xref: /freebsd/sys/i386/i386/machdep.c (revision 148a8da8)
1 /*-
2  * SPDX-License-Identifier: BSD-4-Clause
3  *
4  * Copyright (c) 2018 The FreeBSD Foundation
5  * Copyright (c) 1992 Terrence R. Lambert.
6  * Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * William Jolitz.
11  *
12  * Portions of this software were developed by A. Joseph Koshy under
13  * sponsorship from the FreeBSD Foundation and Google, Inc.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  * 3. All advertising materials mentioning features or use of this software
24  *    must display the following acknowledgement:
25  *	This product includes software developed by the University of
26  *	California, Berkeley and its contributors.
27  * 4. Neither the name of the University nor the names of its contributors
28  *    may be used to endorse or promote products derived from this software
29  *    without specific prior written permission.
30  *
31  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41  * SUCH DAMAGE.
42  *
43  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
44  */
45 
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 #include "opt_apic.h"
50 #include "opt_atpic.h"
51 #include "opt_cpu.h"
52 #include "opt_ddb.h"
53 #include "opt_inet.h"
54 #include "opt_isa.h"
55 #include "opt_kstack_pages.h"
56 #include "opt_maxmem.h"
57 #include "opt_mp_watchdog.h"
58 #include "opt_perfmon.h"
59 #include "opt_platform.h"
60 
61 #include <sys/param.h>
62 #include <sys/proc.h>
63 #include <sys/systm.h>
64 #include <sys/bio.h>
65 #include <sys/buf.h>
66 #include <sys/bus.h>
67 #include <sys/callout.h>
68 #include <sys/cons.h>
69 #include <sys/cpu.h>
70 #include <sys/eventhandler.h>
71 #include <sys/exec.h>
72 #include <sys/imgact.h>
73 #include <sys/kdb.h>
74 #include <sys/kernel.h>
75 #include <sys/ktr.h>
76 #include <sys/linker.h>
77 #include <sys/lock.h>
78 #include <sys/malloc.h>
79 #include <sys/memrange.h>
80 #include <sys/msgbuf.h>
81 #include <sys/mutex.h>
82 #include <sys/pcpu.h>
83 #include <sys/ptrace.h>
84 #include <sys/reboot.h>
85 #include <sys/rwlock.h>
86 #include <sys/sched.h>
87 #include <sys/signalvar.h>
88 #include <sys/smp.h>
89 #include <sys/syscallsubr.h>
90 #include <sys/sysctl.h>
91 #include <sys/sysent.h>
92 #include <sys/sysproto.h>
93 #include <sys/ucontext.h>
94 #include <sys/vmmeter.h>
95 
96 #include <vm/vm.h>
97 #include <vm/vm_extern.h>
98 #include <vm/vm_kern.h>
99 #include <vm/vm_page.h>
100 #include <vm/vm_map.h>
101 #include <vm/vm_object.h>
102 #include <vm/vm_pager.h>
103 #include <vm/vm_param.h>
104 #include <vm/vm_phys.h>
105 
106 #ifdef DDB
107 #ifndef KDB
108 #error KDB must be enabled in order for DDB to work!
109 #endif
110 #include <ddb/ddb.h>
111 #include <ddb/db_sym.h>
112 #endif
113 
114 #include <isa/rtc.h>
115 
116 #include <net/netisr.h>
117 
118 #include <machine/bootinfo.h>
119 #include <machine/clock.h>
120 #include <machine/cpu.h>
121 #include <machine/cputypes.h>
122 #include <machine/intr_machdep.h>
123 #include <x86/mca.h>
124 #include <machine/md_var.h>
125 #include <machine/metadata.h>
126 #include <machine/mp_watchdog.h>
127 #include <machine/pc/bios.h>
128 #include <machine/pcb.h>
129 #include <machine/pcb_ext.h>
130 #include <machine/proc.h>
131 #include <machine/reg.h>
132 #include <machine/sigframe.h>
133 #include <machine/specialreg.h>
134 #include <machine/sysarch.h>
135 #include <machine/trap.h>
136 #include <x86/ucode.h>
137 #include <machine/vm86.h>
138 #include <x86/init.h>
139 #ifdef PERFMON
140 #include <machine/perfmon.h>
141 #endif
142 #ifdef SMP
143 #include <machine/smp.h>
144 #endif
145 #ifdef FDT
146 #include <x86/fdt.h>
147 #endif
148 
149 #ifdef DEV_APIC
150 #include <x86/apicvar.h>
151 #endif
152 
153 #ifdef DEV_ISA
154 #include <x86/isa/icu.h>
155 #endif
156 
157 /* Sanity check for __curthread() */
158 CTASSERT(offsetof(struct pcpu, pc_curthread) == 0);
159 
160 register_t init386(int first);
161 void dblfault_handler(void);
162 void identify_cpu(void);
163 
164 static void cpu_startup(void *);
165 static void fpstate_drop(struct thread *td);
166 static void get_fpcontext(struct thread *td, mcontext_t *mcp,
167     char *xfpusave, size_t xfpusave_len);
168 static int  set_fpcontext(struct thread *td, mcontext_t *mcp,
169     char *xfpustate, size_t xfpustate_len);
170 SYSINIT(cpu, SI_SUB_CPU, SI_ORDER_FIRST, cpu_startup, NULL);
171 
172 /* Intel ICH registers */
173 #define ICH_PMBASE	0x400
174 #define ICH_SMI_EN	ICH_PMBASE + 0x30
175 
176 int	_udatasel, _ucodesel;
177 u_int	basemem;
178 static int above4g_allow = 1;
179 static int above24g_allow = 0;
180 
181 int cold = 1;
182 
183 #ifdef COMPAT_43
184 static void osendsig(sig_t catcher, ksiginfo_t *, sigset_t *mask);
185 #endif
186 #ifdef COMPAT_FREEBSD4
187 static void freebsd4_sendsig(sig_t catcher, ksiginfo_t *, sigset_t *mask);
188 #endif
189 
190 long Maxmem = 0;
191 long realmem = 0;
192 
193 #ifdef PAE
194 FEATURE(pae, "Physical Address Extensions");
195 #endif
196 
197 /*
198  * The number of PHYSMAP entries must be one less than the number of
199  * PHYSSEG entries because the PHYSMAP entry that spans the largest
200  * physical address that is accessible by ISA DMA is split into two
201  * PHYSSEG entries.
202  */
203 #define	PHYSMAP_SIZE	(2 * (VM_PHYSSEG_MAX - 1))
204 
205 vm_paddr_t phys_avail[PHYSMAP_SIZE + 2];
206 vm_paddr_t dump_avail[PHYSMAP_SIZE + 2];
207 
208 /* must be 2 less so 0 0 can signal end of chunks */
209 #define	PHYS_AVAIL_ARRAY_END (nitems(phys_avail) - 2)
210 #define	DUMP_AVAIL_ARRAY_END (nitems(dump_avail) - 2)
211 
212 struct kva_md_info kmi;
213 
214 static struct trapframe proc0_tf;
215 struct pcpu __pcpu[MAXCPU];
216 
217 struct mtx icu_lock;
218 
219 struct mem_range_softc mem_range_softc;
220 
221 extern char start_exceptions[], end_exceptions[];
222 
223 extern struct sysentvec elf32_freebsd_sysvec;
224 
225 /* Default init_ops implementation. */
226 struct init_ops init_ops = {
227 	.early_clock_source_init =	i8254_init,
228 	.early_delay =			i8254_delay,
229 #ifdef DEV_APIC
230 	.msi_init =			msi_init,
231 #endif
232 };
233 
234 static void
235 cpu_startup(dummy)
236 	void *dummy;
237 {
238 	uintmax_t memsize;
239 	char *sysenv;
240 
241 	/*
242 	 * On MacBooks, we need to disallow the legacy USB circuit to
243 	 * generate an SMI# because this can cause several problems,
244 	 * namely: incorrect CPU frequency detection and failure to
245 	 * start the APs.
246 	 * We do this by disabling a bit in the SMI_EN (SMI Control and
247 	 * Enable register) of the Intel ICH LPC Interface Bridge.
248 	 */
249 	sysenv = kern_getenv("smbios.system.product");
250 	if (sysenv != NULL) {
251 		if (strncmp(sysenv, "MacBook1,1", 10) == 0 ||
252 		    strncmp(sysenv, "MacBook3,1", 10) == 0 ||
253 		    strncmp(sysenv, "MacBook4,1", 10) == 0 ||
254 		    strncmp(sysenv, "MacBookPro1,1", 13) == 0 ||
255 		    strncmp(sysenv, "MacBookPro1,2", 13) == 0 ||
256 		    strncmp(sysenv, "MacBookPro3,1", 13) == 0 ||
257 		    strncmp(sysenv, "MacBookPro4,1", 13) == 0 ||
258 		    strncmp(sysenv, "Macmini1,1", 10) == 0) {
259 			if (bootverbose)
260 				printf("Disabling LEGACY_USB_EN bit on "
261 				    "Intel ICH.\n");
262 			outl(ICH_SMI_EN, inl(ICH_SMI_EN) & ~0x8);
263 		}
264 		freeenv(sysenv);
265 	}
266 
267 	/*
268 	 * Good {morning,afternoon,evening,night}.
269 	 */
270 	startrtclock();
271 	printcpuinfo();
272 	panicifcpuunsupported();
273 #ifdef PERFMON
274 	perfmon_init();
275 #endif
276 
277 	/*
278 	 * Display physical memory if SMBIOS reports reasonable amount.
279 	 */
280 	memsize = 0;
281 	sysenv = kern_getenv("smbios.memory.enabled");
282 	if (sysenv != NULL) {
283 		memsize = (uintmax_t)strtoul(sysenv, (char **)NULL, 10) << 10;
284 		freeenv(sysenv);
285 	}
286 	if (memsize < ptoa((uintmax_t)vm_free_count()))
287 		memsize = ptoa((uintmax_t)Maxmem);
288 	printf("real memory  = %ju (%ju MB)\n", memsize, memsize >> 20);
289 	realmem = atop(memsize);
290 
291 	/*
292 	 * Display any holes after the first chunk of extended memory.
293 	 */
294 	if (bootverbose) {
295 		int indx;
296 
297 		printf("Physical memory chunk(s):\n");
298 		for (indx = 0; phys_avail[indx + 1] != 0; indx += 2) {
299 			vm_paddr_t size;
300 
301 			size = phys_avail[indx + 1] - phys_avail[indx];
302 			printf(
303 			    "0x%016jx - 0x%016jx, %ju bytes (%ju pages)\n",
304 			    (uintmax_t)phys_avail[indx],
305 			    (uintmax_t)phys_avail[indx + 1] - 1,
306 			    (uintmax_t)size, (uintmax_t)size / PAGE_SIZE);
307 		}
308 	}
309 
310 	vm_ksubmap_init(&kmi);
311 
312 	printf("avail memory = %ju (%ju MB)\n",
313 	    ptoa((uintmax_t)vm_free_count()),
314 	    ptoa((uintmax_t)vm_free_count()) / 1048576);
315 
316 	/*
317 	 * Set up buffers, so they can be used to read disk labels.
318 	 */
319 	bufinit();
320 	vm_pager_bufferinit();
321 	cpu_setregs();
322 }
323 
324 /*
325  * Send an interrupt to process.
326  *
327  * Stack is set up to allow sigcode stored
328  * at top to call routine, followed by call
329  * to sigreturn routine below.  After sigreturn
330  * resets the signal mask, the stack, and the
331  * frame pointer, it returns to the user
332  * specified pc, psl.
333  */
334 #ifdef COMPAT_43
335 static void
336 osendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
337 {
338 	struct osigframe sf, *fp;
339 	struct proc *p;
340 	struct thread *td;
341 	struct sigacts *psp;
342 	struct trapframe *regs;
343 	int sig;
344 	int oonstack;
345 
346 	td = curthread;
347 	p = td->td_proc;
348 	PROC_LOCK_ASSERT(p, MA_OWNED);
349 	sig = ksi->ksi_signo;
350 	psp = p->p_sigacts;
351 	mtx_assert(&psp->ps_mtx, MA_OWNED);
352 	regs = td->td_frame;
353 	oonstack = sigonstack(regs->tf_esp);
354 
355 	/* Allocate space for the signal handler context. */
356 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
357 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
358 		fp = (struct osigframe *)((uintptr_t)td->td_sigstk.ss_sp +
359 		    td->td_sigstk.ss_size - sizeof(struct osigframe));
360 #if defined(COMPAT_43)
361 		td->td_sigstk.ss_flags |= SS_ONSTACK;
362 #endif
363 	} else
364 		fp = (struct osigframe *)regs->tf_esp - 1;
365 
366 	/* Build the argument list for the signal handler. */
367 	sf.sf_signum = sig;
368 	sf.sf_scp = (register_t)&fp->sf_siginfo.si_sc;
369 	bzero(&sf.sf_siginfo, sizeof(sf.sf_siginfo));
370 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
371 		/* Signal handler installed with SA_SIGINFO. */
372 		sf.sf_arg2 = (register_t)&fp->sf_siginfo;
373 		sf.sf_siginfo.si_signo = sig;
374 		sf.sf_siginfo.si_code = ksi->ksi_code;
375 		sf.sf_ahu.sf_action = (__osiginfohandler_t *)catcher;
376 		sf.sf_addr = 0;
377 	} else {
378 		/* Old FreeBSD-style arguments. */
379 		sf.sf_arg2 = ksi->ksi_code;
380 		sf.sf_addr = (register_t)ksi->ksi_addr;
381 		sf.sf_ahu.sf_handler = catcher;
382 	}
383 	mtx_unlock(&psp->ps_mtx);
384 	PROC_UNLOCK(p);
385 
386 	/* Save most if not all of trap frame. */
387 	sf.sf_siginfo.si_sc.sc_eax = regs->tf_eax;
388 	sf.sf_siginfo.si_sc.sc_ebx = regs->tf_ebx;
389 	sf.sf_siginfo.si_sc.sc_ecx = regs->tf_ecx;
390 	sf.sf_siginfo.si_sc.sc_edx = regs->tf_edx;
391 	sf.sf_siginfo.si_sc.sc_esi = regs->tf_esi;
392 	sf.sf_siginfo.si_sc.sc_edi = regs->tf_edi;
393 	sf.sf_siginfo.si_sc.sc_cs = regs->tf_cs;
394 	sf.sf_siginfo.si_sc.sc_ds = regs->tf_ds;
395 	sf.sf_siginfo.si_sc.sc_ss = regs->tf_ss;
396 	sf.sf_siginfo.si_sc.sc_es = regs->tf_es;
397 	sf.sf_siginfo.si_sc.sc_fs = regs->tf_fs;
398 	sf.sf_siginfo.si_sc.sc_gs = rgs();
399 	sf.sf_siginfo.si_sc.sc_isp = regs->tf_isp;
400 
401 	/* Build the signal context to be used by osigreturn(). */
402 	sf.sf_siginfo.si_sc.sc_onstack = (oonstack) ? 1 : 0;
403 	SIG2OSIG(*mask, sf.sf_siginfo.si_sc.sc_mask);
404 	sf.sf_siginfo.si_sc.sc_sp = regs->tf_esp;
405 	sf.sf_siginfo.si_sc.sc_fp = regs->tf_ebp;
406 	sf.sf_siginfo.si_sc.sc_pc = regs->tf_eip;
407 	sf.sf_siginfo.si_sc.sc_ps = regs->tf_eflags;
408 	sf.sf_siginfo.si_sc.sc_trapno = regs->tf_trapno;
409 	sf.sf_siginfo.si_sc.sc_err = regs->tf_err;
410 
411 	/*
412 	 * If we're a vm86 process, we want to save the segment registers.
413 	 * We also change eflags to be our emulated eflags, not the actual
414 	 * eflags.
415 	 */
416 	if (regs->tf_eflags & PSL_VM) {
417 		/* XXX confusing names: `tf' isn't a trapframe; `regs' is. */
418 		struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs;
419 		struct vm86_kernel *vm86 = &td->td_pcb->pcb_ext->ext_vm86;
420 
421 		sf.sf_siginfo.si_sc.sc_gs = tf->tf_vm86_gs;
422 		sf.sf_siginfo.si_sc.sc_fs = tf->tf_vm86_fs;
423 		sf.sf_siginfo.si_sc.sc_es = tf->tf_vm86_es;
424 		sf.sf_siginfo.si_sc.sc_ds = tf->tf_vm86_ds;
425 
426 		if (vm86->vm86_has_vme == 0)
427 			sf.sf_siginfo.si_sc.sc_ps =
428 			    (tf->tf_eflags & ~(PSL_VIF | PSL_VIP)) |
429 			    (vm86->vm86_eflags & (PSL_VIF | PSL_VIP));
430 
431 		/* See sendsig() for comments. */
432 		tf->tf_eflags &= ~(PSL_VM | PSL_NT | PSL_VIF | PSL_VIP);
433 	}
434 
435 	/*
436 	 * Copy the sigframe out to the user's stack.
437 	 */
438 	if (copyout(&sf, fp, sizeof(*fp)) != 0) {
439 		PROC_LOCK(p);
440 		sigexit(td, SIGILL);
441 	}
442 
443 	regs->tf_esp = (int)fp;
444 	if (p->p_sysent->sv_sigcode_base != 0) {
445 		regs->tf_eip = p->p_sysent->sv_sigcode_base + szsigcode -
446 		    szosigcode;
447 	} else {
448 		/* a.out sysentvec does not use shared page */
449 		regs->tf_eip = p->p_sysent->sv_psstrings - szosigcode;
450 	}
451 	regs->tf_eflags &= ~(PSL_T | PSL_D);
452 	regs->tf_cs = _ucodesel;
453 	regs->tf_ds = _udatasel;
454 	regs->tf_es = _udatasel;
455 	regs->tf_fs = _udatasel;
456 	load_gs(_udatasel);
457 	regs->tf_ss = _udatasel;
458 	PROC_LOCK(p);
459 	mtx_lock(&psp->ps_mtx);
460 }
461 #endif /* COMPAT_43 */
462 
463 #ifdef COMPAT_FREEBSD4
464 static void
465 freebsd4_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
466 {
467 	struct sigframe4 sf, *sfp;
468 	struct proc *p;
469 	struct thread *td;
470 	struct sigacts *psp;
471 	struct trapframe *regs;
472 	int sig;
473 	int oonstack;
474 
475 	td = curthread;
476 	p = td->td_proc;
477 	PROC_LOCK_ASSERT(p, MA_OWNED);
478 	sig = ksi->ksi_signo;
479 	psp = p->p_sigacts;
480 	mtx_assert(&psp->ps_mtx, MA_OWNED);
481 	regs = td->td_frame;
482 	oonstack = sigonstack(regs->tf_esp);
483 
484 	/* Save user context. */
485 	bzero(&sf, sizeof(sf));
486 	sf.sf_uc.uc_sigmask = *mask;
487 	sf.sf_uc.uc_stack = td->td_sigstk;
488 	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
489 	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
490 	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
491 	sf.sf_uc.uc_mcontext.mc_gs = rgs();
492 	bcopy(regs, &sf.sf_uc.uc_mcontext.mc_fs, sizeof(*regs));
493 	bzero(sf.sf_uc.uc_mcontext.mc_fpregs,
494 	    sizeof(sf.sf_uc.uc_mcontext.mc_fpregs));
495 	bzero(sf.sf_uc.uc_mcontext.__spare__,
496 	    sizeof(sf.sf_uc.uc_mcontext.__spare__));
497 	bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__));
498 
499 	/* Allocate space for the signal handler context. */
500 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
501 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
502 		sfp = (struct sigframe4 *)((uintptr_t)td->td_sigstk.ss_sp +
503 		    td->td_sigstk.ss_size - sizeof(struct sigframe4));
504 #if defined(COMPAT_43)
505 		td->td_sigstk.ss_flags |= SS_ONSTACK;
506 #endif
507 	} else
508 		sfp = (struct sigframe4 *)regs->tf_esp - 1;
509 
510 	/* Build the argument list for the signal handler. */
511 	sf.sf_signum = sig;
512 	sf.sf_ucontext = (register_t)&sfp->sf_uc;
513 	bzero(&sf.sf_si, sizeof(sf.sf_si));
514 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
515 		/* Signal handler installed with SA_SIGINFO. */
516 		sf.sf_siginfo = (register_t)&sfp->sf_si;
517 		sf.sf_ahu.sf_action = (__siginfohandler_t *)catcher;
518 
519 		/* Fill in POSIX parts */
520 		sf.sf_si.si_signo = sig;
521 		sf.sf_si.si_code = ksi->ksi_code;
522 		sf.sf_si.si_addr = ksi->ksi_addr;
523 	} else {
524 		/* Old FreeBSD-style arguments. */
525 		sf.sf_siginfo = ksi->ksi_code;
526 		sf.sf_addr = (register_t)ksi->ksi_addr;
527 		sf.sf_ahu.sf_handler = catcher;
528 	}
529 	mtx_unlock(&psp->ps_mtx);
530 	PROC_UNLOCK(p);
531 
532 	/*
533 	 * If we're a vm86 process, we want to save the segment registers.
534 	 * We also change eflags to be our emulated eflags, not the actual
535 	 * eflags.
536 	 */
537 	if (regs->tf_eflags & PSL_VM) {
538 		struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs;
539 		struct vm86_kernel *vm86 = &td->td_pcb->pcb_ext->ext_vm86;
540 
541 		sf.sf_uc.uc_mcontext.mc_gs = tf->tf_vm86_gs;
542 		sf.sf_uc.uc_mcontext.mc_fs = tf->tf_vm86_fs;
543 		sf.sf_uc.uc_mcontext.mc_es = tf->tf_vm86_es;
544 		sf.sf_uc.uc_mcontext.mc_ds = tf->tf_vm86_ds;
545 
546 		if (vm86->vm86_has_vme == 0)
547 			sf.sf_uc.uc_mcontext.mc_eflags =
548 			    (tf->tf_eflags & ~(PSL_VIF | PSL_VIP)) |
549 			    (vm86->vm86_eflags & (PSL_VIF | PSL_VIP));
550 
551 		/*
552 		 * Clear PSL_NT to inhibit T_TSSFLT faults on return from
553 		 * syscalls made by the signal handler.  This just avoids
554 		 * wasting time for our lazy fixup of such faults.  PSL_NT
555 		 * does nothing in vm86 mode, but vm86 programs can set it
556 		 * almost legitimately in probes for old cpu types.
557 		 */
558 		tf->tf_eflags &= ~(PSL_VM | PSL_NT | PSL_VIF | PSL_VIP);
559 	}
560 
561 	/*
562 	 * Copy the sigframe out to the user's stack.
563 	 */
564 	if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
565 		PROC_LOCK(p);
566 		sigexit(td, SIGILL);
567 	}
568 
569 	regs->tf_esp = (int)sfp;
570 	regs->tf_eip = p->p_sysent->sv_sigcode_base + szsigcode -
571 	    szfreebsd4_sigcode;
572 	regs->tf_eflags &= ~(PSL_T | PSL_D);
573 	regs->tf_cs = _ucodesel;
574 	regs->tf_ds = _udatasel;
575 	regs->tf_es = _udatasel;
576 	regs->tf_fs = _udatasel;
577 	regs->tf_ss = _udatasel;
578 	PROC_LOCK(p);
579 	mtx_lock(&psp->ps_mtx);
580 }
581 #endif	/* COMPAT_FREEBSD4 */
582 
583 void
584 sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
585 {
586 	struct sigframe sf, *sfp;
587 	struct proc *p;
588 	struct thread *td;
589 	struct sigacts *psp;
590 	char *sp;
591 	struct trapframe *regs;
592 	struct segment_descriptor *sdp;
593 	char *xfpusave;
594 	size_t xfpusave_len;
595 	int sig;
596 	int oonstack;
597 
598 	td = curthread;
599 	p = td->td_proc;
600 	PROC_LOCK_ASSERT(p, MA_OWNED);
601 	sig = ksi->ksi_signo;
602 	psp = p->p_sigacts;
603 	mtx_assert(&psp->ps_mtx, MA_OWNED);
604 #ifdef COMPAT_FREEBSD4
605 	if (SIGISMEMBER(psp->ps_freebsd4, sig)) {
606 		freebsd4_sendsig(catcher, ksi, mask);
607 		return;
608 	}
609 #endif
610 #ifdef COMPAT_43
611 	if (SIGISMEMBER(psp->ps_osigset, sig)) {
612 		osendsig(catcher, ksi, mask);
613 		return;
614 	}
615 #endif
616 	regs = td->td_frame;
617 	oonstack = sigonstack(regs->tf_esp);
618 
619 	if (cpu_max_ext_state_size > sizeof(union savefpu) && use_xsave) {
620 		xfpusave_len = cpu_max_ext_state_size - sizeof(union savefpu);
621 		xfpusave = __builtin_alloca(xfpusave_len);
622 	} else {
623 		xfpusave_len = 0;
624 		xfpusave = NULL;
625 	}
626 
627 	/* Save user context. */
628 	bzero(&sf, sizeof(sf));
629 	sf.sf_uc.uc_sigmask = *mask;
630 	sf.sf_uc.uc_stack = td->td_sigstk;
631 	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
632 	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
633 	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
634 	sf.sf_uc.uc_mcontext.mc_gs = rgs();
635 	bcopy(regs, &sf.sf_uc.uc_mcontext.mc_fs, sizeof(*regs));
636 	sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */
637 	get_fpcontext(td, &sf.sf_uc.uc_mcontext, xfpusave, xfpusave_len);
638 	fpstate_drop(td);
639 	/*
640 	 * Unconditionally fill the fsbase and gsbase into the mcontext.
641 	 */
642 	sdp = &td->td_pcb->pcb_fsd;
643 	sf.sf_uc.uc_mcontext.mc_fsbase = sdp->sd_hibase << 24 |
644 	    sdp->sd_lobase;
645 	sdp = &td->td_pcb->pcb_gsd;
646 	sf.sf_uc.uc_mcontext.mc_gsbase = sdp->sd_hibase << 24 |
647 	    sdp->sd_lobase;
648 	bzero(sf.sf_uc.uc_mcontext.mc_spare2,
649 	    sizeof(sf.sf_uc.uc_mcontext.mc_spare2));
650 
651 	/* Allocate space for the signal handler context. */
652 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
653 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
654 		sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size;
655 #if defined(COMPAT_43)
656 		td->td_sigstk.ss_flags |= SS_ONSTACK;
657 #endif
658 	} else
659 		sp = (char *)regs->tf_esp - 128;
660 	if (xfpusave != NULL) {
661 		sp -= xfpusave_len;
662 		sp = (char *)((unsigned int)sp & ~0x3F);
663 		sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp;
664 	}
665 	sp -= sizeof(struct sigframe);
666 
667 	/* Align to 16 bytes. */
668 	sfp = (struct sigframe *)((unsigned int)sp & ~0xF);
669 
670 	/* Build the argument list for the signal handler. */
671 	sf.sf_signum = sig;
672 	sf.sf_ucontext = (register_t)&sfp->sf_uc;
673 	bzero(&sf.sf_si, sizeof(sf.sf_si));
674 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
675 		/* Signal handler installed with SA_SIGINFO. */
676 		sf.sf_siginfo = (register_t)&sfp->sf_si;
677 		sf.sf_ahu.sf_action = (__siginfohandler_t *)catcher;
678 
679 		/* Fill in POSIX parts */
680 		sf.sf_si = ksi->ksi_info;
681 		sf.sf_si.si_signo = sig; /* maybe a translated signal */
682 	} else {
683 		/* Old FreeBSD-style arguments. */
684 		sf.sf_siginfo = ksi->ksi_code;
685 		sf.sf_addr = (register_t)ksi->ksi_addr;
686 		sf.sf_ahu.sf_handler = catcher;
687 	}
688 	mtx_unlock(&psp->ps_mtx);
689 	PROC_UNLOCK(p);
690 
691 	/*
692 	 * If we're a vm86 process, we want to save the segment registers.
693 	 * We also change eflags to be our emulated eflags, not the actual
694 	 * eflags.
695 	 */
696 	if (regs->tf_eflags & PSL_VM) {
697 		struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs;
698 		struct vm86_kernel *vm86 = &td->td_pcb->pcb_ext->ext_vm86;
699 
700 		sf.sf_uc.uc_mcontext.mc_gs = tf->tf_vm86_gs;
701 		sf.sf_uc.uc_mcontext.mc_fs = tf->tf_vm86_fs;
702 		sf.sf_uc.uc_mcontext.mc_es = tf->tf_vm86_es;
703 		sf.sf_uc.uc_mcontext.mc_ds = tf->tf_vm86_ds;
704 
705 		if (vm86->vm86_has_vme == 0)
706 			sf.sf_uc.uc_mcontext.mc_eflags =
707 			    (tf->tf_eflags & ~(PSL_VIF | PSL_VIP)) |
708 			    (vm86->vm86_eflags & (PSL_VIF | PSL_VIP));
709 
710 		/*
711 		 * Clear PSL_NT to inhibit T_TSSFLT faults on return from
712 		 * syscalls made by the signal handler.  This just avoids
713 		 * wasting time for our lazy fixup of such faults.  PSL_NT
714 		 * does nothing in vm86 mode, but vm86 programs can set it
715 		 * almost legitimately in probes for old cpu types.
716 		 */
717 		tf->tf_eflags &= ~(PSL_VM | PSL_NT | PSL_VIF | PSL_VIP);
718 	}
719 
720 	/*
721 	 * Copy the sigframe out to the user's stack.
722 	 */
723 	if (copyout(&sf, sfp, sizeof(*sfp)) != 0 ||
724 	    (xfpusave != NULL && copyout(xfpusave,
725 	    (void *)sf.sf_uc.uc_mcontext.mc_xfpustate, xfpusave_len)
726 	    != 0)) {
727 		PROC_LOCK(p);
728 		sigexit(td, SIGILL);
729 	}
730 
731 	regs->tf_esp = (int)sfp;
732 	regs->tf_eip = p->p_sysent->sv_sigcode_base;
733 	if (regs->tf_eip == 0)
734 		regs->tf_eip = p->p_sysent->sv_psstrings - szsigcode;
735 	regs->tf_eflags &= ~(PSL_T | PSL_D);
736 	regs->tf_cs = _ucodesel;
737 	regs->tf_ds = _udatasel;
738 	regs->tf_es = _udatasel;
739 	regs->tf_fs = _udatasel;
740 	regs->tf_ss = _udatasel;
741 	PROC_LOCK(p);
742 	mtx_lock(&psp->ps_mtx);
743 }
744 
745 /*
746  * System call to cleanup state after a signal
747  * has been taken.  Reset signal mask and
748  * stack state from context left by sendsig (above).
749  * Return to previous pc and psl as specified by
750  * context left by sendsig. Check carefully to
751  * make sure that the user has not modified the
752  * state to gain improper privileges.
753  *
754  * MPSAFE
755  */
756 #ifdef COMPAT_43
757 int
758 osigreturn(td, uap)
759 	struct thread *td;
760 	struct osigreturn_args /* {
761 		struct osigcontext *sigcntxp;
762 	} */ *uap;
763 {
764 	struct osigcontext sc;
765 	struct trapframe *regs;
766 	struct osigcontext *scp;
767 	int eflags, error;
768 	ksiginfo_t ksi;
769 
770 	regs = td->td_frame;
771 	error = copyin(uap->sigcntxp, &sc, sizeof(sc));
772 	if (error != 0)
773 		return (error);
774 	scp = &sc;
775 	eflags = scp->sc_ps;
776 	if (eflags & PSL_VM) {
777 		struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs;
778 		struct vm86_kernel *vm86;
779 
780 		/*
781 		 * if pcb_ext == 0 or vm86_inited == 0, the user hasn't
782 		 * set up the vm86 area, and we can't enter vm86 mode.
783 		 */
784 		if (td->td_pcb->pcb_ext == 0)
785 			return (EINVAL);
786 		vm86 = &td->td_pcb->pcb_ext->ext_vm86;
787 		if (vm86->vm86_inited == 0)
788 			return (EINVAL);
789 
790 		/* Go back to user mode if both flags are set. */
791 		if ((eflags & PSL_VIP) && (eflags & PSL_VIF)) {
792 			ksiginfo_init_trap(&ksi);
793 			ksi.ksi_signo = SIGBUS;
794 			ksi.ksi_code = BUS_OBJERR;
795 			ksi.ksi_addr = (void *)regs->tf_eip;
796 			trapsignal(td, &ksi);
797 		}
798 
799 		if (vm86->vm86_has_vme) {
800 			eflags = (tf->tf_eflags & ~VME_USERCHANGE) |
801 			    (eflags & VME_USERCHANGE) | PSL_VM;
802 		} else {
803 			vm86->vm86_eflags = eflags;	/* save VIF, VIP */
804 			eflags = (tf->tf_eflags & ~VM_USERCHANGE) |
805 			    (eflags & VM_USERCHANGE) | PSL_VM;
806 		}
807 		tf->tf_vm86_ds = scp->sc_ds;
808 		tf->tf_vm86_es = scp->sc_es;
809 		tf->tf_vm86_fs = scp->sc_fs;
810 		tf->tf_vm86_gs = scp->sc_gs;
811 		tf->tf_ds = _udatasel;
812 		tf->tf_es = _udatasel;
813 		tf->tf_fs = _udatasel;
814 	} else {
815 		/*
816 		 * Don't allow users to change privileged or reserved flags.
817 		 */
818 		if (!EFL_SECURE(eflags, regs->tf_eflags)) {
819 	    		return (EINVAL);
820 		}
821 
822 		/*
823 		 * Don't allow users to load a valid privileged %cs.  Let the
824 		 * hardware check for invalid selectors, excess privilege in
825 		 * other selectors, invalid %eip's and invalid %esp's.
826 		 */
827 		if (!CS_SECURE(scp->sc_cs)) {
828 			ksiginfo_init_trap(&ksi);
829 			ksi.ksi_signo = SIGBUS;
830 			ksi.ksi_code = BUS_OBJERR;
831 			ksi.ksi_trapno = T_PROTFLT;
832 			ksi.ksi_addr = (void *)regs->tf_eip;
833 			trapsignal(td, &ksi);
834 			return (EINVAL);
835 		}
836 		regs->tf_ds = scp->sc_ds;
837 		regs->tf_es = scp->sc_es;
838 		regs->tf_fs = scp->sc_fs;
839 	}
840 
841 	/* Restore remaining registers. */
842 	regs->tf_eax = scp->sc_eax;
843 	regs->tf_ebx = scp->sc_ebx;
844 	regs->tf_ecx = scp->sc_ecx;
845 	regs->tf_edx = scp->sc_edx;
846 	regs->tf_esi = scp->sc_esi;
847 	regs->tf_edi = scp->sc_edi;
848 	regs->tf_cs = scp->sc_cs;
849 	regs->tf_ss = scp->sc_ss;
850 	regs->tf_isp = scp->sc_isp;
851 	regs->tf_ebp = scp->sc_fp;
852 	regs->tf_esp = scp->sc_sp;
853 	regs->tf_eip = scp->sc_pc;
854 	regs->tf_eflags = eflags;
855 
856 #if defined(COMPAT_43)
857 	if (scp->sc_onstack & 1)
858 		td->td_sigstk.ss_flags |= SS_ONSTACK;
859 	else
860 		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
861 #endif
862 	kern_sigprocmask(td, SIG_SETMASK, (sigset_t *)&scp->sc_mask, NULL,
863 	    SIGPROCMASK_OLD);
864 	return (EJUSTRETURN);
865 }
866 #endif /* COMPAT_43 */
867 
868 #ifdef COMPAT_FREEBSD4
869 /*
870  * MPSAFE
871  */
872 int
873 freebsd4_sigreturn(td, uap)
874 	struct thread *td;
875 	struct freebsd4_sigreturn_args /* {
876 		const ucontext4 *sigcntxp;
877 	} */ *uap;
878 {
879 	struct ucontext4 uc;
880 	struct trapframe *regs;
881 	struct ucontext4 *ucp;
882 	int cs, eflags, error;
883 	ksiginfo_t ksi;
884 
885 	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
886 	if (error != 0)
887 		return (error);
888 	ucp = &uc;
889 	regs = td->td_frame;
890 	eflags = ucp->uc_mcontext.mc_eflags;
891 	if (eflags & PSL_VM) {
892 		struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs;
893 		struct vm86_kernel *vm86;
894 
895 		/*
896 		 * if pcb_ext == 0 or vm86_inited == 0, the user hasn't
897 		 * set up the vm86 area, and we can't enter vm86 mode.
898 		 */
899 		if (td->td_pcb->pcb_ext == 0)
900 			return (EINVAL);
901 		vm86 = &td->td_pcb->pcb_ext->ext_vm86;
902 		if (vm86->vm86_inited == 0)
903 			return (EINVAL);
904 
905 		/* Go back to user mode if both flags are set. */
906 		if ((eflags & PSL_VIP) && (eflags & PSL_VIF)) {
907 			ksiginfo_init_trap(&ksi);
908 			ksi.ksi_signo = SIGBUS;
909 			ksi.ksi_code = BUS_OBJERR;
910 			ksi.ksi_addr = (void *)regs->tf_eip;
911 			trapsignal(td, &ksi);
912 		}
913 		if (vm86->vm86_has_vme) {
914 			eflags = (tf->tf_eflags & ~VME_USERCHANGE) |
915 			    (eflags & VME_USERCHANGE) | PSL_VM;
916 		} else {
917 			vm86->vm86_eflags = eflags;	/* save VIF, VIP */
918 			eflags = (tf->tf_eflags & ~VM_USERCHANGE) |
919 			    (eflags & VM_USERCHANGE) | PSL_VM;
920 		}
921 		bcopy(&ucp->uc_mcontext.mc_fs, tf, sizeof(struct trapframe));
922 		tf->tf_eflags = eflags;
923 		tf->tf_vm86_ds = tf->tf_ds;
924 		tf->tf_vm86_es = tf->tf_es;
925 		tf->tf_vm86_fs = tf->tf_fs;
926 		tf->tf_vm86_gs = ucp->uc_mcontext.mc_gs;
927 		tf->tf_ds = _udatasel;
928 		tf->tf_es = _udatasel;
929 		tf->tf_fs = _udatasel;
930 	} else {
931 		/*
932 		 * Don't allow users to change privileged or reserved flags.
933 		 */
934 		if (!EFL_SECURE(eflags, regs->tf_eflags)) {
935 			uprintf("pid %d (%s): freebsd4_sigreturn eflags = 0x%x\n",
936 			    td->td_proc->p_pid, td->td_name, eflags);
937 	    		return (EINVAL);
938 		}
939 
940 		/*
941 		 * Don't allow users to load a valid privileged %cs.  Let the
942 		 * hardware check for invalid selectors, excess privilege in
943 		 * other selectors, invalid %eip's and invalid %esp's.
944 		 */
945 		cs = ucp->uc_mcontext.mc_cs;
946 		if (!CS_SECURE(cs)) {
947 			uprintf("pid %d (%s): freebsd4_sigreturn cs = 0x%x\n",
948 			    td->td_proc->p_pid, td->td_name, cs);
949 			ksiginfo_init_trap(&ksi);
950 			ksi.ksi_signo = SIGBUS;
951 			ksi.ksi_code = BUS_OBJERR;
952 			ksi.ksi_trapno = T_PROTFLT;
953 			ksi.ksi_addr = (void *)regs->tf_eip;
954 			trapsignal(td, &ksi);
955 			return (EINVAL);
956 		}
957 
958 		bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(*regs));
959 	}
960 
961 #if defined(COMPAT_43)
962 	if (ucp->uc_mcontext.mc_onstack & 1)
963 		td->td_sigstk.ss_flags |= SS_ONSTACK;
964 	else
965 		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
966 #endif
967 	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
968 	return (EJUSTRETURN);
969 }
970 #endif	/* COMPAT_FREEBSD4 */
971 
972 /*
973  * MPSAFE
974  */
975 int
976 sys_sigreturn(td, uap)
977 	struct thread *td;
978 	struct sigreturn_args /* {
979 		const struct __ucontext *sigcntxp;
980 	} */ *uap;
981 {
982 	ucontext_t uc;
983 	struct proc *p;
984 	struct trapframe *regs;
985 	ucontext_t *ucp;
986 	char *xfpustate;
987 	size_t xfpustate_len;
988 	int cs, eflags, error, ret;
989 	ksiginfo_t ksi;
990 
991 	p = td->td_proc;
992 
993 	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
994 	if (error != 0)
995 		return (error);
996 	ucp = &uc;
997 	if ((ucp->uc_mcontext.mc_flags & ~_MC_FLAG_MASK) != 0) {
998 		uprintf("pid %d (%s): sigreturn mc_flags %x\n", p->p_pid,
999 		    td->td_name, ucp->uc_mcontext.mc_flags);
1000 		return (EINVAL);
1001 	}
1002 	regs = td->td_frame;
1003 	eflags = ucp->uc_mcontext.mc_eflags;
1004 	if (eflags & PSL_VM) {
1005 		struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs;
1006 		struct vm86_kernel *vm86;
1007 
1008 		/*
1009 		 * if pcb_ext == 0 or vm86_inited == 0, the user hasn't
1010 		 * set up the vm86 area, and we can't enter vm86 mode.
1011 		 */
1012 		if (td->td_pcb->pcb_ext == 0)
1013 			return (EINVAL);
1014 		vm86 = &td->td_pcb->pcb_ext->ext_vm86;
1015 		if (vm86->vm86_inited == 0)
1016 			return (EINVAL);
1017 
1018 		/* Go back to user mode if both flags are set. */
1019 		if ((eflags & PSL_VIP) && (eflags & PSL_VIF)) {
1020 			ksiginfo_init_trap(&ksi);
1021 			ksi.ksi_signo = SIGBUS;
1022 			ksi.ksi_code = BUS_OBJERR;
1023 			ksi.ksi_addr = (void *)regs->tf_eip;
1024 			trapsignal(td, &ksi);
1025 		}
1026 
1027 		if (vm86->vm86_has_vme) {
1028 			eflags = (tf->tf_eflags & ~VME_USERCHANGE) |
1029 			    (eflags & VME_USERCHANGE) | PSL_VM;
1030 		} else {
1031 			vm86->vm86_eflags = eflags;	/* save VIF, VIP */
1032 			eflags = (tf->tf_eflags & ~VM_USERCHANGE) |
1033 			    (eflags & VM_USERCHANGE) | PSL_VM;
1034 		}
1035 		bcopy(&ucp->uc_mcontext.mc_fs, tf, sizeof(struct trapframe));
1036 		tf->tf_eflags = eflags;
1037 		tf->tf_vm86_ds = tf->tf_ds;
1038 		tf->tf_vm86_es = tf->tf_es;
1039 		tf->tf_vm86_fs = tf->tf_fs;
1040 		tf->tf_vm86_gs = ucp->uc_mcontext.mc_gs;
1041 		tf->tf_ds = _udatasel;
1042 		tf->tf_es = _udatasel;
1043 		tf->tf_fs = _udatasel;
1044 	} else {
1045 		/*
1046 		 * Don't allow users to change privileged or reserved flags.
1047 		 */
1048 		if (!EFL_SECURE(eflags, regs->tf_eflags)) {
1049 			uprintf("pid %d (%s): sigreturn eflags = 0x%x\n",
1050 			    td->td_proc->p_pid, td->td_name, eflags);
1051 	    		return (EINVAL);
1052 		}
1053 
1054 		/*
1055 		 * Don't allow users to load a valid privileged %cs.  Let the
1056 		 * hardware check for invalid selectors, excess privilege in
1057 		 * other selectors, invalid %eip's and invalid %esp's.
1058 		 */
1059 		cs = ucp->uc_mcontext.mc_cs;
1060 		if (!CS_SECURE(cs)) {
1061 			uprintf("pid %d (%s): sigreturn cs = 0x%x\n",
1062 			    td->td_proc->p_pid, td->td_name, cs);
1063 			ksiginfo_init_trap(&ksi);
1064 			ksi.ksi_signo = SIGBUS;
1065 			ksi.ksi_code = BUS_OBJERR;
1066 			ksi.ksi_trapno = T_PROTFLT;
1067 			ksi.ksi_addr = (void *)regs->tf_eip;
1068 			trapsignal(td, &ksi);
1069 			return (EINVAL);
1070 		}
1071 
1072 		if ((uc.uc_mcontext.mc_flags & _MC_HASFPXSTATE) != 0) {
1073 			xfpustate_len = uc.uc_mcontext.mc_xfpustate_len;
1074 			if (xfpustate_len > cpu_max_ext_state_size -
1075 			    sizeof(union savefpu)) {
1076 				uprintf(
1077 			    "pid %d (%s): sigreturn xfpusave_len = 0x%zx\n",
1078 				    p->p_pid, td->td_name, xfpustate_len);
1079 				return (EINVAL);
1080 			}
1081 			xfpustate = __builtin_alloca(xfpustate_len);
1082 			error = copyin((const void *)uc.uc_mcontext.mc_xfpustate,
1083 			    xfpustate, xfpustate_len);
1084 			if (error != 0) {
1085 				uprintf(
1086 	"pid %d (%s): sigreturn copying xfpustate failed\n",
1087 				    p->p_pid, td->td_name);
1088 				return (error);
1089 			}
1090 		} else {
1091 			xfpustate = NULL;
1092 			xfpustate_len = 0;
1093 		}
1094 		ret = set_fpcontext(td, &ucp->uc_mcontext, xfpustate,
1095 		    xfpustate_len);
1096 		if (ret != 0)
1097 			return (ret);
1098 		bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(*regs));
1099 	}
1100 
1101 #if defined(COMPAT_43)
1102 	if (ucp->uc_mcontext.mc_onstack & 1)
1103 		td->td_sigstk.ss_flags |= SS_ONSTACK;
1104 	else
1105 		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
1106 #endif
1107 
1108 	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
1109 	return (EJUSTRETURN);
1110 }
1111 
1112 #ifdef COMPAT_43
1113 static void
1114 setup_priv_lcall_gate(struct proc *p)
1115 {
1116 	struct i386_ldt_args uap;
1117 	union descriptor desc;
1118 	u_int lcall_addr;
1119 
1120 	bzero(&uap, sizeof(uap));
1121 	uap.start = 0;
1122 	uap.num = 1;
1123 	lcall_addr = p->p_sysent->sv_psstrings - sz_lcall_tramp;
1124 	bzero(&desc, sizeof(desc));
1125 	desc.sd.sd_type = SDT_MEMERA;
1126 	desc.sd.sd_dpl = SEL_UPL;
1127 	desc.sd.sd_p = 1;
1128 	desc.sd.sd_def32 = 1;
1129 	desc.sd.sd_gran = 1;
1130 	desc.sd.sd_lolimit = 0xffff;
1131 	desc.sd.sd_hilimit = 0xf;
1132 	desc.sd.sd_lobase = lcall_addr;
1133 	desc.sd.sd_hibase = lcall_addr >> 24;
1134 	i386_set_ldt(curthread, &uap, &desc);
1135 }
1136 #endif
1137 
1138 /*
1139  * Reset registers to default values on exec.
1140  */
1141 void
1142 exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
1143 {
1144 	struct trapframe *regs;
1145 	struct pcb *pcb;
1146 	register_t saved_eflags;
1147 
1148 	regs = td->td_frame;
1149 	pcb = td->td_pcb;
1150 
1151 	/* Reset pc->pcb_gs and %gs before possibly invalidating it. */
1152 	pcb->pcb_gs = _udatasel;
1153 	load_gs(_udatasel);
1154 
1155 	mtx_lock_spin(&dt_lock);
1156 	if (td->td_proc->p_md.md_ldt != NULL)
1157 		user_ldt_free(td);
1158 	else
1159 		mtx_unlock_spin(&dt_lock);
1160 
1161 #ifdef COMPAT_43
1162 	if (td->td_proc->p_sysent->sv_psstrings !=
1163 	    elf32_freebsd_sysvec.sv_psstrings)
1164 		setup_priv_lcall_gate(td->td_proc);
1165 #endif
1166 
1167 	/*
1168 	 * Reset the fs and gs bases.  The values from the old address
1169 	 * space do not make sense for the new program.  In particular,
1170 	 * gsbase might be the TLS base for the old program but the new
1171 	 * program has no TLS now.
1172 	 */
1173 	set_fsbase(td, 0);
1174 	set_gsbase(td, 0);
1175 
1176 	/* Make sure edx is 0x0 on entry. Linux binaries depend on it. */
1177 	saved_eflags = regs->tf_eflags & PSL_T;
1178 	bzero((char *)regs, sizeof(struct trapframe));
1179 	regs->tf_eip = imgp->entry_addr;
1180 	regs->tf_esp = stack;
1181 	regs->tf_eflags = PSL_USER | saved_eflags;
1182 	regs->tf_ss = _udatasel;
1183 	regs->tf_ds = _udatasel;
1184 	regs->tf_es = _udatasel;
1185 	regs->tf_fs = _udatasel;
1186 	regs->tf_cs = _ucodesel;
1187 
1188 	/* PS_STRINGS value for BSD/OS binaries.  It is 0 for non-BSD/OS. */
1189 	regs->tf_ebx = imgp->ps_strings;
1190 
1191         /*
1192          * Reset the hardware debug registers if they were in use.
1193          * They won't have any meaning for the newly exec'd process.
1194          */
1195         if (pcb->pcb_flags & PCB_DBREGS) {
1196                 pcb->pcb_dr0 = 0;
1197                 pcb->pcb_dr1 = 0;
1198                 pcb->pcb_dr2 = 0;
1199                 pcb->pcb_dr3 = 0;
1200                 pcb->pcb_dr6 = 0;
1201                 pcb->pcb_dr7 = 0;
1202                 if (pcb == curpcb) {
1203 		        /*
1204 			 * Clear the debug registers on the running
1205 			 * CPU, otherwise they will end up affecting
1206 			 * the next process we switch to.
1207 			 */
1208 		        reset_dbregs();
1209                 }
1210 		pcb->pcb_flags &= ~PCB_DBREGS;
1211         }
1212 
1213 	pcb->pcb_initial_npxcw = __INITIAL_NPXCW__;
1214 
1215 	/*
1216 	 * Drop the FP state if we hold it, so that the process gets a
1217 	 * clean FP state if it uses the FPU again.
1218 	 */
1219 	fpstate_drop(td);
1220 }
1221 
1222 void
1223 cpu_setregs(void)
1224 {
1225 	unsigned int cr0;
1226 
1227 	cr0 = rcr0();
1228 
1229 	/*
1230 	 * CR0_MP, CR0_NE and CR0_TS are set for NPX (FPU) support:
1231 	 *
1232 	 * Prepare to trap all ESC (i.e., NPX) instructions and all WAIT
1233 	 * instructions.  We must set the CR0_MP bit and use the CR0_TS
1234 	 * bit to control the trap, because setting the CR0_EM bit does
1235 	 * not cause WAIT instructions to trap.  It's important to trap
1236 	 * WAIT instructions - otherwise the "wait" variants of no-wait
1237 	 * control instructions would degenerate to the "no-wait" variants
1238 	 * after FP context switches but work correctly otherwise.  It's
1239 	 * particularly important to trap WAITs when there is no NPX -
1240 	 * otherwise the "wait" variants would always degenerate.
1241 	 *
1242 	 * Try setting CR0_NE to get correct error reporting on 486DX's.
1243 	 * Setting it should fail or do nothing on lesser processors.
1244 	 */
1245 	cr0 |= CR0_MP | CR0_NE | CR0_TS | CR0_WP | CR0_AM;
1246 	load_cr0(cr0);
1247 	load_gs(_udatasel);
1248 }
1249 
1250 u_long bootdev;		/* not a struct cdev *- encoding is different */
1251 SYSCTL_ULONG(_machdep, OID_AUTO, guessed_bootdev,
1252 	CTLFLAG_RD, &bootdev, 0, "Maybe the Boot device (not in struct cdev *format)");
1253 
1254 static char bootmethod[16] = "BIOS";
1255 SYSCTL_STRING(_machdep, OID_AUTO, bootmethod, CTLFLAG_RD, bootmethod, 0,
1256     "System firmware boot method");
1257 
1258 /*
1259  * Initialize 386 and configure to run kernel
1260  */
1261 
1262 /*
1263  * Initialize segments & interrupt table
1264  */
1265 
1266 int _default_ldt;
1267 
1268 struct mtx dt_lock;			/* lock for GDT and LDT */
1269 
1270 union descriptor gdt0[NGDT];	/* initial global descriptor table */
1271 union descriptor *gdt = gdt0;	/* global descriptor table */
1272 
1273 union descriptor *ldt;		/* local descriptor table */
1274 
1275 static struct gate_descriptor idt0[NIDT];
1276 struct gate_descriptor *idt = &idt0[0];	/* interrupt descriptor table */
1277 
1278 static struct i386tss *dblfault_tss;
1279 static char *dblfault_stack;
1280 
1281 static struct i386tss common_tss0;
1282 
1283 vm_offset_t proc0kstack;
1284 
1285 /*
1286  * software prototypes -- in more palatable form.
1287  *
1288  * GCODE_SEL through GUDATA_SEL must be in this order for syscall/sysret
1289  * GUFS_SEL and GUGS_SEL must be in this order (swtch.s knows it)
1290  */
1291 struct soft_segment_descriptor gdt_segs[] = {
1292 /* GNULL_SEL	0 Null Descriptor */
1293 {	.ssd_base = 0x0,
1294 	.ssd_limit = 0x0,
1295 	.ssd_type = 0,
1296 	.ssd_dpl = SEL_KPL,
1297 	.ssd_p = 0,
1298 	.ssd_xx = 0, .ssd_xx1 = 0,
1299 	.ssd_def32 = 0,
1300 	.ssd_gran = 0		},
1301 /* GPRIV_SEL	1 SMP Per-Processor Private Data Descriptor */
1302 {	.ssd_base = 0x0,
1303 	.ssd_limit = 0xfffff,
1304 	.ssd_type = SDT_MEMRWA,
1305 	.ssd_dpl = SEL_KPL,
1306 	.ssd_p = 1,
1307 	.ssd_xx = 0, .ssd_xx1 = 0,
1308 	.ssd_def32 = 1,
1309 	.ssd_gran = 1		},
1310 /* GUFS_SEL	2 %fs Descriptor for user */
1311 {	.ssd_base = 0x0,
1312 	.ssd_limit = 0xfffff,
1313 	.ssd_type = SDT_MEMRWA,
1314 	.ssd_dpl = SEL_UPL,
1315 	.ssd_p = 1,
1316 	.ssd_xx = 0, .ssd_xx1 = 0,
1317 	.ssd_def32 = 1,
1318 	.ssd_gran = 1		},
1319 /* GUGS_SEL	3 %gs Descriptor for user */
1320 {	.ssd_base = 0x0,
1321 	.ssd_limit = 0xfffff,
1322 	.ssd_type = SDT_MEMRWA,
1323 	.ssd_dpl = SEL_UPL,
1324 	.ssd_p = 1,
1325 	.ssd_xx = 0, .ssd_xx1 = 0,
1326 	.ssd_def32 = 1,
1327 	.ssd_gran = 1		},
1328 /* GCODE_SEL	4 Code Descriptor for kernel */
1329 {	.ssd_base = 0x0,
1330 	.ssd_limit = 0xfffff,
1331 	.ssd_type = SDT_MEMERA,
1332 	.ssd_dpl = SEL_KPL,
1333 	.ssd_p = 1,
1334 	.ssd_xx = 0, .ssd_xx1 = 0,
1335 	.ssd_def32 = 1,
1336 	.ssd_gran = 1		},
1337 /* GDATA_SEL	5 Data Descriptor for kernel */
1338 {	.ssd_base = 0x0,
1339 	.ssd_limit = 0xfffff,
1340 	.ssd_type = SDT_MEMRWA,
1341 	.ssd_dpl = SEL_KPL,
1342 	.ssd_p = 1,
1343 	.ssd_xx = 0, .ssd_xx1 = 0,
1344 	.ssd_def32 = 1,
1345 	.ssd_gran = 1		},
1346 /* GUCODE_SEL	6 Code Descriptor for user */
1347 {	.ssd_base = 0x0,
1348 	.ssd_limit = 0xfffff,
1349 	.ssd_type = SDT_MEMERA,
1350 	.ssd_dpl = SEL_UPL,
1351 	.ssd_p = 1,
1352 	.ssd_xx = 0, .ssd_xx1 = 0,
1353 	.ssd_def32 = 1,
1354 	.ssd_gran = 1		},
1355 /* GUDATA_SEL	7 Data Descriptor for user */
1356 {	.ssd_base = 0x0,
1357 	.ssd_limit = 0xfffff,
1358 	.ssd_type = SDT_MEMRWA,
1359 	.ssd_dpl = SEL_UPL,
1360 	.ssd_p = 1,
1361 	.ssd_xx = 0, .ssd_xx1 = 0,
1362 	.ssd_def32 = 1,
1363 	.ssd_gran = 1		},
1364 /* GBIOSLOWMEM_SEL 8 BIOS access to realmode segment 0x40, must be #8 in GDT */
1365 {	.ssd_base = 0x400,
1366 	.ssd_limit = 0xfffff,
1367 	.ssd_type = SDT_MEMRWA,
1368 	.ssd_dpl = SEL_KPL,
1369 	.ssd_p = 1,
1370 	.ssd_xx = 0, .ssd_xx1 = 0,
1371 	.ssd_def32 = 1,
1372 	.ssd_gran = 1		},
1373 /* GPROC0_SEL	9 Proc 0 Tss Descriptor */
1374 {
1375 	.ssd_base = 0x0,
1376 	.ssd_limit = sizeof(struct i386tss)-1,
1377 	.ssd_type = SDT_SYS386TSS,
1378 	.ssd_dpl = 0,
1379 	.ssd_p = 1,
1380 	.ssd_xx = 0, .ssd_xx1 = 0,
1381 	.ssd_def32 = 0,
1382 	.ssd_gran = 0		},
1383 /* GLDT_SEL	10 LDT Descriptor */
1384 {	.ssd_base = 0,
1385 	.ssd_limit = sizeof(union descriptor) * NLDT - 1,
1386 	.ssd_type = SDT_SYSLDT,
1387 	.ssd_dpl = SEL_UPL,
1388 	.ssd_p = 1,
1389 	.ssd_xx = 0, .ssd_xx1 = 0,
1390 	.ssd_def32 = 0,
1391 	.ssd_gran = 0		},
1392 /* GUSERLDT_SEL	11 User LDT Descriptor per process */
1393 {	.ssd_base = 0,
1394 	.ssd_limit = (512 * sizeof(union descriptor)-1),
1395 	.ssd_type = SDT_SYSLDT,
1396 	.ssd_dpl = 0,
1397 	.ssd_p = 1,
1398 	.ssd_xx = 0, .ssd_xx1 = 0,
1399 	.ssd_def32 = 0,
1400 	.ssd_gran = 0		},
1401 /* GPANIC_SEL	12 Panic Tss Descriptor */
1402 {	.ssd_base = 0,
1403 	.ssd_limit = sizeof(struct i386tss)-1,
1404 	.ssd_type = SDT_SYS386TSS,
1405 	.ssd_dpl = 0,
1406 	.ssd_p = 1,
1407 	.ssd_xx = 0, .ssd_xx1 = 0,
1408 	.ssd_def32 = 0,
1409 	.ssd_gran = 0		},
1410 /* GBIOSCODE32_SEL 13 BIOS 32-bit interface (32bit Code) */
1411 {	.ssd_base = 0,
1412 	.ssd_limit = 0xfffff,
1413 	.ssd_type = SDT_MEMERA,
1414 	.ssd_dpl = 0,
1415 	.ssd_p = 1,
1416 	.ssd_xx = 0, .ssd_xx1 = 0,
1417 	.ssd_def32 = 0,
1418 	.ssd_gran = 1		},
1419 /* GBIOSCODE16_SEL 14 BIOS 32-bit interface (16bit Code) */
1420 {	.ssd_base = 0,
1421 	.ssd_limit = 0xfffff,
1422 	.ssd_type = SDT_MEMERA,
1423 	.ssd_dpl = 0,
1424 	.ssd_p = 1,
1425 	.ssd_xx = 0, .ssd_xx1 = 0,
1426 	.ssd_def32 = 0,
1427 	.ssd_gran = 1		},
1428 /* GBIOSDATA_SEL 15 BIOS 32-bit interface (Data) */
1429 {	.ssd_base = 0,
1430 	.ssd_limit = 0xfffff,
1431 	.ssd_type = SDT_MEMRWA,
1432 	.ssd_dpl = 0,
1433 	.ssd_p = 1,
1434 	.ssd_xx = 0, .ssd_xx1 = 0,
1435 	.ssd_def32 = 1,
1436 	.ssd_gran = 1		},
1437 /* GBIOSUTIL_SEL 16 BIOS 16-bit interface (Utility) */
1438 {	.ssd_base = 0,
1439 	.ssd_limit = 0xfffff,
1440 	.ssd_type = SDT_MEMRWA,
1441 	.ssd_dpl = 0,
1442 	.ssd_p = 1,
1443 	.ssd_xx = 0, .ssd_xx1 = 0,
1444 	.ssd_def32 = 0,
1445 	.ssd_gran = 1		},
1446 /* GBIOSARGS_SEL 17 BIOS 16-bit interface (Arguments) */
1447 {	.ssd_base = 0,
1448 	.ssd_limit = 0xfffff,
1449 	.ssd_type = SDT_MEMRWA,
1450 	.ssd_dpl = 0,
1451 	.ssd_p = 1,
1452 	.ssd_xx = 0, .ssd_xx1 = 0,
1453 	.ssd_def32 = 0,
1454 	.ssd_gran = 1		},
1455 /* GNDIS_SEL	18 NDIS Descriptor */
1456 {	.ssd_base = 0x0,
1457 	.ssd_limit = 0x0,
1458 	.ssd_type = 0,
1459 	.ssd_dpl = 0,
1460 	.ssd_p = 0,
1461 	.ssd_xx = 0, .ssd_xx1 = 0,
1462 	.ssd_def32 = 0,
1463 	.ssd_gran = 0		},
1464 };
1465 
1466 static struct soft_segment_descriptor ldt_segs[] = {
1467 	/* Null Descriptor - overwritten by call gate */
1468 {	.ssd_base = 0x0,
1469 	.ssd_limit = 0x0,
1470 	.ssd_type = 0,
1471 	.ssd_dpl = 0,
1472 	.ssd_p = 0,
1473 	.ssd_xx = 0, .ssd_xx1 = 0,
1474 	.ssd_def32 = 0,
1475 	.ssd_gran = 0		},
1476 	/* Null Descriptor - overwritten by call gate */
1477 {	.ssd_base = 0x0,
1478 	.ssd_limit = 0x0,
1479 	.ssd_type = 0,
1480 	.ssd_dpl = 0,
1481 	.ssd_p = 0,
1482 	.ssd_xx = 0, .ssd_xx1 = 0,
1483 	.ssd_def32 = 0,
1484 	.ssd_gran = 0		},
1485 	/* Null Descriptor - overwritten by call gate */
1486 {	.ssd_base = 0x0,
1487 	.ssd_limit = 0x0,
1488 	.ssd_type = 0,
1489 	.ssd_dpl = 0,
1490 	.ssd_p = 0,
1491 	.ssd_xx = 0, .ssd_xx1 = 0,
1492 	.ssd_def32 = 0,
1493 	.ssd_gran = 0		},
1494 	/* Code Descriptor for user */
1495 {	.ssd_base = 0x0,
1496 	.ssd_limit = 0xfffff,
1497 	.ssd_type = SDT_MEMERA,
1498 	.ssd_dpl = SEL_UPL,
1499 	.ssd_p = 1,
1500 	.ssd_xx = 0, .ssd_xx1 = 0,
1501 	.ssd_def32 = 1,
1502 	.ssd_gran = 1		},
1503 	/* Null Descriptor - overwritten by call gate */
1504 {	.ssd_base = 0x0,
1505 	.ssd_limit = 0x0,
1506 	.ssd_type = 0,
1507 	.ssd_dpl = 0,
1508 	.ssd_p = 0,
1509 	.ssd_xx = 0, .ssd_xx1 = 0,
1510 	.ssd_def32 = 0,
1511 	.ssd_gran = 0		},
1512 	/* Data Descriptor for user */
1513 {	.ssd_base = 0x0,
1514 	.ssd_limit = 0xfffff,
1515 	.ssd_type = SDT_MEMRWA,
1516 	.ssd_dpl = SEL_UPL,
1517 	.ssd_p = 1,
1518 	.ssd_xx = 0, .ssd_xx1 = 0,
1519 	.ssd_def32 = 1,
1520 	.ssd_gran = 1		},
1521 };
1522 
1523 uintptr_t setidt_disp;
1524 
1525 void
1526 setidt(int idx, inthand_t *func, int typ, int dpl, int selec)
1527 {
1528 	uintptr_t off;
1529 
1530 	off = func != NULL ? (uintptr_t)func + setidt_disp : 0;
1531 	setidt_nodisp(idx, off, typ, dpl, selec);
1532 }
1533 
1534 void
1535 setidt_nodisp(int idx, uintptr_t off, int typ, int dpl, int selec)
1536 {
1537 	struct gate_descriptor *ip;
1538 
1539 	ip = idt + idx;
1540 	ip->gd_looffset = off;
1541 	ip->gd_selector = selec;
1542 	ip->gd_stkcpy = 0;
1543 	ip->gd_xx = 0;
1544 	ip->gd_type = typ;
1545 	ip->gd_dpl = dpl;
1546 	ip->gd_p = 1;
1547 	ip->gd_hioffset = ((u_int)off) >> 16 ;
1548 }
1549 
1550 extern inthand_t
1551 	IDTVEC(div), IDTVEC(dbg), IDTVEC(nmi), IDTVEC(bpt), IDTVEC(ofl),
1552 	IDTVEC(bnd), IDTVEC(ill), IDTVEC(dna), IDTVEC(fpusegm),
1553 	IDTVEC(tss), IDTVEC(missing), IDTVEC(stk), IDTVEC(prot),
1554 	IDTVEC(page), IDTVEC(mchk), IDTVEC(rsvd), IDTVEC(fpu), IDTVEC(align),
1555 	IDTVEC(xmm),
1556 #ifdef KDTRACE_HOOKS
1557 	IDTVEC(dtrace_ret),
1558 #endif
1559 #ifdef XENHVM
1560 	IDTVEC(xen_intr_upcall),
1561 #endif
1562 	IDTVEC(int0x80_syscall);
1563 
1564 #ifdef DDB
1565 /*
1566  * Display the index and function name of any IDT entries that don't use
1567  * the default 'rsvd' entry point.
1568  */
1569 DB_SHOW_COMMAND(idt, db_show_idt)
1570 {
1571 	struct gate_descriptor *ip;
1572 	int idx;
1573 	uintptr_t func, func_trm;
1574 	bool trm;
1575 
1576 	ip = idt;
1577 	for (idx = 0; idx < NIDT && !db_pager_quit; idx++) {
1578 		if (ip->gd_type == SDT_SYSTASKGT) {
1579 			db_printf("%3d\t<TASK>\n", idx);
1580 		} else {
1581 			func = (ip->gd_hioffset << 16 | ip->gd_looffset);
1582 			if (func >= PMAP_TRM_MIN_ADDRESS) {
1583 				func_trm = func;
1584 				func -= setidt_disp;
1585 				trm = true;
1586 			} else
1587 				trm = false;
1588 			if (func != (uintptr_t)&IDTVEC(rsvd)) {
1589 				db_printf("%3d\t", idx);
1590 				db_printsym(func, DB_STGY_PROC);
1591 				if (trm)
1592 					db_printf(" (trampoline %#x)",
1593 					    func_trm);
1594 				db_printf("\n");
1595 			}
1596 		}
1597 		ip++;
1598 	}
1599 }
1600 
1601 /* Show privileged registers. */
1602 DB_SHOW_COMMAND(sysregs, db_show_sysregs)
1603 {
1604 	uint64_t idtr, gdtr;
1605 
1606 	idtr = ridt();
1607 	db_printf("idtr\t0x%08x/%04x\n",
1608 	    (u_int)(idtr >> 16), (u_int)idtr & 0xffff);
1609 	gdtr = rgdt();
1610 	db_printf("gdtr\t0x%08x/%04x\n",
1611 	    (u_int)(gdtr >> 16), (u_int)gdtr & 0xffff);
1612 	db_printf("ldtr\t0x%04x\n", rldt());
1613 	db_printf("tr\t0x%04x\n", rtr());
1614 	db_printf("cr0\t0x%08x\n", rcr0());
1615 	db_printf("cr2\t0x%08x\n", rcr2());
1616 	db_printf("cr3\t0x%08x\n", rcr3());
1617 	db_printf("cr4\t0x%08x\n", rcr4());
1618 	if (rcr4() & CR4_XSAVE)
1619 		db_printf("xcr0\t0x%016llx\n", rxcr(0));
1620 	if (amd_feature & (AMDID_NX | AMDID_LM))
1621 		db_printf("EFER\t0x%016llx\n", rdmsr(MSR_EFER));
1622 	if (cpu_feature2 & (CPUID2_VMX | CPUID2_SMX))
1623 		db_printf("FEATURES_CTL\t0x%016llx\n",
1624 		    rdmsr(MSR_IA32_FEATURE_CONTROL));
1625 	if ((cpu_vendor_id == CPU_VENDOR_INTEL ||
1626 	    cpu_vendor_id == CPU_VENDOR_AMD) && CPUID_TO_FAMILY(cpu_id) >= 6)
1627 		db_printf("DEBUG_CTL\t0x%016llx\n", rdmsr(MSR_DEBUGCTLMSR));
1628 	if (cpu_feature & CPUID_PAT)
1629 		db_printf("PAT\t0x%016llx\n", rdmsr(MSR_PAT));
1630 }
1631 
1632 DB_SHOW_COMMAND(dbregs, db_show_dbregs)
1633 {
1634 
1635 	db_printf("dr0\t0x%08x\n", rdr0());
1636 	db_printf("dr1\t0x%08x\n", rdr1());
1637 	db_printf("dr2\t0x%08x\n", rdr2());
1638 	db_printf("dr3\t0x%08x\n", rdr3());
1639 	db_printf("dr6\t0x%08x\n", rdr6());
1640 	db_printf("dr7\t0x%08x\n", rdr7());
1641 }
1642 
1643 DB_SHOW_COMMAND(frame, db_show_frame)
1644 {
1645 	struct trapframe *frame;
1646 
1647 	frame = have_addr ? (struct trapframe *)addr : curthread->td_frame;
1648 	printf("ss %#x esp %#x efl %#x cs %#x eip %#x\n",
1649 	    frame->tf_ss, frame->tf_esp, frame->tf_eflags, frame->tf_cs,
1650 	    frame->tf_eip);
1651 	printf("err %#x trapno %d\n", frame->tf_err, frame->tf_trapno);
1652 	printf("ds %#x es %#x fs %#x\n",
1653 	    frame->tf_ds, frame->tf_es, frame->tf_fs);
1654 	printf("eax %#x ecx %#x edx %#x ebx %#x\n",
1655 	    frame->tf_eax, frame->tf_ecx, frame->tf_edx, frame->tf_ebx);
1656 	printf("ebp %#x esi %#x edi %#x\n",
1657 	    frame->tf_ebp, frame->tf_esi, frame->tf_edi);
1658 
1659 }
1660 #endif
1661 
1662 void
1663 sdtossd(sd, ssd)
1664 	struct segment_descriptor *sd;
1665 	struct soft_segment_descriptor *ssd;
1666 {
1667 	ssd->ssd_base  = (sd->sd_hibase << 24) | sd->sd_lobase;
1668 	ssd->ssd_limit = (sd->sd_hilimit << 16) | sd->sd_lolimit;
1669 	ssd->ssd_type  = sd->sd_type;
1670 	ssd->ssd_dpl   = sd->sd_dpl;
1671 	ssd->ssd_p     = sd->sd_p;
1672 	ssd->ssd_def32 = sd->sd_def32;
1673 	ssd->ssd_gran  = sd->sd_gran;
1674 }
1675 
1676 static int
1677 add_physmap_entry(uint64_t base, uint64_t length, vm_paddr_t *physmap,
1678     int *physmap_idxp)
1679 {
1680 	uint64_t lim, ign;
1681 	int i, insert_idx, physmap_idx;
1682 
1683 	physmap_idx = *physmap_idxp;
1684 
1685 	if (length == 0)
1686 		return (1);
1687 
1688 	lim = 0x100000000;					/*  4G */
1689 	if (pae_mode && above4g_allow)
1690 		lim = above24g_allow ? -1ULL : 0x600000000;	/* 24G */
1691 	if (base >= lim) {
1692 		printf("%uK of memory above %uGB ignored, pae %d "
1693 		    "above4g_allow %d above24g_allow %d\n",
1694 		    (u_int)(length / 1024), (u_int)(lim >> 30), pae_mode,
1695 		    above4g_allow, above24g_allow);
1696 		return (1);
1697 	}
1698 	if (base + length >= lim) {
1699 		ign = base + length - lim;
1700 		length -= ign;
1701 		printf("%uK of memory above %uGB ignored, pae %d "
1702 		    "above4g_allow %d above24g_allow %d\n",
1703 		    (u_int)(ign / 1024), (u_int)(lim >> 30), pae_mode,
1704 		    above4g_allow, above24g_allow);
1705 	}
1706 
1707 	/*
1708 	 * Find insertion point while checking for overlap.  Start off by
1709 	 * assuming the new entry will be added to the end.
1710 	 */
1711 	insert_idx = physmap_idx + 2;
1712 	for (i = 0; i <= physmap_idx; i += 2) {
1713 		if (base < physmap[i + 1]) {
1714 			if (base + length <= physmap[i]) {
1715 				insert_idx = i;
1716 				break;
1717 			}
1718 			if (boothowto & RB_VERBOSE)
1719 				printf(
1720 		    "Overlapping memory regions, ignoring second region\n");
1721 			return (1);
1722 		}
1723 	}
1724 
1725 	/* See if we can prepend to the next entry. */
1726 	if (insert_idx <= physmap_idx && base + length == physmap[insert_idx]) {
1727 		physmap[insert_idx] = base;
1728 		return (1);
1729 	}
1730 
1731 	/* See if we can append to the previous entry. */
1732 	if (insert_idx > 0 && base == physmap[insert_idx - 1]) {
1733 		physmap[insert_idx - 1] += length;
1734 		return (1);
1735 	}
1736 
1737 	physmap_idx += 2;
1738 	*physmap_idxp = physmap_idx;
1739 	if (physmap_idx == PHYSMAP_SIZE) {
1740 		printf(
1741 		"Too many segments in the physical address map, giving up\n");
1742 		return (0);
1743 	}
1744 
1745 	/*
1746 	 * Move the last 'N' entries down to make room for the new
1747 	 * entry if needed.
1748 	 */
1749 	for (i = physmap_idx; i > insert_idx; i -= 2) {
1750 		physmap[i] = physmap[i - 2];
1751 		physmap[i + 1] = physmap[i - 1];
1752 	}
1753 
1754 	/* Insert the new entry. */
1755 	physmap[insert_idx] = base;
1756 	physmap[insert_idx + 1] = base + length;
1757 	return (1);
1758 }
1759 
1760 static int
1761 add_smap_entry(struct bios_smap *smap, vm_paddr_t *physmap, int *physmap_idxp)
1762 {
1763 	if (boothowto & RB_VERBOSE)
1764 		printf("SMAP type=%02x base=%016llx len=%016llx\n",
1765 		    smap->type, smap->base, smap->length);
1766 
1767 	if (smap->type != SMAP_TYPE_MEMORY)
1768 		return (1);
1769 
1770 	return (add_physmap_entry(smap->base, smap->length, physmap,
1771 	    physmap_idxp));
1772 }
1773 
1774 static void
1775 add_smap_entries(struct bios_smap *smapbase, vm_paddr_t *physmap,
1776     int *physmap_idxp)
1777 {
1778 	struct bios_smap *smap, *smapend;
1779 	u_int32_t smapsize;
1780 	/*
1781 	 * Memory map from INT 15:E820.
1782 	 *
1783 	 * subr_module.c says:
1784 	 * "Consumer may safely assume that size value precedes data."
1785 	 * ie: an int32_t immediately precedes SMAP.
1786 	 */
1787 	smapsize = *((u_int32_t *)smapbase - 1);
1788 	smapend = (struct bios_smap *)((uintptr_t)smapbase + smapsize);
1789 
1790 	for (smap = smapbase; smap < smapend; smap++)
1791 		if (!add_smap_entry(smap, physmap, physmap_idxp))
1792 			break;
1793 }
1794 
1795 static void
1796 basemem_setup(void)
1797 {
1798 
1799 	if (basemem > 640) {
1800 		printf("Preposterous BIOS basemem of %uK, truncating to 640K\n",
1801 			basemem);
1802 		basemem = 640;
1803 	}
1804 
1805 	pmap_basemem_setup(basemem);
1806 }
1807 
1808 /*
1809  * Populate the (physmap) array with base/bound pairs describing the
1810  * available physical memory in the system, then test this memory and
1811  * build the phys_avail array describing the actually-available memory.
1812  *
1813  * If we cannot accurately determine the physical memory map, then use
1814  * value from the 0xE801 call, and failing that, the RTC.
1815  *
1816  * Total memory size may be set by the kernel environment variable
1817  * hw.physmem or the compile-time define MAXMEM.
1818  *
1819  * XXX first should be vm_paddr_t.
1820  */
1821 static void
1822 getmemsize(int first)
1823 {
1824 	int has_smap, off, physmap_idx, pa_indx, da_indx;
1825 	u_long memtest;
1826 	vm_paddr_t physmap[PHYSMAP_SIZE];
1827 	quad_t dcons_addr, dcons_size, physmem_tunable;
1828 	int hasbrokenint12, i, res;
1829 	u_int extmem;
1830 	struct vm86frame vmf;
1831 	struct vm86context vmc;
1832 	vm_paddr_t pa;
1833 	struct bios_smap *smap, *smapbase;
1834 	caddr_t kmdp;
1835 
1836 	has_smap = 0;
1837 	bzero(&vmf, sizeof(vmf));
1838 	bzero(physmap, sizeof(physmap));
1839 	basemem = 0;
1840 
1841 	/*
1842 	 * Tell the physical memory allocator about pages used to store
1843 	 * the kernel and preloaded data.  See kmem_bootstrap_free().
1844 	 */
1845 	vm_phys_add_seg((vm_paddr_t)KERNLOAD, trunc_page(first));
1846 
1847 	TUNABLE_INT_FETCH("hw.above4g_allow", &above4g_allow);
1848 	TUNABLE_INT_FETCH("hw.above24g_allow", &above24g_allow);
1849 
1850 	/*
1851 	 * Check if the loader supplied an SMAP memory map.  If so,
1852 	 * use that and do not make any VM86 calls.
1853 	 */
1854 	physmap_idx = 0;
1855 	kmdp = preload_search_by_type("elf kernel");
1856 	if (kmdp == NULL)
1857 		kmdp = preload_search_by_type("elf32 kernel");
1858 	smapbase = (struct bios_smap *)preload_search_info(kmdp,
1859 	    MODINFO_METADATA | MODINFOMD_SMAP);
1860 	if (smapbase != NULL) {
1861 		add_smap_entries(smapbase, physmap, &physmap_idx);
1862 		has_smap = 1;
1863 		goto have_smap;
1864 	}
1865 
1866 	/*
1867 	 * Some newer BIOSes have a broken INT 12H implementation
1868 	 * which causes a kernel panic immediately.  In this case, we
1869 	 * need use the SMAP to determine the base memory size.
1870 	 */
1871 	hasbrokenint12 = 0;
1872 	TUNABLE_INT_FETCH("hw.hasbrokenint12", &hasbrokenint12);
1873 	if (hasbrokenint12 == 0) {
1874 		/* Use INT12 to determine base memory size. */
1875 		vm86_intcall(0x12, &vmf);
1876 		basemem = vmf.vmf_ax;
1877 		basemem_setup();
1878 	}
1879 
1880 	/*
1881 	 * Fetch the memory map with INT 15:E820.  Map page 1 R/W into
1882 	 * the kernel page table so we can use it as a buffer.  The
1883 	 * kernel will unmap this page later.
1884 	 */
1885 	vmc.npages = 0;
1886 	smap = (void *)vm86_addpage(&vmc, 1, PMAP_MAP_LOW + ptoa(1));
1887 	res = vm86_getptr(&vmc, (vm_offset_t)smap, &vmf.vmf_es, &vmf.vmf_di);
1888 	KASSERT(res != 0, ("vm86_getptr() failed: address not found"));
1889 
1890 	vmf.vmf_ebx = 0;
1891 	do {
1892 		vmf.vmf_eax = 0xE820;
1893 		vmf.vmf_edx = SMAP_SIG;
1894 		vmf.vmf_ecx = sizeof(struct bios_smap);
1895 		i = vm86_datacall(0x15, &vmf, &vmc);
1896 		if (i || vmf.vmf_eax != SMAP_SIG)
1897 			break;
1898 		has_smap = 1;
1899 		if (!add_smap_entry(smap, physmap, &physmap_idx))
1900 			break;
1901 	} while (vmf.vmf_ebx != 0);
1902 
1903 have_smap:
1904 	/*
1905 	 * If we didn't fetch the "base memory" size from INT12,
1906 	 * figure it out from the SMAP (or just guess).
1907 	 */
1908 	if (basemem == 0) {
1909 		for (i = 0; i <= physmap_idx; i += 2) {
1910 			if (physmap[i] == 0x00000000) {
1911 				basemem = physmap[i + 1] / 1024;
1912 				break;
1913 			}
1914 		}
1915 
1916 		/* XXX: If we couldn't find basemem from SMAP, just guess. */
1917 		if (basemem == 0)
1918 			basemem = 640;
1919 		basemem_setup();
1920 	}
1921 
1922 	if (physmap[1] != 0)
1923 		goto physmap_done;
1924 
1925 	/*
1926 	 * If we failed to find an SMAP, figure out the extended
1927 	 * memory size.  We will then build a simple memory map with
1928 	 * two segments, one for "base memory" and the second for
1929 	 * "extended memory".  Note that "extended memory" starts at a
1930 	 * physical address of 1MB and that both basemem and extmem
1931 	 * are in units of 1KB.
1932 	 *
1933 	 * First, try to fetch the extended memory size via INT 15:E801.
1934 	 */
1935 	vmf.vmf_ax = 0xE801;
1936 	if (vm86_intcall(0x15, &vmf) == 0) {
1937 		extmem = vmf.vmf_cx + vmf.vmf_dx * 64;
1938 	} else {
1939 		/*
1940 		 * If INT15:E801 fails, this is our last ditch effort
1941 		 * to determine the extended memory size.  Currently
1942 		 * we prefer the RTC value over INT15:88.
1943 		 */
1944 #if 0
1945 		vmf.vmf_ah = 0x88;
1946 		vm86_intcall(0x15, &vmf);
1947 		extmem = vmf.vmf_ax;
1948 #else
1949 		extmem = rtcin(RTC_EXTLO) + (rtcin(RTC_EXTHI) << 8);
1950 #endif
1951 	}
1952 
1953 	/*
1954 	 * Special hack for chipsets that still remap the 384k hole when
1955 	 * there's 16MB of memory - this really confuses people that
1956 	 * are trying to use bus mastering ISA controllers with the
1957 	 * "16MB limit"; they only have 16MB, but the remapping puts
1958 	 * them beyond the limit.
1959 	 *
1960 	 * If extended memory is between 15-16MB (16-17MB phys address range),
1961 	 *	chop it to 15MB.
1962 	 */
1963 	if ((extmem > 15 * 1024) && (extmem < 16 * 1024))
1964 		extmem = 15 * 1024;
1965 
1966 	physmap[0] = 0;
1967 	physmap[1] = basemem * 1024;
1968 	physmap_idx = 2;
1969 	physmap[physmap_idx] = 0x100000;
1970 	physmap[physmap_idx + 1] = physmap[physmap_idx] + extmem * 1024;
1971 
1972 physmap_done:
1973 	/*
1974 	 * Now, physmap contains a map of physical memory.
1975 	 */
1976 
1977 #ifdef SMP
1978 	/* make hole for AP bootstrap code */
1979 	alloc_ap_trampoline(physmap, &physmap_idx);
1980 #endif
1981 
1982 	/*
1983 	 * Maxmem isn't the "maximum memory", it's one larger than the
1984 	 * highest page of the physical address space.  It should be
1985 	 * called something like "Maxphyspage".  We may adjust this
1986 	 * based on ``hw.physmem'' and the results of the memory test.
1987 	 *
1988 	 * This is especially confusing when it is much larger than the
1989 	 * memory size and is displayed as "realmem".
1990 	 */
1991 	Maxmem = atop(physmap[physmap_idx + 1]);
1992 
1993 #ifdef MAXMEM
1994 	Maxmem = MAXMEM / 4;
1995 #endif
1996 
1997 	if (TUNABLE_QUAD_FETCH("hw.physmem", &physmem_tunable))
1998 		Maxmem = atop(physmem_tunable);
1999 
2000 	/*
2001 	 * If we have an SMAP, don't allow MAXMEM or hw.physmem to extend
2002 	 * the amount of memory in the system.
2003 	 */
2004 	if (has_smap && Maxmem > atop(physmap[physmap_idx + 1]))
2005 		Maxmem = atop(physmap[physmap_idx + 1]);
2006 
2007 	/*
2008 	 * The boot memory test is disabled by default, as it takes a
2009 	 * significant amount of time on large-memory systems, and is
2010 	 * unfriendly to virtual machines as it unnecessarily touches all
2011 	 * pages.
2012 	 *
2013 	 * A general name is used as the code may be extended to support
2014 	 * additional tests beyond the current "page present" test.
2015 	 */
2016 	memtest = 0;
2017 	TUNABLE_ULONG_FETCH("hw.memtest.tests", &memtest);
2018 
2019 	if (atop(physmap[physmap_idx + 1]) != Maxmem &&
2020 	    (boothowto & RB_VERBOSE))
2021 		printf("Physical memory use set to %ldK\n", Maxmem * 4);
2022 
2023 	/*
2024 	 * If Maxmem has been increased beyond what the system has detected,
2025 	 * extend the last memory segment to the new limit.
2026 	 */
2027 	if (atop(physmap[physmap_idx + 1]) < Maxmem)
2028 		physmap[physmap_idx + 1] = ptoa((vm_paddr_t)Maxmem);
2029 
2030 	/* call pmap initialization to make new kernel address space */
2031 	pmap_bootstrap(first);
2032 
2033 	/*
2034 	 * Size up each available chunk of physical memory.
2035 	 */
2036 	physmap[0] = PAGE_SIZE;		/* mask off page 0 */
2037 	pa_indx = 0;
2038 	da_indx = 1;
2039 	phys_avail[pa_indx++] = physmap[0];
2040 	phys_avail[pa_indx] = physmap[0];
2041 	dump_avail[da_indx] = physmap[0];
2042 
2043 	/*
2044 	 * Get dcons buffer address
2045 	 */
2046 	if (getenv_quad("dcons.addr", &dcons_addr) == 0 ||
2047 	    getenv_quad("dcons.size", &dcons_size) == 0)
2048 		dcons_addr = 0;
2049 
2050 	/*
2051 	 * physmap is in bytes, so when converting to page boundaries,
2052 	 * round up the start address and round down the end address.
2053 	 */
2054 	for (i = 0; i <= physmap_idx; i += 2) {
2055 		vm_paddr_t end;
2056 
2057 		end = ptoa((vm_paddr_t)Maxmem);
2058 		if (physmap[i + 1] < end)
2059 			end = trunc_page(physmap[i + 1]);
2060 		for (pa = round_page(physmap[i]); pa < end; pa += PAGE_SIZE) {
2061 			int tmp, page_bad, full;
2062 			int *ptr;
2063 
2064 			full = FALSE;
2065 			/*
2066 			 * block out kernel memory as not available.
2067 			 */
2068 			if (pa >= KERNLOAD && pa < first)
2069 				goto do_dump_avail;
2070 
2071 			/*
2072 			 * block out dcons buffer
2073 			 */
2074 			if (dcons_addr > 0
2075 			    && pa >= trunc_page(dcons_addr)
2076 			    && pa < dcons_addr + dcons_size)
2077 				goto do_dump_avail;
2078 
2079 			page_bad = FALSE;
2080 			if (memtest == 0)
2081 				goto skip_memtest;
2082 
2083 			/*
2084 			 * map page into kernel: valid, read/write,non-cacheable
2085 			 */
2086 			ptr = (int *)pmap_cmap3(pa, PG_V | PG_RW | PG_N);
2087 
2088 			tmp = *(int *)ptr;
2089 			/*
2090 			 * Test for alternating 1's and 0's
2091 			 */
2092 			*(volatile int *)ptr = 0xaaaaaaaa;
2093 			if (*(volatile int *)ptr != 0xaaaaaaaa)
2094 				page_bad = TRUE;
2095 			/*
2096 			 * Test for alternating 0's and 1's
2097 			 */
2098 			*(volatile int *)ptr = 0x55555555;
2099 			if (*(volatile int *)ptr != 0x55555555)
2100 				page_bad = TRUE;
2101 			/*
2102 			 * Test for all 1's
2103 			 */
2104 			*(volatile int *)ptr = 0xffffffff;
2105 			if (*(volatile int *)ptr != 0xffffffff)
2106 				page_bad = TRUE;
2107 			/*
2108 			 * Test for all 0's
2109 			 */
2110 			*(volatile int *)ptr = 0x0;
2111 			if (*(volatile int *)ptr != 0x0)
2112 				page_bad = TRUE;
2113 			/*
2114 			 * Restore original value.
2115 			 */
2116 			*(int *)ptr = tmp;
2117 
2118 skip_memtest:
2119 			/*
2120 			 * Adjust array of valid/good pages.
2121 			 */
2122 			if (page_bad == TRUE)
2123 				continue;
2124 			/*
2125 			 * If this good page is a continuation of the
2126 			 * previous set of good pages, then just increase
2127 			 * the end pointer. Otherwise start a new chunk.
2128 			 * Note that "end" points one higher than end,
2129 			 * making the range >= start and < end.
2130 			 * If we're also doing a speculative memory
2131 			 * test and we at or past the end, bump up Maxmem
2132 			 * so that we keep going. The first bad page
2133 			 * will terminate the loop.
2134 			 */
2135 			if (phys_avail[pa_indx] == pa) {
2136 				phys_avail[pa_indx] += PAGE_SIZE;
2137 			} else {
2138 				pa_indx++;
2139 				if (pa_indx == PHYS_AVAIL_ARRAY_END) {
2140 					printf(
2141 		"Too many holes in the physical address space, giving up\n");
2142 					pa_indx--;
2143 					full = TRUE;
2144 					goto do_dump_avail;
2145 				}
2146 				phys_avail[pa_indx++] = pa;	/* start */
2147 				phys_avail[pa_indx] = pa + PAGE_SIZE; /* end */
2148 			}
2149 			physmem++;
2150 do_dump_avail:
2151 			if (dump_avail[da_indx] == pa) {
2152 				dump_avail[da_indx] += PAGE_SIZE;
2153 			} else {
2154 				da_indx++;
2155 				if (da_indx == DUMP_AVAIL_ARRAY_END) {
2156 					da_indx--;
2157 					goto do_next;
2158 				}
2159 				dump_avail[da_indx++] = pa;	/* start */
2160 				dump_avail[da_indx] = pa + PAGE_SIZE; /* end */
2161 			}
2162 do_next:
2163 			if (full)
2164 				break;
2165 		}
2166 	}
2167 	pmap_cmap3(0, 0);
2168 
2169 	/*
2170 	 * XXX
2171 	 * The last chunk must contain at least one page plus the message
2172 	 * buffer to avoid complicating other code (message buffer address
2173 	 * calculation, etc.).
2174 	 */
2175 	while (phys_avail[pa_indx - 1] + PAGE_SIZE +
2176 	    round_page(msgbufsize) >= phys_avail[pa_indx]) {
2177 		physmem -= atop(phys_avail[pa_indx] - phys_avail[pa_indx - 1]);
2178 		phys_avail[pa_indx--] = 0;
2179 		phys_avail[pa_indx--] = 0;
2180 	}
2181 
2182 	Maxmem = atop(phys_avail[pa_indx]);
2183 
2184 	/* Trim off space for the message buffer. */
2185 	phys_avail[pa_indx] -= round_page(msgbufsize);
2186 
2187 	/* Map the message buffer. */
2188 	for (off = 0; off < round_page(msgbufsize); off += PAGE_SIZE)
2189 		pmap_kenter((vm_offset_t)msgbufp + off, phys_avail[pa_indx] +
2190 		    off);
2191 }
2192 
2193 static void
2194 i386_kdb_init(void)
2195 {
2196 #ifdef DDB
2197 	db_fetch_ksymtab(bootinfo.bi_symtab, bootinfo.bi_esymtab);
2198 #endif
2199 	kdb_init();
2200 #ifdef KDB
2201 	if (boothowto & RB_KDB)
2202 		kdb_enter(KDB_WHY_BOOTFLAGS, "Boot flags requested debugger");
2203 #endif
2204 }
2205 
2206 static void
2207 fixup_idt(void)
2208 {
2209 	struct gate_descriptor *ip;
2210 	uintptr_t off;
2211 	int x;
2212 
2213 	for (x = 0; x < NIDT; x++) {
2214 		ip = &idt[x];
2215 		if (ip->gd_type != SDT_SYS386IGT &&
2216 		    ip->gd_type != SDT_SYS386TGT)
2217 			continue;
2218 		off = ip->gd_looffset + (((u_int)ip->gd_hioffset) << 16);
2219 		KASSERT(off >= (uintptr_t)start_exceptions &&
2220 		    off < (uintptr_t)end_exceptions,
2221 		    ("IDT[%d] type %d off %#x", x, ip->gd_type, off));
2222 		off += setidt_disp;
2223 		MPASS(off >= PMAP_TRM_MIN_ADDRESS &&
2224 		    off < PMAP_TRM_MAX_ADDRESS);
2225 		ip->gd_looffset = off;
2226 		ip->gd_hioffset = off >> 16;
2227 	}
2228 }
2229 
2230 static void
2231 i386_setidt1(void)
2232 {
2233 	int x;
2234 
2235 	/* exceptions */
2236 	for (x = 0; x < NIDT; x++)
2237 		setidt(x, &IDTVEC(rsvd), SDT_SYS386IGT, SEL_KPL,
2238 		    GSEL(GCODE_SEL, SEL_KPL));
2239 	setidt(IDT_DE, &IDTVEC(div), SDT_SYS386IGT, SEL_KPL,
2240 	    GSEL(GCODE_SEL, SEL_KPL));
2241 	setidt(IDT_DB, &IDTVEC(dbg), SDT_SYS386IGT, SEL_KPL,
2242 	    GSEL(GCODE_SEL, SEL_KPL));
2243 	setidt(IDT_NMI, &IDTVEC(nmi), SDT_SYS386IGT, SEL_KPL,
2244 	    GSEL(GCODE_SEL, SEL_KPL));
2245 	setidt(IDT_BP, &IDTVEC(bpt), SDT_SYS386IGT, SEL_UPL,
2246 	    GSEL(GCODE_SEL, SEL_KPL));
2247 	setidt(IDT_OF, &IDTVEC(ofl), SDT_SYS386IGT, SEL_UPL,
2248 	    GSEL(GCODE_SEL, SEL_KPL));
2249 	setidt(IDT_BR, &IDTVEC(bnd), SDT_SYS386IGT, SEL_KPL,
2250 	    GSEL(GCODE_SEL, SEL_KPL));
2251 	setidt(IDT_UD, &IDTVEC(ill), SDT_SYS386IGT, SEL_KPL,
2252 	    GSEL(GCODE_SEL, SEL_KPL));
2253 	setidt(IDT_NM, &IDTVEC(dna), SDT_SYS386IGT, SEL_KPL,
2254 	    GSEL(GCODE_SEL, SEL_KPL));
2255 	setidt(IDT_DF, 0, SDT_SYSTASKGT, SEL_KPL, GSEL(GPANIC_SEL,
2256 	    SEL_KPL));
2257 	setidt(IDT_FPUGP, &IDTVEC(fpusegm), SDT_SYS386IGT,
2258 	    SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
2259 	setidt(IDT_TS, &IDTVEC(tss), SDT_SYS386IGT, SEL_KPL,
2260 	    GSEL(GCODE_SEL, SEL_KPL));
2261 	setidt(IDT_NP, &IDTVEC(missing), SDT_SYS386IGT, SEL_KPL,
2262 	    GSEL(GCODE_SEL, SEL_KPL));
2263 	setidt(IDT_SS, &IDTVEC(stk), SDT_SYS386IGT, SEL_KPL,
2264 	    GSEL(GCODE_SEL, SEL_KPL));
2265 	setidt(IDT_GP, &IDTVEC(prot), SDT_SYS386IGT, SEL_KPL,
2266 	    GSEL(GCODE_SEL, SEL_KPL));
2267 	setidt(IDT_PF, &IDTVEC(page), SDT_SYS386IGT, SEL_KPL,
2268 	    GSEL(GCODE_SEL, SEL_KPL));
2269 	setidt(IDT_MF, &IDTVEC(fpu), SDT_SYS386IGT, SEL_KPL,
2270 	    GSEL(GCODE_SEL, SEL_KPL));
2271 	setidt(IDT_AC, &IDTVEC(align), SDT_SYS386IGT, SEL_KPL,
2272 	    GSEL(GCODE_SEL, SEL_KPL));
2273 	setidt(IDT_MC, &IDTVEC(mchk), SDT_SYS386IGT, SEL_KPL,
2274 	    GSEL(GCODE_SEL, SEL_KPL));
2275 	setidt(IDT_XF, &IDTVEC(xmm), SDT_SYS386IGT, SEL_KPL,
2276 	    GSEL(GCODE_SEL, SEL_KPL));
2277 	setidt(IDT_SYSCALL, &IDTVEC(int0x80_syscall),
2278 	    SDT_SYS386IGT, SEL_UPL, GSEL(GCODE_SEL, SEL_KPL));
2279 #ifdef KDTRACE_HOOKS
2280 	setidt(IDT_DTRACE_RET, &IDTVEC(dtrace_ret),
2281 	    SDT_SYS386IGT, SEL_UPL, GSEL(GCODE_SEL, SEL_KPL));
2282 #endif
2283 #ifdef XENHVM
2284 	setidt(IDT_EVTCHN, &IDTVEC(xen_intr_upcall),
2285 	    SDT_SYS386IGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
2286 #endif
2287 }
2288 
2289 static void
2290 i386_setidt2(void)
2291 {
2292 
2293 	setidt(IDT_UD, &IDTVEC(ill), SDT_SYS386IGT, SEL_KPL,
2294 	    GSEL(GCODE_SEL, SEL_KPL));
2295 	setidt(IDT_GP, &IDTVEC(prot), SDT_SYS386IGT, SEL_KPL,
2296 	    GSEL(GCODE_SEL, SEL_KPL));
2297 }
2298 
2299 #if defined(DEV_ISA) && !defined(DEV_ATPIC)
2300 static void
2301 i386_setidt3(void)
2302 {
2303 
2304 	setidt(IDT_IO_INTS + 7, IDTVEC(spuriousint),
2305 	    SDT_SYS386IGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
2306 	setidt(IDT_IO_INTS + 15, IDTVEC(spuriousint),
2307 	    SDT_SYS386IGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
2308 }
2309 #endif
2310 
2311 register_t
2312 init386(int first)
2313 {
2314 	struct region_descriptor r_gdt, r_idt;	/* table descriptors */
2315 	int gsel_tss, metadata_missing, x, pa;
2316 	struct pcpu *pc;
2317 	struct xstate_hdr *xhdr;
2318 	caddr_t kmdp;
2319 	vm_offset_t addend;
2320 	size_t ucode_len;
2321 	int late_console;
2322 
2323 	thread0.td_kstack = proc0kstack;
2324 	thread0.td_kstack_pages = TD0_KSTACK_PAGES;
2325 
2326 	/*
2327  	 * This may be done better later if it gets more high level
2328  	 * components in it. If so just link td->td_proc here.
2329 	 */
2330 	proc_linkup0(&proc0, &thread0);
2331 
2332 	if (bootinfo.bi_modulep) {
2333 		metadata_missing = 0;
2334 		addend = (vm_paddr_t)bootinfo.bi_modulep < KERNBASE ?
2335 		    PMAP_MAP_LOW : 0;
2336 		preload_metadata = (caddr_t)bootinfo.bi_modulep + addend;
2337 		preload_bootstrap_relocate(addend);
2338 	} else {
2339 		metadata_missing = 1;
2340 	}
2341 
2342 	if (bootinfo.bi_envp != 0) {
2343 		addend = (vm_paddr_t)bootinfo.bi_envp < KERNBASE ?
2344 		    PMAP_MAP_LOW : 0;
2345 		init_static_kenv((char *)bootinfo.bi_envp + addend, 0);
2346 	} else {
2347 		init_static_kenv(NULL, 0);
2348 	}
2349 
2350 	/*
2351 	 * Re-evaluate CPU features if we loaded a microcode update.
2352 	 */
2353 	ucode_len = ucode_load_bsp(first);
2354 	if (ucode_len != 0) {
2355 		identify_cpu();
2356 		first = roundup2(first + ucode_len, PAGE_SIZE);
2357 	}
2358 
2359 	identify_hypervisor();
2360 
2361 	/* Init basic tunables, hz etc */
2362 	init_param1();
2363 
2364 	/*
2365 	 * Make gdt memory segments.  All segments cover the full 4GB
2366 	 * of address space and permissions are enforced at page level.
2367 	 */
2368 	gdt_segs[GCODE_SEL].ssd_limit = atop(0 - 1);
2369 	gdt_segs[GDATA_SEL].ssd_limit = atop(0 - 1);
2370 	gdt_segs[GUCODE_SEL].ssd_limit = atop(0 - 1);
2371 	gdt_segs[GUDATA_SEL].ssd_limit = atop(0 - 1);
2372 	gdt_segs[GUFS_SEL].ssd_limit = atop(0 - 1);
2373 	gdt_segs[GUGS_SEL].ssd_limit = atop(0 - 1);
2374 
2375 	pc = &__pcpu[0];
2376 	gdt_segs[GPRIV_SEL].ssd_limit = atop(0 - 1);
2377 	gdt_segs[GPRIV_SEL].ssd_base = (int)pc;
2378 	gdt_segs[GPROC0_SEL].ssd_base = (int)&common_tss0;
2379 
2380 	for (x = 0; x < NGDT; x++)
2381 		ssdtosd(&gdt_segs[x], &gdt0[x].sd);
2382 
2383 	r_gdt.rd_limit = NGDT * sizeof(gdt0[0]) - 1;
2384 	r_gdt.rd_base =  (int)gdt0;
2385 	mtx_init(&dt_lock, "descriptor tables", NULL, MTX_SPIN);
2386 	lgdt(&r_gdt);
2387 
2388 	pcpu_init(pc, 0, sizeof(struct pcpu));
2389 	for (pa = first; pa < first + DPCPU_SIZE; pa += PAGE_SIZE)
2390 		pmap_kenter(pa, pa);
2391 	dpcpu_init((void *)first, 0);
2392 	first += DPCPU_SIZE;
2393 	PCPU_SET(prvspace, pc);
2394 	PCPU_SET(curthread, &thread0);
2395 	/* Non-late cninit() and printf() can be moved up to here. */
2396 
2397 	/*
2398 	 * Initialize mutexes.
2399 	 *
2400 	 * icu_lock: in order to allow an interrupt to occur in a critical
2401 	 * 	     section, to set pcpu->ipending (etc...) properly, we
2402 	 *	     must be able to get the icu lock, so it can't be
2403 	 *	     under witness.
2404 	 */
2405 	mutex_init();
2406 	mtx_init(&icu_lock, "icu", NULL, MTX_SPIN | MTX_NOWITNESS | MTX_NOPROFILE);
2407 
2408 	i386_setidt1();
2409 
2410 	r_idt.rd_limit = sizeof(idt0) - 1;
2411 	r_idt.rd_base = (int) idt;
2412 	lidt(&r_idt);
2413 
2414 	/*
2415 	 * Initialize the clock before the console so that console
2416 	 * initialization can use DELAY().
2417 	 */
2418 	clock_init();
2419 
2420 	finishidentcpu();	/* Final stage of CPU initialization */
2421 	i386_setidt2();
2422 	pmap_set_nx();
2423 	initializecpu();	/* Initialize CPU registers */
2424 	initializecpucache();
2425 
2426 	/* pointer to selector slot for %fs/%gs */
2427 	PCPU_SET(fsgs_gdt, &gdt[GUFS_SEL].sd);
2428 
2429 	/* Initialize the tss (except for the final esp0) early for vm86. */
2430 	common_tss0.tss_esp0 = thread0.td_kstack + thread0.td_kstack_pages *
2431 	    PAGE_SIZE - VM86_STACK_SPACE;
2432 	common_tss0.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
2433 	common_tss0.tss_ioopt = sizeof(struct i386tss) << 16;
2434 	gsel_tss = GSEL(GPROC0_SEL, SEL_KPL);
2435 	PCPU_SET(tss_gdt, &gdt[GPROC0_SEL].sd);
2436 	PCPU_SET(common_tssd, *PCPU_GET(tss_gdt));
2437 	ltr(gsel_tss);
2438 
2439 	/* Initialize the PIC early for vm86 calls. */
2440 #ifdef DEV_ISA
2441 #ifdef DEV_ATPIC
2442 	elcr_probe();
2443 	atpic_startup();
2444 #else
2445 	/* Reset and mask the atpics and leave them shut down. */
2446 	atpic_reset();
2447 
2448 	/*
2449 	 * Point the ICU spurious interrupt vectors at the APIC spurious
2450 	 * interrupt handler.
2451 	 */
2452 	i386_setidt3();
2453 #endif
2454 #endif
2455 
2456 	/*
2457 	 * The console and kdb should be initialized even earlier than here,
2458 	 * but some console drivers don't work until after getmemsize().
2459 	 * Default to late console initialization to support these drivers.
2460 	 * This loses mainly printf()s in getmemsize() and early debugging.
2461 	 */
2462 	late_console = 1;
2463 	TUNABLE_INT_FETCH("debug.late_console", &late_console);
2464 	if (!late_console) {
2465 		cninit();
2466 		i386_kdb_init();
2467 	}
2468 
2469 	kmdp = preload_search_by_type("elf kernel");
2470 	link_elf_ireloc(kmdp);
2471 
2472 	vm86_initialize();
2473 	getmemsize(first);
2474 	init_param2(physmem);
2475 
2476 	/* now running on new page tables, configured,and u/iom is accessible */
2477 
2478 	if (late_console)
2479 		cninit();
2480 
2481 	if (metadata_missing)
2482 		printf("WARNING: loader(8) metadata is missing!\n");
2483 
2484 	if (late_console)
2485 		i386_kdb_init();
2486 
2487 	msgbufinit(msgbufp, msgbufsize);
2488 	npxinit(true);
2489 	/*
2490 	 * Set up thread0 pcb after npxinit calculated pcb + fpu save
2491 	 * area size.  Zero out the extended state header in fpu save
2492 	 * area.
2493 	 */
2494 	thread0.td_pcb = get_pcb_td(&thread0);
2495 	thread0.td_pcb->pcb_save = get_pcb_user_save_td(&thread0);
2496 	bzero(get_pcb_user_save_td(&thread0), cpu_max_ext_state_size);
2497 	if (use_xsave) {
2498 		xhdr = (struct xstate_hdr *)(get_pcb_user_save_td(&thread0) +
2499 		    1);
2500 		xhdr->xstate_bv = xsave_mask;
2501 	}
2502 	PCPU_SET(curpcb, thread0.td_pcb);
2503 	/* Move esp0 in the tss to its final place. */
2504 	/* Note: -16 is so we can grow the trapframe if we came from vm86 */
2505 	common_tss0.tss_esp0 = (vm_offset_t)thread0.td_pcb - VM86_STACK_SPACE;
2506 	PCPU_SET(kesp0, common_tss0.tss_esp0);
2507 	gdt[GPROC0_SEL].sd.sd_type = SDT_SYS386TSS;	/* clear busy bit */
2508 	ltr(gsel_tss);
2509 
2510 	/* transfer to user mode */
2511 
2512 	_ucodesel = GSEL(GUCODE_SEL, SEL_UPL);
2513 	_udatasel = GSEL(GUDATA_SEL, SEL_UPL);
2514 
2515 	/* setup proc 0's pcb */
2516 	thread0.td_pcb->pcb_flags = 0;
2517 	thread0.td_pcb->pcb_cr3 = pmap_get_kcr3();
2518 	thread0.td_pcb->pcb_ext = 0;
2519 	thread0.td_frame = &proc0_tf;
2520 
2521 	cpu_probe_amdc1e();
2522 
2523 #ifdef FDT
2524 	x86_init_fdt();
2525 #endif
2526 
2527 	/* Location of kernel stack for locore */
2528 	return ((register_t)thread0.td_pcb);
2529 }
2530 
2531 static void
2532 machdep_init_trampoline(void)
2533 {
2534 	struct region_descriptor r_gdt, r_idt;
2535 	struct i386tss *tss;
2536 	char *copyout_buf, *trampoline, *tramp_stack_base;
2537 	int x;
2538 
2539 	gdt = pmap_trm_alloc(sizeof(union descriptor) * NGDT * mp_ncpus,
2540 	    M_NOWAIT | M_ZERO);
2541 	bcopy(gdt0, gdt, sizeof(union descriptor) * NGDT);
2542 	r_gdt.rd_limit = NGDT * sizeof(gdt[0]) - 1;
2543 	r_gdt.rd_base = (int)gdt;
2544 	lgdt(&r_gdt);
2545 
2546 	tss = pmap_trm_alloc(sizeof(struct i386tss) * mp_ncpus,
2547 	    M_NOWAIT | M_ZERO);
2548 	bcopy(&common_tss0, tss, sizeof(struct i386tss));
2549 	gdt[GPROC0_SEL].sd.sd_lobase = (int)tss;
2550 	gdt[GPROC0_SEL].sd.sd_hibase = (u_int)tss >> 24;
2551 	gdt[GPROC0_SEL].sd.sd_type = SDT_SYS386TSS;
2552 
2553 	PCPU_SET(fsgs_gdt, &gdt[GUFS_SEL].sd);
2554 	PCPU_SET(tss_gdt, &gdt[GPROC0_SEL].sd);
2555 	PCPU_SET(common_tssd, *PCPU_GET(tss_gdt));
2556 	PCPU_SET(common_tssp, tss);
2557 	ltr(GSEL(GPROC0_SEL, SEL_KPL));
2558 
2559 	trampoline = pmap_trm_alloc(end_exceptions - start_exceptions,
2560 	    M_NOWAIT);
2561 	bcopy(start_exceptions, trampoline, end_exceptions - start_exceptions);
2562 	tramp_stack_base = pmap_trm_alloc(TRAMP_STACK_SZ, M_NOWAIT);
2563 	PCPU_SET(trampstk, (uintptr_t)tramp_stack_base + TRAMP_STACK_SZ -
2564 	    VM86_STACK_SPACE);
2565 	tss[0].tss_esp0 = PCPU_GET(trampstk);
2566 
2567 	idt = pmap_trm_alloc(sizeof(idt0), M_NOWAIT | M_ZERO);
2568 	bcopy(idt0, idt, sizeof(idt0));
2569 
2570 	/* Re-initialize new IDT since the handlers were relocated */
2571 	setidt_disp = trampoline - start_exceptions;
2572 	fixup_idt();
2573 
2574 	r_idt.rd_limit = sizeof(struct gate_descriptor) * NIDT - 1;
2575 	r_idt.rd_base = (int)idt;
2576 	lidt(&r_idt);
2577 
2578 	/* dblfault TSS */
2579 	dblfault_tss = pmap_trm_alloc(sizeof(struct i386tss), M_NOWAIT | M_ZERO);
2580 	dblfault_stack = pmap_trm_alloc(PAGE_SIZE, M_NOWAIT);
2581 	dblfault_tss->tss_esp = dblfault_tss->tss_esp0 =
2582 	    dblfault_tss->tss_esp1 = dblfault_tss->tss_esp2 =
2583 	    (int)dblfault_stack + PAGE_SIZE;
2584 	dblfault_tss->tss_ss = dblfault_tss->tss_ss0 = dblfault_tss->tss_ss1 =
2585 	    dblfault_tss->tss_ss2 = GSEL(GDATA_SEL, SEL_KPL);
2586 	dblfault_tss->tss_cr3 = pmap_get_kcr3();
2587 	dblfault_tss->tss_eip = (int)dblfault_handler;
2588 	dblfault_tss->tss_eflags = PSL_KERNEL;
2589 	dblfault_tss->tss_ds = dblfault_tss->tss_es =
2590 	    dblfault_tss->tss_gs = GSEL(GDATA_SEL, SEL_KPL);
2591 	dblfault_tss->tss_fs = GSEL(GPRIV_SEL, SEL_KPL);
2592 	dblfault_tss->tss_cs = GSEL(GCODE_SEL, SEL_KPL);
2593 	dblfault_tss->tss_ldt = GSEL(GLDT_SEL, SEL_KPL);
2594 	gdt[GPANIC_SEL].sd.sd_lobase = (int)dblfault_tss;
2595 	gdt[GPANIC_SEL].sd.sd_hibase = (u_int)dblfault_tss >> 24;
2596 
2597 	/* make ldt memory segments */
2598 	ldt = pmap_trm_alloc(sizeof(union descriptor) * NLDT,
2599 	    M_NOWAIT | M_ZERO);
2600 	gdt[GLDT_SEL].sd.sd_lobase = (int)ldt;
2601 	gdt[GLDT_SEL].sd.sd_hibase = (u_int)ldt >> 24;
2602 	ldt_segs[LUCODE_SEL].ssd_limit = atop(0 - 1);
2603 	ldt_segs[LUDATA_SEL].ssd_limit = atop(0 - 1);
2604 	for (x = 0; x < nitems(ldt_segs); x++)
2605 		ssdtosd(&ldt_segs[x], &ldt[x].sd);
2606 
2607 	_default_ldt = GSEL(GLDT_SEL, SEL_KPL);
2608 	lldt(_default_ldt);
2609 	PCPU_SET(currentldt, _default_ldt);
2610 
2611 	copyout_buf = pmap_trm_alloc(TRAMP_COPYOUT_SZ, M_NOWAIT);
2612 	PCPU_SET(copyout_buf, copyout_buf);
2613 	copyout_init_tramp();
2614 }
2615 SYSINIT(vm_mem, SI_SUB_VM, SI_ORDER_SECOND, machdep_init_trampoline, NULL);
2616 
2617 #ifdef COMPAT_43
2618 static void
2619 i386_setup_lcall_gate(void)
2620 {
2621 	struct sysentvec *sv;
2622 	struct user_segment_descriptor desc;
2623 	u_int lcall_addr;
2624 
2625 	sv = &elf32_freebsd_sysvec;
2626 	lcall_addr = (uintptr_t)sv->sv_psstrings - sz_lcall_tramp;
2627 
2628 	bzero(&desc, sizeof(desc));
2629 	desc.sd_type = SDT_MEMERA;
2630 	desc.sd_dpl = SEL_UPL;
2631 	desc.sd_p = 1;
2632 	desc.sd_def32 = 1;
2633 	desc.sd_gran = 1;
2634 	desc.sd_lolimit = 0xffff;
2635 	desc.sd_hilimit = 0xf;
2636 	desc.sd_lobase = lcall_addr;
2637 	desc.sd_hibase = lcall_addr >> 24;
2638 	bcopy(&desc, &ldt[LSYS5CALLS_SEL], sizeof(desc));
2639 }
2640 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_ANY, i386_setup_lcall_gate, NULL);
2641 #endif
2642 
2643 void
2644 cpu_pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
2645 {
2646 
2647 	pcpu->pc_acpi_id = 0xffffffff;
2648 }
2649 
2650 static int
2651 smap_sysctl_handler(SYSCTL_HANDLER_ARGS)
2652 {
2653 	struct bios_smap *smapbase;
2654 	struct bios_smap_xattr smap;
2655 	caddr_t kmdp;
2656 	uint32_t *smapattr;
2657 	int count, error, i;
2658 
2659 	/* Retrieve the system memory map from the loader. */
2660 	kmdp = preload_search_by_type("elf kernel");
2661 	if (kmdp == NULL)
2662 		kmdp = preload_search_by_type("elf32 kernel");
2663 	smapbase = (struct bios_smap *)preload_search_info(kmdp,
2664 	    MODINFO_METADATA | MODINFOMD_SMAP);
2665 	if (smapbase == NULL)
2666 		return (0);
2667 	smapattr = (uint32_t *)preload_search_info(kmdp,
2668 	    MODINFO_METADATA | MODINFOMD_SMAP_XATTR);
2669 	count = *((u_int32_t *)smapbase - 1) / sizeof(*smapbase);
2670 	error = 0;
2671 	for (i = 0; i < count; i++) {
2672 		smap.base = smapbase[i].base;
2673 		smap.length = smapbase[i].length;
2674 		smap.type = smapbase[i].type;
2675 		if (smapattr != NULL)
2676 			smap.xattr = smapattr[i];
2677 		else
2678 			smap.xattr = 0;
2679 		error = SYSCTL_OUT(req, &smap, sizeof(smap));
2680 	}
2681 	return (error);
2682 }
2683 SYSCTL_PROC(_machdep, OID_AUTO, smap, CTLTYPE_OPAQUE|CTLFLAG_RD, NULL, 0,
2684     smap_sysctl_handler, "S,bios_smap_xattr", "Raw BIOS SMAP data");
2685 
2686 void
2687 spinlock_enter(void)
2688 {
2689 	struct thread *td;
2690 	register_t flags;
2691 
2692 	td = curthread;
2693 	if (td->td_md.md_spinlock_count == 0) {
2694 		flags = intr_disable();
2695 		td->td_md.md_spinlock_count = 1;
2696 		td->td_md.md_saved_flags = flags;
2697 	} else
2698 		td->td_md.md_spinlock_count++;
2699 	critical_enter();
2700 }
2701 
2702 void
2703 spinlock_exit(void)
2704 {
2705 	struct thread *td;
2706 	register_t flags;
2707 
2708 	td = curthread;
2709 	critical_exit();
2710 	flags = td->td_md.md_saved_flags;
2711 	td->td_md.md_spinlock_count--;
2712 	if (td->td_md.md_spinlock_count == 0)
2713 		intr_restore(flags);
2714 }
2715 
2716 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
2717 static void f00f_hack(void *unused);
2718 SYSINIT(f00f_hack, SI_SUB_INTRINSIC, SI_ORDER_FIRST, f00f_hack, NULL);
2719 
2720 static void
2721 f00f_hack(void *unused)
2722 {
2723 	struct region_descriptor r_idt;
2724 	struct gate_descriptor *new_idt;
2725 	vm_offset_t tmp;
2726 
2727 	if (!has_f00f_bug)
2728 		return;
2729 
2730 	GIANT_REQUIRED;
2731 
2732 	printf("Intel Pentium detected, installing workaround for F00F bug\n");
2733 
2734 	tmp = (vm_offset_t)pmap_trm_alloc(PAGE_SIZE * 3, M_NOWAIT | M_ZERO);
2735 	if (tmp == 0)
2736 		panic("kmem_malloc returned 0");
2737 	tmp = round_page(tmp);
2738 
2739 	/* Put the problematic entry (#6) at the end of the lower page. */
2740 	new_idt = (struct gate_descriptor *)
2741 	    (tmp + PAGE_SIZE - 7 * sizeof(struct gate_descriptor));
2742 	bcopy(idt, new_idt, sizeof(idt0));
2743 	r_idt.rd_base = (u_int)new_idt;
2744 	r_idt.rd_limit = sizeof(idt0) - 1;
2745 	lidt(&r_idt);
2746 	/* SMP machines do not need the F00F hack. */
2747 	idt = new_idt;
2748 	pmap_protect(kernel_pmap, tmp, tmp + PAGE_SIZE, VM_PROT_READ);
2749 }
2750 #endif /* defined(I586_CPU) && !NO_F00F_HACK */
2751 
2752 /*
2753  * Construct a PCB from a trapframe. This is called from kdb_trap() where
2754  * we want to start a backtrace from the function that caused us to enter
2755  * the debugger. We have the context in the trapframe, but base the trace
2756  * on the PCB. The PCB doesn't have to be perfect, as long as it contains
2757  * enough for a backtrace.
2758  */
2759 void
2760 makectx(struct trapframe *tf, struct pcb *pcb)
2761 {
2762 
2763 	pcb->pcb_edi = tf->tf_edi;
2764 	pcb->pcb_esi = tf->tf_esi;
2765 	pcb->pcb_ebp = tf->tf_ebp;
2766 	pcb->pcb_ebx = tf->tf_ebx;
2767 	pcb->pcb_eip = tf->tf_eip;
2768 	pcb->pcb_esp = (ISPL(tf->tf_cs)) ? tf->tf_esp : (int)(tf + 1) - 8;
2769 	pcb->pcb_gs = rgs();
2770 }
2771 
2772 int
2773 ptrace_set_pc(struct thread *td, u_long addr)
2774 {
2775 
2776 	td->td_frame->tf_eip = addr;
2777 	return (0);
2778 }
2779 
2780 int
2781 ptrace_single_step(struct thread *td)
2782 {
2783 
2784 	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
2785 	if ((td->td_frame->tf_eflags & PSL_T) == 0) {
2786 		td->td_frame->tf_eflags |= PSL_T;
2787 		td->td_dbgflags |= TDB_STEP;
2788 	}
2789 	return (0);
2790 }
2791 
2792 int
2793 ptrace_clear_single_step(struct thread *td)
2794 {
2795 
2796 	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
2797 	td->td_frame->tf_eflags &= ~PSL_T;
2798 	td->td_dbgflags &= ~TDB_STEP;
2799 	return (0);
2800 }
2801 
2802 int
2803 fill_regs(struct thread *td, struct reg *regs)
2804 {
2805 	struct pcb *pcb;
2806 	struct trapframe *tp;
2807 
2808 	tp = td->td_frame;
2809 	pcb = td->td_pcb;
2810 	regs->r_gs = pcb->pcb_gs;
2811 	return (fill_frame_regs(tp, regs));
2812 }
2813 
2814 int
2815 fill_frame_regs(struct trapframe *tp, struct reg *regs)
2816 {
2817 
2818 	regs->r_fs = tp->tf_fs;
2819 	regs->r_es = tp->tf_es;
2820 	regs->r_ds = tp->tf_ds;
2821 	regs->r_edi = tp->tf_edi;
2822 	regs->r_esi = tp->tf_esi;
2823 	regs->r_ebp = tp->tf_ebp;
2824 	regs->r_ebx = tp->tf_ebx;
2825 	regs->r_edx = tp->tf_edx;
2826 	regs->r_ecx = tp->tf_ecx;
2827 	regs->r_eax = tp->tf_eax;
2828 	regs->r_eip = tp->tf_eip;
2829 	regs->r_cs = tp->tf_cs;
2830 	regs->r_eflags = tp->tf_eflags;
2831 	regs->r_esp = tp->tf_esp;
2832 	regs->r_ss = tp->tf_ss;
2833 	regs->r_err = 0;
2834 	regs->r_trapno = 0;
2835 	return (0);
2836 }
2837 
2838 int
2839 set_regs(struct thread *td, struct reg *regs)
2840 {
2841 	struct pcb *pcb;
2842 	struct trapframe *tp;
2843 
2844 	tp = td->td_frame;
2845 	if (!EFL_SECURE(regs->r_eflags, tp->tf_eflags) ||
2846 	    !CS_SECURE(regs->r_cs))
2847 		return (EINVAL);
2848 	pcb = td->td_pcb;
2849 	tp->tf_fs = regs->r_fs;
2850 	tp->tf_es = regs->r_es;
2851 	tp->tf_ds = regs->r_ds;
2852 	tp->tf_edi = regs->r_edi;
2853 	tp->tf_esi = regs->r_esi;
2854 	tp->tf_ebp = regs->r_ebp;
2855 	tp->tf_ebx = regs->r_ebx;
2856 	tp->tf_edx = regs->r_edx;
2857 	tp->tf_ecx = regs->r_ecx;
2858 	tp->tf_eax = regs->r_eax;
2859 	tp->tf_eip = regs->r_eip;
2860 	tp->tf_cs = regs->r_cs;
2861 	tp->tf_eflags = regs->r_eflags;
2862 	tp->tf_esp = regs->r_esp;
2863 	tp->tf_ss = regs->r_ss;
2864 	pcb->pcb_gs = regs->r_gs;
2865 	return (0);
2866 }
2867 
2868 int
2869 fill_fpregs(struct thread *td, struct fpreg *fpregs)
2870 {
2871 
2872 	KASSERT(td == curthread || TD_IS_SUSPENDED(td) ||
2873 	    P_SHOULDSTOP(td->td_proc),
2874 	    ("not suspended thread %p", td));
2875 	npxgetregs(td);
2876 	if (cpu_fxsr)
2877 		npx_fill_fpregs_xmm(&get_pcb_user_save_td(td)->sv_xmm,
2878 		    (struct save87 *)fpregs);
2879 	else
2880 		bcopy(&get_pcb_user_save_td(td)->sv_87, fpregs,
2881 		    sizeof(*fpregs));
2882 	return (0);
2883 }
2884 
2885 int
2886 set_fpregs(struct thread *td, struct fpreg *fpregs)
2887 {
2888 
2889 	critical_enter();
2890 	if (cpu_fxsr)
2891 		npx_set_fpregs_xmm((struct save87 *)fpregs,
2892 		    &get_pcb_user_save_td(td)->sv_xmm);
2893 	else
2894 		bcopy(fpregs, &get_pcb_user_save_td(td)->sv_87,
2895 		    sizeof(*fpregs));
2896 	npxuserinited(td);
2897 	critical_exit();
2898 	return (0);
2899 }
2900 
2901 /*
2902  * Get machine context.
2903  */
2904 int
2905 get_mcontext(struct thread *td, mcontext_t *mcp, int flags)
2906 {
2907 	struct trapframe *tp;
2908 	struct segment_descriptor *sdp;
2909 
2910 	tp = td->td_frame;
2911 
2912 	PROC_LOCK(curthread->td_proc);
2913 	mcp->mc_onstack = sigonstack(tp->tf_esp);
2914 	PROC_UNLOCK(curthread->td_proc);
2915 	mcp->mc_gs = td->td_pcb->pcb_gs;
2916 	mcp->mc_fs = tp->tf_fs;
2917 	mcp->mc_es = tp->tf_es;
2918 	mcp->mc_ds = tp->tf_ds;
2919 	mcp->mc_edi = tp->tf_edi;
2920 	mcp->mc_esi = tp->tf_esi;
2921 	mcp->mc_ebp = tp->tf_ebp;
2922 	mcp->mc_isp = tp->tf_isp;
2923 	mcp->mc_eflags = tp->tf_eflags;
2924 	if (flags & GET_MC_CLEAR_RET) {
2925 		mcp->mc_eax = 0;
2926 		mcp->mc_edx = 0;
2927 		mcp->mc_eflags &= ~PSL_C;
2928 	} else {
2929 		mcp->mc_eax = tp->tf_eax;
2930 		mcp->mc_edx = tp->tf_edx;
2931 	}
2932 	mcp->mc_ebx = tp->tf_ebx;
2933 	mcp->mc_ecx = tp->tf_ecx;
2934 	mcp->mc_eip = tp->tf_eip;
2935 	mcp->mc_cs = tp->tf_cs;
2936 	mcp->mc_esp = tp->tf_esp;
2937 	mcp->mc_ss = tp->tf_ss;
2938 	mcp->mc_len = sizeof(*mcp);
2939 	get_fpcontext(td, mcp, NULL, 0);
2940 	sdp = &td->td_pcb->pcb_fsd;
2941 	mcp->mc_fsbase = sdp->sd_hibase << 24 | sdp->sd_lobase;
2942 	sdp = &td->td_pcb->pcb_gsd;
2943 	mcp->mc_gsbase = sdp->sd_hibase << 24 | sdp->sd_lobase;
2944 	mcp->mc_flags = 0;
2945 	mcp->mc_xfpustate = 0;
2946 	mcp->mc_xfpustate_len = 0;
2947 	bzero(mcp->mc_spare2, sizeof(mcp->mc_spare2));
2948 	return (0);
2949 }
2950 
2951 /*
2952  * Set machine context.
2953  *
2954  * However, we don't set any but the user modifiable flags, and we won't
2955  * touch the cs selector.
2956  */
2957 int
2958 set_mcontext(struct thread *td, mcontext_t *mcp)
2959 {
2960 	struct trapframe *tp;
2961 	char *xfpustate;
2962 	int eflags, ret;
2963 
2964 	tp = td->td_frame;
2965 	if (mcp->mc_len != sizeof(*mcp) ||
2966 	    (mcp->mc_flags & ~_MC_FLAG_MASK) != 0)
2967 		return (EINVAL);
2968 	eflags = (mcp->mc_eflags & PSL_USERCHANGE) |
2969 	    (tp->tf_eflags & ~PSL_USERCHANGE);
2970 	if (mcp->mc_flags & _MC_HASFPXSTATE) {
2971 		if (mcp->mc_xfpustate_len > cpu_max_ext_state_size -
2972 		    sizeof(union savefpu))
2973 			return (EINVAL);
2974 		xfpustate = __builtin_alloca(mcp->mc_xfpustate_len);
2975 		ret = copyin((void *)mcp->mc_xfpustate, xfpustate,
2976 		    mcp->mc_xfpustate_len);
2977 		if (ret != 0)
2978 			return (ret);
2979 	} else
2980 		xfpustate = NULL;
2981 	ret = set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len);
2982 	if (ret != 0)
2983 		return (ret);
2984 	tp->tf_fs = mcp->mc_fs;
2985 	tp->tf_es = mcp->mc_es;
2986 	tp->tf_ds = mcp->mc_ds;
2987 	tp->tf_edi = mcp->mc_edi;
2988 	tp->tf_esi = mcp->mc_esi;
2989 	tp->tf_ebp = mcp->mc_ebp;
2990 	tp->tf_ebx = mcp->mc_ebx;
2991 	tp->tf_edx = mcp->mc_edx;
2992 	tp->tf_ecx = mcp->mc_ecx;
2993 	tp->tf_eax = mcp->mc_eax;
2994 	tp->tf_eip = mcp->mc_eip;
2995 	tp->tf_eflags = eflags;
2996 	tp->tf_esp = mcp->mc_esp;
2997 	tp->tf_ss = mcp->mc_ss;
2998 	td->td_pcb->pcb_gs = mcp->mc_gs;
2999 	return (0);
3000 }
3001 
3002 static void
3003 get_fpcontext(struct thread *td, mcontext_t *mcp, char *xfpusave,
3004     size_t xfpusave_len)
3005 {
3006 	size_t max_len, len;
3007 
3008 	mcp->mc_ownedfp = npxgetregs(td);
3009 	bcopy(get_pcb_user_save_td(td), &mcp->mc_fpstate[0],
3010 	    sizeof(mcp->mc_fpstate));
3011 	mcp->mc_fpformat = npxformat();
3012 	if (!use_xsave || xfpusave_len == 0)
3013 		return;
3014 	max_len = cpu_max_ext_state_size - sizeof(union savefpu);
3015 	len = xfpusave_len;
3016 	if (len > max_len) {
3017 		len = max_len;
3018 		bzero(xfpusave + max_len, len - max_len);
3019 	}
3020 	mcp->mc_flags |= _MC_HASFPXSTATE;
3021 	mcp->mc_xfpustate_len = len;
3022 	bcopy(get_pcb_user_save_td(td) + 1, xfpusave, len);
3023 }
3024 
3025 static int
3026 set_fpcontext(struct thread *td, mcontext_t *mcp, char *xfpustate,
3027     size_t xfpustate_len)
3028 {
3029 	int error;
3030 
3031 	if (mcp->mc_fpformat == _MC_FPFMT_NODEV)
3032 		return (0);
3033 	else if (mcp->mc_fpformat != _MC_FPFMT_387 &&
3034 	    mcp->mc_fpformat != _MC_FPFMT_XMM)
3035 		return (EINVAL);
3036 	else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) {
3037 		/* We don't care what state is left in the FPU or PCB. */
3038 		fpstate_drop(td);
3039 		error = 0;
3040 	} else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU ||
3041 	    mcp->mc_ownedfp == _MC_FPOWNED_PCB) {
3042 		error = npxsetregs(td, (union savefpu *)&mcp->mc_fpstate,
3043 		    xfpustate, xfpustate_len);
3044 	} else
3045 		return (EINVAL);
3046 	return (error);
3047 }
3048 
3049 static void
3050 fpstate_drop(struct thread *td)
3051 {
3052 
3053 	KASSERT(PCB_USER_FPU(td->td_pcb), ("fpstate_drop: kernel-owned fpu"));
3054 	critical_enter();
3055 	if (PCPU_GET(fpcurthread) == td)
3056 		npxdrop();
3057 	/*
3058 	 * XXX force a full drop of the npx.  The above only drops it if we
3059 	 * owned it.  npxgetregs() has the same bug in the !cpu_fxsr case.
3060 	 *
3061 	 * XXX I don't much like npxgetregs()'s semantics of doing a full
3062 	 * drop.  Dropping only to the pcb matches fnsave's behaviour.
3063 	 * We only need to drop to !PCB_INITDONE in sendsig().  But
3064 	 * sendsig() is the only caller of npxgetregs()... perhaps we just
3065 	 * have too many layers.
3066 	 */
3067 	curthread->td_pcb->pcb_flags &= ~(PCB_NPXINITDONE |
3068 	    PCB_NPXUSERINITDONE);
3069 	critical_exit();
3070 }
3071 
3072 int
3073 fill_dbregs(struct thread *td, struct dbreg *dbregs)
3074 {
3075 	struct pcb *pcb;
3076 
3077 	if (td == NULL) {
3078 		dbregs->dr[0] = rdr0();
3079 		dbregs->dr[1] = rdr1();
3080 		dbregs->dr[2] = rdr2();
3081 		dbregs->dr[3] = rdr3();
3082 		dbregs->dr[6] = rdr6();
3083 		dbregs->dr[7] = rdr7();
3084 	} else {
3085 		pcb = td->td_pcb;
3086 		dbregs->dr[0] = pcb->pcb_dr0;
3087 		dbregs->dr[1] = pcb->pcb_dr1;
3088 		dbregs->dr[2] = pcb->pcb_dr2;
3089 		dbregs->dr[3] = pcb->pcb_dr3;
3090 		dbregs->dr[6] = pcb->pcb_dr6;
3091 		dbregs->dr[7] = pcb->pcb_dr7;
3092 	}
3093 	dbregs->dr[4] = 0;
3094 	dbregs->dr[5] = 0;
3095 	return (0);
3096 }
3097 
3098 int
3099 set_dbregs(struct thread *td, struct dbreg *dbregs)
3100 {
3101 	struct pcb *pcb;
3102 	int i;
3103 
3104 	if (td == NULL) {
3105 		load_dr0(dbregs->dr[0]);
3106 		load_dr1(dbregs->dr[1]);
3107 		load_dr2(dbregs->dr[2]);
3108 		load_dr3(dbregs->dr[3]);
3109 		load_dr6(dbregs->dr[6]);
3110 		load_dr7(dbregs->dr[7]);
3111 	} else {
3112 		/*
3113 		 * Don't let an illegal value for dr7 get set.	Specifically,
3114 		 * check for undefined settings.  Setting these bit patterns
3115 		 * result in undefined behaviour and can lead to an unexpected
3116 		 * TRCTRAP.
3117 		 */
3118 		for (i = 0; i < 4; i++) {
3119 			if (DBREG_DR7_ACCESS(dbregs->dr[7], i) == 0x02)
3120 				return (EINVAL);
3121 			if (DBREG_DR7_LEN(dbregs->dr[7], i) == 0x02)
3122 				return (EINVAL);
3123 		}
3124 
3125 		pcb = td->td_pcb;
3126 
3127 		/*
3128 		 * Don't let a process set a breakpoint that is not within the
3129 		 * process's address space.  If a process could do this, it
3130 		 * could halt the system by setting a breakpoint in the kernel
3131 		 * (if ddb was enabled).  Thus, we need to check to make sure
3132 		 * that no breakpoints are being enabled for addresses outside
3133 		 * process's address space.
3134 		 *
3135 		 * XXX - what about when the watched area of the user's
3136 		 * address space is written into from within the kernel
3137 		 * ... wouldn't that still cause a breakpoint to be generated
3138 		 * from within kernel mode?
3139 		 */
3140 
3141 		if (DBREG_DR7_ENABLED(dbregs->dr[7], 0)) {
3142 			/* dr0 is enabled */
3143 			if (dbregs->dr[0] >= VM_MAXUSER_ADDRESS)
3144 				return (EINVAL);
3145 		}
3146 
3147 		if (DBREG_DR7_ENABLED(dbregs->dr[7], 1)) {
3148 			/* dr1 is enabled */
3149 			if (dbregs->dr[1] >= VM_MAXUSER_ADDRESS)
3150 				return (EINVAL);
3151 		}
3152 
3153 		if (DBREG_DR7_ENABLED(dbregs->dr[7], 2)) {
3154 			/* dr2 is enabled */
3155 			if (dbregs->dr[2] >= VM_MAXUSER_ADDRESS)
3156 				return (EINVAL);
3157 		}
3158 
3159 		if (DBREG_DR7_ENABLED(dbregs->dr[7], 3)) {
3160 			/* dr3 is enabled */
3161 			if (dbregs->dr[3] >= VM_MAXUSER_ADDRESS)
3162 				return (EINVAL);
3163 		}
3164 
3165 		pcb->pcb_dr0 = dbregs->dr[0];
3166 		pcb->pcb_dr1 = dbregs->dr[1];
3167 		pcb->pcb_dr2 = dbregs->dr[2];
3168 		pcb->pcb_dr3 = dbregs->dr[3];
3169 		pcb->pcb_dr6 = dbregs->dr[6];
3170 		pcb->pcb_dr7 = dbregs->dr[7];
3171 
3172 		pcb->pcb_flags |= PCB_DBREGS;
3173 	}
3174 
3175 	return (0);
3176 }
3177 
3178 /*
3179  * Return > 0 if a hardware breakpoint has been hit, and the
3180  * breakpoint was in user space.  Return 0, otherwise.
3181  */
3182 int
3183 user_dbreg_trap(register_t dr6)
3184 {
3185         u_int32_t dr7;
3186         u_int32_t bp;       /* breakpoint bits extracted from dr6 */
3187         int nbp;            /* number of breakpoints that triggered */
3188         caddr_t addr[4];    /* breakpoint addresses */
3189         int i;
3190 
3191         bp = dr6 & DBREG_DR6_BMASK;
3192         if (bp == 0) {
3193                 /*
3194                  * None of the breakpoint bits are set meaning this
3195                  * trap was not caused by any of the debug registers
3196                  */
3197                 return 0;
3198         }
3199 
3200         dr7 = rdr7();
3201         if ((dr7 & 0x000000ff) == 0) {
3202                 /*
3203                  * all GE and LE bits in the dr7 register are zero,
3204                  * thus the trap couldn't have been caused by the
3205                  * hardware debug registers
3206                  */
3207                 return 0;
3208         }
3209 
3210         nbp = 0;
3211 
3212         /*
3213          * at least one of the breakpoints were hit, check to see
3214          * which ones and if any of them are user space addresses
3215          */
3216 
3217         if (bp & 0x01) {
3218                 addr[nbp++] = (caddr_t)rdr0();
3219         }
3220         if (bp & 0x02) {
3221                 addr[nbp++] = (caddr_t)rdr1();
3222         }
3223         if (bp & 0x04) {
3224                 addr[nbp++] = (caddr_t)rdr2();
3225         }
3226         if (bp & 0x08) {
3227                 addr[nbp++] = (caddr_t)rdr3();
3228         }
3229 
3230         for (i = 0; i < nbp; i++) {
3231                 if (addr[i] < (caddr_t)VM_MAXUSER_ADDRESS) {
3232                         /*
3233                          * addr[i] is in user space
3234                          */
3235                         return nbp;
3236                 }
3237         }
3238 
3239         /*
3240          * None of the breakpoints are in user space.
3241          */
3242         return 0;
3243 }
3244 
3245 #ifdef KDB
3246 
3247 /*
3248  * Provide inb() and outb() as functions.  They are normally only available as
3249  * inline functions, thus cannot be called from the debugger.
3250  */
3251 
3252 /* silence compiler warnings */
3253 u_char inb_(u_short);
3254 void outb_(u_short, u_char);
3255 
3256 u_char
3257 inb_(u_short port)
3258 {
3259 	return inb(port);
3260 }
3261 
3262 void
3263 outb_(u_short port, u_char data)
3264 {
3265 	outb(port, data);
3266 }
3267 
3268 #endif /* KDB */
3269