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/8.3/sys/amd64/amd64/sys_machdep.c 220651 2011-04-15 10:33:20Z kib $");
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
39 #include <sys/lock.h>
40 #include <sys/malloc.h>
41 #include <sys/mutex.h>
42 #include <sys/priv.h>
43 #include <sys/proc.h>
44 #include <sys/sysproto.h>
45 #include <sys/uio.h>
46
47 #include <vm/vm.h>
48 #include <vm/pmap.h>
49 #include <vm/vm_kern.h> /* for kernel_map */
50 #include <vm/vm_extern.h>
51
52 #include <machine/frame.h>
53 #include <machine/md_var.h>
54 #include <machine/pcb.h>
55 #include <machine/specialreg.h>
56 #include <machine/sysarch.h>
57 #include <machine/tss.h>
58 #include <machine/vmparam.h>
59
60 #include <security/audit/audit.h>
61
62 #define MAX_LD 8192
63
64 int max_ldt_segment = 1024;
65 SYSCTL_INT(_machdep, OID_AUTO, max_ldt_segment, CTLFLAG_RDTUN,
66 &max_ldt_segment, 0,
67 "Maximum number of allowed LDT segments in the single address space");
68
69 static void
70 max_ldt_segment_init(void *arg __unused)
71 {
72
73 TUNABLE_INT_FETCH("machdep.max_ldt_segment", &max_ldt_segment);
74 if (max_ldt_segment <= 0)
75 max_ldt_segment = 1;
76 if (max_ldt_segment > MAX_LD)
77 max_ldt_segment = MAX_LD;
78 }
79 SYSINIT(maxldt, SI_SUB_VM_CONF, SI_ORDER_ANY, max_ldt_segment_init, NULL);
80
81 #ifdef notyet
82 #ifdef SMP
83 static void set_user_ldt_rv(struct vmspace *vmsp);
84 #endif
85 #endif
86 static void user_ldt_derefl(struct proc_ldt *pldt);
87
88 #ifndef _SYS_SYSPROTO_H_
89 struct sysarch_args {
90 int op;
91 char *parms;
92 };
93 #endif
94
95 int
96 sysarch_ldt(struct thread *td, struct sysarch_args *uap, int uap_space)
97 {
98 struct i386_ldt_args *largs, la;
99 struct user_segment_descriptor *lp;
100 int error = 0;
101
102 /*
103 * XXXKIB check that the BSM generation code knows to encode
104 * the op argument.
105 */
106 AUDIT_ARG_CMD(uap->op);
107 if (uap_space == UIO_USERSPACE) {
108 error = copyin(uap->parms, &la, sizeof(struct i386_ldt_args));
109 if (error != 0)
110 return (error);
111 largs = &la;
112 } else
113 largs = (struct i386_ldt_args *)uap->parms;
114 if (largs->num > max_ldt_segment || largs->num <= 0)
115 return (EINVAL);
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 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
123 if (largs->descs != NULL) {
124 lp = malloc(largs->num * sizeof(struct
125 user_segment_descriptor), M_TEMP, M_WAITOK);
126 error = copyin(largs->descs, lp, largs->num *
127 sizeof(struct user_segment_descriptor));
128 if (error == 0)
129 error = amd64_set_ldt(td, largs, lp);
130 free(lp, M_TEMP);
131 } else {
132 error = amd64_set_ldt(td, largs, NULL);
133 }
134 break;
135 }
136 return (error);
137 }
138
139 void
140 update_gdt_gsbase(struct thread *td, uint32_t base)
141 {
142 struct user_segment_descriptor *sd;
143
144 if (td != curthread)
145 return;
146 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
147 critical_enter();
148 sd = PCPU_GET(gs32p);
149 sd->sd_lobase = base & 0xffffff;
150 sd->sd_hibase = (base >> 24) & 0xff;
151 critical_exit();
152 }
153
154 void
155 update_gdt_fsbase(struct thread *td, uint32_t base)
156 {
157 struct user_segment_descriptor *sd;
158
159 if (td != curthread)
160 return;
161 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
162 critical_enter();
163 sd = PCPU_GET(fs32p);
164 sd->sd_lobase = base & 0xffffff;
165 sd->sd_hibase = (base >> 24) & 0xff;
166 critical_exit();
167 }
168
169 int
170 sysarch(td, uap)
171 struct thread *td;
172 register struct sysarch_args *uap;
173 {
174 int error = 0;
175 struct pcb *pcb = curthread->td_pcb;
176 uint32_t i386base;
177 uint64_t a64base;
178 struct i386_ioperm_args iargs;
179
180 if (uap->op == I386_GET_LDT || uap->op == I386_SET_LDT)
181 return (sysarch_ldt(td, uap, UIO_USERSPACE));
182 /*
183 * XXXKIB check that the BSM generation code knows to encode
184 * the op argument.
185 */
186 AUDIT_ARG_CMD(uap->op);
187 switch (uap->op) {
188 case I386_GET_IOPERM:
189 case I386_SET_IOPERM:
190 if ((error = copyin(uap->parms, &iargs,
191 sizeof(struct i386_ioperm_args))) != 0)
192 return (error);
193 break;
194 default:
195 break;
196 }
197
198 switch (uap->op) {
199 case I386_GET_IOPERM:
200 error = amd64_get_ioperm(td, &iargs);
201 if (error == 0)
202 error = copyout(&iargs, uap->parms,
203 sizeof(struct i386_ioperm_args));
204 break;
205 case I386_SET_IOPERM:
206 error = amd64_set_ioperm(td, &iargs);
207 break;
208 case I386_GET_FSBASE:
209 i386base = pcb->pcb_fsbase;
210 error = copyout(&i386base, uap->parms, sizeof(i386base));
211 break;
212 case I386_SET_FSBASE:
213 error = copyin(uap->parms, &i386base, sizeof(i386base));
214 if (!error) {
215 pcb->pcb_fsbase = i386base;
216 td->td_frame->tf_fs = _ufssel;
217 update_gdt_fsbase(td, i386base);
218 }
219 break;
220 case I386_GET_GSBASE:
221 i386base = pcb->pcb_gsbase;
222 error = copyout(&i386base, uap->parms, sizeof(i386base));
223 break;
224 case I386_SET_GSBASE:
225 error = copyin(uap->parms, &i386base, sizeof(i386base));
226 if (!error) {
227 pcb->pcb_gsbase = i386base;
228 td->td_frame->tf_gs = _ugssel;
229 update_gdt_gsbase(td, i386base);
230 }
231 break;
232 case AMD64_GET_FSBASE:
233 error = copyout(&pcb->pcb_fsbase, uap->parms, sizeof(pcb->pcb_fsbase));
234 break;
235
236 case AMD64_SET_FSBASE:
237 error = copyin(uap->parms, &a64base, sizeof(a64base));
238 if (!error) {
239 if (a64base < VM_MAXUSER_ADDRESS) {
240 pcb->pcb_fsbase = a64base;
241 set_pcb_flags(pcb, PCB_FULL_IRET);
242 td->td_frame->tf_fs = _ufssel;
243 } else
244 error = EINVAL;
245 }
246 break;
247
248 case AMD64_GET_GSBASE:
249 error = copyout(&pcb->pcb_gsbase, uap->parms, sizeof(pcb->pcb_gsbase));
250 break;
251
252 case AMD64_SET_GSBASE:
253 error = copyin(uap->parms, &a64base, sizeof(a64base));
254 if (!error) {
255 if (a64base < VM_MAXUSER_ADDRESS) {
256 pcb->pcb_gsbase = a64base;
257 set_pcb_flags(pcb, PCB_FULL_IRET);
258 td->td_frame->tf_gs = _ugssel;
259 } else
260 error = EINVAL;
261 }
262 break;
263
264 default:
265 error = EINVAL;
266 break;
267 }
268 return (error);
269 }
270
271 int
272 amd64_set_ioperm(td, uap)
273 struct thread *td;
274 struct i386_ioperm_args *uap;
275 {
276 int i, error;
277 char *iomap;
278 struct amd64tss *tssp;
279 struct system_segment_descriptor *tss_sd;
280 u_long *addr;
281 struct pcb *pcb;
282
283 if ((error = priv_check(td, PRIV_IO)) != 0)
284 return (error);
285 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
286 return (error);
287 if (uap->start + uap->length > IOPAGES * PAGE_SIZE * NBBY)
288 return (EINVAL);
289
290 /*
291 * XXX
292 * While this is restricted to root, we should probably figure out
293 * whether any other driver is using this i/o address, as so not to
294 * cause confusion. This probably requires a global 'usage registry'.
295 */
296 pcb = td->td_pcb;
297 if (pcb->pcb_tssp == NULL) {
298 tssp = (struct amd64tss *)kmem_alloc(kernel_map,
299 ctob(IOPAGES+1));
300 if (tssp == NULL)
301 return (ENOMEM);
302 iomap = (char *)&tssp[1];
303 addr = (u_long *)iomap;
304 for (i = 0; i < (ctob(IOPAGES) + 1) / sizeof(u_long); i++)
305 *addr++ = ~0;
306 critical_enter();
307 /* Takes care of tss_rsp0. */
308 memcpy(tssp, &common_tss[PCPU_GET(cpuid)],
309 sizeof(struct amd64tss));
310 tssp->tss_iobase = sizeof(*tssp);
311 pcb->pcb_tssp = tssp;
312 tss_sd = PCPU_GET(tss);
313 tss_sd->sd_lobase = (u_long)tssp & 0xffffff;
314 tss_sd->sd_hibase = ((u_long)tssp >> 24) & 0xfffffffffful;
315 tss_sd->sd_type = SDT_SYSTSS;
316 ltr(GSEL(GPROC0_SEL, SEL_KPL));
317 PCPU_SET(tssp, tssp);
318 critical_exit();
319 } else
320 iomap = (char *)&pcb->pcb_tssp[1];
321 for (i = uap->start; i < uap->start + uap->length; i++) {
322 if (uap->enable)
323 iomap[i >> 3] &= ~(1 << (i & 7));
324 else
325 iomap[i >> 3] |= (1 << (i & 7));
326 }
327 return (error);
328 }
329
330 int
331 amd64_get_ioperm(td, uap)
332 struct thread *td;
333 struct i386_ioperm_args *uap;
334 {
335 int i, state;
336 char *iomap;
337
338 if (uap->start >= IOPAGES * PAGE_SIZE * NBBY)
339 return (EINVAL);
340 if (td->td_pcb->pcb_tssp == NULL) {
341 uap->length = 0;
342 goto done;
343 }
344
345 iomap = (char *)&td->td_pcb->pcb_tssp[1];
346
347 i = uap->start;
348 state = (iomap[i >> 3] >> (i & 7)) & 1;
349 uap->enable = !state;
350 uap->length = 1;
351
352 for (i = uap->start + 1; i < IOPAGES * PAGE_SIZE * NBBY; i++) {
353 if (state != ((iomap[i >> 3] >> (i & 7)) & 1))
354 break;
355 uap->length++;
356 }
357
358 done:
359 return (0);
360 }
361
362 /*
363 * Update the GDT entry pointing to the LDT to point to the LDT of the
364 * current process.
365 */
366 void
367 set_user_ldt(struct mdproc *mdp)
368 {
369
370 critical_enter();
371 *PCPU_GET(ldt) = mdp->md_ldt_sd;
372 lldt(GSEL(GUSERLDT_SEL, SEL_KPL));
373 critical_exit();
374 }
375
376 #ifdef notyet
377 #ifdef SMP
378 static void
379 set_user_ldt_rv(struct vmspace *vmsp)
380 {
381 struct thread *td;
382
383 td = curthread;
384 if (vmsp != td->td_proc->p_vmspace)
385 return;
386
387 set_user_ldt(&td->td_proc->p_md);
388 }
389 #endif
390 #endif
391
392 struct proc_ldt *
393 user_ldt_alloc(struct proc *p, int force)
394 {
395 struct proc_ldt *pldt, *new_ldt;
396 struct mdproc *mdp;
397 struct soft_segment_descriptor sldt;
398
399 mtx_assert(&dt_lock, MA_OWNED);
400 mdp = &p->p_md;
401 if (!force && mdp->md_ldt != NULL)
402 return (mdp->md_ldt);
403 mtx_unlock(&dt_lock);
404 new_ldt = malloc(sizeof(struct proc_ldt), M_SUBPROC, M_WAITOK);
405 new_ldt->ldt_base = (caddr_t)kmem_alloc(kernel_map,
406 max_ldt_segment * sizeof(struct user_segment_descriptor));
407 if (new_ldt->ldt_base == NULL) {
408 FREE(new_ldt, M_SUBPROC);
409 mtx_lock(&dt_lock);
410 return (NULL);
411 }
412 new_ldt->ldt_refcnt = 1;
413 sldt.ssd_base = (uint64_t)new_ldt->ldt_base;
414 sldt.ssd_limit = max_ldt_segment *
415 sizeof(struct user_segment_descriptor) - 1;
416 sldt.ssd_type = SDT_SYSLDT;
417 sldt.ssd_dpl = SEL_KPL;
418 sldt.ssd_p = 1;
419 sldt.ssd_long = 0;
420 sldt.ssd_def32 = 0;
421 sldt.ssd_gran = 0;
422 mtx_lock(&dt_lock);
423 pldt = mdp->md_ldt;
424 if (pldt != NULL && !force) {
425 kmem_free(kernel_map, (vm_offset_t)new_ldt->ldt_base,
426 max_ldt_segment * sizeof(struct user_segment_descriptor));
427 free(new_ldt, M_SUBPROC);
428 return (pldt);
429 }
430
431 if (pldt != NULL) {
432 bcopy(pldt->ldt_base, new_ldt->ldt_base, max_ldt_segment *
433 sizeof(struct user_segment_descriptor));
434 user_ldt_derefl(pldt);
435 }
436 ssdtosyssd(&sldt, &p->p_md.md_ldt_sd);
437 atomic_store_rel_ptr((volatile uintptr_t *)&mdp->md_ldt,
438 (uintptr_t)new_ldt);
439 if (p == curproc)
440 set_user_ldt(mdp);
441
442 return (mdp->md_ldt);
443 }
444
445 void
446 user_ldt_free(struct thread *td)
447 {
448 struct proc *p = td->td_proc;
449 struct mdproc *mdp = &p->p_md;
450 struct proc_ldt *pldt;
451
452 mtx_assert(&dt_lock, MA_OWNED);
453 if ((pldt = mdp->md_ldt) == NULL) {
454 mtx_unlock(&dt_lock);
455 return;
456 }
457
458 mdp->md_ldt = NULL;
459 bzero(&mdp->md_ldt_sd, sizeof(mdp->md_ldt_sd));
460 if (td == curthread)
461 lldt(GSEL(GNULL_SEL, SEL_KPL));
462 user_ldt_deref(pldt);
463 }
464
465 static void
466 user_ldt_derefl(struct proc_ldt *pldt)
467 {
468
469 if (--pldt->ldt_refcnt == 0) {
470 kmem_free(kernel_map, (vm_offset_t)pldt->ldt_base,
471 max_ldt_segment * sizeof(struct user_segment_descriptor));
472 free(pldt, M_SUBPROC);
473 }
474 }
475
476 void
477 user_ldt_deref(struct proc_ldt *pldt)
478 {
479
480 mtx_assert(&dt_lock, MA_OWNED);
481 user_ldt_derefl(pldt);
482 mtx_unlock(&dt_lock);
483 }
484
485 /*
486 * Note for the authors of compat layers (linux, etc): copyout() in
487 * the function below is not a problem since it presents data in
488 * arch-specific format (i.e. i386-specific in this case), not in
489 * the OS-specific one.
490 */
491 int
492 amd64_get_ldt(td, uap)
493 struct thread *td;
494 struct i386_ldt_args *uap;
495 {
496 int error = 0;
497 struct proc_ldt *pldt;
498 int num;
499 struct user_segment_descriptor *lp;
500
501 #ifdef DEBUG
502 printf("amd64_get_ldt: start=%d num=%d descs=%p\n",
503 uap->start, uap->num, (void *)uap->descs);
504 #endif
505
506 if ((pldt = td->td_proc->p_md.md_ldt) != NULL) {
507 lp = &((struct user_segment_descriptor *)(pldt->ldt_base))
508 [uap->start];
509 num = min(uap->num, max_ldt_segment);
510 } else
511 return (EINVAL);
512
513 if ((uap->start > (unsigned int)max_ldt_segment) ||
514 ((unsigned int)num > (unsigned int)max_ldt_segment) ||
515 ((unsigned int)(uap->start + num) > (unsigned int)max_ldt_segment))
516 return(EINVAL);
517
518 error = copyout(lp, uap->descs, num *
519 sizeof(struct user_segment_descriptor));
520 if (!error)
521 td->td_retval[0] = num;
522
523 return(error);
524 }
525
526 int
527 amd64_set_ldt(td, uap, descs)
528 struct thread *td;
529 struct i386_ldt_args *uap;
530 struct user_segment_descriptor *descs;
531 {
532 int error = 0, i;
533 int largest_ld;
534 struct mdproc *mdp = &td->td_proc->p_md;
535 struct proc_ldt *pldt;
536 struct user_segment_descriptor *dp;
537 struct proc *p;
538
539 #ifdef DEBUG
540 printf("amd64_set_ldt: start=%d num=%d descs=%p\n",
541 uap->start, uap->num, (void *)uap->descs);
542 #endif
543
544 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
545 p = td->td_proc;
546 if (descs == NULL) {
547 /* Free descriptors */
548 if (uap->start == 0 && uap->num == 0)
549 uap->num = max_ldt_segment;
550 if (uap->num <= 0)
551 return (EINVAL);
552 if ((pldt = mdp->md_ldt) == NULL ||
553 uap->start >= max_ldt_segment)
554 return (0);
555 largest_ld = uap->start + uap->num;
556 if (largest_ld > max_ldt_segment)
557 largest_ld = max_ldt_segment;
558 i = largest_ld - uap->start;
559 mtx_lock(&dt_lock);
560 bzero(&((struct user_segment_descriptor *)(pldt->ldt_base))
561 [uap->start], sizeof(struct user_segment_descriptor) * i);
562 mtx_unlock(&dt_lock);
563 return (0);
564 }
565
566 if (!(uap->start == LDT_AUTO_ALLOC && uap->num == 1)) {
567 /* verify range of descriptors to modify */
568 largest_ld = uap->start + uap->num;
569 if (uap->start >= max_ldt_segment ||
570 uap->num < 0 || largest_ld > max_ldt_segment)
571 return (EINVAL);
572 }
573
574 /* Check descriptors for access violations */
575 for (i = 0; i < uap->num; i++) {
576 dp = &descs[i];
577
578 switch (dp->sd_type) {
579 case SDT_SYSNULL: /* system null */
580 dp->sd_p = 0;
581 break;
582 case SDT_SYS286TSS:
583 case SDT_SYSLDT:
584 case SDT_SYS286BSY:
585 case SDT_SYS286CGT:
586 case SDT_SYSTASKGT:
587 case SDT_SYS286IGT:
588 case SDT_SYS286TGT:
589 case SDT_SYSNULL2:
590 case SDT_SYSTSS:
591 case SDT_SYSNULL3:
592 case SDT_SYSBSY:
593 case SDT_SYSCGT:
594 case SDT_SYSNULL4:
595 case SDT_SYSIGT:
596 case SDT_SYSTGT:
597 /* I can't think of any reason to allow a user proc
598 * to create a segment of these types. They are
599 * for OS use only.
600 */
601 return (EACCES);
602 /*NOTREACHED*/
603
604 /* memory segment types */
605 case SDT_MEMEC: /* memory execute only conforming */
606 case SDT_MEMEAC: /* memory execute only accessed conforming */
607 case SDT_MEMERC: /* memory execute read conforming */
608 case SDT_MEMERAC: /* memory execute read accessed conforming */
609 /* Must be "present" if executable and conforming. */
610 if (dp->sd_p == 0)
611 return (EACCES);
612 break;
613 case SDT_MEMRO: /* memory read only */
614 case SDT_MEMROA: /* memory read only accessed */
615 case SDT_MEMRW: /* memory read write */
616 case SDT_MEMRWA: /* memory read write accessed */
617 case SDT_MEMROD: /* memory read only expand dwn limit */
618 case SDT_MEMRODA: /* memory read only expand dwn lim accessed */
619 case SDT_MEMRWD: /* memory read write expand dwn limit */
620 case SDT_MEMRWDA: /* memory read write expand dwn lim acessed */
621 case SDT_MEME: /* memory execute only */
622 case SDT_MEMEA: /* memory execute only accessed */
623 case SDT_MEMER: /* memory execute read */
624 case SDT_MEMERA: /* memory execute read accessed */
625 break;
626 default:
627 return(EINVAL);
628 /*NOTREACHED*/
629 }
630
631 /* Only user (ring-3) descriptors may be present. */
632 if ((dp->sd_p != 0) && (dp->sd_dpl != SEL_UPL))
633 return (EACCES);
634 }
635
636 if (uap->start == LDT_AUTO_ALLOC && uap->num == 1) {
637 /* Allocate a free slot */
638 mtx_lock(&dt_lock);
639 pldt = user_ldt_alloc(p, 0);
640 if (pldt == NULL) {
641 mtx_unlock(&dt_lock);
642 return (ENOMEM);
643 }
644
645 /*
646 * start scanning a bit up to leave room for NVidia and
647 * Wine, which still user the "Blat" method of allocation.
648 */
649 i = 16;
650 dp = &((struct user_segment_descriptor *)(pldt->ldt_base))[i];
651 for (; i < max_ldt_segment; ++i, ++dp) {
652 if (dp->sd_type == SDT_SYSNULL)
653 break;
654 }
655 if (i >= max_ldt_segment) {
656 mtx_unlock(&dt_lock);
657 return (ENOSPC);
658 }
659 uap->start = i;
660 error = amd64_set_ldt_data(td, i, 1, descs);
661 mtx_unlock(&dt_lock);
662 } else {
663 largest_ld = uap->start + uap->num;
664 if (largest_ld > max_ldt_segment)
665 return (EINVAL);
666 mtx_lock(&dt_lock);
667 if (user_ldt_alloc(p, 0) != NULL) {
668 error = amd64_set_ldt_data(td, uap->start, uap->num,
669 descs);
670 }
671 mtx_unlock(&dt_lock);
672 }
673 if (error == 0)
674 td->td_retval[0] = uap->start;
675 return (error);
676 }
677
678 int
679 amd64_set_ldt_data(struct thread *td, int start, int num,
680 struct user_segment_descriptor *descs)
681 {
682 struct mdproc *mdp = &td->td_proc->p_md;
683 struct proc_ldt *pldt = mdp->md_ldt;
684
685 mtx_assert(&dt_lock, MA_OWNED);
686
687 /* Fill in range */
688 bcopy(descs,
689 &((struct user_segment_descriptor *)(pldt->ldt_base))[start],
690 num * sizeof(struct user_segment_descriptor));
691 return (0);
692 }
Cache object: d709b26d94a15cffae351bdb332efaad
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