Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
FreeBSD/Linux Kernel Cross Reference
sys/amd64/amd64/sys_machdep.c
Version:
- FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
SearchContext: - none - 3 - 10
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/11.1/sys/amd64/amd64/sys_machdep.c 330908 2018-03-14 04:00:00Z gordon $"); 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 pmap_pti_add_kva((vm_offset_t)tssp, (vm_offset_t)tssp + 362 ctob(IOPAGES + 1), false); 363 iomap = (char *)&tssp[1]; 364 memset(iomap, 0xff, IOPERM_BITMAP_SIZE); 365 critical_enter(); 366 /* Takes care of tss_rsp0. */ 367 memcpy(tssp, &common_tss[PCPU_GET(cpuid)], 368 sizeof(struct amd64tss)); 369 tssp->tss_iobase = sizeof(*tssp); 370 pcb->pcb_tssp = tssp; 371 tss_sd = PCPU_GET(tss); 372 tss_sd->sd_lobase = (u_long)tssp & 0xffffff; 373 tss_sd->sd_hibase = ((u_long)tssp >> 24) & 0xfffffffffful; 374 tss_sd->sd_type = SDT_SYSTSS; 375 ltr(GSEL(GPROC0_SEL, SEL_KPL)); 376 PCPU_SET(tssp, tssp); 377 critical_exit(); 378 } else 379 iomap = (char *)&pcb->pcb_tssp[1]; 380 for (i = uap->start; i < uap->start + uap->length; i++) { 381 if (uap->enable) 382 iomap[i >> 3] &= ~(1 << (i & 7)); 383 else 384 iomap[i >> 3] |= (1 << (i & 7)); 385 } 386 return (error); 387 } 388 389 int 390 amd64_get_ioperm(td, uap) 391 struct thread *td; 392 struct i386_ioperm_args *uap; 393 { 394 int i, state; 395 char *iomap; 396 397 if (uap->start >= IOPAGES * PAGE_SIZE * NBBY) 398 return (EINVAL); 399 if (td->td_pcb->pcb_tssp == NULL) { 400 uap->length = 0; 401 goto done; 402 } 403 404 iomap = (char *)&td->td_pcb->pcb_tssp[1]; 405 406 i = uap->start; 407 state = (iomap[i >> 3] >> (i & 7)) & 1; 408 uap->enable = !state; 409 uap->length = 1; 410 411 for (i = uap->start + 1; i < IOPAGES * PAGE_SIZE * NBBY; i++) { 412 if (state != ((iomap[i >> 3] >> (i & 7)) & 1)) 413 break; 414 uap->length++; 415 } 416 417 done: 418 return (0); 419 } 420 421 /* 422 * Update the GDT entry pointing to the LDT to point to the LDT of the 423 * current process. 424 */ 425 void 426 set_user_ldt(struct mdproc *mdp) 427 { 428 429 critical_enter(); 430 *PCPU_GET(ldt) = mdp->md_ldt_sd; 431 lldt(GSEL(GUSERLDT_SEL, SEL_KPL)); 432 critical_exit(); 433 } 434 435 #ifdef notyet 436 #ifdef SMP 437 static void 438 set_user_ldt_rv(struct vmspace *vmsp) 439 { 440 struct thread *td; 441 442 td = curthread; 443 if (vmsp != td->td_proc->p_vmspace) 444 return; 445 446 set_user_ldt(&td->td_proc->p_md); 447 } 448 #endif 449 #endif 450 451 struct proc_ldt * 452 user_ldt_alloc(struct proc *p, int force) 453 { 454 struct proc_ldt *pldt, *new_ldt; 455 struct mdproc *mdp; 456 struct soft_segment_descriptor sldt; 457 vm_offset_t sva; 458 vm_size_t sz; 459 460 mtx_assert(&dt_lock, MA_OWNED); 461 mdp = &p->p_md; 462 if (!force && mdp->md_ldt != NULL) 463 return (mdp->md_ldt); 464 mtx_unlock(&dt_lock); 465 new_ldt = malloc(sizeof(struct proc_ldt), M_SUBPROC, M_WAITOK); 466 sz = max_ldt_segment * sizeof(struct user_segment_descriptor); 467 sva = kmem_malloc(kernel_arena, sz, M_WAITOK | M_ZERO); 468 new_ldt->ldt_base = (caddr_t)sva; 469 pmap_pti_add_kva(sva, sva + sz, false); 470 new_ldt->ldt_refcnt = 1; 471 sldt.ssd_base = sva; 472 sldt.ssd_limit = sz - 1; 473 sldt.ssd_type = SDT_SYSLDT; 474 sldt.ssd_dpl = SEL_KPL; 475 sldt.ssd_p = 1; 476 sldt.ssd_long = 0; 477 sldt.ssd_def32 = 0; 478 sldt.ssd_gran = 0; 479 mtx_lock(&dt_lock); 480 pldt = mdp->md_ldt; 481 if (pldt != NULL && !force) { 482 pmap_pti_remove_kva(sva, sva + sz); 483 kmem_free(kernel_arena, sva, sz); 484 free(new_ldt, M_SUBPROC); 485 return (pldt); 486 } 487 488 if (pldt != NULL) { 489 bcopy(pldt->ldt_base, new_ldt->ldt_base, max_ldt_segment * 490 sizeof(struct user_segment_descriptor)); 491 user_ldt_derefl(pldt); 492 } 493 ssdtosyssd(&sldt, &p->p_md.md_ldt_sd); 494 atomic_store_rel_ptr((volatile uintptr_t *)&mdp->md_ldt, 495 (uintptr_t)new_ldt); 496 if (p == curproc) 497 set_user_ldt(mdp); 498 499 return (mdp->md_ldt); 500 } 501 502 void 503 user_ldt_free(struct thread *td) 504 { 505 struct proc *p = td->td_proc; 506 struct mdproc *mdp = &p->p_md; 507 struct proc_ldt *pldt; 508 509 mtx_assert(&dt_lock, MA_OWNED); 510 if ((pldt = mdp->md_ldt) == NULL) { 511 mtx_unlock(&dt_lock); 512 return; 513 } 514 515 mdp->md_ldt = NULL; 516 bzero(&mdp->md_ldt_sd, sizeof(mdp->md_ldt_sd)); 517 if (td == curthread) 518 lldt(GSEL(GNULL_SEL, SEL_KPL)); 519 user_ldt_deref(pldt); 520 } 521 522 static void 523 user_ldt_derefl(struct proc_ldt *pldt) 524 { 525 vm_offset_t sva; 526 vm_size_t sz; 527 528 if (--pldt->ldt_refcnt == 0) { 529 sva = (vm_offset_t)pldt->ldt_base; 530 sz = max_ldt_segment * sizeof(struct user_segment_descriptor); 531 pmap_pti_remove_kva(sva, sva + sz); 532 kmem_free(kernel_arena, sva, sz); 533 free(pldt, M_SUBPROC); 534 } 535 } 536 537 void 538 user_ldt_deref(struct proc_ldt *pldt) 539 { 540 541 mtx_assert(&dt_lock, MA_OWNED); 542 user_ldt_derefl(pldt); 543 mtx_unlock(&dt_lock); 544 } 545 546 /* 547 * Note for the authors of compat layers (linux, etc): copyout() in 548 * the function below is not a problem since it presents data in 549 * arch-specific format (i.e. i386-specific in this case), not in 550 * the OS-specific one. 551 */ 552 int 553 amd64_get_ldt(td, uap) 554 struct thread *td; 555 struct i386_ldt_args *uap; 556 { 557 int error = 0; 558 struct proc_ldt *pldt; 559 int num; 560 struct user_segment_descriptor *lp; 561 562 #ifdef DEBUG 563 printf("amd64_get_ldt: start=%d num=%d descs=%p\n", 564 uap->start, uap->num, (void *)uap->descs); 565 #endif 566 567 if ((pldt = td->td_proc->p_md.md_ldt) != NULL) { 568 lp = &((struct user_segment_descriptor *)(pldt->ldt_base)) 569 [uap->start]; 570 num = min(uap->num, max_ldt_segment); 571 } else 572 return (EINVAL); 573 574 if ((uap->start > (unsigned int)max_ldt_segment) || 575 ((unsigned int)num > (unsigned int)max_ldt_segment) || 576 ((unsigned int)(uap->start + num) > (unsigned int)max_ldt_segment)) 577 return(EINVAL); 578 579 error = copyout(lp, uap->descs, num * 580 sizeof(struct user_segment_descriptor)); 581 if (!error) 582 td->td_retval[0] = num; 583 584 return(error); 585 } 586 587 int 588 amd64_set_ldt(td, uap, descs) 589 struct thread *td; 590 struct i386_ldt_args *uap; 591 struct user_segment_descriptor *descs; 592 { 593 int error = 0; 594 unsigned int largest_ld, i; 595 struct mdproc *mdp = &td->td_proc->p_md; 596 struct proc_ldt *pldt; 597 struct user_segment_descriptor *dp; 598 struct proc *p; 599 600 #ifdef DEBUG 601 printf("amd64_set_ldt: start=%d num=%d descs=%p\n", 602 uap->start, uap->num, (void *)uap->descs); 603 #endif 604 605 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 606 p = td->td_proc; 607 if (descs == NULL) { 608 /* Free descriptors */ 609 if (uap->start == 0 && uap->num == 0) 610 uap->num = max_ldt_segment; 611 if (uap->num == 0) 612 return (EINVAL); 613 if ((pldt = mdp->md_ldt) == NULL || 614 uap->start >= max_ldt_segment) 615 return (0); 616 largest_ld = uap->start + uap->num; 617 if (largest_ld > max_ldt_segment) 618 largest_ld = max_ldt_segment; 619 if (largest_ld < uap->start) 620 return (EINVAL); 621 i = largest_ld - uap->start; 622 mtx_lock(&dt_lock); 623 bzero(&((struct user_segment_descriptor *)(pldt->ldt_base)) 624 [uap->start], sizeof(struct user_segment_descriptor) * i); 625 mtx_unlock(&dt_lock); 626 return (0); 627 } 628 629 if (!(uap->start == LDT_AUTO_ALLOC && uap->num == 1)) { 630 /* verify range of descriptors to modify */ 631 largest_ld = uap->start + uap->num; 632 if (uap->start >= max_ldt_segment || 633 largest_ld > max_ldt_segment || 634 largest_ld < uap->start) 635 return (EINVAL); 636 } 637 638 /* Check descriptors for access violations */ 639 for (i = 0; i < uap->num; i++) { 640 dp = &descs[i]; 641 642 switch (dp->sd_type) { 643 case SDT_SYSNULL: /* system null */ 644 dp->sd_p = 0; 645 break; 646 case SDT_SYS286TSS: 647 case SDT_SYSLDT: 648 case SDT_SYS286BSY: 649 case SDT_SYS286CGT: 650 case SDT_SYSTASKGT: 651 case SDT_SYS286IGT: 652 case SDT_SYS286TGT: 653 case SDT_SYSNULL2: 654 case SDT_SYSTSS: 655 case SDT_SYSNULL3: 656 case SDT_SYSBSY: 657 case SDT_SYSCGT: 658 case SDT_SYSNULL4: 659 case SDT_SYSIGT: 660 case SDT_SYSTGT: 661 /* I can't think of any reason to allow a user proc 662 * to create a segment of these types. They are 663 * for OS use only. 664 */ 665 return (EACCES); 666 /*NOTREACHED*/ 667 668 /* memory segment types */ 669 case SDT_MEMEC: /* memory execute only conforming */ 670 case SDT_MEMEAC: /* memory execute only accessed conforming */ 671 case SDT_MEMERC: /* memory execute read conforming */ 672 case SDT_MEMERAC: /* memory execute read accessed conforming */ 673 /* Must be "present" if executable and conforming. */ 674 if (dp->sd_p == 0) 675 return (EACCES); 676 break; 677 case SDT_MEMRO: /* memory read only */ 678 case SDT_MEMROA: /* memory read only accessed */ 679 case SDT_MEMRW: /* memory read write */ 680 case SDT_MEMRWA: /* memory read write accessed */ 681 case SDT_MEMROD: /* memory read only expand dwn limit */ 682 case SDT_MEMRODA: /* memory read only expand dwn lim accessed */ 683 case SDT_MEMRWD: /* memory read write expand dwn limit */ 684 case SDT_MEMRWDA: /* memory read write expand dwn lim acessed */ 685 case SDT_MEME: /* memory execute only */ 686 case SDT_MEMEA: /* memory execute only accessed */ 687 case SDT_MEMER: /* memory execute read */ 688 case SDT_MEMERA: /* memory execute read accessed */ 689 break; 690 default: 691 return(EINVAL); 692 /*NOTREACHED*/ 693 } 694 695 /* Only user (ring-3) descriptors may be present. */ 696 if ((dp->sd_p != 0) && (dp->sd_dpl != SEL_UPL)) 697 return (EACCES); 698 } 699 700 if (uap->start == LDT_AUTO_ALLOC && uap->num == 1) { 701 /* Allocate a free slot */ 702 mtx_lock(&dt_lock); 703 pldt = user_ldt_alloc(p, 0); 704 if (pldt == NULL) { 705 mtx_unlock(&dt_lock); 706 return (ENOMEM); 707 } 708 709 /* 710 * start scanning a bit up to leave room for NVidia and 711 * Wine, which still user the "Blat" method of allocation. 712 */ 713 i = 16; 714 dp = &((struct user_segment_descriptor *)(pldt->ldt_base))[i]; 715 for (; i < max_ldt_segment; ++i, ++dp) { 716 if (dp->sd_type == SDT_SYSNULL) 717 break; 718 } 719 if (i >= max_ldt_segment) { 720 mtx_unlock(&dt_lock); 721 return (ENOSPC); 722 } 723 uap->start = i; 724 error = amd64_set_ldt_data(td, i, 1, descs); 725 mtx_unlock(&dt_lock); 726 } else { 727 largest_ld = uap->start + uap->num; 728 if (largest_ld > max_ldt_segment) 729 return (EINVAL); 730 mtx_lock(&dt_lock); 731 if (user_ldt_alloc(p, 0) != NULL) { 732 error = amd64_set_ldt_data(td, uap->start, uap->num, 733 descs); 734 } 735 mtx_unlock(&dt_lock); 736 } 737 if (error == 0) 738 td->td_retval[0] = uap->start; 739 return (error); 740 } 741 742 int 743 amd64_set_ldt_data(struct thread *td, int start, int num, 744 struct user_segment_descriptor *descs) 745 { 746 struct mdproc *mdp = &td->td_proc->p_md; 747 struct proc_ldt *pldt = mdp->md_ldt; 748 749 mtx_assert(&dt_lock, MA_OWNED); 750 751 /* Fill in range */ 752 bcopy(descs, 753 &((struct user_segment_descriptor *)(pldt->ldt_base))[start], 754 num * sizeof(struct user_segment_descriptor)); 755 return (0); 756 }
Cache object: aba1c84a64f03bf1e8617f2e34c1e268
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]