trap.c revision 173601
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 173601 2007-11-14 06:51:33Z julian $"); 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 79static void trap_fatal(struct trapframe *frame); 80static void printtrap(u_int vector, struct trapframe *frame, int isfatal, 81 int user); 82static int trap_pfault(struct trapframe *frame, int user); 83static int fix_unaligned(struct thread *td, struct trapframe *frame); 84static int handle_onfault(struct trapframe *frame); 85static void syscall(struct trapframe *frame); 86 87static __inline void setusr(u_int); 88 89int setfault(faultbuf); /* defined in locore.S */ 90 91/* Why are these not defined in a header? */ 92int badaddr(void *, size_t); 93int badaddr_read(void *, size_t, int *); 94 95extern char *syscallnames[]; 96 97struct powerpc_exception { 98 u_int vector; 99 char *name; 100}; 101 102static 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 128static const char * 129trapname(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 141void 142trap(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)", td->td_name, 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 270static void 271trap_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 283static void 284printtrap(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_name); 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 */ 314static int 315handle_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 335void 336syscall(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)", td->td_name, 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", td->td_name, 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 496static int 497trap_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 573static __inline void 574setusr(u_int content) 575{ 576 __asm __volatile ("isync; mtsr %0,%1; isync" 577 :: "n"(USER_SR), "r"(content)); 578} 579 580int 581badaddr(void *addr, size_t size) 582{ 583 return (badaddr_read(addr, size, NULL)); 584} 585 586int 587badaddr_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 639static int 640fix_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} 682