1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 4 * Copyright 2007-2010 Freescale Semiconductor, Inc. 5 * 6 * Modified by Cort Dougan (cort@cs.nmt.edu) 7 * and Paul Mackerras (paulus@samba.org) 8 */ 9 10 /* 11 * This file handles the architecture-dependent parts of hardware exceptions 12 */ 13 14 #include <linux/errno.h> 15 #include <linux/sched.h> 16 #include <linux/sched/debug.h> 17 #include <linux/kernel.h> 18 #include <linux/mm.h> 19 #include <linux/pkeys.h> 20 #include <linux/stddef.h> 21 #include <linux/unistd.h> 22 #include <linux/ptrace.h> 23 #include <linux/user.h> 24 #include <linux/interrupt.h> 25 #include <linux/init.h> 26 #include <linux/extable.h> 27 #include <linux/module.h> /* print_modules */ 28 #include <linux/prctl.h> 29 #include <linux/delay.h> 30 #include <linux/kprobes.h> 31 #include <linux/kexec.h> 32 #include <linux/backlight.h> 33 #include <linux/bug.h> 34 #include <linux/kdebug.h> 35 #include <linux/ratelimit.h> 36 #include <linux/context_tracking.h> 37 #include <linux/smp.h> 38 #include <linux/console.h> 39 #include <linux/kmsg_dump.h> 40 41 #include <asm/emulated_ops.h> 42 #include <linux/uaccess.h> 43 #include <asm/debugfs.h> 44 #include <asm/interrupt.h> 45 #include <asm/io.h> 46 #include <asm/machdep.h> 47 #include <asm/rtas.h> 48 #include <asm/pmc.h> 49 #include <asm/reg.h> 50 #ifdef CONFIG_PMAC_BACKLIGHT 51 #include <asm/backlight.h> 52 #endif 53 #ifdef CONFIG_PPC64 54 #include <asm/firmware.h> 55 #include <asm/processor.h> 56 #endif 57 #include <asm/kexec.h> 58 #include <asm/ppc-opcode.h> 59 #include <asm/rio.h> 60 #include <asm/fadump.h> 61 #include <asm/switch_to.h> 62 #include <asm/tm.h> 63 #include <asm/debug.h> 64 #include <asm/asm-prototypes.h> 65 #include <asm/hmi.h> 66 #include <sysdev/fsl_pci.h> 67 #include <asm/kprobes.h> 68 #include <asm/stacktrace.h> 69 #include <asm/nmi.h> 70 71 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC_CORE) 72 int (*__debugger)(struct pt_regs *regs) __read_mostly; 73 int (*__debugger_ipi)(struct pt_regs *regs) __read_mostly; 74 int (*__debugger_bpt)(struct pt_regs *regs) __read_mostly; 75 int (*__debugger_sstep)(struct pt_regs *regs) __read_mostly; 76 int (*__debugger_iabr_match)(struct pt_regs *regs) __read_mostly; 77 int (*__debugger_break_match)(struct pt_regs *regs) __read_mostly; 78 int (*__debugger_fault_handler)(struct pt_regs *regs) __read_mostly; 79 80 EXPORT_SYMBOL(__debugger); 81 EXPORT_SYMBOL(__debugger_ipi); 82 EXPORT_SYMBOL(__debugger_bpt); 83 EXPORT_SYMBOL(__debugger_sstep); 84 EXPORT_SYMBOL(__debugger_iabr_match); 85 EXPORT_SYMBOL(__debugger_break_match); 86 EXPORT_SYMBOL(__debugger_fault_handler); 87 #endif 88 89 /* Transactional Memory trap debug */ 90 #ifdef TM_DEBUG_SW 91 #define TM_DEBUG(x...) printk(KERN_INFO x) 92 #else 93 #define TM_DEBUG(x...) do { } while(0) 94 #endif 95 96 static const char *signame(int signr) 97 { 98 switch (signr) { 99 case SIGBUS: return "bus error"; 100 case SIGFPE: return "floating point exception"; 101 case SIGILL: return "illegal instruction"; 102 case SIGSEGV: return "segfault"; 103 case SIGTRAP: return "unhandled trap"; 104 } 105 106 return "unknown signal"; 107 } 108 109 /* 110 * Trap & Exception support 111 */ 112 113 #ifdef CONFIG_PMAC_BACKLIGHT 114 static void pmac_backlight_unblank(void) 115 { 116 mutex_lock(&pmac_backlight_mutex); 117 if (pmac_backlight) { 118 struct backlight_properties *props; 119 120 props = &pmac_backlight->props; 121 props->brightness = props->max_brightness; 122 props->power = FB_BLANK_UNBLANK; 123 backlight_update_status(pmac_backlight); 124 } 125 mutex_unlock(&pmac_backlight_mutex); 126 } 127 #else 128 static inline void pmac_backlight_unblank(void) { } 129 #endif 130 131 /* 132 * If oops/die is expected to crash the machine, return true here. 133 * 134 * This should not be expected to be 100% accurate, there may be 135 * notifiers registered or other unexpected conditions that may bring 136 * down the kernel. Or if the current process in the kernel is holding 137 * locks or has other critical state, the kernel may become effectively 138 * unusable anyway. 139 */ 140 bool die_will_crash(void) 141 { 142 if (should_fadump_crash()) 143 return true; 144 if (kexec_should_crash(current)) 145 return true; 146 if (in_interrupt() || panic_on_oops || 147 !current->pid || is_global_init(current)) 148 return true; 149 150 return false; 151 } 152 153 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; 154 static int die_owner = -1; 155 static unsigned int die_nest_count; 156 static int die_counter; 157 158 extern void panic_flush_kmsg_start(void) 159 { 160 /* 161 * These are mostly taken from kernel/panic.c, but tries to do 162 * relatively minimal work. Don't use delay functions (TB may 163 * be broken), don't crash dump (need to set a firmware log), 164 * don't run notifiers. We do want to get some information to 165 * Linux console. 166 */ 167 console_verbose(); 168 bust_spinlocks(1); 169 } 170 171 extern void panic_flush_kmsg_end(void) 172 { 173 printk_safe_flush_on_panic(); 174 kmsg_dump(KMSG_DUMP_PANIC); 175 bust_spinlocks(0); 176 debug_locks_off(); 177 console_flush_on_panic(CONSOLE_FLUSH_PENDING); 178 } 179 180 static unsigned long oops_begin(struct pt_regs *regs) 181 { 182 int cpu; 183 unsigned long flags; 184 185 oops_enter(); 186 187 /* racy, but better than risking deadlock. */ 188 raw_local_irq_save(flags); 189 cpu = smp_processor_id(); 190 if (!arch_spin_trylock(&die_lock)) { 191 if (cpu == die_owner) 192 /* nested oops. should stop eventually */; 193 else 194 arch_spin_lock(&die_lock); 195 } 196 die_nest_count++; 197 die_owner = cpu; 198 console_verbose(); 199 bust_spinlocks(1); 200 if (machine_is(powermac)) 201 pmac_backlight_unblank(); 202 return flags; 203 } 204 NOKPROBE_SYMBOL(oops_begin); 205 206 static void oops_end(unsigned long flags, struct pt_regs *regs, 207 int signr) 208 { 209 bust_spinlocks(0); 210 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 211 die_nest_count--; 212 oops_exit(); 213 printk("\n"); 214 if (!die_nest_count) { 215 /* Nest count reaches zero, release the lock. */ 216 die_owner = -1; 217 arch_spin_unlock(&die_lock); 218 } 219 raw_local_irq_restore(flags); 220 221 /* 222 * system_reset_excption handles debugger, crash dump, panic, for 0x100 223 */ 224 if (TRAP(regs) == INTERRUPT_SYSTEM_RESET) 225 return; 226 227 crash_fadump(regs, "die oops"); 228 229 if (kexec_should_crash(current)) 230 crash_kexec(regs); 231 232 if (!signr) 233 return; 234 235 /* 236 * While our oops output is serialised by a spinlock, output 237 * from panic() called below can race and corrupt it. If we 238 * know we are going to panic, delay for 1 second so we have a 239 * chance to get clean backtraces from all CPUs that are oopsing. 240 */ 241 if (in_interrupt() || panic_on_oops || !current->pid || 242 is_global_init(current)) { 243 mdelay(MSEC_PER_SEC); 244 } 245 246 if (panic_on_oops) 247 panic("Fatal exception"); 248 do_exit(signr); 249 } 250 NOKPROBE_SYMBOL(oops_end); 251 252 static char *get_mmu_str(void) 253 { 254 if (early_radix_enabled()) 255 return " MMU=Radix"; 256 if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) 257 return " MMU=Hash"; 258 return ""; 259 } 260 261 static int __die(const char *str, struct pt_regs *regs, long err) 262 { 263 printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); 264 265 printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s %s\n", 266 IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE", 267 PAGE_SIZE / 1024, get_mmu_str(), 268 IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "", 269 IS_ENABLED(CONFIG_SMP) ? " SMP" : "", 270 IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "", 271 debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "", 272 IS_ENABLED(CONFIG_NUMA) ? " NUMA" : "", 273 ppc_md.name ? ppc_md.name : ""); 274 275 if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP) 276 return 1; 277 278 print_modules(); 279 show_regs(regs); 280 281 return 0; 282 } 283 NOKPROBE_SYMBOL(__die); 284 285 void die(const char *str, struct pt_regs *regs, long err) 286 { 287 unsigned long flags; 288 289 /* 290 * system_reset_excption handles debugger, crash dump, panic, for 0x100 291 */ 292 if (TRAP(regs) != INTERRUPT_SYSTEM_RESET) { 293 if (debugger(regs)) 294 return; 295 } 296 297 flags = oops_begin(regs); 298 if (__die(str, regs, err)) 299 err = 0; 300 oops_end(flags, regs, err); 301 } 302 NOKPROBE_SYMBOL(die); 303 304 void user_single_step_report(struct pt_regs *regs) 305 { 306 force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)regs->nip); 307 } 308 309 static void show_signal_msg(int signr, struct pt_regs *regs, int code, 310 unsigned long addr) 311 { 312 static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, 313 DEFAULT_RATELIMIT_BURST); 314 315 if (!show_unhandled_signals) 316 return; 317 318 if (!unhandled_signal(current, signr)) 319 return; 320 321 if (!__ratelimit(&rs)) 322 return; 323 324 pr_info("%s[%d]: %s (%d) at %lx nip %lx lr %lx code %x", 325 current->comm, current->pid, signame(signr), signr, 326 addr, regs->nip, regs->link, code); 327 328 print_vma_addr(KERN_CONT " in ", regs->nip); 329 330 pr_cont("\n"); 331 332 show_user_instructions(regs); 333 } 334 335 static bool exception_common(int signr, struct pt_regs *regs, int code, 336 unsigned long addr) 337 { 338 if (!user_mode(regs)) { 339 die("Exception in kernel mode", regs, signr); 340 return false; 341 } 342 343 show_signal_msg(signr, regs, code, addr); 344 345 if (arch_irqs_disabled()) 346 interrupt_cond_local_irq_enable(regs); 347 348 current->thread.trap_nr = code; 349 350 return true; 351 } 352 353 void _exception_pkey(struct pt_regs *regs, unsigned long addr, int key) 354 { 355 if (!exception_common(SIGSEGV, regs, SEGV_PKUERR, addr)) 356 return; 357 358 force_sig_pkuerr((void __user *) addr, key); 359 } 360 361 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) 362 { 363 if (!exception_common(signr, regs, code, addr)) 364 return; 365 366 force_sig_fault(signr, code, (void __user *)addr); 367 } 368 369 /* 370 * The interrupt architecture has a quirk in that the HV interrupts excluding 371 * the NMIs (0x100 and 0x200) do not clear MSR[RI] at entry. The first thing 372 * that an interrupt handler must do is save off a GPR into a scratch register, 373 * and all interrupts on POWERNV (HV=1) use the HSPRG1 register as scratch. 374 * Therefore an NMI can clobber an HV interrupt's live HSPRG1 without noticing 375 * that it is non-reentrant, which leads to random data corruption. 376 * 377 * The solution is for NMI interrupts in HV mode to check if they originated 378 * from these critical HV interrupt regions. If so, then mark them not 379 * recoverable. 380 * 381 * An alternative would be for HV NMIs to use SPRG for scratch to avoid the 382 * HSPRG1 clobber, however this would cause guest SPRG to be clobbered. Linux 383 * guests should always have MSR[RI]=0 when its scratch SPRG is in use, so 384 * that would work. However any other guest OS that may have the SPRG live 385 * and MSR[RI]=1 could encounter silent corruption. 386 * 387 * Builds that do not support KVM could take this second option to increase 388 * the recoverability of NMIs. 389 */ 390 void hv_nmi_check_nonrecoverable(struct pt_regs *regs) 391 { 392 #ifdef CONFIG_PPC_POWERNV 393 unsigned long kbase = (unsigned long)_stext; 394 unsigned long nip = regs->nip; 395 396 if (!(regs->msr & MSR_RI)) 397 return; 398 if (!(regs->msr & MSR_HV)) 399 return; 400 if (regs->msr & MSR_PR) 401 return; 402 403 /* 404 * Now test if the interrupt has hit a range that may be using 405 * HSPRG1 without having RI=0 (i.e., an HSRR interrupt). The 406 * problem ranges all run un-relocated. Test real and virt modes 407 * at the same time by dropping the high bit of the nip (virt mode 408 * entry points still have the +0x4000 offset). 409 */ 410 nip &= ~0xc000000000000000ULL; 411 if ((nip >= 0x500 && nip < 0x600) || (nip >= 0x4500 && nip < 0x4600)) 412 goto nonrecoverable; 413 if ((nip >= 0x980 && nip < 0xa00) || (nip >= 0x4980 && nip < 0x4a00)) 414 goto nonrecoverable; 415 if ((nip >= 0xe00 && nip < 0xec0) || (nip >= 0x4e00 && nip < 0x4ec0)) 416 goto nonrecoverable; 417 if ((nip >= 0xf80 && nip < 0xfa0) || (nip >= 0x4f80 && nip < 0x4fa0)) 418 goto nonrecoverable; 419 420 /* Trampoline code runs un-relocated so subtract kbase. */ 421 if (nip >= (unsigned long)(start_real_trampolines - kbase) && 422 nip < (unsigned long)(end_real_trampolines - kbase)) 423 goto nonrecoverable; 424 if (nip >= (unsigned long)(start_virt_trampolines - kbase) && 425 nip < (unsigned long)(end_virt_trampolines - kbase)) 426 goto nonrecoverable; 427 return; 428 429 nonrecoverable: 430 regs->msr &= ~MSR_RI; 431 #endif 432 } 433 DEFINE_INTERRUPT_HANDLER_NMI(system_reset_exception) 434 { 435 unsigned long hsrr0, hsrr1; 436 bool saved_hsrrs = false; 437 438 /* 439 * System reset can interrupt code where HSRRs are live and MSR[RI]=1. 440 * The system reset interrupt itself may clobber HSRRs (e.g., to call 441 * OPAL), so save them here and restore them before returning. 442 * 443 * Machine checks don't need to save HSRRs, as the real mode handler 444 * is careful to avoid them, and the regular handler is not delivered 445 * as an NMI. 446 */ 447 if (cpu_has_feature(CPU_FTR_HVMODE)) { 448 hsrr0 = mfspr(SPRN_HSRR0); 449 hsrr1 = mfspr(SPRN_HSRR1); 450 saved_hsrrs = true; 451 } 452 453 hv_nmi_check_nonrecoverable(regs); 454 455 __this_cpu_inc(irq_stat.sreset_irqs); 456 457 /* See if any machine dependent calls */ 458 if (ppc_md.system_reset_exception) { 459 if (ppc_md.system_reset_exception(regs)) 460 goto out; 461 } 462 463 if (debugger(regs)) 464 goto out; 465 466 kmsg_dump(KMSG_DUMP_OOPS); 467 /* 468 * A system reset is a request to dump, so we always send 469 * it through the crashdump code (if fadump or kdump are 470 * registered). 471 */ 472 crash_fadump(regs, "System Reset"); 473 474 crash_kexec(regs); 475 476 /* 477 * We aren't the primary crash CPU. We need to send it 478 * to a holding pattern to avoid it ending up in the panic 479 * code. 480 */ 481 crash_kexec_secondary(regs); 482 483 /* 484 * No debugger or crash dump registered, print logs then 485 * panic. 486 */ 487 die("System Reset", regs, SIGABRT); 488 489 mdelay(2*MSEC_PER_SEC); /* Wait a little while for others to print */ 490 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 491 nmi_panic(regs, "System Reset"); 492 493 out: 494 #ifdef CONFIG_PPC_BOOK3S_64 495 BUG_ON(get_paca()->in_nmi == 0); 496 if (get_paca()->in_nmi > 1) 497 die("Unrecoverable nested System Reset", regs, SIGABRT); 498 #endif 499 /* Must die if the interrupt is not recoverable */ 500 if (!(regs->msr & MSR_RI)) { 501 /* For the reason explained in die_mce, nmi_exit before die */ 502 nmi_exit(); 503 die("Unrecoverable System Reset", regs, SIGABRT); 504 } 505 506 if (saved_hsrrs) { 507 mtspr(SPRN_HSRR0, hsrr0); 508 mtspr(SPRN_HSRR1, hsrr1); 509 } 510 511 /* What should we do here? We could issue a shutdown or hard reset. */ 512 513 return 0; 514 } 515 516 /* 517 * I/O accesses can cause machine checks on powermacs. 518 * Check if the NIP corresponds to the address of a sync 519 * instruction for which there is an entry in the exception 520 * table. 521 * -- paulus. 522 */ 523 static inline int check_io_access(struct pt_regs *regs) 524 { 525 #ifdef CONFIG_PPC32 526 unsigned long msr = regs->msr; 527 const struct exception_table_entry *entry; 528 unsigned int *nip = (unsigned int *)regs->nip; 529 530 if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000))) 531 && (entry = search_exception_tables(regs->nip)) != NULL) { 532 /* 533 * Check that it's a sync instruction, or somewhere 534 * in the twi; isync; nop sequence that inb/inw/inl uses. 535 * As the address is in the exception table 536 * we should be able to read the instr there. 537 * For the debug message, we look at the preceding 538 * load or store. 539 */ 540 if (*nip == PPC_INST_NOP) 541 nip -= 2; 542 else if (*nip == PPC_INST_ISYNC) 543 --nip; 544 if (*nip == PPC_INST_SYNC || (*nip >> 26) == OP_TRAP) { 545 unsigned int rb; 546 547 --nip; 548 rb = (*nip >> 11) & 0x1f; 549 printk(KERN_DEBUG "%s bad port %lx at %p\n", 550 (*nip & 0x100)? "OUT to": "IN from", 551 regs->gpr[rb] - _IO_BASE, nip); 552 regs->msr |= MSR_RI; 553 regs->nip = extable_fixup(entry); 554 return 1; 555 } 556 } 557 #endif /* CONFIG_PPC32 */ 558 return 0; 559 } 560 561 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 562 /* On 4xx, the reason for the machine check or program exception 563 is in the ESR. */ 564 #define get_reason(regs) ((regs)->dsisr) 565 #define REASON_FP ESR_FP 566 #define REASON_ILLEGAL (ESR_PIL | ESR_PUO) 567 #define REASON_PRIVILEGED ESR_PPR 568 #define REASON_TRAP ESR_PTR 569 #define REASON_PREFIXED 0 570 #define REASON_BOUNDARY 0 571 572 /* single-step stuff */ 573 #define single_stepping(regs) (current->thread.debug.dbcr0 & DBCR0_IC) 574 #define clear_single_step(regs) (current->thread.debug.dbcr0 &= ~DBCR0_IC) 575 #define clear_br_trace(regs) do {} while(0) 576 #else 577 /* On non-4xx, the reason for the machine check or program 578 exception is in the MSR. */ 579 #define get_reason(regs) ((regs)->msr) 580 #define REASON_TM SRR1_PROGTM 581 #define REASON_FP SRR1_PROGFPE 582 #define REASON_ILLEGAL SRR1_PROGILL 583 #define REASON_PRIVILEGED SRR1_PROGPRIV 584 #define REASON_TRAP SRR1_PROGTRAP 585 #define REASON_PREFIXED SRR1_PREFIXED 586 #define REASON_BOUNDARY SRR1_BOUNDARY 587 588 #define single_stepping(regs) ((regs)->msr & MSR_SE) 589 #define clear_single_step(regs) ((regs)->msr &= ~MSR_SE) 590 #define clear_br_trace(regs) ((regs)->msr &= ~MSR_BE) 591 #endif 592 593 #define inst_length(reason) (((reason) & REASON_PREFIXED) ? 8 : 4) 594 595 #if defined(CONFIG_E500) 596 int machine_check_e500mc(struct pt_regs *regs) 597 { 598 unsigned long mcsr = mfspr(SPRN_MCSR); 599 unsigned long pvr = mfspr(SPRN_PVR); 600 unsigned long reason = mcsr; 601 int recoverable = 1; 602 603 if (reason & MCSR_LD) { 604 recoverable = fsl_rio_mcheck_exception(regs); 605 if (recoverable == 1) 606 goto silent_out; 607 } 608 609 printk("Machine check in kernel mode.\n"); 610 printk("Caused by (from MCSR=%lx): ", reason); 611 612 if (reason & MCSR_MCP) 613 pr_cont("Machine Check Signal\n"); 614 615 if (reason & MCSR_ICPERR) { 616 pr_cont("Instruction Cache Parity Error\n"); 617 618 /* 619 * This is recoverable by invalidating the i-cache. 620 */ 621 mtspr(SPRN_L1CSR1, mfspr(SPRN_L1CSR1) | L1CSR1_ICFI); 622 while (mfspr(SPRN_L1CSR1) & L1CSR1_ICFI) 623 ; 624 625 /* 626 * This will generally be accompanied by an instruction 627 * fetch error report -- only treat MCSR_IF as fatal 628 * if it wasn't due to an L1 parity error. 629 */ 630 reason &= ~MCSR_IF; 631 } 632 633 if (reason & MCSR_DCPERR_MC) { 634 pr_cont("Data Cache Parity Error\n"); 635 636 /* 637 * In write shadow mode we auto-recover from the error, but it 638 * may still get logged and cause a machine check. We should 639 * only treat the non-write shadow case as non-recoverable. 640 */ 641 /* On e6500 core, L1 DCWS (Data cache write shadow mode) bit 642 * is not implemented but L1 data cache always runs in write 643 * shadow mode. Hence on data cache parity errors HW will 644 * automatically invalidate the L1 Data Cache. 645 */ 646 if (PVR_VER(pvr) != PVR_VER_E6500) { 647 if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS)) 648 recoverable = 0; 649 } 650 } 651 652 if (reason & MCSR_L2MMU_MHIT) { 653 pr_cont("Hit on multiple TLB entries\n"); 654 recoverable = 0; 655 } 656 657 if (reason & MCSR_NMI) 658 pr_cont("Non-maskable interrupt\n"); 659 660 if (reason & MCSR_IF) { 661 pr_cont("Instruction Fetch Error Report\n"); 662 recoverable = 0; 663 } 664 665 if (reason & MCSR_LD) { 666 pr_cont("Load Error Report\n"); 667 recoverable = 0; 668 } 669 670 if (reason & MCSR_ST) { 671 pr_cont("Store Error Report\n"); 672 recoverable = 0; 673 } 674 675 if (reason & MCSR_LDG) { 676 pr_cont("Guarded Load Error Report\n"); 677 recoverable = 0; 678 } 679 680 if (reason & MCSR_TLBSYNC) 681 pr_cont("Simultaneous tlbsync operations\n"); 682 683 if (reason & MCSR_BSL2_ERR) { 684 pr_cont("Level 2 Cache Error\n"); 685 recoverable = 0; 686 } 687 688 if (reason & MCSR_MAV) { 689 u64 addr; 690 691 addr = mfspr(SPRN_MCAR); 692 addr |= (u64)mfspr(SPRN_MCARU) << 32; 693 694 pr_cont("Machine Check %s Address: %#llx\n", 695 reason & MCSR_MEA ? "Effective" : "Physical", addr); 696 } 697 698 silent_out: 699 mtspr(SPRN_MCSR, mcsr); 700 return mfspr(SPRN_MCSR) == 0 && recoverable; 701 } 702 703 int machine_check_e500(struct pt_regs *regs) 704 { 705 unsigned long reason = mfspr(SPRN_MCSR); 706 707 if (reason & MCSR_BUS_RBERR) { 708 if (fsl_rio_mcheck_exception(regs)) 709 return 1; 710 if (fsl_pci_mcheck_exception(regs)) 711 return 1; 712 } 713 714 printk("Machine check in kernel mode.\n"); 715 printk("Caused by (from MCSR=%lx): ", reason); 716 717 if (reason & MCSR_MCP) 718 pr_cont("Machine Check Signal\n"); 719 if (reason & MCSR_ICPERR) 720 pr_cont("Instruction Cache Parity Error\n"); 721 if (reason & MCSR_DCP_PERR) 722 pr_cont("Data Cache Push Parity Error\n"); 723 if (reason & MCSR_DCPERR) 724 pr_cont("Data Cache Parity Error\n"); 725 if (reason & MCSR_BUS_IAERR) 726 pr_cont("Bus - Instruction Address Error\n"); 727 if (reason & MCSR_BUS_RAERR) 728 pr_cont("Bus - Read Address Error\n"); 729 if (reason & MCSR_BUS_WAERR) 730 pr_cont("Bus - Write Address Error\n"); 731 if (reason & MCSR_BUS_IBERR) 732 pr_cont("Bus - Instruction Data Error\n"); 733 if (reason & MCSR_BUS_RBERR) 734 pr_cont("Bus - Read Data Bus Error\n"); 735 if (reason & MCSR_BUS_WBERR) 736 pr_cont("Bus - Write Data Bus Error\n"); 737 if (reason & MCSR_BUS_IPERR) 738 pr_cont("Bus - Instruction Parity Error\n"); 739 if (reason & MCSR_BUS_RPERR) 740 pr_cont("Bus - Read Parity Error\n"); 741 742 return 0; 743 } 744 745 int machine_check_generic(struct pt_regs *regs) 746 { 747 return 0; 748 } 749 #elif defined(CONFIG_PPC32) 750 int machine_check_generic(struct pt_regs *regs) 751 { 752 unsigned long reason = regs->msr; 753 754 printk("Machine check in kernel mode.\n"); 755 printk("Caused by (from SRR1=%lx): ", reason); 756 switch (reason & 0x601F0000) { 757 case 0x80000: 758 pr_cont("Machine check signal\n"); 759 break; 760 case 0x40000: 761 case 0x140000: /* 7450 MSS error and TEA */ 762 pr_cont("Transfer error ack signal\n"); 763 break; 764 case 0x20000: 765 pr_cont("Data parity error signal\n"); 766 break; 767 case 0x10000: 768 pr_cont("Address parity error signal\n"); 769 break; 770 case 0x20000000: 771 pr_cont("L1 Data Cache error\n"); 772 break; 773 case 0x40000000: 774 pr_cont("L1 Instruction Cache error\n"); 775 break; 776 case 0x00100000: 777 pr_cont("L2 data cache parity error\n"); 778 break; 779 default: 780 pr_cont("Unknown values in msr\n"); 781 } 782 return 0; 783 } 784 #endif /* everything else */ 785 786 void die_mce(const char *str, struct pt_regs *regs, long err) 787 { 788 /* 789 * The machine check wants to kill the interrupted context, but 790 * do_exit() checks for in_interrupt() and panics in that case, so 791 * exit the irq/nmi before calling die. 792 */ 793 if (IS_ENABLED(CONFIG_PPC_BOOK3S_64)) 794 irq_exit(); 795 else 796 nmi_exit(); 797 die(str, regs, err); 798 } 799 800 /* 801 * BOOK3S_64 does not call this handler as a non-maskable interrupt 802 * (it uses its own early real-mode handler to handle the MCE proper 803 * and then raises irq_work to call this handler when interrupts are 804 * enabled). 805 */ 806 #ifdef CONFIG_PPC_BOOK3S_64 807 DEFINE_INTERRUPT_HANDLER_ASYNC(machine_check_exception) 808 #else 809 DEFINE_INTERRUPT_HANDLER_NMI(machine_check_exception) 810 #endif 811 { 812 int recover = 0; 813 814 __this_cpu_inc(irq_stat.mce_exceptions); 815 816 add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); 817 818 /* See if any machine dependent calls. In theory, we would want 819 * to call the CPU first, and call the ppc_md. one if the CPU 820 * one returns a positive number. However there is existing code 821 * that assumes the board gets a first chance, so let's keep it 822 * that way for now and fix things later. --BenH. 823 */ 824 if (ppc_md.machine_check_exception) 825 recover = ppc_md.machine_check_exception(regs); 826 else if (cur_cpu_spec->machine_check) 827 recover = cur_cpu_spec->machine_check(regs); 828 829 if (recover > 0) 830 goto bail; 831 832 if (debugger_fault_handler(regs)) 833 goto bail; 834 835 if (check_io_access(regs)) 836 goto bail; 837 838 die_mce("Machine check", regs, SIGBUS); 839 840 bail: 841 /* Must die if the interrupt is not recoverable */ 842 if (!(regs->msr & MSR_RI)) 843 die_mce("Unrecoverable Machine check", regs, SIGBUS); 844 845 #ifdef CONFIG_PPC_BOOK3S_64 846 return; 847 #else 848 return 0; 849 #endif 850 } 851 852 DEFINE_INTERRUPT_HANDLER(SMIException) /* async? */ 853 { 854 die("System Management Interrupt", regs, SIGABRT); 855 } 856 857 #ifdef CONFIG_VSX 858 static void p9_hmi_special_emu(struct pt_regs *regs) 859 { 860 unsigned int ra, rb, t, i, sel, instr, rc; 861 const void __user *addr; 862 u8 vbuf[16] __aligned(16), *vdst; 863 unsigned long ea, msr, msr_mask; 864 bool swap; 865 866 if (__get_user(instr, (unsigned int __user *)regs->nip)) 867 return; 868 869 /* 870 * lxvb16x opcode: 0x7c0006d8 871 * lxvd2x opcode: 0x7c000698 872 * lxvh8x opcode: 0x7c000658 873 * lxvw4x opcode: 0x7c000618 874 */ 875 if ((instr & 0xfc00073e) != 0x7c000618) { 876 pr_devel("HMI vec emu: not vector CI %i:%s[%d] nip=%016lx" 877 " instr=%08x\n", 878 smp_processor_id(), current->comm, current->pid, 879 regs->nip, instr); 880 return; 881 } 882 883 /* Grab vector registers into the task struct */ 884 msr = regs->msr; /* Grab msr before we flush the bits */ 885 flush_vsx_to_thread(current); 886 enable_kernel_altivec(); 887 888 /* 889 * Is userspace running with a different endian (this is rare but 890 * not impossible) 891 */ 892 swap = (msr & MSR_LE) != (MSR_KERNEL & MSR_LE); 893 894 /* Decode the instruction */ 895 ra = (instr >> 16) & 0x1f; 896 rb = (instr >> 11) & 0x1f; 897 t = (instr >> 21) & 0x1f; 898 if (instr & 1) 899 vdst = (u8 *)¤t->thread.vr_state.vr[t]; 900 else 901 vdst = (u8 *)¤t->thread.fp_state.fpr[t][0]; 902 903 /* Grab the vector address */ 904 ea = regs->gpr[rb] + (ra ? regs->gpr[ra] : 0); 905 if (is_32bit_task()) 906 ea &= 0xfffffffful; 907 addr = (__force const void __user *)ea; 908 909 /* Check it */ 910 if (!access_ok(addr, 16)) { 911 pr_devel("HMI vec emu: bad access %i:%s[%d] nip=%016lx" 912 " instr=%08x addr=%016lx\n", 913 smp_processor_id(), current->comm, current->pid, 914 regs->nip, instr, (unsigned long)addr); 915 return; 916 } 917 918 /* Read the vector */ 919 rc = 0; 920 if ((unsigned long)addr & 0xfUL) 921 /* unaligned case */ 922 rc = __copy_from_user_inatomic(vbuf, addr, 16); 923 else 924 __get_user_atomic_128_aligned(vbuf, addr, rc); 925 if (rc) { 926 pr_devel("HMI vec emu: page fault %i:%s[%d] nip=%016lx" 927 " instr=%08x addr=%016lx\n", 928 smp_processor_id(), current->comm, current->pid, 929 regs->nip, instr, (unsigned long)addr); 930 return; 931 } 932 933 pr_devel("HMI vec emu: emulated vector CI %i:%s[%d] nip=%016lx" 934 " instr=%08x addr=%016lx\n", 935 smp_processor_id(), current->comm, current->pid, regs->nip, 936 instr, (unsigned long) addr); 937 938 /* Grab instruction "selector" */ 939 sel = (instr >> 6) & 3; 940 941 /* 942 * Check to make sure the facility is actually enabled. This 943 * could happen if we get a false positive hit. 944 * 945 * lxvd2x/lxvw4x always check MSR VSX sel = 0,2 946 * lxvh8x/lxvb16x check MSR VSX or VEC depending on VSR used sel = 1,3 947 */ 948 msr_mask = MSR_VSX; 949 if ((sel & 1) && (instr & 1)) /* lxvh8x & lxvb16x + VSR >= 32 */ 950 msr_mask = MSR_VEC; 951 if (!(msr & msr_mask)) { 952 pr_devel("HMI vec emu: MSR fac clear %i:%s[%d] nip=%016lx" 953 " instr=%08x msr:%016lx\n", 954 smp_processor_id(), current->comm, current->pid, 955 regs->nip, instr, msr); 956 return; 957 } 958 959 /* Do logging here before we modify sel based on endian */ 960 switch (sel) { 961 case 0: /* lxvw4x */ 962 PPC_WARN_EMULATED(lxvw4x, regs); 963 break; 964 case 1: /* lxvh8x */ 965 PPC_WARN_EMULATED(lxvh8x, regs); 966 break; 967 case 2: /* lxvd2x */ 968 PPC_WARN_EMULATED(lxvd2x, regs); 969 break; 970 case 3: /* lxvb16x */ 971 PPC_WARN_EMULATED(lxvb16x, regs); 972 break; 973 } 974 975 #ifdef __LITTLE_ENDIAN__ 976 /* 977 * An LE kernel stores the vector in the task struct as an LE 978 * byte array (effectively swapping both the components and 979 * the content of the components). Those instructions expect 980 * the components to remain in ascending address order, so we 981 * swap them back. 982 * 983 * If we are running a BE user space, the expectation is that 984 * of a simple memcpy, so forcing the emulation to look like 985 * a lxvb16x should do the trick. 986 */ 987 if (swap) 988 sel = 3; 989 990 switch (sel) { 991 case 0: /* lxvw4x */ 992 for (i = 0; i < 4; i++) 993 ((u32 *)vdst)[i] = ((u32 *)vbuf)[3-i]; 994 break; 995 case 1: /* lxvh8x */ 996 for (i = 0; i < 8; i++) 997 ((u16 *)vdst)[i] = ((u16 *)vbuf)[7-i]; 998 break; 999 case 2: /* lxvd2x */ 1000 for (i = 0; i < 2; i++) 1001 ((u64 *)vdst)[i] = ((u64 *)vbuf)[1-i]; 1002 break; 1003 case 3: /* lxvb16x */ 1004 for (i = 0; i < 16; i++) 1005 vdst[i] = vbuf[15-i]; 1006 break; 1007 } 1008 #else /* __LITTLE_ENDIAN__ */ 1009 /* On a big endian kernel, a BE userspace only needs a memcpy */ 1010 if (!swap) 1011 sel = 3; 1012 1013 /* Otherwise, we need to swap the content of the components */ 1014 switch (sel) { 1015 case 0: /* lxvw4x */ 1016 for (i = 0; i < 4; i++) 1017 ((u32 *)vdst)[i] = cpu_to_le32(((u32 *)vbuf)[i]); 1018 break; 1019 case 1: /* lxvh8x */ 1020 for (i = 0; i < 8; i++) 1021 ((u16 *)vdst)[i] = cpu_to_le16(((u16 *)vbuf)[i]); 1022 break; 1023 case 2: /* lxvd2x */ 1024 for (i = 0; i < 2; i++) 1025 ((u64 *)vdst)[i] = cpu_to_le64(((u64 *)vbuf)[i]); 1026 break; 1027 case 3: /* lxvb16x */ 1028 memcpy(vdst, vbuf, 16); 1029 break; 1030 } 1031 #endif /* !__LITTLE_ENDIAN__ */ 1032 1033 /* Go to next instruction */ 1034 regs->nip += 4; 1035 } 1036 #endif /* CONFIG_VSX */ 1037 1038 DEFINE_INTERRUPT_HANDLER_ASYNC(handle_hmi_exception) 1039 { 1040 struct pt_regs *old_regs; 1041 1042 old_regs = set_irq_regs(regs); 1043 1044 #ifdef CONFIG_VSX 1045 /* Real mode flagged P9 special emu is needed */ 1046 if (local_paca->hmi_p9_special_emu) { 1047 local_paca->hmi_p9_special_emu = 0; 1048 1049 /* 1050 * We don't want to take page faults while doing the 1051 * emulation, we just replay the instruction if necessary. 1052 */ 1053 pagefault_disable(); 1054 p9_hmi_special_emu(regs); 1055 pagefault_enable(); 1056 } 1057 #endif /* CONFIG_VSX */ 1058 1059 if (ppc_md.handle_hmi_exception) 1060 ppc_md.handle_hmi_exception(regs); 1061 1062 set_irq_regs(old_regs); 1063 } 1064 1065 DEFINE_INTERRUPT_HANDLER(unknown_exception) 1066 { 1067 printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", 1068 regs->nip, regs->msr, regs->trap); 1069 1070 _exception(SIGTRAP, regs, TRAP_UNK, 0); 1071 } 1072 1073 DEFINE_INTERRUPT_HANDLER_ASYNC(unknown_async_exception) 1074 { 1075 printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", 1076 regs->nip, regs->msr, regs->trap); 1077 1078 _exception(SIGTRAP, regs, TRAP_UNK, 0); 1079 } 1080 1081 DEFINE_INTERRUPT_HANDLER_NMI(unknown_nmi_exception) 1082 { 1083 printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", 1084 regs->nip, regs->msr, regs->trap); 1085 1086 _exception(SIGTRAP, regs, TRAP_UNK, 0); 1087 1088 return 0; 1089 } 1090 1091 DEFINE_INTERRUPT_HANDLER(instruction_breakpoint_exception) 1092 { 1093 if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5, 1094 5, SIGTRAP) == NOTIFY_STOP) 1095 return; 1096 if (debugger_iabr_match(regs)) 1097 return; 1098 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip); 1099 } 1100 1101 DEFINE_INTERRUPT_HANDLER(RunModeException) 1102 { 1103 _exception(SIGTRAP, regs, TRAP_UNK, 0); 1104 } 1105 1106 DEFINE_INTERRUPT_HANDLER(single_step_exception) 1107 { 1108 clear_single_step(regs); 1109 clear_br_trace(regs); 1110 1111 if (kprobe_post_handler(regs)) 1112 return; 1113 1114 if (notify_die(DIE_SSTEP, "single_step", regs, 5, 1115 5, SIGTRAP) == NOTIFY_STOP) 1116 return; 1117 if (debugger_sstep(regs)) 1118 return; 1119 1120 _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip); 1121 } 1122 1123 /* 1124 * After we have successfully emulated an instruction, we have to 1125 * check if the instruction was being single-stepped, and if so, 1126 * pretend we got a single-step exception. This was pointed out 1127 * by Kumar Gala. -- paulus 1128 */ 1129 static void emulate_single_step(struct pt_regs *regs) 1130 { 1131 if (single_stepping(regs)) 1132 single_step_exception(regs); 1133 } 1134 1135 static inline int __parse_fpscr(unsigned long fpscr) 1136 { 1137 int ret = FPE_FLTUNK; 1138 1139 /* Invalid operation */ 1140 if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX)) 1141 ret = FPE_FLTINV; 1142 1143 /* Overflow */ 1144 else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX)) 1145 ret = FPE_FLTOVF; 1146 1147 /* Underflow */ 1148 else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX)) 1149 ret = FPE_FLTUND; 1150 1151 /* Divide by zero */ 1152 else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX)) 1153 ret = FPE_FLTDIV; 1154 1155 /* Inexact result */ 1156 else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX)) 1157 ret = FPE_FLTRES; 1158 1159 return ret; 1160 } 1161 1162 static void parse_fpe(struct pt_regs *regs) 1163 { 1164 int code = 0; 1165 1166 flush_fp_to_thread(current); 1167 1168 #ifdef CONFIG_PPC_FPU_REGS 1169 code = __parse_fpscr(current->thread.fp_state.fpscr); 1170 #endif 1171 1172 _exception(SIGFPE, regs, code, regs->nip); 1173 } 1174 1175 /* 1176 * Illegal instruction emulation support. Originally written to 1177 * provide the PVR to user applications using the mfspr rd, PVR. 1178 * Return non-zero if we can't emulate, or -EFAULT if the associated 1179 * memory access caused an access fault. Return zero on success. 1180 * 1181 * There are a couple of ways to do this, either "decode" the instruction 1182 * or directly match lots of bits. In this case, matching lots of 1183 * bits is faster and easier. 1184 * 1185 */ 1186 static int emulate_string_inst(struct pt_regs *regs, u32 instword) 1187 { 1188 u8 rT = (instword >> 21) & 0x1f; 1189 u8 rA = (instword >> 16) & 0x1f; 1190 u8 NB_RB = (instword >> 11) & 0x1f; 1191 u32 num_bytes; 1192 unsigned long EA; 1193 int pos = 0; 1194 1195 /* Early out if we are an invalid form of lswx */ 1196 if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX) 1197 if ((rT == rA) || (rT == NB_RB)) 1198 return -EINVAL; 1199 1200 EA = (rA == 0) ? 0 : regs->gpr[rA]; 1201 1202 switch (instword & PPC_INST_STRING_MASK) { 1203 case PPC_INST_LSWX: 1204 case PPC_INST_STSWX: 1205 EA += NB_RB; 1206 num_bytes = regs->xer & 0x7f; 1207 break; 1208 case PPC_INST_LSWI: 1209 case PPC_INST_STSWI: 1210 num_bytes = (NB_RB == 0) ? 32 : NB_RB; 1211 break; 1212 default: 1213 return -EINVAL; 1214 } 1215 1216 while (num_bytes != 0) 1217 { 1218 u8 val; 1219 u32 shift = 8 * (3 - (pos & 0x3)); 1220 1221 /* if process is 32-bit, clear upper 32 bits of EA */ 1222 if ((regs->msr & MSR_64BIT) == 0) 1223 EA &= 0xFFFFFFFF; 1224 1225 switch ((instword & PPC_INST_STRING_MASK)) { 1226 case PPC_INST_LSWX: 1227 case PPC_INST_LSWI: 1228 if (get_user(val, (u8 __user *)EA)) 1229 return -EFAULT; 1230 /* first time updating this reg, 1231 * zero it out */ 1232 if (pos == 0) 1233 regs->gpr[rT] = 0; 1234 regs->gpr[rT] |= val << shift; 1235 break; 1236 case PPC_INST_STSWI: 1237 case PPC_INST_STSWX: 1238 val = regs->gpr[rT] >> shift; 1239 if (put_user(val, (u8 __user *)EA)) 1240 return -EFAULT; 1241 break; 1242 } 1243 /* move EA to next address */ 1244 EA += 1; 1245 num_bytes--; 1246 1247 /* manage our position within the register */ 1248 if (++pos == 4) { 1249 pos = 0; 1250 if (++rT == 32) 1251 rT = 0; 1252 } 1253 } 1254 1255 return 0; 1256 } 1257 1258 static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword) 1259 { 1260 u32 ra,rs; 1261 unsigned long tmp; 1262 1263 ra = (instword >> 16) & 0x1f; 1264 rs = (instword >> 21) & 0x1f; 1265 1266 tmp = regs->gpr[rs]; 1267 tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL); 1268 tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL); 1269 tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL; 1270 regs->gpr[ra] = tmp; 1271 1272 return 0; 1273 } 1274 1275 static int emulate_isel(struct pt_regs *regs, u32 instword) 1276 { 1277 u8 rT = (instword >> 21) & 0x1f; 1278 u8 rA = (instword >> 16) & 0x1f; 1279 u8 rB = (instword >> 11) & 0x1f; 1280 u8 BC = (instword >> 6) & 0x1f; 1281 u8 bit; 1282 unsigned long tmp; 1283 1284 tmp = (rA == 0) ? 0 : regs->gpr[rA]; 1285 bit = (regs->ccr >> (31 - BC)) & 0x1; 1286 1287 regs->gpr[rT] = bit ? tmp : regs->gpr[rB]; 1288 1289 return 0; 1290 } 1291 1292 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1293 static inline bool tm_abort_check(struct pt_regs *regs, int cause) 1294 { 1295 /* If we're emulating a load/store in an active transaction, we cannot 1296 * emulate it as the kernel operates in transaction suspended context. 1297 * We need to abort the transaction. This creates a persistent TM 1298 * abort so tell the user what caused it with a new code. 1299 */ 1300 if (MSR_TM_TRANSACTIONAL(regs->msr)) { 1301 tm_enable(); 1302 tm_abort(cause); 1303 return true; 1304 } 1305 return false; 1306 } 1307 #else 1308 static inline bool tm_abort_check(struct pt_regs *regs, int reason) 1309 { 1310 return false; 1311 } 1312 #endif 1313 1314 static int emulate_instruction(struct pt_regs *regs) 1315 { 1316 u32 instword; 1317 u32 rd; 1318 1319 if (!user_mode(regs)) 1320 return -EINVAL; 1321 1322 if (get_user(instword, (u32 __user *)(regs->nip))) 1323 return -EFAULT; 1324 1325 /* Emulate the mfspr rD, PVR. */ 1326 if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) { 1327 PPC_WARN_EMULATED(mfpvr, regs); 1328 rd = (instword >> 21) & 0x1f; 1329 regs->gpr[rd] = mfspr(SPRN_PVR); 1330 return 0; 1331 } 1332 1333 /* Emulating the dcba insn is just a no-op. */ 1334 if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) { 1335 PPC_WARN_EMULATED(dcba, regs); 1336 return 0; 1337 } 1338 1339 /* Emulate the mcrxr insn. */ 1340 if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) { 1341 int shift = (instword >> 21) & 0x1c; 1342 unsigned long msk = 0xf0000000UL >> shift; 1343 1344 PPC_WARN_EMULATED(mcrxr, regs); 1345 regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk); 1346 regs->xer &= ~0xf0000000UL; 1347 return 0; 1348 } 1349 1350 /* Emulate load/store string insn. */ 1351 if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) { 1352 if (tm_abort_check(regs, 1353 TM_CAUSE_EMULATE | TM_CAUSE_PERSISTENT)) 1354 return -EINVAL; 1355 PPC_WARN_EMULATED(string, regs); 1356 return emulate_string_inst(regs, instword); 1357 } 1358 1359 /* Emulate the popcntb (Population Count Bytes) instruction. */ 1360 if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) { 1361 PPC_WARN_EMULATED(popcntb, regs); 1362 return emulate_popcntb_inst(regs, instword); 1363 } 1364 1365 /* Emulate isel (Integer Select) instruction */ 1366 if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) { 1367 PPC_WARN_EMULATED(isel, regs); 1368 return emulate_isel(regs, instword); 1369 } 1370 1371 /* Emulate sync instruction variants */ 1372 if ((instword & PPC_INST_SYNC_MASK) == PPC_INST_SYNC) { 1373 PPC_WARN_EMULATED(sync, regs); 1374 asm volatile("sync"); 1375 return 0; 1376 } 1377 1378 #ifdef CONFIG_PPC64 1379 /* Emulate the mfspr rD, DSCR. */ 1380 if ((((instword & PPC_INST_MFSPR_DSCR_USER_MASK) == 1381 PPC_INST_MFSPR_DSCR_USER) || 1382 ((instword & PPC_INST_MFSPR_DSCR_MASK) == 1383 PPC_INST_MFSPR_DSCR)) && 1384 cpu_has_feature(CPU_FTR_DSCR)) { 1385 PPC_WARN_EMULATED(mfdscr, regs); 1386 rd = (instword >> 21) & 0x1f; 1387 regs->gpr[rd] = mfspr(SPRN_DSCR); 1388 return 0; 1389 } 1390 /* Emulate the mtspr DSCR, rD. */ 1391 if ((((instword & PPC_INST_MTSPR_DSCR_USER_MASK) == 1392 PPC_INST_MTSPR_DSCR_USER) || 1393 ((instword & PPC_INST_MTSPR_DSCR_MASK) == 1394 PPC_INST_MTSPR_DSCR)) && 1395 cpu_has_feature(CPU_FTR_DSCR)) { 1396 PPC_WARN_EMULATED(mtdscr, regs); 1397 rd = (instword >> 21) & 0x1f; 1398 current->thread.dscr = regs->gpr[rd]; 1399 current->thread.dscr_inherit = 1; 1400 mtspr(SPRN_DSCR, current->thread.dscr); 1401 return 0; 1402 } 1403 #endif 1404 1405 return -EINVAL; 1406 } 1407 1408 int is_valid_bugaddr(unsigned long addr) 1409 { 1410 return is_kernel_addr(addr); 1411 } 1412 1413 #ifdef CONFIG_MATH_EMULATION 1414 static int emulate_math(struct pt_regs *regs) 1415 { 1416 int ret; 1417 1418 ret = do_mathemu(regs); 1419 if (ret >= 0) 1420 PPC_WARN_EMULATED(math, regs); 1421 1422 switch (ret) { 1423 case 0: 1424 emulate_single_step(regs); 1425 return 0; 1426 case 1: { 1427 int code = 0; 1428 code = __parse_fpscr(current->thread.fp_state.fpscr); 1429 _exception(SIGFPE, regs, code, regs->nip); 1430 return 0; 1431 } 1432 case -EFAULT: 1433 _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); 1434 return 0; 1435 } 1436 1437 return -1; 1438 } 1439 #else 1440 static inline int emulate_math(struct pt_regs *regs) { return -1; } 1441 #endif 1442 1443 static void do_program_check(struct pt_regs *regs) 1444 { 1445 unsigned int reason = get_reason(regs); 1446 1447 /* We can now get here via a FP Unavailable exception if the core 1448 * has no FPU, in that case the reason flags will be 0 */ 1449 1450 if (reason & REASON_FP) { 1451 /* IEEE FP exception */ 1452 parse_fpe(regs); 1453 return; 1454 } 1455 if (reason & REASON_TRAP) { 1456 unsigned long bugaddr; 1457 /* Debugger is first in line to stop recursive faults in 1458 * rcu_lock, notify_die, or atomic_notifier_call_chain */ 1459 if (debugger_bpt(regs)) 1460 return; 1461 1462 if (kprobe_handler(regs)) 1463 return; 1464 1465 /* trap exception */ 1466 if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP) 1467 == NOTIFY_STOP) 1468 return; 1469 1470 bugaddr = regs->nip; 1471 /* 1472 * Fixup bugaddr for BUG_ON() in real mode 1473 */ 1474 if (!is_kernel_addr(bugaddr) && !(regs->msr & MSR_IR)) 1475 bugaddr += PAGE_OFFSET; 1476 1477 if (!(regs->msr & MSR_PR) && /* not user-mode */ 1478 report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) { 1479 regs->nip += 4; 1480 return; 1481 } 1482 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip); 1483 return; 1484 } 1485 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1486 if (reason & REASON_TM) { 1487 /* This is a TM "Bad Thing Exception" program check. 1488 * This occurs when: 1489 * - An rfid/hrfid/mtmsrd attempts to cause an illegal 1490 * transition in TM states. 1491 * - A trechkpt is attempted when transactional. 1492 * - A treclaim is attempted when non transactional. 1493 * - A tend is illegally attempted. 1494 * - writing a TM SPR when transactional. 1495 * 1496 * If usermode caused this, it's done something illegal and 1497 * gets a SIGILL slap on the wrist. We call it an illegal 1498 * operand to distinguish from the instruction just being bad 1499 * (e.g. executing a 'tend' on a CPU without TM!); it's an 1500 * illegal /placement/ of a valid instruction. 1501 */ 1502 if (user_mode(regs)) { 1503 _exception(SIGILL, regs, ILL_ILLOPN, regs->nip); 1504 return; 1505 } else { 1506 printk(KERN_EMERG "Unexpected TM Bad Thing exception " 1507 "at %lx (msr 0x%lx) tm_scratch=%llx\n", 1508 regs->nip, regs->msr, get_paca()->tm_scratch); 1509 die("Unrecoverable exception", regs, SIGABRT); 1510 } 1511 } 1512 #endif 1513 1514 /* 1515 * If we took the program check in the kernel skip down to sending a 1516 * SIGILL. The subsequent cases all relate to emulating instructions 1517 * which we should only do for userspace. We also do not want to enable 1518 * interrupts for kernel faults because that might lead to further 1519 * faults, and loose the context of the original exception. 1520 */ 1521 if (!user_mode(regs)) 1522 goto sigill; 1523 1524 interrupt_cond_local_irq_enable(regs); 1525 1526 /* (reason & REASON_ILLEGAL) would be the obvious thing here, 1527 * but there seems to be a hardware bug on the 405GP (RevD) 1528 * that means ESR is sometimes set incorrectly - either to 1529 * ESR_DST (!?) or 0. In the process of chasing this with the 1530 * hardware people - not sure if it can happen on any illegal 1531 * instruction or only on FP instructions, whether there is a 1532 * pattern to occurrences etc. -dgibson 31/Mar/2003 1533 */ 1534 if (!emulate_math(regs)) 1535 return; 1536 1537 /* Try to emulate it if we should. */ 1538 if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) { 1539 switch (emulate_instruction(regs)) { 1540 case 0: 1541 regs->nip += 4; 1542 emulate_single_step(regs); 1543 return; 1544 case -EFAULT: 1545 _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); 1546 return; 1547 } 1548 } 1549 1550 sigill: 1551 if (reason & REASON_PRIVILEGED) 1552 _exception(SIGILL, regs, ILL_PRVOPC, regs->nip); 1553 else 1554 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); 1555 1556 } 1557 1558 DEFINE_INTERRUPT_HANDLER(program_check_exception) 1559 { 1560 do_program_check(regs); 1561 } 1562 1563 /* 1564 * This occurs when running in hypervisor mode on POWER6 or later 1565 * and an illegal instruction is encountered. 1566 */ 1567 DEFINE_INTERRUPT_HANDLER(emulation_assist_interrupt) 1568 { 1569 regs->msr |= REASON_ILLEGAL; 1570 do_program_check(regs); 1571 } 1572 1573 DEFINE_INTERRUPT_HANDLER(alignment_exception) 1574 { 1575 int sig, code, fixed = 0; 1576 unsigned long reason; 1577 1578 interrupt_cond_local_irq_enable(regs); 1579 1580 reason = get_reason(regs); 1581 if (reason & REASON_BOUNDARY) { 1582 sig = SIGBUS; 1583 code = BUS_ADRALN; 1584 goto bad; 1585 } 1586 1587 if (tm_abort_check(regs, TM_CAUSE_ALIGNMENT | TM_CAUSE_PERSISTENT)) 1588 return; 1589 1590 /* we don't implement logging of alignment exceptions */ 1591 if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS)) 1592 fixed = fix_alignment(regs); 1593 1594 if (fixed == 1) { 1595 /* skip over emulated instruction */ 1596 regs->nip += inst_length(reason); 1597 emulate_single_step(regs); 1598 return; 1599 } 1600 1601 /* Operand address was bad */ 1602 if (fixed == -EFAULT) { 1603 sig = SIGSEGV; 1604 code = SEGV_ACCERR; 1605 } else { 1606 sig = SIGBUS; 1607 code = BUS_ADRALN; 1608 } 1609 bad: 1610 if (user_mode(regs)) 1611 _exception(sig, regs, code, regs->dar); 1612 else 1613 bad_page_fault(regs, sig); 1614 } 1615 1616 DEFINE_INTERRUPT_HANDLER(stack_overflow_exception) 1617 { 1618 die("Kernel stack overflow", regs, SIGSEGV); 1619 } 1620 1621 DEFINE_INTERRUPT_HANDLER(kernel_fp_unavailable_exception) 1622 { 1623 printk(KERN_EMERG "Unrecoverable FP Unavailable Exception " 1624 "%lx at %lx\n", regs->trap, regs->nip); 1625 die("Unrecoverable FP Unavailable Exception", regs, SIGABRT); 1626 } 1627 1628 DEFINE_INTERRUPT_HANDLER(altivec_unavailable_exception) 1629 { 1630 if (user_mode(regs)) { 1631 /* A user program has executed an altivec instruction, 1632 but this kernel doesn't support altivec. */ 1633 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); 1634 return; 1635 } 1636 1637 printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception " 1638 "%lx at %lx\n", regs->trap, regs->nip); 1639 die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT); 1640 } 1641 1642 DEFINE_INTERRUPT_HANDLER(vsx_unavailable_exception) 1643 { 1644 if (user_mode(regs)) { 1645 /* A user program has executed an vsx instruction, 1646 but this kernel doesn't support vsx. */ 1647 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); 1648 return; 1649 } 1650 1651 printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception " 1652 "%lx at %lx\n", regs->trap, regs->nip); 1653 die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT); 1654 } 1655 1656 #ifdef CONFIG_PPC64 1657 static void tm_unavailable(struct pt_regs *regs) 1658 { 1659 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1660 if (user_mode(regs)) { 1661 current->thread.load_tm++; 1662 regs->msr |= MSR_TM; 1663 tm_enable(); 1664 tm_restore_sprs(¤t->thread); 1665 return; 1666 } 1667 #endif 1668 pr_emerg("Unrecoverable TM Unavailable Exception " 1669 "%lx at %lx\n", regs->trap, regs->nip); 1670 die("Unrecoverable TM Unavailable Exception", regs, SIGABRT); 1671 } 1672 1673 DEFINE_INTERRUPT_HANDLER(facility_unavailable_exception) 1674 { 1675 static char *facility_strings[] = { 1676 [FSCR_FP_LG] = "FPU", 1677 [FSCR_VECVSX_LG] = "VMX/VSX", 1678 [FSCR_DSCR_LG] = "DSCR", 1679 [FSCR_PM_LG] = "PMU SPRs", 1680 [FSCR_BHRB_LG] = "BHRB", 1681 [FSCR_TM_LG] = "TM", 1682 [FSCR_EBB_LG] = "EBB", 1683 [FSCR_TAR_LG] = "TAR", 1684 [FSCR_MSGP_LG] = "MSGP", 1685 [FSCR_SCV_LG] = "SCV", 1686 [FSCR_PREFIX_LG] = "PREFIX", 1687 }; 1688 char *facility = "unknown"; 1689 u64 value; 1690 u32 instword, rd; 1691 u8 status; 1692 bool hv; 1693 1694 hv = (TRAP(regs) == INTERRUPT_H_FAC_UNAVAIL); 1695 if (hv) 1696 value = mfspr(SPRN_HFSCR); 1697 else 1698 value = mfspr(SPRN_FSCR); 1699 1700 status = value >> 56; 1701 if ((hv || status >= 2) && 1702 (status < ARRAY_SIZE(facility_strings)) && 1703 facility_strings[status]) 1704 facility = facility_strings[status]; 1705 1706 /* We should not have taken this interrupt in kernel */ 1707 if (!user_mode(regs)) { 1708 pr_emerg("Facility '%s' unavailable (%d) exception in kernel mode at %lx\n", 1709 facility, status, regs->nip); 1710 die("Unexpected facility unavailable exception", regs, SIGABRT); 1711 } 1712 1713 interrupt_cond_local_irq_enable(regs); 1714 1715 if (status == FSCR_DSCR_LG) { 1716 /* 1717 * User is accessing the DSCR register using the problem 1718 * state only SPR number (0x03) either through a mfspr or 1719 * a mtspr instruction. If it is a write attempt through 1720 * a mtspr, then we set the inherit bit. This also allows 1721 * the user to write or read the register directly in the 1722 * future by setting via the FSCR DSCR bit. But in case it 1723 * is a read DSCR attempt through a mfspr instruction, we 1724 * just emulate the instruction instead. This code path will 1725 * always emulate all the mfspr instructions till the user 1726 * has attempted at least one mtspr instruction. This way it 1727 * preserves the same behaviour when the user is accessing 1728 * the DSCR through privilege level only SPR number (0x11) 1729 * which is emulated through illegal instruction exception. 1730 * We always leave HFSCR DSCR set. 1731 */ 1732 if (get_user(instword, (u32 __user *)(regs->nip))) { 1733 pr_err("Failed to fetch the user instruction\n"); 1734 return; 1735 } 1736 1737 /* Write into DSCR (mtspr 0x03, RS) */ 1738 if ((instword & PPC_INST_MTSPR_DSCR_USER_MASK) 1739 == PPC_INST_MTSPR_DSCR_USER) { 1740 rd = (instword >> 21) & 0x1f; 1741 current->thread.dscr = regs->gpr[rd]; 1742 current->thread.dscr_inherit = 1; 1743 current->thread.fscr |= FSCR_DSCR; 1744 mtspr(SPRN_FSCR, current->thread.fscr); 1745 } 1746 1747 /* Read from DSCR (mfspr RT, 0x03) */ 1748 if ((instword & PPC_INST_MFSPR_DSCR_USER_MASK) 1749 == PPC_INST_MFSPR_DSCR_USER) { 1750 if (emulate_instruction(regs)) { 1751 pr_err("DSCR based mfspr emulation failed\n"); 1752 return; 1753 } 1754 regs->nip += 4; 1755 emulate_single_step(regs); 1756 } 1757 return; 1758 } 1759 1760 if (status == FSCR_TM_LG) { 1761 /* 1762 * If we're here then the hardware is TM aware because it 1763 * generated an exception with FSRM_TM set. 1764 * 1765 * If cpu_has_feature(CPU_FTR_TM) is false, then either firmware 1766 * told us not to do TM, or the kernel is not built with TM 1767 * support. 1768 * 1769 * If both of those things are true, then userspace can spam the 1770 * console by triggering the printk() below just by continually 1771 * doing tbegin (or any TM instruction). So in that case just 1772 * send the process a SIGILL immediately. 1773 */ 1774 if (!cpu_has_feature(CPU_FTR_TM)) 1775 goto out; 1776 1777 tm_unavailable(regs); 1778 return; 1779 } 1780 1781 pr_err_ratelimited("%sFacility '%s' unavailable (%d), exception at 0x%lx, MSR=%lx\n", 1782 hv ? "Hypervisor " : "", facility, status, regs->nip, regs->msr); 1783 1784 out: 1785 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); 1786 } 1787 #endif 1788 1789 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1790 1791 DEFINE_INTERRUPT_HANDLER(fp_unavailable_tm) 1792 { 1793 /* Note: This does not handle any kind of FP laziness. */ 1794 1795 TM_DEBUG("FP Unavailable trap whilst transactional at 0x%lx, MSR=%lx\n", 1796 regs->nip, regs->msr); 1797 1798 /* We can only have got here if the task started using FP after 1799 * beginning the transaction. So, the transactional regs are just a 1800 * copy of the checkpointed ones. But, we still need to recheckpoint 1801 * as we're enabling FP for the process; it will return, abort the 1802 * transaction, and probably retry but now with FP enabled. So the 1803 * checkpointed FP registers need to be loaded. 1804 */ 1805 tm_reclaim_current(TM_CAUSE_FAC_UNAV); 1806 1807 /* 1808 * Reclaim initially saved out bogus (lazy) FPRs to ckfp_state, and 1809 * then it was overwrite by the thr->fp_state by tm_reclaim_thread(). 1810 * 1811 * At this point, ck{fp,vr}_state contains the exact values we want to 1812 * recheckpoint. 1813 */ 1814 1815 /* Enable FP for the task: */ 1816 current->thread.load_fp = 1; 1817 1818 /* 1819 * Recheckpoint all the checkpointed ckpt, ck{fp, vr}_state registers. 1820 */ 1821 tm_recheckpoint(¤t->thread); 1822 } 1823 1824 DEFINE_INTERRUPT_HANDLER(altivec_unavailable_tm) 1825 { 1826 /* See the comments in fp_unavailable_tm(). This function operates 1827 * the same way. 1828 */ 1829 1830 TM_DEBUG("Vector Unavailable trap whilst transactional at 0x%lx," 1831 "MSR=%lx\n", 1832 regs->nip, regs->msr); 1833 tm_reclaim_current(TM_CAUSE_FAC_UNAV); 1834 current->thread.load_vec = 1; 1835 tm_recheckpoint(¤t->thread); 1836 current->thread.used_vr = 1; 1837 } 1838 1839 DEFINE_INTERRUPT_HANDLER(vsx_unavailable_tm) 1840 { 1841 /* See the comments in fp_unavailable_tm(). This works similarly, 1842 * though we're loading both FP and VEC registers in here. 1843 * 1844 * If FP isn't in use, load FP regs. If VEC isn't in use, load VEC 1845 * regs. Either way, set MSR_VSX. 1846 */ 1847 1848 TM_DEBUG("VSX Unavailable trap whilst transactional at 0x%lx," 1849 "MSR=%lx\n", 1850 regs->nip, regs->msr); 1851 1852 current->thread.used_vsr = 1; 1853 1854 /* This reclaims FP and/or VR regs if they're already enabled */ 1855 tm_reclaim_current(TM_CAUSE_FAC_UNAV); 1856 1857 current->thread.load_vec = 1; 1858 current->thread.load_fp = 1; 1859 1860 tm_recheckpoint(¤t->thread); 1861 } 1862 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ 1863 1864 #ifdef CONFIG_PPC64 1865 DECLARE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi); 1866 DEFINE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi) 1867 { 1868 __this_cpu_inc(irq_stat.pmu_irqs); 1869 1870 perf_irq(regs); 1871 1872 return 0; 1873 } 1874 #endif 1875 1876 DECLARE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async); 1877 DEFINE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async) 1878 { 1879 __this_cpu_inc(irq_stat.pmu_irqs); 1880 1881 perf_irq(regs); 1882 } 1883 1884 DEFINE_INTERRUPT_HANDLER_RAW(performance_monitor_exception) 1885 { 1886 /* 1887 * On 64-bit, if perf interrupts hit in a local_irq_disable 1888 * (soft-masked) region, we consider them as NMIs. This is required to 1889 * prevent hash faults on user addresses when reading callchains (and 1890 * looks better from an irq tracing perspective). 1891 */ 1892 if (IS_ENABLED(CONFIG_PPC64) && unlikely(arch_irq_disabled_regs(regs))) 1893 performance_monitor_exception_nmi(regs); 1894 else 1895 performance_monitor_exception_async(regs); 1896 1897 return 0; 1898 } 1899 1900 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 1901 static void handle_debug(struct pt_regs *regs, unsigned long debug_status) 1902 { 1903 int changed = 0; 1904 /* 1905 * Determine the cause of the debug event, clear the 1906 * event flags and send a trap to the handler. Torez 1907 */ 1908 if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) { 1909 dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W); 1910 #ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE 1911 current->thread.debug.dbcr2 &= ~DBCR2_DAC12MODE; 1912 #endif 1913 do_send_trap(regs, mfspr(SPRN_DAC1), debug_status, 1914 5); 1915 changed |= 0x01; 1916 } else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) { 1917 dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W); 1918 do_send_trap(regs, mfspr(SPRN_DAC2), debug_status, 1919 6); 1920 changed |= 0x01; 1921 } else if (debug_status & DBSR_IAC1) { 1922 current->thread.debug.dbcr0 &= ~DBCR0_IAC1; 1923 dbcr_iac_range(current) &= ~DBCR_IAC12MODE; 1924 do_send_trap(regs, mfspr(SPRN_IAC1), debug_status, 1925 1); 1926 changed |= 0x01; 1927 } else if (debug_status & DBSR_IAC2) { 1928 current->thread.debug.dbcr0 &= ~DBCR0_IAC2; 1929 do_send_trap(regs, mfspr(SPRN_IAC2), debug_status, 1930 2); 1931 changed |= 0x01; 1932 } else if (debug_status & DBSR_IAC3) { 1933 current->thread.debug.dbcr0 &= ~DBCR0_IAC3; 1934 dbcr_iac_range(current) &= ~DBCR_IAC34MODE; 1935 do_send_trap(regs, mfspr(SPRN_IAC3), debug_status, 1936 3); 1937 changed |= 0x01; 1938 } else if (debug_status & DBSR_IAC4) { 1939 current->thread.debug.dbcr0 &= ~DBCR0_IAC4; 1940 do_send_trap(regs, mfspr(SPRN_IAC4), debug_status, 1941 4); 1942 changed |= 0x01; 1943 } 1944 /* 1945 * At the point this routine was called, the MSR(DE) was turned off. 1946 * Check all other debug flags and see if that bit needs to be turned 1947 * back on or not. 1948 */ 1949 if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0, 1950 current->thread.debug.dbcr1)) 1951 regs->msr |= MSR_DE; 1952 else 1953 /* Make sure the IDM flag is off */ 1954 current->thread.debug.dbcr0 &= ~DBCR0_IDM; 1955 1956 if (changed & 0x01) 1957 mtspr(SPRN_DBCR0, current->thread.debug.dbcr0); 1958 } 1959 1960 DEFINE_INTERRUPT_HANDLER(DebugException) 1961 { 1962 unsigned long debug_status = regs->dsisr; 1963 1964 current->thread.debug.dbsr = debug_status; 1965 1966 /* Hack alert: On BookE, Branch Taken stops on the branch itself, while 1967 * on server, it stops on the target of the branch. In order to simulate 1968 * the server behaviour, we thus restart right away with a single step 1969 * instead of stopping here when hitting a BT 1970 */ 1971 if (debug_status & DBSR_BT) { 1972 regs->msr &= ~MSR_DE; 1973 1974 /* Disable BT */ 1975 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT); 1976 /* Clear the BT event */ 1977 mtspr(SPRN_DBSR, DBSR_BT); 1978 1979 /* Do the single step trick only when coming from userspace */ 1980 if (user_mode(regs)) { 1981 current->thread.debug.dbcr0 &= ~DBCR0_BT; 1982 current->thread.debug.dbcr0 |= DBCR0_IDM | DBCR0_IC; 1983 regs->msr |= MSR_DE; 1984 return; 1985 } 1986 1987 if (kprobe_post_handler(regs)) 1988 return; 1989 1990 if (notify_die(DIE_SSTEP, "block_step", regs, 5, 1991 5, SIGTRAP) == NOTIFY_STOP) { 1992 return; 1993 } 1994 if (debugger_sstep(regs)) 1995 return; 1996 } else if (debug_status & DBSR_IC) { /* Instruction complete */ 1997 regs->msr &= ~MSR_DE; 1998 1999 /* Disable instruction completion */ 2000 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC); 2001 /* Clear the instruction completion event */ 2002 mtspr(SPRN_DBSR, DBSR_IC); 2003 2004 if (kprobe_post_handler(regs)) 2005 return; 2006 2007 if (notify_die(DIE_SSTEP, "single_step", regs, 5, 2008 5, SIGTRAP) == NOTIFY_STOP) { 2009 return; 2010 } 2011 2012 if (debugger_sstep(regs)) 2013 return; 2014 2015 if (user_mode(regs)) { 2016 current->thread.debug.dbcr0 &= ~DBCR0_IC; 2017 if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0, 2018 current->thread.debug.dbcr1)) 2019 regs->msr |= MSR_DE; 2020 else 2021 /* Make sure the IDM bit is off */ 2022 current->thread.debug.dbcr0 &= ~DBCR0_IDM; 2023 } 2024 2025 _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip); 2026 } else 2027 handle_debug(regs, debug_status); 2028 } 2029 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ 2030 2031 #ifdef CONFIG_ALTIVEC 2032 DEFINE_INTERRUPT_HANDLER(altivec_assist_exception) 2033 { 2034 int err; 2035 2036 if (!user_mode(regs)) { 2037 printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode" 2038 " at %lx\n", regs->nip); 2039 die("Kernel VMX/Altivec assist exception", regs, SIGILL); 2040 } 2041 2042 flush_altivec_to_thread(current); 2043 2044 PPC_WARN_EMULATED(altivec, regs); 2045 err = emulate_altivec(regs); 2046 if (err == 0) { 2047 regs->nip += 4; /* skip emulated instruction */ 2048 emulate_single_step(regs); 2049 return; 2050 } 2051 2052 if (err == -EFAULT) { 2053 /* got an error reading the instruction */ 2054 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); 2055 } else { 2056 /* didn't recognize the instruction */ 2057 /* XXX quick hack for now: set the non-Java bit in the VSCR */ 2058 printk_ratelimited(KERN_ERR "Unrecognized altivec instruction " 2059 "in %s at %lx\n", current->comm, regs->nip); 2060 current->thread.vr_state.vscr.u[3] |= 0x10000; 2061 } 2062 } 2063 #endif /* CONFIG_ALTIVEC */ 2064 2065 #ifdef CONFIG_FSL_BOOKE 2066 DEFINE_INTERRUPT_HANDLER(CacheLockingException) 2067 { 2068 unsigned long error_code = regs->dsisr; 2069 2070 /* We treat cache locking instructions from the user 2071 * as priv ops, in the future we could try to do 2072 * something smarter 2073 */ 2074 if (error_code & (ESR_DLK|ESR_ILK)) 2075 _exception(SIGILL, regs, ILL_PRVOPC, regs->nip); 2076 return; 2077 } 2078 #endif /* CONFIG_FSL_BOOKE */ 2079 2080 #ifdef CONFIG_SPE 2081 DEFINE_INTERRUPT_HANDLER(SPEFloatingPointException) 2082 { 2083 extern int do_spe_mathemu(struct pt_regs *regs); 2084 unsigned long spefscr; 2085 int fpexc_mode; 2086 int code = FPE_FLTUNK; 2087 int err; 2088 2089 interrupt_cond_local_irq_enable(regs); 2090 2091 flush_spe_to_thread(current); 2092 2093 spefscr = current->thread.spefscr; 2094 fpexc_mode = current->thread.fpexc_mode; 2095 2096 if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) { 2097 code = FPE_FLTOVF; 2098 } 2099 else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) { 2100 code = FPE_FLTUND; 2101 } 2102 else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV)) 2103 code = FPE_FLTDIV; 2104 else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) { 2105 code = FPE_FLTINV; 2106 } 2107 else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES)) 2108 code = FPE_FLTRES; 2109 2110 err = do_spe_mathemu(regs); 2111 if (err == 0) { 2112 regs->nip += 4; /* skip emulated instruction */ 2113 emulate_single_step(regs); 2114 return; 2115 } 2116 2117 if (err == -EFAULT) { 2118 /* got an error reading the instruction */ 2119 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); 2120 } else if (err == -EINVAL) { 2121 /* didn't recognize the instruction */ 2122 printk(KERN_ERR "unrecognized spe instruction " 2123 "in %s at %lx\n", current->comm, regs->nip); 2124 } else { 2125 _exception(SIGFPE, regs, code, regs->nip); 2126 } 2127 2128 return; 2129 } 2130 2131 DEFINE_INTERRUPT_HANDLER(SPEFloatingPointRoundException) 2132 { 2133 extern int speround_handler(struct pt_regs *regs); 2134 int err; 2135 2136 interrupt_cond_local_irq_enable(regs); 2137 2138 preempt_disable(); 2139 if (regs->msr & MSR_SPE) 2140 giveup_spe(current); 2141 preempt_enable(); 2142 2143 regs->nip -= 4; 2144 err = speround_handler(regs); 2145 if (err == 0) { 2146 regs->nip += 4; /* skip emulated instruction */ 2147 emulate_single_step(regs); 2148 return; 2149 } 2150 2151 if (err == -EFAULT) { 2152 /* got an error reading the instruction */ 2153 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); 2154 } else if (err == -EINVAL) { 2155 /* didn't recognize the instruction */ 2156 printk(KERN_ERR "unrecognized spe instruction " 2157 "in %s at %lx\n", current->comm, regs->nip); 2158 } else { 2159 _exception(SIGFPE, regs, FPE_FLTUNK, regs->nip); 2160 return; 2161 } 2162 } 2163 #endif 2164 2165 /* 2166 * We enter here if we get an unrecoverable exception, that is, one 2167 * that happened at a point where the RI (recoverable interrupt) bit 2168 * in the MSR is 0. This indicates that SRR0/1 are live, and that 2169 * we therefore lost state by taking this exception. 2170 */ 2171 void __noreturn unrecoverable_exception(struct pt_regs *regs) 2172 { 2173 pr_emerg("Unrecoverable exception %lx at %lx (msr=%lx)\n", 2174 regs->trap, regs->nip, regs->msr); 2175 die("Unrecoverable exception", regs, SIGABRT); 2176 /* die() should not return */ 2177 for (;;) 2178 ; 2179 } 2180 2181 #if defined(CONFIG_BOOKE_WDT) || defined(CONFIG_40x) 2182 /* 2183 * Default handler for a Watchdog exception, 2184 * spins until a reboot occurs 2185 */ 2186 void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs) 2187 { 2188 /* Generic WatchdogHandler, implement your own */ 2189 mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE)); 2190 return; 2191 } 2192 2193 DEFINE_INTERRUPT_HANDLER_NMI(WatchdogException) 2194 { 2195 printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n"); 2196 WatchdogHandler(regs); 2197 return 0; 2198 } 2199 #endif 2200 2201 /* 2202 * We enter here if we discover during exception entry that we are 2203 * running in supervisor mode with a userspace value in the stack pointer. 2204 */ 2205 DEFINE_INTERRUPT_HANDLER(kernel_bad_stack) 2206 { 2207 printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n", 2208 regs->gpr[1], regs->nip); 2209 die("Bad kernel stack pointer", regs, SIGABRT); 2210 } 2211 2212 void __init trap_init(void) 2213 { 2214 } 2215 2216 2217 #ifdef CONFIG_PPC_EMULATED_STATS 2218 2219 #define WARN_EMULATED_SETUP(type) .type = { .name = #type } 2220 2221 struct ppc_emulated ppc_emulated = { 2222 #ifdef CONFIG_ALTIVEC 2223 WARN_EMULATED_SETUP(altivec), 2224 #endif 2225 WARN_EMULATED_SETUP(dcba), 2226 WARN_EMULATED_SETUP(dcbz), 2227 WARN_EMULATED_SETUP(fp_pair), 2228 WARN_EMULATED_SETUP(isel), 2229 WARN_EMULATED_SETUP(mcrxr), 2230 WARN_EMULATED_SETUP(mfpvr), 2231 WARN_EMULATED_SETUP(multiple), 2232 WARN_EMULATED_SETUP(popcntb), 2233 WARN_EMULATED_SETUP(spe), 2234 WARN_EMULATED_SETUP(string), 2235 WARN_EMULATED_SETUP(sync), 2236 WARN_EMULATED_SETUP(unaligned), 2237 #ifdef CONFIG_MATH_EMULATION 2238 WARN_EMULATED_SETUP(math), 2239 #endif 2240 #ifdef CONFIG_VSX 2241 WARN_EMULATED_SETUP(vsx), 2242 #endif 2243 #ifdef CONFIG_PPC64 2244 WARN_EMULATED_SETUP(mfdscr), 2245 WARN_EMULATED_SETUP(mtdscr), 2246 WARN_EMULATED_SETUP(lq_stq), 2247 WARN_EMULATED_SETUP(lxvw4x), 2248 WARN_EMULATED_SETUP(lxvh8x), 2249 WARN_EMULATED_SETUP(lxvd2x), 2250 WARN_EMULATED_SETUP(lxvb16x), 2251 #endif 2252 }; 2253 2254 u32 ppc_warn_emulated; 2255 2256 void ppc_warn_emulated_print(const char *type) 2257 { 2258 pr_warn_ratelimited("%s used emulated %s instruction\n", current->comm, 2259 type); 2260 } 2261 2262 static int __init ppc_warn_emulated_init(void) 2263 { 2264 struct dentry *dir; 2265 unsigned int i; 2266 struct ppc_emulated_entry *entries = (void *)&ppc_emulated; 2267 2268 dir = debugfs_create_dir("emulated_instructions", 2269 powerpc_debugfs_root); 2270 2271 debugfs_create_u32("do_warn", 0644, dir, &ppc_warn_emulated); 2272 2273 for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) 2274 debugfs_create_u32(entries[i].name, 0644, dir, 2275 (u32 *)&entries[i].val.counter); 2276 2277 return 0; 2278 } 2279 2280 device_initcall(ppc_warn_emulated_init); 2281 2282 #endif /* CONFIG_PPC_EMULATED_STATS */ 2283