// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * Copyright 2007-2010 Freescale Semiconductor, Inc. * * Modified by Cort Dougan (cort@cs.nmt.edu) * and Paul Mackerras (paulus@samba.org) */ /* * This file handles the architecture-dependent parts of hardware exceptions */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* print_modules */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_PMAC_BACKLIGHT #include #endif #ifdef CONFIG_PPC64 #include #include #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC_CORE) int (*__debugger)(struct pt_regs *regs) __read_mostly; int (*__debugger_ipi)(struct pt_regs *regs) __read_mostly; int (*__debugger_bpt)(struct pt_regs *regs) __read_mostly; int (*__debugger_sstep)(struct pt_regs *regs) __read_mostly; int (*__debugger_iabr_match)(struct pt_regs *regs) __read_mostly; int (*__debugger_break_match)(struct pt_regs *regs) __read_mostly; int (*__debugger_fault_handler)(struct pt_regs *regs) __read_mostly; EXPORT_SYMBOL(__debugger); EXPORT_SYMBOL(__debugger_ipi); EXPORT_SYMBOL(__debugger_bpt); EXPORT_SYMBOL(__debugger_sstep); EXPORT_SYMBOL(__debugger_iabr_match); EXPORT_SYMBOL(__debugger_break_match); EXPORT_SYMBOL(__debugger_fault_handler); #endif /* Transactional Memory trap debug */ #ifdef TM_DEBUG_SW #define TM_DEBUG(x...) printk(KERN_INFO x) #else #define TM_DEBUG(x...) do { } while(0) #endif static const char *signame(int signr) { switch (signr) { case SIGBUS: return "bus error"; case SIGFPE: return "floating point exception"; case SIGILL: return "illegal instruction"; case SIGSEGV: return "segfault"; case SIGTRAP: return "unhandled trap"; } return "unknown signal"; } /* * Trap & Exception support */ #ifdef CONFIG_PMAC_BACKLIGHT static void pmac_backlight_unblank(void) { mutex_lock(&pmac_backlight_mutex); if (pmac_backlight) { struct backlight_properties *props; props = &pmac_backlight->props; props->brightness = props->max_brightness; props->power = FB_BLANK_UNBLANK; backlight_update_status(pmac_backlight); } mutex_unlock(&pmac_backlight_mutex); } #else static inline void pmac_backlight_unblank(void) { } #endif /* * If oops/die is expected to crash the machine, return true here. * * This should not be expected to be 100% accurate, there may be * notifiers registered or other unexpected conditions that may bring * down the kernel. Or if the current process in the kernel is holding * locks or has other critical state, the kernel may become effectively * unusable anyway. */ bool die_will_crash(void) { if (should_fadump_crash()) return true; if (kexec_should_crash(current)) return true; if (in_interrupt() || panic_on_oops || !current->pid || is_global_init(current)) return true; return false; } static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; static int die_owner = -1; static unsigned int die_nest_count; static int die_counter; extern void panic_flush_kmsg_start(void) { /* * These are mostly taken from kernel/panic.c, but tries to do * relatively minimal work. Don't use delay functions (TB may * be broken), don't crash dump (need to set a firmware log), * don't run notifiers. We do want to get some information to * Linux console. */ console_verbose(); bust_spinlocks(1); } extern void panic_flush_kmsg_end(void) { printk_safe_flush_on_panic(); kmsg_dump(KMSG_DUMP_PANIC); bust_spinlocks(0); debug_locks_off(); console_flush_on_panic(CONSOLE_FLUSH_PENDING); } static unsigned long oops_begin(struct pt_regs *regs) { int cpu; unsigned long flags; oops_enter(); /* racy, but better than risking deadlock. */ raw_local_irq_save(flags); cpu = smp_processor_id(); if (!arch_spin_trylock(&die_lock)) { if (cpu == die_owner) /* nested oops. should stop eventually */; else arch_spin_lock(&die_lock); } die_nest_count++; die_owner = cpu; console_verbose(); bust_spinlocks(1); if (machine_is(powermac)) pmac_backlight_unblank(); return flags; } NOKPROBE_SYMBOL(oops_begin); static void oops_end(unsigned long flags, struct pt_regs *regs, int signr) { bust_spinlocks(0); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); die_nest_count--; oops_exit(); printk("\n"); if (!die_nest_count) { /* Nest count reaches zero, release the lock. */ die_owner = -1; arch_spin_unlock(&die_lock); } raw_local_irq_restore(flags); /* * system_reset_excption handles debugger, crash dump, panic, for 0x100 */ if (TRAP(regs) == 0x100) return; crash_fadump(regs, "die oops"); if (kexec_should_crash(current)) crash_kexec(regs); if (!signr) return; /* * While our oops output is serialised by a spinlock, output * from panic() called below can race and corrupt it. If we * know we are going to panic, delay for 1 second so we have a * chance to get clean backtraces from all CPUs that are oopsing. */ if (in_interrupt() || panic_on_oops || !current->pid || is_global_init(current)) { mdelay(MSEC_PER_SEC); } if (panic_on_oops) panic("Fatal exception"); do_exit(signr); } NOKPROBE_SYMBOL(oops_end); static char *get_mmu_str(void) { if (early_radix_enabled()) return " MMU=Radix"; if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) return " MMU=Hash"; return ""; } static int __die(const char *str, struct pt_regs *regs, long err) { printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s %s\n", IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE", PAGE_SIZE / 1024, get_mmu_str(), IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "", IS_ENABLED(CONFIG_SMP) ? " SMP" : "", IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "", debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "", IS_ENABLED(CONFIG_NUMA) ? " NUMA" : "", ppc_md.name ? ppc_md.name : ""); if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP) return 1; print_modules(); show_regs(regs); return 0; } NOKPROBE_SYMBOL(__die); void die(const char *str, struct pt_regs *regs, long err) { unsigned long flags; /* * system_reset_excption handles debugger, crash dump, panic, for 0x100 */ if (TRAP(regs) != 0x100) { if (debugger(regs)) return; } flags = oops_begin(regs); if (__die(str, regs, err)) err = 0; oops_end(flags, regs, err); } NOKPROBE_SYMBOL(die); void user_single_step_report(struct pt_regs *regs) { force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)regs->nip); } static void show_signal_msg(int signr, struct pt_regs *regs, int code, unsigned long addr) { static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); if (!show_unhandled_signals) return; if (!unhandled_signal(current, signr)) return; if (!__ratelimit(&rs)) return; pr_info("%s[%d]: %s (%d) at %lx nip %lx lr %lx code %x", current->comm, current->pid, signame(signr), signr, addr, regs->nip, regs->link, code); print_vma_addr(KERN_CONT " in ", regs->nip); pr_cont("\n"); show_user_instructions(regs); } static bool exception_common(int signr, struct pt_regs *regs, int code, unsigned long addr) { if (!user_mode(regs)) { die("Exception in kernel mode", regs, signr); return false; } show_signal_msg(signr, regs, code, addr); if (arch_irqs_disabled() && !arch_irq_disabled_regs(regs)) local_irq_enable(); current->thread.trap_nr = code; /* * Save all the pkey registers AMR/IAMR/UAMOR. Eg: Core dumps need * to capture the content, if the task gets killed. */ thread_pkey_regs_save(¤t->thread); return true; } void _exception_pkey(struct pt_regs *regs, unsigned long addr, int key) { if (!exception_common(SIGSEGV, regs, SEGV_PKUERR, addr)) return; force_sig_pkuerr((void __user *) addr, key); } void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) { if (!exception_common(signr, regs, code, addr)) return; force_sig_fault(signr, code, (void __user *)addr); } /* * The interrupt architecture has a quirk in that the HV interrupts excluding * the NMIs (0x100 and 0x200) do not clear MSR[RI] at entry. The first thing * that an interrupt handler must do is save off a GPR into a scratch register, * and all interrupts on POWERNV (HV=1) use the HSPRG1 register as scratch. * Therefore an NMI can clobber an HV interrupt's live HSPRG1 without noticing * that it is non-reentrant, which leads to random data corruption. * * The solution is for NMI interrupts in HV mode to check if they originated * from these critical HV interrupt regions. If so, then mark them not * recoverable. * * An alternative would be for HV NMIs to use SPRG for scratch to avoid the * HSPRG1 clobber, however this would cause guest SPRG to be clobbered. Linux * guests should always have MSR[RI]=0 when its scratch SPRG is in use, so * that would work. However any other guest OS that may have the SPRG live * and MSR[RI]=1 could encounter silent corruption. * * Builds that do not support KVM could take this second option to increase * the recoverability of NMIs. */ void hv_nmi_check_nonrecoverable(struct pt_regs *regs) { #ifdef CONFIG_PPC_POWERNV unsigned long kbase = (unsigned long)_stext; unsigned long nip = regs->nip; if (!(regs->msr & MSR_RI)) return; if (!(regs->msr & MSR_HV)) return; if (regs->msr & MSR_PR) return; /* * Now test if the interrupt has hit a range that may be using * HSPRG1 without having RI=0 (i.e., an HSRR interrupt). The * problem ranges all run un-relocated. Test real and virt modes * at the same time by droping the high bit of the nip (virt mode * entry points still have the +0x4000 offset). */ nip &= ~0xc000000000000000ULL; if ((nip >= 0x500 && nip < 0x600) || (nip >= 0x4500 && nip < 0x4600)) goto nonrecoverable; if ((nip >= 0x980 && nip < 0xa00) || (nip >= 0x4980 && nip < 0x4a00)) goto nonrecoverable; if ((nip >= 0xe00 && nip < 0xec0) || (nip >= 0x4e00 && nip < 0x4ec0)) goto nonrecoverable; if ((nip >= 0xf80 && nip < 0xfa0) || (nip >= 0x4f80 && nip < 0x4fa0)) goto nonrecoverable; /* Trampoline code runs un-relocated so subtract kbase. */ if (nip >= (unsigned long)(start_real_trampolines - kbase) && nip < (unsigned long)(end_real_trampolines - kbase)) goto nonrecoverable; if (nip >= (unsigned long)(start_virt_trampolines - kbase) && nip < (unsigned long)(end_virt_trampolines - kbase)) goto nonrecoverable; return; nonrecoverable: regs->msr &= ~MSR_RI; #endif } void system_reset_exception(struct pt_regs *regs) { unsigned long hsrr0, hsrr1; bool nested = in_nmi(); bool saved_hsrrs = false; u8 ftrace_enabled = this_cpu_get_ftrace_enabled(); this_cpu_set_ftrace_enabled(0); /* * Avoid crashes in case of nested NMI exceptions. Recoverability * is determined by RI and in_nmi */ if (!nested) nmi_enter(); /* * System reset can interrupt code where HSRRs are live and MSR[RI]=1. * The system reset interrupt itself may clobber HSRRs (e.g., to call * OPAL), so save them here and restore them before returning. * * Machine checks don't need to save HSRRs, as the real mode handler * is careful to avoid them, and the regular handler is not delivered * as an NMI. */ if (cpu_has_feature(CPU_FTR_HVMODE)) { hsrr0 = mfspr(SPRN_HSRR0); hsrr1 = mfspr(SPRN_HSRR1); saved_hsrrs = true; } hv_nmi_check_nonrecoverable(regs); __this_cpu_inc(irq_stat.sreset_irqs); /* See if any machine dependent calls */ if (ppc_md.system_reset_exception) { if (ppc_md.system_reset_exception(regs)) goto out; } if (debugger(regs)) goto out; kmsg_dump(KMSG_DUMP_OOPS); /* * A system reset is a request to dump, so we always send * it through the crashdump code (if fadump or kdump are * registered). */ crash_fadump(regs, "System Reset"); crash_kexec(regs); /* * We aren't the primary crash CPU. We need to send it * to a holding pattern to avoid it ending up in the panic * code. */ crash_kexec_secondary(regs); /* * No debugger or crash dump registered, print logs then * panic. */ die("System Reset", regs, SIGABRT); mdelay(2*MSEC_PER_SEC); /* Wait a little while for others to print */ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); nmi_panic(regs, "System Reset"); out: #ifdef CONFIG_PPC_BOOK3S_64 BUG_ON(get_paca()->in_nmi == 0); if (get_paca()->in_nmi > 1) die("Unrecoverable nested System Reset", regs, SIGABRT); #endif /* Must die if the interrupt is not recoverable */ if (!(regs->msr & MSR_RI)) die("Unrecoverable System Reset", regs, SIGABRT); if (saved_hsrrs) { mtspr(SPRN_HSRR0, hsrr0); mtspr(SPRN_HSRR1, hsrr1); } if (!nested) nmi_exit(); this_cpu_set_ftrace_enabled(ftrace_enabled); /* What should we do here? We could issue a shutdown or hard reset. */ } /* * I/O accesses can cause machine checks on powermacs. * Check if the NIP corresponds to the address of a sync * instruction for which there is an entry in the exception * table. * Note that the 601 only takes a machine check on TEA * (transfer error ack) signal assertion, and does not * set any of the top 16 bits of SRR1. * -- paulus. */ static inline int check_io_access(struct pt_regs *regs) { #ifdef CONFIG_PPC32 unsigned long msr = regs->msr; const struct exception_table_entry *entry; unsigned int *nip = (unsigned int *)regs->nip; if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000))) && (entry = search_exception_tables(regs->nip)) != NULL) { /* * Check that it's a sync instruction, or somewhere * in the twi; isync; nop sequence that inb/inw/inl uses. * As the address is in the exception table * we should be able to read the instr there. * For the debug message, we look at the preceding * load or store. */ if (*nip == PPC_INST_NOP) nip -= 2; else if (*nip == PPC_INST_ISYNC) --nip; if (*nip == PPC_INST_SYNC || (*nip >> 26) == OP_TRAP) { unsigned int rb; --nip; rb = (*nip >> 11) & 0x1f; printk(KERN_DEBUG "%s bad port %lx at %p\n", (*nip & 0x100)? "OUT to": "IN from", regs->gpr[rb] - _IO_BASE, nip); regs->msr |= MSR_RI; regs->nip = extable_fixup(entry); return 1; } } #endif /* CONFIG_PPC32 */ return 0; } #ifdef CONFIG_PPC_ADV_DEBUG_REGS /* On 4xx, the reason for the machine check or program exception is in the ESR. */ #define get_reason(regs) ((regs)->dsisr) #define REASON_FP ESR_FP #define REASON_ILLEGAL (ESR_PIL | ESR_PUO) #define REASON_PRIVILEGED ESR_PPR #define REASON_TRAP ESR_PTR #define REASON_PREFIXED 0 #define REASON_BOUNDARY 0 /* single-step stuff */ #define single_stepping(regs) (current->thread.debug.dbcr0 & DBCR0_IC) #define clear_single_step(regs) (current->thread.debug.dbcr0 &= ~DBCR0_IC) #define clear_br_trace(regs) do {} while(0) #else /* On non-4xx, the reason for the machine check or program exception is in the MSR. */ #define get_reason(regs) ((regs)->msr) #define REASON_TM SRR1_PROGTM #define REASON_FP SRR1_PROGFPE #define REASON_ILLEGAL SRR1_PROGILL #define REASON_PRIVILEGED SRR1_PROGPRIV #define REASON_TRAP SRR1_PROGTRAP #define REASON_PREFIXED SRR1_PREFIXED #define REASON_BOUNDARY SRR1_BOUNDARY #define single_stepping(regs) ((regs)->msr & MSR_SE) #define clear_single_step(regs) ((regs)->msr &= ~MSR_SE) #define clear_br_trace(regs) ((regs)->msr &= ~MSR_BE) #endif #define inst_length(reason) (((reason) & REASON_PREFIXED) ? 8 : 4) #if defined(CONFIG_E500) int machine_check_e500mc(struct pt_regs *regs) { unsigned long mcsr = mfspr(SPRN_MCSR); unsigned long pvr = mfspr(SPRN_PVR); unsigned long reason = mcsr; int recoverable = 1; if (reason & MCSR_LD) { recoverable = fsl_rio_mcheck_exception(regs); if (recoverable == 1) goto silent_out; } printk("Machine check in kernel mode.\n"); printk("Caused by (from MCSR=%lx): ", reason); if (reason & MCSR_MCP) pr_cont("Machine Check Signal\n"); if (reason & MCSR_ICPERR) { pr_cont("Instruction Cache Parity Error\n"); /* * This is recoverable by invalidating the i-cache. */ mtspr(SPRN_L1CSR1, mfspr(SPRN_L1CSR1) | L1CSR1_ICFI); while (mfspr(SPRN_L1CSR1) & L1CSR1_ICFI) ; /* * This will generally be accompanied by an instruction * fetch error report -- only treat MCSR_IF as fatal * if it wasn't due to an L1 parity error. */ reason &= ~MCSR_IF; } if (reason & MCSR_DCPERR_MC) { pr_cont("Data Cache Parity Error\n"); /* * In write shadow mode we auto-recover from the error, but it * may still get logged and cause a machine check. We should * only treat the non-write shadow case as non-recoverable. */ /* On e6500 core, L1 DCWS (Data cache write shadow mode) bit * is not implemented but L1 data cache always runs in write * shadow mode. Hence on data cache parity errors HW will * automatically invalidate the L1 Data Cache. */ if (PVR_VER(pvr) != PVR_VER_E6500) { if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS)) recoverable = 0; } } if (reason & MCSR_L2MMU_MHIT) { pr_cont("Hit on multiple TLB entries\n"); recoverable = 0; } if (reason & MCSR_NMI) pr_cont("Non-maskable interrupt\n"); if (reason & MCSR_IF) { pr_cont("Instruction Fetch Error Report\n"); recoverable = 0; } if (reason & MCSR_LD) { pr_cont("Load Error Report\n"); recoverable = 0; } if (reason & MCSR_ST) { pr_cont("Store Error Report\n"); recoverable = 0; } if (reason & MCSR_LDG) { pr_cont("Guarded Load Error Report\n"); recoverable = 0; } if (reason & MCSR_TLBSYNC) pr_cont("Simultaneous tlbsync operations\n"); if (reason & MCSR_BSL2_ERR) { pr_cont("Level 2 Cache Error\n"); recoverable = 0; } if (reason & MCSR_MAV) { u64 addr; addr = mfspr(SPRN_MCAR); addr |= (u64)mfspr(SPRN_MCARU) << 32; pr_cont("Machine Check %s Address: %#llx\n", reason & MCSR_MEA ? "Effective" : "Physical", addr); } silent_out: mtspr(SPRN_MCSR, mcsr); return mfspr(SPRN_MCSR) == 0 && recoverable; } int machine_check_e500(struct pt_regs *regs) { unsigned long reason = mfspr(SPRN_MCSR); if (reason & MCSR_BUS_RBERR) { if (fsl_rio_mcheck_exception(regs)) return 1; if (fsl_pci_mcheck_exception(regs)) return 1; } printk("Machine check in kernel mode.\n"); printk("Caused by (from MCSR=%lx): ", reason); if (reason & MCSR_MCP) pr_cont("Machine Check Signal\n"); if (reason & MCSR_ICPERR) pr_cont("Instruction Cache Parity Error\n"); if (reason & MCSR_DCP_PERR) pr_cont("Data Cache Push Parity Error\n"); if (reason & MCSR_DCPERR) pr_cont("Data Cache Parity Error\n"); if (reason & MCSR_BUS_IAERR) pr_cont("Bus - Instruction Address Error\n"); if (reason & MCSR_BUS_RAERR) pr_cont("Bus - Read Address Error\n"); if (reason & MCSR_BUS_WAERR) pr_cont("Bus - Write Address Error\n"); if (reason & MCSR_BUS_IBERR) pr_cont("Bus - Instruction Data Error\n"); if (reason & MCSR_BUS_RBERR) pr_cont("Bus - Read Data Bus Error\n"); if (reason & MCSR_BUS_WBERR) pr_cont("Bus - Write Data Bus Error\n"); if (reason & MCSR_BUS_IPERR) pr_cont("Bus - Instruction Parity Error\n"); if (reason & MCSR_BUS_RPERR) pr_cont("Bus - Read Parity Error\n"); return 0; } int machine_check_generic(struct pt_regs *regs) { return 0; } #elif defined(CONFIG_E200) int machine_check_e200(struct pt_regs *regs) { unsigned long reason = mfspr(SPRN_MCSR); printk("Machine check in kernel mode.\n"); printk("Caused by (from MCSR=%lx): ", reason); if (reason & MCSR_MCP) pr_cont("Machine Check Signal\n"); if (reason & MCSR_CP_PERR) pr_cont("Cache Push Parity Error\n"); if (reason & MCSR_CPERR) pr_cont("Cache Parity Error\n"); if (reason & MCSR_EXCP_ERR) pr_cont("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n"); if (reason & MCSR_BUS_IRERR) pr_cont("Bus - Read Bus Error on instruction fetch\n"); if (reason & MCSR_BUS_DRERR) pr_cont("Bus - Read Bus Error on data load\n"); if (reason & MCSR_BUS_WRERR) pr_cont("Bus - Write Bus Error on buffered store or cache line push\n"); return 0; } #elif defined(CONFIG_PPC32) int machine_check_generic(struct pt_regs *regs) { unsigned long reason = regs->msr; printk("Machine check in kernel mode.\n"); printk("Caused by (from SRR1=%lx): ", reason); switch (reason & 0x601F0000) { case 0x80000: pr_cont("Machine check signal\n"); break; case 0: /* for 601 */ case 0x40000: case 0x140000: /* 7450 MSS error and TEA */ pr_cont("Transfer error ack signal\n"); break; case 0x20000: pr_cont("Data parity error signal\n"); break; case 0x10000: pr_cont("Address parity error signal\n"); break; case 0x20000000: pr_cont("L1 Data Cache error\n"); break; case 0x40000000: pr_cont("L1 Instruction Cache error\n"); break; case 0x00100000: pr_cont("L2 data cache parity error\n"); break; default: pr_cont("Unknown values in msr\n"); } return 0; } #endif /* everything else */ void machine_check_exception(struct pt_regs *regs) { int recover = 0; bool nested; /* * BOOK3S_64 does not call this handler as a non-maskable interrupt * (it uses its own early real-mode handler to handle the MCE proper * and then raises irq_work to call this handler when interrupts are * enabled). Set nested = true for this case, which just makes it avoid * the nmi_enter/exit. */ if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) || in_nmi()) nested = true; else nested = false; if (!nested) nmi_enter(); __this_cpu_inc(irq_stat.mce_exceptions); add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); /* See if any machine dependent calls. In theory, we would want * to call the CPU first, and call the ppc_md. one if the CPU * one returns a positive number. However there is existing code * that assumes the board gets a first chance, so let's keep it * that way for now and fix things later. --BenH. */ if (ppc_md.machine_check_exception) recover = ppc_md.machine_check_exception(regs); else if (cur_cpu_spec->machine_check) recover = cur_cpu_spec->machine_check(regs); if (recover > 0) goto bail; if (debugger_fault_handler(regs)) goto bail; if (check_io_access(regs)) goto bail; if (!nested) nmi_exit(); die("Machine check", regs, SIGBUS); /* Must die if the interrupt is not recoverable */ if (!(regs->msr & MSR_RI)) die("Unrecoverable Machine check", regs, SIGBUS); return; bail: if (!nested) nmi_exit(); } void SMIException(struct pt_regs *regs) { die("System Management Interrupt", regs, SIGABRT); } #ifdef CONFIG_VSX static void p9_hmi_special_emu(struct pt_regs *regs) { unsigned int ra, rb, t, i, sel, instr, rc; const void __user *addr; u8 vbuf[16], *vdst; unsigned long ea, msr, msr_mask; bool swap; if (__get_user_inatomic(instr, (unsigned int __user *)regs->nip)) return; /* * lxvb16x opcode: 0x7c0006d8 * lxvd2x opcode: 0x7c000698 * lxvh8x opcode: 0x7c000658 * lxvw4x opcode: 0x7c000618 */ if ((instr & 0xfc00073e) != 0x7c000618) { pr_devel("HMI vec emu: not vector CI %i:%s[%d] nip=%016lx" " instr=%08x\n", smp_processor_id(), current->comm, current->pid, regs->nip, instr); return; } /* Grab vector registers into the task struct */ msr = regs->msr; /* Grab msr before we flush the bits */ flush_vsx_to_thread(current); enable_kernel_altivec(); /* * Is userspace running with a different endian (this is rare but * not impossible) */ swap = (msr & MSR_LE) != (MSR_KERNEL & MSR_LE); /* Decode the instruction */ ra = (instr >> 16) & 0x1f; rb = (instr >> 11) & 0x1f; t = (instr >> 21) & 0x1f; if (instr & 1) vdst = (u8 *)¤t->thread.vr_state.vr[t]; else vdst = (u8 *)¤t->thread.fp_state.fpr[t][0]; /* Grab the vector address */ ea = regs->gpr[rb] + (ra ? regs->gpr[ra] : 0); if (is_32bit_task()) ea &= 0xfffffffful; addr = (__force const void __user *)ea; /* Check it */ if (!access_ok(addr, 16)) { pr_devel("HMI vec emu: bad access %i:%s[%d] nip=%016lx" " instr=%08x addr=%016lx\n", smp_processor_id(), current->comm, current->pid, regs->nip, instr, (unsigned long)addr); return; } /* Read the vector */ rc = 0; if ((unsigned long)addr & 0xfUL) /* unaligned case */ rc = __copy_from_user_inatomic(vbuf, addr, 16); else __get_user_atomic_128_aligned(vbuf, addr, rc); if (rc) { pr_devel("HMI vec emu: page fault %i:%s[%d] nip=%016lx" " instr=%08x addr=%016lx\n", smp_processor_id(), current->comm, current->pid, regs->nip, instr, (unsigned long)addr); return; } pr_devel("HMI vec emu: emulated vector CI %i:%s[%d] nip=%016lx" " instr=%08x addr=%016lx\n", smp_processor_id(), current->comm, current->pid, regs->nip, instr, (unsigned long) addr); /* Grab instruction "selector" */ sel = (instr >> 6) & 3; /* * Check to make sure the facility is actually enabled. This * could happen if we get a false positive hit. * * lxvd2x/lxvw4x always check MSR VSX sel = 0,2 * lxvh8x/lxvb16x check MSR VSX or VEC depending on VSR used sel = 1,3 */ msr_mask = MSR_VSX; if ((sel & 1) && (instr & 1)) /* lxvh8x & lxvb16x + VSR >= 32 */ msr_mask = MSR_VEC; if (!(msr & msr_mask)) { pr_devel("HMI vec emu: MSR fac clear %i:%s[%d] nip=%016lx" " instr=%08x msr:%016lx\n", smp_processor_id(), current->comm, current->pid, regs->nip, instr, msr); return; } /* Do logging here before we modify sel based on endian */ switch (sel) { case 0: /* lxvw4x */ PPC_WARN_EMULATED(lxvw4x, regs); break; case 1: /* lxvh8x */ PPC_WARN_EMULATED(lxvh8x, regs); break; case 2: /* lxvd2x */ PPC_WARN_EMULATED(lxvd2x, regs); break; case 3: /* lxvb16x */ PPC_WARN_EMULATED(lxvb16x, regs); break; } #ifdef __LITTLE_ENDIAN__ /* * An LE kernel stores the vector in the task struct as an LE * byte array (effectively swapping both the components and * the content of the components). Those instructions expect * the components to remain in ascending address order, so we * swap them back. * * If we are running a BE user space, the expectation is that * of a simple memcpy, so forcing the emulation to look like * a lxvb16x should do the trick. */ if (swap) sel = 3; switch (sel) { case 0: /* lxvw4x */ for (i = 0; i < 4; i++) ((u32 *)vdst)[i] = ((u32 *)vbuf)[3-i]; break; case 1: /* lxvh8x */ for (i = 0; i < 8; i++) ((u16 *)vdst)[i] = ((u16 *)vbuf)[7-i]; break; case 2: /* lxvd2x */ for (i = 0; i < 2; i++) ((u64 *)vdst)[i] = ((u64 *)vbuf)[1-i]; break; case 3: /* lxvb16x */ for (i = 0; i < 16; i++) vdst[i] = vbuf[15-i]; break; } #else /* __LITTLE_ENDIAN__ */ /* On a big endian kernel, a BE userspace only needs a memcpy */ if (!swap) sel = 3; /* Otherwise, we need to swap the content of the components */ switch (sel) { case 0: /* lxvw4x */ for (i = 0; i < 4; i++) ((u32 *)vdst)[i] = cpu_to_le32(((u32 *)vbuf)[i]); break; case 1: /* lxvh8x */ for (i = 0; i < 8; i++) ((u16 *)vdst)[i] = cpu_to_le16(((u16 *)vbuf)[i]); break; case 2: /* lxvd2x */ for (i = 0; i < 2; i++) ((u64 *)vdst)[i] = cpu_to_le64(((u64 *)vbuf)[i]); break; case 3: /* lxvb16x */ memcpy(vdst, vbuf, 16); break; } #endif /* !__LITTLE_ENDIAN__ */ /* Go to next instruction */ regs->nip += 4; } #endif /* CONFIG_VSX */ void handle_hmi_exception(struct pt_regs *regs) { struct pt_regs *old_regs; old_regs = set_irq_regs(regs); irq_enter(); #ifdef CONFIG_VSX /* Real mode flagged P9 special emu is needed */ if (local_paca->hmi_p9_special_emu) { local_paca->hmi_p9_special_emu = 0; /* * We don't want to take page faults while doing the * emulation, we just replay the instruction if necessary. */ pagefault_disable(); p9_hmi_special_emu(regs); pagefault_enable(); } #endif /* CONFIG_VSX */ if (ppc_md.handle_hmi_exception) ppc_md.handle_hmi_exception(regs); irq_exit(); set_irq_regs(old_regs); } void unknown_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", regs->nip, regs->msr, regs->trap); _exception(SIGTRAP, regs, TRAP_UNK, 0); exception_exit(prev_state); } void instruction_breakpoint_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) goto bail; if (debugger_iabr_match(regs)) goto bail; _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip); bail: exception_exit(prev_state); } void RunModeException(struct pt_regs *regs) { _exception(SIGTRAP, regs, TRAP_UNK, 0); } void single_step_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); clear_single_step(regs); clear_br_trace(regs); if (kprobe_post_handler(regs)) return; if (notify_die(DIE_SSTEP, "single_step", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) goto bail; if (debugger_sstep(regs)) goto bail; _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip); bail: exception_exit(prev_state); } NOKPROBE_SYMBOL(single_step_exception); /* * After we have successfully emulated an instruction, we have to * check if the instruction was being single-stepped, and if so, * pretend we got a single-step exception. This was pointed out * by Kumar Gala. -- paulus */ static void emulate_single_step(struct pt_regs *regs) { if (single_stepping(regs)) single_step_exception(regs); } static inline int __parse_fpscr(unsigned long fpscr) { int ret = FPE_FLTUNK; /* Invalid operation */ if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX)) ret = FPE_FLTINV; /* Overflow */ else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX)) ret = FPE_FLTOVF; /* Underflow */ else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX)) ret = FPE_FLTUND; /* Divide by zero */ else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX)) ret = FPE_FLTDIV; /* Inexact result */ else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX)) ret = FPE_FLTRES; return ret; } static void parse_fpe(struct pt_regs *regs) { int code = 0; flush_fp_to_thread(current); code = __parse_fpscr(current->thread.fp_state.fpscr); _exception(SIGFPE, regs, code, regs->nip); } /* * Illegal instruction emulation support. Originally written to * provide the PVR to user applications using the mfspr rd, PVR. * Return non-zero if we can't emulate, or -EFAULT if the associated * memory access caused an access fault. Return zero on success. * * There are a couple of ways to do this, either "decode" the instruction * or directly match lots of bits. In this case, matching lots of * bits is faster and easier. * */ static int emulate_string_inst(struct pt_regs *regs, u32 instword) { u8 rT = (instword >> 21) & 0x1f; u8 rA = (instword >> 16) & 0x1f; u8 NB_RB = (instword >> 11) & 0x1f; u32 num_bytes; unsigned long EA; int pos = 0; /* Early out if we are an invalid form of lswx */ if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX) if ((rT == rA) || (rT == NB_RB)) return -EINVAL; EA = (rA == 0) ? 0 : regs->gpr[rA]; switch (instword & PPC_INST_STRING_MASK) { case PPC_INST_LSWX: case PPC_INST_STSWX: EA += NB_RB; num_bytes = regs->xer & 0x7f; break; case PPC_INST_LSWI: case PPC_INST_STSWI: num_bytes = (NB_RB == 0) ? 32 : NB_RB; break; default: return -EINVAL; } while (num_bytes != 0) { u8 val; u32 shift = 8 * (3 - (pos & 0x3)); /* if process is 32-bit, clear upper 32 bits of EA */ if ((regs->msr & MSR_64BIT) == 0) EA &= 0xFFFFFFFF; switch ((instword & PPC_INST_STRING_MASK)) { case PPC_INST_LSWX: case PPC_INST_LSWI: if (get_user(val, (u8 __user *)EA)) return -EFAULT; /* first time updating this reg, * zero it out */ if (pos == 0) regs->gpr[rT] = 0; regs->gpr[rT] |= val << shift; break; case PPC_INST_STSWI: case PPC_INST_STSWX: val = regs->gpr[rT] >> shift; if (put_user(val, (u8 __user *)EA)) return -EFAULT; break; } /* move EA to next address */ EA += 1; num_bytes--; /* manage our position within the register */ if (++pos == 4) { pos = 0; if (++rT == 32) rT = 0; } } return 0; } static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword) { u32 ra,rs; unsigned long tmp; ra = (instword >> 16) & 0x1f; rs = (instword >> 21) & 0x1f; tmp = regs->gpr[rs]; tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL); tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL); tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL; regs->gpr[ra] = tmp; return 0; } static int emulate_isel(struct pt_regs *regs, u32 instword) { u8 rT = (instword >> 21) & 0x1f; u8 rA = (instword >> 16) & 0x1f; u8 rB = (instword >> 11) & 0x1f; u8 BC = (instword >> 6) & 0x1f; u8 bit; unsigned long tmp; tmp = (rA == 0) ? 0 : regs->gpr[rA]; bit = (regs->ccr >> (31 - BC)) & 0x1; regs->gpr[rT] = bit ? tmp : regs->gpr[rB]; return 0; } #ifdef CONFIG_PPC_TRANSACTIONAL_MEM static inline bool tm_abort_check(struct pt_regs *regs, int cause) { /* If we're emulating a load/store in an active transaction, we cannot * emulate it as the kernel operates in transaction suspended context. * We need to abort the transaction. This creates a persistent TM * abort so tell the user what caused it with a new code. */ if (MSR_TM_TRANSACTIONAL(regs->msr)) { tm_enable(); tm_abort(cause); return true; } return false; } #else static inline bool tm_abort_check(struct pt_regs *regs, int reason) { return false; } #endif static int emulate_instruction(struct pt_regs *regs) { u32 instword; u32 rd; if (!user_mode(regs)) return -EINVAL; CHECK_FULL_REGS(regs); if (get_user(instword, (u32 __user *)(regs->nip))) return -EFAULT; /* Emulate the mfspr rD, PVR. */ if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) { PPC_WARN_EMULATED(mfpvr, regs); rd = (instword >> 21) & 0x1f; regs->gpr[rd] = mfspr(SPRN_PVR); return 0; } /* Emulating the dcba insn is just a no-op. */ if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) { PPC_WARN_EMULATED(dcba, regs); return 0; } /* Emulate the mcrxr insn. */ if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) { int shift = (instword >> 21) & 0x1c; unsigned long msk = 0xf0000000UL >> shift; PPC_WARN_EMULATED(mcrxr, regs); regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk); regs->xer &= ~0xf0000000UL; return 0; } /* Emulate load/store string insn. */ if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) { if (tm_abort_check(regs, TM_CAUSE_EMULATE | TM_CAUSE_PERSISTENT)) return -EINVAL; PPC_WARN_EMULATED(string, regs); return emulate_string_inst(regs, instword); } /* Emulate the popcntb (Population Count Bytes) instruction. */ if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) { PPC_WARN_EMULATED(popcntb, regs); return emulate_popcntb_inst(regs, instword); } /* Emulate isel (Integer Select) instruction */ if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) { PPC_WARN_EMULATED(isel, regs); return emulate_isel(regs, instword); } /* Emulate sync instruction variants */ if ((instword & PPC_INST_SYNC_MASK) == PPC_INST_SYNC) { PPC_WARN_EMULATED(sync, regs); asm volatile("sync"); return 0; } #ifdef CONFIG_PPC64 /* Emulate the mfspr rD, DSCR. */ if ((((instword & PPC_INST_MFSPR_DSCR_USER_MASK) == PPC_INST_MFSPR_DSCR_USER) || ((instword & PPC_INST_MFSPR_DSCR_MASK) == PPC_INST_MFSPR_DSCR)) && cpu_has_feature(CPU_FTR_DSCR)) { PPC_WARN_EMULATED(mfdscr, regs); rd = (instword >> 21) & 0x1f; regs->gpr[rd] = mfspr(SPRN_DSCR); return 0; } /* Emulate the mtspr DSCR, rD. */ if ((((instword & PPC_INST_MTSPR_DSCR_USER_MASK) == PPC_INST_MTSPR_DSCR_USER) || ((instword & PPC_INST_MTSPR_DSCR_MASK) == PPC_INST_MTSPR_DSCR)) && cpu_has_feature(CPU_FTR_DSCR)) { PPC_WARN_EMULATED(mtdscr, regs); rd = (instword >> 21) & 0x1f; current->thread.dscr = regs->gpr[rd]; current->thread.dscr_inherit = 1; mtspr(SPRN_DSCR, current->thread.dscr); return 0; } #endif return -EINVAL; } int is_valid_bugaddr(unsigned long addr) { return is_kernel_addr(addr); } #ifdef CONFIG_MATH_EMULATION static int emulate_math(struct pt_regs *regs) { int ret; extern int do_mathemu(struct pt_regs *regs); ret = do_mathemu(regs); if (ret >= 0) PPC_WARN_EMULATED(math, regs); switch (ret) { case 0: emulate_single_step(regs); return 0; case 1: { int code = 0; code = __parse_fpscr(current->thread.fp_state.fpscr); _exception(SIGFPE, regs, code, regs->nip); return 0; } case -EFAULT: _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); return 0; } return -1; } #else static inline int emulate_math(struct pt_regs *regs) { return -1; } #endif void program_check_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); unsigned int reason = get_reason(regs); /* We can now get here via a FP Unavailable exception if the core * has no FPU, in that case the reason flags will be 0 */ if (reason & REASON_FP) { /* IEEE FP exception */ parse_fpe(regs); goto bail; } if (reason & REASON_TRAP) { unsigned long bugaddr; /* Debugger is first in line to stop recursive faults in * rcu_lock, notify_die, or atomic_notifier_call_chain */ if (debugger_bpt(regs)) goto bail; if (kprobe_handler(regs)) goto bail; /* trap exception */ if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) goto bail; bugaddr = regs->nip; /* * Fixup bugaddr for BUG_ON() in real mode */ if (!is_kernel_addr(bugaddr) && !(regs->msr & MSR_IR)) bugaddr += PAGE_OFFSET; if (!(regs->msr & MSR_PR) && /* not user-mode */ report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) { regs->nip += 4; goto bail; } _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip); goto bail; } #ifdef CONFIG_PPC_TRANSACTIONAL_MEM if (reason & REASON_TM) { /* This is a TM "Bad Thing Exception" program check. * This occurs when: * - An rfid/hrfid/mtmsrd attempts to cause an illegal * transition in TM states. * - A trechkpt is attempted when transactional. * - A treclaim is attempted when non transactional. * - A tend is illegally attempted. * - writing a TM SPR when transactional. * * If usermode caused this, it's done something illegal and * gets a SIGILL slap on the wrist. We call it an illegal * operand to distinguish from the instruction just being bad * (e.g. executing a 'tend' on a CPU without TM!); it's an * illegal /placement/ of a valid instruction. */ if (user_mode(regs)) { _exception(SIGILL, regs, ILL_ILLOPN, regs->nip); goto bail; } else { printk(KERN_EMERG "Unexpected TM Bad Thing exception " "at %lx (msr 0x%lx) tm_scratch=%llx\n", regs->nip, regs->msr, get_paca()->tm_scratch); die("Unrecoverable exception", regs, SIGABRT); } } #endif /* * If we took the program check in the kernel skip down to sending a * SIGILL. The subsequent cases all relate to emulating instructions * which we should only do for userspace. We also do not want to enable * interrupts for kernel faults because that might lead to further * faults, and loose the context of the original exception. */ if (!user_mode(regs)) goto sigill; /* We restore the interrupt state now */ if (!arch_irq_disabled_regs(regs)) local_irq_enable(); /* (reason & REASON_ILLEGAL) would be the obvious thing here, * but there seems to be a hardware bug on the 405GP (RevD) * that means ESR is sometimes set incorrectly - either to * ESR_DST (!?) or 0. In the process of chasing this with the * hardware people - not sure if it can happen on any illegal * instruction or only on FP instructions, whether there is a * pattern to occurrences etc. -dgibson 31/Mar/2003 */ if (!emulate_math(regs)) goto bail; /* Try to emulate it if we should. */ if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) { switch (emulate_instruction(regs)) { case 0: regs->nip += 4; emulate_single_step(regs); goto bail; case -EFAULT: _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); goto bail; } } sigill: if (reason & REASON_PRIVILEGED) _exception(SIGILL, regs, ILL_PRVOPC, regs->nip); else _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); bail: exception_exit(prev_state); } NOKPROBE_SYMBOL(program_check_exception); /* * This occurs when running in hypervisor mode on POWER6 or later * and an illegal instruction is encountered. */ void emulation_assist_interrupt(struct pt_regs *regs) { regs->msr |= REASON_ILLEGAL; program_check_exception(regs); } NOKPROBE_SYMBOL(emulation_assist_interrupt); void alignment_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); int sig, code, fixed = 0; unsigned long reason; /* We restore the interrupt state now */ if (!arch_irq_disabled_regs(regs)) local_irq_enable(); reason = get_reason(regs); if (reason & REASON_BOUNDARY) { sig = SIGBUS; code = BUS_ADRALN; goto bad; } if (tm_abort_check(regs, TM_CAUSE_ALIGNMENT | TM_CAUSE_PERSISTENT)) goto bail; /* we don't implement logging of alignment exceptions */ if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS)) fixed = fix_alignment(regs); if (fixed == 1) { /* skip over emulated instruction */ regs->nip += inst_length(reason); emulate_single_step(regs); goto bail; } /* Operand address was bad */ if (fixed == -EFAULT) { sig = SIGSEGV; code = SEGV_ACCERR; } else { sig = SIGBUS; code = BUS_ADRALN; } bad: if (user_mode(regs)) _exception(sig, regs, code, regs->dar); else bad_page_fault(regs, regs->dar, sig); bail: exception_exit(prev_state); } void StackOverflow(struct pt_regs *regs) { pr_crit("Kernel stack overflow in process %s[%d], r1=%lx\n", current->comm, task_pid_nr(current), regs->gpr[1]); debugger(regs); show_regs(regs); panic("kernel stack overflow"); } void stack_overflow_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); die("Kernel stack overflow", regs, SIGSEGV); exception_exit(prev_state); } void kernel_fp_unavailable_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); printk(KERN_EMERG "Unrecoverable FP Unavailable Exception " "%lx at %lx\n", regs->trap, regs->nip); die("Unrecoverable FP Unavailable Exception", regs, SIGABRT); exception_exit(prev_state); } void altivec_unavailable_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); if (user_mode(regs)) { /* A user program has executed an altivec instruction, but this kernel doesn't support altivec. */ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); goto bail; } printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception " "%lx at %lx\n", regs->trap, regs->nip); die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT); bail: exception_exit(prev_state); } void vsx_unavailable_exception(struct pt_regs *regs) { if (user_mode(regs)) { /* A user program has executed an vsx instruction, but this kernel doesn't support vsx. */ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); return; } printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception " "%lx at %lx\n", regs->trap, regs->nip); die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT); } #ifdef CONFIG_PPC64 static void tm_unavailable(struct pt_regs *regs) { #ifdef CONFIG_PPC_TRANSACTIONAL_MEM if (user_mode(regs)) { current->thread.load_tm++; regs->msr |= MSR_TM; tm_enable(); tm_restore_sprs(¤t->thread); return; } #endif pr_emerg("Unrecoverable TM Unavailable Exception " "%lx at %lx\n", regs->trap, regs->nip); die("Unrecoverable TM Unavailable Exception", regs, SIGABRT); } void facility_unavailable_exception(struct pt_regs *regs) { static char *facility_strings[] = { [FSCR_FP_LG] = "FPU", [FSCR_VECVSX_LG] = "VMX/VSX", [FSCR_DSCR_LG] = "DSCR", [FSCR_PM_LG] = "PMU SPRs", [FSCR_BHRB_LG] = "BHRB", [FSCR_TM_LG] = "TM", [FSCR_EBB_LG] = "EBB", [FSCR_TAR_LG] = "TAR", [FSCR_MSGP_LG] = "MSGP", [FSCR_SCV_LG] = "SCV", [FSCR_PREFIX_LG] = "PREFIX", }; char *facility = "unknown"; u64 value; u32 instword, rd; u8 status; bool hv; hv = (TRAP(regs) == 0xf80); if (hv) value = mfspr(SPRN_HFSCR); else value = mfspr(SPRN_FSCR); status = value >> 56; if ((hv || status >= 2) && (status < ARRAY_SIZE(facility_strings)) && facility_strings[status]) facility = facility_strings[status]; /* We should not have taken this interrupt in kernel */ if (!user_mode(regs)) { pr_emerg("Facility '%s' unavailable (%d) exception in kernel mode at %lx\n", facility, status, regs->nip); die("Unexpected facility unavailable exception", regs, SIGABRT); } /* We restore the interrupt state now */ if (!arch_irq_disabled_regs(regs)) local_irq_enable(); if (status == FSCR_DSCR_LG) { /* * User is accessing the DSCR register using the problem * state only SPR number (0x03) either through a mfspr or * a mtspr instruction. If it is a write attempt through * a mtspr, then we set the inherit bit. This also allows * the user to write or read the register directly in the * future by setting via the FSCR DSCR bit. But in case it * is a read DSCR attempt through a mfspr instruction, we * just emulate the instruction instead. This code path will * always emulate all the mfspr instructions till the user * has attempted at least one mtspr instruction. This way it * preserves the same behaviour when the user is accessing * the DSCR through privilege level only SPR number (0x11) * which is emulated through illegal instruction exception. * We always leave HFSCR DSCR set. */ if (get_user(instword, (u32 __user *)(regs->nip))) { pr_err("Failed to fetch the user instruction\n"); return; } /* Write into DSCR (mtspr 0x03, RS) */ if ((instword & PPC_INST_MTSPR_DSCR_USER_MASK) == PPC_INST_MTSPR_DSCR_USER) { rd = (instword >> 21) & 0x1f; current->thread.dscr = regs->gpr[rd]; current->thread.dscr_inherit = 1; current->thread.fscr |= FSCR_DSCR; mtspr(SPRN_FSCR, current->thread.fscr); } /* Read from DSCR (mfspr RT, 0x03) */ if ((instword & PPC_INST_MFSPR_DSCR_USER_MASK) == PPC_INST_MFSPR_DSCR_USER) { if (emulate_instruction(regs)) { pr_err("DSCR based mfspr emulation failed\n"); return; } regs->nip += 4; emulate_single_step(regs); } return; } if (status == FSCR_TM_LG) { /* * If we're here then the hardware is TM aware because it * generated an exception with FSRM_TM set. * * If cpu_has_feature(CPU_FTR_TM) is false, then either firmware * told us not to do TM, or the kernel is not built with TM * support. * * If both of those things are true, then userspace can spam the * console by triggering the printk() below just by continually * doing tbegin (or any TM instruction). So in that case just * send the process a SIGILL immediately. */ if (!cpu_has_feature(CPU_FTR_TM)) goto out; tm_unavailable(regs); return; } pr_err_ratelimited("%sFacility '%s' unavailable (%d), exception at 0x%lx, MSR=%lx\n", hv ? "Hypervisor " : "", facility, status, regs->nip, regs->msr); out: _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); } #endif #ifdef CONFIG_PPC_TRANSACTIONAL_MEM void fp_unavailable_tm(struct pt_regs *regs) { /* Note: This does not handle any kind of FP laziness. */ TM_DEBUG("FP Unavailable trap whilst transactional at 0x%lx, MSR=%lx\n", regs->nip, regs->msr); /* We can only have got here if the task started using FP after * beginning the transaction. So, the transactional regs are just a * copy of the checkpointed ones. But, we still need to recheckpoint * as we're enabling FP for the process; it will return, abort the * transaction, and probably retry but now with FP enabled. So the * checkpointed FP registers need to be loaded. */ tm_reclaim_current(TM_CAUSE_FAC_UNAV); /* * Reclaim initially saved out bogus (lazy) FPRs to ckfp_state, and * then it was overwrite by the thr->fp_state by tm_reclaim_thread(). * * At this point, ck{fp,vr}_state contains the exact values we want to * recheckpoint. */ /* Enable FP for the task: */ current->thread.load_fp = 1; /* * Recheckpoint all the checkpointed ckpt, ck{fp, vr}_state registers. */ tm_recheckpoint(¤t->thread); } void altivec_unavailable_tm(struct pt_regs *regs) { /* See the comments in fp_unavailable_tm(). This function operates * the same way. */ TM_DEBUG("Vector Unavailable trap whilst transactional at 0x%lx," "MSR=%lx\n", regs->nip, regs->msr); tm_reclaim_current(TM_CAUSE_FAC_UNAV); current->thread.load_vec = 1; tm_recheckpoint(¤t->thread); current->thread.used_vr = 1; } void vsx_unavailable_tm(struct pt_regs *regs) { /* See the comments in fp_unavailable_tm(). This works similarly, * though we're loading both FP and VEC registers in here. * * If FP isn't in use, load FP regs. If VEC isn't in use, load VEC * regs. Either way, set MSR_VSX. */ TM_DEBUG("VSX Unavailable trap whilst transactional at 0x%lx," "MSR=%lx\n", regs->nip, regs->msr); current->thread.used_vsr = 1; /* This reclaims FP and/or VR regs if they're already enabled */ tm_reclaim_current(TM_CAUSE_FAC_UNAV); current->thread.load_vec = 1; current->thread.load_fp = 1; tm_recheckpoint(¤t->thread); } #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ void performance_monitor_exception(struct pt_regs *regs) { __this_cpu_inc(irq_stat.pmu_irqs); perf_irq(regs); } #ifdef CONFIG_PPC_ADV_DEBUG_REGS static void handle_debug(struct pt_regs *regs, unsigned long debug_status) { int changed = 0; /* * Determine the cause of the debug event, clear the * event flags and send a trap to the handler. Torez */ if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) { dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W); #ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE current->thread.debug.dbcr2 &= ~DBCR2_DAC12MODE; #endif do_send_trap(regs, mfspr(SPRN_DAC1), debug_status, 5); changed |= 0x01; } else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) { dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W); do_send_trap(regs, mfspr(SPRN_DAC2), debug_status, 6); changed |= 0x01; } else if (debug_status & DBSR_IAC1) { current->thread.debug.dbcr0 &= ~DBCR0_IAC1; dbcr_iac_range(current) &= ~DBCR_IAC12MODE; do_send_trap(regs, mfspr(SPRN_IAC1), debug_status, 1); changed |= 0x01; } else if (debug_status & DBSR_IAC2) { current->thread.debug.dbcr0 &= ~DBCR0_IAC2; do_send_trap(regs, mfspr(SPRN_IAC2), debug_status, 2); changed |= 0x01; } else if (debug_status & DBSR_IAC3) { current->thread.debug.dbcr0 &= ~DBCR0_IAC3; dbcr_iac_range(current) &= ~DBCR_IAC34MODE; do_send_trap(regs, mfspr(SPRN_IAC3), debug_status, 3); changed |= 0x01; } else if (debug_status & DBSR_IAC4) { current->thread.debug.dbcr0 &= ~DBCR0_IAC4; do_send_trap(regs, mfspr(SPRN_IAC4), debug_status, 4); changed |= 0x01; } /* * At the point this routine was called, the MSR(DE) was turned off. * Check all other debug flags and see if that bit needs to be turned * back on or not. */ if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0, current->thread.debug.dbcr1)) regs->msr |= MSR_DE; else /* Make sure the IDM flag is off */ current->thread.debug.dbcr0 &= ~DBCR0_IDM; if (changed & 0x01) mtspr(SPRN_DBCR0, current->thread.debug.dbcr0); } void DebugException(struct pt_regs *regs, unsigned long debug_status) { current->thread.debug.dbsr = debug_status; /* Hack alert: On BookE, Branch Taken stops on the branch itself, while * on server, it stops on the target of the branch. In order to simulate * the server behaviour, we thus restart right away with a single step * instead of stopping here when hitting a BT */ if (debug_status & DBSR_BT) { regs->msr &= ~MSR_DE; /* Disable BT */ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT); /* Clear the BT event */ mtspr(SPRN_DBSR, DBSR_BT); /* Do the single step trick only when coming from userspace */ if (user_mode(regs)) { current->thread.debug.dbcr0 &= ~DBCR0_BT; current->thread.debug.dbcr0 |= DBCR0_IDM | DBCR0_IC; regs->msr |= MSR_DE; return; } if (kprobe_post_handler(regs)) return; if (notify_die(DIE_SSTEP, "block_step", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) { return; } if (debugger_sstep(regs)) return; } else if (debug_status & DBSR_IC) { /* Instruction complete */ regs->msr &= ~MSR_DE; /* Disable instruction completion */ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC); /* Clear the instruction completion event */ mtspr(SPRN_DBSR, DBSR_IC); if (kprobe_post_handler(regs)) return; if (notify_die(DIE_SSTEP, "single_step", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) { return; } if (debugger_sstep(regs)) return; if (user_mode(regs)) { current->thread.debug.dbcr0 &= ~DBCR0_IC; if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0, current->thread.debug.dbcr1)) regs->msr |= MSR_DE; else /* Make sure the IDM bit is off */ current->thread.debug.dbcr0 &= ~DBCR0_IDM; } _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip); } else handle_debug(regs, debug_status); } NOKPROBE_SYMBOL(DebugException); #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ #if !defined(CONFIG_TAU_INT) void TAUException(struct pt_regs *regs) { printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx %s\n", regs->nip, regs->msr, regs->trap, print_tainted()); } #endif /* CONFIG_INT_TAU */ #ifdef CONFIG_ALTIVEC void altivec_assist_exception(struct pt_regs *regs) { int err; if (!user_mode(regs)) { printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode" " at %lx\n", regs->nip); die("Kernel VMX/Altivec assist exception", regs, SIGILL); } flush_altivec_to_thread(current); PPC_WARN_EMULATED(altivec, regs); err = emulate_altivec(regs); if (err == 0) { regs->nip += 4; /* skip emulated instruction */ emulate_single_step(regs); return; } if (err == -EFAULT) { /* got an error reading the instruction */ _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); } else { /* didn't recognize the instruction */ /* XXX quick hack for now: set the non-Java bit in the VSCR */ printk_ratelimited(KERN_ERR "Unrecognized altivec instruction " "in %s at %lx\n", current->comm, regs->nip); current->thread.vr_state.vscr.u[3] |= 0x10000; } } #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_FSL_BOOKE void CacheLockingException(struct pt_regs *regs, unsigned long address, unsigned long error_code) { /* We treat cache locking instructions from the user * as priv ops, in the future we could try to do * something smarter */ if (error_code & (ESR_DLK|ESR_ILK)) _exception(SIGILL, regs, ILL_PRVOPC, regs->nip); return; } #endif /* CONFIG_FSL_BOOKE */ #ifdef CONFIG_SPE void SPEFloatingPointException(struct pt_regs *regs) { extern int do_spe_mathemu(struct pt_regs *regs); unsigned long spefscr; int fpexc_mode; int code = FPE_FLTUNK; int err; /* We restore the interrupt state now */ if (!arch_irq_disabled_regs(regs)) local_irq_enable(); flush_spe_to_thread(current); spefscr = current->thread.spefscr; fpexc_mode = current->thread.fpexc_mode; if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) { code = FPE_FLTOVF; } else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) { code = FPE_FLTUND; } else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV)) code = FPE_FLTDIV; else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) { code = FPE_FLTINV; } else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES)) code = FPE_FLTRES; err = do_spe_mathemu(regs); if (err == 0) { regs->nip += 4; /* skip emulated instruction */ emulate_single_step(regs); return; } if (err == -EFAULT) { /* got an error reading the instruction */ _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); } else if (err == -EINVAL) { /* didn't recognize the instruction */ printk(KERN_ERR "unrecognized spe instruction " "in %s at %lx\n", current->comm, regs->nip); } else { _exception(SIGFPE, regs, code, regs->nip); } return; } void SPEFloatingPointRoundException(struct pt_regs *regs) { extern int speround_handler(struct pt_regs *regs); int err; /* We restore the interrupt state now */ if (!arch_irq_disabled_regs(regs)) local_irq_enable(); preempt_disable(); if (regs->msr & MSR_SPE) giveup_spe(current); preempt_enable(); regs->nip -= 4; err = speround_handler(regs); if (err == 0) { regs->nip += 4; /* skip emulated instruction */ emulate_single_step(regs); return; } if (err == -EFAULT) { /* got an error reading the instruction */ _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); } else if (err == -EINVAL) { /* didn't recognize the instruction */ printk(KERN_ERR "unrecognized spe instruction " "in %s at %lx\n", current->comm, regs->nip); } else { _exception(SIGFPE, regs, FPE_FLTUNK, regs->nip); return; } } #endif /* * We enter here if we get an unrecoverable exception, that is, one * that happened at a point where the RI (recoverable interrupt) bit * in the MSR is 0. This indicates that SRR0/1 are live, and that * we therefore lost state by taking this exception. */ void unrecoverable_exception(struct pt_regs *regs) { pr_emerg("Unrecoverable exception %lx at %lx (msr=%lx)\n", regs->trap, regs->nip, regs->msr); die("Unrecoverable exception", regs, SIGABRT); } NOKPROBE_SYMBOL(unrecoverable_exception); #if defined(CONFIG_BOOKE_WDT) || defined(CONFIG_40x) /* * Default handler for a Watchdog exception, * spins until a reboot occurs */ void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs) { /* Generic WatchdogHandler, implement your own */ mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE)); return; } void WatchdogException(struct pt_regs *regs) { printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n"); WatchdogHandler(regs); } #endif /* * We enter here if we discover during exception entry that we are * running in supervisor mode with a userspace value in the stack pointer. */ void kernel_bad_stack(struct pt_regs *regs) { printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n", regs->gpr[1], regs->nip); die("Bad kernel stack pointer", regs, SIGABRT); } NOKPROBE_SYMBOL(kernel_bad_stack); void __init trap_init(void) { } #ifdef CONFIG_PPC_EMULATED_STATS #define WARN_EMULATED_SETUP(type) .type = { .name = #type } struct ppc_emulated ppc_emulated = { #ifdef CONFIG_ALTIVEC WARN_EMULATED_SETUP(altivec), #endif WARN_EMULATED_SETUP(dcba), WARN_EMULATED_SETUP(dcbz), WARN_EMULATED_SETUP(fp_pair), WARN_EMULATED_SETUP(isel), WARN_EMULATED_SETUP(mcrxr), WARN_EMULATED_SETUP(mfpvr), WARN_EMULATED_SETUP(multiple), WARN_EMULATED_SETUP(popcntb), WARN_EMULATED_SETUP(spe), WARN_EMULATED_SETUP(string), WARN_EMULATED_SETUP(sync), WARN_EMULATED_SETUP(unaligned), #ifdef CONFIG_MATH_EMULATION WARN_EMULATED_SETUP(math), #endif #ifdef CONFIG_VSX WARN_EMULATED_SETUP(vsx), #endif #ifdef CONFIG_PPC64 WARN_EMULATED_SETUP(mfdscr), WARN_EMULATED_SETUP(mtdscr), WARN_EMULATED_SETUP(lq_stq), WARN_EMULATED_SETUP(lxvw4x), WARN_EMULATED_SETUP(lxvh8x), WARN_EMULATED_SETUP(lxvd2x), WARN_EMULATED_SETUP(lxvb16x), #endif }; u32 ppc_warn_emulated; void ppc_warn_emulated_print(const char *type) { pr_warn_ratelimited("%s used emulated %s instruction\n", current->comm, type); } static int __init ppc_warn_emulated_init(void) { struct dentry *dir; unsigned int i; struct ppc_emulated_entry *entries = (void *)&ppc_emulated; dir = debugfs_create_dir("emulated_instructions", powerpc_debugfs_root); debugfs_create_u32("do_warn", 0644, dir, &ppc_warn_emulated); for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) debugfs_create_u32(entries[i].name, 0644, dir, (u32 *)&entries[i].val.counter); return 0; } device_initcall(ppc_warn_emulated_init); #endif /* CONFIG_PPC_EMULATED_STATS */