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("$FreeBSD$");
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/ptrace.h>
47 #include <sys/reboot.h>
48 #include <sys/syscall.h>
49 #include <sys/sysent.h>
50 #include <sys/systm.h>
51 #include <sys/uio.h>
52 #include <sys/signalvar.h>
53 #ifdef KTRACE
54 #include <sys/ktrace.h>
55 #endif
56 #include <sys/vmmeter.h>
57
58 #include <security/audit/audit.h>
59
60 #include <vm/vm.h>
61 #include <vm/pmap.h>
62 #include <vm/vm_extern.h>
63 #include <vm/vm_param.h>
64 #include <vm/vm_kern.h>
65 #include <vm/vm_map.h>
66 #include <vm/vm_page.h>
67
68 #include <machine/cpu.h>
69 #include <machine/db_machdep.h>
70 #include <machine/fpu.h>
71 #include <machine/frame.h>
72 #include <machine/pcb.h>
73 #include <machine/pmap.h>
74 #include <machine/psl.h>
75 #include <machine/trap.h>
76 #include <machine/spr.h>
77 #include <machine/sr.h>
78
79 static void trap_fatal(struct trapframe *frame);
80 static void printtrap(u_int vector, struct trapframe *frame, int isfatal,
81 int user);
82 static int trap_pfault(struct trapframe *frame, int user);
83 static int fix_unaligned(struct thread *td, struct trapframe *frame);
84 static int handle_onfault(struct trapframe *frame);
85 static void syscall(struct trapframe *frame);
86
87 static __inline void setusr(u_int);
88
89 int setfault(faultbuf); /* defined in locore.S */
90
91 /* Why are these not defined in a header? */
92 int badaddr(void *, size_t);
93 int badaddr_read(void *, size_t, int *);
94
95 extern char *syscallnames[];
96
97 struct powerpc_exception {
98 u_int vector;
99 char *name;
100 };
101
102 static struct powerpc_exception powerpc_exceptions[] = {
103 { 0x0100, "system reset" },
104 { 0x0200, "machine check" },
105 { 0x0300, "data storage interrupt" },
106 { 0x0400, "instruction storage interrupt" },
107 { 0x0500, "external interrupt" },
108 { 0x0600, "alignment" },
109 { 0x0700, "program" },
110 { 0x0800, "floating-point unavailable" },
111 { 0x0900, "decrementer" },
112 { 0x0c00, "system call" },
113 { 0x0d00, "trace" },
114 { 0x0e00, "floating-point assist" },
115 { 0x0f00, "performance monitoring" },
116 { 0x0f20, "altivec unavailable" },
117 { 0x1000, "instruction tlb miss" },
118 { 0x1100, "data load tlb miss" },
119 { 0x1200, "data store tlb miss" },
120 { 0x1300, "instruction breakpoint" },
121 { 0x1400, "system management" },
122 { 0x1600, "altivec assist" },
123 { 0x1700, "thermal management" },
124 { 0x2000, "run mode/trace" },
125 { 0x3000, NULL }
126 };
127
128 static const char *
129 trapname(u_int vector)
130 {
131 struct powerpc_exception *pe;
132
133 for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) {
134 if (pe->vector == vector)
135 return (pe->name);
136 }
137
138 return ("unknown");
139 }
140
141 void
142 trap(struct trapframe *frame)
143 {
144 struct thread *td;
145 struct proc *p;
146 int sig, type, user;
147 u_int ucode;
148 ksiginfo_t ksi;
149
150 PCPU_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
159 CTR3(KTR_TRAP, "trap: %s type=%s (%s)", p->p_comm,
160 trapname(type), user ? "user" : "kernel");
161
162 if (user) {
163 td->td_pticks = 0;
164 td->td_frame = frame;
165 if (td->td_ucred != p->p_ucred)
166 cred_update_thread(td);
167
168 /* User Mode Traps */
169 switch (type) {
170 case EXC_RUNMODETRC:
171 case EXC_TRC:
172 frame->srr1 &= ~PSL_SE;
173 sig = SIGTRAP;
174 break;
175
176 case EXC_DSI:
177 case EXC_ISI:
178 sig = trap_pfault(frame, 1);
179 break;
180
181 case EXC_SC:
182 syscall(frame);
183 break;
184
185 case EXC_FPU:
186 KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU,
187 ("FPU already enabled for thread"));
188 enable_fpu(td);
189 break;
190
191 #ifdef ALTIVEC
192 case EXC_VEC:
193 if ((vecthread = PCPU_GET(vecthread)) != NULL) {
194 KASSERT(vecthread != td,
195 ("altivec already enabled"));
196 save_vec(vecthread);
197 }
198 PCPU_SET(vecthread, td);
199 td->td_pcb->pcb_veccpu = PCPU_GET(cpuid);
200 enable_vec(td);
201 frame->srr1 |= PSL_VEC;
202 break;
203 #else
204 case EXC_VEC:
205 case EXC_VECAST:
206 sig = SIGILL;
207 break;
208 #endif /* ALTIVEC */
209
210 case EXC_ALI:
211 if (fix_unaligned(td, frame) != 0)
212 sig = SIGBUS;
213 else
214 frame->srr0 += 4;
215 break;
216
217 case EXC_PGM:
218 /* XXX temporarily */
219 /* XXX: Magic Number? */
220 if (frame->srr1 & 0x0002000)
221 sig = SIGTRAP;
222 else
223 sig = SIGILL;
224 break;
225
226 default:
227 trap_fatal(frame);
228 }
229 } else {
230 /* Kernel Mode Traps */
231
232 KASSERT(cold || td->td_ucred != NULL,
233 ("kernel trap doesn't have ucred"));
234 switch (type) {
235 case EXC_DSI:
236 if (trap_pfault(frame, 0) == 0)
237 return;
238 break;
239 case EXC_MCHK:
240 if (handle_onfault(frame))
241 return;
242 break;
243 default:
244 break;
245 }
246 trap_fatal(frame);
247 }
248
249 #ifdef ALTIVEC
250 if (td != PCPU_GET(vecthread) ||
251 td->td_pcb->pcb_veccpu != PCPU_GET(cpuid))
252 frame->srr1 &= ~PSL_VEC;
253 #endif /* ALTIVEC */
254
255 if (sig != 0) {
256 if (p->p_sysent->sv_transtrap != NULL)
257 sig = (p->p_sysent->sv_transtrap)(sig, type);
258 ksiginfo_init_trap(&ksi);
259 ksi.ksi_signo = sig;
260 ksi.ksi_code = (int) ucode; /* XXX, not POSIX */
261 /* ksi.ksi_addr = ? */
262 ksi.ksi_trapno = type;
263 trapsignal(td, &ksi);
264 }
265
266 userret(td, frame);
267 mtx_assert(&Giant, MA_NOTOWNED);
268 }
269
270 static void
271 trap_fatal(struct trapframe *frame)
272 {
273
274 printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR));
275 #ifdef KDB
276 if ((debugger_on_panic || kdb_active) &&
277 kdb_trap(frame->exc, 0, frame))
278 return;
279 #endif
280 panic("%s trap", trapname(frame->exc));
281 }
282
283 static void
284 printtrap(u_int vector, struct trapframe *frame, int isfatal, int user)
285 {
286
287 printf("\n");
288 printf("%s %s trap:\n", isfatal ? "fatal" : "handled",
289 user ? "user" : "kernel");
290 printf("\n");
291 printf(" exception = 0x%x (%s)\n", vector >> 8,
292 trapname(vector));
293 switch (vector) {
294 case EXC_DSI:
295 printf(" virtual address = 0x%x\n", frame->dar);
296 break;
297 case EXC_ISI:
298 printf(" virtual address = 0x%x\n", frame->srr0);
299 break;
300 }
301 printf(" srr0 = 0x%x\n", frame->srr0);
302 printf(" srr1 = 0x%x\n", frame->srr1);
303 printf(" curthread = %p\n", curthread);
304 if (curthread != NULL)
305 printf(" pid = %d, comm = %s\n",
306 curthread->td_proc->p_pid, curthread->td_proc->p_comm);
307 printf("\n");
308 }
309
310 /*
311 * Handles a fatal fault when we have onfault state to recover. Returns
312 * non-zero if there was onfault recovery state available.
313 */
314 static int
315 handle_onfault(struct trapframe *frame)
316 {
317 struct thread *td;
318 faultbuf *fb;
319
320 td = curthread;
321 fb = td->td_pcb->pcb_onfault;
322 if (fb != NULL) {
323 frame->srr0 = (*fb)[0];
324 frame->fixreg[1] = (*fb)[1];
325 frame->fixreg[2] = (*fb)[2];
326 frame->fixreg[3] = 1;
327 frame->cr = (*fb)[3];
328 bcopy(&(*fb)[4], &frame->fixreg[13],
329 19 * sizeof(register_t));
330 return (1);
331 }
332 return (0);
333 }
334
335 void
336 syscall(struct trapframe *frame)
337 {
338 caddr_t params;
339 struct sysent *callp;
340 struct thread *td;
341 struct proc *p;
342 int error, n;
343 size_t narg;
344 register_t args[10];
345 u_int code;
346
347 td = PCPU_GET(curthread);
348 p = td->td_proc;
349
350 PCPU_INC(cnt.v_syscall);
351
352 #ifdef KSE
353 if (p->p_flag & P_SA)
354 thread_user_enter(td);
355 #endif
356
357 code = frame->fixreg[0];
358 params = (caddr_t)(frame->fixreg + FIRSTARG);
359 n = NARGREG;
360
361 if (p->p_sysent->sv_prepsyscall) {
362 /*
363 * The prep code is MP aware.
364 */
365 (*p->p_sysent->sv_prepsyscall)(frame, args, &code, ¶ms);
366 } else if (code == SYS_syscall) {
367 /*
368 * code is first argument,
369 * followed by actual args.
370 */
371 code = *(u_int *) params;
372 params += sizeof(register_t);
373 n -= 1;
374 } else if (code == SYS___syscall) {
375 /*
376 * Like syscall, but code is a quad,
377 * so as to maintain quad alignment
378 * for the rest of the args.
379 */
380 params += sizeof(register_t);
381 code = *(u_int *) params;
382 params += sizeof(register_t);
383 n -= 2;
384 }
385
386 if (p->p_sysent->sv_mask)
387 code &= p->p_sysent->sv_mask;
388
389 if (code >= p->p_sysent->sv_size)
390 callp = &p->p_sysent->sv_table[0];
391 else
392 callp = &p->p_sysent->sv_table[code];
393
394 narg = callp->sy_narg;
395
396 if (narg > n) {
397 bcopy(params, args, n * sizeof(register_t));
398 error = copyin(MOREARGS(frame->fixreg[1]), args + n,
399 (narg - n) * sizeof(register_t));
400 params = (caddr_t)args;
401 } else
402 error = 0;
403
404 CTR5(KTR_SYSC, "syscall: p=%s %s(%x %x %x)", p->p_comm,
405 syscallnames[code],
406 frame->fixreg[FIRSTARG],
407 frame->fixreg[FIRSTARG+1],
408 frame->fixreg[FIRSTARG+2]);
409
410 #ifdef KTRACE
411 if (KTRPOINT(td, KTR_SYSCALL))
412 ktrsyscall(code, narg, (register_t *)params);
413 #endif
414
415 td->td_syscalls++;
416
417 if (error == 0) {
418 td->td_retval[0] = 0;
419 td->td_retval[1] = frame->fixreg[FIRSTARG + 1];
420
421 STOPEVENT(p, S_SCE, narg);
422
423 PTRACESTOP_SC(p, td, S_PT_SCE);
424
425 AUDIT_SYSCALL_ENTER(code, td);
426 error = (*callp->sy_call)(td, params);
427 AUDIT_SYSCALL_EXIT(error, td);
428
429 CTR3(KTR_SYSC, "syscall: p=%s %s ret=%x", p->p_comm,
430 syscallnames[code], td->td_retval[0]);
431 }
432 switch (error) {
433 case 0:
434 if (frame->fixreg[0] == SYS___syscall &&
435 code != SYS_freebsd6_lseek && code != SYS_lseek) {
436 /*
437 * 64-bit return, 32-bit syscall. Fixup byte order
438 */
439 frame->fixreg[FIRSTARG] = 0;
440 frame->fixreg[FIRSTARG + 1] = td->td_retval[0];
441 } else {
442 frame->fixreg[FIRSTARG] = td->td_retval[0];
443 frame->fixreg[FIRSTARG + 1] = td->td_retval[1];
444 }
445 /* XXX: Magic number */
446 frame->cr &= ~0x10000000;
447 break;
448 case ERESTART:
449 /*
450 * Set user's pc back to redo the system call.
451 */
452 frame->srr0 -= 4;
453 break;
454 case EJUSTRETURN:
455 /* nothing to do */
456 break;
457 default:
458 if (p->p_sysent->sv_errsize) {
459 if (error >= p->p_sysent->sv_errsize)
460 error = -1; /* XXX */
461 else
462 error = p->p_sysent->sv_errtbl[error];
463 }
464 frame->fixreg[FIRSTARG] = error;
465 /* XXX: Magic number: Carry Flag Equivalent? */
466 frame->cr |= 0x10000000;
467 break;
468 }
469
470 /*
471 * Check for misbehavior.
472 */
473 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning",
474 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???");
475 KASSERT(td->td_critnest == 0,
476 ("System call %s returning in a critical section",
477 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???"));
478 KASSERT(td->td_locks == 0,
479 ("System call %s returning with %d locks held",
480 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???",
481 td->td_locks));
482
483 #ifdef KTRACE
484 if (KTRPOINT(td, KTR_SYSRET))
485 ktrsysret(code, error, td->td_retval[0]);
486 #endif
487
488 /*
489 * Does the comment in the i386 code about errno apply here?
490 */
491 STOPEVENT(p, S_SCX, code);
492
493 PTRACESTOP_SC(p, td, S_PT_SCX);
494 }
495
496 static int
497 trap_pfault(struct trapframe *frame, int user)
498 {
499 vm_offset_t eva, va;
500 struct thread *td;
501 struct proc *p;
502 vm_map_t map;
503 vm_prot_t ftype;
504 int rv;
505 u_int user_sr;
506
507 td = curthread;
508 p = td->td_proc;
509 if (frame->exc == EXC_ISI) {
510 eva = frame->srr0;
511 ftype = VM_PROT_READ | VM_PROT_EXECUTE;
512 } else {
513 eva = frame->dar;
514 if (frame->dsisr & DSISR_STORE)
515 ftype = VM_PROT_WRITE;
516 else
517 ftype = VM_PROT_READ;
518 }
519
520 if (user) {
521 map = &p->p_vmspace->vm_map;
522 } else {
523 if ((eva >> ADDR_SR_SHFT) == USER_SR) {
524 if (p->p_vmspace == NULL)
525 return (SIGSEGV);
526
527 __asm ("mfsr %0, %1"
528 : "=r"(user_sr)
529 : "K"(USER_SR));
530 eva &= ADDR_PIDX | ADDR_POFF;
531 eva |= user_sr << ADDR_SR_SHFT;
532 map = &p->p_vmspace->vm_map;
533 } else {
534 map = kernel_map;
535 }
536 }
537 va = trunc_page(eva);
538
539 if (map != kernel_map) {
540 /*
541 * Keep swapout from messing with us during this
542 * critical time.
543 */
544 PROC_LOCK(p);
545 ++p->p_lock;
546 PROC_UNLOCK(p);
547
548 /* Fault in the user page: */
549 rv = vm_fault(map, va, ftype,
550 (ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
551 : VM_FAULT_NORMAL);
552
553 PROC_LOCK(p);
554 --p->p_lock;
555 PROC_UNLOCK(p);
556 } else {
557 /*
558 * Don't have to worry about process locking or stacks in the
559 * kernel.
560 */
561 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
562 }
563
564 if (rv == KERN_SUCCESS)
565 return (0);
566
567 if (!user && handle_onfault(frame))
568 return (0);
569
570 return (SIGSEGV);
571 }
572
573 static __inline void
574 setusr(u_int content)
575 {
576 __asm __volatile ("isync; mtsr %0,%1; isync"
577 :: "n"(USER_SR), "r"(content));
578 }
579
580 int
581 badaddr(void *addr, size_t size)
582 {
583 return (badaddr_read(addr, size, NULL));
584 }
585
586 int
587 badaddr_read(void *addr, size_t size, int *rptr)
588 {
589 struct thread *td;
590 faultbuf env;
591 int x;
592
593 /* Get rid of any stale machine checks that have been waiting. */
594 __asm __volatile ("sync; isync");
595
596 td = PCPU_GET(curthread);
597
598 if (setfault(env)) {
599 td->td_pcb->pcb_onfault = 0;
600 __asm __volatile ("sync");
601 return 1;
602 }
603
604 __asm __volatile ("sync");
605
606 switch (size) {
607 case 1:
608 x = *(volatile int8_t *)addr;
609 break;
610 case 2:
611 x = *(volatile int16_t *)addr;
612 break;
613 case 4:
614 x = *(volatile int32_t *)addr;
615 break;
616 default:
617 panic("badaddr: invalid size (%d)", size);
618 }
619
620 /* Make sure we took the machine check, if we caused one. */
621 __asm __volatile ("sync; isync");
622
623 td->td_pcb->pcb_onfault = 0;
624 __asm __volatile ("sync"); /* To be sure. */
625
626 /* Use the value to avoid reorder. */
627 if (rptr)
628 *rptr = x;
629
630 return (0);
631 }
632
633 /*
634 * For now, this only deals with the particular unaligned access case
635 * that gcc tends to generate. Eventually it should handle all of the
636 * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
637 */
638
639 static int
640 fix_unaligned(struct thread *td, struct trapframe *frame)
641 {
642 struct thread *fputhread;
643 int indicator, reg;
644 double *fpr;
645
646 indicator = EXC_ALI_OPCODE_INDICATOR(frame->dsisr);
647
648 switch (indicator) {
649 case EXC_ALI_LFD:
650 case EXC_ALI_STFD:
651 reg = EXC_ALI_RST(frame->dsisr);
652 fpr = &td->td_pcb->pcb_fpu.fpr[reg];
653 fputhread = PCPU_GET(fputhread);
654
655 /* Juggle the FPU to ensure that we've initialized
656 * the FPRs, and that their current state is in
657 * the PCB.
658 */
659 if (fputhread != td) {
660 if (fputhread)
661 save_fpu(fputhread);
662 enable_fpu(td);
663 }
664 save_fpu(td);
665
666 if (indicator == EXC_ALI_LFD) {
667 if (copyin((void *)frame->dar, fpr,
668 sizeof(double)) != 0)
669 return -1;
670 enable_fpu(td);
671 } else {
672 if (copyout(fpr, (void *)frame->dar,
673 sizeof(double)) != 0)
674 return -1;
675 }
676 return 0;
677 break;
678 }
679
680 return -1;
681 }
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