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 * 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/9.1/sys/amd64/amd64/sys_machdep.c 231979 2012-02-21 20:56:03Z kib $"); 35 36 #include "opt_capsicum.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/capability.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 TUNABLE_INT_FETCH("machdep.max_ldt_segment", &max_ldt_segment); 77 if (max_ldt_segment <= 0) 78 max_ldt_segment = 1; 79 if (max_ldt_segment > MAX_LD) 80 max_ldt_segment = MAX_LD; 81 } 82 SYSINIT(maxldt, SI_SUB_VM_CONF, SI_ORDER_ANY, max_ldt_segment_init, NULL); 83 84 #ifdef notyet 85 #ifdef SMP 86 static void set_user_ldt_rv(struct vmspace *vmsp); 87 #endif 88 #endif 89 static void user_ldt_derefl(struct proc_ldt *pldt); 90 91 #ifndef _SYS_SYSPROTO_H_ 92 struct sysarch_args { 93 int op; 94 char *parms; 95 }; 96 #endif 97 98 int 99 sysarch_ldt(struct thread *td, struct sysarch_args *uap, int uap_space) 100 { 101 struct i386_ldt_args *largs, la; 102 struct user_segment_descriptor *lp; 103 int error = 0; 104 105 /* 106 * XXXKIB check that the BSM generation code knows to encode 107 * the op argument. 108 */ 109 AUDIT_ARG_CMD(uap->op); 110 if (uap_space == UIO_USERSPACE) { 111 error = copyin(uap->parms, &la, sizeof(struct i386_ldt_args)); 112 if (error != 0) 113 return (error); 114 largs = &la; 115 } else 116 largs = (struct i386_ldt_args *)uap->parms; 117 118 switch (uap->op) { 119 case I386_GET_LDT: 120 error = amd64_get_ldt(td, largs); 121 break; 122 case I386_SET_LDT: 123 if (largs->descs != NULL && largs->num > max_ldt_segment) 124 return (EINVAL); 125 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 126 if (largs->descs != NULL) { 127 lp = malloc(largs->num * sizeof(struct 128 user_segment_descriptor), M_TEMP, M_WAITOK); 129 error = copyin(largs->descs, lp, largs->num * 130 sizeof(struct user_segment_descriptor)); 131 if (error == 0) 132 error = amd64_set_ldt(td, largs, lp); 133 free(lp, M_TEMP); 134 } else { 135 error = amd64_set_ldt(td, largs, NULL); 136 } 137 break; 138 } 139 return (error); 140 } 141 142 void 143 update_gdt_gsbase(struct thread *td, uint32_t base) 144 { 145 struct user_segment_descriptor *sd; 146 147 if (td != curthread) 148 return; 149 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 150 critical_enter(); 151 sd = PCPU_GET(gs32p); 152 sd->sd_lobase = base & 0xffffff; 153 sd->sd_hibase = (base >> 24) & 0xff; 154 critical_exit(); 155 } 156 157 void 158 update_gdt_fsbase(struct thread *td, uint32_t base) 159 { 160 struct user_segment_descriptor *sd; 161 162 if (td != curthread) 163 return; 164 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 165 critical_enter(); 166 sd = PCPU_GET(fs32p); 167 sd->sd_lobase = base & 0xffffff; 168 sd->sd_hibase = (base >> 24) & 0xff; 169 critical_exit(); 170 } 171 172 int 173 sysarch(td, uap) 174 struct thread *td; 175 register struct sysarch_args *uap; 176 { 177 int error = 0; 178 struct pcb *pcb = curthread->td_pcb; 179 uint32_t i386base; 180 uint64_t a64base; 181 struct i386_ioperm_args iargs; 182 struct i386_get_xfpustate i386xfpu; 183 struct amd64_get_xfpustate a64xfpu; 184 185 #ifdef CAPABILITY_MODE 186 /* 187 * When adding new operations, add a new case statement here to 188 * explicitly indicate whether or not the operation is safe to 189 * perform in capability mode. 190 */ 191 if (IN_CAPABILITY_MODE(td)) { 192 switch (uap->op) { 193 case I386_GET_LDT: 194 case I386_SET_LDT: 195 case I386_GET_IOPERM: 196 case I386_GET_FSBASE: 197 case I386_SET_FSBASE: 198 case I386_GET_GSBASE: 199 case I386_SET_GSBASE: 200 case I386_GET_XFPUSTATE: 201 case AMD64_GET_FSBASE: 202 case AMD64_SET_FSBASE: 203 case AMD64_GET_GSBASE: 204 case AMD64_SET_GSBASE: 205 case AMD64_GET_XFPUSTATE: 206 break; 207 208 case I386_SET_IOPERM: 209 default: 210 return (ECAPMODE); 211 } 212 } 213 #endif 214 215 if (uap->op == I386_GET_LDT || uap->op == I386_SET_LDT) 216 return (sysarch_ldt(td, uap, UIO_USERSPACE)); 217 /* 218 * XXXKIB check that the BSM generation code knows to encode 219 * the op argument. 220 */ 221 AUDIT_ARG_CMD(uap->op); 222 switch (uap->op) { 223 case I386_GET_IOPERM: 224 case I386_SET_IOPERM: 225 if ((error = copyin(uap->parms, &iargs, 226 sizeof(struct i386_ioperm_args))) != 0) 227 return (error); 228 break; 229 case I386_GET_XFPUSTATE: 230 if ((error = copyin(uap->parms, &i386xfpu, 231 sizeof(struct i386_get_xfpustate))) != 0) 232 return (error); 233 a64xfpu.addr = (void *)(uintptr_t)i386xfpu.addr; 234 a64xfpu.len = i386xfpu.len; 235 break; 236 case AMD64_GET_XFPUSTATE: 237 if ((error = copyin(uap->parms, &a64xfpu, 238 sizeof(struct amd64_get_xfpustate))) != 0) 239 return (error); 240 break; 241 default: 242 break; 243 } 244 245 switch (uap->op) { 246 case I386_GET_IOPERM: 247 error = amd64_get_ioperm(td, &iargs); 248 if (error == 0) 249 error = copyout(&iargs, uap->parms, 250 sizeof(struct i386_ioperm_args)); 251 break; 252 case I386_SET_IOPERM: 253 error = amd64_set_ioperm(td, &iargs); 254 break; 255 case I386_GET_FSBASE: 256 i386base = pcb->pcb_fsbase; 257 error = copyout(&i386base, uap->parms, sizeof(i386base)); 258 break; 259 case I386_SET_FSBASE: 260 error = copyin(uap->parms, &i386base, sizeof(i386base)); 261 if (!error) { 262 pcb->pcb_fsbase = i386base; 263 td->td_frame->tf_fs = _ufssel; 264 update_gdt_fsbase(td, i386base); 265 } 266 break; 267 case I386_GET_GSBASE: 268 i386base = pcb->pcb_gsbase; 269 error = copyout(&i386base, uap->parms, sizeof(i386base)); 270 break; 271 case I386_SET_GSBASE: 272 error = copyin(uap->parms, &i386base, sizeof(i386base)); 273 if (!error) { 274 pcb->pcb_gsbase = i386base; 275 td->td_frame->tf_gs = _ugssel; 276 update_gdt_gsbase(td, i386base); 277 } 278 break; 279 case AMD64_GET_FSBASE: 280 error = copyout(&pcb->pcb_fsbase, uap->parms, sizeof(pcb->pcb_fsbase)); 281 break; 282 283 case AMD64_SET_FSBASE: 284 error = copyin(uap->parms, &a64base, sizeof(a64base)); 285 if (!error) { 286 if (a64base < VM_MAXUSER_ADDRESS) { 287 pcb->pcb_fsbase = a64base; 288 set_pcb_flags(pcb, PCB_FULL_IRET); 289 td->td_frame->tf_fs = _ufssel; 290 } else 291 error = EINVAL; 292 } 293 break; 294 295 case AMD64_GET_GSBASE: 296 error = copyout(&pcb->pcb_gsbase, uap->parms, sizeof(pcb->pcb_gsbase)); 297 break; 298 299 case AMD64_SET_GSBASE: 300 error = copyin(uap->parms, &a64base, sizeof(a64base)); 301 if (!error) { 302 if (a64base < VM_MAXUSER_ADDRESS) { 303 pcb->pcb_gsbase = a64base; 304 set_pcb_flags(pcb, PCB_FULL_IRET); 305 td->td_frame->tf_gs = _ugssel; 306 } else 307 error = EINVAL; 308 } 309 break; 310 311 case I386_GET_XFPUSTATE: 312 case AMD64_GET_XFPUSTATE: 313 if (a64xfpu.len > cpu_max_ext_state_size - 314 sizeof(struct savefpu)) 315 return (EINVAL); 316 fpugetregs(td); 317 error = copyout((char *)(get_pcb_user_save_td(td) + 1), 318 a64xfpu.addr, a64xfpu.len); 319 return (error); 320 321 default: 322 error = EINVAL; 323 break; 324 } 325 return (error); 326 } 327 328 int 329 amd64_set_ioperm(td, uap) 330 struct thread *td; 331 struct i386_ioperm_args *uap; 332 { 333 int i, error; 334 char *iomap; 335 struct amd64tss *tssp; 336 struct system_segment_descriptor *tss_sd; 337 u_long *addr; 338 struct pcb *pcb; 339 340 if ((error = priv_check(td, PRIV_IO)) != 0) 341 return (error); 342 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 343 return (error); 344 if (uap->start + uap->length > IOPAGES * PAGE_SIZE * NBBY) 345 return (EINVAL); 346 347 /* 348 * XXX 349 * While this is restricted to root, we should probably figure out 350 * whether any other driver is using this i/o address, as so not to 351 * cause confusion. This probably requires a global 'usage registry'. 352 */ 353 pcb = td->td_pcb; 354 if (pcb->pcb_tssp == NULL) { 355 tssp = (struct amd64tss *)kmem_alloc(kernel_map, 356 ctob(IOPAGES+1)); 357 if (tssp == NULL) 358 return (ENOMEM); 359 iomap = (char *)&tssp[1]; 360 addr = (u_long *)iomap; 361 for (i = 0; i < (ctob(IOPAGES) + 1) / sizeof(u_long); i++) 362 *addr++ = ~0; 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_alloc(kernel_map, 463 max_ldt_segment * sizeof(struct user_segment_descriptor)); 464 if (new_ldt->ldt_base == NULL) { 465 FREE(new_ldt, M_SUBPROC); 466 mtx_lock(&dt_lock); 467 return (NULL); 468 } 469 new_ldt->ldt_refcnt = 1; 470 sldt.ssd_base = (uint64_t)new_ldt->ldt_base; 471 sldt.ssd_limit = max_ldt_segment * 472 sizeof(struct user_segment_descriptor) - 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 kmem_free(kernel_map, (vm_offset_t)new_ldt->ldt_base, 483 max_ldt_segment * sizeof(struct user_segment_descriptor)); 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 { 525 526 if (--pldt->ldt_refcnt == 0) { 527 kmem_free(kernel_map, (vm_offset_t)pldt->ldt_base, 528 max_ldt_segment * sizeof(struct user_segment_descriptor)); 529 free(pldt, M_SUBPROC); 530 } 531 } 532 533 void 534 user_ldt_deref(struct proc_ldt *pldt) 535 { 536 537 mtx_assert(&dt_lock, MA_OWNED); 538 user_ldt_derefl(pldt); 539 mtx_unlock(&dt_lock); 540 } 541 542 /* 543 * Note for the authors of compat layers (linux, etc): copyout() in 544 * the function below is not a problem since it presents data in 545 * arch-specific format (i.e. i386-specific in this case), not in 546 * the OS-specific one. 547 */ 548 int 549 amd64_get_ldt(td, uap) 550 struct thread *td; 551 struct i386_ldt_args *uap; 552 { 553 int error = 0; 554 struct proc_ldt *pldt; 555 int num; 556 struct user_segment_descriptor *lp; 557 558 #ifdef DEBUG 559 printf("amd64_get_ldt: start=%d num=%d descs=%p\n", 560 uap->start, uap->num, (void *)uap->descs); 561 #endif 562 563 if ((pldt = td->td_proc->p_md.md_ldt) != NULL) { 564 lp = &((struct user_segment_descriptor *)(pldt->ldt_base)) 565 [uap->start]; 566 num = min(uap->num, max_ldt_segment); 567 } else 568 return (EINVAL); 569 570 if ((uap->start > (unsigned int)max_ldt_segment) || 571 ((unsigned int)num > (unsigned int)max_ldt_segment) || 572 ((unsigned int)(uap->start + num) > (unsigned int)max_ldt_segment)) 573 return(EINVAL); 574 575 error = copyout(lp, uap->descs, num * 576 sizeof(struct user_segment_descriptor)); 577 if (!error) 578 td->td_retval[0] = num; 579 580 return(error); 581 } 582 583 int 584 amd64_set_ldt(td, uap, descs) 585 struct thread *td; 586 struct i386_ldt_args *uap; 587 struct user_segment_descriptor *descs; 588 { 589 int error = 0, i; 590 int largest_ld; 591 struct mdproc *mdp = &td->td_proc->p_md; 592 struct proc_ldt *pldt; 593 struct user_segment_descriptor *dp; 594 struct proc *p; 595 596 #ifdef DEBUG 597 printf("amd64_set_ldt: start=%d num=%d descs=%p\n", 598 uap->start, uap->num, (void *)uap->descs); 599 #endif 600 601 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 602 p = td->td_proc; 603 if (descs == NULL) { 604 /* Free descriptors */ 605 if (uap->start == 0 && uap->num == 0) 606 uap->num = max_ldt_segment; 607 if (uap->num == 0) 608 return (EINVAL); 609 if ((pldt = mdp->md_ldt) == NULL || 610 uap->start >= max_ldt_segment) 611 return (0); 612 largest_ld = uap->start + uap->num; 613 if (largest_ld > max_ldt_segment) 614 largest_ld = max_ldt_segment; 615 i = largest_ld - uap->start; 616 mtx_lock(&dt_lock); 617 bzero(&((struct user_segment_descriptor *)(pldt->ldt_base)) 618 [uap->start], sizeof(struct user_segment_descriptor) * i); 619 mtx_unlock(&dt_lock); 620 return (0); 621 } 622 623 if (!(uap->start == LDT_AUTO_ALLOC && uap->num == 1)) { 624 /* verify range of descriptors to modify */ 625 largest_ld = uap->start + uap->num; 626 if (uap->start >= max_ldt_segment || 627 largest_ld > max_ldt_segment) 628 return (EINVAL); 629 } 630 631 /* Check descriptors for access violations */ 632 for (i = 0; i < uap->num; i++) { 633 dp = &descs[i]; 634 635 switch (dp->sd_type) { 636 case SDT_SYSNULL: /* system null */ 637 dp->sd_p = 0; 638 break; 639 case SDT_SYS286TSS: 640 case SDT_SYSLDT: 641 case SDT_SYS286BSY: 642 case SDT_SYS286CGT: 643 case SDT_SYSTASKGT: 644 case SDT_SYS286IGT: 645 case SDT_SYS286TGT: 646 case SDT_SYSNULL2: 647 case SDT_SYSTSS: 648 case SDT_SYSNULL3: 649 case SDT_SYSBSY: 650 case SDT_SYSCGT: 651 case SDT_SYSNULL4: 652 case SDT_SYSIGT: 653 case SDT_SYSTGT: 654 /* I can't think of any reason to allow a user proc 655 * to create a segment of these types. They are 656 * for OS use only. 657 */ 658 return (EACCES); 659 /*NOTREACHED*/ 660 661 /* memory segment types */ 662 case SDT_MEMEC: /* memory execute only conforming */ 663 case SDT_MEMEAC: /* memory execute only accessed conforming */ 664 case SDT_MEMERC: /* memory execute read conforming */ 665 case SDT_MEMERAC: /* memory execute read accessed conforming */ 666 /* Must be "present" if executable and conforming. */ 667 if (dp->sd_p == 0) 668 return (EACCES); 669 break; 670 case SDT_MEMRO: /* memory read only */ 671 case SDT_MEMROA: /* memory read only accessed */ 672 case SDT_MEMRW: /* memory read write */ 673 case SDT_MEMRWA: /* memory read write accessed */ 674 case SDT_MEMROD: /* memory read only expand dwn limit */ 675 case SDT_MEMRODA: /* memory read only expand dwn lim accessed */ 676 case SDT_MEMRWD: /* memory read write expand dwn limit */ 677 case SDT_MEMRWDA: /* memory read write expand dwn lim acessed */ 678 case SDT_MEME: /* memory execute only */ 679 case SDT_MEMEA: /* memory execute only accessed */ 680 case SDT_MEMER: /* memory execute read */ 681 case SDT_MEMERA: /* memory execute read accessed */ 682 break; 683 default: 684 return(EINVAL); 685 /*NOTREACHED*/ 686 } 687 688 /* Only user (ring-3) descriptors may be present. */ 689 if ((dp->sd_p != 0) && (dp->sd_dpl != SEL_UPL)) 690 return (EACCES); 691 } 692 693 if (uap->start == LDT_AUTO_ALLOC && uap->num == 1) { 694 /* Allocate a free slot */ 695 mtx_lock(&dt_lock); 696 pldt = user_ldt_alloc(p, 0); 697 if (pldt == NULL) { 698 mtx_unlock(&dt_lock); 699 return (ENOMEM); 700 } 701 702 /* 703 * start scanning a bit up to leave room for NVidia and 704 * Wine, which still user the "Blat" method of allocation. 705 */ 706 i = 16; 707 dp = &((struct user_segment_descriptor *)(pldt->ldt_base))[i]; 708 for (; i < max_ldt_segment; ++i, ++dp) { 709 if (dp->sd_type == SDT_SYSNULL) 710 break; 711 } 712 if (i >= max_ldt_segment) { 713 mtx_unlock(&dt_lock); 714 return (ENOSPC); 715 } 716 uap->start = i; 717 error = amd64_set_ldt_data(td, i, 1, descs); 718 mtx_unlock(&dt_lock); 719 } else { 720 largest_ld = uap->start + uap->num; 721 if (largest_ld > max_ldt_segment) 722 return (EINVAL); 723 mtx_lock(&dt_lock); 724 if (user_ldt_alloc(p, 0) != NULL) { 725 error = amd64_set_ldt_data(td, uap->start, uap->num, 726 descs); 727 } 728 mtx_unlock(&dt_lock); 729 } 730 if (error == 0) 731 td->td_retval[0] = uap->start; 732 return (error); 733 } 734 735 int 736 amd64_set_ldt_data(struct thread *td, int start, int num, 737 struct user_segment_descriptor *descs) 738 { 739 struct mdproc *mdp = &td->td_proc->p_md; 740 struct proc_ldt *pldt = mdp->md_ldt; 741 742 mtx_assert(&dt_lock, MA_OWNED); 743 744 /* Fill in range */ 745 bcopy(descs, 746 &((struct user_segment_descriptor *)(pldt->ldt_base))[start], 747 num * sizeof(struct user_segment_descriptor)); 748 return (0); 749 }
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