1 /* 2 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 3 * Copyright 2007-2010 Freescale Semiconductor, Inc. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License 7 * as published by the Free Software Foundation; either version 8 * 2 of the License, or (at your option) any later version. 9 * 10 * Modified by Cort Dougan (cort@cs.nmt.edu) 11 * and Paul Mackerras (paulus@samba.org) 12 */ 13 14 /* 15 * This file handles the architecture-dependent parts of hardware exceptions 16 */ 17 18 #include <linux/errno.h> 19 #include <linux/sched.h> 20 #include <linux/sched/debug.h> 21 #include <linux/kernel.h> 22 #include <linux/mm.h> 23 #include <linux/pkeys.h> 24 #include <linux/stddef.h> 25 #include <linux/unistd.h> 26 #include <linux/ptrace.h> 27 #include <linux/user.h> 28 #include <linux/interrupt.h> 29 #include <linux/init.h> 30 #include <linux/extable.h> 31 #include <linux/module.h> /* print_modules */ 32 #include <linux/prctl.h> 33 #include <linux/delay.h> 34 #include <linux/kprobes.h> 35 #include <linux/kexec.h> 36 #include <linux/backlight.h> 37 #include <linux/bug.h> 38 #include <linux/kdebug.h> 39 #include <linux/ratelimit.h> 40 #include <linux/context_tracking.h> 41 #include <linux/smp.h> 42 #include <linux/console.h> 43 #include <linux/kmsg_dump.h> 44 45 #include <asm/emulated_ops.h> 46 #include <asm/pgtable.h> 47 #include <linux/uaccess.h> 48 #include <asm/debugfs.h> 49 #include <asm/io.h> 50 #include <asm/machdep.h> 51 #include <asm/rtas.h> 52 #include <asm/pmc.h> 53 #include <asm/reg.h> 54 #ifdef CONFIG_PMAC_BACKLIGHT 55 #include <asm/backlight.h> 56 #endif 57 #ifdef CONFIG_PPC64 58 #include <asm/firmware.h> 59 #include <asm/processor.h> 60 #include <asm/tm.h> 61 #endif 62 #include <asm/kexec.h> 63 #include <asm/ppc-opcode.h> 64 #include <asm/rio.h> 65 #include <asm/fadump.h> 66 #include <asm/switch_to.h> 67 #include <asm/tm.h> 68 #include <asm/debug.h> 69 #include <asm/asm-prototypes.h> 70 #include <asm/hmi.h> 71 #include <sysdev/fsl_pci.h> 72 #include <asm/kprobes.h> 73 #include <asm/stacktrace.h> 74 75 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC_CORE) 76 int (*__debugger)(struct pt_regs *regs) __read_mostly; 77 int (*__debugger_ipi)(struct pt_regs *regs) __read_mostly; 78 int (*__debugger_bpt)(struct pt_regs *regs) __read_mostly; 79 int (*__debugger_sstep)(struct pt_regs *regs) __read_mostly; 80 int (*__debugger_iabr_match)(struct pt_regs *regs) __read_mostly; 81 int (*__debugger_break_match)(struct pt_regs *regs) __read_mostly; 82 int (*__debugger_fault_handler)(struct pt_regs *regs) __read_mostly; 83 84 EXPORT_SYMBOL(__debugger); 85 EXPORT_SYMBOL(__debugger_ipi); 86 EXPORT_SYMBOL(__debugger_bpt); 87 EXPORT_SYMBOL(__debugger_sstep); 88 EXPORT_SYMBOL(__debugger_iabr_match); 89 EXPORT_SYMBOL(__debugger_break_match); 90 EXPORT_SYMBOL(__debugger_fault_handler); 91 #endif 92 93 /* Transactional Memory trap debug */ 94 #ifdef TM_DEBUG_SW 95 #define TM_DEBUG(x...) printk(KERN_INFO x) 96 #else 97 #define TM_DEBUG(x...) do { } while(0) 98 #endif 99 100 static const char *signame(int signr) 101 { 102 switch (signr) { 103 case SIGBUS: return "bus error"; 104 case SIGFPE: return "floating point exception"; 105 case SIGILL: return "illegal instruction"; 106 case SIGSEGV: return "segfault"; 107 case SIGTRAP: return "unhandled trap"; 108 } 109 110 return "unknown signal"; 111 } 112 113 /* 114 * Trap & Exception support 115 */ 116 117 #ifdef CONFIG_PMAC_BACKLIGHT 118 static void pmac_backlight_unblank(void) 119 { 120 mutex_lock(&pmac_backlight_mutex); 121 if (pmac_backlight) { 122 struct backlight_properties *props; 123 124 props = &pmac_backlight->props; 125 props->brightness = props->max_brightness; 126 props->power = FB_BLANK_UNBLANK; 127 backlight_update_status(pmac_backlight); 128 } 129 mutex_unlock(&pmac_backlight_mutex); 130 } 131 #else 132 static inline void pmac_backlight_unblank(void) { } 133 #endif 134 135 /* 136 * If oops/die is expected to crash the machine, return true here. 137 * 138 * This should not be expected to be 100% accurate, there may be 139 * notifiers registered or other unexpected conditions that may bring 140 * down the kernel. Or if the current process in the kernel is holding 141 * locks or has other critical state, the kernel may become effectively 142 * unusable anyway. 143 */ 144 bool die_will_crash(void) 145 { 146 if (should_fadump_crash()) 147 return true; 148 if (kexec_should_crash(current)) 149 return true; 150 if (in_interrupt() || panic_on_oops || 151 !current->pid || is_global_init(current)) 152 return true; 153 154 return false; 155 } 156 157 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; 158 static int die_owner = -1; 159 static unsigned int die_nest_count; 160 static int die_counter; 161 162 extern void panic_flush_kmsg_start(void) 163 { 164 /* 165 * These are mostly taken from kernel/panic.c, but tries to do 166 * relatively minimal work. Don't use delay functions (TB may 167 * be broken), don't crash dump (need to set a firmware log), 168 * don't run notifiers. We do want to get some information to 169 * Linux console. 170 */ 171 console_verbose(); 172 bust_spinlocks(1); 173 } 174 175 extern void panic_flush_kmsg_end(void) 176 { 177 printk_safe_flush_on_panic(); 178 kmsg_dump(KMSG_DUMP_PANIC); 179 bust_spinlocks(0); 180 debug_locks_off(); 181 console_flush_on_panic(); 182 } 183 184 static unsigned long oops_begin(struct pt_regs *regs) 185 { 186 int cpu; 187 unsigned long flags; 188 189 oops_enter(); 190 191 /* racy, but better than risking deadlock. */ 192 raw_local_irq_save(flags); 193 cpu = smp_processor_id(); 194 if (!arch_spin_trylock(&die_lock)) { 195 if (cpu == die_owner) 196 /* nested oops. should stop eventually */; 197 else 198 arch_spin_lock(&die_lock); 199 } 200 die_nest_count++; 201 die_owner = cpu; 202 console_verbose(); 203 bust_spinlocks(1); 204 if (machine_is(powermac)) 205 pmac_backlight_unblank(); 206 return flags; 207 } 208 NOKPROBE_SYMBOL(oops_begin); 209 210 static void oops_end(unsigned long flags, struct pt_regs *regs, 211 int signr) 212 { 213 bust_spinlocks(0); 214 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 215 die_nest_count--; 216 oops_exit(); 217 printk("\n"); 218 if (!die_nest_count) { 219 /* Nest count reaches zero, release the lock. */ 220 die_owner = -1; 221 arch_spin_unlock(&die_lock); 222 } 223 raw_local_irq_restore(flags); 224 225 /* 226 * system_reset_excption handles debugger, crash dump, panic, for 0x100 227 */ 228 if (TRAP(regs) == 0x100) 229 return; 230 231 crash_fadump(regs, "die oops"); 232 233 if (kexec_should_crash(current)) 234 crash_kexec(regs); 235 236 if (!signr) 237 return; 238 239 /* 240 * While our oops output is serialised by a spinlock, output 241 * from panic() called below can race and corrupt it. If we 242 * know we are going to panic, delay for 1 second so we have a 243 * chance to get clean backtraces from all CPUs that are oopsing. 244 */ 245 if (in_interrupt() || panic_on_oops || !current->pid || 246 is_global_init(current)) { 247 mdelay(MSEC_PER_SEC); 248 } 249 250 if (panic_on_oops) 251 panic("Fatal exception"); 252 do_exit(signr); 253 } 254 NOKPROBE_SYMBOL(oops_end); 255 256 static int __die(const char *str, struct pt_regs *regs, long err) 257 { 258 printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); 259 260 if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN)) 261 printk("LE "); 262 else 263 printk("BE "); 264 265 if (IS_ENABLED(CONFIG_PREEMPT)) 266 pr_cont("PREEMPT "); 267 268 if (IS_ENABLED(CONFIG_SMP)) 269 pr_cont("SMP NR_CPUS=%d ", NR_CPUS); 270 271 if (debug_pagealloc_enabled()) 272 pr_cont("DEBUG_PAGEALLOC "); 273 274 if (IS_ENABLED(CONFIG_NUMA)) 275 pr_cont("NUMA "); 276 277 pr_cont("%s\n", ppc_md.name ? ppc_md.name : ""); 278 279 if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP) 280 return 1; 281 282 print_modules(); 283 show_regs(regs); 284 285 return 0; 286 } 287 NOKPROBE_SYMBOL(__die); 288 289 void die(const char *str, struct pt_regs *regs, long err) 290 { 291 unsigned long flags; 292 293 /* 294 * system_reset_excption handles debugger, crash dump, panic, for 0x100 295 */ 296 if (TRAP(regs) != 0x100) { 297 if (debugger(regs)) 298 return; 299 } 300 301 flags = oops_begin(regs); 302 if (__die(str, regs, err)) 303 err = 0; 304 oops_end(flags, regs, err); 305 } 306 NOKPROBE_SYMBOL(die); 307 308 void user_single_step_report(struct pt_regs *regs) 309 { 310 force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)regs->nip, current); 311 } 312 313 static void show_signal_msg(int signr, struct pt_regs *regs, int code, 314 unsigned long addr) 315 { 316 static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, 317 DEFAULT_RATELIMIT_BURST); 318 319 if (!show_unhandled_signals) 320 return; 321 322 if (!unhandled_signal(current, signr)) 323 return; 324 325 if (!__ratelimit(&rs)) 326 return; 327 328 pr_info("%s[%d]: %s (%d) at %lx nip %lx lr %lx code %x", 329 current->comm, current->pid, signame(signr), signr, 330 addr, regs->nip, regs->link, code); 331 332 print_vma_addr(KERN_CONT " in ", regs->nip); 333 334 pr_cont("\n"); 335 336 show_user_instructions(regs); 337 } 338 339 static bool exception_common(int signr, struct pt_regs *regs, int code, 340 unsigned long addr) 341 { 342 if (!user_mode(regs)) { 343 die("Exception in kernel mode", regs, signr); 344 return false; 345 } 346 347 show_signal_msg(signr, regs, code, addr); 348 349 if (arch_irqs_disabled() && !arch_irq_disabled_regs(regs)) 350 local_irq_enable(); 351 352 current->thread.trap_nr = code; 353 354 /* 355 * Save all the pkey registers AMR/IAMR/UAMOR. Eg: Core dumps need 356 * to capture the content, if the task gets killed. 357 */ 358 thread_pkey_regs_save(¤t->thread); 359 360 return true; 361 } 362 363 void _exception_pkey(struct pt_regs *regs, unsigned long addr, int key) 364 { 365 if (!exception_common(SIGSEGV, regs, SEGV_PKUERR, addr)) 366 return; 367 368 force_sig_pkuerr((void __user *) addr, key); 369 } 370 371 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) 372 { 373 if (!exception_common(signr, regs, code, addr)) 374 return; 375 376 force_sig_fault(signr, code, (void __user *)addr, current); 377 } 378 379 void system_reset_exception(struct pt_regs *regs) 380 { 381 /* 382 * Avoid crashes in case of nested NMI exceptions. Recoverability 383 * is determined by RI and in_nmi 384 */ 385 bool nested = in_nmi(); 386 if (!nested) 387 nmi_enter(); 388 389 __this_cpu_inc(irq_stat.sreset_irqs); 390 391 /* See if any machine dependent calls */ 392 if (ppc_md.system_reset_exception) { 393 if (ppc_md.system_reset_exception(regs)) 394 goto out; 395 } 396 397 if (debugger(regs)) 398 goto out; 399 400 /* 401 * A system reset is a request to dump, so we always send 402 * it through the crashdump code (if fadump or kdump are 403 * registered). 404 */ 405 crash_fadump(regs, "System Reset"); 406 407 crash_kexec(regs); 408 409 /* 410 * We aren't the primary crash CPU. We need to send it 411 * to a holding pattern to avoid it ending up in the panic 412 * code. 413 */ 414 crash_kexec_secondary(regs); 415 416 /* 417 * No debugger or crash dump registered, print logs then 418 * panic. 419 */ 420 die("System Reset", regs, SIGABRT); 421 422 mdelay(2*MSEC_PER_SEC); /* Wait a little while for others to print */ 423 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 424 nmi_panic(regs, "System Reset"); 425 426 out: 427 #ifdef CONFIG_PPC_BOOK3S_64 428 BUG_ON(get_paca()->in_nmi == 0); 429 if (get_paca()->in_nmi > 1) 430 nmi_panic(regs, "Unrecoverable nested System Reset"); 431 #endif 432 /* Must die if the interrupt is not recoverable */ 433 if (!(regs->msr & MSR_RI)) 434 nmi_panic(regs, "Unrecoverable System Reset"); 435 436 if (!nested) 437 nmi_exit(); 438 439 /* What should we do here? We could issue a shutdown or hard reset. */ 440 } 441 442 /* 443 * I/O accesses can cause machine checks on powermacs. 444 * Check if the NIP corresponds to the address of a sync 445 * instruction for which there is an entry in the exception 446 * table. 447 * Note that the 601 only takes a machine check on TEA 448 * (transfer error ack) signal assertion, and does not 449 * set any of the top 16 bits of SRR1. 450 * -- paulus. 451 */ 452 static inline int check_io_access(struct pt_regs *regs) 453 { 454 #ifdef CONFIG_PPC32 455 unsigned long msr = regs->msr; 456 const struct exception_table_entry *entry; 457 unsigned int *nip = (unsigned int *)regs->nip; 458 459 if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000))) 460 && (entry = search_exception_tables(regs->nip)) != NULL) { 461 /* 462 * Check that it's a sync instruction, or somewhere 463 * in the twi; isync; nop sequence that inb/inw/inl uses. 464 * As the address is in the exception table 465 * we should be able to read the instr there. 466 * For the debug message, we look at the preceding 467 * load or store. 468 */ 469 if (*nip == PPC_INST_NOP) 470 nip -= 2; 471 else if (*nip == PPC_INST_ISYNC) 472 --nip; 473 if (*nip == PPC_INST_SYNC || (*nip >> 26) == OP_TRAP) { 474 unsigned int rb; 475 476 --nip; 477 rb = (*nip >> 11) & 0x1f; 478 printk(KERN_DEBUG "%s bad port %lx at %p\n", 479 (*nip & 0x100)? "OUT to": "IN from", 480 regs->gpr[rb] - _IO_BASE, nip); 481 regs->msr |= MSR_RI; 482 regs->nip = extable_fixup(entry); 483 return 1; 484 } 485 } 486 #endif /* CONFIG_PPC32 */ 487 return 0; 488 } 489 490 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 491 /* On 4xx, the reason for the machine check or program exception 492 is in the ESR. */ 493 #define get_reason(regs) ((regs)->dsisr) 494 #define REASON_FP ESR_FP 495 #define REASON_ILLEGAL (ESR_PIL | ESR_PUO) 496 #define REASON_PRIVILEGED ESR_PPR 497 #define REASON_TRAP ESR_PTR 498 499 /* single-step stuff */ 500 #define single_stepping(regs) (current->thread.debug.dbcr0 & DBCR0_IC) 501 #define clear_single_step(regs) (current->thread.debug.dbcr0 &= ~DBCR0_IC) 502 #define clear_br_trace(regs) do {} while(0) 503 #else 504 /* On non-4xx, the reason for the machine check or program 505 exception is in the MSR. */ 506 #define get_reason(regs) ((regs)->msr) 507 #define REASON_TM SRR1_PROGTM 508 #define REASON_FP SRR1_PROGFPE 509 #define REASON_ILLEGAL SRR1_PROGILL 510 #define REASON_PRIVILEGED SRR1_PROGPRIV 511 #define REASON_TRAP SRR1_PROGTRAP 512 513 #define single_stepping(regs) ((regs)->msr & MSR_SE) 514 #define clear_single_step(regs) ((regs)->msr &= ~MSR_SE) 515 #define clear_br_trace(regs) ((regs)->msr &= ~MSR_BE) 516 #endif 517 518 #if defined(CONFIG_E500) 519 int machine_check_e500mc(struct pt_regs *regs) 520 { 521 unsigned long mcsr = mfspr(SPRN_MCSR); 522 unsigned long pvr = mfspr(SPRN_PVR); 523 unsigned long reason = mcsr; 524 int recoverable = 1; 525 526 if (reason & MCSR_LD) { 527 recoverable = fsl_rio_mcheck_exception(regs); 528 if (recoverable == 1) 529 goto silent_out; 530 } 531 532 printk("Machine check in kernel mode.\n"); 533 printk("Caused by (from MCSR=%lx): ", reason); 534 535 if (reason & MCSR_MCP) 536 pr_cont("Machine Check Signal\n"); 537 538 if (reason & MCSR_ICPERR) { 539 pr_cont("Instruction Cache Parity Error\n"); 540 541 /* 542 * This is recoverable by invalidating the i-cache. 543 */ 544 mtspr(SPRN_L1CSR1, mfspr(SPRN_L1CSR1) | L1CSR1_ICFI); 545 while (mfspr(SPRN_L1CSR1) & L1CSR1_ICFI) 546 ; 547 548 /* 549 * This will generally be accompanied by an instruction 550 * fetch error report -- only treat MCSR_IF as fatal 551 * if it wasn't due to an L1 parity error. 552 */ 553 reason &= ~MCSR_IF; 554 } 555 556 if (reason & MCSR_DCPERR_MC) { 557 pr_cont("Data Cache Parity Error\n"); 558 559 /* 560 * In write shadow mode we auto-recover from the error, but it 561 * may still get logged and cause a machine check. We should 562 * only treat the non-write shadow case as non-recoverable. 563 */ 564 /* On e6500 core, L1 DCWS (Data cache write shadow mode) bit 565 * is not implemented but L1 data cache always runs in write 566 * shadow mode. Hence on data cache parity errors HW will 567 * automatically invalidate the L1 Data Cache. 568 */ 569 if (PVR_VER(pvr) != PVR_VER_E6500) { 570 if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS)) 571 recoverable = 0; 572 } 573 } 574 575 if (reason & MCSR_L2MMU_MHIT) { 576 pr_cont("Hit on multiple TLB entries\n"); 577 recoverable = 0; 578 } 579 580 if (reason & MCSR_NMI) 581 pr_cont("Non-maskable interrupt\n"); 582 583 if (reason & MCSR_IF) { 584 pr_cont("Instruction Fetch Error Report\n"); 585 recoverable = 0; 586 } 587 588 if (reason & MCSR_LD) { 589 pr_cont("Load Error Report\n"); 590 recoverable = 0; 591 } 592 593 if (reason & MCSR_ST) { 594 pr_cont("Store Error Report\n"); 595 recoverable = 0; 596 } 597 598 if (reason & MCSR_LDG) { 599 pr_cont("Guarded Load Error Report\n"); 600 recoverable = 0; 601 } 602 603 if (reason & MCSR_TLBSYNC) 604 pr_cont("Simultaneous tlbsync operations\n"); 605 606 if (reason & MCSR_BSL2_ERR) { 607 pr_cont("Level 2 Cache Error\n"); 608 recoverable = 0; 609 } 610 611 if (reason & MCSR_MAV) { 612 u64 addr; 613 614 addr = mfspr(SPRN_MCAR); 615 addr |= (u64)mfspr(SPRN_MCARU) << 32; 616 617 pr_cont("Machine Check %s Address: %#llx\n", 618 reason & MCSR_MEA ? "Effective" : "Physical", addr); 619 } 620 621 silent_out: 622 mtspr(SPRN_MCSR, mcsr); 623 return mfspr(SPRN_MCSR) == 0 && recoverable; 624 } 625 626 int machine_check_e500(struct pt_regs *regs) 627 { 628 unsigned long reason = mfspr(SPRN_MCSR); 629 630 if (reason & MCSR_BUS_RBERR) { 631 if (fsl_rio_mcheck_exception(regs)) 632 return 1; 633 if (fsl_pci_mcheck_exception(regs)) 634 return 1; 635 } 636 637 printk("Machine check in kernel mode.\n"); 638 printk("Caused by (from MCSR=%lx): ", reason); 639 640 if (reason & MCSR_MCP) 641 pr_cont("Machine Check Signal\n"); 642 if (reason & MCSR_ICPERR) 643 pr_cont("Instruction Cache Parity Error\n"); 644 if (reason & MCSR_DCP_PERR) 645 pr_cont("Data Cache Push Parity Error\n"); 646 if (reason & MCSR_DCPERR) 647 pr_cont("Data Cache Parity Error\n"); 648 if (reason & MCSR_BUS_IAERR) 649 pr_cont("Bus - Instruction Address Error\n"); 650 if (reason & MCSR_BUS_RAERR) 651 pr_cont("Bus - Read Address Error\n"); 652 if (reason & MCSR_BUS_WAERR) 653 pr_cont("Bus - Write Address Error\n"); 654 if (reason & MCSR_BUS_IBERR) 655 pr_cont("Bus - Instruction Data Error\n"); 656 if (reason & MCSR_BUS_RBERR) 657 pr_cont("Bus - Read Data Bus Error\n"); 658 if (reason & MCSR_BUS_WBERR) 659 pr_cont("Bus - Write Data Bus Error\n"); 660 if (reason & MCSR_BUS_IPERR) 661 pr_cont("Bus - Instruction Parity Error\n"); 662 if (reason & MCSR_BUS_RPERR) 663 pr_cont("Bus - Read Parity Error\n"); 664 665 return 0; 666 } 667 668 int machine_check_generic(struct pt_regs *regs) 669 { 670 return 0; 671 } 672 #elif defined(CONFIG_E200) 673 int machine_check_e200(struct pt_regs *regs) 674 { 675 unsigned long reason = mfspr(SPRN_MCSR); 676 677 printk("Machine check in kernel mode.\n"); 678 printk("Caused by (from MCSR=%lx): ", reason); 679 680 if (reason & MCSR_MCP) 681 pr_cont("Machine Check Signal\n"); 682 if (reason & MCSR_CP_PERR) 683 pr_cont("Cache Push Parity Error\n"); 684 if (reason & MCSR_CPERR) 685 pr_cont("Cache Parity Error\n"); 686 if (reason & MCSR_EXCP_ERR) 687 pr_cont("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n"); 688 if (reason & MCSR_BUS_IRERR) 689 pr_cont("Bus - Read Bus Error on instruction fetch\n"); 690 if (reason & MCSR_BUS_DRERR) 691 pr_cont("Bus - Read Bus Error on data load\n"); 692 if (reason & MCSR_BUS_WRERR) 693 pr_cont("Bus - Write Bus Error on buffered store or cache line push\n"); 694 695 return 0; 696 } 697 #elif defined(CONFIG_PPC32) 698 int machine_check_generic(struct pt_regs *regs) 699 { 700 unsigned long reason = regs->msr; 701 702 printk("Machine check in kernel mode.\n"); 703 printk("Caused by (from SRR1=%lx): ", reason); 704 switch (reason & 0x601F0000) { 705 case 0x80000: 706 pr_cont("Machine check signal\n"); 707 break; 708 case 0: /* for 601 */ 709 case 0x40000: 710 case 0x140000: /* 7450 MSS error and TEA */ 711 pr_cont("Transfer error ack signal\n"); 712 break; 713 case 0x20000: 714 pr_cont("Data parity error signal\n"); 715 break; 716 case 0x10000: 717 pr_cont("Address parity error signal\n"); 718 break; 719 case 0x20000000: 720 pr_cont("L1 Data Cache error\n"); 721 break; 722 case 0x40000000: 723 pr_cont("L1 Instruction Cache error\n"); 724 break; 725 case 0x00100000: 726 pr_cont("L2 data cache parity error\n"); 727 break; 728 default: 729 pr_cont("Unknown values in msr\n"); 730 } 731 return 0; 732 } 733 #endif /* everything else */ 734 735 void machine_check_exception(struct pt_regs *regs) 736 { 737 int recover = 0; 738 bool nested = in_nmi(); 739 if (!nested) 740 nmi_enter(); 741 742 __this_cpu_inc(irq_stat.mce_exceptions); 743 744 add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); 745 746 /* See if any machine dependent calls. In theory, we would want 747 * to call the CPU first, and call the ppc_md. one if the CPU 748 * one returns a positive number. However there is existing code 749 * that assumes the board gets a first chance, so let's keep it 750 * that way for now and fix things later. --BenH. 751 */ 752 if (ppc_md.machine_check_exception) 753 recover = ppc_md.machine_check_exception(regs); 754 else if (cur_cpu_spec->machine_check) 755 recover = cur_cpu_spec->machine_check(regs); 756 757 if (recover > 0) 758 goto bail; 759 760 if (debugger_fault_handler(regs)) 761 goto bail; 762 763 if (check_io_access(regs)) 764 goto bail; 765 766 /* Must die if the interrupt is not recoverable */ 767 if (!(regs->msr & MSR_RI)) 768 nmi_panic(regs, "Unrecoverable Machine check"); 769 770 if (!nested) 771 nmi_exit(); 772 773 die("Machine check", regs, SIGBUS); 774 775 return; 776 777 bail: 778 if (!nested) 779 nmi_exit(); 780 } 781 782 void SMIException(struct pt_regs *regs) 783 { 784 die("System Management Interrupt", regs, SIGABRT); 785 } 786 787 #ifdef CONFIG_VSX 788 static void p9_hmi_special_emu(struct pt_regs *regs) 789 { 790 unsigned int ra, rb, t, i, sel, instr, rc; 791 const void __user *addr; 792 u8 vbuf[16], *vdst; 793 unsigned long ea, msr, msr_mask; 794 bool swap; 795 796 if (__get_user_inatomic(instr, (unsigned int __user *)regs->nip)) 797 return; 798 799 /* 800 * lxvb16x opcode: 0x7c0006d8 801 * lxvd2x opcode: 0x7c000698 802 * lxvh8x opcode: 0x7c000658 803 * lxvw4x opcode: 0x7c000618 804 */ 805 if ((instr & 0xfc00073e) != 0x7c000618) { 806 pr_devel("HMI vec emu: not vector CI %i:%s[%d] nip=%016lx" 807 " instr=%08x\n", 808 smp_processor_id(), current->comm, current->pid, 809 regs->nip, instr); 810 return; 811 } 812 813 /* Grab vector registers into the task struct */ 814 msr = regs->msr; /* Grab msr before we flush the bits */ 815 flush_vsx_to_thread(current); 816 enable_kernel_altivec(); 817 818 /* 819 * Is userspace running with a different endian (this is rare but 820 * not impossible) 821 */ 822 swap = (msr & MSR_LE) != (MSR_KERNEL & MSR_LE); 823 824 /* Decode the instruction */ 825 ra = (instr >> 16) & 0x1f; 826 rb = (instr >> 11) & 0x1f; 827 t = (instr >> 21) & 0x1f; 828 if (instr & 1) 829 vdst = (u8 *)¤t->thread.vr_state.vr[t]; 830 else 831 vdst = (u8 *)¤t->thread.fp_state.fpr[t][0]; 832 833 /* Grab the vector address */ 834 ea = regs->gpr[rb] + (ra ? regs->gpr[ra] : 0); 835 if (is_32bit_task()) 836 ea &= 0xfffffffful; 837 addr = (__force const void __user *)ea; 838 839 /* Check it */ 840 if (!access_ok(VERIFY_READ, addr, 16)) { 841 pr_devel("HMI vec emu: bad access %i:%s[%d] nip=%016lx" 842 " instr=%08x addr=%016lx\n", 843 smp_processor_id(), current->comm, current->pid, 844 regs->nip, instr, (unsigned long)addr); 845 return; 846 } 847 848 /* Read the vector */ 849 rc = 0; 850 if ((unsigned long)addr & 0xfUL) 851 /* unaligned case */ 852 rc = __copy_from_user_inatomic(vbuf, addr, 16); 853 else 854 __get_user_atomic_128_aligned(vbuf, addr, rc); 855 if (rc) { 856 pr_devel("HMI vec emu: page fault %i:%s[%d] nip=%016lx" 857 " instr=%08x addr=%016lx\n", 858 smp_processor_id(), current->comm, current->pid, 859 regs->nip, instr, (unsigned long)addr); 860 return; 861 } 862 863 pr_devel("HMI vec emu: emulated vector CI %i:%s[%d] nip=%016lx" 864 " instr=%08x addr=%016lx\n", 865 smp_processor_id(), current->comm, current->pid, regs->nip, 866 instr, (unsigned long) addr); 867 868 /* Grab instruction "selector" */ 869 sel = (instr >> 6) & 3; 870 871 /* 872 * Check to make sure the facility is actually enabled. This 873 * could happen if we get a false positive hit. 874 * 875 * lxvd2x/lxvw4x always check MSR VSX sel = 0,2 876 * lxvh8x/lxvb16x check MSR VSX or VEC depending on VSR used sel = 1,3 877 */ 878 msr_mask = MSR_VSX; 879 if ((sel & 1) && (instr & 1)) /* lxvh8x & lxvb16x + VSR >= 32 */ 880 msr_mask = MSR_VEC; 881 if (!(msr & msr_mask)) { 882 pr_devel("HMI vec emu: MSR fac clear %i:%s[%d] nip=%016lx" 883 " instr=%08x msr:%016lx\n", 884 smp_processor_id(), current->comm, current->pid, 885 regs->nip, instr, msr); 886 return; 887 } 888 889 /* Do logging here before we modify sel based on endian */ 890 switch (sel) { 891 case 0: /* lxvw4x */ 892 PPC_WARN_EMULATED(lxvw4x, regs); 893 break; 894 case 1: /* lxvh8x */ 895 PPC_WARN_EMULATED(lxvh8x, regs); 896 break; 897 case 2: /* lxvd2x */ 898 PPC_WARN_EMULATED(lxvd2x, regs); 899 break; 900 case 3: /* lxvb16x */ 901 PPC_WARN_EMULATED(lxvb16x, regs); 902 break; 903 } 904 905 #ifdef __LITTLE_ENDIAN__ 906 /* 907 * An LE kernel stores the vector in the task struct as an LE 908 * byte array (effectively swapping both the components and 909 * the content of the components). Those instructions expect 910 * the components to remain in ascending address order, so we 911 * swap them back. 912 * 913 * If we are running a BE user space, the expectation is that 914 * of a simple memcpy, so forcing the emulation to look like 915 * a lxvb16x should do the trick. 916 */ 917 if (swap) 918 sel = 3; 919 920 switch (sel) { 921 case 0: /* lxvw4x */ 922 for (i = 0; i < 4; i++) 923 ((u32 *)vdst)[i] = ((u32 *)vbuf)[3-i]; 924 break; 925 case 1: /* lxvh8x */ 926 for (i = 0; i < 8; i++) 927 ((u16 *)vdst)[i] = ((u16 *)vbuf)[7-i]; 928 break; 929 case 2: /* lxvd2x */ 930 for (i = 0; i < 2; i++) 931 ((u64 *)vdst)[i] = ((u64 *)vbuf)[1-i]; 932 break; 933 case 3: /* lxvb16x */ 934 for (i = 0; i < 16; i++) 935 vdst[i] = vbuf[15-i]; 936 break; 937 } 938 #else /* __LITTLE_ENDIAN__ */ 939 /* On a big endian kernel, a BE userspace only needs a memcpy */ 940 if (!swap) 941 sel = 3; 942 943 /* Otherwise, we need to swap the content of the components */ 944 switch (sel) { 945 case 0: /* lxvw4x */ 946 for (i = 0; i < 4; i++) 947 ((u32 *)vdst)[i] = cpu_to_le32(((u32 *)vbuf)[i]); 948 break; 949 case 1: /* lxvh8x */ 950 for (i = 0; i < 8; i++) 951 ((u16 *)vdst)[i] = cpu_to_le16(((u16 *)vbuf)[i]); 952 break; 953 case 2: /* lxvd2x */ 954 for (i = 0; i < 2; i++) 955 ((u64 *)vdst)[i] = cpu_to_le64(((u64 *)vbuf)[i]); 956 break; 957 case 3: /* lxvb16x */ 958 memcpy(vdst, vbuf, 16); 959 break; 960 } 961 #endif /* !__LITTLE_ENDIAN__ */ 962 963 /* Go to next instruction */ 964 regs->nip += 4; 965 } 966 #endif /* CONFIG_VSX */ 967 968 void handle_hmi_exception(struct pt_regs *regs) 969 { 970 struct pt_regs *old_regs; 971 972 old_regs = set_irq_regs(regs); 973 irq_enter(); 974 975 #ifdef CONFIG_VSX 976 /* Real mode flagged P9 special emu is needed */ 977 if (local_paca->hmi_p9_special_emu) { 978 local_paca->hmi_p9_special_emu = 0; 979 980 /* 981 * We don't want to take page faults while doing the 982 * emulation, we just replay the instruction if necessary. 983 */ 984 pagefault_disable(); 985 p9_hmi_special_emu(regs); 986 pagefault_enable(); 987 } 988 #endif /* CONFIG_VSX */ 989 990 if (ppc_md.handle_hmi_exception) 991 ppc_md.handle_hmi_exception(regs); 992 993 irq_exit(); 994 set_irq_regs(old_regs); 995 } 996 997 void unknown_exception(struct pt_regs *regs) 998 { 999 enum ctx_state prev_state = exception_enter(); 1000 1001 printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", 1002 regs->nip, regs->msr, regs->trap); 1003 1004 _exception(SIGTRAP, regs, TRAP_UNK, 0); 1005 1006 exception_exit(prev_state); 1007 } 1008 1009 void instruction_breakpoint_exception(struct pt_regs *regs) 1010 { 1011 enum ctx_state prev_state = exception_enter(); 1012 1013 if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5, 1014 5, SIGTRAP) == NOTIFY_STOP) 1015 goto bail; 1016 if (debugger_iabr_match(regs)) 1017 goto bail; 1018 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip); 1019 1020 bail: 1021 exception_exit(prev_state); 1022 } 1023 1024 void RunModeException(struct pt_regs *regs) 1025 { 1026 _exception(SIGTRAP, regs, TRAP_UNK, 0); 1027 } 1028 1029 void single_step_exception(struct pt_regs *regs) 1030 { 1031 enum ctx_state prev_state = exception_enter(); 1032 1033 clear_single_step(regs); 1034 clear_br_trace(regs); 1035 1036 if (kprobe_post_handler(regs)) 1037 return; 1038 1039 if (notify_die(DIE_SSTEP, "single_step", regs, 5, 1040 5, SIGTRAP) == NOTIFY_STOP) 1041 goto bail; 1042 if (debugger_sstep(regs)) 1043 goto bail; 1044 1045 _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip); 1046 1047 bail: 1048 exception_exit(prev_state); 1049 } 1050 NOKPROBE_SYMBOL(single_step_exception); 1051 1052 /* 1053 * After we have successfully emulated an instruction, we have to 1054 * check if the instruction was being single-stepped, and if so, 1055 * pretend we got a single-step exception. This was pointed out 1056 * by Kumar Gala. -- paulus 1057 */ 1058 static void emulate_single_step(struct pt_regs *regs) 1059 { 1060 if (single_stepping(regs)) 1061 single_step_exception(regs); 1062 } 1063 1064 static inline int __parse_fpscr(unsigned long fpscr) 1065 { 1066 int ret = FPE_FLTUNK; 1067 1068 /* Invalid operation */ 1069 if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX)) 1070 ret = FPE_FLTINV; 1071 1072 /* Overflow */ 1073 else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX)) 1074 ret = FPE_FLTOVF; 1075 1076 /* Underflow */ 1077 else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX)) 1078 ret = FPE_FLTUND; 1079 1080 /* Divide by zero */ 1081 else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX)) 1082 ret = FPE_FLTDIV; 1083 1084 /* Inexact result */ 1085 else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX)) 1086 ret = FPE_FLTRES; 1087 1088 return ret; 1089 } 1090 1091 static void parse_fpe(struct pt_regs *regs) 1092 { 1093 int code = 0; 1094 1095 flush_fp_to_thread(current); 1096 1097 code = __parse_fpscr(current->thread.fp_state.fpscr); 1098 1099 _exception(SIGFPE, regs, code, regs->nip); 1100 } 1101 1102 /* 1103 * Illegal instruction emulation support. Originally written to 1104 * provide the PVR to user applications using the mfspr rd, PVR. 1105 * Return non-zero if we can't emulate, or -EFAULT if the associated 1106 * memory access caused an access fault. Return zero on success. 1107 * 1108 * There are a couple of ways to do this, either "decode" the instruction 1109 * or directly match lots of bits. In this case, matching lots of 1110 * bits is faster and easier. 1111 * 1112 */ 1113 static int emulate_string_inst(struct pt_regs *regs, u32 instword) 1114 { 1115 u8 rT = (instword >> 21) & 0x1f; 1116 u8 rA = (instword >> 16) & 0x1f; 1117 u8 NB_RB = (instword >> 11) & 0x1f; 1118 u32 num_bytes; 1119 unsigned long EA; 1120 int pos = 0; 1121 1122 /* Early out if we are an invalid form of lswx */ 1123 if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX) 1124 if ((rT == rA) || (rT == NB_RB)) 1125 return -EINVAL; 1126 1127 EA = (rA == 0) ? 0 : regs->gpr[rA]; 1128 1129 switch (instword & PPC_INST_STRING_MASK) { 1130 case PPC_INST_LSWX: 1131 case PPC_INST_STSWX: 1132 EA += NB_RB; 1133 num_bytes = regs->xer & 0x7f; 1134 break; 1135 case PPC_INST_LSWI: 1136 case PPC_INST_STSWI: 1137 num_bytes = (NB_RB == 0) ? 32 : NB_RB; 1138 break; 1139 default: 1140 return -EINVAL; 1141 } 1142 1143 while (num_bytes != 0) 1144 { 1145 u8 val; 1146 u32 shift = 8 * (3 - (pos & 0x3)); 1147 1148 /* if process is 32-bit, clear upper 32 bits of EA */ 1149 if ((regs->msr & MSR_64BIT) == 0) 1150 EA &= 0xFFFFFFFF; 1151 1152 switch ((instword & PPC_INST_STRING_MASK)) { 1153 case PPC_INST_LSWX: 1154 case PPC_INST_LSWI: 1155 if (get_user(val, (u8 __user *)EA)) 1156 return -EFAULT; 1157 /* first time updating this reg, 1158 * zero it out */ 1159 if (pos == 0) 1160 regs->gpr[rT] = 0; 1161 regs->gpr[rT] |= val << shift; 1162 break; 1163 case PPC_INST_STSWI: 1164 case PPC_INST_STSWX: 1165 val = regs->gpr[rT] >> shift; 1166 if (put_user(val, (u8 __user *)EA)) 1167 return -EFAULT; 1168 break; 1169 } 1170 /* move EA to next address */ 1171 EA += 1; 1172 num_bytes--; 1173 1174 /* manage our position within the register */ 1175 if (++pos == 4) { 1176 pos = 0; 1177 if (++rT == 32) 1178 rT = 0; 1179 } 1180 } 1181 1182 return 0; 1183 } 1184 1185 static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword) 1186 { 1187 u32 ra,rs; 1188 unsigned long tmp; 1189 1190 ra = (instword >> 16) & 0x1f; 1191 rs = (instword >> 21) & 0x1f; 1192 1193 tmp = regs->gpr[rs]; 1194 tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL); 1195 tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL); 1196 tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL; 1197 regs->gpr[ra] = tmp; 1198 1199 return 0; 1200 } 1201 1202 static int emulate_isel(struct pt_regs *regs, u32 instword) 1203 { 1204 u8 rT = (instword >> 21) & 0x1f; 1205 u8 rA = (instword >> 16) & 0x1f; 1206 u8 rB = (instword >> 11) & 0x1f; 1207 u8 BC = (instword >> 6) & 0x1f; 1208 u8 bit; 1209 unsigned long tmp; 1210 1211 tmp = (rA == 0) ? 0 : regs->gpr[rA]; 1212 bit = (regs->ccr >> (31 - BC)) & 0x1; 1213 1214 regs->gpr[rT] = bit ? tmp : regs->gpr[rB]; 1215 1216 return 0; 1217 } 1218 1219 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1220 static inline bool tm_abort_check(struct pt_regs *regs, int cause) 1221 { 1222 /* If we're emulating a load/store in an active transaction, we cannot 1223 * emulate it as the kernel operates in transaction suspended context. 1224 * We need to abort the transaction. This creates a persistent TM 1225 * abort so tell the user what caused it with a new code. 1226 */ 1227 if (MSR_TM_TRANSACTIONAL(regs->msr)) { 1228 tm_enable(); 1229 tm_abort(cause); 1230 return true; 1231 } 1232 return false; 1233 } 1234 #else 1235 static inline bool tm_abort_check(struct pt_regs *regs, int reason) 1236 { 1237 return false; 1238 } 1239 #endif 1240 1241 static int emulate_instruction(struct pt_regs *regs) 1242 { 1243 u32 instword; 1244 u32 rd; 1245 1246 if (!user_mode(regs)) 1247 return -EINVAL; 1248 CHECK_FULL_REGS(regs); 1249 1250 if (get_user(instword, (u32 __user *)(regs->nip))) 1251 return -EFAULT; 1252 1253 /* Emulate the mfspr rD, PVR. */ 1254 if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) { 1255 PPC_WARN_EMULATED(mfpvr, regs); 1256 rd = (instword >> 21) & 0x1f; 1257 regs->gpr[rd] = mfspr(SPRN_PVR); 1258 return 0; 1259 } 1260 1261 /* Emulating the dcba insn is just a no-op. */ 1262 if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) { 1263 PPC_WARN_EMULATED(dcba, regs); 1264 return 0; 1265 } 1266 1267 /* Emulate the mcrxr insn. */ 1268 if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) { 1269 int shift = (instword >> 21) & 0x1c; 1270 unsigned long msk = 0xf0000000UL >> shift; 1271 1272 PPC_WARN_EMULATED(mcrxr, regs); 1273 regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk); 1274 regs->xer &= ~0xf0000000UL; 1275 return 0; 1276 } 1277 1278 /* Emulate load/store string insn. */ 1279 if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) { 1280 if (tm_abort_check(regs, 1281 TM_CAUSE_EMULATE | TM_CAUSE_PERSISTENT)) 1282 return -EINVAL; 1283 PPC_WARN_EMULATED(string, regs); 1284 return emulate_string_inst(regs, instword); 1285 } 1286 1287 /* Emulate the popcntb (Population Count Bytes) instruction. */ 1288 if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) { 1289 PPC_WARN_EMULATED(popcntb, regs); 1290 return emulate_popcntb_inst(regs, instword); 1291 } 1292 1293 /* Emulate isel (Integer Select) instruction */ 1294 if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) { 1295 PPC_WARN_EMULATED(isel, regs); 1296 return emulate_isel(regs, instword); 1297 } 1298 1299 /* Emulate sync instruction variants */ 1300 if ((instword & PPC_INST_SYNC_MASK) == PPC_INST_SYNC) { 1301 PPC_WARN_EMULATED(sync, regs); 1302 asm volatile("sync"); 1303 return 0; 1304 } 1305 1306 #ifdef CONFIG_PPC64 1307 /* Emulate the mfspr rD, DSCR. */ 1308 if ((((instword & PPC_INST_MFSPR_DSCR_USER_MASK) == 1309 PPC_INST_MFSPR_DSCR_USER) || 1310 ((instword & PPC_INST_MFSPR_DSCR_MASK) == 1311 PPC_INST_MFSPR_DSCR)) && 1312 cpu_has_feature(CPU_FTR_DSCR)) { 1313 PPC_WARN_EMULATED(mfdscr, regs); 1314 rd = (instword >> 21) & 0x1f; 1315 regs->gpr[rd] = mfspr(SPRN_DSCR); 1316 return 0; 1317 } 1318 /* Emulate the mtspr DSCR, rD. */ 1319 if ((((instword & PPC_INST_MTSPR_DSCR_USER_MASK) == 1320 PPC_INST_MTSPR_DSCR_USER) || 1321 ((instword & PPC_INST_MTSPR_DSCR_MASK) == 1322 PPC_INST_MTSPR_DSCR)) && 1323 cpu_has_feature(CPU_FTR_DSCR)) { 1324 PPC_WARN_EMULATED(mtdscr, regs); 1325 rd = (instword >> 21) & 0x1f; 1326 current->thread.dscr = regs->gpr[rd]; 1327 current->thread.dscr_inherit = 1; 1328 mtspr(SPRN_DSCR, current->thread.dscr); 1329 return 0; 1330 } 1331 #endif 1332 1333 return -EINVAL; 1334 } 1335 1336 int is_valid_bugaddr(unsigned long addr) 1337 { 1338 return is_kernel_addr(addr); 1339 } 1340 1341 #ifdef CONFIG_MATH_EMULATION 1342 static int emulate_math(struct pt_regs *regs) 1343 { 1344 int ret; 1345 extern int do_mathemu(struct pt_regs *regs); 1346 1347 ret = do_mathemu(regs); 1348 if (ret >= 0) 1349 PPC_WARN_EMULATED(math, regs); 1350 1351 switch (ret) { 1352 case 0: 1353 emulate_single_step(regs); 1354 return 0; 1355 case 1: { 1356 int code = 0; 1357 code = __parse_fpscr(current->thread.fp_state.fpscr); 1358 _exception(SIGFPE, regs, code, regs->nip); 1359 return 0; 1360 } 1361 case -EFAULT: 1362 _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); 1363 return 0; 1364 } 1365 1366 return -1; 1367 } 1368 #else 1369 static inline int emulate_math(struct pt_regs *regs) { return -1; } 1370 #endif 1371 1372 void program_check_exception(struct pt_regs *regs) 1373 { 1374 enum ctx_state prev_state = exception_enter(); 1375 unsigned int reason = get_reason(regs); 1376 1377 /* We can now get here via a FP Unavailable exception if the core 1378 * has no FPU, in that case the reason flags will be 0 */ 1379 1380 if (reason & REASON_FP) { 1381 /* IEEE FP exception */ 1382 parse_fpe(regs); 1383 goto bail; 1384 } 1385 if (reason & REASON_TRAP) { 1386 unsigned long bugaddr; 1387 /* Debugger is first in line to stop recursive faults in 1388 * rcu_lock, notify_die, or atomic_notifier_call_chain */ 1389 if (debugger_bpt(regs)) 1390 goto bail; 1391 1392 if (kprobe_handler(regs)) 1393 goto bail; 1394 1395 /* trap exception */ 1396 if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP) 1397 == NOTIFY_STOP) 1398 goto bail; 1399 1400 bugaddr = regs->nip; 1401 /* 1402 * Fixup bugaddr for BUG_ON() in real mode 1403 */ 1404 if (!is_kernel_addr(bugaddr) && !(regs->msr & MSR_IR)) 1405 bugaddr += PAGE_OFFSET; 1406 1407 if (!(regs->msr & MSR_PR) && /* not user-mode */ 1408 report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) { 1409 regs->nip += 4; 1410 goto bail; 1411 } 1412 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip); 1413 goto bail; 1414 } 1415 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1416 if (reason & REASON_TM) { 1417 /* This is a TM "Bad Thing Exception" program check. 1418 * This occurs when: 1419 * - An rfid/hrfid/mtmsrd attempts to cause an illegal 1420 * transition in TM states. 1421 * - A trechkpt is attempted when transactional. 1422 * - A treclaim is attempted when non transactional. 1423 * - A tend is illegally attempted. 1424 * - writing a TM SPR when transactional. 1425 * 1426 * If usermode caused this, it's done something illegal and 1427 * gets a SIGILL slap on the wrist. We call it an illegal 1428 * operand to distinguish from the instruction just being bad 1429 * (e.g. executing a 'tend' on a CPU without TM!); it's an 1430 * illegal /placement/ of a valid instruction. 1431 */ 1432 if (user_mode(regs)) { 1433 _exception(SIGILL, regs, ILL_ILLOPN, regs->nip); 1434 goto bail; 1435 } else { 1436 printk(KERN_EMERG "Unexpected TM Bad Thing exception " 1437 "at %lx (msr 0x%lx)\n", regs->nip, regs->msr); 1438 die("Unrecoverable exception", regs, SIGABRT); 1439 } 1440 } 1441 #endif 1442 1443 /* 1444 * If we took the program check in the kernel skip down to sending a 1445 * SIGILL. The subsequent cases all relate to emulating instructions 1446 * which we should only do for userspace. We also do not want to enable 1447 * interrupts for kernel faults because that might lead to further 1448 * faults, and loose the context of the original exception. 1449 */ 1450 if (!user_mode(regs)) 1451 goto sigill; 1452 1453 /* We restore the interrupt state now */ 1454 if (!arch_irq_disabled_regs(regs)) 1455 local_irq_enable(); 1456 1457 /* (reason & REASON_ILLEGAL) would be the obvious thing here, 1458 * but there seems to be a hardware bug on the 405GP (RevD) 1459 * that means ESR is sometimes set incorrectly - either to 1460 * ESR_DST (!?) or 0. In the process of chasing this with the 1461 * hardware people - not sure if it can happen on any illegal 1462 * instruction or only on FP instructions, whether there is a 1463 * pattern to occurrences etc. -dgibson 31/Mar/2003 1464 */ 1465 if (!emulate_math(regs)) 1466 goto bail; 1467 1468 /* Try to emulate it if we should. */ 1469 if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) { 1470 switch (emulate_instruction(regs)) { 1471 case 0: 1472 regs->nip += 4; 1473 emulate_single_step(regs); 1474 goto bail; 1475 case -EFAULT: 1476 _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); 1477 goto bail; 1478 } 1479 } 1480 1481 sigill: 1482 if (reason & REASON_PRIVILEGED) 1483 _exception(SIGILL, regs, ILL_PRVOPC, regs->nip); 1484 else 1485 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); 1486 1487 bail: 1488 exception_exit(prev_state); 1489 } 1490 NOKPROBE_SYMBOL(program_check_exception); 1491 1492 /* 1493 * This occurs when running in hypervisor mode on POWER6 or later 1494 * and an illegal instruction is encountered. 1495 */ 1496 void emulation_assist_interrupt(struct pt_regs *regs) 1497 { 1498 regs->msr |= REASON_ILLEGAL; 1499 program_check_exception(regs); 1500 } 1501 NOKPROBE_SYMBOL(emulation_assist_interrupt); 1502 1503 void alignment_exception(struct pt_regs *regs) 1504 { 1505 enum ctx_state prev_state = exception_enter(); 1506 int sig, code, fixed = 0; 1507 1508 /* We restore the interrupt state now */ 1509 if (!arch_irq_disabled_regs(regs)) 1510 local_irq_enable(); 1511 1512 if (tm_abort_check(regs, TM_CAUSE_ALIGNMENT | TM_CAUSE_PERSISTENT)) 1513 goto bail; 1514 1515 /* we don't implement logging of alignment exceptions */ 1516 if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS)) 1517 fixed = fix_alignment(regs); 1518 1519 if (fixed == 1) { 1520 regs->nip += 4; /* skip over emulated instruction */ 1521 emulate_single_step(regs); 1522 goto bail; 1523 } 1524 1525 /* Operand address was bad */ 1526 if (fixed == -EFAULT) { 1527 sig = SIGSEGV; 1528 code = SEGV_ACCERR; 1529 } else { 1530 sig = SIGBUS; 1531 code = BUS_ADRALN; 1532 } 1533 if (user_mode(regs)) 1534 _exception(sig, regs, code, regs->dar); 1535 else 1536 bad_page_fault(regs, regs->dar, sig); 1537 1538 bail: 1539 exception_exit(prev_state); 1540 } 1541 1542 void StackOverflow(struct pt_regs *regs) 1543 { 1544 printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n", 1545 current, regs->gpr[1]); 1546 debugger(regs); 1547 show_regs(regs); 1548 panic("kernel stack overflow"); 1549 } 1550 1551 void kernel_fp_unavailable_exception(struct pt_regs *regs) 1552 { 1553 enum ctx_state prev_state = exception_enter(); 1554 1555 printk(KERN_EMERG "Unrecoverable FP Unavailable Exception " 1556 "%lx at %lx\n", regs->trap, regs->nip); 1557 die("Unrecoverable FP Unavailable Exception", regs, SIGABRT); 1558 1559 exception_exit(prev_state); 1560 } 1561 1562 void altivec_unavailable_exception(struct pt_regs *regs) 1563 { 1564 enum ctx_state prev_state = exception_enter(); 1565 1566 if (user_mode(regs)) { 1567 /* A user program has executed an altivec instruction, 1568 but this kernel doesn't support altivec. */ 1569 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); 1570 goto bail; 1571 } 1572 1573 printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception " 1574 "%lx at %lx\n", regs->trap, regs->nip); 1575 die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT); 1576 1577 bail: 1578 exception_exit(prev_state); 1579 } 1580 1581 void vsx_unavailable_exception(struct pt_regs *regs) 1582 { 1583 if (user_mode(regs)) { 1584 /* A user program has executed an vsx instruction, 1585 but this kernel doesn't support vsx. */ 1586 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); 1587 return; 1588 } 1589 1590 printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception " 1591 "%lx at %lx\n", regs->trap, regs->nip); 1592 die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT); 1593 } 1594 1595 #ifdef CONFIG_PPC64 1596 static void tm_unavailable(struct pt_regs *regs) 1597 { 1598 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1599 if (user_mode(regs)) { 1600 current->thread.load_tm++; 1601 regs->msr |= MSR_TM; 1602 tm_enable(); 1603 tm_restore_sprs(¤t->thread); 1604 return; 1605 } 1606 #endif 1607 pr_emerg("Unrecoverable TM Unavailable Exception " 1608 "%lx at %lx\n", regs->trap, regs->nip); 1609 die("Unrecoverable TM Unavailable Exception", regs, SIGABRT); 1610 } 1611 1612 void facility_unavailable_exception(struct pt_regs *regs) 1613 { 1614 static char *facility_strings[] = { 1615 [FSCR_FP_LG] = "FPU", 1616 [FSCR_VECVSX_LG] = "VMX/VSX", 1617 [FSCR_DSCR_LG] = "DSCR", 1618 [FSCR_PM_LG] = "PMU SPRs", 1619 [FSCR_BHRB_LG] = "BHRB", 1620 [FSCR_TM_LG] = "TM", 1621 [FSCR_EBB_LG] = "EBB", 1622 [FSCR_TAR_LG] = "TAR", 1623 [FSCR_MSGP_LG] = "MSGP", 1624 [FSCR_SCV_LG] = "SCV", 1625 }; 1626 char *facility = "unknown"; 1627 u64 value; 1628 u32 instword, rd; 1629 u8 status; 1630 bool hv; 1631 1632 hv = (TRAP(regs) == 0xf80); 1633 if (hv) 1634 value = mfspr(SPRN_HFSCR); 1635 else 1636 value = mfspr(SPRN_FSCR); 1637 1638 status = value >> 56; 1639 if ((hv || status >= 2) && 1640 (status < ARRAY_SIZE(facility_strings)) && 1641 facility_strings[status]) 1642 facility = facility_strings[status]; 1643 1644 /* We should not have taken this interrupt in kernel */ 1645 if (!user_mode(regs)) { 1646 pr_emerg("Facility '%s' unavailable (%d) exception in kernel mode at %lx\n", 1647 facility, status, regs->nip); 1648 die("Unexpected facility unavailable exception", regs, SIGABRT); 1649 } 1650 1651 /* We restore the interrupt state now */ 1652 if (!arch_irq_disabled_regs(regs)) 1653 local_irq_enable(); 1654 1655 if (status == FSCR_DSCR_LG) { 1656 /* 1657 * User is accessing the DSCR register using the problem 1658 * state only SPR number (0x03) either through a mfspr or 1659 * a mtspr instruction. If it is a write attempt through 1660 * a mtspr, then we set the inherit bit. This also allows 1661 * the user to write or read the register directly in the 1662 * future by setting via the FSCR DSCR bit. But in case it 1663 * is a read DSCR attempt through a mfspr instruction, we 1664 * just emulate the instruction instead. This code path will 1665 * always emulate all the mfspr instructions till the user 1666 * has attempted at least one mtspr instruction. This way it 1667 * preserves the same behaviour when the user is accessing 1668 * the DSCR through privilege level only SPR number (0x11) 1669 * which is emulated through illegal instruction exception. 1670 * We always leave HFSCR DSCR set. 1671 */ 1672 if (get_user(instword, (u32 __user *)(regs->nip))) { 1673 pr_err("Failed to fetch the user instruction\n"); 1674 return; 1675 } 1676 1677 /* Write into DSCR (mtspr 0x03, RS) */ 1678 if ((instword & PPC_INST_MTSPR_DSCR_USER_MASK) 1679 == PPC_INST_MTSPR_DSCR_USER) { 1680 rd = (instword >> 21) & 0x1f; 1681 current->thread.dscr = regs->gpr[rd]; 1682 current->thread.dscr_inherit = 1; 1683 current->thread.fscr |= FSCR_DSCR; 1684 mtspr(SPRN_FSCR, current->thread.fscr); 1685 } 1686 1687 /* Read from DSCR (mfspr RT, 0x03) */ 1688 if ((instword & PPC_INST_MFSPR_DSCR_USER_MASK) 1689 == PPC_INST_MFSPR_DSCR_USER) { 1690 if (emulate_instruction(regs)) { 1691 pr_err("DSCR based mfspr emulation failed\n"); 1692 return; 1693 } 1694 regs->nip += 4; 1695 emulate_single_step(regs); 1696 } 1697 return; 1698 } 1699 1700 if (status == FSCR_TM_LG) { 1701 /* 1702 * If we're here then the hardware is TM aware because it 1703 * generated an exception with FSRM_TM set. 1704 * 1705 * If cpu_has_feature(CPU_FTR_TM) is false, then either firmware 1706 * told us not to do TM, or the kernel is not built with TM 1707 * support. 1708 * 1709 * If both of those things are true, then userspace can spam the 1710 * console by triggering the printk() below just by continually 1711 * doing tbegin (or any TM instruction). So in that case just 1712 * send the process a SIGILL immediately. 1713 */ 1714 if (!cpu_has_feature(CPU_FTR_TM)) 1715 goto out; 1716 1717 tm_unavailable(regs); 1718 return; 1719 } 1720 1721 pr_err_ratelimited("%sFacility '%s' unavailable (%d), exception at 0x%lx, MSR=%lx\n", 1722 hv ? "Hypervisor " : "", facility, status, regs->nip, regs->msr); 1723 1724 out: 1725 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); 1726 } 1727 #endif 1728 1729 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1730 1731 void fp_unavailable_tm(struct pt_regs *regs) 1732 { 1733 /* Note: This does not handle any kind of FP laziness. */ 1734 1735 TM_DEBUG("FP Unavailable trap whilst transactional at 0x%lx, MSR=%lx\n", 1736 regs->nip, regs->msr); 1737 1738 /* We can only have got here if the task started using FP after 1739 * beginning the transaction. So, the transactional regs are just a 1740 * copy of the checkpointed ones. But, we still need to recheckpoint 1741 * as we're enabling FP for the process; it will return, abort the 1742 * transaction, and probably retry but now with FP enabled. So the 1743 * checkpointed FP registers need to be loaded. 1744 */ 1745 tm_reclaim_current(TM_CAUSE_FAC_UNAV); 1746 1747 /* 1748 * Reclaim initially saved out bogus (lazy) FPRs to ckfp_state, and 1749 * then it was overwrite by the thr->fp_state by tm_reclaim_thread(). 1750 * 1751 * At this point, ck{fp,vr}_state contains the exact values we want to 1752 * recheckpoint. 1753 */ 1754 1755 /* Enable FP for the task: */ 1756 current->thread.load_fp = 1; 1757 1758 /* 1759 * Recheckpoint all the checkpointed ckpt, ck{fp, vr}_state registers. 1760 */ 1761 tm_recheckpoint(¤t->thread); 1762 } 1763 1764 void altivec_unavailable_tm(struct pt_regs *regs) 1765 { 1766 /* See the comments in fp_unavailable_tm(). This function operates 1767 * the same way. 1768 */ 1769 1770 TM_DEBUG("Vector Unavailable trap whilst transactional at 0x%lx," 1771 "MSR=%lx\n", 1772 regs->nip, regs->msr); 1773 tm_reclaim_current(TM_CAUSE_FAC_UNAV); 1774 current->thread.load_vec = 1; 1775 tm_recheckpoint(¤t->thread); 1776 current->thread.used_vr = 1; 1777 } 1778 1779 void vsx_unavailable_tm(struct pt_regs *regs) 1780 { 1781 /* See the comments in fp_unavailable_tm(). This works similarly, 1782 * though we're loading both FP and VEC registers in here. 1783 * 1784 * If FP isn't in use, load FP regs. If VEC isn't in use, load VEC 1785 * regs. Either way, set MSR_VSX. 1786 */ 1787 1788 TM_DEBUG("VSX Unavailable trap whilst transactional at 0x%lx," 1789 "MSR=%lx\n", 1790 regs->nip, regs->msr); 1791 1792 current->thread.used_vsr = 1; 1793 1794 /* This reclaims FP and/or VR regs if they're already enabled */ 1795 tm_reclaim_current(TM_CAUSE_FAC_UNAV); 1796 1797 current->thread.load_vec = 1; 1798 current->thread.load_fp = 1; 1799 1800 tm_recheckpoint(¤t->thread); 1801 } 1802 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ 1803 1804 void performance_monitor_exception(struct pt_regs *regs) 1805 { 1806 __this_cpu_inc(irq_stat.pmu_irqs); 1807 1808 perf_irq(regs); 1809 } 1810 1811 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 1812 static void handle_debug(struct pt_regs *regs, unsigned long debug_status) 1813 { 1814 int changed = 0; 1815 /* 1816 * Determine the cause of the debug event, clear the 1817 * event flags and send a trap to the handler. Torez 1818 */ 1819 if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) { 1820 dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W); 1821 #ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE 1822 current->thread.debug.dbcr2 &= ~DBCR2_DAC12MODE; 1823 #endif 1824 do_send_trap(regs, mfspr(SPRN_DAC1), debug_status, 1825 5); 1826 changed |= 0x01; 1827 } else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) { 1828 dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W); 1829 do_send_trap(regs, mfspr(SPRN_DAC2), debug_status, 1830 6); 1831 changed |= 0x01; 1832 } else if (debug_status & DBSR_IAC1) { 1833 current->thread.debug.dbcr0 &= ~DBCR0_IAC1; 1834 dbcr_iac_range(current) &= ~DBCR_IAC12MODE; 1835 do_send_trap(regs, mfspr(SPRN_IAC1), debug_status, 1836 1); 1837 changed |= 0x01; 1838 } else if (debug_status & DBSR_IAC2) { 1839 current->thread.debug.dbcr0 &= ~DBCR0_IAC2; 1840 do_send_trap(regs, mfspr(SPRN_IAC2), debug_status, 1841 2); 1842 changed |= 0x01; 1843 } else if (debug_status & DBSR_IAC3) { 1844 current->thread.debug.dbcr0 &= ~DBCR0_IAC3; 1845 dbcr_iac_range(current) &= ~DBCR_IAC34MODE; 1846 do_send_trap(regs, mfspr(SPRN_IAC3), debug_status, 1847 3); 1848 changed |= 0x01; 1849 } else if (debug_status & DBSR_IAC4) { 1850 current->thread.debug.dbcr0 &= ~DBCR0_IAC4; 1851 do_send_trap(regs, mfspr(SPRN_IAC4), debug_status, 1852 4); 1853 changed |= 0x01; 1854 } 1855 /* 1856 * At the point this routine was called, the MSR(DE) was turned off. 1857 * Check all other debug flags and see if that bit needs to be turned 1858 * back on or not. 1859 */ 1860 if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0, 1861 current->thread.debug.dbcr1)) 1862 regs->msr |= MSR_DE; 1863 else 1864 /* Make sure the IDM flag is off */ 1865 current->thread.debug.dbcr0 &= ~DBCR0_IDM; 1866 1867 if (changed & 0x01) 1868 mtspr(SPRN_DBCR0, current->thread.debug.dbcr0); 1869 } 1870 1871 void DebugException(struct pt_regs *regs, unsigned long debug_status) 1872 { 1873 current->thread.debug.dbsr = debug_status; 1874 1875 /* Hack alert: On BookE, Branch Taken stops on the branch itself, while 1876 * on server, it stops on the target of the branch. In order to simulate 1877 * the server behaviour, we thus restart right away with a single step 1878 * instead of stopping here when hitting a BT 1879 */ 1880 if (debug_status & DBSR_BT) { 1881 regs->msr &= ~MSR_DE; 1882 1883 /* Disable BT */ 1884 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT); 1885 /* Clear the BT event */ 1886 mtspr(SPRN_DBSR, DBSR_BT); 1887 1888 /* Do the single step trick only when coming from userspace */ 1889 if (user_mode(regs)) { 1890 current->thread.debug.dbcr0 &= ~DBCR0_BT; 1891 current->thread.debug.dbcr0 |= DBCR0_IDM | DBCR0_IC; 1892 regs->msr |= MSR_DE; 1893 return; 1894 } 1895 1896 if (kprobe_post_handler(regs)) 1897 return; 1898 1899 if (notify_die(DIE_SSTEP, "block_step", regs, 5, 1900 5, SIGTRAP) == NOTIFY_STOP) { 1901 return; 1902 } 1903 if (debugger_sstep(regs)) 1904 return; 1905 } else if (debug_status & DBSR_IC) { /* Instruction complete */ 1906 regs->msr &= ~MSR_DE; 1907 1908 /* Disable instruction completion */ 1909 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC); 1910 /* Clear the instruction completion event */ 1911 mtspr(SPRN_DBSR, DBSR_IC); 1912 1913 if (kprobe_post_handler(regs)) 1914 return; 1915 1916 if (notify_die(DIE_SSTEP, "single_step", regs, 5, 1917 5, SIGTRAP) == NOTIFY_STOP) { 1918 return; 1919 } 1920 1921 if (debugger_sstep(regs)) 1922 return; 1923 1924 if (user_mode(regs)) { 1925 current->thread.debug.dbcr0 &= ~DBCR0_IC; 1926 if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0, 1927 current->thread.debug.dbcr1)) 1928 regs->msr |= MSR_DE; 1929 else 1930 /* Make sure the IDM bit is off */ 1931 current->thread.debug.dbcr0 &= ~DBCR0_IDM; 1932 } 1933 1934 _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip); 1935 } else 1936 handle_debug(regs, debug_status); 1937 } 1938 NOKPROBE_SYMBOL(DebugException); 1939 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ 1940 1941 #if !defined(CONFIG_TAU_INT) 1942 void TAUException(struct pt_regs *regs) 1943 { 1944 printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx %s\n", 1945 regs->nip, regs->msr, regs->trap, print_tainted()); 1946 } 1947 #endif /* CONFIG_INT_TAU */ 1948 1949 #ifdef CONFIG_ALTIVEC 1950 void altivec_assist_exception(struct pt_regs *regs) 1951 { 1952 int err; 1953 1954 if (!user_mode(regs)) { 1955 printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode" 1956 " at %lx\n", regs->nip); 1957 die("Kernel VMX/Altivec assist exception", regs, SIGILL); 1958 } 1959 1960 flush_altivec_to_thread(current); 1961 1962 PPC_WARN_EMULATED(altivec, regs); 1963 err = emulate_altivec(regs); 1964 if (err == 0) { 1965 regs->nip += 4; /* skip emulated instruction */ 1966 emulate_single_step(regs); 1967 return; 1968 } 1969 1970 if (err == -EFAULT) { 1971 /* got an error reading the instruction */ 1972 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); 1973 } else { 1974 /* didn't recognize the instruction */ 1975 /* XXX quick hack for now: set the non-Java bit in the VSCR */ 1976 printk_ratelimited(KERN_ERR "Unrecognized altivec instruction " 1977 "in %s at %lx\n", current->comm, regs->nip); 1978 current->thread.vr_state.vscr.u[3] |= 0x10000; 1979 } 1980 } 1981 #endif /* CONFIG_ALTIVEC */ 1982 1983 #ifdef CONFIG_FSL_BOOKE 1984 void CacheLockingException(struct pt_regs *regs, unsigned long address, 1985 unsigned long error_code) 1986 { 1987 /* We treat cache locking instructions from the user 1988 * as priv ops, in the future we could try to do 1989 * something smarter 1990 */ 1991 if (error_code & (ESR_DLK|ESR_ILK)) 1992 _exception(SIGILL, regs, ILL_PRVOPC, regs->nip); 1993 return; 1994 } 1995 #endif /* CONFIG_FSL_BOOKE */ 1996 1997 #ifdef CONFIG_SPE 1998 void SPEFloatingPointException(struct pt_regs *regs) 1999 { 2000 extern int do_spe_mathemu(struct pt_regs *regs); 2001 unsigned long spefscr; 2002 int fpexc_mode; 2003 int code = FPE_FLTUNK; 2004 int err; 2005 2006 flush_spe_to_thread(current); 2007 2008 spefscr = current->thread.spefscr; 2009 fpexc_mode = current->thread.fpexc_mode; 2010 2011 if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) { 2012 code = FPE_FLTOVF; 2013 } 2014 else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) { 2015 code = FPE_FLTUND; 2016 } 2017 else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV)) 2018 code = FPE_FLTDIV; 2019 else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) { 2020 code = FPE_FLTINV; 2021 } 2022 else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES)) 2023 code = FPE_FLTRES; 2024 2025 err = do_spe_mathemu(regs); 2026 if (err == 0) { 2027 regs->nip += 4; /* skip emulated instruction */ 2028 emulate_single_step(regs); 2029 return; 2030 } 2031 2032 if (err == -EFAULT) { 2033 /* got an error reading the instruction */ 2034 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); 2035 } else if (err == -EINVAL) { 2036 /* didn't recognize the instruction */ 2037 printk(KERN_ERR "unrecognized spe instruction " 2038 "in %s at %lx\n", current->comm, regs->nip); 2039 } else { 2040 _exception(SIGFPE, regs, code, regs->nip); 2041 } 2042 2043 return; 2044 } 2045 2046 void SPEFloatingPointRoundException(struct pt_regs *regs) 2047 { 2048 extern int speround_handler(struct pt_regs *regs); 2049 int err; 2050 2051 preempt_disable(); 2052 if (regs->msr & MSR_SPE) 2053 giveup_spe(current); 2054 preempt_enable(); 2055 2056 regs->nip -= 4; 2057 err = speround_handler(regs); 2058 if (err == 0) { 2059 regs->nip += 4; /* skip emulated instruction */ 2060 emulate_single_step(regs); 2061 return; 2062 } 2063 2064 if (err == -EFAULT) { 2065 /* got an error reading the instruction */ 2066 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); 2067 } else if (err == -EINVAL) { 2068 /* didn't recognize the instruction */ 2069 printk(KERN_ERR "unrecognized spe instruction " 2070 "in %s at %lx\n", current->comm, regs->nip); 2071 } else { 2072 _exception(SIGFPE, regs, FPE_FLTUNK, regs->nip); 2073 return; 2074 } 2075 } 2076 #endif 2077 2078 /* 2079 * We enter here if we get an unrecoverable exception, that is, one 2080 * that happened at a point where the RI (recoverable interrupt) bit 2081 * in the MSR is 0. This indicates that SRR0/1 are live, and that 2082 * we therefore lost state by taking this exception. 2083 */ 2084 void unrecoverable_exception(struct pt_regs *regs) 2085 { 2086 pr_emerg("Unrecoverable exception %lx at %lx (msr=%lx)\n", 2087 regs->trap, regs->nip, regs->msr); 2088 die("Unrecoverable exception", regs, SIGABRT); 2089 } 2090 NOKPROBE_SYMBOL(unrecoverable_exception); 2091 2092 #if defined(CONFIG_BOOKE_WDT) || defined(CONFIG_40x) 2093 /* 2094 * Default handler for a Watchdog exception, 2095 * spins until a reboot occurs 2096 */ 2097 void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs) 2098 { 2099 /* Generic WatchdogHandler, implement your own */ 2100 mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE)); 2101 return; 2102 } 2103 2104 void WatchdogException(struct pt_regs *regs) 2105 { 2106 printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n"); 2107 WatchdogHandler(regs); 2108 } 2109 #endif 2110 2111 /* 2112 * We enter here if we discover during exception entry that we are 2113 * running in supervisor mode with a userspace value in the stack pointer. 2114 */ 2115 void kernel_bad_stack(struct pt_regs *regs) 2116 { 2117 printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n", 2118 regs->gpr[1], regs->nip); 2119 die("Bad kernel stack pointer", regs, SIGABRT); 2120 } 2121 NOKPROBE_SYMBOL(kernel_bad_stack); 2122 2123 void __init trap_init(void) 2124 { 2125 } 2126 2127 2128 #ifdef CONFIG_PPC_EMULATED_STATS 2129 2130 #define WARN_EMULATED_SETUP(type) .type = { .name = #type } 2131 2132 struct ppc_emulated ppc_emulated = { 2133 #ifdef CONFIG_ALTIVEC 2134 WARN_EMULATED_SETUP(altivec), 2135 #endif 2136 WARN_EMULATED_SETUP(dcba), 2137 WARN_EMULATED_SETUP(dcbz), 2138 WARN_EMULATED_SETUP(fp_pair), 2139 WARN_EMULATED_SETUP(isel), 2140 WARN_EMULATED_SETUP(mcrxr), 2141 WARN_EMULATED_SETUP(mfpvr), 2142 WARN_EMULATED_SETUP(multiple), 2143 WARN_EMULATED_SETUP(popcntb), 2144 WARN_EMULATED_SETUP(spe), 2145 WARN_EMULATED_SETUP(string), 2146 WARN_EMULATED_SETUP(sync), 2147 WARN_EMULATED_SETUP(unaligned), 2148 #ifdef CONFIG_MATH_EMULATION 2149 WARN_EMULATED_SETUP(math), 2150 #endif 2151 #ifdef CONFIG_VSX 2152 WARN_EMULATED_SETUP(vsx), 2153 #endif 2154 #ifdef CONFIG_PPC64 2155 WARN_EMULATED_SETUP(mfdscr), 2156 WARN_EMULATED_SETUP(mtdscr), 2157 WARN_EMULATED_SETUP(lq_stq), 2158 WARN_EMULATED_SETUP(lxvw4x), 2159 WARN_EMULATED_SETUP(lxvh8x), 2160 WARN_EMULATED_SETUP(lxvd2x), 2161 WARN_EMULATED_SETUP(lxvb16x), 2162 #endif 2163 }; 2164 2165 u32 ppc_warn_emulated; 2166 2167 void ppc_warn_emulated_print(const char *type) 2168 { 2169 pr_warn_ratelimited("%s used emulated %s instruction\n", current->comm, 2170 type); 2171 } 2172 2173 static int __init ppc_warn_emulated_init(void) 2174 { 2175 struct dentry *dir, *d; 2176 unsigned int i; 2177 struct ppc_emulated_entry *entries = (void *)&ppc_emulated; 2178 2179 if (!powerpc_debugfs_root) 2180 return -ENODEV; 2181 2182 dir = debugfs_create_dir("emulated_instructions", 2183 powerpc_debugfs_root); 2184 if (!dir) 2185 return -ENOMEM; 2186 2187 d = debugfs_create_u32("do_warn", 0644, dir, 2188 &ppc_warn_emulated); 2189 if (!d) 2190 goto fail; 2191 2192 for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) { 2193 d = debugfs_create_u32(entries[i].name, 0644, dir, 2194 (u32 *)&entries[i].val.counter); 2195 if (!d) 2196 goto fail; 2197 } 2198 2199 return 0; 2200 2201 fail: 2202 debugfs_remove_recursive(dir); 2203 return -ENOMEM; 2204 } 2205 2206 device_initcall(ppc_warn_emulated_init); 2207 2208 #endif /* CONFIG_PPC_EMULATED_STATS */ 2209