Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/amd64/amd64/sys_machdep.c
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1 /*- 2 * Copyright (c) 2003 Peter Wemm. 3 * Copyright (c) 1990 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 4. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * from: @(#)sys_machdep.c 5.5 (Berkeley) 1/19/91 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD: releng/8.1/sys/amd64/amd64/sys_machdep.c 202421 2010-01-15 22:19:51Z kib $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/lock.h> 39 #include <sys/malloc.h> 40 #include <sys/mutex.h> 41 #include <sys/priv.h> 42 #include <sys/proc.h> 43 #include <sys/sysproto.h> 44 #include <sys/uio.h> 45 46 #include <vm/vm.h> 47 #include <vm/pmap.h> 48 #include <vm/vm_kern.h> /* for kernel_map */ 49 #include <vm/vm_extern.h> 50 51 #include <machine/frame.h> 52 #include <machine/md_var.h> 53 #include <machine/pcb.h> 54 #include <machine/specialreg.h> 55 #include <machine/sysarch.h> 56 #include <machine/tss.h> 57 #include <machine/vmparam.h> 58 59 #include <security/audit/audit.h> 60 61 int max_ldt_segment = 1024; 62 #define LD_PER_PAGE 512 63 #define NULL_LDT_BASE ((caddr_t)NULL) 64 65 #ifdef notyet 66 #ifdef SMP 67 static void set_user_ldt_rv(struct vmspace *vmsp); 68 #endif 69 #endif 70 static void user_ldt_derefl(struct proc_ldt *pldt); 71 72 #ifndef _SYS_SYSPROTO_H_ 73 struct sysarch_args { 74 int op; 75 char *parms; 76 }; 77 #endif 78 79 int 80 sysarch_ldt(struct thread *td, struct sysarch_args *uap, int uap_space) 81 { 82 struct i386_ldt_args *largs, la; 83 struct user_segment_descriptor *lp; 84 int error = 0; 85 86 /* 87 * XXXKIB check that the BSM generation code knows to encode 88 * the op argument. 89 */ 90 AUDIT_ARG_CMD(uap->op); 91 if (uap_space == UIO_USERSPACE) { 92 error = copyin(uap->parms, &la, sizeof(struct i386_ldt_args)); 93 if (error != 0) 94 return (error); 95 largs = &la; 96 } else 97 largs = (struct i386_ldt_args *)uap->parms; 98 if (largs->num > max_ldt_segment || largs->num <= 0) 99 return (EINVAL); 100 101 switch (uap->op) { 102 case I386_GET_LDT: 103 error = amd64_get_ldt(td, largs); 104 break; 105 case I386_SET_LDT: 106 td->td_pcb->pcb_full_iret = 1; 107 if (largs->descs != NULL) { 108 lp = (struct user_segment_descriptor *) 109 kmem_alloc(kernel_map, largs->num * 110 sizeof(struct user_segment_descriptor)); 111 if (lp == NULL) { 112 error = ENOMEM; 113 break; 114 } 115 error = copyin(largs->descs, lp, largs->num * 116 sizeof(struct user_segment_descriptor)); 117 if (error == 0) 118 error = amd64_set_ldt(td, largs, lp); 119 kmem_free(kernel_map, (vm_offset_t)lp, largs->num * 120 sizeof(struct user_segment_descriptor)); 121 } else { 122 error = amd64_set_ldt(td, largs, NULL); 123 } 124 break; 125 } 126 return (error); 127 } 128 129 void 130 update_gdt_gsbase(struct thread *td, uint32_t base) 131 { 132 struct user_segment_descriptor *sd; 133 134 if (td != curthread) 135 return; 136 td->td_pcb->pcb_full_iret = 1; 137 critical_enter(); 138 sd = PCPU_GET(gs32p); 139 sd->sd_lobase = base & 0xffffff; 140 sd->sd_hibase = (base >> 24) & 0xff; 141 critical_exit(); 142 } 143 144 void 145 update_gdt_fsbase(struct thread *td, uint32_t base) 146 { 147 struct user_segment_descriptor *sd; 148 149 if (td != curthread) 150 return; 151 td->td_pcb->pcb_full_iret = 1; 152 critical_enter(); 153 sd = PCPU_GET(fs32p); 154 sd->sd_lobase = base & 0xffffff; 155 sd->sd_hibase = (base >> 24) & 0xff; 156 critical_exit(); 157 } 158 159 int 160 sysarch(td, uap) 161 struct thread *td; 162 register struct sysarch_args *uap; 163 { 164 int error = 0; 165 struct pcb *pcb = curthread->td_pcb; 166 uint32_t i386base; 167 uint64_t a64base; 168 struct i386_ioperm_args iargs; 169 170 if (uap->op == I386_GET_LDT || uap->op == I386_SET_LDT) 171 return (sysarch_ldt(td, uap, UIO_USERSPACE)); 172 /* 173 * XXXKIB check that the BSM generation code knows to encode 174 * the op argument. 175 */ 176 AUDIT_ARG_CMD(uap->op); 177 switch (uap->op) { 178 case I386_GET_IOPERM: 179 case I386_SET_IOPERM: 180 if ((error = copyin(uap->parms, &iargs, 181 sizeof(struct i386_ioperm_args))) != 0) 182 return (error); 183 break; 184 default: 185 break; 186 } 187 188 switch (uap->op) { 189 case I386_GET_IOPERM: 190 error = amd64_get_ioperm(td, &iargs); 191 if (error == 0) 192 error = copyout(&iargs, uap->parms, 193 sizeof(struct i386_ioperm_args)); 194 break; 195 case I386_SET_IOPERM: 196 error = amd64_set_ioperm(td, &iargs); 197 break; 198 case I386_GET_FSBASE: 199 i386base = pcb->pcb_fsbase; 200 error = copyout(&i386base, uap->parms, sizeof(i386base)); 201 break; 202 case I386_SET_FSBASE: 203 error = copyin(uap->parms, &i386base, sizeof(i386base)); 204 if (!error) { 205 pcb->pcb_fsbase = i386base; 206 td->td_frame->tf_fs = _ufssel; 207 pcb->pcb_full_iret = 1; 208 update_gdt_fsbase(td, i386base); 209 } 210 break; 211 case I386_GET_GSBASE: 212 i386base = pcb->pcb_gsbase; 213 error = copyout(&i386base, uap->parms, sizeof(i386base)); 214 break; 215 case I386_SET_GSBASE: 216 error = copyin(uap->parms, &i386base, sizeof(i386base)); 217 if (!error) { 218 pcb->pcb_gsbase = i386base; 219 pcb->pcb_full_iret = 1; 220 td->td_frame->tf_gs = _ugssel; 221 update_gdt_gsbase(td, i386base); 222 } 223 break; 224 case AMD64_GET_FSBASE: 225 error = copyout(&pcb->pcb_fsbase, uap->parms, sizeof(pcb->pcb_fsbase)); 226 break; 227 228 case AMD64_SET_FSBASE: 229 error = copyin(uap->parms, &a64base, sizeof(a64base)); 230 if (!error) { 231 if (a64base < VM_MAXUSER_ADDRESS) { 232 pcb->pcb_fsbase = a64base; 233 pcb->pcb_full_iret = 1; 234 td->td_frame->tf_fs = _ufssel; 235 } else 236 error = EINVAL; 237 } 238 break; 239 240 case AMD64_GET_GSBASE: 241 error = copyout(&pcb->pcb_gsbase, uap->parms, sizeof(pcb->pcb_gsbase)); 242 break; 243 244 case AMD64_SET_GSBASE: 245 error = copyin(uap->parms, &a64base, sizeof(a64base)); 246 if (!error) { 247 if (a64base < VM_MAXUSER_ADDRESS) { 248 pcb->pcb_gsbase = a64base; 249 pcb->pcb_full_iret = 1; 250 td->td_frame->tf_gs = _ugssel; 251 } else 252 error = EINVAL; 253 } 254 break; 255 256 default: 257 error = EINVAL; 258 break; 259 } 260 return (error); 261 } 262 263 int 264 amd64_set_ioperm(td, uap) 265 struct thread *td; 266 struct i386_ioperm_args *uap; 267 { 268 int i, error; 269 char *iomap; 270 struct amd64tss *tssp; 271 struct system_segment_descriptor *tss_sd; 272 u_long *addr; 273 struct pcb *pcb; 274 275 if ((error = priv_check(td, PRIV_IO)) != 0) 276 return (error); 277 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 278 return (error); 279 if (uap->start + uap->length > IOPAGES * PAGE_SIZE * NBBY) 280 return (EINVAL); 281 282 /* 283 * XXX 284 * While this is restricted to root, we should probably figure out 285 * whether any other driver is using this i/o address, as so not to 286 * cause confusion. This probably requires a global 'usage registry'. 287 */ 288 pcb = td->td_pcb; 289 if (pcb->pcb_tssp == NULL) { 290 tssp = (struct amd64tss *)kmem_alloc(kernel_map, 291 ctob(IOPAGES+1)); 292 if (tssp == NULL) 293 return (ENOMEM); 294 iomap = (char *)&tssp[1]; 295 addr = (u_long *)iomap; 296 for (i = 0; i < (ctob(IOPAGES) + 1) / sizeof(u_long); i++) 297 *addr++ = ~0; 298 critical_enter(); 299 /* Takes care of tss_rsp0. */ 300 memcpy(tssp, &common_tss[PCPU_GET(cpuid)], 301 sizeof(struct amd64tss)); 302 tssp->tss_iobase = sizeof(*tssp); 303 pcb->pcb_tssp = tssp; 304 tss_sd = PCPU_GET(tss); 305 tss_sd->sd_lobase = (u_long)tssp & 0xffffff; 306 tss_sd->sd_hibase = ((u_long)tssp >> 24) & 0xfffffffffful; 307 tss_sd->sd_type = SDT_SYSTSS; 308 ltr(GSEL(GPROC0_SEL, SEL_KPL)); 309 PCPU_SET(tssp, tssp); 310 critical_exit(); 311 } else 312 iomap = (char *)&pcb->pcb_tssp[1]; 313 for (i = uap->start; i < uap->start + uap->length; i++) { 314 if (uap->enable) 315 iomap[i >> 3] &= ~(1 << (i & 7)); 316 else 317 iomap[i >> 3] |= (1 << (i & 7)); 318 } 319 return (error); 320 } 321 322 int 323 amd64_get_ioperm(td, uap) 324 struct thread *td; 325 struct i386_ioperm_args *uap; 326 { 327 int i, state; 328 char *iomap; 329 330 if (uap->start >= IOPAGES * PAGE_SIZE * NBBY) 331 return (EINVAL); 332 if (td->td_pcb->pcb_tssp == NULL) { 333 uap->length = 0; 334 goto done; 335 } 336 337 iomap = (char *)&td->td_pcb->pcb_tssp[1]; 338 339 i = uap->start; 340 state = (iomap[i >> 3] >> (i & 7)) & 1; 341 uap->enable = !state; 342 uap->length = 1; 343 344 for (i = uap->start + 1; i < IOPAGES * PAGE_SIZE * NBBY; i++) { 345 if (state != ((iomap[i >> 3] >> (i & 7)) & 1)) 346 break; 347 uap->length++; 348 } 349 350 done: 351 return (0); 352 } 353 354 /* 355 * Update the GDT entry pointing to the LDT to point to the LDT of the 356 * current process. 357 */ 358 void 359 set_user_ldt(struct mdproc *mdp) 360 { 361 362 critical_enter(); 363 *PCPU_GET(ldt) = mdp->md_ldt_sd; 364 lldt(GSEL(GUSERLDT_SEL, SEL_KPL)); 365 critical_exit(); 366 } 367 368 #ifdef notyet 369 #ifdef SMP 370 static void 371 set_user_ldt_rv(struct vmspace *vmsp) 372 { 373 struct thread *td; 374 375 td = curthread; 376 if (vmsp != td->td_proc->p_vmspace) 377 return; 378 379 set_user_ldt(&td->td_proc->p_md); 380 } 381 #endif 382 #endif 383 384 struct proc_ldt * 385 user_ldt_alloc(struct proc *p, int force) 386 { 387 struct proc_ldt *pldt, *new_ldt; 388 struct mdproc *mdp; 389 struct soft_segment_descriptor sldt; 390 391 mtx_assert(&dt_lock, MA_OWNED); 392 mdp = &p->p_md; 393 if (!force && mdp->md_ldt != NULL) 394 return (mdp->md_ldt); 395 mtx_unlock(&dt_lock); 396 new_ldt = malloc(sizeof(struct proc_ldt), M_SUBPROC, M_WAITOK); 397 new_ldt->ldt_base = (caddr_t)kmem_alloc(kernel_map, 398 max_ldt_segment * sizeof(struct user_segment_descriptor)); 399 if (new_ldt->ldt_base == NULL) { 400 FREE(new_ldt, M_SUBPROC); 401 mtx_lock(&dt_lock); 402 return (NULL); 403 } 404 new_ldt->ldt_refcnt = 1; 405 sldt.ssd_base = (uint64_t)new_ldt->ldt_base; 406 sldt.ssd_limit = max_ldt_segment * 407 sizeof(struct user_segment_descriptor) - 1; 408 sldt.ssd_type = SDT_SYSLDT; 409 sldt.ssd_dpl = SEL_KPL; 410 sldt.ssd_p = 1; 411 sldt.ssd_long = 0; 412 sldt.ssd_def32 = 0; 413 sldt.ssd_gran = 0; 414 mtx_lock(&dt_lock); 415 pldt = mdp->md_ldt; 416 if (pldt != NULL && !force) { 417 kmem_free(kernel_map, (vm_offset_t)new_ldt->ldt_base, 418 max_ldt_segment * sizeof(struct user_segment_descriptor)); 419 free(new_ldt, M_SUBPROC); 420 return (pldt); 421 } 422 423 if (pldt != NULL) { 424 bcopy(pldt->ldt_base, new_ldt->ldt_base, max_ldt_segment * 425 sizeof(struct user_segment_descriptor)); 426 user_ldt_derefl(pldt); 427 } 428 ssdtosyssd(&sldt, &p->p_md.md_ldt_sd); 429 atomic_store_rel_ptr((volatile uintptr_t *)&mdp->md_ldt, 430 (uintptr_t)new_ldt); 431 if (p == curproc) 432 set_user_ldt(mdp); 433 434 return (mdp->md_ldt); 435 } 436 437 void 438 user_ldt_free(struct thread *td) 439 { 440 struct proc *p = td->td_proc; 441 struct mdproc *mdp = &p->p_md; 442 struct proc_ldt *pldt; 443 444 mtx_assert(&dt_lock, MA_OWNED); 445 if ((pldt = mdp->md_ldt) == NULL) { 446 mtx_unlock(&dt_lock); 447 return; 448 } 449 450 mdp->md_ldt = NULL; 451 bzero(&mdp->md_ldt_sd, sizeof(mdp->md_ldt_sd)); 452 if (td == curthread) 453 lldt(GSEL(GNULL_SEL, SEL_KPL)); 454 user_ldt_deref(pldt); 455 } 456 457 static void 458 user_ldt_derefl(struct proc_ldt *pldt) 459 { 460 461 if (--pldt->ldt_refcnt == 0) { 462 kmem_free(kernel_map, (vm_offset_t)pldt->ldt_base, 463 max_ldt_segment * sizeof(struct user_segment_descriptor)); 464 free(pldt, M_SUBPROC); 465 } 466 } 467 468 void 469 user_ldt_deref(struct proc_ldt *pldt) 470 { 471 472 mtx_assert(&dt_lock, MA_OWNED); 473 user_ldt_derefl(pldt); 474 mtx_unlock(&dt_lock); 475 } 476 477 /* 478 * Note for the authors of compat layers (linux, etc): copyout() in 479 * the function below is not a problem since it presents data in 480 * arch-specific format (i.e. i386-specific in this case), not in 481 * the OS-specific one. 482 */ 483 int 484 amd64_get_ldt(td, uap) 485 struct thread *td; 486 struct i386_ldt_args *uap; 487 { 488 int error = 0; 489 struct proc_ldt *pldt; 490 int num; 491 struct user_segment_descriptor *lp; 492 493 #ifdef DEBUG 494 printf("amd64_get_ldt: start=%d num=%d descs=%p\n", 495 uap->start, uap->num, (void *)uap->descs); 496 #endif 497 498 if ((pldt = td->td_proc->p_md.md_ldt) != NULL) { 499 lp = &((struct user_segment_descriptor *)(pldt->ldt_base)) 500 [uap->start]; 501 num = min(uap->num, max_ldt_segment); 502 } else 503 return (EINVAL); 504 505 if ((uap->start > (unsigned int)max_ldt_segment) || 506 ((unsigned int)num > (unsigned int)max_ldt_segment) || 507 ((unsigned int)(uap->start + num) > (unsigned int)max_ldt_segment)) 508 return(EINVAL); 509 510 error = copyout(lp, uap->descs, num * 511 sizeof(struct user_segment_descriptor)); 512 if (!error) 513 td->td_retval[0] = num; 514 515 return(error); 516 } 517 518 int 519 amd64_set_ldt(td, uap, descs) 520 struct thread *td; 521 struct i386_ldt_args *uap; 522 struct user_segment_descriptor *descs; 523 { 524 int error = 0, i; 525 int largest_ld; 526 struct mdproc *mdp = &td->td_proc->p_md; 527 struct proc_ldt *pldt; 528 struct user_segment_descriptor *dp; 529 struct proc *p; 530 531 #ifdef DEBUG 532 printf("amd64_set_ldt: start=%d num=%d descs=%p\n", 533 uap->start, uap->num, (void *)uap->descs); 534 #endif 535 536 td->td_pcb->pcb_full_iret = 1; 537 p = td->td_proc; 538 if (descs == NULL) { 539 /* Free descriptors */ 540 if (uap->start == 0 && uap->num == 0) 541 uap->num = max_ldt_segment; 542 if (uap->num <= 0) 543 return (EINVAL); 544 if ((pldt = mdp->md_ldt) == NULL || 545 uap->start >= max_ldt_segment) 546 return (0); 547 largest_ld = uap->start + uap->num; 548 if (largest_ld > max_ldt_segment) 549 largest_ld = max_ldt_segment; 550 i = largest_ld - uap->start; 551 mtx_lock(&dt_lock); 552 bzero(&((struct user_segment_descriptor *)(pldt->ldt_base)) 553 [uap->start], sizeof(struct user_segment_descriptor) * i); 554 mtx_unlock(&dt_lock); 555 return (0); 556 } 557 558 if (!(uap->start == LDT_AUTO_ALLOC && uap->num == 1)) { 559 /* verify range of descriptors to modify */ 560 largest_ld = uap->start + uap->num; 561 if (uap->start >= max_ldt_segment || 562 uap->num < 0 || largest_ld > max_ldt_segment) 563 return (EINVAL); 564 } 565 566 /* Check descriptors for access violations */ 567 for (i = 0; i < uap->num; i++) { 568 dp = &descs[i]; 569 570 switch (dp->sd_type) { 571 case SDT_SYSNULL: /* system null */ 572 dp->sd_p = 0; 573 break; 574 case SDT_SYS286TSS: 575 case SDT_SYSLDT: 576 case SDT_SYS286BSY: 577 case SDT_SYS286CGT: 578 case SDT_SYSTASKGT: 579 case SDT_SYS286IGT: 580 case SDT_SYS286TGT: 581 case SDT_SYSNULL2: 582 case SDT_SYSTSS: 583 case SDT_SYSNULL3: 584 case SDT_SYSBSY: 585 case SDT_SYSCGT: 586 case SDT_SYSNULL4: 587 case SDT_SYSIGT: 588 case SDT_SYSTGT: 589 /* I can't think of any reason to allow a user proc 590 * to create a segment of these types. They are 591 * for OS use only. 592 */ 593 return (EACCES); 594 /*NOTREACHED*/ 595 596 /* memory segment types */ 597 case SDT_MEMEC: /* memory execute only conforming */ 598 case SDT_MEMEAC: /* memory execute only accessed conforming */ 599 case SDT_MEMERC: /* memory execute read conforming */ 600 case SDT_MEMERAC: /* memory execute read accessed conforming */ 601 /* Must be "present" if executable and conforming. */ 602 if (dp->sd_p == 0) 603 return (EACCES); 604 break; 605 case SDT_MEMRO: /* memory read only */ 606 case SDT_MEMROA: /* memory read only accessed */ 607 case SDT_MEMRW: /* memory read write */ 608 case SDT_MEMRWA: /* memory read write accessed */ 609 case SDT_MEMROD: /* memory read only expand dwn limit */ 610 case SDT_MEMRODA: /* memory read only expand dwn lim accessed */ 611 case SDT_MEMRWD: /* memory read write expand dwn limit */ 612 case SDT_MEMRWDA: /* memory read write expand dwn lim acessed */ 613 case SDT_MEME: /* memory execute only */ 614 case SDT_MEMEA: /* memory execute only accessed */ 615 case SDT_MEMER: /* memory execute read */ 616 case SDT_MEMERA: /* memory execute read accessed */ 617 break; 618 default: 619 return(EINVAL); 620 /*NOTREACHED*/ 621 } 622 623 /* Only user (ring-3) descriptors may be present. */ 624 if ((dp->sd_p != 0) && (dp->sd_dpl != SEL_UPL)) 625 return (EACCES); 626 } 627 628 if (uap->start == LDT_AUTO_ALLOC && uap->num == 1) { 629 /* Allocate a free slot */ 630 mtx_lock(&dt_lock); 631 pldt = user_ldt_alloc(p, 0); 632 if (pldt == NULL) { 633 mtx_unlock(&dt_lock); 634 return (ENOMEM); 635 } 636 637 /* 638 * start scanning a bit up to leave room for NVidia and 639 * Wine, which still user the "Blat" method of allocation. 640 */ 641 i = 16; 642 dp = &((struct user_segment_descriptor *)(pldt->ldt_base))[i]; 643 for (; i < max_ldt_segment; ++i, ++dp) { 644 if (dp->sd_type == SDT_SYSNULL) 645 break; 646 } 647 if (i >= max_ldt_segment) { 648 mtx_unlock(&dt_lock); 649 return (ENOSPC); 650 } 651 uap->start = i; 652 error = amd64_set_ldt_data(td, i, 1, descs); 653 mtx_unlock(&dt_lock); 654 } else { 655 largest_ld = uap->start + uap->num; 656 if (largest_ld > max_ldt_segment) 657 return (EINVAL); 658 mtx_lock(&dt_lock); 659 if (user_ldt_alloc(p, 0) != NULL) { 660 error = amd64_set_ldt_data(td, uap->start, uap->num, 661 descs); 662 } 663 mtx_unlock(&dt_lock); 664 } 665 if (error == 0) 666 td->td_retval[0] = uap->start; 667 return (error); 668 } 669 670 int 671 amd64_set_ldt_data(struct thread *td, int start, int num, 672 struct user_segment_descriptor *descs) 673 { 674 struct mdproc *mdp = &td->td_proc->p_md; 675 struct proc_ldt *pldt = mdp->md_ldt; 676 677 mtx_assert(&dt_lock, MA_OWNED); 678 679 /* Fill in range */ 680 bcopy(descs, 681 &((struct user_segment_descriptor *)(pldt->ldt_base))[start], 682 num * sizeof(struct user_segment_descriptor)); 683 return (0); 684 }
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