1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved. 24 */ 25 26 /* Copyright (c) 1990, 1991 UNIX System Laboratories, Inc. */ 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T */ 28 /* All Rights Reserved */ 29 /* */ 30 /* Copyright (c) 1987, 1988 Microsoft Corporation */ 31 /* All Rights Reserved */ 32 /* */ 33 34 /* 35 * Copyright 2012 Joyent, Inc. All rights reserved. 36 */ 37 38 #include <sys/types.h> 39 #include <sys/sysmacros.h> 40 #include <sys/param.h> 41 #include <sys/signal.h> 42 #include <sys/systm.h> 43 #include <sys/user.h> 44 #include <sys/proc.h> 45 #include <sys/disp.h> 46 #include <sys/class.h> 47 #include <sys/core.h> 48 #include <sys/syscall.h> 49 #include <sys/cpuvar.h> 50 #include <sys/vm.h> 51 #include <sys/sysinfo.h> 52 #include <sys/fault.h> 53 #include <sys/stack.h> 54 #include <sys/psw.h> 55 #include <sys/regset.h> 56 #include <sys/fp.h> 57 #include <sys/trap.h> 58 #include <sys/kmem.h> 59 #include <sys/vtrace.h> 60 #include <sys/cmn_err.h> 61 #include <sys/prsystm.h> 62 #include <sys/mutex_impl.h> 63 #include <sys/machsystm.h> 64 #include <sys/archsystm.h> 65 #include <sys/sdt.h> 66 #include <sys/avintr.h> 67 #include <sys/kobj.h> 68 69 #include <vm/hat.h> 70 71 #include <vm/seg_kmem.h> 72 #include <vm/as.h> 73 #include <vm/seg.h> 74 #include <vm/hat_pte.h> 75 #include <vm/hat_i86.h> 76 77 #include <sys/procfs.h> 78 79 #include <sys/reboot.h> 80 #include <sys/debug.h> 81 #include <sys/debugreg.h> 82 #include <sys/modctl.h> 83 #include <sys/aio_impl.h> 84 #include <sys/tnf.h> 85 #include <sys/tnf_probe.h> 86 #include <sys/cred.h> 87 #include <sys/mman.h> 88 #include <sys/x86_archext.h> 89 #include <sys/copyops.h> 90 #include <c2/audit.h> 91 #include <sys/ftrace.h> 92 #include <sys/panic.h> 93 #include <sys/traptrace.h> 94 #include <sys/ontrap.h> 95 #include <sys/cpc_impl.h> 96 #include <sys/bootconf.h> 97 #include <sys/bootinfo.h> 98 #include <sys/promif.h> 99 #include <sys/mach_mmu.h> 100 #if defined(__xpv) 101 #include <sys/hypervisor.h> 102 #endif 103 #include <sys/contract/process_impl.h> 104 105 #define USER 0x10000 /* user-mode flag added to trap type */ 106 107 static const char *trap_type_mnemonic[] = { 108 "de", "db", "2", "bp", 109 "of", "br", "ud", "nm", 110 "df", "9", "ts", "np", 111 "ss", "gp", "pf", "15", 112 "mf", "ac", "mc", "xf" 113 }; 114 115 static const char *trap_type[] = { 116 "Divide error", /* trap id 0 */ 117 "Debug", /* trap id 1 */ 118 "NMI interrupt", /* trap id 2 */ 119 "Breakpoint", /* trap id 3 */ 120 "Overflow", /* trap id 4 */ 121 "BOUND range exceeded", /* trap id 5 */ 122 "Invalid opcode", /* trap id 6 */ 123 "Device not available", /* trap id 7 */ 124 "Double fault", /* trap id 8 */ 125 "Coprocessor segment overrun", /* trap id 9 */ 126 "Invalid TSS", /* trap id 10 */ 127 "Segment not present", /* trap id 11 */ 128 "Stack segment fault", /* trap id 12 */ 129 "General protection", /* trap id 13 */ 130 "Page fault", /* trap id 14 */ 131 "Reserved", /* trap id 15 */ 132 "x87 floating point error", /* trap id 16 */ 133 "Alignment check", /* trap id 17 */ 134 "Machine check", /* trap id 18 */ 135 "SIMD floating point exception", /* trap id 19 */ 136 }; 137 138 #define TRAP_TYPES (sizeof (trap_type) / sizeof (trap_type[0])) 139 140 #define SLOW_SCALL_SIZE 2 141 #define FAST_SCALL_SIZE 2 142 143 int tudebug = 0; 144 int tudebugbpt = 0; 145 int tudebugfpe = 0; 146 int tudebugsse = 0; 147 148 #if defined(TRAPDEBUG) || defined(lint) 149 int tdebug = 0; 150 int lodebug = 0; 151 int faultdebug = 0; 152 #else 153 #define tdebug 0 154 #define lodebug 0 155 #define faultdebug 0 156 #endif /* defined(TRAPDEBUG) || defined(lint) */ 157 158 #if defined(TRAPTRACE) 159 /* 160 * trap trace record for cpu0 is allocated here. 161 * trap trace records for non-boot cpus are allocated in mp_startup_init(). 162 */ 163 static trap_trace_rec_t trap_tr0[TRAPTR_NENT]; 164 trap_trace_ctl_t trap_trace_ctl[NCPU] = { 165 { 166 (uintptr_t)trap_tr0, /* next record */ 167 (uintptr_t)trap_tr0, /* first record */ 168 (uintptr_t)(trap_tr0 + TRAPTR_NENT), /* limit */ 169 (uintptr_t)0 /* current */ 170 }, 171 }; 172 173 /* 174 * default trap buffer size 175 */ 176 size_t trap_trace_bufsize = TRAPTR_NENT * sizeof (trap_trace_rec_t); 177 int trap_trace_freeze = 0; 178 int trap_trace_off = 0; 179 180 /* 181 * A dummy TRAPTRACE entry to use after death. 182 */ 183 trap_trace_rec_t trap_trace_postmort; 184 185 static void dump_ttrace(void); 186 #endif /* TRAPTRACE */ 187 static void dumpregs(struct regs *); 188 static void showregs(uint_t, struct regs *, caddr_t); 189 static int kern_gpfault(struct regs *); 190 191 /*ARGSUSED*/ 192 static int 193 die(uint_t type, struct regs *rp, caddr_t addr, processorid_t cpuid) 194 { 195 struct panic_trap_info ti; 196 const char *trap_name, *trap_mnemonic; 197 198 if (type < TRAP_TYPES) { 199 trap_name = trap_type[type]; 200 trap_mnemonic = trap_type_mnemonic[type]; 201 } else { 202 trap_name = "trap"; 203 trap_mnemonic = "-"; 204 } 205 206 #ifdef TRAPTRACE 207 TRAPTRACE_FREEZE; 208 #endif 209 210 ti.trap_regs = rp; 211 ti.trap_type = type & ~USER; 212 ti.trap_addr = addr; 213 214 curthread->t_panic_trap = &ti; 215 216 if (type == T_PGFLT && addr < (caddr_t)KERNELBASE) { 217 panic("BAD TRAP: type=%x (#%s %s) rp=%p addr=%p " 218 "occurred in module \"%s\" due to %s", 219 type, trap_mnemonic, trap_name, (void *)rp, (void *)addr, 220 mod_containing_pc((caddr_t)rp->r_pc), 221 addr < (caddr_t)PAGESIZE ? 222 "a NULL pointer dereference" : 223 "an illegal access to a user address"); 224 } else 225 panic("BAD TRAP: type=%x (#%s %s) rp=%p addr=%p", 226 type, trap_mnemonic, trap_name, (void *)rp, (void *)addr); 227 return (0); 228 } 229 230 /* 231 * Rewrite the instruction at pc to be an int $T_SYSCALLINT instruction. 232 * 233 * int <vector> is two bytes: 0xCD <vector> 234 */ 235 236 static int 237 rewrite_syscall(caddr_t pc) 238 { 239 uchar_t instr[SLOW_SCALL_SIZE] = { 0xCD, T_SYSCALLINT }; 240 241 if (uwrite(curthread->t_procp, instr, SLOW_SCALL_SIZE, 242 (uintptr_t)pc) != 0) 243 return (1); 244 245 return (0); 246 } 247 248 /* 249 * Test to see if the instruction at pc is sysenter or syscall. The second 250 * argument should be the x86 feature flag corresponding to the expected 251 * instruction. 252 * 253 * sysenter is two bytes: 0x0F 0x34 254 * syscall is two bytes: 0x0F 0x05 255 * int $T_SYSCALLINT is two bytes: 0xCD 0x91 256 */ 257 258 static int 259 instr_is_other_syscall(caddr_t pc, int which) 260 { 261 uchar_t instr[FAST_SCALL_SIZE]; 262 263 ASSERT(which == X86FSET_SEP || which == X86FSET_ASYSC || which == 0xCD); 264 265 if (copyin_nowatch(pc, (caddr_t)instr, FAST_SCALL_SIZE) != 0) 266 return (0); 267 268 switch (which) { 269 case X86FSET_SEP: 270 if (instr[0] == 0x0F && instr[1] == 0x34) 271 return (1); 272 break; 273 case X86FSET_ASYSC: 274 if (instr[0] == 0x0F && instr[1] == 0x05) 275 return (1); 276 break; 277 case 0xCD: 278 if (instr[0] == 0xCD && instr[1] == T_SYSCALLINT) 279 return (1); 280 break; 281 } 282 283 return (0); 284 } 285 286 static const char * 287 syscall_insn_string(int syscall_insn) 288 { 289 switch (syscall_insn) { 290 case X86FSET_SEP: 291 return ("sysenter"); 292 case X86FSET_ASYSC: 293 return ("syscall"); 294 case 0xCD: 295 return ("int"); 296 default: 297 return ("Unknown"); 298 } 299 } 300 301 static int 302 ldt_rewrite_syscall(struct regs *rp, proc_t *p, int syscall_insn) 303 { 304 caddr_t linearpc; 305 int return_code = 0; 306 307 mutex_enter(&p->p_ldtlock); /* Must be held across linear_pc() */ 308 309 if (linear_pc(rp, p, &linearpc) == 0) { 310 311 /* 312 * If another thread beat us here, it already changed 313 * this site to the slower (int) syscall instruction. 314 */ 315 if (instr_is_other_syscall(linearpc, 0xCD)) { 316 return_code = 1; 317 } else if (instr_is_other_syscall(linearpc, syscall_insn)) { 318 319 if (rewrite_syscall(linearpc) == 0) { 320 return_code = 1; 321 } 322 #ifdef DEBUG 323 else 324 cmn_err(CE_WARN, "failed to rewrite %s " 325 "instruction in process %d", 326 syscall_insn_string(syscall_insn), 327 p->p_pid); 328 #endif /* DEBUG */ 329 } 330 } 331 332 mutex_exit(&p->p_ldtlock); /* Must be held across linear_pc() */ 333 334 return (return_code); 335 } 336 337 /* 338 * Test to see if the instruction at pc is a system call instruction. 339 * 340 * The bytes of an lcall instruction used for the syscall trap. 341 * static uchar_t lcall[7] = { 0x9a, 0, 0, 0, 0, 0x7, 0 }; 342 * static uchar_t lcallalt[7] = { 0x9a, 0, 0, 0, 0, 0x27, 0 }; 343 */ 344 345 #define LCALLSIZE 7 346 347 static int 348 instr_is_lcall_syscall(caddr_t pc) 349 { 350 uchar_t instr[LCALLSIZE]; 351 352 if (copyin_nowatch(pc, (caddr_t)instr, LCALLSIZE) == 0 && 353 instr[0] == 0x9a && 354 instr[1] == 0 && 355 instr[2] == 0 && 356 instr[3] == 0 && 357 instr[4] == 0 && 358 (instr[5] == 0x7 || instr[5] == 0x27) && 359 instr[6] == 0) 360 return (1); 361 362 return (0); 363 } 364 365 #ifdef __amd64 366 367 /* 368 * In the first revisions of amd64 CPUs produced by AMD, the LAHF and 369 * SAHF instructions were not implemented in 64-bit mode. Later revisions 370 * did implement these instructions. An extension to the cpuid instruction 371 * was added to check for the capability of executing these instructions 372 * in 64-bit mode. 373 * 374 * Intel originally did not implement these instructions in EM64T either, 375 * but added them in later revisions. 376 * 377 * So, there are different chip revisions by both vendors out there that 378 * may or may not implement these instructions. The easy solution is to 379 * just always emulate these instructions on demand. 380 * 381 * SAHF == store %ah in the lower 8 bits of %rflags (opcode 0x9e) 382 * LAHF == load the lower 8 bits of %rflags into %ah (opcode 0x9f) 383 */ 384 385 #define LSAHFSIZE 1 386 387 static int 388 instr_is_lsahf(caddr_t pc, uchar_t *instr) 389 { 390 if (copyin_nowatch(pc, (caddr_t)instr, LSAHFSIZE) == 0 && 391 (*instr == 0x9e || *instr == 0x9f)) 392 return (1); 393 return (0); 394 } 395 396 /* 397 * Emulate the LAHF and SAHF instructions. The reference manuals define 398 * these instructions to always load/store bit 1 as a 1, and bits 3 and 5 399 * as a 0. The other, defined, bits are copied (the PS_ICC bits and PS_P). 400 * 401 * Note that %ah is bits 8-15 of %rax. 402 */ 403 static void 404 emulate_lsahf(struct regs *rp, uchar_t instr) 405 { 406 if (instr == 0x9e) { 407 /* sahf. Copy bits from %ah to flags. */ 408 rp->r_ps = (rp->r_ps & ~0xff) | 409 ((rp->r_rax >> 8) & PSL_LSAHFMASK) | PS_MB1; 410 } else { 411 /* lahf. Copy bits from flags to %ah. */ 412 rp->r_rax = (rp->r_rax & ~0xff00) | 413 (((rp->r_ps & PSL_LSAHFMASK) | PS_MB1) << 8); 414 } 415 rp->r_pc += LSAHFSIZE; 416 } 417 #endif /* __amd64 */ 418 419 #ifdef OPTERON_ERRATUM_91 420 421 /* 422 * Test to see if the instruction at pc is a prefetch instruction. 423 * 424 * The first byte of prefetch instructions is always 0x0F. 425 * The second byte is 0x18 for regular prefetch or 0x0D for AMD 3dnow prefetch. 426 * The third byte (ModRM) contains the register field bits (bits 3-5). 427 * These bits must be between 0 and 3 inclusive for regular prefetch and 428 * 0 and 1 inclusive for AMD 3dnow prefetch. 429 * 430 * In 64-bit mode, there may be a one-byte REX prefex (0x40-0x4F). 431 */ 432 433 static int 434 cmp_to_prefetch(uchar_t *p) 435 { 436 #ifdef _LP64 437 if ((p[0] & 0xF0) == 0x40) /* 64-bit REX prefix */ 438 p++; 439 #endif 440 return ((p[0] == 0x0F && p[1] == 0x18 && ((p[2] >> 3) & 7) <= 3) || 441 (p[0] == 0x0F && p[1] == 0x0D && ((p[2] >> 3) & 7) <= 1)); 442 } 443 444 static int 445 instr_is_prefetch(caddr_t pc) 446 { 447 uchar_t instr[4]; /* optional REX prefix plus 3-byte opcode */ 448 449 return (copyin_nowatch(pc, instr, sizeof (instr)) == 0 && 450 cmp_to_prefetch(instr)); 451 } 452 453 #endif /* OPTERON_ERRATUM_91 */ 454 455 /* 456 * Called from the trap handler when a processor trap occurs. 457 * 458 * Note: All user-level traps that might call stop() must exit 459 * trap() by 'goto out' or by falling through. 460 * Note Also: trap() is usually called with interrupts enabled, (PS_IE == 1) 461 * however, there are paths that arrive here with PS_IE == 0 so special care 462 * must be taken in those cases. 463 */ 464 void 465 trap(struct regs *rp, caddr_t addr, processorid_t cpuid) 466 { 467 kthread_t *ct = curthread; 468 enum seg_rw rw; 469 unsigned type; 470 proc_t *p = ttoproc(ct); 471 klwp_t *lwp = ttolwp(ct); 472 uintptr_t lofault; 473 label_t *onfault; 474 faultcode_t pagefault(), res, errcode; 475 enum fault_type fault_type; 476 k_siginfo_t siginfo; 477 uint_t fault = 0; 478 int mstate; 479 int sicode = 0; 480 int watchcode; 481 int watchpage; 482 caddr_t vaddr; 483 int singlestep_twiddle; 484 size_t sz; 485 int ta; 486 #ifdef __amd64 487 uchar_t instr; 488 #endif 489 490 ASSERT_STACK_ALIGNED(); 491 492 type = rp->r_trapno; 493 CPU_STATS_ADDQ(CPU, sys, trap, 1); 494 ASSERT(ct->t_schedflag & TS_DONT_SWAP); 495 496 if (type == T_PGFLT) { 497 498 errcode = rp->r_err; 499 if (errcode & PF_ERR_WRITE) 500 rw = S_WRITE; 501 else if ((caddr_t)rp->r_pc == addr || 502 (mmu.pt_nx != 0 && (errcode & PF_ERR_EXEC))) 503 rw = S_EXEC; 504 else 505 rw = S_READ; 506 507 #if defined(__i386) 508 /* 509 * Pentium Pro work-around 510 */ 511 if ((errcode & PF_ERR_PROT) && pentiumpro_bug4046376) { 512 uint_t attr; 513 uint_t priv_violation; 514 uint_t access_violation; 515 516 if (hat_getattr(addr < (caddr_t)kernelbase ? 517 curproc->p_as->a_hat : kas.a_hat, addr, &attr) 518 == -1) { 519 errcode &= ~PF_ERR_PROT; 520 } else { 521 priv_violation = (errcode & PF_ERR_USER) && 522 !(attr & PROT_USER); 523 access_violation = (errcode & PF_ERR_WRITE) && 524 !(attr & PROT_WRITE); 525 if (!priv_violation && !access_violation) 526 goto cleanup; 527 } 528 } 529 #endif /* __i386 */ 530 531 } else if (type == T_SGLSTP && lwp != NULL) 532 lwp->lwp_pcb.pcb_drstat = (uintptr_t)addr; 533 534 if (tdebug) 535 showregs(type, rp, addr); 536 537 if (USERMODE(rp->r_cs)) { 538 /* 539 * Set up the current cred to use during this trap. u_cred 540 * no longer exists. t_cred is used instead. 541 * The current process credential applies to the thread for 542 * the entire trap. If trapping from the kernel, this 543 * should already be set up. 544 */ 545 if (ct->t_cred != p->p_cred) { 546 cred_t *oldcred = ct->t_cred; 547 /* 548 * DTrace accesses t_cred in probe context. t_cred 549 * must always be either NULL, or point to a valid, 550 * allocated cred structure. 551 */ 552 ct->t_cred = crgetcred(); 553 crfree(oldcred); 554 } 555 ASSERT(lwp != NULL); 556 type |= USER; 557 ASSERT(lwptoregs(lwp) == rp); 558 lwp->lwp_state = LWP_SYS; 559 560 switch (type) { 561 case T_PGFLT + USER: 562 if ((caddr_t)rp->r_pc == addr) 563 mstate = LMS_TFAULT; 564 else 565 mstate = LMS_DFAULT; 566 break; 567 default: 568 mstate = LMS_TRAP; 569 break; 570 } 571 /* Kernel probe */ 572 TNF_PROBE_1(thread_state, "thread", /* CSTYLED */, 573 tnf_microstate, state, mstate); 574 mstate = new_mstate(ct, mstate); 575 576 bzero(&siginfo, sizeof (siginfo)); 577 } 578 579 switch (type) { 580 case T_PGFLT + USER: 581 case T_SGLSTP: 582 case T_SGLSTP + USER: 583 case T_BPTFLT + USER: 584 break; 585 586 default: 587 FTRACE_2("trap(): type=0x%lx, regs=0x%lx", 588 (ulong_t)type, (ulong_t)rp); 589 break; 590 } 591 592 switch (type) { 593 case T_SIMDFPE: 594 /* Make sure we enable interrupts before die()ing */ 595 sti(); /* The SIMD exception comes in via cmninttrap */ 596 /*FALLTHROUGH*/ 597 default: 598 if (type & USER) { 599 if (tudebug) 600 showregs(type, rp, (caddr_t)0); 601 printf("trap: Unknown trap type %d in user mode\n", 602 type & ~USER); 603 siginfo.si_signo = SIGILL; 604 siginfo.si_code = ILL_ILLTRP; 605 siginfo.si_addr = (caddr_t)rp->r_pc; 606 siginfo.si_trapno = type & ~USER; 607 fault = FLTILL; 608 break; 609 } else { 610 (void) die(type, rp, addr, cpuid); 611 /*NOTREACHED*/ 612 } 613 614 case T_PGFLT: /* system page fault */ 615 /* 616 * If we're under on_trap() protection (see <sys/ontrap.h>), 617 * set ot_trap and bounce back to the on_trap() call site 618 * via the installed trampoline. 619 */ 620 if ((ct->t_ontrap != NULL) && 621 (ct->t_ontrap->ot_prot & OT_DATA_ACCESS)) { 622 ct->t_ontrap->ot_trap |= OT_DATA_ACCESS; 623 rp->r_pc = ct->t_ontrap->ot_trampoline; 624 goto cleanup; 625 } 626 627 /* 628 * If we have an Instruction fault in kernel mode, then that 629 * means we've tried to execute a user page (SMEP) or both of 630 * PAE and NXE are enabled. In either case, given that it's a 631 * kernel fault, we should panic immediately and not try to make 632 * any more forward progress. This indicates a bug in the 633 * kernel, which if execution continued, could be exploited to 634 * wreak havoc on the system. 635 */ 636 if (errcode & PF_ERR_EXEC) { 637 (void) die(type, rp, addr, cpuid); 638 } 639 640 /* 641 * We need to check if SMAP is in play. If SMAP is in play, then 642 * any access to a user page will show up as a protection 643 * violation. To see if SMAP is enabled we first check if it's a 644 * user address and whether we have the feature flag set. If we 645 * do and the interrupted registers do not allow for user 646 * accesses (PS_ACHK is not enabled), then we need to die 647 * immediately. 648 */ 649 if (addr < (caddr_t)kernelbase && 650 is_x86_feature(x86_featureset, X86FSET_SMAP) == B_TRUE && 651 (rp->r_ps & PS_ACHK) == 0) { 652 (void) die(type, rp, addr, cpuid); 653 } 654 655 /* 656 * See if we can handle as pagefault. Save lofault and onfault 657 * across this. Here we assume that an address less than 658 * KERNELBASE is a user fault. We can do this as copy.s 659 * routines verify that the starting address is less than 660 * KERNELBASE before starting and because we know that we 661 * always have KERNELBASE mapped as invalid to serve as a 662 * "barrier". 663 */ 664 lofault = ct->t_lofault; 665 onfault = ct->t_onfault; 666 ct->t_lofault = 0; 667 668 mstate = new_mstate(ct, LMS_KFAULT); 669 670 if (addr < (caddr_t)kernelbase) { 671 res = pagefault(addr, 672 (errcode & PF_ERR_PROT)? F_PROT: F_INVAL, rw, 0); 673 if (res == FC_NOMAP && 674 addr < p->p_usrstack && 675 grow(addr)) 676 res = 0; 677 } else { 678 res = pagefault(addr, 679 (errcode & PF_ERR_PROT)? F_PROT: F_INVAL, rw, 1); 680 } 681 (void) new_mstate(ct, mstate); 682 683 /* 684 * Restore lofault and onfault. If we resolved the fault, exit. 685 * If we didn't and lofault wasn't set, die. 686 */ 687 ct->t_lofault = lofault; 688 ct->t_onfault = onfault; 689 if (res == 0) 690 goto cleanup; 691 692 #if defined(OPTERON_ERRATUM_93) && defined(_LP64) 693 if (lofault == 0 && opteron_erratum_93) { 694 /* 695 * Workaround for Opteron Erratum 93. On return from 696 * a System Managment Interrupt at a HLT instruction 697 * the %rip might be truncated to a 32 bit value. 698 * BIOS is supposed to fix this, but some don't. 699 * If this occurs we simply restore the high order bits. 700 * The HLT instruction is 1 byte of 0xf4. 701 */ 702 uintptr_t rip = rp->r_pc; 703 704 if ((rip & 0xfffffffful) == rip) { 705 rip |= 0xfffffffful << 32; 706 if (hat_getpfnum(kas.a_hat, (caddr_t)rip) != 707 PFN_INVALID && 708 (*(uchar_t *)rip == 0xf4 || 709 *(uchar_t *)(rip - 1) == 0xf4)) { 710 rp->r_pc = rip; 711 goto cleanup; 712 } 713 } 714 } 715 #endif /* OPTERON_ERRATUM_93 && _LP64 */ 716 717 #ifdef OPTERON_ERRATUM_91 718 if (lofault == 0 && opteron_erratum_91) { 719 /* 720 * Workaround for Opteron Erratum 91. Prefetches may 721 * generate a page fault (they're not supposed to do 722 * that!). If this occurs we simply return back to the 723 * instruction. 724 */ 725 caddr_t pc = (caddr_t)rp->r_pc; 726 727 /* 728 * If the faulting PC is not mapped, this is a 729 * legitimate kernel page fault that must result in a 730 * panic. If the faulting PC is mapped, it could contain 731 * a prefetch instruction. Check for that here. 732 */ 733 if (hat_getpfnum(kas.a_hat, pc) != PFN_INVALID) { 734 if (cmp_to_prefetch((uchar_t *)pc)) { 735 #ifdef DEBUG 736 cmn_err(CE_WARN, "Opteron erratum 91 " 737 "occurred: kernel prefetch" 738 " at %p generated a page fault!", 739 (void *)rp->r_pc); 740 #endif /* DEBUG */ 741 goto cleanup; 742 } 743 } 744 (void) die(type, rp, addr, cpuid); 745 } 746 #endif /* OPTERON_ERRATUM_91 */ 747 748 if (lofault == 0) 749 (void) die(type, rp, addr, cpuid); 750 751 /* 752 * Cannot resolve fault. Return to lofault. 753 */ 754 if (lodebug) { 755 showregs(type, rp, addr); 756 traceregs(rp); 757 } 758 if (FC_CODE(res) == FC_OBJERR) 759 res = FC_ERRNO(res); 760 else 761 res = EFAULT; 762 rp->r_r0 = res; 763 rp->r_pc = ct->t_lofault; 764 goto cleanup; 765 766 case T_PGFLT + USER: /* user page fault */ 767 if (faultdebug) { 768 char *fault_str; 769 770 switch (rw) { 771 case S_READ: 772 fault_str = "read"; 773 break; 774 case S_WRITE: 775 fault_str = "write"; 776 break; 777 case S_EXEC: 778 fault_str = "exec"; 779 break; 780 default: 781 fault_str = ""; 782 break; 783 } 784 printf("user %s fault: addr=0x%lx errcode=0x%x\n", 785 fault_str, (uintptr_t)addr, errcode); 786 } 787 788 #if defined(OPTERON_ERRATUM_100) && defined(_LP64) 789 /* 790 * Workaround for AMD erratum 100 791 * 792 * A 32-bit process may receive a page fault on a non 793 * 32-bit address by mistake. The range of the faulting 794 * address will be 795 * 796 * 0xffffffff80000000 .. 0xffffffffffffffff or 797 * 0x0000000100000000 .. 0x000000017fffffff 798 * 799 * The fault is always due to an instruction fetch, however 800 * the value of r_pc should be correct (in 32 bit range), 801 * so we ignore the page fault on the bogus address. 802 */ 803 if (p->p_model == DATAMODEL_ILP32 && 804 (0xffffffff80000000 <= (uintptr_t)addr || 805 (0x100000000 <= (uintptr_t)addr && 806 (uintptr_t)addr <= 0x17fffffff))) { 807 if (!opteron_erratum_100) 808 panic("unexpected erratum #100"); 809 if (rp->r_pc <= 0xffffffff) 810 goto out; 811 } 812 #endif /* OPTERON_ERRATUM_100 && _LP64 */ 813 814 ASSERT(!(curthread->t_flag & T_WATCHPT)); 815 watchpage = (pr_watch_active(p) && pr_is_watchpage(addr, rw)); 816 #ifdef __i386 817 /* 818 * In 32-bit mode, the lcall (system call) instruction fetches 819 * one word from the stack, at the stack pointer, because of the 820 * way the call gate is constructed. This is a bogus 821 * read and should not be counted as a read watchpoint. 822 * We work around the problem here by testing to see if 823 * this situation applies and, if so, simply jumping to 824 * the code in locore.s that fields the system call trap. 825 * The registers on the stack are already set up properly 826 * due to the match between the call gate sequence and the 827 * trap gate sequence. We just have to adjust the pc. 828 */ 829 if (watchpage && addr == (caddr_t)rp->r_sp && 830 rw == S_READ && instr_is_lcall_syscall((caddr_t)rp->r_pc)) { 831 extern void watch_syscall(void); 832 833 rp->r_pc += LCALLSIZE; 834 watch_syscall(); /* never returns */ 835 /* NOTREACHED */ 836 } 837 #endif /* __i386 */ 838 vaddr = addr; 839 if (!watchpage || (sz = instr_size(rp, &vaddr, rw)) <= 0) 840 fault_type = (errcode & PF_ERR_PROT)? F_PROT: F_INVAL; 841 else if ((watchcode = pr_is_watchpoint(&vaddr, &ta, 842 sz, NULL, rw)) != 0) { 843 if (ta) { 844 do_watch_step(vaddr, sz, rw, 845 watchcode, rp->r_pc); 846 fault_type = F_INVAL; 847 } else { 848 bzero(&siginfo, sizeof (siginfo)); 849 siginfo.si_signo = SIGTRAP; 850 siginfo.si_code = watchcode; 851 siginfo.si_addr = vaddr; 852 siginfo.si_trapafter = 0; 853 siginfo.si_pc = (caddr_t)rp->r_pc; 854 fault = FLTWATCH; 855 break; 856 } 857 } else { 858 /* XXX pr_watch_emul() never succeeds (for now) */ 859 if (rw != S_EXEC && pr_watch_emul(rp, vaddr, rw)) 860 goto out; 861 do_watch_step(vaddr, sz, rw, 0, 0); 862 fault_type = F_INVAL; 863 } 864 865 res = pagefault(addr, fault_type, rw, 0); 866 867 /* 868 * If pagefault() succeeded, ok. 869 * Otherwise attempt to grow the stack. 870 */ 871 if (res == 0 || 872 (res == FC_NOMAP && 873 addr < p->p_usrstack && 874 grow(addr))) { 875 lwp->lwp_lastfault = FLTPAGE; 876 lwp->lwp_lastfaddr = addr; 877 if (prismember(&p->p_fltmask, FLTPAGE)) { 878 bzero(&siginfo, sizeof (siginfo)); 879 siginfo.si_addr = addr; 880 (void) stop_on_fault(FLTPAGE, &siginfo); 881 } 882 goto out; 883 } else if (res == FC_PROT && addr < p->p_usrstack && 884 (mmu.pt_nx != 0 && (errcode & PF_ERR_EXEC))) { 885 report_stack_exec(p, addr); 886 } 887 888 #ifdef OPTERON_ERRATUM_91 889 /* 890 * Workaround for Opteron Erratum 91. Prefetches may generate a 891 * page fault (they're not supposed to do that!). If this 892 * occurs we simply return back to the instruction. 893 * 894 * We rely on copyin to properly fault in the page with r_pc. 895 */ 896 if (opteron_erratum_91 && 897 addr != (caddr_t)rp->r_pc && 898 instr_is_prefetch((caddr_t)rp->r_pc)) { 899 #ifdef DEBUG 900 cmn_err(CE_WARN, "Opteron erratum 91 occurred: " 901 "prefetch at %p in pid %d generated a trap!", 902 (void *)rp->r_pc, p->p_pid); 903 #endif /* DEBUG */ 904 goto out; 905 } 906 #endif /* OPTERON_ERRATUM_91 */ 907 908 if (tudebug) 909 showregs(type, rp, addr); 910 /* 911 * In the case where both pagefault and grow fail, 912 * set the code to the value provided by pagefault. 913 * We map all errors returned from pagefault() to SIGSEGV. 914 */ 915 bzero(&siginfo, sizeof (siginfo)); 916 siginfo.si_addr = addr; 917 switch (FC_CODE(res)) { 918 case FC_HWERR: 919 case FC_NOSUPPORT: 920 siginfo.si_signo = SIGBUS; 921 siginfo.si_code = BUS_ADRERR; 922 fault = FLTACCESS; 923 break; 924 case FC_ALIGN: 925 siginfo.si_signo = SIGBUS; 926 siginfo.si_code = BUS_ADRALN; 927 fault = FLTACCESS; 928 break; 929 case FC_OBJERR: 930 if ((siginfo.si_errno = FC_ERRNO(res)) != EINTR) { 931 siginfo.si_signo = SIGBUS; 932 siginfo.si_code = BUS_OBJERR; 933 fault = FLTACCESS; 934 } 935 break; 936 default: /* FC_NOMAP or FC_PROT */ 937 siginfo.si_signo = SIGSEGV; 938 siginfo.si_code = 939 (res == FC_NOMAP)? SEGV_MAPERR : SEGV_ACCERR; 940 fault = FLTBOUNDS; 941 break; 942 } 943 break; 944 945 case T_ILLINST + USER: /* invalid opcode fault */ 946 /* 947 * If the syscall instruction is disabled due to LDT usage, a 948 * user program that attempts to execute it will trigger a #ud 949 * trap. Check for that case here. If this occurs on a CPU which 950 * doesn't even support syscall, the result of all of this will 951 * be to emulate that particular instruction. 952 */ 953 if (p->p_ldt != NULL && 954 ldt_rewrite_syscall(rp, p, X86FSET_ASYSC)) 955 goto out; 956 957 #ifdef __amd64 958 /* 959 * Emulate the LAHF and SAHF instructions if needed. 960 * See the instr_is_lsahf function for details. 961 */ 962 if (p->p_model == DATAMODEL_LP64 && 963 instr_is_lsahf((caddr_t)rp->r_pc, &instr)) { 964 emulate_lsahf(rp, instr); 965 goto out; 966 } 967 #endif 968 969 /*FALLTHROUGH*/ 970 971 if (tudebug) 972 showregs(type, rp, (caddr_t)0); 973 siginfo.si_signo = SIGILL; 974 siginfo.si_code = ILL_ILLOPC; 975 siginfo.si_addr = (caddr_t)rp->r_pc; 976 fault = FLTILL; 977 break; 978 979 case T_ZERODIV + USER: /* integer divide by zero */ 980 if (tudebug && tudebugfpe) 981 showregs(type, rp, (caddr_t)0); 982 siginfo.si_signo = SIGFPE; 983 siginfo.si_code = FPE_INTDIV; 984 siginfo.si_addr = (caddr_t)rp->r_pc; 985 fault = FLTIZDIV; 986 break; 987 988 case T_OVFLW + USER: /* integer overflow */ 989 if (tudebug && tudebugfpe) 990 showregs(type, rp, (caddr_t)0); 991 siginfo.si_signo = SIGFPE; 992 siginfo.si_code = FPE_INTOVF; 993 siginfo.si_addr = (caddr_t)rp->r_pc; 994 fault = FLTIOVF; 995 break; 996 997 case T_NOEXTFLT + USER: /* math coprocessor not available */ 998 if (tudebug && tudebugfpe) 999 showregs(type, rp, addr); 1000 if (fpnoextflt(rp)) { 1001 siginfo.si_signo = SIGILL; 1002 siginfo.si_code = ILL_ILLOPC; 1003 siginfo.si_addr = (caddr_t)rp->r_pc; 1004 fault = FLTILL; 1005 } 1006 break; 1007 1008 case T_EXTOVRFLT: /* extension overrun fault */ 1009 /* check if we took a kernel trap on behalf of user */ 1010 { 1011 extern void ndptrap_frstor(void); 1012 if (rp->r_pc != (uintptr_t)ndptrap_frstor) { 1013 sti(); /* T_EXTOVRFLT comes in via cmninttrap */ 1014 (void) die(type, rp, addr, cpuid); 1015 } 1016 type |= USER; 1017 } 1018 /*FALLTHROUGH*/ 1019 case T_EXTOVRFLT + USER: /* extension overrun fault */ 1020 if (tudebug && tudebugfpe) 1021 showregs(type, rp, addr); 1022 if (fpextovrflt(rp)) { 1023 siginfo.si_signo = SIGSEGV; 1024 siginfo.si_code = SEGV_MAPERR; 1025 siginfo.si_addr = (caddr_t)rp->r_pc; 1026 fault = FLTBOUNDS; 1027 } 1028 break; 1029 1030 case T_EXTERRFLT: /* x87 floating point exception pending */ 1031 /* check if we took a kernel trap on behalf of user */ 1032 { 1033 extern void ndptrap_frstor(void); 1034 if (rp->r_pc != (uintptr_t)ndptrap_frstor) { 1035 sti(); /* T_EXTERRFLT comes in via cmninttrap */ 1036 (void) die(type, rp, addr, cpuid); 1037 } 1038 type |= USER; 1039 } 1040 /*FALLTHROUGH*/ 1041 1042 case T_EXTERRFLT + USER: /* x87 floating point exception pending */ 1043 if (tudebug && tudebugfpe) 1044 showregs(type, rp, addr); 1045 if (sicode = fpexterrflt(rp)) { 1046 siginfo.si_signo = SIGFPE; 1047 siginfo.si_code = sicode; 1048 siginfo.si_addr = (caddr_t)rp->r_pc; 1049 fault = FLTFPE; 1050 } 1051 break; 1052 1053 case T_SIMDFPE + USER: /* SSE and SSE2 exceptions */ 1054 if (tudebug && tudebugsse) 1055 showregs(type, rp, addr); 1056 if (!is_x86_feature(x86_featureset, X86FSET_SSE) && 1057 !is_x86_feature(x86_featureset, X86FSET_SSE2)) { 1058 /* 1059 * There are rumours that some user instructions 1060 * on older CPUs can cause this trap to occur; in 1061 * which case send a SIGILL instead of a SIGFPE. 1062 */ 1063 siginfo.si_signo = SIGILL; 1064 siginfo.si_code = ILL_ILLTRP; 1065 siginfo.si_addr = (caddr_t)rp->r_pc; 1066 siginfo.si_trapno = type & ~USER; 1067 fault = FLTILL; 1068 } else if ((sicode = fpsimderrflt(rp)) != 0) { 1069 siginfo.si_signo = SIGFPE; 1070 siginfo.si_code = sicode; 1071 siginfo.si_addr = (caddr_t)rp->r_pc; 1072 fault = FLTFPE; 1073 } 1074 1075 sti(); /* The SIMD exception comes in via cmninttrap */ 1076 break; 1077 1078 case T_BPTFLT: /* breakpoint trap */ 1079 /* 1080 * Kernel breakpoint traps should only happen when kmdb is 1081 * active, and even then, it'll have interposed on the IDT, so 1082 * control won't get here. If it does, we've hit a breakpoint 1083 * without the debugger, which is very strange, and very 1084 * fatal. 1085 */ 1086 if (tudebug && tudebugbpt) 1087 showregs(type, rp, (caddr_t)0); 1088 1089 (void) die(type, rp, addr, cpuid); 1090 break; 1091 1092 case T_SGLSTP: /* single step/hw breakpoint exception */ 1093 1094 /* Now evaluate how we got here */ 1095 if (lwp != NULL && (lwp->lwp_pcb.pcb_drstat & DR_SINGLESTEP)) { 1096 /* 1097 * i386 single-steps even through lcalls which 1098 * change the privilege level. So we take a trap at 1099 * the first instruction in privileged mode. 1100 * 1101 * Set a flag to indicate that upon completion of 1102 * the system call, deal with the single-step trap. 1103 * 1104 * The same thing happens for sysenter, too. 1105 */ 1106 singlestep_twiddle = 0; 1107 if (rp->r_pc == (uintptr_t)sys_sysenter || 1108 rp->r_pc == (uintptr_t)brand_sys_sysenter) { 1109 singlestep_twiddle = 1; 1110 #if defined(__amd64) 1111 /* 1112 * Since we are already on the kernel's 1113 * %gs, on 64-bit systems the sysenter case 1114 * needs to adjust the pc to avoid 1115 * executing the swapgs instruction at the 1116 * top of the handler. 1117 */ 1118 if (rp->r_pc == (uintptr_t)sys_sysenter) 1119 rp->r_pc = (uintptr_t) 1120 _sys_sysenter_post_swapgs; 1121 else 1122 rp->r_pc = (uintptr_t) 1123 _brand_sys_sysenter_post_swapgs; 1124 #endif 1125 } 1126 #if defined(__i386) 1127 else if (rp->r_pc == (uintptr_t)sys_call || 1128 rp->r_pc == (uintptr_t)brand_sys_call) { 1129 singlestep_twiddle = 1; 1130 } 1131 #endif 1132 else { 1133 /* not on sysenter/syscall; uregs available */ 1134 if (tudebug && tudebugbpt) 1135 showregs(type, rp, (caddr_t)0); 1136 } 1137 if (singlestep_twiddle) { 1138 rp->r_ps &= ~PS_T; /* turn off trace */ 1139 lwp->lwp_pcb.pcb_flags |= DEBUG_PENDING; 1140 ct->t_post_sys = 1; 1141 aston(curthread); 1142 goto cleanup; 1143 } 1144 } 1145 /* XXX - needs review on debugger interface? */ 1146 if (boothowto & RB_DEBUG) 1147 debug_enter((char *)NULL); 1148 else 1149 (void) die(type, rp, addr, cpuid); 1150 break; 1151 1152 case T_NMIFLT: /* NMI interrupt */ 1153 printf("Unexpected NMI in system mode\n"); 1154 goto cleanup; 1155 1156 case T_NMIFLT + USER: /* NMI interrupt */ 1157 printf("Unexpected NMI in user mode\n"); 1158 break; 1159 1160 case T_GPFLT: /* general protection violation */ 1161 /* 1162 * Any #GP that occurs during an on_trap .. no_trap bracket 1163 * with OT_DATA_ACCESS or OT_SEGMENT_ACCESS protection, 1164 * or in a on_fault .. no_fault bracket, is forgiven 1165 * and we trampoline. This protection is given regardless 1166 * of whether we are 32/64 bit etc - if a distinction is 1167 * required then define new on_trap protection types. 1168 * 1169 * On amd64, we can get a #gp from referencing addresses 1170 * in the virtual address hole e.g. from a copyin or in 1171 * update_sregs while updating user segment registers. 1172 * 1173 * On the 32-bit hypervisor we could also generate one in 1174 * mfn_to_pfn by reaching around or into where the hypervisor 1175 * lives which is protected by segmentation. 1176 */ 1177 1178 /* 1179 * If we're under on_trap() protection (see <sys/ontrap.h>), 1180 * set ot_trap and trampoline back to the on_trap() call site 1181 * for OT_DATA_ACCESS or OT_SEGMENT_ACCESS. 1182 */ 1183 if (ct->t_ontrap != NULL) { 1184 int ttype = ct->t_ontrap->ot_prot & 1185 (OT_DATA_ACCESS | OT_SEGMENT_ACCESS); 1186 1187 if (ttype != 0) { 1188 ct->t_ontrap->ot_trap |= ttype; 1189 if (tudebug) 1190 showregs(type, rp, (caddr_t)0); 1191 rp->r_pc = ct->t_ontrap->ot_trampoline; 1192 goto cleanup; 1193 } 1194 } 1195 1196 /* 1197 * If we're under lofault protection (copyin etc.), 1198 * longjmp back to lofault with an EFAULT. 1199 */ 1200 if (ct->t_lofault) { 1201 /* 1202 * Fault is not resolvable, so just return to lofault 1203 */ 1204 if (lodebug) { 1205 showregs(type, rp, addr); 1206 traceregs(rp); 1207 } 1208 rp->r_r0 = EFAULT; 1209 rp->r_pc = ct->t_lofault; 1210 goto cleanup; 1211 } 1212 1213 /* 1214 * We fall through to the next case, which repeats 1215 * the OT_SEGMENT_ACCESS check which we've already 1216 * done, so we'll always fall through to the 1217 * T_STKFLT case. 1218 */ 1219 /*FALLTHROUGH*/ 1220 case T_SEGFLT: /* segment not present fault */ 1221 /* 1222 * One example of this is #NP in update_sregs while 1223 * attempting to update a user segment register 1224 * that points to a descriptor that is marked not 1225 * present. 1226 */ 1227 if (ct->t_ontrap != NULL && 1228 ct->t_ontrap->ot_prot & OT_SEGMENT_ACCESS) { 1229 ct->t_ontrap->ot_trap |= OT_SEGMENT_ACCESS; 1230 if (tudebug) 1231 showregs(type, rp, (caddr_t)0); 1232 rp->r_pc = ct->t_ontrap->ot_trampoline; 1233 goto cleanup; 1234 } 1235 /*FALLTHROUGH*/ 1236 case T_STKFLT: /* stack fault */ 1237 case T_TSSFLT: /* invalid TSS fault */ 1238 if (tudebug) 1239 showregs(type, rp, (caddr_t)0); 1240 if (kern_gpfault(rp)) 1241 (void) die(type, rp, addr, cpuid); 1242 goto cleanup; 1243 1244 /* 1245 * ONLY 32-bit PROCESSES can USE a PRIVATE LDT! 64-bit apps 1246 * should have no need for them, so we put a stop to it here. 1247 * 1248 * So: not-present fault is ONLY valid for 32-bit processes with 1249 * a private LDT trying to do a system call. Emulate it. 1250 * 1251 * #gp fault is ONLY valid for 32-bit processes also, which DO NOT 1252 * have a private LDT, and are trying to do a system call. Emulate it. 1253 */ 1254 1255 case T_SEGFLT + USER: /* segment not present fault */ 1256 case T_GPFLT + USER: /* general protection violation */ 1257 #ifdef _SYSCALL32_IMPL 1258 if (p->p_model != DATAMODEL_NATIVE) { 1259 #endif /* _SYSCALL32_IMPL */ 1260 if (instr_is_lcall_syscall((caddr_t)rp->r_pc)) { 1261 if (type == T_SEGFLT + USER) 1262 ASSERT(p->p_ldt != NULL); 1263 1264 if ((p->p_ldt == NULL && type == T_GPFLT + USER) || 1265 type == T_SEGFLT + USER) { 1266 1267 /* 1268 * The user attempted a system call via the obsolete 1269 * call gate mechanism. Because the process doesn't have 1270 * an LDT (i.e. the ldtr contains 0), a #gp results. 1271 * Emulate the syscall here, just as we do above for a 1272 * #np trap. 1273 */ 1274 1275 /* 1276 * Since this is a not-present trap, rp->r_pc points to 1277 * the trapping lcall instruction. We need to bump it 1278 * to the next insn so the app can continue on. 1279 */ 1280 rp->r_pc += LCALLSIZE; 1281 lwp->lwp_regs = rp; 1282 1283 /* 1284 * Normally the microstate of the LWP is forced back to 1285 * LMS_USER by the syscall handlers. Emulate that 1286 * behavior here. 1287 */ 1288 mstate = LMS_USER; 1289 1290 dosyscall(); 1291 goto out; 1292 } 1293 } 1294 #ifdef _SYSCALL32_IMPL 1295 } 1296 #endif /* _SYSCALL32_IMPL */ 1297 /* 1298 * If the current process is using a private LDT and the 1299 * trapping instruction is sysenter, the sysenter instruction 1300 * has been disabled on the CPU because it destroys segment 1301 * registers. If this is the case, rewrite the instruction to 1302 * be a safe system call and retry it. If this occurs on a CPU 1303 * which doesn't even support sysenter, the result of all of 1304 * this will be to emulate that particular instruction. 1305 */ 1306 if (p->p_ldt != NULL && 1307 ldt_rewrite_syscall(rp, p, X86FSET_SEP)) 1308 goto out; 1309 1310 /*FALLTHROUGH*/ 1311 1312 case T_BOUNDFLT + USER: /* bound fault */ 1313 case T_STKFLT + USER: /* stack fault */ 1314 case T_TSSFLT + USER: /* invalid TSS fault */ 1315 if (tudebug) 1316 showregs(type, rp, (caddr_t)0); 1317 siginfo.si_signo = SIGSEGV; 1318 siginfo.si_code = SEGV_MAPERR; 1319 siginfo.si_addr = (caddr_t)rp->r_pc; 1320 fault = FLTBOUNDS; 1321 break; 1322 1323 case T_ALIGNMENT + USER: /* user alignment error (486) */ 1324 if (tudebug) 1325 showregs(type, rp, (caddr_t)0); 1326 bzero(&siginfo, sizeof (siginfo)); 1327 siginfo.si_signo = SIGBUS; 1328 siginfo.si_code = BUS_ADRALN; 1329 siginfo.si_addr = (caddr_t)rp->r_pc; 1330 fault = FLTACCESS; 1331 break; 1332 1333 case T_SGLSTP + USER: /* single step/hw breakpoint exception */ 1334 if (tudebug && tudebugbpt) 1335 showregs(type, rp, (caddr_t)0); 1336 1337 /* Was it single-stepping? */ 1338 if (lwp->lwp_pcb.pcb_drstat & DR_SINGLESTEP) { 1339 pcb_t *pcb = &lwp->lwp_pcb; 1340 1341 rp->r_ps &= ~PS_T; 1342 /* 1343 * If both NORMAL_STEP and WATCH_STEP are in effect, 1344 * give precedence to WATCH_STEP. If neither is set, 1345 * user must have set the PS_T bit in %efl; treat this 1346 * as NORMAL_STEP. 1347 */ 1348 if ((fault = undo_watch_step(&siginfo)) == 0 && 1349 ((pcb->pcb_flags & NORMAL_STEP) || 1350 !(pcb->pcb_flags & WATCH_STEP))) { 1351 siginfo.si_signo = SIGTRAP; 1352 siginfo.si_code = TRAP_TRACE; 1353 siginfo.si_addr = (caddr_t)rp->r_pc; 1354 fault = FLTTRACE; 1355 } 1356 pcb->pcb_flags &= ~(NORMAL_STEP|WATCH_STEP); 1357 } 1358 break; 1359 1360 case T_BPTFLT + USER: /* breakpoint trap */ 1361 if (tudebug && tudebugbpt) 1362 showregs(type, rp, (caddr_t)0); 1363 /* 1364 * int 3 (the breakpoint instruction) leaves the pc referring 1365 * to the address one byte after the breakpointed address. 1366 * If the P_PR_BPTADJ flag has been set via /proc, We adjust 1367 * it back so it refers to the breakpointed address. 1368 */ 1369 if (p->p_proc_flag & P_PR_BPTADJ) 1370 rp->r_pc--; 1371 siginfo.si_signo = SIGTRAP; 1372 siginfo.si_code = TRAP_BRKPT; 1373 siginfo.si_addr = (caddr_t)rp->r_pc; 1374 fault = FLTBPT; 1375 break; 1376 1377 case T_AST: 1378 /* 1379 * This occurs only after the cs register has been made to 1380 * look like a kernel selector, either through debugging or 1381 * possibly by functions like setcontext(). The thread is 1382 * about to cause a general protection fault at common_iret() 1383 * in locore. We let that happen immediately instead of 1384 * doing the T_AST processing. 1385 */ 1386 goto cleanup; 1387 1388 case T_AST + USER: /* profiling, resched, h/w error pseudo trap */ 1389 if (lwp->lwp_pcb.pcb_flags & ASYNC_HWERR) { 1390 proc_t *p = ttoproc(curthread); 1391 extern void print_msg_hwerr(ctid_t ct_id, proc_t *p); 1392 1393 lwp->lwp_pcb.pcb_flags &= ~ASYNC_HWERR; 1394 print_msg_hwerr(p->p_ct_process->conp_contract.ct_id, 1395 p); 1396 contract_process_hwerr(p->p_ct_process, p); 1397 siginfo.si_signo = SIGKILL; 1398 siginfo.si_code = SI_NOINFO; 1399 } else if (lwp->lwp_pcb.pcb_flags & CPC_OVERFLOW) { 1400 lwp->lwp_pcb.pcb_flags &= ~CPC_OVERFLOW; 1401 if (kcpc_overflow_ast()) { 1402 /* 1403 * Signal performance counter overflow 1404 */ 1405 if (tudebug) 1406 showregs(type, rp, (caddr_t)0); 1407 bzero(&siginfo, sizeof (siginfo)); 1408 siginfo.si_signo = SIGEMT; 1409 siginfo.si_code = EMT_CPCOVF; 1410 siginfo.si_addr = (caddr_t)rp->r_pc; 1411 fault = FLTCPCOVF; 1412 } 1413 } 1414 1415 break; 1416 } 1417 1418 /* 1419 * We can't get here from a system trap 1420 */ 1421 ASSERT(type & USER); 1422 1423 if (fault) { 1424 /* We took a fault so abort single step. */ 1425 lwp->lwp_pcb.pcb_flags &= ~(NORMAL_STEP|WATCH_STEP); 1426 /* 1427 * Remember the fault and fault adddress 1428 * for real-time (SIGPROF) profiling. 1429 */ 1430 lwp->lwp_lastfault = fault; 1431 lwp->lwp_lastfaddr = siginfo.si_addr; 1432 1433 DTRACE_PROC2(fault, int, fault, ksiginfo_t *, &siginfo); 1434 1435 /* 1436 * If a debugger has declared this fault to be an 1437 * event of interest, stop the lwp. Otherwise just 1438 * deliver the associated signal. 1439 */ 1440 if (siginfo.si_signo != SIGKILL && 1441 prismember(&p->p_fltmask, fault) && 1442 stop_on_fault(fault, &siginfo) == 0) 1443 siginfo.si_signo = 0; 1444 } 1445 1446 if (siginfo.si_signo) 1447 trapsig(&siginfo, (fault != FLTFPE && fault != FLTCPCOVF)); 1448 1449 if (lwp->lwp_oweupc) 1450 profil_tick(rp->r_pc); 1451 1452 if (ct->t_astflag | ct->t_sig_check) { 1453 /* 1454 * Turn off the AST flag before checking all the conditions that 1455 * may have caused an AST. This flag is on whenever a signal or 1456 * unusual condition should be handled after the next trap or 1457 * syscall. 1458 */ 1459 astoff(ct); 1460 /* 1461 * If a single-step trap occurred on a syscall (see above) 1462 * recognize it now. Do this before checking for signals 1463 * because deferred_singlestep_trap() may generate a SIGTRAP to 1464 * the LWP or may otherwise mark the LWP to call issig(FORREAL). 1465 */ 1466 if (lwp->lwp_pcb.pcb_flags & DEBUG_PENDING) 1467 deferred_singlestep_trap((caddr_t)rp->r_pc); 1468 1469 ct->t_sig_check = 0; 1470 1471 /* 1472 * As in other code paths that check against TP_CHANGEBIND, 1473 * we perform the check first without p_lock held -- only 1474 * acquiring p_lock in the unlikely event that it is indeed 1475 * set. This is safe because we are doing this after the 1476 * astoff(); if we are racing another thread setting 1477 * TP_CHANGEBIND on us, we will pick it up on a subsequent 1478 * lap through. 1479 */ 1480 if (curthread->t_proc_flag & TP_CHANGEBIND) { 1481 mutex_enter(&p->p_lock); 1482 if (curthread->t_proc_flag & TP_CHANGEBIND) { 1483 timer_lwpbind(); 1484 curthread->t_proc_flag &= ~TP_CHANGEBIND; 1485 } 1486 mutex_exit(&p->p_lock); 1487 } 1488 1489 /* 1490 * for kaio requests that are on the per-process poll queue, 1491 * aiop->aio_pollq, they're AIO_POLL bit is set, the kernel 1492 * should copyout their result_t to user memory. by copying 1493 * out the result_t, the user can poll on memory waiting 1494 * for the kaio request to complete. 1495 */ 1496 if (p->p_aio) 1497 aio_cleanup(0); 1498 /* 1499 * If this LWP was asked to hold, call holdlwp(), which will 1500 * stop. holdlwps() sets this up and calls pokelwps() which 1501 * sets the AST flag. 1502 * 1503 * Also check TP_EXITLWP, since this is used by fresh new LWPs 1504 * through lwp_rtt(). That flag is set if the lwp_create(2) 1505 * syscall failed after creating the LWP. 1506 */ 1507 if (ISHOLD(p)) 1508 holdlwp(); 1509 1510 /* 1511 * All code that sets signals and makes ISSIG evaluate true must 1512 * set t_astflag afterwards. 1513 */ 1514 if (ISSIG_PENDING(ct, lwp, p)) { 1515 if (issig(FORREAL)) 1516 psig(); 1517 ct->t_sig_check = 1; 1518 } 1519 1520 if (ct->t_rprof != NULL) { 1521 realsigprof(0, 0, 0); 1522 ct->t_sig_check = 1; 1523 } 1524 1525 /* 1526 * /proc can't enable/disable the trace bit itself 1527 * because that could race with the call gate used by 1528 * system calls via "lcall". If that happened, an 1529 * invalid EFLAGS would result. prstep()/prnostep() 1530 * therefore schedule an AST for the purpose. 1531 */ 1532 if (lwp->lwp_pcb.pcb_flags & REQUEST_STEP) { 1533 lwp->lwp_pcb.pcb_flags &= ~REQUEST_STEP; 1534 rp->r_ps |= PS_T; 1535 } 1536 if (lwp->lwp_pcb.pcb_flags & REQUEST_NOSTEP) { 1537 lwp->lwp_pcb.pcb_flags &= ~REQUEST_NOSTEP; 1538 rp->r_ps &= ~PS_T; 1539 } 1540 } 1541 1542 out: /* We can't get here from a system trap */ 1543 ASSERT(type & USER); 1544 1545 if (ISHOLD(p)) 1546 holdlwp(); 1547 1548 /* 1549 * Set state to LWP_USER here so preempt won't give us a kernel 1550 * priority if it occurs after this point. Call CL_TRAPRET() to 1551 * restore the user-level priority. 1552 * 1553 * It is important that no locks (other than spinlocks) be entered 1554 * after this point before returning to user mode (unless lwp_state 1555 * is set back to LWP_SYS). 1556 */ 1557 lwp->lwp_state = LWP_USER; 1558 1559 if (ct->t_trapret) { 1560 ct->t_trapret = 0; 1561 thread_lock(ct); 1562 CL_TRAPRET(ct); 1563 thread_unlock(ct); 1564 } 1565 if (CPU->cpu_runrun || curthread->t_schedflag & TS_ANYWAITQ) 1566 preempt(); 1567 prunstop(); 1568 (void) new_mstate(ct, mstate); 1569 1570 /* Kernel probe */ 1571 TNF_PROBE_1(thread_state, "thread", /* CSTYLED */, 1572 tnf_microstate, state, LMS_USER); 1573 1574 return; 1575 1576 cleanup: /* system traps end up here */ 1577 ASSERT(!(type & USER)); 1578 } 1579 1580 /* 1581 * Patch non-zero to disable preemption of threads in the kernel. 1582 */ 1583 int IGNORE_KERNEL_PREEMPTION = 0; /* XXX - delete this someday */ 1584 1585 struct kpreempt_cnts { /* kernel preemption statistics */ 1586 int kpc_idle; /* executing idle thread */ 1587 int kpc_intr; /* executing interrupt thread */ 1588 int kpc_clock; /* executing clock thread */ 1589 int kpc_blocked; /* thread has blocked preemption (t_preempt) */ 1590 int kpc_notonproc; /* thread is surrendering processor */ 1591 int kpc_inswtch; /* thread has ratified scheduling decision */ 1592 int kpc_prilevel; /* processor interrupt level is too high */ 1593 int kpc_apreempt; /* asynchronous preemption */ 1594 int kpc_spreempt; /* synchronous preemption */ 1595 } kpreempt_cnts; 1596 1597 /* 1598 * kernel preemption: forced rescheduling, preempt the running kernel thread. 1599 * the argument is old PIL for an interrupt, 1600 * or the distingished value KPREEMPT_SYNC. 1601 */ 1602 void 1603 kpreempt(int asyncspl) 1604 { 1605 kthread_t *ct = curthread; 1606 1607 if (IGNORE_KERNEL_PREEMPTION) { 1608 aston(CPU->cpu_dispthread); 1609 return; 1610 } 1611 1612 /* 1613 * Check that conditions are right for kernel preemption 1614 */ 1615 do { 1616 if (ct->t_preempt) { 1617 /* 1618 * either a privileged thread (idle, panic, interrupt) 1619 * or will check when t_preempt is lowered 1620 * We need to specifically handle the case where 1621 * the thread is in the middle of swtch (resume has 1622 * been called) and has its t_preempt set 1623 * [idle thread and a thread which is in kpreempt 1624 * already] and then a high priority thread is 1625 * available in the local dispatch queue. 1626 * In this case the resumed thread needs to take a 1627 * trap so that it can call kpreempt. We achieve 1628 * this by using siron(). 1629 * How do we detect this condition: 1630 * idle thread is running and is in the midst of 1631 * resume: curthread->t_pri == -1 && CPU->dispthread 1632 * != CPU->thread 1633 * Need to ensure that this happens only at high pil 1634 * resume is called at high pil 1635 * Only in resume_from_idle is the pil changed. 1636 */ 1637 if (ct->t_pri < 0) { 1638 kpreempt_cnts.kpc_idle++; 1639 if (CPU->cpu_dispthread != CPU->cpu_thread) 1640 siron(); 1641 } else if (ct->t_flag & T_INTR_THREAD) { 1642 kpreempt_cnts.kpc_intr++; 1643 if (ct->t_pil == CLOCK_LEVEL) 1644 kpreempt_cnts.kpc_clock++; 1645 } else { 1646 kpreempt_cnts.kpc_blocked++; 1647 if (CPU->cpu_dispthread != CPU->cpu_thread) 1648 siron(); 1649 } 1650 aston(CPU->cpu_dispthread); 1651 return; 1652 } 1653 if (ct->t_state != TS_ONPROC || 1654 ct->t_disp_queue != CPU->cpu_disp) { 1655 /* this thread will be calling swtch() shortly */ 1656 kpreempt_cnts.kpc_notonproc++; 1657 if (CPU->cpu_thread != CPU->cpu_dispthread) { 1658 /* already in swtch(), force another */ 1659 kpreempt_cnts.kpc_inswtch++; 1660 siron(); 1661 } 1662 return; 1663 } 1664 if (getpil() >= DISP_LEVEL) { 1665 /* 1666 * We can't preempt this thread if it is at 1667 * a PIL >= DISP_LEVEL since it may be holding 1668 * a spin lock (like sched_lock). 1669 */ 1670 siron(); /* check back later */ 1671 kpreempt_cnts.kpc_prilevel++; 1672 return; 1673 } 1674 if (!interrupts_enabled()) { 1675 /* 1676 * Can't preempt while running with ints disabled 1677 */ 1678 kpreempt_cnts.kpc_prilevel++; 1679 return; 1680 } 1681 if (asyncspl != KPREEMPT_SYNC) 1682 kpreempt_cnts.kpc_apreempt++; 1683 else 1684 kpreempt_cnts.kpc_spreempt++; 1685 1686 ct->t_preempt++; 1687 preempt(); 1688 ct->t_preempt--; 1689 } while (CPU->cpu_kprunrun); 1690 } 1691 1692 /* 1693 * Print out debugging info. 1694 */ 1695 static void 1696 showregs(uint_t type, struct regs *rp, caddr_t addr) 1697 { 1698 int s; 1699 1700 s = spl7(); 1701 type &= ~USER; 1702 if (PTOU(curproc)->u_comm[0]) 1703 printf("%s: ", PTOU(curproc)->u_comm); 1704 if (type < TRAP_TYPES) 1705 printf("#%s %s\n", trap_type_mnemonic[type], trap_type[type]); 1706 else 1707 switch (type) { 1708 case T_SYSCALL: 1709 printf("Syscall Trap:\n"); 1710 break; 1711 case T_AST: 1712 printf("AST\n"); 1713 break; 1714 default: 1715 printf("Bad Trap = %d\n", type); 1716 break; 1717 } 1718 if (type == T_PGFLT) { 1719 printf("Bad %s fault at addr=0x%lx\n", 1720 USERMODE(rp->r_cs) ? "user": "kernel", (uintptr_t)addr); 1721 } else if (addr) { 1722 printf("addr=0x%lx\n", (uintptr_t)addr); 1723 } 1724 1725 printf("pid=%d, pc=0x%lx, sp=0x%lx, eflags=0x%lx\n", 1726 (ttoproc(curthread) && ttoproc(curthread)->p_pidp) ? 1727 ttoproc(curthread)->p_pid : 0, rp->r_pc, rp->r_sp, rp->r_ps); 1728 1729 #if defined(__lint) 1730 /* 1731 * this clause can be deleted when lint bug 4870403 is fixed 1732 * (lint thinks that bit 32 is illegal in a %b format string) 1733 */ 1734 printf("cr0: %x cr4: %b\n", 1735 (uint_t)getcr0(), (uint_t)getcr4(), FMT_CR4); 1736 #else 1737 printf("cr0: %b cr4: %b\n", 1738 (uint_t)getcr0(), FMT_CR0, (uint_t)getcr4(), FMT_CR4); 1739 #endif /* __lint */ 1740 1741 printf("cr2: %lx", getcr2()); 1742 #if !defined(__xpv) 1743 printf("cr3: %lx", getcr3()); 1744 #if defined(__amd64) 1745 printf("cr8: %lx\n", getcr8()); 1746 #endif 1747 #endif 1748 printf("\n"); 1749 1750 dumpregs(rp); 1751 splx(s); 1752 } 1753 1754 static void 1755 dumpregs(struct regs *rp) 1756 { 1757 #if defined(__amd64) 1758 const char fmt[] = "\t%3s: %16lx %3s: %16lx %3s: %16lx\n"; 1759 1760 printf(fmt, "rdi", rp->r_rdi, "rsi", rp->r_rsi, "rdx", rp->r_rdx); 1761 printf(fmt, "rcx", rp->r_rcx, " r8", rp->r_r8, " r9", rp->r_r9); 1762 printf(fmt, "rax", rp->r_rax, "rbx", rp->r_rbx, "rbp", rp->r_rbp); 1763 printf(fmt, "r10", rp->r_r10, "r11", rp->r_r11, "r12", rp->r_r12); 1764 printf(fmt, "r13", rp->r_r13, "r14", rp->r_r14, "r15", rp->r_r15); 1765 1766 printf(fmt, "fsb", rdmsr(MSR_AMD_FSBASE), "gsb", rdmsr(MSR_AMD_GSBASE), 1767 " ds", rp->r_ds); 1768 printf(fmt, " es", rp->r_es, " fs", rp->r_fs, " gs", rp->r_gs); 1769 1770 printf(fmt, "trp", rp->r_trapno, "err", rp->r_err, "rip", rp->r_rip); 1771 printf(fmt, " cs", rp->r_cs, "rfl", rp->r_rfl, "rsp", rp->r_rsp); 1772 1773 printf("\t%3s: %16lx\n", " ss", rp->r_ss); 1774 1775 #elif defined(__i386) 1776 const char fmt[] = "\t%3s: %8lx %3s: %8lx %3s: %8lx %3s: %8lx\n"; 1777 1778 printf(fmt, " gs", rp->r_gs, " fs", rp->r_fs, 1779 " es", rp->r_es, " ds", rp->r_ds); 1780 printf(fmt, "edi", rp->r_edi, "esi", rp->r_esi, 1781 "ebp", rp->r_ebp, "esp", rp->r_esp); 1782 printf(fmt, "ebx", rp->r_ebx, "edx", rp->r_edx, 1783 "ecx", rp->r_ecx, "eax", rp->r_eax); 1784 printf(fmt, "trp", rp->r_trapno, "err", rp->r_err, 1785 "eip", rp->r_eip, " cs", rp->r_cs); 1786 printf("\t%3s: %8lx %3s: %8lx %3s: %8lx\n", 1787 "efl", rp->r_efl, "usp", rp->r_uesp, " ss", rp->r_ss); 1788 1789 #endif /* __i386 */ 1790 } 1791 1792 /* 1793 * Test to see if the instruction is iret on i386 or iretq on amd64. 1794 * 1795 * On the hypervisor we can only test for nopop_sys_rtt_syscall. If true 1796 * then we are in the context of hypervisor's failsafe handler because it 1797 * tried to iret and failed due to a bad selector. See xen_failsafe_callback. 1798 */ 1799 static int 1800 instr_is_iret(caddr_t pc) 1801 { 1802 1803 #if defined(__xpv) 1804 extern void nopop_sys_rtt_syscall(void); 1805 return ((pc == (caddr_t)nopop_sys_rtt_syscall) ? 1 : 0); 1806 1807 #else 1808 1809 #if defined(__amd64) 1810 static const uint8_t iret_insn[2] = { 0x48, 0xcf }; /* iretq */ 1811 1812 #elif defined(__i386) 1813 static const uint8_t iret_insn[1] = { 0xcf }; /* iret */ 1814 #endif /* __i386 */ 1815 return (bcmp(pc, iret_insn, sizeof (iret_insn)) == 0); 1816 1817 #endif /* __xpv */ 1818 } 1819 1820 #if defined(__i386) 1821 1822 /* 1823 * Test to see if the instruction is part of __SEGREGS_POP 1824 * 1825 * Note carefully the appallingly awful dependency between 1826 * the instruction sequence used in __SEGREGS_POP and these 1827 * instructions encoded here. 1828 */ 1829 static int 1830 instr_is_segregs_pop(caddr_t pc) 1831 { 1832 static const uint8_t movw_0_esp_gs[4] = { 0x8e, 0x6c, 0x24, 0x0 }; 1833 static const uint8_t movw_4_esp_fs[4] = { 0x8e, 0x64, 0x24, 0x4 }; 1834 static const uint8_t movw_8_esp_es[4] = { 0x8e, 0x44, 0x24, 0x8 }; 1835 static const uint8_t movw_c_esp_ds[4] = { 0x8e, 0x5c, 0x24, 0xc }; 1836 1837 if (bcmp(pc, movw_0_esp_gs, sizeof (movw_0_esp_gs)) == 0 || 1838 bcmp(pc, movw_4_esp_fs, sizeof (movw_4_esp_fs)) == 0 || 1839 bcmp(pc, movw_8_esp_es, sizeof (movw_8_esp_es)) == 0 || 1840 bcmp(pc, movw_c_esp_ds, sizeof (movw_c_esp_ds)) == 0) 1841 return (1); 1842 1843 return (0); 1844 } 1845 1846 #endif /* __i386 */ 1847 1848 /* 1849 * Test to see if the instruction is part of _sys_rtt. 1850 * 1851 * Again on the hypervisor if we try to IRET to user land with a bad code 1852 * or stack selector we will get vectored through xen_failsafe_callback. 1853 * In which case we assume we got here via _sys_rtt since we only allow 1854 * IRET to user land to take place in _sys_rtt. 1855 */ 1856 static int 1857 instr_is_sys_rtt(caddr_t pc) 1858 { 1859 extern void _sys_rtt(), _sys_rtt_end(); 1860 1861 if ((uintptr_t)pc < (uintptr_t)_sys_rtt || 1862 (uintptr_t)pc > (uintptr_t)_sys_rtt_end) 1863 return (0); 1864 1865 return (1); 1866 } 1867 1868 /* 1869 * Handle #gp faults in kernel mode. 1870 * 1871 * One legitimate way this can happen is if we attempt to update segment 1872 * registers to naughty values on the way out of the kernel. 1873 * 1874 * This can happen in a couple of ways: someone - either accidentally or 1875 * on purpose - creates (setcontext(2), lwp_create(2)) or modifies 1876 * (signal(2)) a ucontext that contains silly segment register values. 1877 * Or someone - either accidentally or on purpose - modifies the prgregset_t 1878 * of a subject process via /proc to contain silly segment register values. 1879 * 1880 * (The unfortunate part is that we can end up discovering the bad segment 1881 * register value in the middle of an 'iret' after we've popped most of the 1882 * stack. So it becomes quite difficult to associate an accurate ucontext 1883 * with the lwp, because the act of taking the #gp trap overwrites most of 1884 * what we were going to send the lwp.) 1885 * 1886 * OTOH if it turns out that's -not- the problem, and we're -not- an lwp 1887 * trying to return to user mode and we get a #gp fault, then we need 1888 * to die() -- which will happen if we return non-zero from this routine. 1889 */ 1890 static int 1891 kern_gpfault(struct regs *rp) 1892 { 1893 kthread_t *t = curthread; 1894 proc_t *p = ttoproc(t); 1895 klwp_t *lwp = ttolwp(t); 1896 struct regs tmpregs, *trp = NULL; 1897 caddr_t pc = (caddr_t)rp->r_pc; 1898 int v; 1899 uint32_t auditing = AU_AUDITING(); 1900 1901 /* 1902 * if we're not an lwp, or in the case of running native the 1903 * pc range is outside _sys_rtt, then we should immediately 1904 * be die()ing horribly. 1905 */ 1906 if (lwp == NULL || !instr_is_sys_rtt(pc)) 1907 return (1); 1908 1909 /* 1910 * So at least we're in the right part of the kernel. 1911 * 1912 * Disassemble the instruction at the faulting pc. 1913 * Once we know what it is, we carefully reconstruct the stack 1914 * based on the order in which the stack is deconstructed in 1915 * _sys_rtt. Ew. 1916 */ 1917 if (instr_is_iret(pc)) { 1918 /* 1919 * We took the #gp while trying to perform the IRET. 1920 * This means that either %cs or %ss are bad. 1921 * All we know for sure is that most of the general 1922 * registers have been restored, including the 1923 * segment registers, and all we have left on the 1924 * topmost part of the lwp's stack are the 1925 * registers that the iretq was unable to consume. 1926 * 1927 * All the rest of the state was crushed by the #gp 1928 * which pushed -its- registers atop our old save area 1929 * (because we had to decrement the stack pointer, sigh) so 1930 * all that we can try and do is to reconstruct the 1931 * crushed frame from the #gp trap frame itself. 1932 */ 1933 trp = &tmpregs; 1934 trp->r_ss = lwptoregs(lwp)->r_ss; 1935 trp->r_sp = lwptoregs(lwp)->r_sp; 1936 trp->r_ps = lwptoregs(lwp)->r_ps; 1937 trp->r_cs = lwptoregs(lwp)->r_cs; 1938 trp->r_pc = lwptoregs(lwp)->r_pc; 1939 bcopy(rp, trp, offsetof(struct regs, r_pc)); 1940 1941 /* 1942 * Validate simple math 1943 */ 1944 ASSERT(trp->r_pc == lwptoregs(lwp)->r_pc); 1945 ASSERT(trp->r_err == rp->r_err); 1946 1947 1948 1949 } 1950 1951 #if defined(__amd64) 1952 if (trp == NULL && lwp->lwp_pcb.pcb_rupdate != 0) { 1953 1954 /* 1955 * This is the common case -- we're trying to load 1956 * a bad segment register value in the only section 1957 * of kernel code that ever loads segment registers. 1958 * 1959 * We don't need to do anything at this point because 1960 * the pcb contains all the pending segment register 1961 * state, and the regs are still intact because we 1962 * didn't adjust the stack pointer yet. Given the fidelity 1963 * of all this, we could conceivably send a signal 1964 * to the lwp, rather than core-ing. 1965 */ 1966 trp = lwptoregs(lwp); 1967 ASSERT((caddr_t)trp == (caddr_t)rp->r_sp); 1968 } 1969 1970 #elif defined(__i386) 1971 1972 if (trp == NULL && instr_is_segregs_pop(pc)) 1973 trp = lwptoregs(lwp); 1974 1975 #endif /* __i386 */ 1976 1977 if (trp == NULL) 1978 return (1); 1979 1980 /* 1981 * If we get to here, we're reasonably confident that we've 1982 * correctly decoded what happened on the way out of the kernel. 1983 * Rewrite the lwp's registers so that we can create a core dump 1984 * the (at least vaguely) represents the mcontext we were 1985 * being asked to restore when things went so terribly wrong. 1986 */ 1987 1988 /* 1989 * Make sure that we have a meaningful %trapno and %err. 1990 */ 1991 trp->r_trapno = rp->r_trapno; 1992 trp->r_err = rp->r_err; 1993 1994 if ((caddr_t)trp != (caddr_t)lwptoregs(lwp)) 1995 bcopy(trp, lwptoregs(lwp), sizeof (*trp)); 1996 1997 1998 mutex_enter(&p->p_lock); 1999 lwp->lwp_cursig = SIGSEGV; 2000 mutex_exit(&p->p_lock); 2001 2002 /* 2003 * Terminate all LWPs but don't discard them. If another lwp beat 2004 * us to the punch by calling exit(), evaporate now. 2005 */ 2006 proc_is_exiting(p); 2007 if (exitlwps(1) != 0) { 2008 mutex_enter(&p->p_lock); 2009 lwp_exit(); 2010 } 2011 2012 if (auditing) /* audit core dump */ 2013 audit_core_start(SIGSEGV); 2014 v = core(SIGSEGV, B_FALSE); 2015 if (auditing) /* audit core dump */ 2016 audit_core_finish(v ? CLD_KILLED : CLD_DUMPED); 2017 exit(v ? CLD_KILLED : CLD_DUMPED, SIGSEGV); 2018 return (0); 2019 } 2020 2021 /* 2022 * dump_tss() - Display the TSS structure 2023 */ 2024 2025 #if !defined(__xpv) 2026 #if defined(__amd64) 2027 2028 static void 2029 dump_tss(void) 2030 { 2031 const char tss_fmt[] = "tss.%s:\t0x%p\n"; /* Format string */ 2032 tss_t *tss = CPU->cpu_tss; 2033 2034 printf(tss_fmt, "tss_rsp0", (void *)tss->tss_rsp0); 2035 printf(tss_fmt, "tss_rsp1", (void *)tss->tss_rsp1); 2036 printf(tss_fmt, "tss_rsp2", (void *)tss->tss_rsp2); 2037 2038 printf(tss_fmt, "tss_ist1", (void *)tss->tss_ist1); 2039 printf(tss_fmt, "tss_ist2", (void *)tss->tss_ist2); 2040 printf(tss_fmt, "tss_ist3", (void *)tss->tss_ist3); 2041 printf(tss_fmt, "tss_ist4", (void *)tss->tss_ist4); 2042 printf(tss_fmt, "tss_ist5", (void *)tss->tss_ist5); 2043 printf(tss_fmt, "tss_ist6", (void *)tss->tss_ist6); 2044 printf(tss_fmt, "tss_ist7", (void *)tss->tss_ist7); 2045 } 2046 2047 #elif defined(__i386) 2048 2049 static void 2050 dump_tss(void) 2051 { 2052 const char tss_fmt[] = "tss.%s:\t0x%p\n"; /* Format string */ 2053 tss_t *tss = CPU->cpu_tss; 2054 2055 printf(tss_fmt, "tss_link", (void *)(uintptr_t)tss->tss_link); 2056 printf(tss_fmt, "tss_esp0", (void *)(uintptr_t)tss->tss_esp0); 2057 printf(tss_fmt, "tss_ss0", (void *)(uintptr_t)tss->tss_ss0); 2058 printf(tss_fmt, "tss_esp1", (void *)(uintptr_t)tss->tss_esp1); 2059 printf(tss_fmt, "tss_ss1", (void *)(uintptr_t)tss->tss_ss1); 2060 printf(tss_fmt, "tss_esp2", (void *)(uintptr_t)tss->tss_esp2); 2061 printf(tss_fmt, "tss_ss2", (void *)(uintptr_t)tss->tss_ss2); 2062 printf(tss_fmt, "tss_cr3", (void *)(uintptr_t)tss->tss_cr3); 2063 printf(tss_fmt, "tss_eip", (void *)(uintptr_t)tss->tss_eip); 2064 printf(tss_fmt, "tss_eflags", (void *)(uintptr_t)tss->tss_eflags); 2065 printf(tss_fmt, "tss_eax", (void *)(uintptr_t)tss->tss_eax); 2066 printf(tss_fmt, "tss_ebx", (void *)(uintptr_t)tss->tss_ebx); 2067 printf(tss_fmt, "tss_ecx", (void *)(uintptr_t)tss->tss_ecx); 2068 printf(tss_fmt, "tss_edx", (void *)(uintptr_t)tss->tss_edx); 2069 printf(tss_fmt, "tss_esp", (void *)(uintptr_t)tss->tss_esp); 2070 } 2071 2072 #endif /* __amd64 */ 2073 #endif /* !__xpv */ 2074 2075 #if defined(TRAPTRACE) 2076 2077 int ttrace_nrec = 10; /* number of records to dump out */ 2078 int ttrace_dump_nregs = 0; /* dump out this many records with regs too */ 2079 2080 /* 2081 * Dump out the last ttrace_nrec traptrace records on each CPU 2082 */ 2083 static void 2084 dump_ttrace(void) 2085 { 2086 trap_trace_ctl_t *ttc; 2087 trap_trace_rec_t *rec; 2088 uintptr_t current; 2089 int i, j, k; 2090 int n = NCPU; 2091 #if defined(__amd64) 2092 const char banner[] = 2093 "CPU ADDRESS TIMESTAMP TYPE VC HANDLER PC\n"; 2094 /* Define format for the CPU, ADDRESS, and TIMESTAMP fields */ 2095 const char fmt1[] = "%3d %016lx %12llx"; 2096 char data1[34]; /* length of string formatted by fmt1 + 1 */ 2097 #elif defined(__i386) 2098 const char banner[] = 2099 "CPU ADDRESS TIMESTAMP TYPE VC HANDLER PC\n"; 2100 /* Define format for the CPU, ADDRESS, and TIMESTAMP fields */ 2101 const char fmt1[] = "%3d %08lx %12llx"; 2102 char data1[26]; /* length of string formatted by fmt1 + 1 */ 2103 #endif 2104 /* Define format for the TYPE and VC fields */ 2105 const char fmt2[] = "%4s %3x"; 2106 char data2[9]; /* length of string formatted by fmt2 + 1 */ 2107 /* 2108 * Define format for the HANDLER field. Width is arbitrary, but should 2109 * be enough for common handler's names, and leave enough space for 2110 * the PC field, especially when we are in kmdb. 2111 */ 2112 const char fmt3h[] = "#%-15s"; 2113 const char fmt3p[] = "%-16p"; 2114 const char fmt3s[] = "%-16s"; 2115 char data3[17]; /* length of string formatted by fmt3* + 1 */ 2116 2117 if (ttrace_nrec == 0) 2118 return; 2119 2120 printf("\n"); 2121 printf(banner); 2122 2123 for (i = 0; i < n; i++) { 2124 ttc = &trap_trace_ctl[i]; 2125 if (ttc->ttc_first == NULL) 2126 continue; 2127 2128 current = ttc->ttc_next - sizeof (trap_trace_rec_t); 2129 for (j = 0; j < ttrace_nrec; j++) { 2130 struct sysent *sys; 2131 struct autovec *vec; 2132 extern struct av_head autovect[]; 2133 int type; 2134 ulong_t off; 2135 char *sym, *stype; 2136 2137 if (current < ttc->ttc_first) 2138 current = 2139 ttc->ttc_limit - sizeof (trap_trace_rec_t); 2140 2141 if (current == NULL) 2142 continue; 2143 2144 rec = (trap_trace_rec_t *)current; 2145 2146 if (rec->ttr_stamp == 0) 2147 break; 2148 2149 (void) snprintf(data1, sizeof (data1), fmt1, i, 2150 (uintptr_t)rec, rec->ttr_stamp); 2151 2152 switch (rec->ttr_marker) { 2153 case TT_SYSCALL: 2154 case TT_SYSENTER: 2155 case TT_SYSC: 2156 case TT_SYSC64: 2157 #if defined(__amd64) 2158 sys = &sysent32[rec->ttr_sysnum]; 2159 switch (rec->ttr_marker) { 2160 case TT_SYSC64: 2161 sys = &sysent[rec->ttr_sysnum]; 2162 /*FALLTHROUGH*/ 2163 #elif defined(__i386) 2164 sys = &sysent[rec->ttr_sysnum]; 2165 switch (rec->ttr_marker) { 2166 case TT_SYSC64: 2167 #endif 2168 case TT_SYSC: 2169 stype = "sysc"; /* syscall */ 2170 break; 2171 case TT_SYSCALL: 2172 stype = "lcal"; /* lcall */ 2173 break; 2174 case TT_SYSENTER: 2175 stype = "syse"; /* sysenter */ 2176 break; 2177 default: 2178 break; 2179 } 2180 (void) snprintf(data2, sizeof (data2), fmt2, 2181 stype, rec->ttr_sysnum); 2182 if (sys != NULL) { 2183 sym = kobj_getsymname( 2184 (uintptr_t)sys->sy_callc, 2185 &off); 2186 if (sym != NULL) { 2187 (void) snprintf(data3, 2188 sizeof (data3), fmt3s, sym); 2189 } else { 2190 (void) snprintf(data3, 2191 sizeof (data3), fmt3p, 2192 sys->sy_callc); 2193 } 2194 } else { 2195 (void) snprintf(data3, sizeof (data3), 2196 fmt3s, "unknown"); 2197 } 2198 break; 2199 2200 case TT_INTERRUPT: 2201 (void) snprintf(data2, sizeof (data2), fmt2, 2202 "intr", rec->ttr_vector); 2203 if (get_intr_handler != NULL) 2204 vec = (struct autovec *) 2205 (*get_intr_handler) 2206 (rec->ttr_cpuid, rec->ttr_vector); 2207 else 2208 vec = 2209 autovect[rec->ttr_vector].avh_link; 2210 2211 if (vec != NULL) { 2212 sym = kobj_getsymname( 2213 (uintptr_t)vec->av_vector, &off); 2214 if (sym != NULL) { 2215 (void) snprintf(data3, 2216 sizeof (data3), fmt3s, sym); 2217 } else { 2218 (void) snprintf(data3, 2219 sizeof (data3), fmt3p, 2220 vec->av_vector); 2221 } 2222 } else { 2223 (void) snprintf(data3, sizeof (data3), 2224 fmt3s, "unknown"); 2225 } 2226 break; 2227 2228 case TT_TRAP: 2229 case TT_EVENT: 2230 type = rec->ttr_regs.r_trapno; 2231 (void) snprintf(data2, sizeof (data2), fmt2, 2232 "trap", type); 2233 if (type < TRAP_TYPES) { 2234 (void) snprintf(data3, sizeof (data3), 2235 fmt3h, trap_type_mnemonic[type]); 2236 } else { 2237 switch (type) { 2238 case T_AST: 2239 (void) snprintf(data3, 2240 sizeof (data3), fmt3s, 2241 "ast"); 2242 break; 2243 default: 2244 (void) snprintf(data3, 2245 sizeof (data3), fmt3s, ""); 2246 break; 2247 } 2248 } 2249 break; 2250 2251 default: 2252 break; 2253 } 2254 2255 sym = kobj_getsymname(rec->ttr_regs.r_pc, &off); 2256 if (sym != NULL) { 2257 printf("%s %s %s %s+%lx\n", data1, data2, data3, 2258 sym, off); 2259 } else { 2260 printf("%s %s %s %lx\n", data1, data2, data3, 2261 rec->ttr_regs.r_pc); 2262 } 2263 2264 if (ttrace_dump_nregs-- > 0) { 2265 int s; 2266 2267 if (rec->ttr_marker == TT_INTERRUPT) 2268 printf( 2269 "\t\tipl %x spl %x pri %x\n", 2270 rec->ttr_ipl, 2271 rec->ttr_spl, 2272 rec->ttr_pri); 2273 2274 dumpregs(&rec->ttr_regs); 2275 2276 printf("\t%3s: %p\n\n", " ct", 2277 (void *)rec->ttr_curthread); 2278 2279 /* 2280 * print out the pc stack that we recorded 2281 * at trap time (if any) 2282 */ 2283 for (s = 0; s < rec->ttr_sdepth; s++) { 2284 uintptr_t fullpc; 2285 2286 if (s >= TTR_STACK_DEPTH) { 2287 printf("ttr_sdepth corrupt\n"); 2288 break; 2289 } 2290 2291 fullpc = (uintptr_t)rec->ttr_stack[s]; 2292 2293 sym = kobj_getsymname(fullpc, &off); 2294 if (sym != NULL) 2295 printf("-> %s+0x%lx()\n", 2296 sym, off); 2297 else 2298 printf("-> 0x%lx()\n", fullpc); 2299 } 2300 printf("\n"); 2301 } 2302 current -= sizeof (trap_trace_rec_t); 2303 } 2304 } 2305 } 2306 2307 #endif /* TRAPTRACE */ 2308 2309 void 2310 panic_showtrap(struct panic_trap_info *tip) 2311 { 2312 showregs(tip->trap_type, tip->trap_regs, tip->trap_addr); 2313 2314 #if defined(TRAPTRACE) 2315 dump_ttrace(); 2316 #endif 2317 2318 #if !defined(__xpv) 2319 if (tip->trap_type == T_DBLFLT) 2320 dump_tss(); 2321 #endif 2322 } 2323 2324 void 2325 panic_savetrap(panic_data_t *pdp, struct panic_trap_info *tip) 2326 { 2327 panic_saveregs(pdp, tip->trap_regs); 2328 } 2329