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
89void
90set_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
97struct savefpu *
98get_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
108struct pcb *
109get_pcb_td(struct thread *td)
110{
111
112	return (&td->td_md.md_pcb);
113}
114
115struct savefpu *
116get_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
124void *
125alloc_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 * Common code shared between cpu_fork() and cpu_copy_thread() for
141 * initializing a thread.
142 */
143static void
144copy_thread(struct thread *td1, struct thread *td2)
145{
146	struct pcb *pcb2;
147
148	pcb2 = td2->td_pcb;
149
150	/* Ensure that td1's pcb is up to date for user threads. */
151	if ((td2->td_pflags & TDP_KTHREAD) == 0) {
152		MPASS(td1 == curthread);
153		fpuexit(td1);
154		update_pcb_bases(td1->td_pcb);
155	}
156
157	/* Copy td1's pcb */
158	bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
159
160	/* Properly initialize pcb_save */
161	pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
162
163	/* Kernel threads start with clean FPU and segment bases. */
164	if ((td2->td_pflags & TDP_KTHREAD) != 0) {
165		pcb2->pcb_fsbase = 0;
166		pcb2->pcb_gsbase = 0;
167		clear_pcb_flags(pcb2, PCB_FPUINITDONE | PCB_USERFPUINITDONE |
168		    PCB_KERNFPU | PCB_KERNFPU_THR);
169	} else {
170		MPASS((pcb2->pcb_flags & (PCB_KERNFPU | PCB_KERNFPU_THR)) == 0);
171		bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2),
172		    cpu_max_ext_state_size);
173	}
174
175	/*
176	 * Set registers for trampoline to user mode.  Leave space for the
177	 * return address on stack.  These are the kernel mode register values.
178	 */
179	pcb2->pcb_r12 = (register_t)fork_return;	/* fork_trampoline argument */
180	pcb2->pcb_rbp = 0;
181	pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *);
182	pcb2->pcb_rbx = (register_t)td2;		/* fork_trampoline argument */
183	pcb2->pcb_rip = (register_t)fork_trampoline;
184	/*-
185	 * pcb2->pcb_dr*:	cloned above.
186	 * pcb2->pcb_savefpu:	cloned above.
187	 * pcb2->pcb_flags:	cloned above.
188	 * pcb2->pcb_onfault:	cloned above (always NULL here?).
189	 * pcb2->pcb_[fg]sbase:	cloned above
190	 */
191
192	pcb2->pcb_tssp = NULL;
193
194	/* Setup to release spin count in fork_exit(). */
195	td2->td_md.md_spinlock_count = 1;
196	td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
197	pmap_thread_init_invl_gen(td2);
198}
199
200/*
201 * Finish a fork operation, with process p2 nearly set up.
202 * Copy and update the pcb, set up the stack so that the child
203 * ready to run and return to user mode.
204 */
205void
206cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
207{
208	struct proc *p1;
209	struct pcb *pcb2;
210	struct mdproc *mdp1, *mdp2;
211	struct proc_ldt *pldt;
212
213	p1 = td1->td_proc;
214	if ((flags & RFPROC) == 0) {
215		if ((flags & RFMEM) == 0) {
216			/* unshare user LDT */
217			mdp1 = &p1->p_md;
218			mtx_lock(&dt_lock);
219			if ((pldt = mdp1->md_ldt) != NULL &&
220			    pldt->ldt_refcnt > 1 &&
221			    user_ldt_alloc(p1, 1) == NULL)
222				panic("could not copy LDT");
223			mtx_unlock(&dt_lock);
224		}
225		return;
226	}
227
228	/* Point the stack and pcb to the actual location */
229	set_top_of_stack_td(td2);
230	td2->td_pcb = pcb2 = get_pcb_td(td2);
231
232	copy_thread(td1, td2);
233
234	/* Reset debug registers in the new process */
235	x86_clear_dbregs(pcb2);
236
237	/* Point mdproc and then copy over p1's contents */
238	mdp2 = &p2->p_md;
239	bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
240
241	/*
242	 * Copy the trap frame for the return to user mode as if from a
243	 * syscall.  This copies most of the user mode register values.
244	 */
245	td2->td_frame = (struct trapframe *)td2->td_md.md_stack_base - 1;
246	bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
247
248	td2->td_frame->tf_rax = 0;		/* Child returns zero */
249	td2->td_frame->tf_rflags &= ~PSL_C;	/* success */
250	td2->td_frame->tf_rdx = 1;
251
252	/*
253	 * If the parent process has the trap bit set (i.e. a debugger
254	 * had single stepped the process to the system call), we need
255	 * to clear the trap flag from the new frame.
256	 */
257	td2->td_frame->tf_rflags &= ~PSL_T;
258
259	/* As on i386, do not copy io permission bitmap. */
260	pcb2->pcb_tssp = NULL;
261
262	/* New segment registers. */
263	set_pcb_flags_raw(pcb2, PCB_FULL_IRET);
264
265	/* Copy the LDT, if necessary. */
266	mdp1 = &td1->td_proc->p_md;
267	mdp2 = &p2->p_md;
268	if (mdp1->md_ldt == NULL) {
269		mdp2->md_ldt = NULL;
270		return;
271	}
272	mtx_lock(&dt_lock);
273	if (mdp1->md_ldt != NULL) {
274		if (flags & RFMEM) {
275			mdp1->md_ldt->ldt_refcnt++;
276			mdp2->md_ldt = mdp1->md_ldt;
277			bcopy(&mdp1->md_ldt_sd, &mdp2->md_ldt_sd, sizeof(struct
278			    system_segment_descriptor));
279		} else {
280			mdp2->md_ldt = NULL;
281			mdp2->md_ldt = user_ldt_alloc(p2, 0);
282			if (mdp2->md_ldt == NULL)
283				panic("could not copy LDT");
284			amd64_set_ldt_data(td2, 0, max_ldt_segment,
285			    (struct user_segment_descriptor *)
286			    mdp1->md_ldt->ldt_base);
287		}
288	} else
289		mdp2->md_ldt = NULL;
290	mtx_unlock(&dt_lock);
291
292	/*
293	 * Now, cpu_switch() can schedule the new process.
294	 * pcb_rsp is loaded pointing to the cpu_switch() stack frame
295	 * containing the return address when exiting cpu_switch.
296	 * This will normally be to fork_trampoline(), which will have
297	 * %rbx loaded with the new proc's pointer.  fork_trampoline()
298	 * will set up a stack to call fork_return(p, frame); to complete
299	 * the return to user-mode.
300	 */
301}
302
303/*
304 * Intercept the return address from a freshly forked process that has NOT
305 * been scheduled yet.
306 *
307 * This is needed to make kernel threads stay in kernel mode.
308 */
309void
310cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg)
311{
312	/*
313	 * Note that the trap frame follows the args, so the function
314	 * is really called like this:  func(arg, frame);
315	 */
316	td->td_pcb->pcb_r12 = (long) func;	/* function */
317	td->td_pcb->pcb_rbx = (long) arg;	/* first arg */
318}
319
320void
321cpu_exit(struct thread *td)
322{
323
324	/*
325	 * If this process has a custom LDT, release it.
326	 */
327	if (td->td_proc->p_md.md_ldt != NULL)
328		user_ldt_free(td);
329}
330
331void
332cpu_thread_exit(struct thread *td)
333{
334	struct pcb *pcb;
335
336	critical_enter();
337	if (td == PCPU_GET(fpcurthread))
338		fpudrop();
339	critical_exit();
340
341	pcb = td->td_pcb;
342
343	/* Disable any hardware breakpoints. */
344	if (pcb->pcb_flags & PCB_DBREGS) {
345		reset_dbregs();
346		clear_pcb_flags(pcb, PCB_DBREGS);
347	}
348}
349
350void
351cpu_thread_clean(struct thread *td)
352{
353	struct pcb *pcb;
354
355	pcb = td->td_pcb;
356
357	/*
358	 * Clean TSS/iomap
359	 */
360	if (pcb->pcb_tssp != NULL) {
361		pmap_pti_remove_kva((vm_offset_t)pcb->pcb_tssp,
362		    (vm_offset_t)pcb->pcb_tssp + ctob(IOPAGES + 1));
363		kmem_free((vm_offset_t)pcb->pcb_tssp, ctob(IOPAGES + 1));
364		pcb->pcb_tssp = NULL;
365	}
366}
367
368void
369cpu_thread_swapin(struct thread *td)
370{
371}
372
373void
374cpu_thread_swapout(struct thread *td)
375{
376}
377
378void
379cpu_thread_alloc(struct thread *td)
380{
381	struct pcb *pcb;
382	struct xstate_hdr *xhdr;
383
384	set_top_of_stack_td(td);
385	td->td_pcb = pcb = get_pcb_td(td);
386	td->td_frame = (struct trapframe *)td->td_md.md_stack_base - 1;
387	pcb->pcb_save = get_pcb_user_save_pcb(pcb);
388	if (use_xsave) {
389		xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1);
390		bzero(xhdr, sizeof(*xhdr));
391		xhdr->xstate_bv = xsave_mask;
392	}
393}
394
395void
396cpu_thread_free(struct thread *td)
397{
398
399	cpu_thread_clean(td);
400}
401
402bool
403cpu_exec_vmspace_reuse(struct proc *p, vm_map_t map)
404{
405
406	return (((curproc->p_md.md_flags & P_MD_KPTI) != 0) ==
407	    (vm_map_pmap(map)->pm_ucr3 != PMAP_NO_CR3));
408}
409
410static void
411cpu_procctl_kpti_ctl(struct proc *p, int val)
412{
413
414	if (pti && val == PROC_KPTI_CTL_ENABLE_ON_EXEC)
415		p->p_md.md_flags |= P_MD_KPTI;
416	if (val == PROC_KPTI_CTL_DISABLE_ON_EXEC)
417		p->p_md.md_flags &= ~P_MD_KPTI;
418}
419
420static void
421cpu_procctl_kpti_status(struct proc *p, int *val)
422{
423	*val = (p->p_md.md_flags & P_MD_KPTI) != 0 ?
424	    PROC_KPTI_CTL_ENABLE_ON_EXEC:
425	    PROC_KPTI_CTL_DISABLE_ON_EXEC;
426	if (vmspace_pmap(p->p_vmspace)->pm_ucr3 != PMAP_NO_CR3)
427		*val |= PROC_KPTI_STATUS_ACTIVE;
428}
429
430static int
431cpu_procctl_la_ctl(struct proc *p, int val)
432{
433	int error;
434
435	error = 0;
436	switch (val) {
437	case PROC_LA_CTL_LA48_ON_EXEC:
438		p->p_md.md_flags |= P_MD_LA48;
439		p->p_md.md_flags &= ~P_MD_LA57;
440		break;
441	case PROC_LA_CTL_LA57_ON_EXEC:
442		if (la57) {
443			p->p_md.md_flags &= ~P_MD_LA48;
444			p->p_md.md_flags |= P_MD_LA57;
445		} else {
446			error = ENOTSUP;
447		}
448		break;
449	case PROC_LA_CTL_DEFAULT_ON_EXEC:
450		p->p_md.md_flags &= ~(P_MD_LA48 | P_MD_LA57);
451		break;
452	}
453	return (error);
454}
455
456static void
457cpu_procctl_la_status(struct proc *p, int *val)
458{
459	int res;
460
461	if ((p->p_md.md_flags & P_MD_LA48) != 0)
462		res = PROC_LA_CTL_LA48_ON_EXEC;
463	else if ((p->p_md.md_flags & P_MD_LA57) != 0)
464		res = PROC_LA_CTL_LA57_ON_EXEC;
465	else
466		res = PROC_LA_CTL_DEFAULT_ON_EXEC;
467	if (p->p_sysent->sv_maxuser == VM_MAXUSER_ADDRESS_LA48)
468		res |= PROC_LA_STATUS_LA48;
469	else
470		res |= PROC_LA_STATUS_LA57;
471	*val = res;
472}
473
474int
475cpu_procctl(struct thread *td, int idtype, id_t id, int com, void *data)
476{
477	struct proc *p;
478	int error, val;
479
480	switch (com) {
481	case PROC_KPTI_CTL:
482	case PROC_KPTI_STATUS:
483	case PROC_LA_CTL:
484	case PROC_LA_STATUS:
485		if (idtype != P_PID) {
486			error = EINVAL;
487			break;
488		}
489		if (com == PROC_KPTI_CTL) {
490			/* sad but true and not a joke */
491			error = priv_check(td, PRIV_IO);
492			if (error != 0)
493				break;
494		}
495		if (com == PROC_KPTI_CTL || com == PROC_LA_CTL) {
496			error = copyin(data, &val, sizeof(val));
497			if (error != 0)
498				break;
499		}
500		if (com == PROC_KPTI_CTL &&
501		    val != PROC_KPTI_CTL_ENABLE_ON_EXEC &&
502		    val != PROC_KPTI_CTL_DISABLE_ON_EXEC) {
503			error = EINVAL;
504			break;
505		}
506		if (com == PROC_LA_CTL &&
507		    val != PROC_LA_CTL_LA48_ON_EXEC &&
508		    val != PROC_LA_CTL_LA57_ON_EXEC &&
509		    val != PROC_LA_CTL_DEFAULT_ON_EXEC) {
510			error = EINVAL;
511			break;
512		}
513		error = pget(id, PGET_CANSEE | PGET_NOTWEXIT | PGET_NOTID, &p);
514		if (error != 0)
515			break;
516		switch (com) {
517		case PROC_KPTI_CTL:
518			cpu_procctl_kpti_ctl(p, val);
519			break;
520		case PROC_KPTI_STATUS:
521			cpu_procctl_kpti_status(p, &val);
522			break;
523		case PROC_LA_CTL:
524			error = cpu_procctl_la_ctl(p, val);
525			break;
526		case PROC_LA_STATUS:
527			cpu_procctl_la_status(p, &val);
528			break;
529		}
530		PROC_UNLOCK(p);
531		if (com == PROC_KPTI_STATUS || com == PROC_LA_STATUS)
532			error = copyout(&val, data, sizeof(val));
533		break;
534	default:
535		error = EINVAL;
536		break;
537	}
538	return (error);
539}
540
541void
542cpu_set_syscall_retval(struct thread *td, int error)
543{
544	struct trapframe *frame;
545
546	frame = td->td_frame;
547	if (__predict_true(error == 0)) {
548		frame->tf_rax = td->td_retval[0];
549		frame->tf_rdx = td->td_retval[1];
550		frame->tf_rflags &= ~PSL_C;
551		return;
552	}
553
554	switch (error) {
555	case ERESTART:
556		/*
557		 * Reconstruct pc, we know that 'syscall' is 2 bytes,
558		 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes.
559		 * We saved this in tf_err.
560		 * %r10 (which was holding the value of %rcx) is restored
561		 * for the next iteration.
562		 * %r10 restore is only required for freebsd/amd64 processes,
563		 * but shall be innocent for any ia32 ABI.
564		 *
565		 * Require full context restore to get the arguments
566		 * in the registers reloaded at return to usermode.
567		 */
568		frame->tf_rip -= frame->tf_err;
569		frame->tf_r10 = frame->tf_rcx;
570		set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
571		break;
572
573	case EJUSTRETURN:
574		break;
575
576	default:
577		frame->tf_rax = error;
578		frame->tf_rflags |= PSL_C;
579		break;
580	}
581}
582
583/*
584 * Initialize machine state, mostly pcb and trap frame for a new
585 * thread, about to return to userspace.  Put enough state in the new
586 * thread's PCB to get it to go back to the fork_return(), which
587 * finalizes the thread state and handles peculiarities of the first
588 * return to userspace for the new thread.
589 */
590void
591cpu_copy_thread(struct thread *td, struct thread *td0)
592{
593	copy_thread(td0, td);
594
595	/*
596	 * Copy user general-purpose registers.
597	 *
598	 * Some of these registers are rewritten by cpu_set_upcall()
599	 * and linux_set_upcall().
600	 */
601	bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
602
603	/* If the current thread has the trap bit set (i.e. a debugger had
604	 * single stepped the process to the system call), we need to clear
605	 * the trap flag from the new frame. Otherwise, the new thread will
606	 * receive a (likely unexpected) SIGTRAP when it executes the first
607	 * instruction after returning to userland.
608	 */
609	td->td_frame->tf_rflags &= ~PSL_T;
610
611	set_pcb_flags_raw(td->td_pcb, PCB_FULL_IRET);
612}
613
614/*
615 * Set that machine state for performing an upcall that starts
616 * the entry function with the given argument.
617 */
618void
619cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg,
620    stack_t *stack)
621{
622
623	/*
624	 * Do any extra cleaning that needs to be done.
625	 * The thread may have optional components
626	 * that are not present in a fresh thread.
627	 * This may be a recycled thread so make it look
628	 * as though it's newly allocated.
629	 */
630	cpu_thread_clean(td);
631
632#ifdef COMPAT_FREEBSD32
633	if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
634		/*
635		 * Set the trap frame to point at the beginning of the entry
636		 * function.
637		 */
638		td->td_frame->tf_rbp = 0;
639		td->td_frame->tf_rsp =
640		   (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
641		td->td_frame->tf_rip = (uintptr_t)entry;
642
643		/* Return address sentinel value to stop stack unwinding. */
644		suword32((void *)td->td_frame->tf_rsp, 0);
645
646		/* Pass the argument to the entry point. */
647		suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)),
648		    (uint32_t)(uintptr_t)arg);
649
650		return;
651	}
652#endif
653
654	/*
655	 * Set the trap frame to point at the beginning of the uts
656	 * function.
657	 */
658	td->td_frame->tf_rbp = 0;
659	td->td_frame->tf_rsp =
660	    ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f;
661	td->td_frame->tf_rsp -= 8;
662	td->td_frame->tf_rip = (register_t)entry;
663	td->td_frame->tf_ds = _udatasel;
664	td->td_frame->tf_es = _udatasel;
665	td->td_frame->tf_fs = _ufssel;
666	td->td_frame->tf_gs = _ugssel;
667	td->td_frame->tf_flags = TF_HASSEGS;
668
669	/* Return address sentinel value to stop stack unwinding. */
670	suword((void *)td->td_frame->tf_rsp, 0);
671
672	/* Pass the argument to the entry point. */
673	td->td_frame->tf_rdi = (register_t)arg;
674}
675
676int
677cpu_set_user_tls(struct thread *td, void *tls_base)
678{
679	struct pcb *pcb;
680
681	if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS)
682		return (EINVAL);
683
684	pcb = td->td_pcb;
685	set_pcb_flags(pcb, PCB_FULL_IRET);
686#ifdef COMPAT_FREEBSD32
687	if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
688		pcb->pcb_gsbase = (register_t)tls_base;
689		return (0);
690	}
691#endif
692	pcb->pcb_fsbase = (register_t)tls_base;
693	return (0);
694}
695
696/*
697 * Software interrupt handler for queued VM system processing.
698 */
699void
700swi_vm(void *dummy)
701{
702	if (busdma_swi_pending != 0)
703		busdma_swi();
704}
705
706/*
707 * Tell whether this address is in some physical memory region.
708 * Currently used by the kernel coredump code in order to avoid
709 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
710 * or other unpredictable behaviour.
711 */
712
713int
714is_physical_memory(vm_paddr_t addr)
715{
716
717#ifdef DEV_ISA
718	/* The ISA ``memory hole''. */
719	if (addr >= 0xa0000 && addr < 0x100000)
720		return 0;
721#endif
722
723	/*
724	 * stuff other tests for known memory-mapped devices (PCI?)
725	 * here
726	 */
727
728	return 1;
729}
730