trap.c revision 199868
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 199868 2009-11-27 20:24:11Z alc $"); 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/altivec.h> 69#include <machine/cpu.h> 70#include <machine/db_machdep.h> 71#include <machine/fpu.h> 72#include <machine/frame.h> 73#include <machine/pcb.h> 74#include <machine/pmap.h> 75#include <machine/psl.h> 76#include <machine/trap.h> 77#include <machine/spr.h> 78#include <machine/sr.h> 79 80static void trap_fatal(struct trapframe *frame); 81static void printtrap(u_int vector, struct trapframe *frame, int isfatal, 82 int user); 83static int trap_pfault(struct trapframe *frame, int user); 84static int fix_unaligned(struct thread *td, struct trapframe *frame); 85static int handle_onfault(struct trapframe *frame); 86static void syscall(struct trapframe *frame); 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 96struct powerpc_exception { 97 u_int vector; 98 char *name; 99}; 100 101static struct powerpc_exception powerpc_exceptions[] = { 102 { 0x0100, "system reset" }, 103 { 0x0200, "machine check" }, 104 { 0x0300, "data storage interrupt" }, 105 { 0x0400, "instruction storage interrupt" }, 106 { 0x0500, "external interrupt" }, 107 { 0x0600, "alignment" }, 108 { 0x0700, "program" }, 109 { 0x0800, "floating-point unavailable" }, 110 { 0x0900, "decrementer" }, 111 { 0x0c00, "system call" }, 112 { 0x0d00, "trace" }, 113 { 0x0e00, "floating-point assist" }, 114 { 0x0f00, "performance monitoring" }, 115 { 0x0f20, "altivec unavailable" }, 116 { 0x1000, "instruction tlb miss" }, 117 { 0x1100, "data load tlb miss" }, 118 { 0x1200, "data store tlb miss" }, 119 { 0x1300, "instruction breakpoint" }, 120 { 0x1400, "system management" }, 121 { 0x1600, "altivec assist" }, 122 { 0x1700, "thermal management" }, 123 { 0x2000, "run mode/trace" }, 124 { 0x3000, NULL } 125}; 126 127static const char * 128trapname(u_int vector) 129{ 130 struct powerpc_exception *pe; 131 132 for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) { 133 if (pe->vector == vector) 134 return (pe->name); 135 } 136 137 return ("unknown"); 138} 139 140void 141trap(struct trapframe *frame) 142{ 143 struct thread *td; 144 struct proc *p; 145 int sig, type, user; 146 u_int ucode; 147 ksiginfo_t ksi; 148 149 PCPU_INC(cnt.v_trap); 150 151 td = PCPU_GET(curthread); 152 p = td->td_proc; 153 154 type = ucode = frame->exc; 155 sig = 0; 156 user = frame->srr1 & PSL_PR; 157 158 CTR3(KTR_TRAP, "trap: %s type=%s (%s)", td->td_name, 159 trapname(type), user ? "user" : "kernel"); 160 161 if (user) { 162 td->td_pticks = 0; 163 td->td_frame = frame; 164 if (td->td_ucred != p->p_ucred) 165 cred_update_thread(td); 166 167 /* User Mode Traps */ 168 switch (type) { 169 case EXC_RUNMODETRC: 170 case EXC_TRC: 171 frame->srr1 &= ~PSL_SE; 172 sig = SIGTRAP; 173 break; 174 175 case EXC_DSI: 176 case EXC_ISI: 177 sig = trap_pfault(frame, 1); 178 break; 179 180 case EXC_SC: 181 syscall(frame); 182 break; 183 184 case EXC_FPU: 185 KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU, 186 ("FPU already enabled for thread")); 187 enable_fpu(td); 188 break; 189 190 case EXC_VEC: 191 KASSERT((td->td_pcb->pcb_flags & PCB_VEC) != PCB_VEC, 192 ("Altivec already enabled for thread")); 193 enable_vec(td); 194 break; 195 196 case EXC_VECAST: 197 printf("Vector assist exception!\n"); 198 sig = SIGILL; 199 break; 200 201 case EXC_ALI: 202 if (fix_unaligned(td, frame) != 0) 203 sig = SIGBUS; 204 else 205 frame->srr0 += 4; 206 break; 207 208 case EXC_PGM: 209 /* Identify the trap reason */ 210 if (frame->srr1 & EXC_PGM_TRAP) 211 sig = SIGTRAP; 212 else 213 sig = SIGILL; 214 break; 215 216 default: 217 trap_fatal(frame); 218 } 219 } else { 220 /* Kernel Mode Traps */ 221 222 KASSERT(cold || td->td_ucred != NULL, 223 ("kernel trap doesn't have ucred")); 224 switch (type) { 225 case EXC_DSI: 226 if (trap_pfault(frame, 0) == 0) 227 return; 228 break; 229 case EXC_MCHK: 230 if (handle_onfault(frame)) 231 return; 232 break; 233 default: 234 break; 235 } 236 trap_fatal(frame); 237 } 238 239 if (sig != 0) { 240 if (p->p_sysent->sv_transtrap != NULL) 241 sig = (p->p_sysent->sv_transtrap)(sig, type); 242 ksiginfo_init_trap(&ksi); 243 ksi.ksi_signo = sig; 244 ksi.ksi_code = (int) ucode; /* XXX, not POSIX */ 245 /* ksi.ksi_addr = ? */ 246 ksi.ksi_trapno = type; 247 trapsignal(td, &ksi); 248 } 249 250 userret(td, frame); 251 mtx_assert(&Giant, MA_NOTOWNED); 252} 253 254static void 255trap_fatal(struct trapframe *frame) 256{ 257 258 printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR)); 259#ifdef KDB 260 if ((debugger_on_panic || kdb_active) && 261 kdb_trap(frame->exc, 0, frame)) 262 return; 263#endif 264 panic("%s trap", trapname(frame->exc)); 265} 266 267static void 268printtrap(u_int vector, struct trapframe *frame, int isfatal, int user) 269{ 270 271 printf("\n"); 272 printf("%s %s trap:\n", isfatal ? "fatal" : "handled", 273 user ? "user" : "kernel"); 274 printf("\n"); 275 printf(" exception = 0x%x (%s)\n", vector >> 8, 276 trapname(vector)); 277 switch (vector) { 278 case EXC_DSI: 279 printf(" virtual address = 0x%x\n", frame->cpu.aim.dar); 280 break; 281 case EXC_ISI: 282 printf(" virtual address = 0x%x\n", frame->srr0); 283 break; 284 } 285 printf(" srr0 = 0x%x\n", frame->srr0); 286 printf(" srr1 = 0x%x\n", frame->srr1); 287 printf(" lr = 0x%x\n", frame->lr); 288 printf(" curthread = %p\n", curthread); 289 if (curthread != NULL) 290 printf(" pid = %d, comm = %s\n", 291 curthread->td_proc->p_pid, curthread->td_name); 292 printf("\n"); 293} 294 295/* 296 * Handles a fatal fault when we have onfault state to recover. Returns 297 * non-zero if there was onfault recovery state available. 298 */ 299static int 300handle_onfault(struct trapframe *frame) 301{ 302 struct thread *td; 303 faultbuf *fb; 304 305 td = curthread; 306 fb = td->td_pcb->pcb_onfault; 307 if (fb != NULL) { 308 frame->srr0 = (*fb)[0]; 309 frame->fixreg[1] = (*fb)[1]; 310 frame->fixreg[2] = (*fb)[2]; 311 frame->fixreg[3] = 1; 312 frame->cr = (*fb)[3]; 313 bcopy(&(*fb)[4], &frame->fixreg[13], 314 19 * sizeof(register_t)); 315 return (1); 316 } 317 return (0); 318} 319 320void 321syscall(struct trapframe *frame) 322{ 323 caddr_t params; 324 struct sysent *callp; 325 struct thread *td; 326 struct proc *p; 327 int error, n; 328 size_t narg; 329 register_t args[10]; 330 u_int code; 331 332 td = PCPU_GET(curthread); 333 p = td->td_proc; 334 335 PCPU_INC(cnt.v_syscall); 336 337 code = frame->fixreg[0]; 338 params = (caddr_t)(frame->fixreg + FIRSTARG); 339 n = NARGREG; 340 341 if (p->p_sysent->sv_prepsyscall) { 342 /* 343 * The prep code is MP aware. 344 */ 345 (*p->p_sysent->sv_prepsyscall)(frame, args, &code, ¶ms); 346 } else if (code == SYS_syscall) { 347 /* 348 * code is first argument, 349 * followed by actual args. 350 */ 351 code = *(u_int *) params; 352 params += sizeof(register_t); 353 n -= 1; 354 } else if (code == SYS___syscall) { 355 /* 356 * Like syscall, but code is a quad, 357 * so as to maintain quad alignment 358 * for the rest of the args. 359 */ 360 params += sizeof(register_t); 361 code = *(u_int *) params; 362 params += sizeof(register_t); 363 n -= 2; 364 } 365 366 if (p->p_sysent->sv_mask) 367 code &= p->p_sysent->sv_mask; 368 369 if (code >= p->p_sysent->sv_size) 370 callp = &p->p_sysent->sv_table[0]; 371 else 372 callp = &p->p_sysent->sv_table[code]; 373 374 narg = callp->sy_narg; 375 376 if (narg > n) { 377 bcopy(params, args, n * sizeof(register_t)); 378 error = copyin(MOREARGS(frame->fixreg[1]), args + n, 379 (narg - n) * sizeof(register_t)); 380 params = (caddr_t)args; 381 } else 382 error = 0; 383 384 CTR5(KTR_SYSC, "syscall: p=%s %s(%x %x %x)", td->td_name, 385 syscallnames[code], 386 frame->fixreg[FIRSTARG], 387 frame->fixreg[FIRSTARG+1], 388 frame->fixreg[FIRSTARG+2]); 389 390#ifdef KTRACE 391 if (KTRPOINT(td, KTR_SYSCALL)) 392 ktrsyscall(code, narg, (register_t *)params); 393#endif 394 395 td->td_syscalls++; 396 397 if (error == 0) { 398 td->td_retval[0] = 0; 399 td->td_retval[1] = frame->fixreg[FIRSTARG + 1]; 400 401 STOPEVENT(p, S_SCE, narg); 402 403 PTRACESTOP_SC(p, td, S_PT_SCE); 404 405 AUDIT_SYSCALL_ENTER(code, td); 406 error = (*callp->sy_call)(td, params); 407 AUDIT_SYSCALL_EXIT(error, td); 408 409 CTR3(KTR_SYSC, "syscall: p=%s %s ret=%x", td->td_name, 410 syscallnames[code], td->td_retval[0]); 411 } 412 413 cpu_set_syscall_retval(td, error); 414 415 /* 416 * Check for misbehavior. 417 */ 418 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning", 419 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???"); 420 KASSERT(td->td_critnest == 0, 421 ("System call %s returning in a critical section", 422 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???")); 423 KASSERT(td->td_locks == 0, 424 ("System call %s returning with %d locks held", 425 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???", 426 td->td_locks)); 427 428#ifdef KTRACE 429 if (KTRPOINT(td, KTR_SYSRET)) 430 ktrsysret(code, error, td->td_retval[0]); 431#endif 432 433 /* 434 * Does the comment in the i386 code about errno apply here? 435 */ 436 STOPEVENT(p, S_SCX, code); 437 438 PTRACESTOP_SC(p, td, S_PT_SCX); 439} 440 441static int 442trap_pfault(struct trapframe *frame, int user) 443{ 444 vm_offset_t eva, va; 445 struct thread *td; 446 struct proc *p; 447 vm_map_t map; 448 vm_prot_t ftype; 449 int rv; 450 u_int user_sr; 451 452 td = curthread; 453 p = td->td_proc; 454 if (frame->exc == EXC_ISI) { 455 eva = frame->srr0; 456 ftype = VM_PROT_READ | VM_PROT_EXECUTE; 457 } else { 458 eva = frame->cpu.aim.dar; 459 if (frame->cpu.aim.dsisr & DSISR_STORE) 460 ftype = VM_PROT_WRITE; 461 else 462 ftype = VM_PROT_READ; 463 } 464 465 if (user) { 466 map = &p->p_vmspace->vm_map; 467 } else { 468 if ((eva >> ADDR_SR_SHFT) == USER_SR) { 469 if (p->p_vmspace == NULL) 470 return (SIGSEGV); 471 472 __asm ("mfsr %0, %1" 473 : "=r"(user_sr) 474 : "K"(USER_SR)); 475 eva &= ADDR_PIDX | ADDR_POFF; 476 eva |= user_sr << ADDR_SR_SHFT; 477 map = &p->p_vmspace->vm_map; 478 } else { 479 map = kernel_map; 480 } 481 } 482 va = trunc_page(eva); 483 484 if (map != kernel_map) { 485 /* 486 * Keep swapout from messing with us during this 487 * critical time. 488 */ 489 PROC_LOCK(p); 490 ++p->p_lock; 491 PROC_UNLOCK(p); 492 493 /* Fault in the user page: */ 494 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 495 496 PROC_LOCK(p); 497 --p->p_lock; 498 PROC_UNLOCK(p); 499 } else { 500 /* 501 * Don't have to worry about process locking or stacks in the 502 * kernel. 503 */ 504 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 505 } 506 507 if (rv == KERN_SUCCESS) 508 return (0); 509 510 if (!user && handle_onfault(frame)) 511 return (0); 512 513 return (SIGSEGV); 514} 515 516int 517badaddr(void *addr, size_t size) 518{ 519 return (badaddr_read(addr, size, NULL)); 520} 521 522int 523badaddr_read(void *addr, size_t size, int *rptr) 524{ 525 struct thread *td; 526 faultbuf env; 527 int x; 528 529 /* Get rid of any stale machine checks that have been waiting. */ 530 __asm __volatile ("sync; isync"); 531 532 td = PCPU_GET(curthread); 533 534 if (setfault(env)) { 535 td->td_pcb->pcb_onfault = 0; 536 __asm __volatile ("sync"); 537 return 1; 538 } 539 540 __asm __volatile ("sync"); 541 542 switch (size) { 543 case 1: 544 x = *(volatile int8_t *)addr; 545 break; 546 case 2: 547 x = *(volatile int16_t *)addr; 548 break; 549 case 4: 550 x = *(volatile int32_t *)addr; 551 break; 552 default: 553 panic("badaddr: invalid size (%d)", size); 554 } 555 556 /* Make sure we took the machine check, if we caused one. */ 557 __asm __volatile ("sync; isync"); 558 559 td->td_pcb->pcb_onfault = 0; 560 __asm __volatile ("sync"); /* To be sure. */ 561 562 /* Use the value to avoid reorder. */ 563 if (rptr) 564 *rptr = x; 565 566 return (0); 567} 568 569/* 570 * For now, this only deals with the particular unaligned access case 571 * that gcc tends to generate. Eventually it should handle all of the 572 * possibilities that can happen on a 32-bit PowerPC in big-endian mode. 573 */ 574 575static int 576fix_unaligned(struct thread *td, struct trapframe *frame) 577{ 578 struct thread *fputhread; 579 int indicator, reg; 580 double *fpr; 581 582 indicator = EXC_ALI_OPCODE_INDICATOR(frame->cpu.aim.dsisr); 583 584 switch (indicator) { 585 case EXC_ALI_LFD: 586 case EXC_ALI_STFD: 587 reg = EXC_ALI_RST(frame->cpu.aim.dsisr); 588 fpr = &td->td_pcb->pcb_fpu.fpr[reg]; 589 fputhread = PCPU_GET(fputhread); 590 591 /* Juggle the FPU to ensure that we've initialized 592 * the FPRs, and that their current state is in 593 * the PCB. 594 */ 595 if (fputhread != td) { 596 if (fputhread) 597 save_fpu(fputhread); 598 enable_fpu(td); 599 } 600 save_fpu(td); 601 602 if (indicator == EXC_ALI_LFD) { 603 if (copyin((void *)frame->cpu.aim.dar, fpr, 604 sizeof(double)) != 0) 605 return -1; 606 enable_fpu(td); 607 } else { 608 if (copyout(fpr, (void *)frame->cpu.aim.dar, 609 sizeof(double)) != 0) 610 return -1; 611 } 612 return 0; 613 break; 614 } 615 616 return -1; 617} 618