Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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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 * 3. 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/11.0/sys/amd64/amd64/sys_machdep.c 307935 2016-10-25 17:11:20Z glebius $"); 35 36 #include "opt_capsicum.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/capsicum.h> 41 #include <sys/kernel.h> 42 #include <sys/lock.h> 43 #include <sys/malloc.h> 44 #include <sys/mutex.h> 45 #include <sys/priv.h> 46 #include <sys/proc.h> 47 #include <sys/sysproto.h> 48 #include <sys/uio.h> 49 50 #include <vm/vm.h> 51 #include <vm/pmap.h> 52 #include <vm/vm_kern.h> /* for kernel_map */ 53 #include <vm/vm_extern.h> 54 55 #include <machine/frame.h> 56 #include <machine/md_var.h> 57 #include <machine/pcb.h> 58 #include <machine/specialreg.h> 59 #include <machine/sysarch.h> 60 #include <machine/tss.h> 61 #include <machine/vmparam.h> 62 63 #include <security/audit/audit.h> 64 65 #define MAX_LD 8192 66 67 int max_ldt_segment = 1024; 68 SYSCTL_INT(_machdep, OID_AUTO, max_ldt_segment, CTLFLAG_RDTUN, 69 &max_ldt_segment, 0, 70 "Maximum number of allowed LDT segments in the single address space"); 71 72 static void 73 max_ldt_segment_init(void *arg __unused) 74 { 75 76 if (max_ldt_segment <= 0) 77 max_ldt_segment = 1; 78 if (max_ldt_segment > MAX_LD) 79 max_ldt_segment = MAX_LD; 80 } 81 SYSINIT(maxldt, SI_SUB_VM_CONF, SI_ORDER_ANY, max_ldt_segment_init, NULL); 82 83 #ifdef notyet 84 #ifdef SMP 85 static void set_user_ldt_rv(struct vmspace *vmsp); 86 #endif 87 #endif 88 static void user_ldt_derefl(struct proc_ldt *pldt); 89 90 #ifndef _SYS_SYSPROTO_H_ 91 struct sysarch_args { 92 int op; 93 char *parms; 94 }; 95 #endif 96 97 int 98 sysarch_ldt(struct thread *td, struct sysarch_args *uap, int uap_space) 99 { 100 struct i386_ldt_args *largs, la; 101 struct user_segment_descriptor *lp; 102 int error = 0; 103 104 /* 105 * XXXKIB check that the BSM generation code knows to encode 106 * the op argument. 107 */ 108 AUDIT_ARG_CMD(uap->op); 109 if (uap_space == UIO_USERSPACE) { 110 error = copyin(uap->parms, &la, sizeof(struct i386_ldt_args)); 111 if (error != 0) 112 return (error); 113 largs = &la; 114 } else 115 largs = (struct i386_ldt_args *)uap->parms; 116 117 switch (uap->op) { 118 case I386_GET_LDT: 119 error = amd64_get_ldt(td, largs); 120 break; 121 case I386_SET_LDT: 122 if (largs->descs != NULL && largs->num > max_ldt_segment) 123 return (EINVAL); 124 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 125 if (largs->descs != NULL) { 126 lp = malloc(largs->num * sizeof(struct 127 user_segment_descriptor), M_TEMP, M_WAITOK); 128 error = copyin(largs->descs, lp, largs->num * 129 sizeof(struct user_segment_descriptor)); 130 if (error == 0) 131 error = amd64_set_ldt(td, largs, lp); 132 free(lp, M_TEMP); 133 } else { 134 error = amd64_set_ldt(td, largs, NULL); 135 } 136 break; 137 } 138 return (error); 139 } 140 141 void 142 update_gdt_gsbase(struct thread *td, uint32_t base) 143 { 144 struct user_segment_descriptor *sd; 145 146 if (td != curthread) 147 return; 148 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 149 critical_enter(); 150 sd = PCPU_GET(gs32p); 151 sd->sd_lobase = base & 0xffffff; 152 sd->sd_hibase = (base >> 24) & 0xff; 153 critical_exit(); 154 } 155 156 void 157 update_gdt_fsbase(struct thread *td, uint32_t base) 158 { 159 struct user_segment_descriptor *sd; 160 161 if (td != curthread) 162 return; 163 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 164 critical_enter(); 165 sd = PCPU_GET(fs32p); 166 sd->sd_lobase = base & 0xffffff; 167 sd->sd_hibase = (base >> 24) & 0xff; 168 critical_exit(); 169 } 170 171 int 172 sysarch(td, uap) 173 struct thread *td; 174 register struct sysarch_args *uap; 175 { 176 int error = 0; 177 struct pcb *pcb = curthread->td_pcb; 178 uint32_t i386base; 179 uint64_t a64base; 180 struct i386_ioperm_args iargs; 181 struct i386_get_xfpustate i386xfpu; 182 struct amd64_get_xfpustate a64xfpu; 183 184 #ifdef CAPABILITY_MODE 185 /* 186 * When adding new operations, add a new case statement here to 187 * explicitly indicate whether or not the operation is safe to 188 * perform in capability mode. 189 */ 190 if (IN_CAPABILITY_MODE(td)) { 191 switch (uap->op) { 192 case I386_GET_LDT: 193 case I386_SET_LDT: 194 case I386_GET_IOPERM: 195 case I386_GET_FSBASE: 196 case I386_SET_FSBASE: 197 case I386_GET_GSBASE: 198 case I386_SET_GSBASE: 199 case I386_GET_XFPUSTATE: 200 case AMD64_GET_FSBASE: 201 case AMD64_SET_FSBASE: 202 case AMD64_GET_GSBASE: 203 case AMD64_SET_GSBASE: 204 case AMD64_GET_XFPUSTATE: 205 break; 206 207 case I386_SET_IOPERM: 208 default: 209 #ifdef KTRACE 210 if (KTRPOINT(td, KTR_CAPFAIL)) 211 ktrcapfail(CAPFAIL_SYSCALL, NULL, NULL); 212 #endif 213 return (ECAPMODE); 214 } 215 } 216 #endif 217 218 if (uap->op == I386_GET_LDT || uap->op == I386_SET_LDT) 219 return (sysarch_ldt(td, uap, UIO_USERSPACE)); 220 /* 221 * XXXKIB check that the BSM generation code knows to encode 222 * the op argument. 223 */ 224 AUDIT_ARG_CMD(uap->op); 225 switch (uap->op) { 226 case I386_GET_IOPERM: 227 case I386_SET_IOPERM: 228 if ((error = copyin(uap->parms, &iargs, 229 sizeof(struct i386_ioperm_args))) != 0) 230 return (error); 231 break; 232 case I386_GET_XFPUSTATE: 233 if ((error = copyin(uap->parms, &i386xfpu, 234 sizeof(struct i386_get_xfpustate))) != 0) 235 return (error); 236 a64xfpu.addr = (void *)(uintptr_t)i386xfpu.addr; 237 a64xfpu.len = i386xfpu.len; 238 break; 239 case AMD64_GET_XFPUSTATE: 240 if ((error = copyin(uap->parms, &a64xfpu, 241 sizeof(struct amd64_get_xfpustate))) != 0) 242 return (error); 243 break; 244 default: 245 break; 246 } 247 248 switch (uap->op) { 249 case I386_GET_IOPERM: 250 error = amd64_get_ioperm(td, &iargs); 251 if (error == 0) 252 error = copyout(&iargs, uap->parms, 253 sizeof(struct i386_ioperm_args)); 254 break; 255 case I386_SET_IOPERM: 256 error = amd64_set_ioperm(td, &iargs); 257 break; 258 case I386_GET_FSBASE: 259 i386base = pcb->pcb_fsbase; 260 error = copyout(&i386base, uap->parms, sizeof(i386base)); 261 break; 262 case I386_SET_FSBASE: 263 error = copyin(uap->parms, &i386base, sizeof(i386base)); 264 if (!error) { 265 pcb->pcb_fsbase = i386base; 266 td->td_frame->tf_fs = _ufssel; 267 update_gdt_fsbase(td, i386base); 268 } 269 break; 270 case I386_GET_GSBASE: 271 i386base = pcb->pcb_gsbase; 272 error = copyout(&i386base, uap->parms, sizeof(i386base)); 273 break; 274 case I386_SET_GSBASE: 275 error = copyin(uap->parms, &i386base, sizeof(i386base)); 276 if (!error) { 277 pcb->pcb_gsbase = i386base; 278 td->td_frame->tf_gs = _ugssel; 279 update_gdt_gsbase(td, i386base); 280 } 281 break; 282 case AMD64_GET_FSBASE: 283 error = copyout(&pcb->pcb_fsbase, uap->parms, sizeof(pcb->pcb_fsbase)); 284 break; 285 286 case AMD64_SET_FSBASE: 287 error = copyin(uap->parms, &a64base, sizeof(a64base)); 288 if (!error) { 289 if (a64base < VM_MAXUSER_ADDRESS) { 290 pcb->pcb_fsbase = a64base; 291 set_pcb_flags(pcb, PCB_FULL_IRET); 292 td->td_frame->tf_fs = _ufssel; 293 } else 294 error = EINVAL; 295 } 296 break; 297 298 case AMD64_GET_GSBASE: 299 error = copyout(&pcb->pcb_gsbase, uap->parms, sizeof(pcb->pcb_gsbase)); 300 break; 301 302 case AMD64_SET_GSBASE: 303 error = copyin(uap->parms, &a64base, sizeof(a64base)); 304 if (!error) { 305 if (a64base < VM_MAXUSER_ADDRESS) { 306 pcb->pcb_gsbase = a64base; 307 set_pcb_flags(pcb, PCB_FULL_IRET); 308 td->td_frame->tf_gs = _ugssel; 309 } else 310 error = EINVAL; 311 } 312 break; 313 314 case I386_GET_XFPUSTATE: 315 case AMD64_GET_XFPUSTATE: 316 if (a64xfpu.len > cpu_max_ext_state_size - 317 sizeof(struct savefpu)) 318 return (EINVAL); 319 fpugetregs(td); 320 error = copyout((char *)(get_pcb_user_save_td(td) + 1), 321 a64xfpu.addr, a64xfpu.len); 322 break; 323 324 default: 325 error = EINVAL; 326 break; 327 } 328 return (error); 329 } 330 331 int 332 amd64_set_ioperm(td, uap) 333 struct thread *td; 334 struct i386_ioperm_args *uap; 335 { 336 char *iomap; 337 struct amd64tss *tssp; 338 struct system_segment_descriptor *tss_sd; 339 struct pcb *pcb; 340 u_int i; 341 int error; 342 343 if ((error = priv_check(td, PRIV_IO)) != 0) 344 return (error); 345 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 346 return (error); 347 if (uap->start > uap->start + uap->length || 348 uap->start + uap->length > IOPAGES * PAGE_SIZE * NBBY) 349 return (EINVAL); 350 351 /* 352 * XXX 353 * While this is restricted to root, we should probably figure out 354 * whether any other driver is using this i/o address, as so not to 355 * cause confusion. This probably requires a global 'usage registry'. 356 */ 357 pcb = td->td_pcb; 358 if (pcb->pcb_tssp == NULL) { 359 tssp = (struct amd64tss *)kmem_malloc(kernel_arena, 360 ctob(IOPAGES+1), M_WAITOK); 361 iomap = (char *)&tssp[1]; 362 memset(iomap, 0xff, IOPERM_BITMAP_SIZE); 363 critical_enter(); 364 /* Takes care of tss_rsp0. */ 365 memcpy(tssp, &common_tss[PCPU_GET(cpuid)], 366 sizeof(struct amd64tss)); 367 tssp->tss_iobase = sizeof(*tssp); 368 pcb->pcb_tssp = tssp; 369 tss_sd = PCPU_GET(tss); 370 tss_sd->sd_lobase = (u_long)tssp & 0xffffff; 371 tss_sd->sd_hibase = ((u_long)tssp >> 24) & 0xfffffffffful; 372 tss_sd->sd_type = SDT_SYSTSS; 373 ltr(GSEL(GPROC0_SEL, SEL_KPL)); 374 PCPU_SET(tssp, tssp); 375 critical_exit(); 376 } else 377 iomap = (char *)&pcb->pcb_tssp[1]; 378 for (i = uap->start; i < uap->start + uap->length; i++) { 379 if (uap->enable) 380 iomap[i >> 3] &= ~(1 << (i & 7)); 381 else 382 iomap[i >> 3] |= (1 << (i & 7)); 383 } 384 return (error); 385 } 386 387 int 388 amd64_get_ioperm(td, uap) 389 struct thread *td; 390 struct i386_ioperm_args *uap; 391 { 392 int i, state; 393 char *iomap; 394 395 if (uap->start >= IOPAGES * PAGE_SIZE * NBBY) 396 return (EINVAL); 397 if (td->td_pcb->pcb_tssp == NULL) { 398 uap->length = 0; 399 goto done; 400 } 401 402 iomap = (char *)&td->td_pcb->pcb_tssp[1]; 403 404 i = uap->start; 405 state = (iomap[i >> 3] >> (i & 7)) & 1; 406 uap->enable = !state; 407 uap->length = 1; 408 409 for (i = uap->start + 1; i < IOPAGES * PAGE_SIZE * NBBY; i++) { 410 if (state != ((iomap[i >> 3] >> (i & 7)) & 1)) 411 break; 412 uap->length++; 413 } 414 415 done: 416 return (0); 417 } 418 419 /* 420 * Update the GDT entry pointing to the LDT to point to the LDT of the 421 * current process. 422 */ 423 void 424 set_user_ldt(struct mdproc *mdp) 425 { 426 427 critical_enter(); 428 *PCPU_GET(ldt) = mdp->md_ldt_sd; 429 lldt(GSEL(GUSERLDT_SEL, SEL_KPL)); 430 critical_exit(); 431 } 432 433 #ifdef notyet 434 #ifdef SMP 435 static void 436 set_user_ldt_rv(struct vmspace *vmsp) 437 { 438 struct thread *td; 439 440 td = curthread; 441 if (vmsp != td->td_proc->p_vmspace) 442 return; 443 444 set_user_ldt(&td->td_proc->p_md); 445 } 446 #endif 447 #endif 448 449 struct proc_ldt * 450 user_ldt_alloc(struct proc *p, int force) 451 { 452 struct proc_ldt *pldt, *new_ldt; 453 struct mdproc *mdp; 454 struct soft_segment_descriptor sldt; 455 456 mtx_assert(&dt_lock, MA_OWNED); 457 mdp = &p->p_md; 458 if (!force && mdp->md_ldt != NULL) 459 return (mdp->md_ldt); 460 mtx_unlock(&dt_lock); 461 new_ldt = malloc(sizeof(struct proc_ldt), M_SUBPROC, M_WAITOK); 462 new_ldt->ldt_base = (caddr_t)kmem_malloc(kernel_arena, 463 max_ldt_segment * sizeof(struct user_segment_descriptor), 464 M_WAITOK | M_ZERO); 465 new_ldt->ldt_refcnt = 1; 466 sldt.ssd_base = (uint64_t)new_ldt->ldt_base; 467 sldt.ssd_limit = max_ldt_segment * 468 sizeof(struct user_segment_descriptor) - 1; 469 sldt.ssd_type = SDT_SYSLDT; 470 sldt.ssd_dpl = SEL_KPL; 471 sldt.ssd_p = 1; 472 sldt.ssd_long = 0; 473 sldt.ssd_def32 = 0; 474 sldt.ssd_gran = 0; 475 mtx_lock(&dt_lock); 476 pldt = mdp->md_ldt; 477 if (pldt != NULL && !force) { 478 kmem_free(kernel_arena, (vm_offset_t)new_ldt->ldt_base, 479 max_ldt_segment * sizeof(struct user_segment_descriptor)); 480 free(new_ldt, M_SUBPROC); 481 return (pldt); 482 } 483 484 if (pldt != NULL) { 485 bcopy(pldt->ldt_base, new_ldt->ldt_base, max_ldt_segment * 486 sizeof(struct user_segment_descriptor)); 487 user_ldt_derefl(pldt); 488 } 489 ssdtosyssd(&sldt, &p->p_md.md_ldt_sd); 490 atomic_store_rel_ptr((volatile uintptr_t *)&mdp->md_ldt, 491 (uintptr_t)new_ldt); 492 if (p == curproc) 493 set_user_ldt(mdp); 494 495 return (mdp->md_ldt); 496 } 497 498 void 499 user_ldt_free(struct thread *td) 500 { 501 struct proc *p = td->td_proc; 502 struct mdproc *mdp = &p->p_md; 503 struct proc_ldt *pldt; 504 505 mtx_assert(&dt_lock, MA_OWNED); 506 if ((pldt = mdp->md_ldt) == NULL) { 507 mtx_unlock(&dt_lock); 508 return; 509 } 510 511 mdp->md_ldt = NULL; 512 bzero(&mdp->md_ldt_sd, sizeof(mdp->md_ldt_sd)); 513 if (td == curthread) 514 lldt(GSEL(GNULL_SEL, SEL_KPL)); 515 user_ldt_deref(pldt); 516 } 517 518 static void 519 user_ldt_derefl(struct proc_ldt *pldt) 520 { 521 522 if (--pldt->ldt_refcnt == 0) { 523 kmem_free(kernel_arena, (vm_offset_t)pldt->ldt_base, 524 max_ldt_segment * sizeof(struct user_segment_descriptor)); 525 free(pldt, M_SUBPROC); 526 } 527 } 528 529 void 530 user_ldt_deref(struct proc_ldt *pldt) 531 { 532 533 mtx_assert(&dt_lock, MA_OWNED); 534 user_ldt_derefl(pldt); 535 mtx_unlock(&dt_lock); 536 } 537 538 /* 539 * Note for the authors of compat layers (linux, etc): copyout() in 540 * the function below is not a problem since it presents data in 541 * arch-specific format (i.e. i386-specific in this case), not in 542 * the OS-specific one. 543 */ 544 int 545 amd64_get_ldt(td, uap) 546 struct thread *td; 547 struct i386_ldt_args *uap; 548 { 549 int error = 0; 550 struct proc_ldt *pldt; 551 int num; 552 struct user_segment_descriptor *lp; 553 554 #ifdef DEBUG 555 printf("amd64_get_ldt: start=%d num=%d descs=%p\n", 556 uap->start, uap->num, (void *)uap->descs); 557 #endif 558 559 if ((pldt = td->td_proc->p_md.md_ldt) != NULL) { 560 lp = &((struct user_segment_descriptor *)(pldt->ldt_base)) 561 [uap->start]; 562 num = min(uap->num, max_ldt_segment); 563 } else 564 return (EINVAL); 565 566 if ((uap->start > (unsigned int)max_ldt_segment) || 567 ((unsigned int)num > (unsigned int)max_ldt_segment) || 568 ((unsigned int)(uap->start + num) > (unsigned int)max_ldt_segment)) 569 return(EINVAL); 570 571 error = copyout(lp, uap->descs, num * 572 sizeof(struct user_segment_descriptor)); 573 if (!error) 574 td->td_retval[0] = num; 575 576 return(error); 577 } 578 579 int 580 amd64_set_ldt(td, uap, descs) 581 struct thread *td; 582 struct i386_ldt_args *uap; 583 struct user_segment_descriptor *descs; 584 { 585 int error = 0; 586 unsigned int largest_ld, i; 587 struct mdproc *mdp = &td->td_proc->p_md; 588 struct proc_ldt *pldt; 589 struct user_segment_descriptor *dp; 590 struct proc *p; 591 592 #ifdef DEBUG 593 printf("amd64_set_ldt: start=%d num=%d descs=%p\n", 594 uap->start, uap->num, (void *)uap->descs); 595 #endif 596 597 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 598 p = td->td_proc; 599 if (descs == NULL) { 600 /* Free descriptors */ 601 if (uap->start == 0 && uap->num == 0) 602 uap->num = max_ldt_segment; 603 if (uap->num == 0) 604 return (EINVAL); 605 if ((pldt = mdp->md_ldt) == NULL || 606 uap->start >= max_ldt_segment) 607 return (0); 608 largest_ld = uap->start + uap->num; 609 if (largest_ld > max_ldt_segment) 610 largest_ld = max_ldt_segment; 611 if (largest_ld < uap->start) 612 return (EINVAL); 613 i = largest_ld - uap->start; 614 mtx_lock(&dt_lock); 615 bzero(&((struct user_segment_descriptor *)(pldt->ldt_base)) 616 [uap->start], sizeof(struct user_segment_descriptor) * i); 617 mtx_unlock(&dt_lock); 618 return (0); 619 } 620 621 if (!(uap->start == LDT_AUTO_ALLOC && uap->num == 1)) { 622 /* verify range of descriptors to modify */ 623 largest_ld = uap->start + uap->num; 624 if (uap->start >= max_ldt_segment || 625 largest_ld > max_ldt_segment || 626 largest_ld < uap->start) 627 return (EINVAL); 628 } 629 630 /* Check descriptors for access violations */ 631 for (i = 0; i < uap->num; i++) { 632 dp = &descs[i]; 633 634 switch (dp->sd_type) { 635 case SDT_SYSNULL: /* system null */ 636 dp->sd_p = 0; 637 break; 638 case SDT_SYS286TSS: 639 case SDT_SYSLDT: 640 case SDT_SYS286BSY: 641 case SDT_SYS286CGT: 642 case SDT_SYSTASKGT: 643 case SDT_SYS286IGT: 644 case SDT_SYS286TGT: 645 case SDT_SYSNULL2: 646 case SDT_SYSTSS: 647 case SDT_SYSNULL3: 648 case SDT_SYSBSY: 649 case SDT_SYSCGT: 650 case SDT_SYSNULL4: 651 case SDT_SYSIGT: 652 case SDT_SYSTGT: 653 /* I can't think of any reason to allow a user proc 654 * to create a segment of these types. They are 655 * for OS use only. 656 */ 657 return (EACCES); 658 /*NOTREACHED*/ 659 660 /* memory segment types */ 661 case SDT_MEMEC: /* memory execute only conforming */ 662 case SDT_MEMEAC: /* memory execute only accessed conforming */ 663 case SDT_MEMERC: /* memory execute read conforming */ 664 case SDT_MEMERAC: /* memory execute read accessed conforming */ 665 /* Must be "present" if executable and conforming. */ 666 if (dp->sd_p == 0) 667 return (EACCES); 668 break; 669 case SDT_MEMRO: /* memory read only */ 670 case SDT_MEMROA: /* memory read only accessed */ 671 case SDT_MEMRW: /* memory read write */ 672 case SDT_MEMRWA: /* memory read write accessed */ 673 case SDT_MEMROD: /* memory read only expand dwn limit */ 674 case SDT_MEMRODA: /* memory read only expand dwn lim accessed */ 675 case SDT_MEMRWD: /* memory read write expand dwn limit */ 676 case SDT_MEMRWDA: /* memory read write expand dwn lim acessed */ 677 case SDT_MEME: /* memory execute only */ 678 case SDT_MEMEA: /* memory execute only accessed */ 679 case SDT_MEMER: /* memory execute read */ 680 case SDT_MEMERA: /* memory execute read accessed */ 681 break; 682 default: 683 return(EINVAL); 684 /*NOTREACHED*/ 685 } 686 687 /* Only user (ring-3) descriptors may be present. */ 688 if ((dp->sd_p != 0) && (dp->sd_dpl != SEL_UPL)) 689 return (EACCES); 690 } 691 692 if (uap->start == LDT_AUTO_ALLOC && uap->num == 1) { 693 /* Allocate a free slot */ 694 mtx_lock(&dt_lock); 695 pldt = user_ldt_alloc(p, 0); 696 if (pldt == NULL) { 697 mtx_unlock(&dt_lock); 698 return (ENOMEM); 699 } 700 701 /* 702 * start scanning a bit up to leave room for NVidia and 703 * Wine, which still user the "Blat" method of allocation. 704 */ 705 i = 16; 706 dp = &((struct user_segment_descriptor *)(pldt->ldt_base))[i]; 707 for (; i < max_ldt_segment; ++i, ++dp) { 708 if (dp->sd_type == SDT_SYSNULL) 709 break; 710 } 711 if (i >= max_ldt_segment) { 712 mtx_unlock(&dt_lock); 713 return (ENOSPC); 714 } 715 uap->start = i; 716 error = amd64_set_ldt_data(td, i, 1, descs); 717 mtx_unlock(&dt_lock); 718 } else { 719 largest_ld = uap->start + uap->num; 720 if (largest_ld > max_ldt_segment) 721 return (EINVAL); 722 mtx_lock(&dt_lock); 723 if (user_ldt_alloc(p, 0) != NULL) { 724 error = amd64_set_ldt_data(td, uap->start, uap->num, 725 descs); 726 } 727 mtx_unlock(&dt_lock); 728 } 729 if (error == 0) 730 td->td_retval[0] = uap->start; 731 return (error); 732 } 733 734 int 735 amd64_set_ldt_data(struct thread *td, int start, int num, 736 struct user_segment_descriptor *descs) 737 { 738 struct mdproc *mdp = &td->td_proc->p_md; 739 struct proc_ldt *pldt = mdp->md_ldt; 740 741 mtx_assert(&dt_lock, MA_OWNED); 742 743 /* Fill in range */ 744 bcopy(descs, 745 &((struct user_segment_descriptor *)(pldt->ldt_base))[start], 746 num * sizeof(struct user_segment_descriptor)); 747 return (0); 748 }
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