trap.c revision 144971 
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/aim/trap.c 144971 2005-04-12 23:18:54Z jhb $");
36
37#include "opt_ktrace.h"
38
39#include <sys/param.h>
40#include <sys/kdb.h>
41#include <sys/proc.h>
42#include <sys/ktr.h>
43#include <sys/lock.h>
44#include <sys/mutex.h>
45#include <sys/pioctl.h>
46#include <sys/reboot.h>
47#include <sys/syscall.h>
48#include <sys/sysent.h>
49#include <sys/systm.h>
50#include <sys/uio.h>
51#include <sys/signalvar.h>
52#ifdef KTRACE
53#include <sys/ktrace.h>
54#endif
55#include <sys/vmmeter.h>
56
57#include <vm/vm.h>
58#include <vm/pmap.h>
59#include <vm/vm_extern.h>
60#include <vm/vm_param.h>
61#include <vm/vm_kern.h>
62#include <vm/vm_map.h>
63#include <vm/vm_page.h>
64
65#include <machine/cpu.h>
66#include <machine/db_machdep.h>
67#include <machine/fpu.h>
68#include <machine/frame.h>
69#include <machine/pcb.h>
70#include <machine/pmap.h>
71#include <machine/psl.h>
72#include <machine/trap.h>
73#include <machine/spr.h>
74#include <machine/sr.h>
75
76void		trap(struct trapframe *);
77
78static void	trap_fatal(struct trapframe *frame);
79static void	printtrap(u_int vector, struct trapframe *frame, int isfatal,
80		    int user);
81static int	trap_pfault(struct trapframe *frame, int user);
82static int	fix_unaligned(struct thread *td, struct trapframe *frame);
83static int	handle_onfault(struct trapframe *frame);
84static void	syscall(struct trapframe *frame);
85
86static __inline void	setusr(u_int);
87
88int	setfault(faultbuf);		/* defined in locore.S */
89
90/* Why are these not defined in a header? */
91int	badaddr(void *, size_t);
92int	badaddr_read(void *, size_t, int *);
93
94extern char	*syscallnames[];
95
96extern int debugger_on_panic; /* XXX */
97
98struct powerpc_exception {
99	u_int	vector;
100	char	*name;
101};
102
103static struct powerpc_exception powerpc_exceptions[] = {
104	{ 0x0100, "system reset" },
105	{ 0x0200, "machine check" },
106	{ 0x0300, "data storage interrupt" },
107	{ 0x0400, "instruction storage interrupt" },
108	{ 0x0500, "external interrupt" },
109	{ 0x0600, "alignment" },
110	{ 0x0700, "program" },
111	{ 0x0800, "floating-point unavailable" },
112	{ 0x0900, "decrementer" },
113	{ 0x0c00, "system call" },
114	{ 0x0d00, "trace" },
115	{ 0x0e00, "floating-point assist" },
116	{ 0x0f00, "performance monitoring" },
117	{ 0x0f20, "altivec unavailable" },
118	{ 0x1000, "instruction tlb miss" },
119	{ 0x1100, "data load tlb miss" },
120	{ 0x1200, "data store tlb miss" },
121	{ 0x1300, "instruction breakpoint" },
122	{ 0x1400, "system management" },
123	{ 0x1600, "altivec assist" },
124	{ 0x1700, "thermal management" },
125	{ 0x2000, "run mode/trace" },
126	{ 0x3000, NULL }
127};
128
129static const char *
130trapname(u_int vector)
131{
132	struct	powerpc_exception *pe;
133
134	for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) {
135		if (pe->vector == vector)
136			return (pe->name);
137	}
138
139	return ("unknown");
140}
141
142void
143trap(struct trapframe *frame)
144{
145	struct thread	*td;
146	struct proc	*p;
147	int		sig, type, user;
148	u_int		sticks, ucode;
149
150	PCPU_LAZY_INC(cnt.v_trap);
151
152	td = PCPU_GET(curthread);
153	p = td->td_proc;
154
155	type = ucode = frame->exc;
156	sig = 0;
157	user = frame->srr1 & PSL_PR;
158	sticks = 0;
159
160	CTR3(KTR_TRAP, "trap: %s type=%s (%s)", p->p_comm,
161	    trapname(type), user ? "user" : "kernel");
162
163	if (user) {
164		sticks = td->td_sticks;
165		td->td_frame = frame;
166		if (td->td_ucred != p->p_ucred)
167			cred_update_thread(td);
168
169		/* User Mode Traps */
170		switch (type) {
171		case EXC_RUNMODETRC:
172		case EXC_TRC:
173			frame->srr1 &= ~PSL_SE;
174			sig = SIGTRAP;
175			break;
176
177		case EXC_DSI:
178		case EXC_ISI:
179			sig = trap_pfault(frame, 1);
180			break;
181
182		case EXC_SC:
183			syscall(frame);
184			break;
185
186		case EXC_FPU:
187			KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU,
188			    ("FPU already enabled for thread"));
189			enable_fpu(td);
190			break;
191
192#ifdef	ALTIVEC
193		case EXC_VEC:
194			if ((vecthread = PCPU_GET(vecthread)) != NULL) {
195				KASSERT(vecthread != td,
196				    ("altivec already enabled"));
197				save_vec(vecthread);
198			}
199			PCPU_SET(vecthread, td);
200			td->td_pcb->pcb_veccpu = PCPU_GET(cpuid);
201			enable_vec(td);
202			frame->srr1 |= PSL_VEC;
203			break;
204#endif /* ALTIVEC */
205
206		case EXC_ALI:
207			if (fix_unaligned(td, frame) != 0)
208				sig = SIGBUS;
209			else
210				frame->srr0 += 4;
211			break;
212
213		case EXC_PGM:
214			/* XXX temporarily */
215			/* XXX: Magic Number? */
216			if (frame->srr1 & 0x0002000)
217				sig = SIGTRAP;
218 			else
219				sig = SIGILL;
220			break;
221
222		default:
223			trap_fatal(frame);
224		}
225	} else {
226		/* Kernel Mode Traps */
227
228		KASSERT(cold || td->td_ucred != NULL,
229		    ("kernel trap doesn't have ucred"));
230		switch (type) {
231		case EXC_DSI:
232			if (trap_pfault(frame, 0) == 0)
233 				return;
234			break;
235		case EXC_MCHK:
236			if (handle_onfault(frame))
237 				return;
238			break;
239		default:
240			break;
241		}
242		trap_fatal(frame);
243	}
244
245#ifdef	ALTIVEC
246	if (td != PCPU_GET(vecthread) ||
247	    td->td_pcb->pcb_veccpu != PCPU_GET(cpuid))
248		frame->srr1 &= ~PSL_VEC;
249#endif /* ALTIVEC */
250
251	if (sig != 0) {
252		if (p->p_sysent->sv_transtrap != NULL)
253			sig = (p->p_sysent->sv_transtrap)(sig, type);
254		trapsignal(td, sig, ucode);
255	}
256
257	userret(td, frame, sticks);
258	mtx_assert(&Giant, MA_NOTOWNED);
259}
260
261static void
262trap_fatal(struct trapframe *frame)
263{
264
265	printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR));
266#ifdef KDB
267	if ((debugger_on_panic || kdb_active) &&
268	    kdb_trap(frame->exc, 0, frame))
269		return;
270#endif
271	panic("%s trap", trapname(frame->exc));
272}
273
274static void
275printtrap(u_int vector, struct trapframe *frame, int isfatal, int user)
276{
277
278	printf("\n");
279	printf("%s %s trap:\n", isfatal ? "fatal" : "handled",
280	    user ? "user" : "kernel");
281	printf("\n");
282	printf("   exception       = 0x%x (%s)\n", vector >> 8,
283	    trapname(vector));
284	switch (vector) {
285	case EXC_DSI:
286		printf("   virtual address = 0x%x\n", frame->dar);
287		break;
288	case EXC_ISI:
289		printf("   virtual address = 0x%x\n", frame->srr0);
290		break;
291	}
292	printf("   srr0            = 0x%x\n", frame->srr0);
293	printf("   srr1            = 0x%x\n", frame->srr1);
294	printf("   curthread       = %p\n", curthread);
295	if (curthread != NULL)
296		printf("          pid = %d, comm = %s\n",
297		    curthread->td_proc->p_pid, curthread->td_proc->p_comm);
298	printf("\n");
299}
300
301/*
302 * Handles a fatal fault when we have onfault state to recover.  Returns
303 * non-zero if there was onfault recovery state available.
304 */
305static int
306handle_onfault(struct trapframe *frame)
307{
308	struct		thread *td;
309	faultbuf	*fb;
310
311	td = curthread;
312	fb = td->td_pcb->pcb_onfault;
313	if (fb != NULL) {
314		frame->srr0 = (*fb)[0];
315		frame->fixreg[1] = (*fb)[1];
316		frame->fixreg[2] = (*fb)[2];
317		frame->fixreg[3] = 1;
318		frame->cr = (*fb)[3];
319		bcopy(&(*fb)[4], &frame->fixreg[13],
320		    19 * sizeof(register_t));
321		return (1);
322	}
323	return (0);
324}
325
326void
327syscall(struct trapframe *frame)
328{
329	caddr_t		params;
330	struct		sysent *callp;
331	struct		thread *td;
332	struct		proc *p;
333	int		error, n;
334	size_t		narg;
335	register_t	args[10];
336	u_int		code;
337
338	td = PCPU_GET(curthread);
339	p = td->td_proc;
340
341	PCPU_LAZY_INC(cnt.v_syscall);
342
343	if (p->p_flag & P_SA)
344		thread_user_enter(td);
345
346	code = frame->fixreg[0];
347	params = (caddr_t)(frame->fixreg + FIRSTARG);
348	n = NARGREG;
349
350	if (p->p_sysent->sv_prepsyscall) {
351		/*
352		 * The prep code is MP aware.
353		 */
354		(*p->p_sysent->sv_prepsyscall)(frame, args, &code, &params);
355	} else if (code == SYS_syscall) {
356		/*
357		 * code is first argument,
358		 * followed by actual args.
359		 */
360		code = *(u_int *) params;
361		params += sizeof(register_t);
362		n -= 1;
363	} else if (code == SYS___syscall) {
364		/*
365		 * Like syscall, but code is a quad,
366		 * so as to maintain quad alignment
367		 * for the rest of the args.
368		 */
369		params += sizeof(register_t);
370		code = *(u_int *) params;
371		params += sizeof(register_t);
372		n -= 2;
373	}
374
375 	if (p->p_sysent->sv_mask)
376 		code &= p->p_sysent->sv_mask;
377
378 	if (code >= p->p_sysent->sv_size)
379 		callp = &p->p_sysent->sv_table[0];
380  	else
381 		callp = &p->p_sysent->sv_table[code];
382
383	narg = callp->sy_narg & SYF_ARGMASK;
384
385	if (narg > n) {
386		bcopy(params, args, n * sizeof(register_t));
387		error = copyin(MOREARGS(frame->fixreg[1]), args + n,
388			       (narg - n) * sizeof(register_t));
389		params = (caddr_t)args;
390	} else
391		error = 0;
392
393	CTR5(KTR_SYSC, "syscall: p=%s %s(%x %x %x)", p->p_comm,
394	     syscallnames[code],
395	     frame->fixreg[FIRSTARG],
396	     frame->fixreg[FIRSTARG+1],
397	     frame->fixreg[FIRSTARG+2]);
398
399#ifdef	KTRACE
400	if (KTRPOINT(td, KTR_SYSCALL))
401		ktrsyscall(code, narg, (register_t *)params);
402#endif
403	/*
404	 * Try to run the syscall without Giant if the syscall is MP safe.
405	 */
406	if ((callp->sy_narg & SYF_MPSAFE) == 0)
407		mtx_lock(&Giant);
408
409	if (error == 0) {
410		td->td_retval[0] = 0;
411		td->td_retval[1] = frame->fixreg[FIRSTARG + 1];
412
413		STOPEVENT(p, S_SCE, narg);
414
415		error = (*callp->sy_call)(td, params);
416
417		CTR3(KTR_SYSC, "syscall: p=%s %s ret=%x", p->p_comm,
418		     syscallnames[code], td->td_retval[0]);
419	}
420	switch (error) {
421	case 0:
422		if ((frame->fixreg[0] == SYS___syscall) &&
423		    (code != SYS_lseek)) {
424			/*
425			 * 64-bit return, 32-bit syscall. Fixup byte order
426			 */
427			frame->fixreg[FIRSTARG] = 0;
428			frame->fixreg[FIRSTARG + 1] = td->td_retval[0];
429		} else {
430			frame->fixreg[FIRSTARG] = td->td_retval[0];
431			frame->fixreg[FIRSTARG + 1] = td->td_retval[1];
432		}
433		/* XXX: Magic number */
434		frame->cr &= ~0x10000000;
435		break;
436	case ERESTART:
437		/*
438		 * Set user's pc back to redo the system call.
439		 */
440		frame->srr0 -= 4;
441		break;
442	case EJUSTRETURN:
443		/* nothing to do */
444		break;
445	default:
446		if (p->p_sysent->sv_errsize) {
447			if (error >= p->p_sysent->sv_errsize)
448				error = -1;	/* XXX */
449			else
450				error = p->p_sysent->sv_errtbl[error];
451		}
452		frame->fixreg[FIRSTARG] = error;
453		/* XXX: Magic number: Carry Flag Equivalent? */
454		frame->cr |= 0x10000000;
455		break;
456	}
457
458
459	if ((callp->sy_narg & SYF_MPSAFE) == 0)
460		mtx_unlock(&Giant);
461
462#ifdef	KTRACE
463	if (KTRPOINT(td, KTR_SYSRET))
464		ktrsysret(code, error, td->td_retval[0]);
465#endif
466
467	/*
468	 * Does the comment in the i386 code about errno apply here?
469	 */
470	STOPEVENT(p, S_SCX, code);
471
472	WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning",
473	    (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???");
474	mtx_assert(&sched_lock, MA_NOTOWNED);
475	mtx_assert(&Giant, MA_NOTOWNED);
476}
477
478static int
479trap_pfault(struct trapframe *frame, int user)
480{
481	vm_offset_t	eva, va;
482	struct		thread *td;
483	struct		proc *p;
484	vm_map_t	map;
485	vm_prot_t	ftype;
486	int		rv;
487	u_int		user_sr;
488
489	td = curthread;
490	p = td->td_proc;
491	if (frame->exc == EXC_ISI) {
492		eva = frame->srr0;
493		ftype = VM_PROT_READ | VM_PROT_EXECUTE;
494	} else {
495		eva = frame->dar;
496		if (frame->dsisr & DSISR_STORE)
497			ftype = VM_PROT_WRITE;
498		else
499			ftype = VM_PROT_READ;
500	}
501
502	if (user) {
503		map = &p->p_vmspace->vm_map;
504	} else {
505		if ((eva >> ADDR_SR_SHFT) == USER_SR) {
506			if (p->p_vmspace == NULL)
507				return (SIGSEGV);
508
509			__asm ("mfsr %0, %1"
510			    : "=r"(user_sr)
511			    : "K"(USER_SR));
512			eva &= ADDR_PIDX | ADDR_POFF;
513			eva |= user_sr << ADDR_SR_SHFT;
514			map = &p->p_vmspace->vm_map;
515		} else {
516			map = kernel_map;
517		}
518	}
519	va = trunc_page(eva);
520
521	if (map != kernel_map) {
522		/*
523		 * Keep swapout from messing with us during this
524		 *	critical time.
525		 */
526		PROC_LOCK(p);
527		++p->p_lock;
528		PROC_UNLOCK(p);
529
530		/* Fault in the user page: */
531		rv = vm_fault(map, va, ftype,
532		      (ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
533					      : VM_FAULT_NORMAL);
534
535		PROC_LOCK(p);
536		--p->p_lock;
537		PROC_UNLOCK(p);
538	} else {
539		/*
540		 * Don't have to worry about process locking or stacks in the
541		 * kernel.
542		 */
543		rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
544	}
545
546	if (rv == KERN_SUCCESS)
547		return (0);
548
549	if (!user && handle_onfault(frame))
550		return (0);
551
552	return (SIGSEGV);
553}
554
555static __inline void
556setusr(u_int content)
557{
558	__asm __volatile ("isync; mtsr %0,%1; isync"
559		      :: "n"(USER_SR), "r"(content));
560}
561
562int
563badaddr(void *addr, size_t size)
564{
565	return (badaddr_read(addr, size, NULL));
566}
567
568int
569badaddr_read(void *addr, size_t size, int *rptr)
570{
571	struct thread	*td;
572	faultbuf	env;
573	int		x;
574
575	/* Get rid of any stale machine checks that have been waiting.  */
576	__asm __volatile ("sync; isync");
577
578	td = PCPU_GET(curthread);
579
580	if (setfault(env)) {
581		td->td_pcb->pcb_onfault = 0;
582		__asm __volatile ("sync");
583		return 1;
584	}
585
586	__asm __volatile ("sync");
587
588	switch (size) {
589	case 1:
590		x = *(volatile int8_t *)addr;
591		break;
592	case 2:
593		x = *(volatile int16_t *)addr;
594		break;
595	case 4:
596		x = *(volatile int32_t *)addr;
597		break;
598	default:
599		panic("badaddr: invalid size (%d)", size);
600	}
601
602	/* Make sure we took the machine check, if we caused one. */
603	__asm __volatile ("sync; isync");
604
605	td->td_pcb->pcb_onfault = 0;
606	__asm __volatile ("sync");	/* To be sure. */
607
608	/* Use the value to avoid reorder. */
609	if (rptr)
610		*rptr = x;
611
612	return (0);
613}
614
615/*
616 * For now, this only deals with the particular unaligned access case
617 * that gcc tends to generate.  Eventually it should handle all of the
618 * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
619 */
620
621static int
622fix_unaligned(struct thread *td, struct trapframe *frame)
623{
624	struct thread	*fputhread;
625	int		indicator, reg;
626	double		*fpr;
627
628	indicator = EXC_ALI_OPCODE_INDICATOR(frame->dsisr);
629
630	switch (indicator) {
631	case EXC_ALI_LFD:
632	case EXC_ALI_STFD:
633		reg = EXC_ALI_RST(frame->dsisr);
634		fpr = &td->td_pcb->pcb_fpu.fpr[reg];
635		fputhread = PCPU_GET(fputhread);
636
637		/* Juggle the FPU to ensure that we've initialized
638		 * the FPRs, and that their current state is in
639		 * the PCB.
640		 */
641		if (fputhread != td) {
642			if (fputhread)
643				save_fpu(fputhread);
644			enable_fpu(td);
645		}
646		save_fpu(td);
647
648		if (indicator == EXC_ALI_LFD) {
649			if (copyin((void *)frame->dar, fpr,
650			    sizeof(double)) != 0)
651				return -1;
652			enable_fpu(td);
653		} else {
654			if (copyout(fpr, (void *)frame->dar,
655			    sizeof(double)) != 0)
656				return -1;
657		}
658		return 0;
659		break;
660	}
661
662	return -1;
663}
664