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("$FreeBSD$");
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 char *iomap;
338 struct amd64tss *tssp;
339 struct system_segment_descriptor *tss_sd;
340 u_long *addr;
341 struct pcb *pcb;
342 u_int i;
343 int error;
344
345 if ((error = priv_check(td, PRIV_IO)) != 0)
346 return (error);
347 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
348 return (error);
349 if (uap->start > uap->start + uap->length ||
350 uap->start + uap->length > IOPAGES * PAGE_SIZE * NBBY)
351 return (EINVAL);
352
353 /*
354 * XXX
355 * While this is restricted to root, we should probably figure out
356 * whether any other driver is using this i/o address, as so not to
357 * cause confusion. This probably requires a global 'usage registry'.
358 */
359 pcb = td->td_pcb;
360 if (pcb->pcb_tssp == NULL) {
361 tssp = (struct amd64tss *)kmem_malloc(kernel_arena,
362 ctob(IOPAGES+1), M_WAITOK);
363 if (tssp == NULL)
364 return (ENOMEM);
365 iomap = (char *)&tssp[1];
366 addr = (u_long *)iomap;
367 for (i = 0; i < (ctob(IOPAGES) + 1) / sizeof(u_long); i++)
368 *addr++ = ~0;
369 critical_enter();
370 /* Takes care of tss_rsp0. */
371 memcpy(tssp, &common_tss[PCPU_GET(cpuid)],
372 sizeof(struct amd64tss));
373 tssp->tss_iobase = sizeof(*tssp);
374 pcb->pcb_tssp = tssp;
375 tss_sd = PCPU_GET(tss);
376 tss_sd->sd_lobase = (u_long)tssp & 0xffffff;
377 tss_sd->sd_hibase = ((u_long)tssp >> 24) & 0xfffffffffful;
378 tss_sd->sd_type = SDT_SYSTSS;
379 ltr(GSEL(GPROC0_SEL, SEL_KPL));
380 PCPU_SET(tssp, tssp);
381 critical_exit();
382 } else
383 iomap = (char *)&pcb->pcb_tssp[1];
384 for (i = uap->start; i < uap->start + uap->length; i++) {
385 if (uap->enable)
386 iomap[i >> 3] &= ~(1 << (i & 7));
387 else
388 iomap[i >> 3] |= (1 << (i & 7));
389 }
390 return (error);
391 }
392
393 int
394 amd64_get_ioperm(td, uap)
395 struct thread *td;
396 struct i386_ioperm_args *uap;
397 {
398 int i, state;
399 char *iomap;
400
401 if (uap->start >= IOPAGES * PAGE_SIZE * NBBY)
402 return (EINVAL);
403 if (td->td_pcb->pcb_tssp == NULL) {
404 uap->length = 0;
405 goto done;
406 }
407
408 iomap = (char *)&td->td_pcb->pcb_tssp[1];
409
410 i = uap->start;
411 state = (iomap[i >> 3] >> (i & 7)) & 1;
412 uap->enable = !state;
413 uap->length = 1;
414
415 for (i = uap->start + 1; i < IOPAGES * PAGE_SIZE * NBBY; i++) {
416 if (state != ((iomap[i >> 3] >> (i & 7)) & 1))
417 break;
418 uap->length++;
419 }
420
421 done:
422 return (0);
423 }
424
425 /*
426 * Update the GDT entry pointing to the LDT to point to the LDT of the
427 * current process.
428 */
429 void
430 set_user_ldt(struct mdproc *mdp)
431 {
432
433 critical_enter();
434 *PCPU_GET(ldt) = mdp->md_ldt_sd;
435 lldt(GSEL(GUSERLDT_SEL, SEL_KPL));
436 critical_exit();
437 }
438
439 #ifdef notyet
440 #ifdef SMP
441 static void
442 set_user_ldt_rv(struct vmspace *vmsp)
443 {
444 struct thread *td;
445
446 td = curthread;
447 if (vmsp != td->td_proc->p_vmspace)
448 return;
449
450 set_user_ldt(&td->td_proc->p_md);
451 }
452 #endif
453 #endif
454
455 struct proc_ldt *
456 user_ldt_alloc(struct proc *p, int force)
457 {
458 struct proc_ldt *pldt, *new_ldt;
459 struct mdproc *mdp;
460 struct soft_segment_descriptor sldt;
461
462 mtx_assert(&dt_lock, MA_OWNED);
463 mdp = &p->p_md;
464 if (!force && mdp->md_ldt != NULL)
465 return (mdp->md_ldt);
466 mtx_unlock(&dt_lock);
467 new_ldt = malloc(sizeof(struct proc_ldt), M_SUBPROC, M_WAITOK);
468 new_ldt->ldt_base = (caddr_t)kmem_malloc(kernel_arena,
469 max_ldt_segment * sizeof(struct user_segment_descriptor),
470 M_WAITOK | M_ZERO);
471 if (new_ldt->ldt_base == NULL) {
472 FREE(new_ldt, M_SUBPROC);
473 mtx_lock(&dt_lock);
474 return (NULL);
475 }
476 new_ldt->ldt_refcnt = 1;
477 sldt.ssd_base = (uint64_t)new_ldt->ldt_base;
478 sldt.ssd_limit = max_ldt_segment *
479 sizeof(struct user_segment_descriptor) - 1;
480 sldt.ssd_type = SDT_SYSLDT;
481 sldt.ssd_dpl = SEL_KPL;
482 sldt.ssd_p = 1;
483 sldt.ssd_long = 0;
484 sldt.ssd_def32 = 0;
485 sldt.ssd_gran = 0;
486 mtx_lock(&dt_lock);
487 pldt = mdp->md_ldt;
488 if (pldt != NULL && !force) {
489 kmem_free(kernel_arena, (vm_offset_t)new_ldt->ldt_base,
490 max_ldt_segment * sizeof(struct user_segment_descriptor));
491 free(new_ldt, M_SUBPROC);
492 return (pldt);
493 }
494
495 if (pldt != NULL) {
496 bcopy(pldt->ldt_base, new_ldt->ldt_base, max_ldt_segment *
497 sizeof(struct user_segment_descriptor));
498 user_ldt_derefl(pldt);
499 }
500 ssdtosyssd(&sldt, &p->p_md.md_ldt_sd);
501 atomic_store_rel_ptr((volatile uintptr_t *)&mdp->md_ldt,
502 (uintptr_t)new_ldt);
503 if (p == curproc)
504 set_user_ldt(mdp);
505
506 return (mdp->md_ldt);
507 }
508
509 void
510 user_ldt_free(struct thread *td)
511 {
512 struct proc *p = td->td_proc;
513 struct mdproc *mdp = &p->p_md;
514 struct proc_ldt *pldt;
515
516 mtx_assert(&dt_lock, MA_OWNED);
517 if ((pldt = mdp->md_ldt) == NULL) {
518 mtx_unlock(&dt_lock);
519 return;
520 }
521
522 mdp->md_ldt = NULL;
523 bzero(&mdp->md_ldt_sd, sizeof(mdp->md_ldt_sd));
524 if (td == curthread)
525 lldt(GSEL(GNULL_SEL, SEL_KPL));
526 user_ldt_deref(pldt);
527 }
528
529 static void
530 user_ldt_derefl(struct proc_ldt *pldt)
531 {
532
533 if (--pldt->ldt_refcnt == 0) {
534 kmem_free(kernel_arena, (vm_offset_t)pldt->ldt_base,
535 max_ldt_segment * sizeof(struct user_segment_descriptor));
536 free(pldt, M_SUBPROC);
537 }
538 }
539
540 void
541 user_ldt_deref(struct proc_ldt *pldt)
542 {
543
544 mtx_assert(&dt_lock, MA_OWNED);
545 user_ldt_derefl(pldt);
546 mtx_unlock(&dt_lock);
547 }
548
549 /*
550 * Note for the authors of compat layers (linux, etc): copyout() in
551 * the function below is not a problem since it presents data in
552 * arch-specific format (i.e. i386-specific in this case), not in
553 * the OS-specific one.
554 */
555 int
556 amd64_get_ldt(td, uap)
557 struct thread *td;
558 struct i386_ldt_args *uap;
559 {
560 int error = 0;
561 struct proc_ldt *pldt;
562 int num;
563 struct user_segment_descriptor *lp;
564
565 #ifdef DEBUG
566 printf("amd64_get_ldt: start=%d num=%d descs=%p\n",
567 uap->start, uap->num, (void *)uap->descs);
568 #endif
569
570 if ((pldt = td->td_proc->p_md.md_ldt) != NULL) {
571 lp = &((struct user_segment_descriptor *)(pldt->ldt_base))
572 [uap->start];
573 num = min(uap->num, max_ldt_segment);
574 } else
575 return (EINVAL);
576
577 if ((uap->start > (unsigned int)max_ldt_segment) ||
578 ((unsigned int)num > (unsigned int)max_ldt_segment) ||
579 ((unsigned int)(uap->start + num) > (unsigned int)max_ldt_segment))
580 return(EINVAL);
581
582 error = copyout(lp, uap->descs, num *
583 sizeof(struct user_segment_descriptor));
584 if (!error)
585 td->td_retval[0] = num;
586
587 return(error);
588 }
589
590 int
591 amd64_set_ldt(td, uap, descs)
592 struct thread *td;
593 struct i386_ldt_args *uap;
594 struct user_segment_descriptor *descs;
595 {
596 int error = 0;
597 unsigned int largest_ld, i;
598 struct mdproc *mdp = &td->td_proc->p_md;
599 struct proc_ldt *pldt;
600 struct user_segment_descriptor *dp;
601 struct proc *p;
602
603 #ifdef DEBUG
604 printf("amd64_set_ldt: start=%d num=%d descs=%p\n",
605 uap->start, uap->num, (void *)uap->descs);
606 #endif
607
608 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
609 p = td->td_proc;
610 if (descs == NULL) {
611 /* Free descriptors */
612 if (uap->start == 0 && uap->num == 0)
613 uap->num = max_ldt_segment;
614 if (uap->num == 0)
615 return (EINVAL);
616 if ((pldt = mdp->md_ldt) == NULL ||
617 uap->start >= max_ldt_segment)
618 return (0);
619 largest_ld = uap->start + uap->num;
620 if (largest_ld > max_ldt_segment)
621 largest_ld = max_ldt_segment;
622 if (largest_ld < uap->start)
623 return (EINVAL);
624 i = largest_ld - uap->start;
625 mtx_lock(&dt_lock);
626 bzero(&((struct user_segment_descriptor *)(pldt->ldt_base))
627 [uap->start], sizeof(struct user_segment_descriptor) * i);
628 mtx_unlock(&dt_lock);
629 return (0);
630 }
631
632 if (!(uap->start == LDT_AUTO_ALLOC && uap->num == 1)) {
633 /* verify range of descriptors to modify */
634 largest_ld = uap->start + uap->num;
635 if (uap->start >= max_ldt_segment ||
636 largest_ld > max_ldt_segment ||
637 largest_ld < uap->start)
638 return (EINVAL);
639 }
640
641 /* Check descriptors for access violations */
642 for (i = 0; i < uap->num; i++) {
643 dp = &descs[i];
644
645 switch (dp->sd_type) {
646 case SDT_SYSNULL: /* system null */
647 dp->sd_p = 0;
648 break;
649 case SDT_SYS286TSS:
650 case SDT_SYSLDT:
651 case SDT_SYS286BSY:
652 case SDT_SYS286CGT:
653 case SDT_SYSTASKGT:
654 case SDT_SYS286IGT:
655 case SDT_SYS286TGT:
656 case SDT_SYSNULL2:
657 case SDT_SYSTSS:
658 case SDT_SYSNULL3:
659 case SDT_SYSBSY:
660 case SDT_SYSCGT:
661 case SDT_SYSNULL4:
662 case SDT_SYSIGT:
663 case SDT_SYSTGT:
664 /* I can't think of any reason to allow a user proc
665 * to create a segment of these types. They are
666 * for OS use only.
667 */
668 return (EACCES);
669 /*NOTREACHED*/
670
671 /* memory segment types */
672 case SDT_MEMEC: /* memory execute only conforming */
673 case SDT_MEMEAC: /* memory execute only accessed conforming */
674 case SDT_MEMERC: /* memory execute read conforming */
675 case SDT_MEMERAC: /* memory execute read accessed conforming */
676 /* Must be "present" if executable and conforming. */
677 if (dp->sd_p == 0)
678 return (EACCES);
679 break;
680 case SDT_MEMRO: /* memory read only */
681 case SDT_MEMROA: /* memory read only accessed */
682 case SDT_MEMRW: /* memory read write */
683 case SDT_MEMRWA: /* memory read write accessed */
684 case SDT_MEMROD: /* memory read only expand dwn limit */
685 case SDT_MEMRODA: /* memory read only expand dwn lim accessed */
686 case SDT_MEMRWD: /* memory read write expand dwn limit */
687 case SDT_MEMRWDA: /* memory read write expand dwn lim acessed */
688 case SDT_MEME: /* memory execute only */
689 case SDT_MEMEA: /* memory execute only accessed */
690 case SDT_MEMER: /* memory execute read */
691 case SDT_MEMERA: /* memory execute read accessed */
692 break;
693 default:
694 return(EINVAL);
695 /*NOTREACHED*/
696 }
697
698 /* Only user (ring-3) descriptors may be present. */
699 if ((dp->sd_p != 0) && (dp->sd_dpl != SEL_UPL))
700 return (EACCES);
701 }
702
703 if (uap->start == LDT_AUTO_ALLOC && uap->num == 1) {
704 /* Allocate a free slot */
705 mtx_lock(&dt_lock);
706 pldt = user_ldt_alloc(p, 0);
707 if (pldt == NULL) {
708 mtx_unlock(&dt_lock);
709 return (ENOMEM);
710 }
711
712 /*
713 * start scanning a bit up to leave room for NVidia and
714 * Wine, which still user the "Blat" method of allocation.
715 */
716 i = 16;
717 dp = &((struct user_segment_descriptor *)(pldt->ldt_base))[i];
718 for (; i < max_ldt_segment; ++i, ++dp) {
719 if (dp->sd_type == SDT_SYSNULL)
720 break;
721 }
722 if (i >= max_ldt_segment) {
723 mtx_unlock(&dt_lock);
724 return (ENOSPC);
725 }
726 uap->start = i;
727 error = amd64_set_ldt_data(td, i, 1, descs);
728 mtx_unlock(&dt_lock);
729 } else {
730 largest_ld = uap->start + uap->num;
731 if (largest_ld > max_ldt_segment)
732 return (EINVAL);
733 mtx_lock(&dt_lock);
734 if (user_ldt_alloc(p, 0) != NULL) {
735 error = amd64_set_ldt_data(td, uap->start, uap->num,
736 descs);
737 }
738 mtx_unlock(&dt_lock);
739 }
740 if (error == 0)
741 td->td_retval[0] = uap->start;
742 return (error);
743 }
744
745 int
746 amd64_set_ldt_data(struct thread *td, int start, int num,
747 struct user_segment_descriptor *descs)
748 {
749 struct mdproc *mdp = &td->td_proc->p_md;
750 struct proc_ldt *pldt = mdp->md_ldt;
751
752 mtx_assert(&dt_lock, MA_OWNED);
753
754 /* Fill in range */
755 bcopy(descs,
756 &((struct user_segment_descriptor *)(pldt->ldt_base))[start],
757 num * sizeof(struct user_segment_descriptor));
758 return (0);
759 }
Cache object: 064405e4203815c729b2e489ca4710fd
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