void) __asm(__STRING(whereto)); \ 304 if (frame.tf_eip == (int)where) { \ 305 frame.tf_eip = (int)whereto; \ 306 return; \ 307 } \ 308 } while (0) 309 310 if (intr_nesting_level == 0) { 311 MAYBE_DORETI_FAULT(doreti_iret, 312 doreti_iret_fault); 313 MAYBE_DORETI_FAULT(doreti_popl_ds, 314 doreti_popl_ds_fault); 315 MAYBE_DORETI_FAULT(doreti_popl_es, 316 doreti_popl_es_fault); 317 } 318 if (curpcb && curpcb->pcb_onfault) { 319 frame.tf_eip = (int)curpcb->pcb_onfault; 320 return; 321 } 322 break; 323 324 case T_TSSFLT: 325 /* 326 * PSL_NT can be set in user mode and isn't cleared 327 * automatically when the kernel is entered. This 328 * causes a TSS fault when the kernel attempts to 329 * `iret' because the TSS link is uninitialized. We 330 * want to get this fault so that we can fix the 331 * problem here and not every time the kernel is 332 * entered. 333 */ 334 if (frame.tf_eflags & PSL_NT) { 335 frame.tf_eflags &= ~PSL_NT; 336 return; 337 } 338 break; 339 340#ifdef DDB 341 case T_BPTFLT: 342 case T_TRCTRAP: 343 if (kdb_trap (type, 0, &frame)) 344 return; 345 break; 346#else 347 case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */ 348 /* Q: how do we turn it on again? */ 349 frame.tf_eflags &= ~PSL_T; 350 return; 351#endif 352 353#if NISA > 0 354 case T_NMI: 355#ifdef DDB 356 /* NMI can be hooked up to a pushbutton for debugging */ 357 printf ("NMI ... going to debugger\n"); 358 if (kdb_trap (type, 0, &frame)) 359 return; 360#endif 361 /* machine/parity/power fail/"kitchen sink" faults */ 362 if (isa_nmi(code) == 0) return; 363 /* FALL THROUGH */ 364#endif 365 } 366 367 trap_fatal(&frame); 368 return; 369 } 370 371 trapsignal(p, i, ucode); 372 373#ifdef DIAGNOSTIC 374 eva = rcr2(); 375 if (type <= MAX_TRAP_MSG) { 376 uprintf("fatal process exception: %s", 377 trap_msg[type]); 378 if ((type == T_PAGEFLT) || (type == T_PROTFLT)) 379 uprintf(", fault VA = 0x%x", eva); 380 uprintf("\n"); 381 } 382#endif 383 384out: 385 userret(p, &frame, sticks); 386} 387 388int 389trap_pfault(frame, usermode) 390 struct trapframe *frame; 391 int usermode; 392{ 393 vm_offset_t va; 394 struct vmspace *vm = NULL; 395 vm_map_t map = 0; 396 int rv = 0; 397 vm_prot_t ftype; 398 extern vm_map_t kernel_map; 399 int eva; 400 struct proc *p = curproc; 401 402 eva = rcr2(); 403 va = trunc_page((vm_offset_t)eva); 404 405 if (va >= KERNBASE) { 406 /* 407 * Don't allow user-mode faults in kernel address space. 408 */ 409 if (usermode) 410 goto nogo; 411 412 map = kernel_map; 413 } else { 414 /* 415 * This is a fault on non-kernel virtual memory. 416 * vm is initialized above to NULL. If curproc is NULL 417 * or curproc->p_vmspace is NULL the fault is fatal. 418 */ 419 if (p != NULL) 420 vm = p->p_vmspace; 421 422 if (vm == NULL) 423 goto nogo; 424 425 map = &vm->vm_map; 426 } 427 428 if (frame->tf_err & PGEX_W) 429 ftype = VM_PROT_READ | VM_PROT_WRITE; 430 else 431 ftype = VM_PROT_READ; 432 433 if (map != kernel_map) { 434 vm_offset_t v = (vm_offset_t) vtopte(va); 435 vm_page_t ptepg; 436 437 /* 438 * Keep swapout from messing with us during this 439 * critical time. 440 */ 441 ++p->p_lock; 442 443 /* 444 * Grow the stack if necessary 445 */ 446 if ((caddr_t)va > vm->vm_maxsaddr 447 && (caddr_t)va < (caddr_t)USRSTACK) { 448 if (!grow(p, va)) { 449 rv = KERN_FAILURE; 450 --p->p_lock; 451 goto nogo; 452 } 453 } 454 455 /* 456 * Check if page table is mapped, if not, 457 * fault it first 458 */ 459 460 /* Fault the pte only if needed: */ 461 *(volatile char *)v += 0; 462 463 ptepg = (vm_page_t) pmap_pte_vm_page(vm_map_pmap(map), v); 464 vm_page_hold(ptepg); 465 466 /* Fault in the user page: */ 467 rv = vm_fault(map, va, ftype, FALSE); 468 469 vm_page_unhold(ptepg); 470 471 /* 472 * page table pages don't need to be kept if they 473 * are not held 474 */ 475 if( ptepg->hold_count == 0 && ptepg->wire_count == 0) { 476 pmap_page_protect( VM_PAGE_TO_PHYS(ptepg), 477 VM_PROT_NONE); 478 vm_page_free(ptepg); 479 } 480 481 --p->p_lock; 482 } else { 483 /* 484 * Since we know that kernel virtual address addresses 485 * always have pte pages mapped, we just have to fault 486 * the page. 487 */ 488 rv = vm_fault(map, va, ftype, FALSE); 489 } 490 491 if (rv == KERN_SUCCESS) 492 return (0); 493nogo: 494 if (!usermode) { 495 if (curpcb && curpcb->pcb_onfault) { 496 frame->tf_eip = (int)curpcb->pcb_onfault; 497 return (0); 498 } 499 trap_fatal(frame); 500 return (-1); 501 } 502 503 /* kludge to pass faulting virtual address to sendsig */ 504 frame->tf_err = eva; 505 506 return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV); 507} 508 509void 510trap_fatal(frame) 511 struct trapframe *frame; 512{ 513 int code, type, eva; 514 struct soft_segment_descriptor softseg; 515 516 code = frame->tf_err; 517 type = frame->tf_trapno; 518 eva = rcr2(); 519 sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)].sd, &softseg); 520 521 if (type <= MAX_TRAP_MSG) 522 printf("\n\nFatal trap %d: %s while in %s mode\n", 523 type, trap_msg[type], 524 ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel"); 525 if (type == T_PAGEFLT) { 526 printf("fault virtual address = 0x%x\n", eva); 527 printf("fault code = %s %s, %s\n", 528 code & PGEX_U ? "user" : "supervisor", 529 code & PGEX_W ? "write" : "read", 530 code & PGEX_P ? "protection violation" : "page not present"); 531 } 532 printf("instruction pointer = 0x%x:0x%x\n", frame->tf_cs & 0xffff, frame->tf_eip); 533 printf("code segment = base 0x%x, limit 0x%x, type 0x%x\n", 534 softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type); 535 printf(" = DPL %d, pres %d, def32 %d, gran %d\n", 536 softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_def32, softseg.ssd_gran); 537 printf("processor eflags = "); 538 if (frame->tf_eflags & PSL_T) 539 printf("trace/trap, "); 540 if (frame->tf_eflags & PSL_I) 541 printf("interrupt enabled, "); 542 if (frame->tf_eflags & PSL_NT) 543 printf("nested task, "); 544 if (frame->tf_eflags & PSL_RF) 545 printf("resume, "); 546 if (frame->tf_eflags & PSL_VM) 547 printf("vm86, "); 548 printf("IOPL = %d\n", (frame->tf_eflags & PSL_IOPL) >> 12); 549 printf("current process = "); 550 if (curproc) { 551 printf("%lu (%s)\n", 552 (u_long)curproc->p_pid, curproc->p_comm ? 553 curproc->p_comm : ""); 554 } else { 555 printf("Idle\n"); 556 } 557 printf("interrupt mask = "); 558 if ((cpl & net_imask) == net_imask) 559 printf("net "); 560 if ((cpl & tty_imask) == tty_imask) 561 printf("tty "); 562 if ((cpl & bio_imask) == bio_imask) 563 printf("bio "); 564 if (cpl == 0) 565 printf("none"); 566 printf("\n"); 567 568#ifdef KDB 569 if (kdb_trap(&psl)) 570 return; 571#endif 572#ifdef DDB 573 if (kdb_trap (type, 0, frame)) 574 return; 575#endif 576 if (type <= MAX_TRAP_MSG) 577 panic(trap_msg[type]); 578 else 579 panic("unknown/reserved trap"); 580} 581 582/* 583 * Compensate for 386 brain damage (missing URKR). 584 * This is a little simpler than the pagefault handler in trap() because 585 * it the page tables have already been faulted in and high addresses 586 * are thrown out early for other reasons. 587 */ 588int trapwrite(addr) 589 unsigned addr; 590{ 591 struct proc *p; 592 vm_offset_t va, v; 593 struct vmspace *vm; 594 int rv; 595 596 va = trunc_page((vm_offset_t)addr); 597 /* 598 * XXX - MAX is END. Changed > to >= for temp. fix. 599 */ 600 if (va >= VM_MAXUSER_ADDRESS) 601 return (1); 602 603 p = curproc; 604 vm = p->p_vmspace; 605 606 ++p->p_lock; 607 608 if ((caddr_t)va >= vm->vm_maxsaddr 609 && (caddr_t)va < (caddr_t)USRSTACK) { 610 if (!grow(p, va)) { 611 --p->p_lock; 612 return (1); 613 } 614 } 615 616 v = trunc_page(vtopte(va)); 617 618 /* 619 * wire the pte page 620 */ 621 if (va < USRSTACK) { 622 vm_map_pageable(&vm->vm_map, v, round_page(v+1), FALSE); 623 } 624 625 /* 626 * fault the data page 627 */ 628 rv = vm_fault(&vm->vm_map, va, VM_PROT_READ|VM_PROT_WRITE, FALSE); 629 630 /* 631 * unwire the pte page 632 */ 633 if (va < USRSTACK) { 634 vm_map_pageable(&vm->vm_map, v, round_page(v+1), TRUE); 635 } 636 637 --p->p_lock; 638 639 if (rv != KERN_SUCCESS) 640 return 1; 641 642 return (0); 643} 644 645/* 646 * syscall(frame): 647 * System call request from POSIX system call gate interface to kernel. 648 * Like trap(), argument is call by reference. 649 */ 650/*ARGSUSED*/ 651void 652syscall(frame) 653 struct trapframe frame; 654{ 655 caddr_t params; 656 int i; 657 struct sysent *callp; 658 struct proc *p = curproc; 659 u_quad_t sticks; 660 int error, opc; 661 int args[8], rval[2]; 662 u_int code; 663 664 sticks = p->p_sticks; 665 if (ISPL(frame.tf_cs) != SEL_UPL) 666 panic("syscall"); 667 668 code = frame.tf_eax; 669 p->p_md.md_regs = (int *)&frame; 670 params = (caddr_t)frame.tf_esp + sizeof (int) ; 671 672 /* 673 * Reconstruct pc, assuming lcall $X,y is 7 bytes, as it is always. 674 */ 675 opc = frame.tf_eip - 7; 676 /* 677 * Need to check if this is a 32 bit or 64 bit syscall. 678 */ 679 if (code == SYS_syscall) { 680 /* 681 * Code is first argument, followed by actual args. 682 */ 683 code = fuword(params); 684 params += sizeof (int); 685 } else if (code == SYS___syscall) { 686 /* 687 * Like syscall, but code is a quad, so as to maintain 688 * quad alignment for the rest of the arguments. 689 */ 690 code = fuword(params + _QUAD_LOWWORD * sizeof(int)); 691 params += sizeof(quad_t); 692 } 693 694 if (p->p_sysent->sv_mask) 695 code = code & p->p_sysent->sv_mask; 696 697 if (code >= p->p_sysent->sv_size) 698 callp = &p->p_sysent->sv_table[0]; 699 else 700 callp = &p->p_sysent->sv_table[code]; 701 702 if ((i = callp->sy_narg * sizeof (int)) && 703 (error = copyin(params, (caddr_t)args, (u_int)i))) { 704#ifdef KTRACE 705 if (KTRPOINT(p, KTR_SYSCALL)) 706 ktrsyscall(p->p_tracep, code, callp->sy_narg, args); 707#endif 708 goto bad; 709 } 710#ifdef KTRACE 711 if (KTRPOINT(p, KTR_SYSCALL)) 712 ktrsyscall(p->p_tracep, code, callp->sy_narg, args); 713#endif 714 rval[0] = 0; 715 rval[1] = frame.tf_edx; 716 717 error = (*callp->sy_call)(p, args, rval); 718 719 switch (error) { 720 721 case 0: 722 /* 723 * Reinitialize proc pointer `p' as it may be different 724 * if this is a child returning from fork syscall. 725 */ 726 p = curproc; 727 frame.tf_eax = rval[0]; 728 frame.tf_edx = rval[1]; 729 frame.tf_eflags &= ~PSL_C; /* carry bit */ 730 break; 731 732 case ERESTART: 733 frame.tf_eip = opc; 734 break; 735 736 case EJUSTRETURN: 737 break; 738 739 default: 740 bad: 741 if (p->p_sysent->sv_errsize) 742 if (error >= p->p_sysent->sv_errsize) 743 error = -1; /* XXX */ 744 else 745 error = p->p_sysent->sv_errtbl[error]; 746 frame.tf_eax = error; 747 frame.tf_eflags |= PSL_C; /* carry bit */ 748 break; 749 } 750 751 userret(p, &frame, sticks); 752 753#ifdef KTRACE 754 if (KTRPOINT(p, KTR_SYSRET)) 755 ktrsysret(p->p_tracep, code, error, rval[0]); 756#endif 757} 758