summaryrefslogtreecommitdiffstats
path: root/sys/powerpc/aim/trap.c
blob: b691a65b81297d170ef849ace178050c759636b7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
/*-
 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
 * Copyright (C) 1995, 1996 TooLs GmbH.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by TooLs GmbH.
 * 4. The name of TooLs GmbH may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $NetBSD: trap.c,v 1.58 2002/03/04 04:07:35 dbj Exp $
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_ktrace.h"

#include <sys/param.h>
#include <sys/kdb.h>
#include <sys/proc.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/pioctl.h>
#include <sys/ptrace.h>
#include <sys/reboot.h>
#include <sys/syscall.h>
#include <sys/sysent.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/signalvar.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <sys/vmmeter.h>

#include <security/audit/audit.h>

#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>

#include <machine/cpu.h>
#include <machine/db_machdep.h>
#include <machine/fpu.h>
#include <machine/frame.h>
#include <machine/pcb.h>
#include <machine/pmap.h>
#include <machine/psl.h>
#include <machine/trap.h>
#include <machine/spr.h>
#include <machine/sr.h>

static void	trap_fatal(struct trapframe *frame);
static void	printtrap(u_int vector, struct trapframe *frame, int isfatal,
		    int user);
static int	trap_pfault(struct trapframe *frame, int user);
static int	fix_unaligned(struct thread *td, struct trapframe *frame);
static int	handle_onfault(struct trapframe *frame);
static void	syscall(struct trapframe *frame);

static __inline void	setusr(u_int);

int	setfault(faultbuf);		/* defined in locore.S */

/* Why are these not defined in a header? */
int	badaddr(void *, size_t);
int	badaddr_read(void *, size_t, int *);

extern char	*syscallnames[];

struct powerpc_exception {
	u_int	vector;
	char	*name;
};

static struct powerpc_exception powerpc_exceptions[] = {
	{ 0x0100, "system reset" },
	{ 0x0200, "machine check" },
	{ 0x0300, "data storage interrupt" },
	{ 0x0400, "instruction storage interrupt" },
	{ 0x0500, "external interrupt" },
	{ 0x0600, "alignment" },
	{ 0x0700, "program" },
	{ 0x0800, "floating-point unavailable" },
	{ 0x0900, "decrementer" },
	{ 0x0c00, "system call" },
	{ 0x0d00, "trace" },
	{ 0x0e00, "floating-point assist" },
	{ 0x0f00, "performance monitoring" },
	{ 0x0f20, "altivec unavailable" },
	{ 0x1000, "instruction tlb miss" },
	{ 0x1100, "data load tlb miss" },
	{ 0x1200, "data store tlb miss" },
	{ 0x1300, "instruction breakpoint" },
	{ 0x1400, "system management" },
	{ 0x1600, "altivec assist" },
	{ 0x1700, "thermal management" },
	{ 0x2000, "run mode/trace" },
	{ 0x3000, NULL }
};

static const char *
trapname(u_int vector)
{
	struct	powerpc_exception *pe;

	for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) {
		if (pe->vector == vector)
			return (pe->name);
	}

	return ("unknown");
}

void
trap(struct trapframe *frame)
{
	struct thread	*td;
	struct proc	*p;
	int		sig, type, user;
	u_int		ucode;
	ksiginfo_t	ksi;

	PCPU_INC(cnt.v_trap);

	td = PCPU_GET(curthread);
	p = td->td_proc;

	type = ucode = frame->exc;
	sig = 0;
	user = frame->srr1 & PSL_PR;

	CTR3(KTR_TRAP, "trap: %s type=%s (%s)", td->td_name,
	    trapname(type), user ? "user" : "kernel");

	if (user) {
		td->td_pticks = 0;
		td->td_frame = frame;
		if (td->td_ucred != p->p_ucred)
			cred_update_thread(td);

		/* User Mode Traps */
		switch (type) {
		case EXC_RUNMODETRC:
		case EXC_TRC:
			frame->srr1 &= ~PSL_SE;
			sig = SIGTRAP;
			break;

		case EXC_DSI:
		case EXC_ISI:
			sig = trap_pfault(frame, 1);
			break;

		case EXC_SC:
			syscall(frame);
			break;

		case EXC_FPU:
			KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU,
			    ("FPU already enabled for thread"));
			enable_fpu(td);
			break;

#ifdef	ALTIVEC
		case EXC_VEC:
			if ((vecthread = PCPU_GET(vecthread)) != NULL) {
				KASSERT(vecthread != td,
				    ("altivec already enabled"));
				save_vec(vecthread);
			}
			PCPU_SET(vecthread, td);
			td->td_pcb->pcb_veccpu = PCPU_GET(cpuid);
			enable_vec(td);
			frame->srr1 |= PSL_VEC;
			break;
#else
		case EXC_VEC:
		case EXC_VECAST:
			sig = SIGILL;
			break;
#endif /* ALTIVEC */

		case EXC_ALI:
			if (fix_unaligned(td, frame) != 0)
				sig = SIGBUS;
			else
				frame->srr0 += 4;
			break;

		case EXC_PGM:
			/* XXX temporarily */
			/* XXX: Magic Number? */
			if (frame->srr1 & 0x0002000)
				sig = SIGTRAP;
 			else
				sig = SIGILL;
			break;

		default:
			trap_fatal(frame);
		}
	} else {
		/* Kernel Mode Traps */

		KASSERT(cold || td->td_ucred != NULL,
		    ("kernel trap doesn't have ucred"));
		switch (type) {
		case EXC_DSI:
			if (trap_pfault(frame, 0) == 0)
 				return;
			break;
		case EXC_MCHK:
			if (handle_onfault(frame))
 				return;
			break;
		default:
			break;
		}
		trap_fatal(frame);
	}

#ifdef	ALTIVEC
	if (td != PCPU_GET(vecthread) ||
	    td->td_pcb->pcb_veccpu != PCPU_GET(cpuid))
		frame->srr1 &= ~PSL_VEC;
#endif /* ALTIVEC */

	if (sig != 0) {
		if (p->p_sysent->sv_transtrap != NULL)
			sig = (p->p_sysent->sv_transtrap)(sig, type);
		ksiginfo_init_trap(&ksi);
		ksi.ksi_signo = sig;
		ksi.ksi_code = (int) ucode; /* XXX, not POSIX */
		/* ksi.ksi_addr = ? */
		ksi.ksi_trapno = type;
		trapsignal(td, &ksi);
	}

	userret(td, frame);
	mtx_assert(&Giant, MA_NOTOWNED);
}

static void
trap_fatal(struct trapframe *frame)
{

	printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR));
#ifdef KDB
	if ((debugger_on_panic || kdb_active) &&
	    kdb_trap(frame->exc, 0, frame))
		return;
#endif
	panic("%s trap", trapname(frame->exc));
}

static void
printtrap(u_int vector, struct trapframe *frame, int isfatal, int user)
{

	printf("\n");
	printf("%s %s trap:\n", isfatal ? "fatal" : "handled",
	    user ? "user" : "kernel");
	printf("\n");
	printf("   exception       = 0x%x (%s)\n", vector >> 8,
	    trapname(vector));
	switch (vector) {
	case EXC_DSI:
		printf("   virtual address = 0x%x\n", frame->dar);
		break;
	case EXC_ISI:
		printf("   virtual address = 0x%x\n", frame->srr0);
		break;
	}
	printf("   srr0            = 0x%x\n", frame->srr0);
	printf("   srr1            = 0x%x\n", frame->srr1);
	printf("   curthread       = %p\n", curthread);
	if (curthread != NULL)
		printf("          pid = %d, comm = %s\n",
		    curthread->td_proc->p_pid, curthread->td_name);
	printf("\n");
}

/*
 * Handles a fatal fault when we have onfault state to recover.  Returns
 * non-zero if there was onfault recovery state available.
 */
static int
handle_onfault(struct trapframe *frame)
{
	struct		thread *td;
	faultbuf	*fb;

	td = curthread;
	fb = td->td_pcb->pcb_onfault;
	if (fb != NULL) {
		frame->srr0 = (*fb)[0];
		frame->fixreg[1] = (*fb)[1];
		frame->fixreg[2] = (*fb)[2];
		frame->fixreg[3] = 1;
		frame->cr = (*fb)[3];
		bcopy(&(*fb)[4], &frame->fixreg[13],
		    19 * sizeof(register_t));
		return (1);
	}
	return (0);
}

void
syscall(struct trapframe *frame)
{
	caddr_t		params;
	struct		sysent *callp;
	struct		thread *td;
	struct		proc *p;
	int		error, n;
	size_t		narg;
	register_t	args[10];
	u_int		code;

	td = PCPU_GET(curthread);
	p = td->td_proc;

	PCPU_INC(cnt.v_syscall);

#ifdef KSE
	if (p->p_flag & P_SA)
		thread_user_enter(td);
#endif

	code = frame->fixreg[0];
	params = (caddr_t)(frame->fixreg + FIRSTARG);
	n = NARGREG;

	if (p->p_sysent->sv_prepsyscall) {
		/*
		 * The prep code is MP aware.
		 */
		(*p->p_sysent->sv_prepsyscall)(frame, args, &code, &params);
	} else if (code == SYS_syscall) {
		/*
		 * code is first argument,
		 * followed by actual args.
		 */
		code = *(u_int *) params;
		params += sizeof(register_t);
		n -= 1;
	} else if (code == SYS___syscall) {
		/*
		 * Like syscall, but code is a quad,
		 * so as to maintain quad alignment
		 * for the rest of the args.
		 */
		params += sizeof(register_t);
		code = *(u_int *) params;
		params += sizeof(register_t);
		n -= 2;
	}

 	if (p->p_sysent->sv_mask)
 		code &= p->p_sysent->sv_mask;

 	if (code >= p->p_sysent->sv_size)
 		callp = &p->p_sysent->sv_table[0];
  	else
 		callp = &p->p_sysent->sv_table[code];

	narg = callp->sy_narg;

	if (narg > n) {
		bcopy(params, args, n * sizeof(register_t));
		error = copyin(MOREARGS(frame->fixreg[1]), args + n,
			       (narg - n) * sizeof(register_t));
		params = (caddr_t)args;
	} else
		error = 0;

	CTR5(KTR_SYSC, "syscall: p=%s %s(%x %x %x)", td->td_name,
	     syscallnames[code],
	     frame->fixreg[FIRSTARG],
	     frame->fixreg[FIRSTARG+1],
	     frame->fixreg[FIRSTARG+2]);

#ifdef	KTRACE
	if (KTRPOINT(td, KTR_SYSCALL))
		ktrsyscall(code, narg, (register_t *)params);
#endif

	td->td_syscalls++;

	if (error == 0) {
		td->td_retval[0] = 0;
		td->td_retval[1] = frame->fixreg[FIRSTARG + 1];

		STOPEVENT(p, S_SCE, narg);

		PTRACESTOP_SC(p, td, S_PT_SCE);

		AUDIT_SYSCALL_ENTER(code, td);
		error = (*callp->sy_call)(td, params);
		AUDIT_SYSCALL_EXIT(error, td);

		CTR3(KTR_SYSC, "syscall: p=%s %s ret=%x", td->td_name,
		     syscallnames[code], td->td_retval[0]);
	}
	switch (error) {
	case 0:
		if (frame->fixreg[0] == SYS___syscall &&
		    code != SYS_freebsd6_lseek && code != SYS_lseek) {
			/*
			 * 64-bit return, 32-bit syscall. Fixup byte order
			 */
			frame->fixreg[FIRSTARG] = 0;
			frame->fixreg[FIRSTARG + 1] = td->td_retval[0];
		} else {
			frame->fixreg[FIRSTARG] = td->td_retval[0];
			frame->fixreg[FIRSTARG + 1] = td->td_retval[1];
		}
		/* XXX: Magic number */
		frame->cr &= ~0x10000000;
		break;
	case ERESTART:
		/*
		 * Set user's pc back to redo the system call.
		 */
		frame->srr0 -= 4;
		break;
	case EJUSTRETURN:
		/* nothing to do */
		break;
	default:
		if (p->p_sysent->sv_errsize) {
			if (error >= p->p_sysent->sv_errsize)
				error = -1;	/* XXX */
			else
				error = p->p_sysent->sv_errtbl[error];
		}
		frame->fixreg[FIRSTARG] = error;
		/* XXX: Magic number: Carry Flag Equivalent? */
		frame->cr |= 0x10000000;
		break;
	}

	/*
	 * Check for misbehavior.
	 */
	WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning",
	    (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???");
	KASSERT(td->td_critnest == 0,
	    ("System call %s returning in a critical section",
	    (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???"));
	KASSERT(td->td_locks == 0,
	    ("System call %s returning with %d locks held",
	    (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???",
	    td->td_locks));

#ifdef	KTRACE
	if (KTRPOINT(td, KTR_SYSRET))
		ktrsysret(code, error, td->td_retval[0]);
#endif

	/*
	 * Does the comment in the i386 code about errno apply here?
	 */
	STOPEVENT(p, S_SCX, code);
 
	PTRACESTOP_SC(p, td, S_PT_SCX);
}

static int
trap_pfault(struct trapframe *frame, int user)
{
	vm_offset_t	eva, va;
	struct		thread *td;
	struct		proc *p;
	vm_map_t	map;
	vm_prot_t	ftype;
	int		rv;
	u_int		user_sr;

	td = curthread;
	p = td->td_proc;
	if (frame->exc == EXC_ISI) {
		eva = frame->srr0;
		ftype = VM_PROT_READ | VM_PROT_EXECUTE;
	} else {
		eva = frame->dar;
		if (frame->dsisr & DSISR_STORE)
			ftype = VM_PROT_WRITE;
		else
			ftype = VM_PROT_READ;
	}

	if (user) {
		map = &p->p_vmspace->vm_map;
	} else {
		if ((eva >> ADDR_SR_SHFT) == USER_SR) {
			if (p->p_vmspace == NULL)
				return (SIGSEGV);

			__asm ("mfsr %0, %1"
			    : "=r"(user_sr)
			    : "K"(USER_SR));
			eva &= ADDR_PIDX | ADDR_POFF;
			eva |= user_sr << ADDR_SR_SHFT;
			map = &p->p_vmspace->vm_map;
		} else {
			map = kernel_map;
		}
	}
	va = trunc_page(eva);

	if (map != kernel_map) {
		/*
		 * Keep swapout from messing with us during this
		 *	critical time.
		 */
		PROC_LOCK(p);
		++p->p_lock;
		PROC_UNLOCK(p);

		/* Fault in the user page: */
		rv = vm_fault(map, va, ftype,
		      (ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
					      : VM_FAULT_NORMAL);

		PROC_LOCK(p);
		--p->p_lock;
		PROC_UNLOCK(p);
	} else {
		/*
		 * Don't have to worry about process locking or stacks in the
		 * kernel.
		 */
		rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
	}

	if (rv == KERN_SUCCESS)
		return (0);

	if (!user && handle_onfault(frame))
		return (0);

	return (SIGSEGV);
}

static __inline void
setusr(u_int content)
{
	__asm __volatile ("isync; mtsr %0,%1; isync"
		      :: "n"(USER_SR), "r"(content));
}

int
badaddr(void *addr, size_t size)
{
	return (badaddr_read(addr, size, NULL));
}

int
badaddr_read(void *addr, size_t size, int *rptr)
{
	struct thread	*td;
	faultbuf	env;
	int		x;

	/* Get rid of any stale machine checks that have been waiting.  */
	__asm __volatile ("sync; isync");

	td = PCPU_GET(curthread);

	if (setfault(env)) {
		td->td_pcb->pcb_onfault = 0;
		__asm __volatile ("sync");
		return 1;
	}

	__asm __volatile ("sync");

	switch (size) {
	case 1:
		x = *(volatile int8_t *)addr;
		break;
	case 2:
		x = *(volatile int16_t *)addr;
		break;
	case 4:
		x = *(volatile int32_t *)addr;
		break;
	default:
		panic("badaddr: invalid size (%d)", size);
	}

	/* Make sure we took the machine check, if we caused one. */
	__asm __volatile ("sync; isync");

	td->td_pcb->pcb_onfault = 0;
	__asm __volatile ("sync");	/* To be sure. */

	/* Use the value to avoid reorder. */
	if (rptr)
		*rptr = x;

	return (0);
}

/*
 * For now, this only deals with the particular unaligned access case
 * that gcc tends to generate.  Eventually it should handle all of the
 * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
 */

static int
fix_unaligned(struct thread *td, struct trapframe *frame)
{
	struct thread	*fputhread;
	int		indicator, reg;
	double		*fpr;

	indicator = EXC_ALI_OPCODE_INDICATOR(frame->dsisr);

	switch (indicator) {
	case EXC_ALI_LFD:
	case EXC_ALI_STFD:
		reg = EXC_ALI_RST(frame->dsisr);
		fpr = &td->td_pcb->pcb_fpu.fpr[reg];
		fputhread = PCPU_GET(fputhread);

		/* Juggle the FPU to ensure that we've initialized
		 * the FPRs, and that their current state is in
		 * the PCB.
		 */
		if (fputhread != td) {
			if (fputhread)
				save_fpu(fputhread);
			enable_fpu(td);
		}
		save_fpu(td);

		if (indicator == EXC_ALI_LFD) {
			if (copyin((void *)frame->dar, fpr,
			    sizeof(double)) != 0)
				return -1;
			enable_fpu(td);
		} else {
			if (copyout(fpr, (void *)frame->dar,
			    sizeof(double)) != 0)
				return -1;
		}
		return 0;
		break;
	}

	return -1;
}
OpenPOWER on IntegriCloud