trap.c revision 268600
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 268600 2014-07-14 04:38:17Z markj $"); 36 37#include <sys/param.h> 38#include <sys/kdb.h> 39#include <sys/proc.h> 40#include <sys/ktr.h> 41#include <sys/lock.h> 42#include <sys/mutex.h> 43#include <sys/pioctl.h> 44#include <sys/ptrace.h> 45#include <sys/reboot.h> 46#include <sys/syscall.h> 47#include <sys/sysent.h> 48#include <sys/systm.h> 49#include <sys/uio.h> 50#include <sys/signalvar.h> 51#include <sys/vmmeter.h> 52 53#include <security/audit/audit.h> 54 55#include <vm/vm.h> 56#include <vm/pmap.h> 57#include <vm/vm_extern.h> 58#include <vm/vm_param.h> 59#include <vm/vm_kern.h> 60#include <vm/vm_map.h> 61#include <vm/vm_page.h> 62 63#include <machine/_inttypes.h> 64#include <machine/altivec.h> 65#include <machine/cpu.h> 66#include <machine/db_machdep.h> 67#include <machine/fpu.h> 68#include <machine/frame.h> 69#include <machine/pcb.h> 70#include <machine/pmap.h> 71#include <machine/psl.h> 72#include <machine/trap.h> 73#include <machine/spr.h> 74#include <machine/sr.h> 75 76static void trap_fatal(struct trapframe *frame); 77static void printtrap(u_int vector, struct trapframe *frame, int isfatal, 78 int user); 79static int trap_pfault(struct trapframe *frame, int user); 80static int fix_unaligned(struct thread *td, struct trapframe *frame); 81static int handle_onfault(struct trapframe *frame); 82static void syscall(struct trapframe *frame); 83 84#ifdef __powerpc64__ 85 void handle_kernel_slb_spill(int, register_t, register_t); 86static int handle_user_slb_spill(pmap_t pm, vm_offset_t addr); 87extern int n_slbs; 88#endif 89 90struct powerpc_exception { 91 u_int vector; 92 char *name; 93}; 94 95#ifdef KDTRACE_HOOKS 96#include <sys/dtrace_bsd.h> 97 98int (*dtrace_invop_jump_addr)(struct trapframe *); 99#endif 100 101static struct powerpc_exception powerpc_exceptions[] = { 102 { 0x0100, "system reset" }, 103 { 0x0200, "machine check" }, 104 { 0x0300, "data storage interrupt" }, 105 { 0x0380, "data segment exception" }, 106 { 0x0400, "instruction storage interrupt" }, 107 { 0x0480, "instruction segment exception" }, 108 { 0x0500, "external interrupt" }, 109 { 0x0600, "alignment" }, 110 { 0x0700, "program" }, 111 { 0x0800, "floating-point unavailable" }, 112 { 0x0900, "decrementer" }, 113 { 0x0c00, "system call" }, 114 { 0x0d00, "trace" }, 115 { 0x0e00, "floating-point assist" }, 116 { 0x0f00, "performance monitoring" }, 117 { 0x0f20, "altivec unavailable" }, 118 { 0x1000, "instruction tlb miss" }, 119 { 0x1100, "data load tlb miss" }, 120 { 0x1200, "data store tlb miss" }, 121 { 0x1300, "instruction breakpoint" }, 122 { 0x1400, "system management" }, 123 { 0x1600, "altivec assist" }, 124 { 0x1700, "thermal management" }, 125 { 0x2000, "run mode/trace" }, 126 { 0x3000, NULL } 127}; 128 129static const char * 130trapname(u_int vector) 131{ 132 struct powerpc_exception *pe; 133 134 for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) { 135 if (pe->vector == vector) 136 return (pe->name); 137 } 138 139 return ("unknown"); 140} 141 142void 143trap(struct trapframe *frame) 144{ 145 struct thread *td; 146 struct proc *p; 147#ifdef KDTRACE_HOOKS 148 uint32_t inst; 149#endif 150 int sig, type, user; 151 u_int ucode; 152 ksiginfo_t ksi; 153 154 PCPU_INC(cnt.v_trap); 155 156 td = curthread; 157 p = td->td_proc; 158 159 type = ucode = frame->exc; 160 sig = 0; 161 user = frame->srr1 & PSL_PR; 162 163 CTR3(KTR_TRAP, "trap: %s type=%s (%s)", td->td_name, 164 trapname(type), user ? "user" : "kernel"); 165 166#ifdef KDTRACE_HOOKS 167 /* 168 * A trap can occur while DTrace executes a probe. Before 169 * executing the probe, DTrace blocks re-scheduling and sets 170 * a flag in its per-cpu flags to indicate that it doesn't 171 * want to fault. On returning from the probe, the no-fault 172 * flag is cleared and finally re-scheduling is enabled. 173 * 174 * If the DTrace kernel module has registered a trap handler, 175 * call it and if it returns non-zero, assume that it has 176 * handled the trap and modified the trap frame so that this 177 * function can return normally. 178 */ 179 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame)) 180 return; 181#endif 182 183 if (user) { 184 td->td_pticks = 0; 185 td->td_frame = frame; 186 if (td->td_ucred != p->p_ucred) 187 cred_update_thread(td); 188 189 /* User Mode Traps */ 190 switch (type) { 191 case EXC_RUNMODETRC: 192 case EXC_TRC: 193 frame->srr1 &= ~PSL_SE; 194 sig = SIGTRAP; 195 break; 196 197#ifdef __powerpc64__ 198 case EXC_ISE: 199 case EXC_DSE: 200 if (handle_user_slb_spill(&p->p_vmspace->vm_pmap, 201 (type == EXC_ISE) ? frame->srr0 : 202 frame->cpu.aim.dar) != 0) 203 sig = SIGSEGV; 204 break; 205#endif 206 case EXC_DSI: 207 case EXC_ISI: 208 sig = trap_pfault(frame, 1); 209 break; 210 211 case EXC_SC: 212 syscall(frame); 213 break; 214 215 case EXC_FPU: 216 KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU, 217 ("FPU already enabled for thread")); 218 enable_fpu(td); 219 break; 220 221 case EXC_VEC: 222 KASSERT((td->td_pcb->pcb_flags & PCB_VEC) != PCB_VEC, 223 ("Altivec already enabled for thread")); 224 enable_vec(td); 225 break; 226 227 case EXC_VECAST_G4: 228 case EXC_VECAST_G5: 229 /* 230 * We get a VPU assist exception for IEEE mode 231 * vector operations on denormalized floats. 232 * Emulating this is a giant pain, so for now, 233 * just switch off IEEE mode and treat them as 234 * zero. 235 */ 236 237 save_vec(td); 238 td->td_pcb->pcb_vec.vscr |= ALTIVEC_VSCR_NJ; 239 enable_vec(td); 240 break; 241 242 case EXC_ALI: 243 if (fix_unaligned(td, frame) != 0) 244 sig = SIGBUS; 245 else 246 frame->srr0 += 4; 247 break; 248 249 case EXC_PGM: 250 /* Identify the trap reason */ 251 if (frame->srr1 & EXC_PGM_TRAP) { 252#ifdef KDTRACE_HOOKS 253 inst = fuword32((const void *)frame->srr0); 254 if (inst == 0x0FFFDDDD && dtrace_pid_probe_ptr != NULL) { 255 struct reg regs; 256 fill_regs(td, ®s); 257 (*dtrace_pid_probe_ptr)(®s); 258 break; 259 } 260#endif 261 sig = SIGTRAP; 262 } else { 263 sig = ppc_instr_emulate(frame, td->td_pcb); 264 } 265 break; 266 267 default: 268 trap_fatal(frame); 269 } 270 } else { 271 /* Kernel Mode Traps */ 272 273 KASSERT(cold || td->td_ucred != NULL, 274 ("kernel trap doesn't have ucred")); 275 switch (type) { 276#ifdef KDTRACE_HOOKS 277 case EXC_PGM: 278 if (frame->srr1 & EXC_PGM_TRAP) { 279 if (*(uint32_t *)frame->srr0 == 0x7c810808) { 280 if (dtrace_invop_jump_addr != NULL) { 281 dtrace_invop_jump_addr(frame); 282 return; 283 } 284 } 285 } 286 break; 287#endif 288#ifdef __powerpc64__ 289 case EXC_DSE: 290 if ((frame->cpu.aim.dar & SEGMENT_MASK) == USER_ADDR) { 291 __asm __volatile ("slbmte %0, %1" :: 292 "r"(td->td_pcb->pcb_cpu.aim.usr_vsid), 293 "r"(USER_SLB_SLBE)); 294 return; 295 } 296 break; 297#endif 298 case EXC_DSI: 299 if (trap_pfault(frame, 0) == 0) 300 return; 301 break; 302 case EXC_MCHK: 303 if (handle_onfault(frame)) 304 return; 305 break; 306 default: 307 break; 308 } 309 trap_fatal(frame); 310 } 311 312 if (sig != 0) { 313 if (p->p_sysent->sv_transtrap != NULL) 314 sig = (p->p_sysent->sv_transtrap)(sig, type); 315 ksiginfo_init_trap(&ksi); 316 ksi.ksi_signo = sig; 317 ksi.ksi_code = (int) ucode; /* XXX, not POSIX */ 318 /* ksi.ksi_addr = ? */ 319 ksi.ksi_trapno = type; 320 trapsignal(td, &ksi); 321 } 322 323 userret(td, frame); 324} 325 326static void 327trap_fatal(struct trapframe *frame) 328{ 329 330 printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR)); 331#ifdef KDB 332 if ((debugger_on_panic || kdb_active) && 333 kdb_trap(frame->exc, 0, frame)) 334 return; 335#endif 336 panic("%s trap", trapname(frame->exc)); 337} 338 339static void 340printtrap(u_int vector, struct trapframe *frame, int isfatal, int user) 341{ 342 343 printf("\n"); 344 printf("%s %s trap:\n", isfatal ? "fatal" : "handled", 345 user ? "user" : "kernel"); 346 printf("\n"); 347 printf(" exception = 0x%x (%s)\n", vector, trapname(vector)); 348 switch (vector) { 349 case EXC_DSE: 350 case EXC_DSI: 351 printf(" virtual address = 0x%" PRIxPTR "\n", 352 frame->cpu.aim.dar); 353 printf(" dsisr = 0x%" PRIxPTR "\n", 354 frame->cpu.aim.dsisr); 355 break; 356 case EXC_ISE: 357 case EXC_ISI: 358 printf(" virtual address = 0x%" PRIxPTR "\n", frame->srr0); 359 break; 360 } 361 printf(" srr0 = 0x%" PRIxPTR "\n", frame->srr0); 362 printf(" srr1 = 0x%" PRIxPTR "\n", frame->srr1); 363 printf(" lr = 0x%" PRIxPTR "\n", frame->lr); 364 printf(" curthread = %p\n", curthread); 365 if (curthread != NULL) 366 printf(" pid = %d, comm = %s\n", 367 curthread->td_proc->p_pid, curthread->td_name); 368 printf("\n"); 369} 370 371/* 372 * Handles a fatal fault when we have onfault state to recover. Returns 373 * non-zero if there was onfault recovery state available. 374 */ 375static int 376handle_onfault(struct trapframe *frame) 377{ 378 struct thread *td; 379 faultbuf *fb; 380 381 td = curthread; 382 fb = td->td_pcb->pcb_onfault; 383 if (fb != NULL) { 384 frame->srr0 = (*fb)[0]; 385 frame->fixreg[1] = (*fb)[1]; 386 frame->fixreg[2] = (*fb)[2]; 387 frame->fixreg[3] = 1; 388 frame->cr = (*fb)[3]; 389 bcopy(&(*fb)[4], &frame->fixreg[13], 390 19 * sizeof(register_t)); 391 return (1); 392 } 393 return (0); 394} 395 396int 397cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa) 398{ 399 struct proc *p; 400 struct trapframe *frame; 401 caddr_t params; 402 size_t argsz; 403 int error, n, i; 404 405 p = td->td_proc; 406 frame = td->td_frame; 407 408 sa->code = frame->fixreg[0]; 409 params = (caddr_t)(frame->fixreg + FIRSTARG); 410 n = NARGREG; 411 412 if (sa->code == SYS_syscall) { 413 /* 414 * code is first argument, 415 * followed by actual args. 416 */ 417 sa->code = *(register_t *) params; 418 params += sizeof(register_t); 419 n -= 1; 420 } else if (sa->code == SYS___syscall) { 421 /* 422 * Like syscall, but code is a quad, 423 * so as to maintain quad alignment 424 * for the rest of the args. 425 */ 426 if (SV_PROC_FLAG(p, SV_ILP32)) { 427 params += sizeof(register_t); 428 sa->code = *(register_t *) params; 429 params += sizeof(register_t); 430 n -= 2; 431 } else { 432 sa->code = *(register_t *) params; 433 params += sizeof(register_t); 434 n -= 1; 435 } 436 } 437 438 if (p->p_sysent->sv_mask) 439 sa->code &= p->p_sysent->sv_mask; 440 if (sa->code >= p->p_sysent->sv_size) 441 sa->callp = &p->p_sysent->sv_table[0]; 442 else 443 sa->callp = &p->p_sysent->sv_table[sa->code]; 444 445 sa->narg = sa->callp->sy_narg; 446 447 if (SV_PROC_FLAG(p, SV_ILP32)) { 448 argsz = sizeof(uint32_t); 449 450 for (i = 0; i < n; i++) 451 sa->args[i] = ((u_register_t *)(params))[i] & 452 0xffffffff; 453 } else { 454 argsz = sizeof(uint64_t); 455 456 for (i = 0; i < n; i++) 457 sa->args[i] = ((u_register_t *)(params))[i]; 458 } 459 460 if (sa->narg > n) 461 error = copyin(MOREARGS(frame->fixreg[1]), sa->args + n, 462 (sa->narg - n) * argsz); 463 else 464 error = 0; 465 466#ifdef __powerpc64__ 467 if (SV_PROC_FLAG(p, SV_ILP32) && sa->narg > n) { 468 /* Expand the size of arguments copied from the stack */ 469 470 for (i = sa->narg; i >= n; i--) 471 sa->args[i] = ((uint32_t *)(&sa->args[n]))[i-n]; 472 } 473#endif 474 475 if (error == 0) { 476 td->td_retval[0] = 0; 477 td->td_retval[1] = frame->fixreg[FIRSTARG + 1]; 478 } 479 return (error); 480} 481 482#include "../../kern/subr_syscall.c" 483 484void 485syscall(struct trapframe *frame) 486{ 487 struct thread *td; 488 struct syscall_args sa; 489 int error; 490 491 td = curthread; 492 td->td_frame = frame; 493 494#ifdef __powerpc64__ 495 /* 496 * Speculatively restore last user SLB segment, which we know is 497 * invalid already, since we are likely to do copyin()/copyout(). 498 */ 499 __asm __volatile ("slbmte %0, %1; isync" :: 500 "r"(td->td_pcb->pcb_cpu.aim.usr_vsid), "r"(USER_SLB_SLBE)); 501#endif 502 503 error = syscallenter(td, &sa); 504 syscallret(td, error, &sa); 505} 506 507#ifdef __powerpc64__ 508/* Handle kernel SLB faults -- runs in real mode, all seat belts off */ 509void 510handle_kernel_slb_spill(int type, register_t dar, register_t srr0) 511{ 512 struct slb *slbcache; 513 uint64_t slbe, slbv; 514 uint64_t esid, addr; 515 int i; 516 517 addr = (type == EXC_ISE) ? srr0 : dar; 518 slbcache = PCPU_GET(slb); 519 esid = (uintptr_t)addr >> ADDR_SR_SHFT; 520 slbe = (esid << SLBE_ESID_SHIFT) | SLBE_VALID; 521 522 /* See if the hardware flushed this somehow (can happen in LPARs) */ 523 for (i = 0; i < n_slbs; i++) 524 if (slbcache[i].slbe == (slbe | (uint64_t)i)) 525 return; 526 527 /* Not in the map, needs to actually be added */ 528 slbv = kernel_va_to_slbv(addr); 529 if (slbcache[USER_SLB_SLOT].slbe == 0) { 530 for (i = 0; i < n_slbs; i++) { 531 if (i == USER_SLB_SLOT) 532 continue; 533 if (!(slbcache[i].slbe & SLBE_VALID)) 534 goto fillkernslb; 535 } 536 537 if (i == n_slbs) 538 slbcache[USER_SLB_SLOT].slbe = 1; 539 } 540 541 /* Sacrifice a random SLB entry that is not the user entry */ 542 i = mftb() % n_slbs; 543 if (i == USER_SLB_SLOT) 544 i = (i+1) % n_slbs; 545 546fillkernslb: 547 /* Write new entry */ 548 slbcache[i].slbv = slbv; 549 slbcache[i].slbe = slbe | (uint64_t)i; 550 551 /* Trap handler will restore from cache on exit */ 552} 553 554static int 555handle_user_slb_spill(pmap_t pm, vm_offset_t addr) 556{ 557 struct slb *user_entry; 558 uint64_t esid; 559 int i; 560 561 esid = (uintptr_t)addr >> ADDR_SR_SHFT; 562 563 PMAP_LOCK(pm); 564 user_entry = user_va_to_slb_entry(pm, addr); 565 566 if (user_entry == NULL) { 567 /* allocate_vsid auto-spills it */ 568 (void)allocate_user_vsid(pm, esid, 0); 569 } else { 570 /* 571 * Check that another CPU has not already mapped this. 572 * XXX: Per-thread SLB caches would be better. 573 */ 574 for (i = 0; i < pm->pm_slb_len; i++) 575 if (pm->pm_slb[i] == user_entry) 576 break; 577 578 if (i == pm->pm_slb_len) 579 slb_insert_user(pm, user_entry); 580 } 581 PMAP_UNLOCK(pm); 582 583 return (0); 584} 585#endif 586 587static int 588trap_pfault(struct trapframe *frame, int user) 589{ 590 vm_offset_t eva, va; 591 struct thread *td; 592 struct proc *p; 593 vm_map_t map; 594 vm_prot_t ftype; 595 int rv; 596 register_t user_sr; 597 598 td = curthread; 599 p = td->td_proc; 600 if (frame->exc == EXC_ISI) { 601 eva = frame->srr0; 602 ftype = VM_PROT_EXECUTE; 603 if (frame->srr1 & SRR1_ISI_PFAULT) 604 ftype |= VM_PROT_READ; 605 } else { 606 eva = frame->cpu.aim.dar; 607 if (frame->cpu.aim.dsisr & DSISR_STORE) 608 ftype = VM_PROT_WRITE; 609 else 610 ftype = VM_PROT_READ; 611 } 612 613 if (user) { 614 map = &p->p_vmspace->vm_map; 615 } else { 616 if ((eva >> ADDR_SR_SHFT) == (USER_ADDR >> ADDR_SR_SHFT)) { 617 if (p->p_vmspace == NULL) 618 return (SIGSEGV); 619 620 map = &p->p_vmspace->vm_map; 621 622 user_sr = td->td_pcb->pcb_cpu.aim.usr_segm; 623 eva &= ADDR_PIDX | ADDR_POFF; 624 eva |= user_sr << ADDR_SR_SHFT; 625 } else { 626 map = kernel_map; 627 } 628 } 629 va = trunc_page(eva); 630 631 if (map != kernel_map) { 632 /* 633 * Keep swapout from messing with us during this 634 * critical time. 635 */ 636 PROC_LOCK(p); 637 ++p->p_lock; 638 PROC_UNLOCK(p); 639 640 /* Fault in the user page: */ 641 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 642 643 PROC_LOCK(p); 644 --p->p_lock; 645 PROC_UNLOCK(p); 646 /* 647 * XXXDTRACE: add dtrace_doubletrap_func here? 648 */ 649 } else { 650 /* 651 * Don't have to worry about process locking or stacks in the 652 * kernel. 653 */ 654 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 655 } 656 657 if (rv == KERN_SUCCESS) 658 return (0); 659 660 if (!user && handle_onfault(frame)) 661 return (0); 662 663 return (SIGSEGV); 664} 665 666/* 667 * For now, this only deals with the particular unaligned access case 668 * that gcc tends to generate. Eventually it should handle all of the 669 * possibilities that can happen on a 32-bit PowerPC in big-endian mode. 670 */ 671 672static int 673fix_unaligned(struct thread *td, struct trapframe *frame) 674{ 675 struct thread *fputhread; 676 int indicator, reg; 677 double *fpr; 678 679 indicator = EXC_ALI_OPCODE_INDICATOR(frame->cpu.aim.dsisr); 680 681 switch (indicator) { 682 case EXC_ALI_LFD: 683 case EXC_ALI_STFD: 684 reg = EXC_ALI_RST(frame->cpu.aim.dsisr); 685 fpr = &td->td_pcb->pcb_fpu.fpr[reg]; 686 fputhread = PCPU_GET(fputhread); 687 688 /* Juggle the FPU to ensure that we've initialized 689 * the FPRs, and that their current state is in 690 * the PCB. 691 */ 692 if (fputhread != td) { 693 if (fputhread) 694 save_fpu(fputhread); 695 enable_fpu(td); 696 } 697 save_fpu(td); 698 699 if (indicator == EXC_ALI_LFD) { 700 if (copyin((void *)frame->cpu.aim.dar, fpr, 701 sizeof(double)) != 0) 702 return -1; 703 enable_fpu(td); 704 } else { 705 if (copyout(fpr, (void *)frame->cpu.aim.dar, 706 sizeof(double)) != 0) 707 return -1; 708 } 709 return 0; 710 break; 711 } 712 713 return -1; 714} 715 716