1 /*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 1982, 1986 The Regents of the University of California.
5 * Copyright (c) 1989, 1990 William Jolitz
6 * Copyright (c) 1994 John Dyson
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to Berkeley by
10 * the Systems Programming Group of the University of Utah Computer
11 * Science Department, and William Jolitz.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. All advertising materials mentioning features or use of this software
22 * must display the following acknowledgement:
23 * This product includes software developed by the University of
24 * California, Berkeley and its contributors.
25 * 4. Neither the name of the University nor the names of its contributors
26 * may be used to endorse or promote products derived from this software
27 * without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 *
41 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
42 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
43 */
44
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47
48 #include "opt_isa.h"
49 #include "opt_cpu.h"
50
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/bio.h>
54 #include <sys/buf.h>
55 #include <sys/kernel.h>
56 #include <sys/ktr.h>
57 #include <sys/lock.h>
58 #include <sys/malloc.h>
59 #include <sys/mbuf.h>
60 #include <sys/mutex.h>
61 #include <sys/priv.h>
62 #include <sys/proc.h>
63 #include <sys/procctl.h>
64 #include <sys/smp.h>
65 #include <sys/sysctl.h>
66 #include <sys/sysent.h>
67 #include <sys/unistd.h>
68 #include <sys/vnode.h>
69 #include <sys/vmmeter.h>
70 #include <sys/wait.h>
71
72 #include <machine/cpu.h>
73 #include <machine/md_var.h>
74 #include <machine/pcb.h>
75 #include <machine/smp.h>
76 #include <machine/specialreg.h>
77 #include <machine/tss.h>
78
79 #include <vm/vm.h>
80 #include <vm/vm_extern.h>
81 #include <vm/vm_kern.h>
82 #include <vm/vm_page.h>
83 #include <vm/vm_map.h>
84 #include <vm/vm_param.h>
85
86 _Static_assert(OFFSETOF_MONITORBUF == offsetof(struct pcpu, pc_monitorbuf),
87 "OFFSETOF_MONITORBUF does not correspond with offset of pc_monitorbuf.");
88
89 void
set_top_of_stack_td(struct thread * td)90 set_top_of_stack_td(struct thread *td)
91 {
92 td->td_md.md_stack_base = td->td_kstack +
93 td->td_kstack_pages * PAGE_SIZE -
94 roundup2(cpu_max_ext_state_size, XSAVE_AREA_ALIGN);
95 }
96
97 struct savefpu *
get_pcb_user_save_td(struct thread * td)98 get_pcb_user_save_td(struct thread *td)
99 {
100 vm_offset_t p;
101
102 p = td->td_md.md_stack_base;
103 KASSERT((p % XSAVE_AREA_ALIGN) == 0,
104 ("Unaligned pcb_user_save area ptr %#lx td %p", p, td));
105 return ((struct savefpu *)p);
106 }
107
108 struct pcb *
get_pcb_td(struct thread * td)109 get_pcb_td(struct thread *td)
110 {
111
112 return (&td->td_md.md_pcb);
113 }
114
115 struct savefpu *
get_pcb_user_save_pcb(struct pcb * pcb)116 get_pcb_user_save_pcb(struct pcb *pcb)
117 {
118 struct thread *td;
119
120 td = __containerof(pcb, struct thread, td_md.md_pcb);
121 return (get_pcb_user_save_td(td));
122 }
123
124 void *
alloc_fpusave(int flags)125 alloc_fpusave(int flags)
126 {
127 void *res;
128 struct savefpu_ymm *sf;
129
130 res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags);
131 if (use_xsave) {
132 sf = (struct savefpu_ymm *)res;
133 bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd));
134 sf->sv_xstate.sx_hd.xstate_bv = xsave_mask;
135 }
136 return (res);
137 }
138
139 /*
140 * Finish a fork operation, with process p2 nearly set up.
141 * Copy and update the pcb, set up the stack so that the child
142 * ready to run and return to user mode.
143 */
144 void
cpu_fork(struct thread * td1,struct proc * p2,struct thread * td2,int flags)145 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
146 {
147 struct proc *p1;
148 struct pcb *pcb2;
149 struct mdproc *mdp1, *mdp2;
150 struct proc_ldt *pldt;
151
152 p1 = td1->td_proc;
153 if ((flags & RFPROC) == 0) {
154 if ((flags & RFMEM) == 0) {
155 /* unshare user LDT */
156 mdp1 = &p1->p_md;
157 mtx_lock(&dt_lock);
158 if ((pldt = mdp1->md_ldt) != NULL &&
159 pldt->ldt_refcnt > 1 &&
160 user_ldt_alloc(p1, 1) == NULL)
161 panic("could not copy LDT");
162 mtx_unlock(&dt_lock);
163 }
164 return;
165 }
166
167 /* Ensure that td1's pcb is up to date. */
168 fpuexit(td1);
169 update_pcb_bases(td1->td_pcb);
170
171 /* Point the stack and pcb to the actual location */
172 set_top_of_stack_td(td2);
173 td2->td_pcb = pcb2 = get_pcb_td(td2);
174
175 /* Copy td1's pcb */
176 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
177
178 /* Properly initialize pcb_save */
179 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
180 bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2),
181 cpu_max_ext_state_size);
182
183 /* Point mdproc and then copy over td1's contents */
184 mdp2 = &p2->p_md;
185 bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
186
187 /*
188 * Create a new fresh stack for the new process.
189 * Copy the trap frame for the return to user mode as if from a
190 * syscall. This copies most of the user mode register values.
191 */
192 td2->td_frame = (struct trapframe *)td2->td_md.md_stack_base - 1;
193 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
194
195 td2->td_frame->tf_rax = 0; /* Child returns zero */
196 td2->td_frame->tf_rflags &= ~PSL_C; /* success */
197 td2->td_frame->tf_rdx = 1;
198
199 /*
200 * If the parent process has the trap bit set (i.e. a debugger
201 * had single stepped the process to the system call), we need
202 * to clear the trap flag from the new frame.
203 */
204 td2->td_frame->tf_rflags &= ~PSL_T;
205
206 /*
207 * Set registers for trampoline to user mode. Leave space for the
208 * return address on stack. These are the kernel mode register values.
209 */
210 pcb2->pcb_r12 = (register_t)fork_return; /* fork_trampoline argument */
211 pcb2->pcb_rbp = 0;
212 pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *);
213 pcb2->pcb_rbx = (register_t)td2; /* fork_trampoline argument */
214 pcb2->pcb_rip = (register_t)fork_trampoline;
215 /*-
216 * pcb2->pcb_dr*: cloned above.
217 * pcb2->pcb_savefpu: cloned above.
218 * pcb2->pcb_flags: cloned above.
219 * pcb2->pcb_onfault: cloned above (always NULL here?).
220 * pcb2->pcb_[fg]sbase: cloned above
221 */
222
223 /* Setup to release spin count in fork_exit(). */
224 td2->td_md.md_spinlock_count = 1;
225 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
226 pmap_thread_init_invl_gen(td2);
227
228 /* As an i386, do not copy io permission bitmap. */
229 pcb2->pcb_tssp = NULL;
230
231 /* New segment registers. */
232 set_pcb_flags_raw(pcb2, PCB_FULL_IRET);
233
234 /* Copy the LDT, if necessary. */
235 mdp1 = &td1->td_proc->p_md;
236 mdp2 = &p2->p_md;
237 if (mdp1->md_ldt == NULL) {
238 mdp2->md_ldt = NULL;
239 return;
240 }
241 mtx_lock(&dt_lock);
242 if (mdp1->md_ldt != NULL) {
243 if (flags & RFMEM) {
244 mdp1->md_ldt->ldt_refcnt++;
245 mdp2->md_ldt = mdp1->md_ldt;
246 bcopy(&mdp1->md_ldt_sd, &mdp2->md_ldt_sd, sizeof(struct
247 system_segment_descriptor));
248 } else {
249 mdp2->md_ldt = NULL;
250 mdp2->md_ldt = user_ldt_alloc(p2, 0);
251 if (mdp2->md_ldt == NULL)
252 panic("could not copy LDT");
253 amd64_set_ldt_data(td2, 0, max_ldt_segment,
254 (struct user_segment_descriptor *)
255 mdp1->md_ldt->ldt_base);
256 }
257 } else
258 mdp2->md_ldt = NULL;
259 mtx_unlock(&dt_lock);
260
261 /*
262 * Now, cpu_switch() can schedule the new process.
263 * pcb_rsp is loaded pointing to the cpu_switch() stack frame
264 * containing the return address when exiting cpu_switch.
265 * This will normally be to fork_trampoline(), which will have
266 * %ebx loaded with the new proc's pointer. fork_trampoline()
267 * will set up a stack to call fork_return(p, frame); to complete
268 * the return to user-mode.
269 */
270 }
271
272 /*
273 * Intercept the return address from a freshly forked process that has NOT
274 * been scheduled yet.
275 *
276 * This is needed to make kernel threads stay in kernel mode.
277 */
278 void
cpu_fork_kthread_handler(struct thread * td,void (* func)(void *),void * arg)279 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg)
280 {
281 /*
282 * Note that the trap frame follows the args, so the function
283 * is really called like this: func(arg, frame);
284 */
285 td->td_pcb->pcb_r12 = (long) func; /* function */
286 td->td_pcb->pcb_rbx = (long) arg; /* first arg */
287 }
288
289 void
cpu_exit(struct thread * td)290 cpu_exit(struct thread *td)
291 {
292
293 /*
294 * If this process has a custom LDT, release it.
295 */
296 if (td->td_proc->p_md.md_ldt != NULL)
297 user_ldt_free(td);
298 }
299
300 void
cpu_thread_exit(struct thread * td)301 cpu_thread_exit(struct thread *td)
302 {
303 struct pcb *pcb;
304
305 critical_enter();
306 if (td == PCPU_GET(fpcurthread))
307 fpudrop();
308 critical_exit();
309
310 pcb = td->td_pcb;
311
312 /* Disable any hardware breakpoints. */
313 if (pcb->pcb_flags & PCB_DBREGS) {
314 reset_dbregs();
315 clear_pcb_flags(pcb, PCB_DBREGS);
316 }
317 }
318
319 void
cpu_thread_clean(struct thread * td)320 cpu_thread_clean(struct thread *td)
321 {
322 struct pcb *pcb;
323
324 pcb = td->td_pcb;
325
326 /*
327 * Clean TSS/iomap
328 */
329 if (pcb->pcb_tssp != NULL) {
330 pmap_pti_remove_kva((vm_offset_t)pcb->pcb_tssp,
331 (vm_offset_t)pcb->pcb_tssp + ctob(IOPAGES + 1));
332 kmem_free((vm_offset_t)pcb->pcb_tssp, ctob(IOPAGES + 1));
333 pcb->pcb_tssp = NULL;
334 }
335 }
336
337 void
cpu_thread_swapin(struct thread * td)338 cpu_thread_swapin(struct thread *td)
339 {
340 }
341
342 void
cpu_thread_swapout(struct thread * td)343 cpu_thread_swapout(struct thread *td)
344 {
345 }
346
347 void
cpu_thread_alloc(struct thread * td)348 cpu_thread_alloc(struct thread *td)
349 {
350 struct pcb *pcb;
351 struct xstate_hdr *xhdr;
352
353 set_top_of_stack_td(td);
354 td->td_pcb = pcb = get_pcb_td(td);
355 td->td_frame = (struct trapframe *)td->td_md.md_stack_base - 1;
356 pcb->pcb_save = get_pcb_user_save_pcb(pcb);
357 if (use_xsave) {
358 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1);
359 bzero(xhdr, sizeof(*xhdr));
360 xhdr->xstate_bv = xsave_mask;
361 }
362 }
363
364 void
cpu_thread_free(struct thread * td)365 cpu_thread_free(struct thread *td)
366 {
367
368 cpu_thread_clean(td);
369 }
370
371 bool
cpu_exec_vmspace_reuse(struct proc * p,vm_map_t map)372 cpu_exec_vmspace_reuse(struct proc *p, vm_map_t map)
373 {
374
375 return (((curproc->p_md.md_flags & P_MD_KPTI) != 0) ==
376 (vm_map_pmap(map)->pm_ucr3 != PMAP_NO_CR3));
377 }
378
379 static void
cpu_procctl_kpti_ctl(struct proc * p,int val)380 cpu_procctl_kpti_ctl(struct proc *p, int val)
381 {
382
383 if (pti && val == PROC_KPTI_CTL_ENABLE_ON_EXEC)
384 p->p_md.md_flags |= P_MD_KPTI;
385 if (val == PROC_KPTI_CTL_DISABLE_ON_EXEC)
386 p->p_md.md_flags &= ~P_MD_KPTI;
387 }
388
389 static void
cpu_procctl_kpti_status(struct proc * p,int * val)390 cpu_procctl_kpti_status(struct proc *p, int *val)
391 {
392 *val = (p->p_md.md_flags & P_MD_KPTI) != 0 ?
393 PROC_KPTI_CTL_ENABLE_ON_EXEC:
394 PROC_KPTI_CTL_DISABLE_ON_EXEC;
395 if (vmspace_pmap(p->p_vmspace)->pm_ucr3 != PMAP_NO_CR3)
396 *val |= PROC_KPTI_STATUS_ACTIVE;
397 }
398
399 static int
cpu_procctl_la_ctl(struct proc * p,int val)400 cpu_procctl_la_ctl(struct proc *p, int val)
401 {
402 int error;
403
404 error = 0;
405 switch (val) {
406 case PROC_LA_CTL_LA48_ON_EXEC:
407 p->p_md.md_flags |= P_MD_LA48;
408 p->p_md.md_flags &= ~P_MD_LA57;
409 break;
410 case PROC_LA_CTL_LA57_ON_EXEC:
411 if (la57) {
412 p->p_md.md_flags &= ~P_MD_LA48;
413 p->p_md.md_flags |= P_MD_LA57;
414 } else {
415 error = ENOTSUP;
416 }
417 break;
418 case PROC_LA_CTL_DEFAULT_ON_EXEC:
419 p->p_md.md_flags &= ~(P_MD_LA48 | P_MD_LA57);
420 break;
421 }
422 return (error);
423 }
424
425 static void
cpu_procctl_la_status(struct proc * p,int * val)426 cpu_procctl_la_status(struct proc *p, int *val)
427 {
428 int res;
429
430 if ((p->p_md.md_flags & P_MD_LA48) != 0)
431 res = PROC_LA_CTL_LA48_ON_EXEC;
432 else if ((p->p_md.md_flags & P_MD_LA57) != 0)
433 res = PROC_LA_CTL_LA57_ON_EXEC;
434 else
435 res = PROC_LA_CTL_DEFAULT_ON_EXEC;
436 if (p->p_sysent->sv_maxuser == VM_MAXUSER_ADDRESS_LA48)
437 res |= PROC_LA_STATUS_LA48;
438 else
439 res |= PROC_LA_STATUS_LA57;
440 *val = res;
441 }
442
443 int
cpu_procctl(struct thread * td,int idtype,id_t id,int com,void * data)444 cpu_procctl(struct thread *td, int idtype, id_t id, int com, void *data)
445 {
446 struct proc *p;
447 int error, val;
448
449 switch (com) {
450 case PROC_KPTI_CTL:
451 case PROC_KPTI_STATUS:
452 case PROC_LA_CTL:
453 case PROC_LA_STATUS:
454 if (idtype != P_PID) {
455 error = EINVAL;
456 break;
457 }
458 if (com == PROC_KPTI_CTL) {
459 /* sad but true and not a joke */
460 error = priv_check(td, PRIV_IO);
461 if (error != 0)
462 break;
463 }
464 if (com == PROC_KPTI_CTL || com == PROC_LA_CTL) {
465 error = copyin(data, &val, sizeof(val));
466 if (error != 0)
467 break;
468 }
469 if (com == PROC_KPTI_CTL &&
470 val != PROC_KPTI_CTL_ENABLE_ON_EXEC &&
471 val != PROC_KPTI_CTL_DISABLE_ON_EXEC) {
472 error = EINVAL;
473 break;
474 }
475 if (com == PROC_LA_CTL &&
476 val != PROC_LA_CTL_LA48_ON_EXEC &&
477 val != PROC_LA_CTL_LA57_ON_EXEC &&
478 val != PROC_LA_CTL_DEFAULT_ON_EXEC) {
479 error = EINVAL;
480 break;
481 }
482 error = pget(id, PGET_CANSEE | PGET_NOTWEXIT | PGET_NOTID, &p);
483 if (error != 0)
484 break;
485 switch (com) {
486 case PROC_KPTI_CTL:
487 cpu_procctl_kpti_ctl(p, val);
488 break;
489 case PROC_KPTI_STATUS:
490 cpu_procctl_kpti_status(p, &val);
491 break;
492 case PROC_LA_CTL:
493 error = cpu_procctl_la_ctl(p, val);
494 break;
495 case PROC_LA_STATUS:
496 cpu_procctl_la_status(p, &val);
497 break;
498 }
499 PROC_UNLOCK(p);
500 if (com == PROC_KPTI_STATUS || com == PROC_LA_STATUS)
501 error = copyout(&val, data, sizeof(val));
502 break;
503 default:
504 error = EINVAL;
505 break;
506 }
507 return (error);
508 }
509
510 void
cpu_set_syscall_retval(struct thread * td,int error)511 cpu_set_syscall_retval(struct thread *td, int error)
512 {
513 struct trapframe *frame;
514
515 frame = td->td_frame;
516 if (__predict_true(error == 0)) {
517 frame->tf_rax = td->td_retval[0];
518 frame->tf_rdx = td->td_retval[1];
519 frame->tf_rflags &= ~PSL_C;
520 return;
521 }
522
523 switch (error) {
524 case ERESTART:
525 /*
526 * Reconstruct pc, we know that 'syscall' is 2 bytes,
527 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes.
528 * We saved this in tf_err.
529 * %r10 (which was holding the value of %rcx) is restored
530 * for the next iteration.
531 * %r10 restore is only required for freebsd/amd64 processes,
532 * but shall be innocent for any ia32 ABI.
533 *
534 * Require full context restore to get the arguments
535 * in the registers reloaded at return to usermode.
536 */
537 frame->tf_rip -= frame->tf_err;
538 frame->tf_r10 = frame->tf_rcx;
539 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
540 break;
541
542 case EJUSTRETURN:
543 break;
544
545 default:
546 frame->tf_rax = error;
547 frame->tf_rflags |= PSL_C;
548 break;
549 }
550 }
551
552 /*
553 * Initialize machine state, mostly pcb and trap frame for a new
554 * thread, about to return to userspace. Put enough state in the new
555 * thread's PCB to get it to go back to the fork_return(), which
556 * finalizes the thread state and handles peculiarities of the first
557 * return to userspace for the new thread.
558 */
559 void
cpu_copy_thread(struct thread * td,struct thread * td0)560 cpu_copy_thread(struct thread *td, struct thread *td0)
561 {
562 struct pcb *pcb2;
563
564 pcb2 = td->td_pcb;
565
566 /*
567 * Copy the upcall pcb. This loads kernel regs.
568 * Those not loaded individually below get their default
569 * values here.
570 */
571 update_pcb_bases(td0->td_pcb);
572 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
573 clear_pcb_flags(pcb2, PCB_FPUINITDONE | PCB_USERFPUINITDONE |
574 PCB_KERNFPU);
575 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
576 bcopy(get_pcb_user_save_td(td0), pcb2->pcb_save,
577 cpu_max_ext_state_size);
578 set_pcb_flags_raw(pcb2, PCB_FULL_IRET);
579
580 /*
581 * Create a new fresh stack for the new thread.
582 */
583 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
584
585 /* If the current thread has the trap bit set (i.e. a debugger had
586 * single stepped the process to the system call), we need to clear
587 * the trap flag from the new frame. Otherwise, the new thread will
588 * receive a (likely unexpected) SIGTRAP when it executes the first
589 * instruction after returning to userland.
590 */
591 td->td_frame->tf_rflags &= ~PSL_T;
592
593 /*
594 * Set registers for trampoline to user mode. Leave space for the
595 * return address on stack. These are the kernel mode register values.
596 */
597 pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */
598 pcb2->pcb_rbp = 0;
599 pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */
600 pcb2->pcb_rbx = (register_t)td; /* trampoline arg */
601 pcb2->pcb_rip = (register_t)fork_trampoline;
602 /*
603 * If we didn't copy the pcb, we'd need to do the following registers:
604 * pcb2->pcb_dr*: cloned above.
605 * pcb2->pcb_savefpu: cloned above.
606 * pcb2->pcb_onfault: cloned above (always NULL here?).
607 * pcb2->pcb_[fg]sbase: cloned above
608 */
609
610 /* Setup to release spin count in fork_exit(). */
611 td->td_md.md_spinlock_count = 1;
612 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
613 pmap_thread_init_invl_gen(td);
614 }
615
616 /*
617 * Set that machine state for performing an upcall that starts
618 * the entry function with the given argument.
619 */
620 void
cpu_set_upcall(struct thread * td,void (* entry)(void *),void * arg,stack_t * stack)621 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg,
622 stack_t *stack)
623 {
624
625 /*
626 * Do any extra cleaning that needs to be done.
627 * The thread may have optional components
628 * that are not present in a fresh thread.
629 * This may be a recycled thread so make it look
630 * as though it's newly allocated.
631 */
632 cpu_thread_clean(td);
633
634 #ifdef COMPAT_FREEBSD32
635 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
636 /*
637 * Set the trap frame to point at the beginning of the entry
638 * function.
639 */
640 td->td_frame->tf_rbp = 0;
641 td->td_frame->tf_rsp =
642 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
643 td->td_frame->tf_rip = (uintptr_t)entry;
644
645 /* Return address sentinel value to stop stack unwinding. */
646 suword32((void *)td->td_frame->tf_rsp, 0);
647
648 /* Pass the argument to the entry point. */
649 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)),
650 (uint32_t)(uintptr_t)arg);
651
652 return;
653 }
654 #endif
655
656 /*
657 * Set the trap frame to point at the beginning of the uts
658 * function.
659 */
660 td->td_frame->tf_rbp = 0;
661 td->td_frame->tf_rsp =
662 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f;
663 td->td_frame->tf_rsp -= 8;
664 td->td_frame->tf_rip = (register_t)entry;
665 td->td_frame->tf_ds = _udatasel;
666 td->td_frame->tf_es = _udatasel;
667 td->td_frame->tf_fs = _ufssel;
668 td->td_frame->tf_gs = _ugssel;
669 td->td_frame->tf_flags = TF_HASSEGS;
670
671 /* Return address sentinel value to stop stack unwinding. */
672 suword((void *)td->td_frame->tf_rsp, 0);
673
674 /* Pass the argument to the entry point. */
675 td->td_frame->tf_rdi = (register_t)arg;
676 }
677
678 int
cpu_set_user_tls(struct thread * td,void * tls_base)679 cpu_set_user_tls(struct thread *td, void *tls_base)
680 {
681 struct pcb *pcb;
682
683 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS)
684 return (EINVAL);
685
686 pcb = td->td_pcb;
687 set_pcb_flags(pcb, PCB_FULL_IRET);
688 #ifdef COMPAT_FREEBSD32
689 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
690 pcb->pcb_gsbase = (register_t)tls_base;
691 return (0);
692 }
693 #endif
694 pcb->pcb_fsbase = (register_t)tls_base;
695 return (0);
696 }
697
698 /*
699 * Software interrupt handler for queued VM system processing.
700 */
701 void
swi_vm(void * dummy)702 swi_vm(void *dummy)
703 {
704 if (busdma_swi_pending != 0)
705 busdma_swi();
706 }
707
708 /*
709 * Tell whether this address is in some physical memory region.
710 * Currently used by the kernel coredump code in order to avoid
711 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
712 * or other unpredictable behaviour.
713 */
714
715 int
is_physical_memory(vm_paddr_t addr)716 is_physical_memory(vm_paddr_t addr)
717 {
718
719 #ifdef DEV_ISA
720 /* The ISA ``memory hole''. */
721 if (addr >= 0xa0000 && addr < 0x100000)
722 return 0;
723 #endif
724
725 /*
726 * stuff other tests for known memory-mapped devices (PCI?)
727 * here
728 */
729
730 return 1;
731 }
732