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/10.2/sys/amd64/amd64/sys_machdep.c 307933 2016-10-25 17:11:11Z 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 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 #ifdef KTRACE
211 if (KTRPOINT(td, KTR_CAPFAIL))
212 ktrcapfail(CAPFAIL_SYSCALL, NULL, NULL);
213 #endif
214 return (ECAPMODE);
215 }
216 }
217 #endif
218
219 if (uap->op == I386_GET_LDT || uap->op == I386_SET_LDT)
220 return (sysarch_ldt(td, uap, UIO_USERSPACE));
221 /*
222 * XXXKIB check that the BSM generation code knows to encode
223 * the op argument.
224 */
225 AUDIT_ARG_CMD(uap->op);
226 switch (uap->op) {
227 case I386_GET_IOPERM:
228 case I386_SET_IOPERM:
229 if ((error = copyin(uap->parms, &iargs,
230 sizeof(struct i386_ioperm_args))) != 0)
231 return (error);
232 break;
233 case I386_GET_XFPUSTATE:
234 if ((error = copyin(uap->parms, &i386xfpu,
235 sizeof(struct i386_get_xfpustate))) != 0)
236 return (error);
237 a64xfpu.addr = (void *)(uintptr_t)i386xfpu.addr;
238 a64xfpu.len = i386xfpu.len;
239 break;
240 case AMD64_GET_XFPUSTATE:
241 if ((error = copyin(uap->parms, &a64xfpu,
242 sizeof(struct amd64_get_xfpustate))) != 0)
243 return (error);
244 break;
245 default:
246 break;
247 }
248
249 switch (uap->op) {
250 case I386_GET_IOPERM:
251 error = amd64_get_ioperm(td, &iargs);
252 if (error == 0)
253 error = copyout(&iargs, uap->parms,
254 sizeof(struct i386_ioperm_args));
255 break;
256 case I386_SET_IOPERM:
257 error = amd64_set_ioperm(td, &iargs);
258 break;
259 case I386_GET_FSBASE:
260 i386base = pcb->pcb_fsbase;
261 error = copyout(&i386base, uap->parms, sizeof(i386base));
262 break;
263 case I386_SET_FSBASE:
264 error = copyin(uap->parms, &i386base, sizeof(i386base));
265 if (!error) {
266 pcb->pcb_fsbase = i386base;
267 td->td_frame->tf_fs = _ufssel;
268 update_gdt_fsbase(td, i386base);
269 }
270 break;
271 case I386_GET_GSBASE:
272 i386base = pcb->pcb_gsbase;
273 error = copyout(&i386base, uap->parms, sizeof(i386base));
274 break;
275 case I386_SET_GSBASE:
276 error = copyin(uap->parms, &i386base, sizeof(i386base));
277 if (!error) {
278 pcb->pcb_gsbase = i386base;
279 td->td_frame->tf_gs = _ugssel;
280 update_gdt_gsbase(td, i386base);
281 }
282 break;
283 case AMD64_GET_FSBASE:
284 error = copyout(&pcb->pcb_fsbase, uap->parms, sizeof(pcb->pcb_fsbase));
285 break;
286
287 case AMD64_SET_FSBASE:
288 error = copyin(uap->parms, &a64base, sizeof(a64base));
289 if (!error) {
290 if (a64base < VM_MAXUSER_ADDRESS) {
291 pcb->pcb_fsbase = a64base;
292 set_pcb_flags(pcb, PCB_FULL_IRET);
293 td->td_frame->tf_fs = _ufssel;
294 } else
295 error = EINVAL;
296 }
297 break;
298
299 case AMD64_GET_GSBASE:
300 error = copyout(&pcb->pcb_gsbase, uap->parms, sizeof(pcb->pcb_gsbase));
301 break;
302
303 case AMD64_SET_GSBASE:
304 error = copyin(uap->parms, &a64base, sizeof(a64base));
305 if (!error) {
306 if (a64base < VM_MAXUSER_ADDRESS) {
307 pcb->pcb_gsbase = a64base;
308 set_pcb_flags(pcb, PCB_FULL_IRET);
309 td->td_frame->tf_gs = _ugssel;
310 } else
311 error = EINVAL;
312 }
313 break;
314
315 case I386_GET_XFPUSTATE:
316 case AMD64_GET_XFPUSTATE:
317 if (a64xfpu.len > cpu_max_ext_state_size -
318 sizeof(struct savefpu))
319 return (EINVAL);
320 fpugetregs(td);
321 error = copyout((char *)(get_pcb_user_save_td(td) + 1),
322 a64xfpu.addr, a64xfpu.len);
323 break;
324
325 default:
326 error = EINVAL;
327 break;
328 }
329 return (error);
330 }
331
332 int
333 amd64_set_ioperm(td, uap)
334 struct thread *td;
335 struct i386_ioperm_args *uap;
336 {
337 int i, error;
338 char *iomap;
339 struct amd64tss *tssp;
340 struct system_segment_descriptor *tss_sd;
341 u_long *addr;
342 struct pcb *pcb;
343
344 if ((error = priv_check(td, PRIV_IO)) != 0)
345 return (error);
346 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
347 return (error);
348 if (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 if (tssp == NULL)
362 return (ENOMEM);
363 iomap = (char *)&tssp[1];
364 addr = (u_long *)iomap;
365 for (i = 0; i < (ctob(IOPAGES) + 1) / sizeof(u_long); i++)
366 *addr++ = ~0;
367 critical_enter();
368 /* Takes care of tss_rsp0. */
369 memcpy(tssp, &common_tss[PCPU_GET(cpuid)],
370 sizeof(struct amd64tss));
371 tssp->tss_iobase = sizeof(*tssp);
372 pcb->pcb_tssp = tssp;
373 tss_sd = PCPU_GET(tss);
374 tss_sd->sd_lobase = (u_long)tssp & 0xffffff;
375 tss_sd->sd_hibase = ((u_long)tssp >> 24) & 0xfffffffffful;
376 tss_sd->sd_type = SDT_SYSTSS;
377 ltr(GSEL(GPROC0_SEL, SEL_KPL));
378 PCPU_SET(tssp, tssp);
379 critical_exit();
380 } else
381 iomap = (char *)&pcb->pcb_tssp[1];
382 for (i = uap->start; i < uap->start + uap->length; i++) {
383 if (uap->enable)
384 iomap[i >> 3] &= ~(1 << (i & 7));
385 else
386 iomap[i >> 3] |= (1 << (i & 7));
387 }
388 return (error);
389 }
390
391 int
392 amd64_get_ioperm(td, uap)
393 struct thread *td;
394 struct i386_ioperm_args *uap;
395 {
396 int i, state;
397 char *iomap;
398
399 if (uap->start >= IOPAGES * PAGE_SIZE * NBBY)
400 return (EINVAL);
401 if (td->td_pcb->pcb_tssp == NULL) {
402 uap->length = 0;
403 goto done;
404 }
405
406 iomap = (char *)&td->td_pcb->pcb_tssp[1];
407
408 i = uap->start;
409 state = (iomap[i >> 3] >> (i & 7)) & 1;
410 uap->enable = !state;
411 uap->length = 1;
412
413 for (i = uap->start + 1; i < IOPAGES * PAGE_SIZE * NBBY; i++) {
414 if (state != ((iomap[i >> 3] >> (i & 7)) & 1))
415 break;
416 uap->length++;
417 }
418
419 done:
420 return (0);
421 }
422
423 /*
424 * Update the GDT entry pointing to the LDT to point to the LDT of the
425 * current process.
426 */
427 void
428 set_user_ldt(struct mdproc *mdp)
429 {
430
431 critical_enter();
432 *PCPU_GET(ldt) = mdp->md_ldt_sd;
433 lldt(GSEL(GUSERLDT_SEL, SEL_KPL));
434 critical_exit();
435 }
436
437 #ifdef notyet
438 #ifdef SMP
439 static void
440 set_user_ldt_rv(struct vmspace *vmsp)
441 {
442 struct thread *td;
443
444 td = curthread;
445 if (vmsp != td->td_proc->p_vmspace)
446 return;
447
448 set_user_ldt(&td->td_proc->p_md);
449 }
450 #endif
451 #endif
452
453 struct proc_ldt *
454 user_ldt_alloc(struct proc *p, int force)
455 {
456 struct proc_ldt *pldt, *new_ldt;
457 struct mdproc *mdp;
458 struct soft_segment_descriptor sldt;
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 new_ldt->ldt_base = (caddr_t)kmem_malloc(kernel_arena,
467 max_ldt_segment * sizeof(struct user_segment_descriptor),
468 M_WAITOK | M_ZERO);
469 if (new_ldt->ldt_base == NULL) {
470 FREE(new_ldt, M_SUBPROC);
471 mtx_lock(&dt_lock);
472 return (NULL);
473 }
474 new_ldt->ldt_refcnt = 1;
475 sldt.ssd_base = (uint64_t)new_ldt->ldt_base;
476 sldt.ssd_limit = max_ldt_segment *
477 sizeof(struct user_segment_descriptor) - 1;
478 sldt.ssd_type = SDT_SYSLDT;
479 sldt.ssd_dpl = SEL_KPL;
480 sldt.ssd_p = 1;
481 sldt.ssd_long = 0;
482 sldt.ssd_def32 = 0;
483 sldt.ssd_gran = 0;
484 mtx_lock(&dt_lock);
485 pldt = mdp->md_ldt;
486 if (pldt != NULL && !force) {
487 kmem_free(kernel_arena, (vm_offset_t)new_ldt->ldt_base,
488 max_ldt_segment * sizeof(struct user_segment_descriptor));
489 free(new_ldt, M_SUBPROC);
490 return (pldt);
491 }
492
493 if (pldt != NULL) {
494 bcopy(pldt->ldt_base, new_ldt->ldt_base, max_ldt_segment *
495 sizeof(struct user_segment_descriptor));
496 user_ldt_derefl(pldt);
497 }
498 ssdtosyssd(&sldt, &p->p_md.md_ldt_sd);
499 atomic_store_rel_ptr((volatile uintptr_t *)&mdp->md_ldt,
500 (uintptr_t)new_ldt);
501 if (p == curproc)
502 set_user_ldt(mdp);
503
504 return (mdp->md_ldt);
505 }
506
507 void
508 user_ldt_free(struct thread *td)
509 {
510 struct proc *p = td->td_proc;
511 struct mdproc *mdp = &p->p_md;
512 struct proc_ldt *pldt;
513
514 mtx_assert(&dt_lock, MA_OWNED);
515 if ((pldt = mdp->md_ldt) == NULL) {
516 mtx_unlock(&dt_lock);
517 return;
518 }
519
520 mdp->md_ldt = NULL;
521 bzero(&mdp->md_ldt_sd, sizeof(mdp->md_ldt_sd));
522 if (td == curthread)
523 lldt(GSEL(GNULL_SEL, SEL_KPL));
524 user_ldt_deref(pldt);
525 }
526
527 static void
528 user_ldt_derefl(struct proc_ldt *pldt)
529 {
530
531 if (--pldt->ldt_refcnt == 0) {
532 kmem_free(kernel_arena, (vm_offset_t)pldt->ldt_base,
533 max_ldt_segment * sizeof(struct user_segment_descriptor));
534 free(pldt, M_SUBPROC);
535 }
536 }
537
538 void
539 user_ldt_deref(struct proc_ldt *pldt)
540 {
541
542 mtx_assert(&dt_lock, MA_OWNED);
543 user_ldt_derefl(pldt);
544 mtx_unlock(&dt_lock);
545 }
546
547 /*
548 * Note for the authors of compat layers (linux, etc): copyout() in
549 * the function below is not a problem since it presents data in
550 * arch-specific format (i.e. i386-specific in this case), not in
551 * the OS-specific one.
552 */
553 int
554 amd64_get_ldt(td, uap)
555 struct thread *td;
556 struct i386_ldt_args *uap;
557 {
558 int error = 0;
559 struct proc_ldt *pldt;
560 int num;
561 struct user_segment_descriptor *lp;
562
563 #ifdef DEBUG
564 printf("amd64_get_ldt: start=%d num=%d descs=%p\n",
565 uap->start, uap->num, (void *)uap->descs);
566 #endif
567
568 if ((pldt = td->td_proc->p_md.md_ldt) != NULL) {
569 lp = &((struct user_segment_descriptor *)(pldt->ldt_base))
570 [uap->start];
571 num = min(uap->num, max_ldt_segment);
572 } else
573 return (EINVAL);
574
575 if ((uap->start > (unsigned int)max_ldt_segment) ||
576 ((unsigned int)num > (unsigned int)max_ldt_segment) ||
577 ((unsigned int)(uap->start + num) > (unsigned int)max_ldt_segment))
578 return(EINVAL);
579
580 error = copyout(lp, uap->descs, num *
581 sizeof(struct user_segment_descriptor));
582 if (!error)
583 td->td_retval[0] = num;
584
585 return(error);
586 }
587
588 int
589 amd64_set_ldt(td, uap, descs)
590 struct thread *td;
591 struct i386_ldt_args *uap;
592 struct user_segment_descriptor *descs;
593 {
594 int error = 0;
595 unsigned int largest_ld, i;
596 struct mdproc *mdp = &td->td_proc->p_md;
597 struct proc_ldt *pldt;
598 struct user_segment_descriptor *dp;
599 struct proc *p;
600
601 #ifdef DEBUG
602 printf("amd64_set_ldt: start=%d num=%d descs=%p\n",
603 uap->start, uap->num, (void *)uap->descs);
604 #endif
605
606 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
607 p = td->td_proc;
608 if (descs == NULL) {
609 /* Free descriptors */
610 if (uap->start == 0 && uap->num == 0)
611 uap->num = max_ldt_segment;
612 if (uap->num == 0)
613 return (EINVAL);
614 if ((pldt = mdp->md_ldt) == NULL ||
615 uap->start >= max_ldt_segment)
616 return (0);
617 largest_ld = uap->start + uap->num;
618 if (largest_ld > max_ldt_segment)
619 largest_ld = max_ldt_segment;
620 if (largest_ld < uap->start)
621 return (EINVAL);
622 i = largest_ld - uap->start;
623 mtx_lock(&dt_lock);
624 bzero(&((struct user_segment_descriptor *)(pldt->ldt_base))
625 [uap->start], sizeof(struct user_segment_descriptor) * i);
626 mtx_unlock(&dt_lock);
627 return (0);
628 }
629
630 if (!(uap->start == LDT_AUTO_ALLOC && uap->num == 1)) {
631 /* verify range of descriptors to modify */
632 largest_ld = uap->start + uap->num;
633 if (uap->start >= max_ldt_segment ||
634 largest_ld > max_ldt_segment ||
635 largest_ld < uap->start)
636 return (EINVAL);
637 }
638
639 /* Check descriptors for access violations */
640 for (i = 0; i < uap->num; i++) {
641 dp = &descs[i];
642
643 switch (dp->sd_type) {
644 case SDT_SYSNULL: /* system null */
645 dp->sd_p = 0;
646 break;
647 case SDT_SYS286TSS:
648 case SDT_SYSLDT:
649 case SDT_SYS286BSY:
650 case SDT_SYS286CGT:
651 case SDT_SYSTASKGT:
652 case SDT_SYS286IGT:
653 case SDT_SYS286TGT:
654 case SDT_SYSNULL2:
655 case SDT_SYSTSS:
656 case SDT_SYSNULL3:
657 case SDT_SYSBSY:
658 case SDT_SYSCGT:
659 case SDT_SYSNULL4:
660 case SDT_SYSIGT:
661 case SDT_SYSTGT:
662 /* I can't think of any reason to allow a user proc
663 * to create a segment of these types. They are
664 * for OS use only.
665 */
666 return (EACCES);
667 /*NOTREACHED*/
668
669 /* memory segment types */
670 case SDT_MEMEC: /* memory execute only conforming */
671 case SDT_MEMEAC: /* memory execute only accessed conforming */
672 case SDT_MEMERC: /* memory execute read conforming */
673 case SDT_MEMERAC: /* memory execute read accessed conforming */
674 /* Must be "present" if executable and conforming. */
675 if (dp->sd_p == 0)
676 return (EACCES);
677 break;
678 case SDT_MEMRO: /* memory read only */
679 case SDT_MEMROA: /* memory read only accessed */
680 case SDT_MEMRW: /* memory read write */
681 case SDT_MEMRWA: /* memory read write accessed */
682 case SDT_MEMROD: /* memory read only expand dwn limit */
683 case SDT_MEMRODA: /* memory read only expand dwn lim accessed */
684 case SDT_MEMRWD: /* memory read write expand dwn limit */
685 case SDT_MEMRWDA: /* memory read write expand dwn lim acessed */
686 case SDT_MEME: /* memory execute only */
687 case SDT_MEMEA: /* memory execute only accessed */
688 case SDT_MEMER: /* memory execute read */
689 case SDT_MEMERA: /* memory execute read accessed */
690 break;
691 default:
692 return(EINVAL);
693 /*NOTREACHED*/
694 }
695
696 /* Only user (ring-3) descriptors may be present. */
697 if ((dp->sd_p != 0) && (dp->sd_dpl != SEL_UPL))
698 return (EACCES);
699 }
700
701 if (uap->start == LDT_AUTO_ALLOC && uap->num == 1) {
702 /* Allocate a free slot */
703 mtx_lock(&dt_lock);
704 pldt = user_ldt_alloc(p, 0);
705 if (pldt == NULL) {
706 mtx_unlock(&dt_lock);
707 return (ENOMEM);
708 }
709
710 /*
711 * start scanning a bit up to leave room for NVidia and
712 * Wine, which still user the "Blat" method of allocation.
713 */
714 i = 16;
715 dp = &((struct user_segment_descriptor *)(pldt->ldt_base))[i];
716 for (; i < max_ldt_segment; ++i, ++dp) {
717 if (dp->sd_type == SDT_SYSNULL)
718 break;
719 }
720 if (i >= max_ldt_segment) {
721 mtx_unlock(&dt_lock);
722 return (ENOSPC);
723 }
724 uap->start = i;
725 error = amd64_set_ldt_data(td, i, 1, descs);
726 mtx_unlock(&dt_lock);
727 } else {
728 largest_ld = uap->start + uap->num;
729 if (largest_ld > max_ldt_segment)
730 return (EINVAL);
731 mtx_lock(&dt_lock);
732 if (user_ldt_alloc(p, 0) != NULL) {
733 error = amd64_set_ldt_data(td, uap->start, uap->num,
734 descs);
735 }
736 mtx_unlock(&dt_lock);
737 }
738 if (error == 0)
739 td->td_retval[0] = uap->start;
740 return (error);
741 }
742
743 int
744 amd64_set_ldt_data(struct thread *td, int start, int num,
745 struct user_segment_descriptor *descs)
746 {
747 struct mdproc *mdp = &td->td_proc->p_md;
748 struct proc_ldt *pldt = mdp->md_ldt;
749
750 mtx_assert(&dt_lock, MA_OWNED);
751
752 /* Fill in range */
753 bcopy(descs,
754 &((struct user_segment_descriptor *)(pldt->ldt_base))[start],
755 num * sizeof(struct user_segment_descriptor));
756 return (0);
757 }
Cache object: 502df3ec6f47b4dd0e68c7cf13370348
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