trap.c revision 97398
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#ifndef lint 35static const char rcsid[] = 36 "$FreeBSD: head/sys/powerpc/aim/trap.c 97398 2002-05-28 12:28:22Z benno $"; 37#endif /* not lint */ 38 39#include "opt_ddb.h" 40#include "opt_ktrace.h" 41 42#include <sys/param.h> 43#include <sys/proc.h> 44#include <sys/ktr.h> 45#include <sys/lock.h> 46#include <sys/mutex.h> 47#include <sys/pioctl.h> 48#include <sys/reboot.h> 49#include <sys/syscall.h> 50#include <sys/sysent.h> 51#include <sys/systm.h> 52#include <sys/uio.h> 53#include <sys/user.h> 54#ifdef KTRACE 55#include <sys/ktrace.h> 56#endif 57#include <sys/vmmeter.h> 58 59#include <vm/vm.h> 60#include <vm/pmap.h> 61#include <vm/vm_extern.h> 62#include <vm/vm_param.h> 63#include <vm/vm_kern.h> 64#include <vm/vm_map.h> 65#include <vm/vm_page.h> 66 67#include <machine/cpu.h> 68#include <machine/db_machdep.h> 69#include <machine/fpu.h> 70#include <machine/frame.h> 71#include <machine/pcb.h> 72#include <machine/pmap.h> 73#include <machine/psl.h> 74#include <machine/trap.h> 75#include <machine/spr.h> 76#include <machine/sr.h> 77 78#ifndef MULTIPROCESSOR 79extern int intr_depth; 80#endif 81 82void trap(struct trapframe *); 83 84static void trap_fatal(struct trapframe *frame); 85static void printtrap(u_int vector, struct trapframe *frame, int isfatal, 86 int user); 87static int trap_pfault(struct trapframe *frame, int user); 88static int fix_unaligned(struct thread *td, struct trapframe *frame); 89static int handle_onfault(struct trapframe *frame); 90static void syscall(struct trapframe *frame); 91 92static __inline void setusr(u_int); 93 94int setfault(faultbuf); /* defined in locore.S */ 95 96/* Why are these not defined in a header? */ 97int badaddr(void *, size_t); 98int badaddr_read(void *, size_t, int *); 99 100#ifdef WITNESS 101extern char *syscallnames[]; 102#endif 103 104struct powerpc_exception { 105 u_int vector; 106 char *name; 107}; 108 109static struct powerpc_exception powerpc_exceptions[] = { 110 { 0x0100, "system reset" }, 111 { 0x0200, "machine check" }, 112 { 0x0300, "data storage interrupt" }, 113 { 0x0400, "instruction storage interrupt" }, 114 { 0x0500, "external interrupt" }, 115 { 0x0600, "alignment" }, 116 { 0x0700, "program" }, 117 { 0x0800, "floating-point unavailable" }, 118 { 0x0900, "decrementer" }, 119 { 0x0c00, "system call" }, 120 { 0x0d00, "trace" }, 121 { 0x0e00, "floating-point assist" }, 122 { 0x0f00, "performance monitoring" }, 123 { 0x0f20, "altivec unavailable" }, 124 { 0x1000, "instruction tlb miss" }, 125 { 0x1100, "data load tlb miss" }, 126 { 0x1200, "data store tlb miss" }, 127 { 0x1300, "instruction breakpoint" }, 128 { 0x1400, "system management" }, 129 { 0x1600, "altivec assist" }, 130 { 0x1700, "thermal management" }, 131 { 0x2000, "run mode/trace" }, 132 { 0x3000, NULL } 133}; 134 135static const char * 136trapname(u_int vector) 137{ 138 struct powerpc_exception *pe; 139 140 for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) { 141 if (pe->vector == vector) 142 return (pe->name); 143 } 144 145 return ("unknown"); 146} 147 148void 149trap(struct trapframe *frame) 150{ 151 struct thread *td, *fputhread; 152 struct proc *p; 153 int sig, type, user; 154 u_int sticks, ucode; 155 156 atomic_add_int(&cnt.v_trap, 1); 157 158 td = PCPU_GET(curthread); 159 p = td->td_proc; 160 161 type = ucode = frame->exc; 162 sig = 0; 163 user = frame->srr1 & PSL_PR; 164 sticks = 0; 165 166 CTR3(KTR_TRAP, "trap: %s type=%s (%s)", p->p_comm, 167 trapname(type), user ? "user" : "kernel"); 168 169 if (user) { 170 sticks = td->td_kse->ke_sticks; 171 td->td_frame = frame; 172 if (td->td_ucred != p->p_ucred) 173 cred_update_thread(td); 174 175 /* User Mode Traps */ 176 switch (type) { 177 case EXC_RUNMODETRC: 178 case EXC_TRC: 179 frame->srr1 &= ~PSL_SE; 180 sig = SIGTRAP; 181 break; 182 183 case EXC_DSI: 184 case EXC_ISI: 185 sig = trap_pfault(frame, 1); 186 break; 187 188 case EXC_SC: 189 syscall(frame); 190 break; 191 192 case EXC_FPU: 193 if ((fputhread = PCPU_GET(fputhread)) != NULL) { 194 save_fpu(fputhread); 195 } 196 PCPU_SET(fputhread, td); 197 td->td_pcb->pcb_fpcpu = PCPU_GET(cpuid); 198 enable_fpu(td); 199 frame->srr1 |= PSL_FP; 200 break; 201 202#ifdef ALTIVEC 203 case EXC_VEC: 204 if ((vecthread = PCPU_GET(vecthread)) != NULL) { 205 KASSERT(vecthread != td, 206 ("altivec already enabled")); 207 save_vec(vecthread); 208 } 209 PCPU_SET(vecthread, td); 210 td->td_pcb->pcb_veccpu = PCPU_GET(cpuid); 211 enable_vec(td); 212 frame->srr1 |= PSL_VEC; 213 break; 214#endif /* ALTIVEC */ 215 216 case EXC_ALI: 217 if (fix_unaligned(td, frame) != 0) 218 sig = SIGBUS; 219 else 220 frame->srr0 += 4; 221 break; 222 223 case EXC_PGM: 224 /* XXX temporarily */ 225 /* XXX: Magic Number? */ 226 if (frame->srr1 & 0x0002000) 227 sig = SIGTRAP; 228 else 229 sig = SIGILL; 230 break; 231 232 default: 233 trap_fatal(frame); 234 } 235 } else { 236 /* Kernel Mode Traps */ 237 238 KASSERT(cold || td->td_ucred != NULL, 239 ("kernel trap doesn't have ucred")); 240 switch (type) { 241 case EXC_DSI: 242 if (trap_pfault(frame, 0) == 0) 243 return; 244 break; 245 case EXC_MCHK: 246 if (handle_onfault(frame)) 247 return; 248 break; 249 default: 250 trap_fatal(frame); 251 } 252 } 253 254 if (td != PCPU_GET(fputhread) || 255 td->td_pcb->pcb_fpcpu != PCPU_GET(cpuid)) 256 frame->srr1 &= ~PSL_FP; 257 258#ifdef ALTIVEC 259 if (td != PCPU_GET(vecthread) || 260 td->td_pcb->pcb_veccpu != PCPU_GET(cpuid)) 261 frame->srr1 &= ~PSL_VEC; 262#endif /* ALTIVEC */ 263 264 if (sig != 0) { 265 if (p->p_sysent->sv_transtrap != NULL) 266 sig = (p->p_sysent->sv_transtrap)(sig, type); 267 trapsignal(p, sig, ucode); 268 } 269 270 userret(td, frame, sticks); 271 mtx_assert(&Giant, MA_NOTOWNED); 272#ifdef DIAGNOSTIC 273 cred_free_thread(td); 274#endif /* DIAGNOSTIC */ 275} 276 277static void 278trap_fatal(struct trapframe *frame) 279{ 280 281 printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR)); 282#ifdef DDB 283 if ((debugger_on_panic || db_active) && kdb_trap(frame->exc, 0, frame)) 284 return; 285#endif 286 panic("%s trap", trapname(frame->exc)); 287} 288 289static void 290printtrap(u_int vector, struct trapframe *frame, int isfatal, int user) 291{ 292 293 printf("\n"); 294 printf("%s %s trap:\n", isfatal ? "fatal" : "handled", 295 user ? "user" : "kernel"); 296 printf("\n"); 297 printf(" exception = 0x%x (%s)\n", vector >> 8, 298 trapname(vector)); 299 switch (vector) { 300 case EXC_DSI: 301 printf(" virtual address = 0x%x\n", frame->dar); 302 break; 303 case EXC_ISI: 304 printf(" virtual address = 0x%x\n", frame->srr0); 305 break; 306 } 307 printf(" srr0 = 0x%x\n", frame->srr0); 308 printf(" srr1 = 0x%x\n", frame->srr1); 309 printf(" curthread = %p\n", curthread); 310 if (curthread != NULL) 311 printf(" pid = %d, comm = %s\n", 312 curthread->td_proc->p_pid, curthread->td_proc->p_comm); 313 printf("\n"); 314} 315 316/* 317 * Handles a fatal fault when we have onfault state to recover. Returns 318 * non-zero if there was onfault recovery state available. 319 */ 320static int 321handle_onfault(struct trapframe *frame) 322{ 323 struct thread *td; 324 faultbuf *fb; 325 326 td = curthread; 327 fb = td->td_pcb->pcb_onfault; 328 if (fb != NULL) { 329 frame->srr0 = (*fb)[0]; 330 frame->fixreg[1] = (*fb)[1]; 331 frame->fixreg[2] = (*fb)[2]; 332 frame->cr = (*fb)[3]; 333 bcopy(&(*fb)[4], &frame->fixreg[13], 334 19 * sizeof(register_t)); 335 return (1); 336 } 337 return (0); 338} 339 340void 341syscall(struct trapframe *frame) 342{ 343 caddr_t params; 344 struct sysent *callp; 345 struct thread *td; 346 struct proc *p; 347 int error, n; 348 size_t narg; 349 register_t args[10]; 350 u_int code; 351 352 td = PCPU_GET(curthread); 353 p = td->td_proc; 354 355 atomic_add_int(&cnt.v_syscall, 1); 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 = *params++; 372 n -= 1; 373 } else if (code == SYS___syscall) { 374 /* 375 * Like syscall, but code is a quad, 376 * so as to maintain quad alignment 377 * for the rest of the args. 378 */ 379 params++; 380 code = *params++; 381 n -= 2; 382 } 383 384 if (p->p_sysent->sv_mask) 385 code &= p->p_sysent->sv_mask; 386 387 if (code >= p->p_sysent->sv_size) 388 callp = &p->p_sysent->sv_table[0]; 389 else 390 callp = &p->p_sysent->sv_table[code]; 391 392 narg = callp->sy_narg & SYF_ARGMASK; 393 394 if (narg > n * sizeof(register_t)) { 395 bcopy(params, args, n * sizeof(register_t)); 396 error = copyin(MOREARGS(frame->fixreg[1]), args + n, 397 narg - n * sizeof(register_t)); 398 if (error) { 399#ifdef KTRACE 400 /* Can't get all the arguments! */ 401 if (KTRPOINT(p, KTR_SYSCALL)) 402 ktrsyscall(p->p_tracep, code, narg, args); 403#endif 404 goto bad; 405 } 406 params = (caddr_t)args; 407 } 408 409 /* 410 * Try to run the syscall without Giant if the syscall is MP safe. 411 */ 412 if ((callp->sy_narg & SYF_MPSAFE) == 0) 413 mtx_lock(&Giant); 414 415#ifdef KTRACE 416 if (KTRPOINT(p, KTR_SYSCALL)) 417 ktrsyscall(p->p_tracep, code, narg, params); 418#endif 419 td->td_retval[0] = 0; 420 td->td_retval[1] = frame->fixreg[FIRSTARG + 1]; 421 422 STOPEVENT(p, S_SCE, narg); 423 424 error = (*callp->sy_call)(td, params); 425 switch (error) { 426 case 0: 427 frame->fixreg[FIRSTARG] = td->td_retval[0]; 428 frame->fixreg[FIRSTARG + 1] = td->td_retval[1]; 429 /* XXX: Magic number */ 430 frame->cr &= ~0x10000000; 431 break; 432 case ERESTART: 433 /* 434 * Set user's pc back to redo the system call. 435 */ 436 frame->srr0 -= 4; 437 break; 438 case EJUSTRETURN: 439 /* nothing to do */ 440 break; 441 default: 442bad: 443 if (p->p_sysent->sv_errsize) { 444 if (error >= p->p_sysent->sv_errsize) 445 error = -1; /* XXX */ 446 else 447 error = p->p_sysent->sv_errtbl[error]; 448 } 449 frame->fixreg[FIRSTARG] = error; 450 /* XXX: Magic number: Carry Flag Equivalent? */ 451 frame->cr |= 0x10000000; 452 break; 453 } 454 455 456#ifdef KTRACE 457 if (KTRPOINT(p, KTR_SYSRET)) 458 ktrsysret(p->p_tracep, code, error, td->td_retval[0]); 459#endif 460 461 if ((callp->sy_narg & SYF_MPSAFE) == 0) 462 mtx_unlock(&Giant); 463 464 /* 465 * Does the comment in the i386 code about errno apply here? 466 */ 467 STOPEVENT(p, S_SCX, code); 468 469#ifdef WITNESS 470 if (witness_list(td)) { 471 panic("system call %s returning with mutex(s) held\n", 472 syscallnames[code]); 473 } 474#endif 475 mtx_assert(&sched_lock, MA_NOTOWNED); 476 mtx_assert(&Giant, MA_NOTOWNED); 477} 478 479static int 480trap_pfault(struct trapframe *frame, int user) 481{ 482 vm_offset_t eva, va; 483 struct thread *td; 484 struct proc *p; 485 vm_map_t map; 486 vm_prot_t ftype; 487 int rv; 488 u_int user_sr; 489 490 td = curthread; 491 p = td->td_proc; 492 if (frame->exc == EXC_ISI) { 493 eva = frame->srr0; 494 ftype = VM_PROT_READ | VM_PROT_EXECUTE; 495 } else { 496 eva = frame->dar; 497 if (frame->dsisr & DSISR_STORE) 498 ftype = VM_PROT_READ | VM_PROT_WRITE; 499 else 500 ftype = VM_PROT_READ; 501 } 502 503 if (user) { 504 map = &p->p_vmspace->vm_map; 505 } else { 506 if ((eva >> ADDR_SR_SHFT) == USER_SR) { 507 if (p->p_vmspace == NULL) 508 return (SIGSEGV); 509 510 __asm ("mfsr %0, %1" 511 : "=r"(user_sr) 512 : "K"(USER_SR)); 513 eva &= ADDR_PIDX | ADDR_POFF; 514 eva |= user_sr << ADDR_SR_SHFT; 515 map = &p->p_vmspace->vm_map; 516 } else { 517 map = kernel_map; 518 } 519 } 520 va = trunc_page(eva); 521 522 mtx_lock(&Giant); 523 if (map != kernel_map) { 524 /* 525 * Keep swapout from messing with us during this 526 * critical time. 527 */ 528 PROC_LOCK(p); 529 ++p->p_lock; 530 PROC_UNLOCK(p); 531 532 /* Fault in the user page: */ 533 rv = vm_fault(map, va, ftype, 534 (ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY 535 : VM_FAULT_NORMAL); 536 537 PROC_LOCK(p); 538 --p->p_lock; 539 PROC_UNLOCK(p); 540 } else { 541 /* 542 * Don't have to worry about process locking or stacks in the 543 * kernel. 544 */ 545 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 546 } 547 mtx_unlock(&Giant); 548 549 if (rv == KERN_SUCCESS) 550 return (0); 551 552 if (!user && handle_onfault(frame)) 553 return (0); 554 555 return (SIGSEGV); 556} 557 558static __inline void 559setusr(u_int content) 560{ 561 __asm __volatile ("isync; mtsr %0,%1; isync" 562 :: "n"(USER_SR), "r"(content)); 563} 564 565int 566badaddr(void *addr, size_t size) 567{ 568 return (badaddr_read(addr, size, NULL)); 569} 570 571int 572badaddr_read(void *addr, size_t size, int *rptr) 573{ 574 struct thread *td; 575 faultbuf env; 576 int x; 577 578 /* Get rid of any stale machine checks that have been waiting. */ 579 __asm __volatile ("sync; isync"); 580 581 td = PCPU_GET(curthread); 582 583 if (setfault(env)) { 584 td->td_pcb->pcb_onfault = 0; 585 __asm __volatile ("sync"); 586 return 1; 587 } 588 589 __asm __volatile ("sync"); 590 591 switch (size) { 592 case 1: 593 x = *(volatile int8_t *)addr; 594 break; 595 case 2: 596 x = *(volatile int16_t *)addr; 597 break; 598 case 4: 599 x = *(volatile int32_t *)addr; 600 break; 601 default: 602 panic("badaddr: invalid size (%d)", size); 603 } 604 605 /* Make sure we took the machine check, if we caused one. */ 606 __asm __volatile ("sync; isync"); 607 608 td->td_pcb->pcb_onfault = 0; 609 __asm __volatile ("sync"); /* To be sure. */ 610 611 /* Use the value to avoid reorder. */ 612 if (rptr) 613 *rptr = x; 614 615 return (0); 616} 617 618/* 619 * For now, this only deals with the particular unaligned access case 620 * that gcc tends to generate. Eventually it should handle all of the 621 * possibilities that can happen on a 32-bit PowerPC in big-endian mode. 622 */ 623 624static int 625fix_unaligned(struct thread *td, struct trapframe *frame) 626{ 627 struct thread *fputhread; 628 int indicator, reg; 629 double *fpr; 630 631 indicator = EXC_ALI_OPCODE_INDICATOR(frame->dsisr); 632 633 switch (indicator) { 634 case EXC_ALI_LFD: 635 case EXC_ALI_STFD: 636 reg = EXC_ALI_RST(frame->dsisr); 637 fpr = &td->td_pcb->pcb_fpu.fpr[reg]; 638 fputhread = PCPU_GET(fputhread); 639 640 /* Juggle the FPU to ensure that we've initialized 641 * the FPRs, and that their current state is in 642 * the PCB. 643 */ 644 if (fputhread != td) { 645 if (fputhread) 646 save_fpu(fputhread); 647 enable_fpu(td); 648 } 649 save_fpu(td); 650 651 if (indicator == EXC_ALI_LFD) { 652 if (copyin((void *)frame->dar, fpr, 653 sizeof(double)) != 0) 654 return -1; 655 enable_fpu(td); 656 } else { 657 if (copyout(fpr, (void *)frame->dar, 658 sizeof(double)) != 0) 659 return -1; 660 } 661 return 0; 662 break; 663 } 664 665 return -1; 666} 667