trap.c revision 281158
1/*-
2 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
3 * Copyright (C) 1995, 1996 TooLs GmbH.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by TooLs GmbH.
17 * 4. The name of TooLs GmbH may not be used to endorse or promote products
18 *    derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * $NetBSD: trap.c,v 1.58 2002/03/04 04:07:35 dbj Exp $
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD: head/sys/powerpc/powerpc/trap.c 281158 2015-04-06 16:29:45Z jhibbits $");
36
37#include <sys/param.h>
38#include <sys/kdb.h>
39#include <sys/proc.h>
40#include <sys/ktr.h>
41#include <sys/lock.h>
42#include <sys/mutex.h>
43#include <sys/pioctl.h>
44#include <sys/ptrace.h>
45#include <sys/reboot.h>
46#include <sys/syscall.h>
47#include <sys/sysent.h>
48#include <sys/systm.h>
49#include <sys/kernel.h>
50#include <sys/uio.h>
51#include <sys/signalvar.h>
52#include <sys/vmmeter.h>
53
54#include <security/audit/audit.h>
55
56#include <vm/vm.h>
57#include <vm/pmap.h>
58#include <vm/vm_extern.h>
59#include <vm/vm_param.h>
60#include <vm/vm_kern.h>
61#include <vm/vm_map.h>
62#include <vm/vm_page.h>
63
64#include <machine/_inttypes.h>
65#include <machine/altivec.h>
66#include <machine/cpu.h>
67#include <machine/db_machdep.h>
68#include <machine/fpu.h>
69#include <machine/frame.h>
70#include <machine/pcb.h>
71#include <machine/pmap.h>
72#include <machine/psl.h>
73#include <machine/trap.h>
74#include <machine/spr.h>
75#include <machine/sr.h>
76
77#define	FAULTBUF_LR	0
78#define	FAULTBUF_R1	1
79#define	FAULTBUF_R2	2
80#define	FAULTBUF_CR	3
81#define	FAULTBUF_R13	4
82
83static void	trap_fatal(struct trapframe *frame);
84static void	printtrap(u_int vector, struct trapframe *frame, int isfatal,
85		    int user);
86static int	trap_pfault(struct trapframe *frame, int user);
87static int	fix_unaligned(struct thread *td, struct trapframe *frame);
88static int	handle_onfault(struct trapframe *frame);
89static void	syscall(struct trapframe *frame);
90
91#ifdef __powerpc64__
92       void	handle_kernel_slb_spill(int, register_t, register_t);
93static int	handle_user_slb_spill(pmap_t pm, vm_offset_t addr);
94extern int	n_slbs;
95#endif
96
97struct powerpc_exception {
98	u_int	vector;
99	char	*name;
100};
101
102#ifdef KDTRACE_HOOKS
103#include <sys/dtrace_bsd.h>
104
105int (*dtrace_invop_jump_addr)(struct trapframe *);
106#endif
107
108static struct powerpc_exception powerpc_exceptions[] = {
109	{ EXC_CRIT,	"critical input" },
110	{ EXC_RST,	"system reset" },
111	{ EXC_MCHK,	"machine check" },
112	{ EXC_DSI,	"data storage interrupt" },
113	{ EXC_DSE,	"data segment exception" },
114	{ EXC_ISI,	"instruction storage interrupt" },
115	{ EXC_ISE,	"instruction segment exception" },
116	{ EXC_EXI,	"external interrupt" },
117	{ EXC_ALI,	"alignment" },
118	{ EXC_PGM,	"program" },
119	{ EXC_FPU,	"floating-point unavailable" },
120	{ EXC_APU,	"auxiliary proc unavailable" },
121	{ EXC_DECR,	"decrementer" },
122	{ EXC_FIT,	"fixed-interval timer" },
123	{ EXC_WDOG,	"watchdog timer" },
124	{ EXC_SC,	"system call" },
125	{ EXC_TRC,	"trace" },
126	{ EXC_FPA,	"floating-point assist" },
127	{ EXC_DEBUG,	"debug" },
128	{ EXC_PERF,	"performance monitoring" },
129	{ EXC_VEC,	"altivec unavailable" },
130	{ EXC_VSX,	"vsx unavailable" },
131	{ EXC_ITMISS,	"instruction tlb miss" },
132	{ EXC_DLMISS,	"data load tlb miss" },
133	{ EXC_DSMISS,	"data store tlb miss" },
134	{ EXC_BPT,	"instruction breakpoint" },
135	{ EXC_SMI,	"system management" },
136	{ EXC_VECAST_G4,	"altivec assist" },
137	{ EXC_THRM,	"thermal management" },
138	{ EXC_RUNMODETRC,	"run mode/trace" },
139	{ EXC_LAST,	NULL }
140};
141
142static const char *
143trapname(u_int vector)
144{
145	struct	powerpc_exception *pe;
146
147	for (pe = powerpc_exceptions; pe->vector != EXC_LAST; pe++) {
148		if (pe->vector == vector)
149			return (pe->name);
150	}
151
152	return ("unknown");
153}
154
155void
156trap(struct trapframe *frame)
157{
158	struct thread	*td;
159	struct proc	*p;
160#ifdef KDTRACE_HOOKS
161	uint32_t inst;
162#endif
163	int		sig, type, user;
164	u_int		ucode;
165	ksiginfo_t	ksi;
166
167	PCPU_INC(cnt.v_trap);
168
169	td = curthread;
170	p = td->td_proc;
171
172	type = ucode = frame->exc;
173	sig = 0;
174	user = frame->srr1 & PSL_PR;
175
176	CTR3(KTR_TRAP, "trap: %s type=%s (%s)", td->td_name,
177	    trapname(type), user ? "user" : "kernel");
178
179#ifdef KDTRACE_HOOKS
180	/*
181	 * A trap can occur while DTrace executes a probe. Before
182	 * executing the probe, DTrace blocks re-scheduling and sets
183	 * a flag in its per-cpu flags to indicate that it doesn't
184	 * want to fault. On returning from the probe, the no-fault
185	 * flag is cleared and finally re-scheduling is enabled.
186	 *
187	 * If the DTrace kernel module has registered a trap handler,
188	 * call it and if it returns non-zero, assume that it has
189	 * handled the trap and modified the trap frame so that this
190	 * function can return normally.
191	 */
192	if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type) != 0)
193		return;
194#endif
195
196	if (user) {
197		td->td_pticks = 0;
198		td->td_frame = frame;
199		if (td->td_ucred != p->p_ucred)
200			cred_update_thread(td);
201
202		/* User Mode Traps */
203		switch (type) {
204		case EXC_RUNMODETRC:
205		case EXC_TRC:
206			frame->srr1 &= ~PSL_SE;
207			sig = SIGTRAP;
208			ucode = TRAP_TRACE;
209			break;
210
211#ifdef __powerpc64__
212		case EXC_ISE:
213		case EXC_DSE:
214			if (handle_user_slb_spill(&p->p_vmspace->vm_pmap,
215			    (type == EXC_ISE) ? frame->srr0 : frame->dar) != 0){
216				sig = SIGSEGV;
217				ucode = SEGV_MAPERR;
218			}
219			break;
220#endif
221		case EXC_DSI:
222		case EXC_ISI:
223			sig = trap_pfault(frame, 1);
224			if (sig == SIGSEGV)
225				ucode = SEGV_MAPERR;
226			break;
227
228		case EXC_SC:
229			syscall(frame);
230			break;
231
232		case EXC_FPU:
233			KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU,
234			    ("FPU already enabled for thread"));
235			enable_fpu(td);
236			break;
237
238		case EXC_VEC:
239			KASSERT((td->td_pcb->pcb_flags & PCB_VEC) != PCB_VEC,
240			    ("Altivec already enabled for thread"));
241			enable_vec(td);
242			break;
243
244		case EXC_VSX:
245			KASSERT((td->td_pcb->pcb_flags & PCB_VSX) != PCB_VSX,
246			    ("VSX already enabled for thread"));
247			if (!(td->td_pcb->pcb_flags & PCB_VEC))
248				enable_vec(td);
249			if (!(td->td_pcb->pcb_flags & PCB_FPU))
250				save_fpu(td);
251			td->td_pcb->pcb_flags |= PCB_VSX;
252			enable_fpu(td);
253			break;
254
255		case EXC_VECAST_G4:
256		case EXC_VECAST_G5:
257			/*
258			 * We get a VPU assist exception for IEEE mode
259			 * vector operations on denormalized floats.
260			 * Emulating this is a giant pain, so for now,
261			 * just switch off IEEE mode and treat them as
262			 * zero.
263			 */
264
265			save_vec(td);
266			td->td_pcb->pcb_vec.vscr |= ALTIVEC_VSCR_NJ;
267			enable_vec(td);
268			break;
269
270		case EXC_ALI:
271			if (fix_unaligned(td, frame) != 0) {
272				sig = SIGBUS;
273				ucode = BUS_ADRALN;
274			}
275			else
276				frame->srr0 += 4;
277			break;
278
279		case EXC_DEBUG:	/* Single stepping */
280			mtspr(SPR_DBSR, mfspr(SPR_DBSR));
281			frame->srr1 &= ~PSL_DE;
282			frame->cpu.booke.dbcr0 &= ~(DBCR0_IDM || DBCR0_IC);
283			sig = SIGTRAP;
284			ucode = TRAP_TRACE;
285			break;
286
287		case EXC_PGM:
288			/* Identify the trap reason */
289#ifdef AIM
290			if (frame->srr1 & EXC_PGM_TRAP) {
291#else
292			if (frame->cpu.booke.esr & ESR_PTR) {
293#endif
294#ifdef KDTRACE_HOOKS
295				inst = fuword32((const void *)frame->srr0);
296				if (inst == 0x0FFFDDDD &&
297				    dtrace_pid_probe_ptr != NULL) {
298					struct reg regs;
299					fill_regs(td, &regs);
300					(*dtrace_pid_probe_ptr)(&regs);
301					break;
302				}
303#endif
304 				sig = SIGTRAP;
305				ucode = TRAP_BRKPT;
306			} else {
307				sig = ppc_instr_emulate(frame, td->td_pcb);
308				if (sig == SIGILL) {
309					if (frame->srr1 & EXC_PGM_PRIV)
310						ucode = ILL_PRVOPC;
311					else if (frame->srr1 & EXC_PGM_ILLEGAL)
312						ucode = ILL_ILLOPC;
313				} else if (sig == SIGFPE)
314					ucode = FPE_FLTINV;	/* Punt for now, invalid operation. */
315			}
316			break;
317
318		case EXC_MCHK:
319			/*
320			 * Note that this may not be recoverable for the user
321			 * process, depending on the type of machine check,
322			 * but it at least prevents the kernel from dying.
323			 */
324			sig = SIGBUS;
325			ucode = BUS_OBJERR;
326			break;
327
328		default:
329			trap_fatal(frame);
330		}
331	} else {
332		/* Kernel Mode Traps */
333
334		KASSERT(cold || td->td_ucred != NULL,
335		    ("kernel trap doesn't have ucred"));
336		switch (type) {
337#ifdef KDTRACE_HOOKS
338		case EXC_PGM:
339			if (frame->srr1 & EXC_PGM_TRAP) {
340				if (*(uint32_t *)frame->srr0 == EXC_DTRACE) {
341					if (dtrace_invop_jump_addr != NULL) {
342						dtrace_invop_jump_addr(frame);
343						return;
344					}
345				}
346			}
347			break;
348#endif
349#ifdef __powerpc64__
350		case EXC_DSE:
351			if ((frame->dar & SEGMENT_MASK) == USER_ADDR) {
352				__asm __volatile ("slbmte %0, %1" ::
353					"r"(td->td_pcb->pcb_cpu.aim.usr_vsid),
354					"r"(USER_SLB_SLBE));
355				return;
356			}
357			break;
358#endif
359		case EXC_DSI:
360			if (trap_pfault(frame, 0) == 0)
361 				return;
362			break;
363		case EXC_MCHK:
364			if (handle_onfault(frame))
365 				return;
366			break;
367		default:
368			break;
369		}
370		trap_fatal(frame);
371	}
372
373	if (sig != 0) {
374		if (p->p_sysent->sv_transtrap != NULL)
375			sig = (p->p_sysent->sv_transtrap)(sig, type);
376		ksiginfo_init_trap(&ksi);
377		ksi.ksi_signo = sig;
378		ksi.ksi_code = (int) ucode; /* XXX, not POSIX */
379		/* ksi.ksi_addr = ? */
380		ksi.ksi_trapno = type;
381		trapsignal(td, &ksi);
382	}
383
384	userret(td, frame);
385}
386
387static void
388trap_fatal(struct trapframe *frame)
389{
390
391	printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR));
392#ifdef KDB
393	if ((debugger_on_panic || kdb_active) &&
394	    kdb_trap(frame->exc, 0, frame))
395		return;
396#endif
397	panic("%s trap", trapname(frame->exc));
398}
399
400static void
401printtrap(u_int vector, struct trapframe *frame, int isfatal, int user)
402{
403
404	printf("\n");
405	printf("%s %s trap:\n", isfatal ? "fatal" : "handled",
406	    user ? "user" : "kernel");
407	printf("\n");
408	printf("   exception       = 0x%x (%s)\n", vector, trapname(vector));
409	switch (vector) {
410	case EXC_DTMISS:
411	case EXC_DSE:
412	case EXC_DSI:
413		printf("   virtual address = 0x%" PRIxPTR "\n", frame->dar);
414		printf("   dsisr           = 0x%" PRIxPTR "\n",
415		    frame->cpu.aim.dsisr);
416		break;
417	case EXC_ITMISS:
418	case EXC_ISE:
419	case EXC_ISI:
420		printf("   virtual address = 0x%" PRIxPTR "\n", frame->srr0);
421		break;
422	}
423	printf("   srr0            = 0x%" PRIxPTR "\n", frame->srr0);
424	printf("   srr1            = 0x%" PRIxPTR "\n", frame->srr1);
425	printf("   lr              = 0x%" PRIxPTR "\n", frame->lr);
426	printf("   curthread       = %p\n", curthread);
427	if (curthread != NULL)
428		printf("          pid = %d, comm = %s\n",
429		    curthread->td_proc->p_pid, curthread->td_name);
430	printf("\n");
431}
432
433/*
434 * Handles a fatal fault when we have onfault state to recover.  Returns
435 * non-zero if there was onfault recovery state available.
436 */
437static int
438handle_onfault(struct trapframe *frame)
439{
440	struct		thread *td;
441	faultbuf	*fb;
442
443	td = curthread;
444	fb = td->td_pcb->pcb_onfault;
445	if (fb != NULL) {
446		frame->srr0 = (*fb)[FAULTBUF_LR];
447		frame->fixreg[1] = (*fb)[FAULTBUF_R1];
448		frame->fixreg[2] = (*fb)[FAULTBUF_R2];
449		frame->fixreg[3] = 1;
450		frame->cr = (*fb)[FAULTBUF_CR];
451		bcopy(&(*fb)[FAULTBUF_R13], &frame->fixreg[13],
452		    19 * sizeof(register_t));
453		return (1);
454	}
455	return (0);
456}
457
458int
459cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
460{
461	struct proc *p;
462	struct trapframe *frame;
463	caddr_t	params;
464	size_t argsz;
465	int error, n, i;
466
467	p = td->td_proc;
468	frame = td->td_frame;
469
470	sa->code = frame->fixreg[0];
471	params = (caddr_t)(frame->fixreg + FIRSTARG);
472	n = NARGREG;
473
474	if (sa->code == SYS_syscall) {
475		/*
476		 * code is first argument,
477		 * followed by actual args.
478		 */
479		sa->code = *(register_t *) params;
480		params += sizeof(register_t);
481		n -= 1;
482	} else if (sa->code == SYS___syscall) {
483		/*
484		 * Like syscall, but code is a quad,
485		 * so as to maintain quad alignment
486		 * for the rest of the args.
487		 */
488		if (SV_PROC_FLAG(p, SV_ILP32)) {
489			params += sizeof(register_t);
490			sa->code = *(register_t *) params;
491			params += sizeof(register_t);
492			n -= 2;
493		} else {
494			sa->code = *(register_t *) params;
495			params += sizeof(register_t);
496			n -= 1;
497		}
498	}
499
500 	if (p->p_sysent->sv_mask)
501		sa->code &= p->p_sysent->sv_mask;
502	if (sa->code >= p->p_sysent->sv_size)
503		sa->callp = &p->p_sysent->sv_table[0];
504	else
505		sa->callp = &p->p_sysent->sv_table[sa->code];
506
507	sa->narg = sa->callp->sy_narg;
508
509	if (SV_PROC_FLAG(p, SV_ILP32)) {
510		argsz = sizeof(uint32_t);
511
512		for (i = 0; i < n; i++)
513			sa->args[i] = ((u_register_t *)(params))[i] &
514			    0xffffffff;
515	} else {
516		argsz = sizeof(uint64_t);
517
518		for (i = 0; i < n; i++)
519			sa->args[i] = ((u_register_t *)(params))[i];
520	}
521
522	if (sa->narg > n)
523		error = copyin(MOREARGS(frame->fixreg[1]), sa->args + n,
524			       (sa->narg - n) * argsz);
525	else
526		error = 0;
527
528#ifdef __powerpc64__
529	if (SV_PROC_FLAG(p, SV_ILP32) && sa->narg > n) {
530		/* Expand the size of arguments copied from the stack */
531
532		for (i = sa->narg; i >= n; i--)
533			sa->args[i] = ((uint32_t *)(&sa->args[n]))[i-n];
534	}
535#endif
536
537	if (error == 0) {
538		td->td_retval[0] = 0;
539		td->td_retval[1] = frame->fixreg[FIRSTARG + 1];
540	}
541	return (error);
542}
543
544#include "../../kern/subr_syscall.c"
545
546void
547syscall(struct trapframe *frame)
548{
549	struct thread *td;
550	struct syscall_args sa;
551	int error;
552
553	td = curthread;
554	td->td_frame = frame;
555
556#ifdef __powerpc64__
557	/*
558	 * Speculatively restore last user SLB segment, which we know is
559	 * invalid already, since we are likely to do copyin()/copyout().
560	 */
561	__asm __volatile ("slbmte %0, %1; isync" ::
562            "r"(td->td_pcb->pcb_cpu.aim.usr_vsid), "r"(USER_SLB_SLBE));
563#endif
564
565	error = syscallenter(td, &sa);
566	syscallret(td, error, &sa);
567}
568
569#ifdef __powerpc64__
570/* Handle kernel SLB faults -- runs in real mode, all seat belts off */
571void
572handle_kernel_slb_spill(int type, register_t dar, register_t srr0)
573{
574	struct slb *slbcache;
575	uint64_t slbe, slbv;
576	uint64_t esid, addr;
577	int i;
578
579	addr = (type == EXC_ISE) ? srr0 : dar;
580	slbcache = PCPU_GET(slb);
581	esid = (uintptr_t)addr >> ADDR_SR_SHFT;
582	slbe = (esid << SLBE_ESID_SHIFT) | SLBE_VALID;
583
584	/* See if the hardware flushed this somehow (can happen in LPARs) */
585	for (i = 0; i < n_slbs; i++)
586		if (slbcache[i].slbe == (slbe | (uint64_t)i))
587			return;
588
589	/* Not in the map, needs to actually be added */
590	slbv = kernel_va_to_slbv(addr);
591	if (slbcache[USER_SLB_SLOT].slbe == 0) {
592		for (i = 0; i < n_slbs; i++) {
593			if (i == USER_SLB_SLOT)
594				continue;
595			if (!(slbcache[i].slbe & SLBE_VALID))
596				goto fillkernslb;
597		}
598
599		if (i == n_slbs)
600			slbcache[USER_SLB_SLOT].slbe = 1;
601	}
602
603	/* Sacrifice a random SLB entry that is not the user entry */
604	i = mftb() % n_slbs;
605	if (i == USER_SLB_SLOT)
606		i = (i+1) % n_slbs;
607
608fillkernslb:
609	/* Write new entry */
610	slbcache[i].slbv = slbv;
611	slbcache[i].slbe = slbe | (uint64_t)i;
612
613	/* Trap handler will restore from cache on exit */
614}
615
616static int
617handle_user_slb_spill(pmap_t pm, vm_offset_t addr)
618{
619	struct slb *user_entry;
620	uint64_t esid;
621	int i;
622
623	esid = (uintptr_t)addr >> ADDR_SR_SHFT;
624
625	PMAP_LOCK(pm);
626	user_entry = user_va_to_slb_entry(pm, addr);
627
628	if (user_entry == NULL) {
629		/* allocate_vsid auto-spills it */
630		(void)allocate_user_vsid(pm, esid, 0);
631	} else {
632		/*
633		 * Check that another CPU has not already mapped this.
634		 * XXX: Per-thread SLB caches would be better.
635		 */
636		for (i = 0; i < pm->pm_slb_len; i++)
637			if (pm->pm_slb[i] == user_entry)
638				break;
639
640		if (i == pm->pm_slb_len)
641			slb_insert_user(pm, user_entry);
642	}
643	PMAP_UNLOCK(pm);
644
645	return (0);
646}
647#endif
648
649static int
650trap_pfault(struct trapframe *frame, int user)
651{
652	vm_offset_t	eva, va;
653	struct		thread *td;
654	struct		proc *p;
655	vm_map_t	map;
656	vm_prot_t	ftype;
657	int		rv;
658#ifdef AIM
659	register_t	user_sr;
660#endif
661
662	td = curthread;
663	p = td->td_proc;
664	if (frame->exc == EXC_ISI) {
665		eva = frame->srr0;
666		ftype = VM_PROT_EXECUTE;
667		if (frame->srr1 & SRR1_ISI_PFAULT)
668			ftype |= VM_PROT_READ;
669	} else {
670		eva = frame->dar;
671#ifdef BOOKE
672		if (frame->cpu.booke.esr & ESR_ST)
673#else
674		if (frame->cpu.aim.dsisr & DSISR_STORE)
675#endif
676			ftype = VM_PROT_WRITE;
677		else
678			ftype = VM_PROT_READ;
679	}
680
681	if (user) {
682		KASSERT(p->p_vmspace != NULL, ("trap_pfault: vmspace  NULL"));
683		map = &p->p_vmspace->vm_map;
684	} else {
685#ifdef BOOKE
686		if (eva < VM_MAXUSER_ADDRESS) {
687#else
688		if ((eva >> ADDR_SR_SHFT) == (USER_ADDR >> ADDR_SR_SHFT)) {
689#endif
690			if (p->p_vmspace == NULL)
691				return (SIGSEGV);
692
693			map = &p->p_vmspace->vm_map;
694
695#ifdef AIM
696			user_sr = td->td_pcb->pcb_cpu.aim.usr_segm;
697			eva &= ADDR_PIDX | ADDR_POFF;
698			eva |= user_sr << ADDR_SR_SHFT;
699#endif
700		} else {
701			map = kernel_map;
702		}
703	}
704	va = trunc_page(eva);
705
706	if (map != kernel_map) {
707		/*
708		 * Keep swapout from messing with us during this
709		 *	critical time.
710		 */
711		PROC_LOCK(p);
712		++p->p_lock;
713		PROC_UNLOCK(p);
714
715		/* Fault in the user page: */
716		rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
717
718		PROC_LOCK(p);
719		--p->p_lock;
720		PROC_UNLOCK(p);
721		/*
722		 * XXXDTRACE: add dtrace_doubletrap_func here?
723		 */
724	} else {
725		/*
726		 * Don't have to worry about process locking or stacks in the
727		 * kernel.
728		 */
729		rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
730	}
731
732	if (rv == KERN_SUCCESS)
733		return (0);
734
735	if (!user && handle_onfault(frame))
736		return (0);
737
738	return (SIGSEGV);
739}
740
741/*
742 * For now, this only deals with the particular unaligned access case
743 * that gcc tends to generate.  Eventually it should handle all of the
744 * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
745 */
746
747static int
748fix_unaligned(struct thread *td, struct trapframe *frame)
749{
750	struct thread	*fputhread;
751	int		indicator, reg;
752	double		*fpr;
753
754	indicator = EXC_ALI_OPCODE_INDICATOR(frame->cpu.aim.dsisr);
755
756	switch (indicator) {
757	case EXC_ALI_LFD:
758	case EXC_ALI_STFD:
759		reg = EXC_ALI_RST(frame->cpu.aim.dsisr);
760		fpr = &td->td_pcb->pcb_fpu.fpr[reg].fpr;
761		fputhread = PCPU_GET(fputhread);
762
763		/* Juggle the FPU to ensure that we've initialized
764		 * the FPRs, and that their current state is in
765		 * the PCB.
766		 */
767		if (fputhread != td) {
768			if (fputhread)
769				save_fpu(fputhread);
770			enable_fpu(td);
771		}
772		save_fpu(td);
773
774		if (indicator == EXC_ALI_LFD) {
775			if (copyin((void *)frame->dar, fpr,
776			    sizeof(double)) != 0)
777				return (-1);
778			enable_fpu(td);
779		} else {
780			if (copyout(fpr, (void *)frame->dar,
781			    sizeof(double)) != 0)
782				return (-1);
783		}
784		return (0);
785		break;
786	}
787
788	return (-1);
789}
790
791#ifdef KDB
792int db_trap_glue(struct trapframe *);		/* Called from trap_subr.S */
793
794int
795db_trap_glue(struct trapframe *frame)
796{
797	if (!(frame->srr1 & PSL_PR)
798	    && (frame->exc == EXC_TRC || frame->exc == EXC_RUNMODETRC
799		|| (frame->exc == EXC_PGM
800		    && (frame->srr1 & 0x20000))
801		|| frame->exc == EXC_BPT
802		|| frame->exc == EXC_DSI)) {
803		int type = frame->exc;
804
805		/* Ignore DTrace traps. */
806		if (*(uint32_t *)frame->srr0 == EXC_DTRACE)
807			return (0);
808		if (type == EXC_PGM && (frame->srr1 & 0x20000)) {
809			type = T_BREAKPOINT;
810		}
811		return (kdb_trap(type, 0, frame));
812	}
813
814	return (0);
815}
816#endif
817