| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Machine check handler. |
| * |
| * K8 parts Copyright 2002,2003 Andi Kleen, SuSE Labs. |
| * Rest from unknown author(s). |
| * 2004 Andi Kleen. Rewrote most of it. |
| * Copyright 2008 Intel Corporation |
| * Author: Andi Kleen |
| */ |
| |
| #include <linux/thread_info.h> |
| #include <linux/capability.h> |
| #include <linux/miscdevice.h> |
| #include <linux/ratelimit.h> |
| #include <linux/rcupdate.h> |
| #include <linux/kobject.h> |
| #include <linux/uaccess.h> |
| #include <linux/kdebug.h> |
| #include <linux/kernel.h> |
| #include <linux/percpu.h> |
| #include <linux/string.h> |
| #include <linux/device.h> |
| #include <linux/syscore_ops.h> |
| #include <linux/delay.h> |
| #include <linux/ctype.h> |
| #include <linux/sched.h> |
| #include <linux/sysfs.h> |
| #include <linux/types.h> |
| #include <linux/slab.h> |
| #include <linux/init.h> |
| #include <linux/kmod.h> |
| #include <linux/poll.h> |
| #include <linux/nmi.h> |
| #include <linux/cpu.h> |
| #include <linux/ras.h> |
| #include <linux/smp.h> |
| #include <linux/fs.h> |
| #include <linux/mm.h> |
| #include <linux/debugfs.h> |
| #include <linux/irq_work.h> |
| #include <linux/export.h> |
| #include <linux/set_memory.h> |
| #include <linux/sync_core.h> |
| #include <linux/task_work.h> |
| #include <linux/hardirq.h> |
| |
| #include <asm/intel-family.h> |
| #include <asm/processor.h> |
| #include <asm/traps.h> |
| #include <asm/tlbflush.h> |
| #include <asm/mce.h> |
| #include <asm/msr.h> |
| #include <asm/reboot.h> |
| |
| #include "internal.h" |
| |
| /* sysfs synchronization */ |
| static DEFINE_MUTEX(mce_sysfs_mutex); |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/mce.h> |
| |
| #define SPINUNIT 100 /* 100ns */ |
| |
| DEFINE_PER_CPU(unsigned, mce_exception_count); |
| |
| DEFINE_PER_CPU_READ_MOSTLY(unsigned int, mce_num_banks); |
| |
| DEFINE_PER_CPU_READ_MOSTLY(struct mce_bank[MAX_NR_BANKS], mce_banks_array); |
| |
| #define ATTR_LEN 16 |
| /* One object for each MCE bank, shared by all CPUs */ |
| struct mce_bank_dev { |
| struct device_attribute attr; /* device attribute */ |
| char attrname[ATTR_LEN]; /* attribute name */ |
| u8 bank; /* bank number */ |
| }; |
| static struct mce_bank_dev mce_bank_devs[MAX_NR_BANKS]; |
| |
| struct mce_vendor_flags mce_flags __read_mostly; |
| |
| struct mca_config mca_cfg __read_mostly = { |
| .bootlog = -1, |
| .monarch_timeout = -1 |
| }; |
| |
| static DEFINE_PER_CPU(struct mce, mces_seen); |
| static unsigned long mce_need_notify; |
| |
| /* |
| * MCA banks polled by the period polling timer for corrected events. |
| * With Intel CMCI, this only has MCA banks which do not support CMCI (if any). |
| */ |
| DEFINE_PER_CPU(mce_banks_t, mce_poll_banks) = { |
| [0 ... BITS_TO_LONGS(MAX_NR_BANKS)-1] = ~0UL |
| }; |
| |
| /* |
| * MCA banks controlled through firmware first for corrected errors. |
| * This is a global list of banks for which we won't enable CMCI and we |
| * won't poll. Firmware controls these banks and is responsible for |
| * reporting corrected errors through GHES. Uncorrected/recoverable |
| * errors are still notified through a machine check. |
| */ |
| mce_banks_t mce_banks_ce_disabled; |
| |
| static struct work_struct mce_work; |
| static struct irq_work mce_irq_work; |
| |
| /* |
| * CPU/chipset specific EDAC code can register a notifier call here to print |
| * MCE errors in a human-readable form. |
| */ |
| BLOCKING_NOTIFIER_HEAD(x86_mce_decoder_chain); |
| |
| /* Do initial initialization of a struct mce */ |
| void mce_setup(struct mce *m) |
| { |
| memset(m, 0, sizeof(struct mce)); |
| m->cpu = m->extcpu = smp_processor_id(); |
| /* need the internal __ version to avoid deadlocks */ |
| m->time = __ktime_get_real_seconds(); |
| m->cpuvendor = boot_cpu_data.x86_vendor; |
| m->cpuid = cpuid_eax(1); |
| m->socketid = cpu_data(m->extcpu).topo.pkg_id; |
| m->apicid = cpu_data(m->extcpu).topo.initial_apicid; |
| m->mcgcap = __rdmsr(MSR_IA32_MCG_CAP); |
| m->ppin = cpu_data(m->extcpu).ppin; |
| m->microcode = boot_cpu_data.microcode; |
| } |
| |
| DEFINE_PER_CPU(struct mce, injectm); |
| EXPORT_PER_CPU_SYMBOL_GPL(injectm); |
| |
| void mce_log(struct mce *m) |
| { |
| if (!mce_gen_pool_add(m)) |
| irq_work_queue(&mce_irq_work); |
| } |
| EXPORT_SYMBOL_GPL(mce_log); |
| |
| void mce_register_decode_chain(struct notifier_block *nb) |
| { |
| if (WARN_ON(nb->priority < MCE_PRIO_LOWEST || |
| nb->priority > MCE_PRIO_HIGHEST)) |
| return; |
| |
| blocking_notifier_chain_register(&x86_mce_decoder_chain, nb); |
| } |
| EXPORT_SYMBOL_GPL(mce_register_decode_chain); |
| |
| void mce_unregister_decode_chain(struct notifier_block *nb) |
| { |
| blocking_notifier_chain_unregister(&x86_mce_decoder_chain, nb); |
| } |
| EXPORT_SYMBOL_GPL(mce_unregister_decode_chain); |
| |
| static void __print_mce(struct mce *m) |
| { |
| pr_emerg(HW_ERR "CPU %d: Machine Check%s: %Lx Bank %d: %016Lx\n", |
| m->extcpu, |
| (m->mcgstatus & MCG_STATUS_MCIP ? " Exception" : ""), |
| m->mcgstatus, m->bank, m->status); |
| |
| if (m->ip) { |
| pr_emerg(HW_ERR "RIP%s %02x:<%016Lx> ", |
| !(m->mcgstatus & MCG_STATUS_EIPV) ? " !INEXACT!" : "", |
| m->cs, m->ip); |
| |
| if (m->cs == __KERNEL_CS) |
| pr_cont("{%pS}", (void *)(unsigned long)m->ip); |
| pr_cont("\n"); |
| } |
| |
| pr_emerg(HW_ERR "TSC %llx ", m->tsc); |
| if (m->addr) |
| pr_cont("ADDR %llx ", m->addr); |
| if (m->misc) |
| pr_cont("MISC %llx ", m->misc); |
| if (m->ppin) |
| pr_cont("PPIN %llx ", m->ppin); |
| |
| if (mce_flags.smca) { |
| if (m->synd) |
| pr_cont("SYND %llx ", m->synd); |
| if (m->ipid) |
| pr_cont("IPID %llx ", m->ipid); |
| } |
| |
| pr_cont("\n"); |
| |
| /* |
| * Note this output is parsed by external tools and old fields |
| * should not be changed. |
| */ |
| pr_emerg(HW_ERR "PROCESSOR %u:%x TIME %llu SOCKET %u APIC %x microcode %x\n", |
| m->cpuvendor, m->cpuid, m->time, m->socketid, m->apicid, |
| m->microcode); |
| } |
| |
| static void print_mce(struct mce *m) |
| { |
| __print_mce(m); |
| |
| if (m->cpuvendor != X86_VENDOR_AMD && m->cpuvendor != X86_VENDOR_HYGON) |
| pr_emerg_ratelimited(HW_ERR "Run the above through 'mcelog --ascii'\n"); |
| } |
| |
| #define PANIC_TIMEOUT 5 /* 5 seconds */ |
| |
| static atomic_t mce_panicked; |
| |
| static int fake_panic; |
| static atomic_t mce_fake_panicked; |
| |
| /* Panic in progress. Enable interrupts and wait for final IPI */ |
| static void wait_for_panic(void) |
| { |
| long timeout = PANIC_TIMEOUT*USEC_PER_SEC; |
| |
| preempt_disable(); |
| local_irq_enable(); |
| while (timeout-- > 0) |
| udelay(1); |
| if (panic_timeout == 0) |
| panic_timeout = mca_cfg.panic_timeout; |
| panic("Panicing machine check CPU died"); |
| } |
| |
| static noinstr void mce_panic(const char *msg, struct mce *final, char *exp) |
| { |
| struct llist_node *pending; |
| struct mce_evt_llist *l; |
| int apei_err = 0; |
| |
| /* |
| * Allow instrumentation around external facilities usage. Not that it |
| * matters a whole lot since the machine is going to panic anyway. |
| */ |
| instrumentation_begin(); |
| |
| if (!fake_panic) { |
| /* |
| * Make sure only one CPU runs in machine check panic |
| */ |
| if (atomic_inc_return(&mce_panicked) > 1) |
| wait_for_panic(); |
| barrier(); |
| |
| bust_spinlocks(1); |
| console_verbose(); |
| } else { |
| /* Don't log too much for fake panic */ |
| if (atomic_inc_return(&mce_fake_panicked) > 1) |
| goto out; |
| } |
| pending = mce_gen_pool_prepare_records(); |
| /* First print corrected ones that are still unlogged */ |
| llist_for_each_entry(l, pending, llnode) { |
| struct mce *m = &l->mce; |
| if (!(m->status & MCI_STATUS_UC)) { |
| print_mce(m); |
| if (!apei_err) |
| apei_err = apei_write_mce(m); |
| } |
| } |
| /* Now print uncorrected but with the final one last */ |
| llist_for_each_entry(l, pending, llnode) { |
| struct mce *m = &l->mce; |
| if (!(m->status & MCI_STATUS_UC)) |
| continue; |
| if (!final || mce_cmp(m, final)) { |
| print_mce(m); |
| if (!apei_err) |
| apei_err = apei_write_mce(m); |
| } |
| } |
| if (final) { |
| print_mce(final); |
| if (!apei_err) |
| apei_err = apei_write_mce(final); |
| } |
| if (exp) |
| pr_emerg(HW_ERR "Machine check: %s\n", exp); |
| if (!fake_panic) { |
| if (panic_timeout == 0) |
| panic_timeout = mca_cfg.panic_timeout; |
| panic(msg); |
| } else |
| pr_emerg(HW_ERR "Fake kernel panic: %s\n", msg); |
| |
| out: |
| instrumentation_end(); |
| } |
| |
| /* Support code for software error injection */ |
| |
| static int msr_to_offset(u32 msr) |
| { |
| unsigned bank = __this_cpu_read(injectm.bank); |
| |
| if (msr == mca_cfg.rip_msr) |
| return offsetof(struct mce, ip); |
| if (msr == mca_msr_reg(bank, MCA_STATUS)) |
| return offsetof(struct mce, status); |
| if (msr == mca_msr_reg(bank, MCA_ADDR)) |
| return offsetof(struct mce, addr); |
| if (msr == mca_msr_reg(bank, MCA_MISC)) |
| return offsetof(struct mce, misc); |
| if (msr == MSR_IA32_MCG_STATUS) |
| return offsetof(struct mce, mcgstatus); |
| return -1; |
| } |
| |
| void ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr) |
| { |
| if (wrmsr) { |
| pr_emerg("MSR access error: WRMSR to 0x%x (tried to write 0x%08x%08x) at rIP: 0x%lx (%pS)\n", |
| (unsigned int)regs->cx, (unsigned int)regs->dx, (unsigned int)regs->ax, |
| regs->ip, (void *)regs->ip); |
| } else { |
| pr_emerg("MSR access error: RDMSR from 0x%x at rIP: 0x%lx (%pS)\n", |
| (unsigned int)regs->cx, regs->ip, (void *)regs->ip); |
| } |
| |
| show_stack_regs(regs); |
| |
| panic("MCA architectural violation!\n"); |
| |
| while (true) |
| cpu_relax(); |
| } |
| |
| /* MSR access wrappers used for error injection */ |
| noinstr u64 mce_rdmsrl(u32 msr) |
| { |
| DECLARE_ARGS(val, low, high); |
| |
| if (__this_cpu_read(injectm.finished)) { |
| int offset; |
| u64 ret; |
| |
| instrumentation_begin(); |
| |
| offset = msr_to_offset(msr); |
| if (offset < 0) |
| ret = 0; |
| else |
| ret = *(u64 *)((char *)this_cpu_ptr(&injectm) + offset); |
| |
| instrumentation_end(); |
| |
| return ret; |
| } |
| |
| /* |
| * RDMSR on MCA MSRs should not fault. If they do, this is very much an |
| * architectural violation and needs to be reported to hw vendor. Panic |
| * the box to not allow any further progress. |
| */ |
| asm volatile("1: rdmsr\n" |
| "2:\n" |
| _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_RDMSR_IN_MCE) |
| : EAX_EDX_RET(val, low, high) : "c" (msr)); |
| |
| |
| return EAX_EDX_VAL(val, low, high); |
| } |
| |
| static noinstr void mce_wrmsrl(u32 msr, u64 v) |
| { |
| u32 low, high; |
| |
| if (__this_cpu_read(injectm.finished)) { |
| int offset; |
| |
| instrumentation_begin(); |
| |
| offset = msr_to_offset(msr); |
| if (offset >= 0) |
| *(u64 *)((char *)this_cpu_ptr(&injectm) + offset) = v; |
| |
| instrumentation_end(); |
| |
| return; |
| } |
| |
| low = (u32)v; |
| high = (u32)(v >> 32); |
| |
| /* See comment in mce_rdmsrl() */ |
| asm volatile("1: wrmsr\n" |
| "2:\n" |
| _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_WRMSR_IN_MCE) |
| : : "c" (msr), "a"(low), "d" (high) : "memory"); |
| } |
| |
| /* |
| * Collect all global (w.r.t. this processor) status about this machine |
| * check into our "mce" struct so that we can use it later to assess |
| * the severity of the problem as we read per-bank specific details. |
| */ |
| static noinstr void mce_gather_info(struct mce *m, struct pt_regs *regs) |
| { |
| /* |
| * Enable instrumentation around mce_setup() which calls external |
| * facilities. |
| */ |
| instrumentation_begin(); |
| mce_setup(m); |
| instrumentation_end(); |
| |
| m->mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS); |
| if (regs) { |
| /* |
| * Get the address of the instruction at the time of |
| * the machine check error. |
| */ |
| if (m->mcgstatus & (MCG_STATUS_RIPV|MCG_STATUS_EIPV)) { |
| m->ip = regs->ip; |
| m->cs = regs->cs; |
| |
| /* |
| * When in VM86 mode make the cs look like ring 3 |
| * always. This is a lie, but it's better than passing |
| * the additional vm86 bit around everywhere. |
| */ |
| if (v8086_mode(regs)) |
| m->cs |= 3; |
| } |
| /* Use accurate RIP reporting if available. */ |
| if (mca_cfg.rip_msr) |
| m->ip = mce_rdmsrl(mca_cfg.rip_msr); |
| } |
| } |
| |
| int mce_available(struct cpuinfo_x86 *c) |
| { |
| if (mca_cfg.disabled) |
| return 0; |
| return cpu_has(c, X86_FEATURE_MCE) && cpu_has(c, X86_FEATURE_MCA); |
| } |
| |
| static void mce_schedule_work(void) |
| { |
| if (!mce_gen_pool_empty()) |
| schedule_work(&mce_work); |
| } |
| |
| static void mce_irq_work_cb(struct irq_work *entry) |
| { |
| mce_schedule_work(); |
| } |
| |
| bool mce_usable_address(struct mce *m) |
| { |
| if (!(m->status & MCI_STATUS_ADDRV)) |
| return false; |
| |
| switch (m->cpuvendor) { |
| case X86_VENDOR_AMD: |
| return amd_mce_usable_address(m); |
| |
| case X86_VENDOR_INTEL: |
| case X86_VENDOR_ZHAOXIN: |
| return intel_mce_usable_address(m); |
| |
| default: |
| return true; |
| } |
| } |
| EXPORT_SYMBOL_GPL(mce_usable_address); |
| |
| bool mce_is_memory_error(struct mce *m) |
| { |
| switch (m->cpuvendor) { |
| case X86_VENDOR_AMD: |
| case X86_VENDOR_HYGON: |
| return amd_mce_is_memory_error(m); |
| |
| case X86_VENDOR_INTEL: |
| case X86_VENDOR_ZHAOXIN: |
| /* |
| * Intel SDM Volume 3B - 15.9.2 Compound Error Codes |
| * |
| * Bit 7 of the MCACOD field of IA32_MCi_STATUS is used for |
| * indicating a memory error. Bit 8 is used for indicating a |
| * cache hierarchy error. The combination of bit 2 and bit 3 |
| * is used for indicating a `generic' cache hierarchy error |
| * But we can't just blindly check the above bits, because if |
| * bit 11 is set, then it is a bus/interconnect error - and |
| * either way the above bits just gives more detail on what |
| * bus/interconnect error happened. Note that bit 12 can be |
| * ignored, as it's the "filter" bit. |
| */ |
| return (m->status & 0xef80) == BIT(7) || |
| (m->status & 0xef00) == BIT(8) || |
| (m->status & 0xeffc) == 0xc; |
| |
| default: |
| return false; |
| } |
| } |
| EXPORT_SYMBOL_GPL(mce_is_memory_error); |
| |
| static bool whole_page(struct mce *m) |
| { |
| if (!mca_cfg.ser || !(m->status & MCI_STATUS_MISCV)) |
| return true; |
| |
| return MCI_MISC_ADDR_LSB(m->misc) >= PAGE_SHIFT; |
| } |
| |
| bool mce_is_correctable(struct mce *m) |
| { |
| if (m->cpuvendor == X86_VENDOR_AMD && m->status & MCI_STATUS_DEFERRED) |
| return false; |
| |
| if (m->cpuvendor == X86_VENDOR_HYGON && m->status & MCI_STATUS_DEFERRED) |
| return false; |
| |
| if (m->status & MCI_STATUS_UC) |
| return false; |
| |
| return true; |
| } |
| EXPORT_SYMBOL_GPL(mce_is_correctable); |
| |
| static int mce_early_notifier(struct notifier_block *nb, unsigned long val, |
| void *data) |
| { |
| struct mce *m = (struct mce *)data; |
| |
| if (!m) |
| return NOTIFY_DONE; |
| |
| /* Emit the trace record: */ |
| trace_mce_record(m); |
| |
| set_bit(0, &mce_need_notify); |
| |
| mce_notify_irq(); |
| |
| return NOTIFY_DONE; |
| } |
| |
| static struct notifier_block early_nb = { |
| .notifier_call = mce_early_notifier, |
| .priority = MCE_PRIO_EARLY, |
| }; |
| |
| static int uc_decode_notifier(struct notifier_block *nb, unsigned long val, |
| void *data) |
| { |
| struct mce *mce = (struct mce *)data; |
| unsigned long pfn; |
| |
| if (!mce || !mce_usable_address(mce)) |
| return NOTIFY_DONE; |
| |
| if (mce->severity != MCE_AO_SEVERITY && |
| mce->severity != MCE_DEFERRED_SEVERITY) |
| return NOTIFY_DONE; |
| |
| pfn = (mce->addr & MCI_ADDR_PHYSADDR) >> PAGE_SHIFT; |
| if (!memory_failure(pfn, 0)) { |
| set_mce_nospec(pfn); |
| mce->kflags |= MCE_HANDLED_UC; |
| } |
| |
| return NOTIFY_OK; |
| } |
| |
| static struct notifier_block mce_uc_nb = { |
| .notifier_call = uc_decode_notifier, |
| .priority = MCE_PRIO_UC, |
| }; |
| |
| static int mce_default_notifier(struct notifier_block *nb, unsigned long val, |
| void *data) |
| { |
| struct mce *m = (struct mce *)data; |
| |
| if (!m) |
| return NOTIFY_DONE; |
| |
| if (mca_cfg.print_all || !m->kflags) |
| __print_mce(m); |
| |
| return NOTIFY_DONE; |
| } |
| |
| static struct notifier_block mce_default_nb = { |
| .notifier_call = mce_default_notifier, |
| /* lowest prio, we want it to run last. */ |
| .priority = MCE_PRIO_LOWEST, |
| }; |
| |
| /* |
| * Read ADDR and MISC registers. |
| */ |
| static noinstr void mce_read_aux(struct mce *m, int i) |
| { |
| if (m->status & MCI_STATUS_MISCV) |
| m->misc = mce_rdmsrl(mca_msr_reg(i, MCA_MISC)); |
| |
| if (m->status & MCI_STATUS_ADDRV) { |
| m->addr = mce_rdmsrl(mca_msr_reg(i, MCA_ADDR)); |
| |
| /* |
| * Mask the reported address by the reported granularity. |
| */ |
| if (mca_cfg.ser && (m->status & MCI_STATUS_MISCV)) { |
| u8 shift = MCI_MISC_ADDR_LSB(m->misc); |
| m->addr >>= shift; |
| m->addr <<= shift; |
| } |
| |
| smca_extract_err_addr(m); |
| } |
| |
| if (mce_flags.smca) { |
| m->ipid = mce_rdmsrl(MSR_AMD64_SMCA_MCx_IPID(i)); |
| |
| if (m->status & MCI_STATUS_SYNDV) |
| m->synd = mce_rdmsrl(MSR_AMD64_SMCA_MCx_SYND(i)); |
| } |
| } |
| |
| DEFINE_PER_CPU(unsigned, mce_poll_count); |
| |
| /* |
| * Poll for corrected events or events that happened before reset. |
| * Those are just logged through /dev/mcelog. |
| * |
| * This is executed in standard interrupt context. |
| * |
| * Note: spec recommends to panic for fatal unsignalled |
| * errors here. However this would be quite problematic -- |
| * we would need to reimplement the Monarch handling and |
| * it would mess up the exclusion between exception handler |
| * and poll handler -- * so we skip this for now. |
| * These cases should not happen anyways, or only when the CPU |
| * is already totally * confused. In this case it's likely it will |
| * not fully execute the machine check handler either. |
| */ |
| bool machine_check_poll(enum mcp_flags flags, mce_banks_t *b) |
| { |
| struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array); |
| bool error_seen = false; |
| struct mce m; |
| int i; |
| |
| this_cpu_inc(mce_poll_count); |
| |
| mce_gather_info(&m, NULL); |
| |
| if (flags & MCP_TIMESTAMP) |
| m.tsc = rdtsc(); |
| |
| for (i = 0; i < this_cpu_read(mce_num_banks); i++) { |
| if (!mce_banks[i].ctl || !test_bit(i, *b)) |
| continue; |
| |
| m.misc = 0; |
| m.addr = 0; |
| m.bank = i; |
| |
| barrier(); |
| m.status = mce_rdmsrl(mca_msr_reg(i, MCA_STATUS)); |
| |
| /* If this entry is not valid, ignore it */ |
| if (!(m.status & MCI_STATUS_VAL)) |
| continue; |
| |
| /* |
| * If we are logging everything (at CPU online) or this |
| * is a corrected error, then we must log it. |
| */ |
| if ((flags & MCP_UC) || !(m.status & MCI_STATUS_UC)) |
| goto log_it; |
| |
| /* |
| * Newer Intel systems that support software error |
| * recovery need to make additional checks. Other |
| * CPUs should skip over uncorrected errors, but log |
| * everything else. |
| */ |
| if (!mca_cfg.ser) { |
| if (m.status & MCI_STATUS_UC) |
| continue; |
| goto log_it; |
| } |
| |
| /* Log "not enabled" (speculative) errors */ |
| if (!(m.status & MCI_STATUS_EN)) |
| goto log_it; |
| |
| /* |
| * Log UCNA (SDM: 15.6.3 "UCR Error Classification") |
| * UC == 1 && PCC == 0 && S == 0 |
| */ |
| if (!(m.status & MCI_STATUS_PCC) && !(m.status & MCI_STATUS_S)) |
| goto log_it; |
| |
| /* |
| * Skip anything else. Presumption is that our read of this |
| * bank is racing with a machine check. Leave the log alone |
| * for do_machine_check() to deal with it. |
| */ |
| continue; |
| |
| log_it: |
| error_seen = true; |
| |
| if (flags & MCP_DONTLOG) |
| goto clear_it; |
| |
| mce_read_aux(&m, i); |
| m.severity = mce_severity(&m, NULL, NULL, false); |
| /* |
| * Don't get the IP here because it's unlikely to |
| * have anything to do with the actual error location. |
| */ |
| |
| if (mca_cfg.dont_log_ce && !mce_usable_address(&m)) |
| goto clear_it; |
| |
| if (flags & MCP_QUEUE_LOG) |
| mce_gen_pool_add(&m); |
| else |
| mce_log(&m); |
| |
| clear_it: |
| /* |
| * Clear state for this bank. |
| */ |
| mce_wrmsrl(mca_msr_reg(i, MCA_STATUS), 0); |
| } |
| |
| /* |
| * Don't clear MCG_STATUS here because it's only defined for |
| * exceptions. |
| */ |
| |
| sync_core(); |
| |
| return error_seen; |
| } |
| EXPORT_SYMBOL_GPL(machine_check_poll); |
| |
| /* |
| * During IFU recovery Sandy Bridge -EP4S processors set the RIPV and |
| * EIPV bits in MCG_STATUS to zero on the affected logical processor (SDM |
| * Vol 3B Table 15-20). But this confuses both the code that determines |
| * whether the machine check occurred in kernel or user mode, and also |
| * the severity assessment code. Pretend that EIPV was set, and take the |
| * ip/cs values from the pt_regs that mce_gather_info() ignored earlier. |
| */ |
| static __always_inline void |
| quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs) |
| { |
| if (bank != 0) |
| return; |
| if ((m->mcgstatus & (MCG_STATUS_EIPV|MCG_STATUS_RIPV)) != 0) |
| return; |
| if ((m->status & (MCI_STATUS_OVER|MCI_STATUS_UC| |
| MCI_STATUS_EN|MCI_STATUS_MISCV|MCI_STATUS_ADDRV| |
| MCI_STATUS_PCC|MCI_STATUS_S|MCI_STATUS_AR| |
| MCACOD)) != |
| (MCI_STATUS_UC|MCI_STATUS_EN| |
| MCI_STATUS_MISCV|MCI_STATUS_ADDRV|MCI_STATUS_S| |
| MCI_STATUS_AR|MCACOD_INSTR)) |
| return; |
| |
| m->mcgstatus |= MCG_STATUS_EIPV; |
| m->ip = regs->ip; |
| m->cs = regs->cs; |
| } |
| |
| /* |
| * Disable fast string copy and return from the MCE handler upon the first SRAR |
| * MCE on bank 1 due to a CPU erratum on Intel Skylake/Cascade Lake/Cooper Lake |
| * CPUs. |
| * The fast string copy instructions ("REP; MOVS*") could consume an |
| * uncorrectable memory error in the cache line _right after_ the desired region |
| * to copy and raise an MCE with RIP pointing to the instruction _after_ the |
| * "REP; MOVS*". |
| * This mitigation addresses the issue completely with the caveat of performance |
| * degradation on the CPU affected. This is still better than the OS crashing on |
| * MCEs raised on an irrelevant process due to "REP; MOVS*" accesses from a |
| * kernel context (e.g., copy_page). |
| * |
| * Returns true when fast string copy on CPU has been disabled. |
| */ |
| static noinstr bool quirk_skylake_repmov(void) |
| { |
| u64 mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS); |
| u64 misc_enable = mce_rdmsrl(MSR_IA32_MISC_ENABLE); |
| u64 mc1_status; |
| |
| /* |
| * Apply the quirk only to local machine checks, i.e., no broadcast |
| * sync is needed. |
| */ |
| if (!(mcgstatus & MCG_STATUS_LMCES) || |
| !(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) |
| return false; |
| |
| mc1_status = mce_rdmsrl(MSR_IA32_MCx_STATUS(1)); |
| |
| /* Check for a software-recoverable data fetch error. */ |
| if ((mc1_status & |
| (MCI_STATUS_VAL | MCI_STATUS_OVER | MCI_STATUS_UC | MCI_STATUS_EN | |
| MCI_STATUS_ADDRV | MCI_STATUS_MISCV | MCI_STATUS_PCC | |
| MCI_STATUS_AR | MCI_STATUS_S)) == |
| (MCI_STATUS_VAL | MCI_STATUS_UC | MCI_STATUS_EN | |
| MCI_STATUS_ADDRV | MCI_STATUS_MISCV | |
| MCI_STATUS_AR | MCI_STATUS_S)) { |
| misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING; |
| mce_wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable); |
| mce_wrmsrl(MSR_IA32_MCx_STATUS(1), 0); |
| |
| instrumentation_begin(); |
| pr_err_once("Erratum detected, disable fast string copy instructions.\n"); |
| instrumentation_end(); |
| |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* |
| * Some Zen-based Instruction Fetch Units set EIPV=RIPV=0 on poison consumption |
| * errors. This means mce_gather_info() will not save the "ip" and "cs" registers. |
| * |
| * However, the context is still valid, so save the "cs" register for later use. |
| * |
| * The "ip" register is truly unknown, so don't save it or fixup EIPV/RIPV. |
| * |
| * The Instruction Fetch Unit is at MCA bank 1 for all affected systems. |
| */ |
| static __always_inline void quirk_zen_ifu(int bank, struct mce *m, struct pt_regs *regs) |
| { |
| if (bank != 1) |
| return; |
| if (!(m->status & MCI_STATUS_POISON)) |
| return; |
| |
| m->cs = regs->cs; |
| } |
| |
| /* |
| * Do a quick check if any of the events requires a panic. |
| * This decides if we keep the events around or clear them. |
| */ |
| static __always_inline int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp, |
| struct pt_regs *regs) |
| { |
| char *tmp = *msg; |
| int i; |
| |
| for (i = 0; i < this_cpu_read(mce_num_banks); i++) { |
| m->status = mce_rdmsrl(mca_msr_reg(i, MCA_STATUS)); |
| if (!(m->status & MCI_STATUS_VAL)) |
| continue; |
| |
| arch___set_bit(i, validp); |
| if (mce_flags.snb_ifu_quirk) |
| quirk_sandybridge_ifu(i, m, regs); |
| |
| if (mce_flags.zen_ifu_quirk) |
| quirk_zen_ifu(i, m, regs); |
| |
| m->bank = i; |
| if (mce_severity(m, regs, &tmp, true) >= MCE_PANIC_SEVERITY) { |
| mce_read_aux(m, i); |
| *msg = tmp; |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| * Variable to establish order between CPUs while scanning. |
| * Each CPU spins initially until executing is equal its number. |
| */ |
| static atomic_t mce_executing; |
| |
| /* |
| * Defines order of CPUs on entry. First CPU becomes Monarch. |
| */ |
| static atomic_t mce_callin; |
| |
| /* |
| * Track which CPUs entered the MCA broadcast synchronization and which not in |
| * order to print holdouts. |
| */ |
| static cpumask_t mce_missing_cpus = CPU_MASK_ALL; |
| |
| /* |
| * Check if a timeout waiting for other CPUs happened. |
| */ |
| static noinstr int mce_timed_out(u64 *t, const char *msg) |
| { |
| int ret = 0; |
| |
| /* Enable instrumentation around calls to external facilities */ |
| instrumentation_begin(); |
| |
| /* |
| * The others already did panic for some reason. |
| * Bail out like in a timeout. |
| * rmb() to tell the compiler that system_state |
| * might have been modified by someone else. |
| */ |
| rmb(); |
| if (atomic_read(&mce_panicked)) |
| wait_for_panic(); |
| if (!mca_cfg.monarch_timeout) |
| goto out; |
| if ((s64)*t < SPINUNIT) { |
| if (cpumask_and(&mce_missing_cpus, cpu_online_mask, &mce_missing_cpus)) |
| pr_emerg("CPUs not responding to MCE broadcast (may include false positives): %*pbl\n", |
| cpumask_pr_args(&mce_missing_cpus)); |
| mce_panic(msg, NULL, NULL); |
| |
| ret = 1; |
| goto out; |
| } |
| *t -= SPINUNIT; |
| |
| out: |
| touch_nmi_watchdog(); |
| |
| instrumentation_end(); |
| |
| return ret; |
| } |
| |
| /* |
| * The Monarch's reign. The Monarch is the CPU who entered |
| * the machine check handler first. It waits for the others to |
| * raise the exception too and then grades them. When any |
| * error is fatal panic. Only then let the others continue. |
| * |
| * The other CPUs entering the MCE handler will be controlled by the |
| * Monarch. They are called Subjects. |
| * |
| * This way we prevent any potential data corruption in a unrecoverable case |
| * and also makes sure always all CPU's errors are examined. |
| * |
| * Also this detects the case of a machine check event coming from outer |
| * space (not detected by any CPUs) In this case some external agent wants |
| * us to shut down, so panic too. |
| * |
| * The other CPUs might still decide to panic if the handler happens |
| * in a unrecoverable place, but in this case the system is in a semi-stable |
| * state and won't corrupt anything by itself. It's ok to let the others |
| * continue for a bit first. |
| * |
| * All the spin loops have timeouts; when a timeout happens a CPU |
| * typically elects itself to be Monarch. |
| */ |
| static void mce_reign(void) |
| { |
| int cpu; |
| struct mce *m = NULL; |
| int global_worst = 0; |
| char *msg = NULL; |
| |
| /* |
| * This CPU is the Monarch and the other CPUs have run |
| * through their handlers. |
| * Grade the severity of the errors of all the CPUs. |
| */ |
| for_each_possible_cpu(cpu) { |
| struct mce *mtmp = &per_cpu(mces_seen, cpu); |
| |
| if (mtmp->severity > global_worst) { |
| global_worst = mtmp->severity; |
| m = &per_cpu(mces_seen, cpu); |
| } |
| } |
| |
| /* |
| * Cannot recover? Panic here then. |
| * This dumps all the mces in the log buffer and stops the |
| * other CPUs. |
| */ |
| if (m && global_worst >= MCE_PANIC_SEVERITY) { |
| /* call mce_severity() to get "msg" for panic */ |
| mce_severity(m, NULL, &msg, true); |
| mce_panic("Fatal machine check", m, msg); |
| } |
| |
| /* |
| * For UC somewhere we let the CPU who detects it handle it. |
| * Also must let continue the others, otherwise the handling |
| * CPU could deadlock on a lock. |
| */ |
| |
| /* |
| * No machine check event found. Must be some external |
| * source or one CPU is hung. Panic. |
| */ |
| if (global_worst <= MCE_KEEP_SEVERITY) |
| mce_panic("Fatal machine check from unknown source", NULL, NULL); |
| |
| /* |
| * Now clear all the mces_seen so that they don't reappear on |
| * the next mce. |
| */ |
| for_each_possible_cpu(cpu) |
| memset(&per_cpu(mces_seen, cpu), 0, sizeof(struct mce)); |
| } |
| |
| static atomic_t global_nwo; |
| |
| /* |
| * Start of Monarch synchronization. This waits until all CPUs have |
| * entered the exception handler and then determines if any of them |
| * saw a fatal event that requires panic. Then it executes them |
| * in the entry order. |
| * TBD double check parallel CPU hotunplug |
| */ |
| static noinstr int mce_start(int *no_way_out) |
| { |
| u64 timeout = (u64)mca_cfg.monarch_timeout * NSEC_PER_USEC; |
| int order, ret = -1; |
| |
| if (!timeout) |
| return ret; |
| |
| raw_atomic_add(*no_way_out, &global_nwo); |
| /* |
| * Rely on the implied barrier below, such that global_nwo |
| * is updated before mce_callin. |
| */ |
| order = raw_atomic_inc_return(&mce_callin); |
| arch_cpumask_clear_cpu(smp_processor_id(), &mce_missing_cpus); |
| |
| /* Enable instrumentation around calls to external facilities */ |
| instrumentation_begin(); |
| |
| /* |
| * Wait for everyone. |
| */ |
| while (raw_atomic_read(&mce_callin) != num_online_cpus()) { |
| if (mce_timed_out(&timeout, |
| "Timeout: Not all CPUs entered broadcast exception handler")) { |
| raw_atomic_set(&global_nwo, 0); |
| goto out; |
| } |
| ndelay(SPINUNIT); |
| } |
| |
| /* |
| * mce_callin should be read before global_nwo |
| */ |
| smp_rmb(); |
| |
| if (order == 1) { |
| /* |
| * Monarch: Starts executing now, the others wait. |
| */ |
| raw_atomic_set(&mce_executing, 1); |
| } else { |
| /* |
| * Subject: Now start the scanning loop one by one in |
| * the original callin order. |
| * This way when there are any shared banks it will be |
| * only seen by one CPU before cleared, avoiding duplicates. |
| */ |
| while (raw_atomic_read(&mce_executing) < order) { |
| if (mce_timed_out(&timeout, |
| "Timeout: Subject CPUs unable to finish machine check processing")) { |
| raw_atomic_set(&global_nwo, 0); |
| goto out; |
| } |
| ndelay(SPINUNIT); |
| } |
| } |
| |
| /* |
| * Cache the global no_way_out state. |
| */ |
| *no_way_out = raw_atomic_read(&global_nwo); |
| |
| ret = order; |
| |
| out: |
| instrumentation_end(); |
| |
| return ret; |
| } |
| |
| /* |
| * Synchronize between CPUs after main scanning loop. |
| * This invokes the bulk of the Monarch processing. |
| */ |
| static noinstr int mce_end(int order) |
| { |
| u64 timeout = (u64)mca_cfg.monarch_timeout * NSEC_PER_USEC; |
| int ret = -1; |
| |
| /* Allow instrumentation around external facilities. */ |
| instrumentation_begin(); |
| |
| if (!timeout) |
| goto reset; |
| if (order < 0) |
| goto reset; |
| |
| /* |
| * Allow others to run. |
| */ |
| atomic_inc(&mce_executing); |
| |
| if (order == 1) { |
| /* |
| * Monarch: Wait for everyone to go through their scanning |
| * loops. |
| */ |
| while (atomic_read(&mce_executing) <= num_online_cpus()) { |
| if (mce_timed_out(&timeout, |
| "Timeout: Monarch CPU unable to finish machine check processing")) |
| goto reset; |
| ndelay(SPINUNIT); |
| } |
| |
| mce_reign(); |
| barrier(); |
| ret = 0; |
| } else { |
| /* |
| * Subject: Wait for Monarch to finish. |
| */ |
| while (atomic_read(&mce_executing) != 0) { |
| if (mce_timed_out(&timeout, |
| "Timeout: Monarch CPU did not finish machine check processing")) |
| goto reset; |
| ndelay(SPINUNIT); |
| } |
| |
| /* |
| * Don't reset anything. That's done by the Monarch. |
| */ |
| ret = 0; |
| goto out; |
| } |
| |
| /* |
| * Reset all global state. |
| */ |
| reset: |
| atomic_set(&global_nwo, 0); |
| atomic_set(&mce_callin, 0); |
| cpumask_setall(&mce_missing_cpus); |
| barrier(); |
| |
| /* |
| * Let others run again. |
| */ |
| atomic_set(&mce_executing, 0); |
| |
| out: |
| instrumentation_end(); |
| |
| return ret; |
| } |
| |
| static __always_inline void mce_clear_state(unsigned long *toclear) |
| { |
| int i; |
| |
| for (i = 0; i < this_cpu_read(mce_num_banks); i++) { |
| if (arch_test_bit(i, toclear)) |
| mce_wrmsrl(mca_msr_reg(i, MCA_STATUS), 0); |
| } |
| } |
| |
| /* |
| * Cases where we avoid rendezvous handler timeout: |
| * 1) If this CPU is offline. |
| * |
| * 2) If crashing_cpu was set, e.g. we're entering kdump and we need to |
| * skip those CPUs which remain looping in the 1st kernel - see |
| * crash_nmi_callback(). |
| * |
| * Note: there still is a small window between kexec-ing and the new, |
| * kdump kernel establishing a new #MC handler where a broadcasted MCE |
| * might not get handled properly. |
| */ |
| static noinstr bool mce_check_crashing_cpu(void) |
| { |
| unsigned int cpu = smp_processor_id(); |
| |
| if (arch_cpu_is_offline(cpu) || |
| (crashing_cpu != -1 && crashing_cpu != cpu)) { |
| u64 mcgstatus; |
| |
| mcgstatus = __rdmsr(MSR_IA32_MCG_STATUS); |
| |
| if (boot_cpu_data.x86_vendor == X86_VENDOR_ZHAOXIN) { |
| if (mcgstatus & MCG_STATUS_LMCES) |
| return false; |
| } |
| |
| if (mcgstatus & MCG_STATUS_RIPV) { |
| __wrmsr(MSR_IA32_MCG_STATUS, 0, 0); |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| static __always_inline int |
| __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *final, |
| unsigned long *toclear, unsigned long *valid_banks, int no_way_out, |
| int *worst) |
| { |
| struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array); |
| struct mca_config *cfg = &mca_cfg; |
| int severity, i, taint = 0; |
| |
| for (i = 0; i < this_cpu_read(mce_num_banks); i++) { |
| arch___clear_bit(i, toclear); |
| if (!arch_test_bit(i, valid_banks)) |
| continue; |
| |
| if (!mce_banks[i].ctl) |
| continue; |
| |
| m->misc = 0; |
| m->addr = 0; |
| m->bank = i; |
| |
| m->status = mce_rdmsrl(mca_msr_reg(i, MCA_STATUS)); |
| if (!(m->status & MCI_STATUS_VAL)) |
| continue; |
| |
| /* |
| * Corrected or non-signaled errors are handled by |
| * machine_check_poll(). Leave them alone, unless this panics. |
| */ |
| if (!(m->status & (cfg->ser ? MCI_STATUS_S : MCI_STATUS_UC)) && |
| !no_way_out) |
| continue; |
| |
| /* Set taint even when machine check was not enabled. */ |
| taint++; |
| |
| severity = mce_severity(m, regs, NULL, true); |
| |
| /* |
| * When machine check was for corrected/deferred handler don't |
| * touch, unless we're panicking. |
| */ |
| if ((severity == MCE_KEEP_SEVERITY || |
| severity == MCE_UCNA_SEVERITY) && !no_way_out) |
| continue; |
| |
| arch___set_bit(i, toclear); |
| |
| /* Machine check event was not enabled. Clear, but ignore. */ |
| if (severity == MCE_NO_SEVERITY) |
| continue; |
| |
| mce_read_aux(m, i); |
| |
| /* assuming valid severity level != 0 */ |
| m->severity = severity; |
| |
| /* |
| * Enable instrumentation around the mce_log() call which is |
| * done in #MC context, where instrumentation is disabled. |
| */ |
| instrumentation_begin(); |
| mce_log(m); |
| instrumentation_end(); |
| |
| if (severity > *worst) { |
| *final = *m; |
| *worst = severity; |
| } |
| } |
| |
| /* mce_clear_state will clear *final, save locally for use later */ |
| *m = *final; |
| |
| return taint; |
| } |
| |
| static void kill_me_now(struct callback_head *ch) |
| { |
| struct task_struct *p = container_of(ch, struct task_struct, mce_kill_me); |
| |
| p->mce_count = 0; |
| force_sig(SIGBUS); |
| } |
| |
| static void kill_me_maybe(struct callback_head *cb) |
| { |
| struct task_struct *p = container_of(cb, struct task_struct, mce_kill_me); |
| int flags = MF_ACTION_REQUIRED; |
| unsigned long pfn; |
| int ret; |
| |
| p->mce_count = 0; |
| pr_err("Uncorrected hardware memory error in user-access at %llx", p->mce_addr); |
| |
| if (!p->mce_ripv) |
| flags |= MF_MUST_KILL; |
| |
| pfn = (p->mce_addr & MCI_ADDR_PHYSADDR) >> PAGE_SHIFT; |
| ret = memory_failure(pfn, flags); |
| if (!ret) { |
| set_mce_nospec(pfn); |
| sync_core(); |
| return; |
| } |
| |
| /* |
| * -EHWPOISON from memory_failure() means that it already sent SIGBUS |
| * to the current process with the proper error info, |
| * -EOPNOTSUPP means hwpoison_filter() filtered the error event, |
| * |
| * In both cases, no further processing is required. |
| */ |
| if (ret == -EHWPOISON || ret == -EOPNOTSUPP) |
| return; |
| |
| pr_err("Memory error not recovered"); |
| kill_me_now(cb); |
| } |
| |
| static void kill_me_never(struct callback_head *cb) |
| { |
| struct task_struct *p = container_of(cb, struct task_struct, mce_kill_me); |
| unsigned long pfn; |
| |
| p->mce_count = 0; |
| pr_err("Kernel accessed poison in user space at %llx\n", p->mce_addr); |
| pfn = (p->mce_addr & MCI_ADDR_PHYSADDR) >> PAGE_SHIFT; |
| if (!memory_failure(pfn, 0)) |
| set_mce_nospec(pfn); |
| } |
| |
| static void queue_task_work(struct mce *m, char *msg, void (*func)(struct callback_head *)) |
| { |
| int count = ++current->mce_count; |
| |
| /* First call, save all the details */ |
| if (count == 1) { |
| current->mce_addr = m->addr; |
| current->mce_kflags = m->kflags; |
| current->mce_ripv = !!(m->mcgstatus & MCG_STATUS_RIPV); |
| current->mce_whole_page = whole_page(m); |
| current->mce_kill_me.func = func; |
| } |
| |
| /* Ten is likely overkill. Don't expect more than two faults before task_work() */ |
| if (count > 10) |
| mce_panic("Too many consecutive machine checks while accessing user data", m, msg); |
| |
| /* Second or later call, make sure page address matches the one from first call */ |
| if (count > 1 && (current->mce_addr >> PAGE_SHIFT) != (m->addr >> PAGE_SHIFT)) |
| mce_panic("Consecutive machine checks to different user pages", m, msg); |
| |
| /* Do not call task_work_add() more than once */ |
| if (count > 1) |
| return; |
| |
| task_work_add(current, ¤t->mce_kill_me, TWA_RESUME); |
| } |
| |
| /* Handle unconfigured int18 (should never happen) */ |
| static noinstr void unexpected_machine_check(struct pt_regs *regs) |
| { |
| instrumentation_begin(); |
| pr_err("CPU#%d: Unexpected int18 (Machine Check)\n", |
| smp_processor_id()); |
| instrumentation_end(); |
| } |
| |
| /* |
| * The actual machine check handler. This only handles real exceptions when |
| * something got corrupted coming in through int 18. |
| * |
| * This is executed in #MC context not subject to normal locking rules. |
| * This implies that most kernel services cannot be safely used. Don't even |
| * think about putting a printk in there! |
| * |
| * On Intel systems this is entered on all CPUs in parallel through |
| * MCE broadcast. However some CPUs might be broken beyond repair, |
| * so be always careful when synchronizing with others. |
| * |
| * Tracing and kprobes are disabled: if we interrupted a kernel context |
| * with IF=1, we need to minimize stack usage. There are also recursion |
| * issues: if the machine check was due to a failure of the memory |
| * backing the user stack, tracing that reads the user stack will cause |
| * potentially infinite recursion. |
| * |
| * Currently, the #MC handler calls out to a number of external facilities |
| * and, therefore, allows instrumentation around them. The optimal thing to |
| * have would be to do the absolutely minimal work required in #MC context |
| * and have instrumentation disabled only around that. Further processing can |
| * then happen in process context where instrumentation is allowed. Achieving |
| * that requires careful auditing and modifications. Until then, the code |
| * allows instrumentation temporarily, where required. * |
| */ |
| noinstr void do_machine_check(struct pt_regs *regs) |
| { |
| int worst = 0, order, no_way_out, kill_current_task, lmce, taint = 0; |
| DECLARE_BITMAP(valid_banks, MAX_NR_BANKS) = { 0 }; |
| DECLARE_BITMAP(toclear, MAX_NR_BANKS) = { 0 }; |
| struct mce m, *final; |
| char *msg = NULL; |
| |
| if (unlikely(mce_flags.p5)) |
| return pentium_machine_check(regs); |
| else if (unlikely(mce_flags.winchip)) |
| return winchip_machine_check(regs); |
| else if (unlikely(!mca_cfg.initialized)) |
| return unexpected_machine_check(regs); |
| |
| if (mce_flags.skx_repmov_quirk && quirk_skylake_repmov()) |
| goto clear; |
| |
| /* |
| * Establish sequential order between the CPUs entering the machine |
| * check handler. |
| */ |
| order = -1; |
| |
| /* |
| * If no_way_out gets set, there is no safe way to recover from this |
| * MCE. |
| */ |
| no_way_out = 0; |
| |
| /* |
| * If kill_current_task is not set, there might be a way to recover from this |
| * error. |
| */ |
| kill_current_task = 0; |
| |
| /* |
| * MCEs are always local on AMD. Same is determined by MCG_STATUS_LMCES |
| * on Intel. |
| */ |
| lmce = 1; |
| |
| this_cpu_inc(mce_exception_count); |
| |
| mce_gather_info(&m, regs); |
| m.tsc = rdtsc(); |
| |
| final = this_cpu_ptr(&mces_seen); |
| *final = m; |
| |
| no_way_out = mce_no_way_out(&m, &msg, valid_banks, regs); |
| |
| barrier(); |
| |
| /* |
| * When no restart IP might need to kill or panic. |
| * Assume the worst for now, but if we find the |
| * severity is MCE_AR_SEVERITY we have other options. |
| */ |
| if (!(m.mcgstatus & MCG_STATUS_RIPV)) |
| kill_current_task = 1; |
| /* |
| * Check if this MCE is signaled to only this logical processor, |
| * on Intel, Zhaoxin only. |
| */ |
| if (m.cpuvendor == X86_VENDOR_INTEL || |
| m.cpuvendor == X86_VENDOR_ZHAOXIN) |
| lmce = m.mcgstatus & MCG_STATUS_LMCES; |
| |
| /* |
| * Local machine check may already know that we have to panic. |
| * Broadcast machine check begins rendezvous in mce_start() |
| * Go through all banks in exclusion of the other CPUs. This way we |
| * don't report duplicated events on shared banks because the first one |
| * to see it will clear it. |
| */ |
| if (lmce) { |
| if (no_way_out) |
| mce_panic("Fatal local machine check", &m, msg); |
| } else { |
| order = mce_start(&no_way_out); |
| } |
| |
| taint = __mc_scan_banks(&m, regs, final, toclear, valid_banks, no_way_out, &worst); |
| |
| if (!no_way_out) |
| mce_clear_state(toclear); |
| |
| /* |
| * Do most of the synchronization with other CPUs. |
| * When there's any problem use only local no_way_out state. |
| */ |
| if (!lmce) { |
| if (mce_end(order) < 0) { |
| if (!no_way_out) |
| no_way_out = worst >= MCE_PANIC_SEVERITY; |
| |
| if (no_way_out) |
| mce_panic("Fatal machine check on current CPU", &m, msg); |
| } |
| } else { |
| /* |
| * If there was a fatal machine check we should have |
| * already called mce_panic earlier in this function. |
| * Since we re-read the banks, we might have found |
| * something new. Check again to see if we found a |
| * fatal error. We call "mce_severity()" again to |
| * make sure we have the right "msg". |
| */ |
| if (worst >= MCE_PANIC_SEVERITY) { |
| mce_severity(&m, regs, &msg, true); |
| mce_panic("Local fatal machine check!", &m, msg); |
| } |
| } |
| |
| /* |
| * Enable instrumentation around the external facilities like task_work_add() |
| * (via queue_task_work()), fixup_exception() etc. For now, that is. Fixing this |
| * properly would need a lot more involved reorganization. |
| */ |
| instrumentation_begin(); |
| |
| if (taint) |
| add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); |
| |
| if (worst != MCE_AR_SEVERITY && !kill_current_task) |
| goto out; |
| |
| /* Fault was in user mode and we need to take some action */ |
| if ((m.cs & 3) == 3) { |
| /* If this triggers there is no way to recover. Die hard. */ |
| BUG_ON(!on_thread_stack() || !user_mode(regs)); |
| |
| if (!mce_usable_address(&m)) |
| queue_task_work(&m, msg, kill_me_now); |
| else |
| queue_task_work(&m, msg, kill_me_maybe); |
| |
| } else { |
| /* |
| * Handle an MCE which has happened in kernel space but from |
| * which the kernel can recover: ex_has_fault_handler() has |
| * already verified that the rIP at which the error happened is |
| * a rIP from which the kernel can recover (by jumping to |
| * recovery code specified in _ASM_EXTABLE_FAULT()) and the |
| * corresponding exception handler which would do that is the |
| * proper one. |
| */ |
| if (m.kflags & MCE_IN_KERNEL_RECOV) { |
| if (!fixup_exception(regs, X86_TRAP_MC, 0, 0)) |
| mce_panic("Failed kernel mode recovery", &m, msg); |
| } |
| |
| if (m.kflags & MCE_IN_KERNEL_COPYIN) |
| queue_task_work(&m, msg, kill_me_never); |
| } |
| |
| out: |
| instrumentation_end(); |
| |
| clear: |
| mce_wrmsrl(MSR_IA32_MCG_STATUS, 0); |
| } |
| EXPORT_SYMBOL_GPL(do_machine_check); |
| |
| #ifndef CONFIG_MEMORY_FAILURE |
| int memory_failure(unsigned long pfn, int flags) |
| { |
| /* mce_severity() should not hand us an ACTION_REQUIRED error */ |
| BUG_ON(flags & MF_ACTION_REQUIRED); |
| pr_err("Uncorrected memory error in page 0x%lx ignored\n" |
| "Rebuild kernel with CONFIG_MEMORY_FAILURE=y for smarter handling\n", |
| pfn); |
| |
| return 0; |
| } |
| #endif |
| |
| /* |
| * Periodic polling timer for "silent" machine check errors. If the |
| * poller finds an MCE, poll 2x faster. When the poller finds no more |
| * errors, poll 2x slower (up to check_interval seconds). |
| */ |
| static unsigned long check_interval = INITIAL_CHECK_INTERVAL; |
| |
| static DEFINE_PER_CPU(unsigned long, mce_next_interval); /* in jiffies */ |
| static DEFINE_PER_CPU(struct timer_list, mce_timer); |
| |
| static unsigned long mce_adjust_timer_default(unsigned long interval) |
| { |
| return interval; |
| } |
| |
| static unsigned long (*mce_adjust_timer)(unsigned long interval) = mce_adjust_timer_default; |
| |
| static void __start_timer(struct timer_list *t, unsigned long interval) |
| { |
| unsigned long when = jiffies + interval; |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| |
| if (!timer_pending(t) || time_before(when, t->expires)) |
| mod_timer(t, round_jiffies(when)); |
| |
| local_irq_restore(flags); |
| } |
| |
| static void mc_poll_banks_default(void) |
| { |
| machine_check_poll(0, this_cpu_ptr(&mce_poll_banks)); |
| } |
| |
| void (*mc_poll_banks)(void) = mc_poll_banks_default; |
| |
| static void mce_timer_fn(struct timer_list *t) |
| { |
| struct timer_list *cpu_t = this_cpu_ptr(&mce_timer); |
| unsigned long iv; |
| |
| WARN_ON(cpu_t != t); |
| |
| iv = __this_cpu_read(mce_next_interval); |
| |
| if (mce_available(this_cpu_ptr(&cpu_info))) { |
| mc_poll_banks(); |
| |
| if (mce_intel_cmci_poll()) { |
| iv = mce_adjust_timer(iv); |
| goto done; |
| } |
| } |
| |
| /* |
| * Alert userspace if needed. If we logged an MCE, reduce the polling |
| * interval, otherwise increase the polling interval. |
| */ |
| if (mce_notify_irq()) |
| iv = max(iv / 2, (unsigned long) HZ/100); |
| else |
| iv = min(iv * 2, round_jiffies_relative(check_interval * HZ)); |
| |
| done: |
| __this_cpu_write(mce_next_interval, iv); |
| __start_timer(t, iv); |
| } |
| |
| /* |
| * Ensure that the timer is firing in @interval from now. |
| */ |
| void mce_timer_kick(unsigned long interval) |
| { |
| struct timer_list *t = this_cpu_ptr(&mce_timer); |
| unsigned long iv = __this_cpu_read(mce_next_interval); |
| |
| __start_timer(t, interval); |
| |
| if (interval < iv) |
| __this_cpu_write(mce_next_interval, interval); |
| } |
| |
| /* Must not be called in IRQ context where del_timer_sync() can deadlock */ |
| static void mce_timer_delete_all(void) |
| { |
| int cpu; |
| |
| for_each_online_cpu(cpu) |
| del_timer_sync(&per_cpu(mce_timer, cpu)); |
| } |
| |
| /* |
| * Notify the user(s) about new machine check events. |
| * Can be called from interrupt context, but not from machine check/NMI |
| * context. |
| */ |
| int mce_notify_irq(void) |
| { |
| /* Not more than two messages every minute */ |
| static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2); |
| |
| if (test_and_clear_bit(0, &mce_need_notify)) { |
| mce_work_trigger(); |
| |
| if (__ratelimit(&ratelimit)) |
| pr_info(HW_ERR "Machine check events logged\n"); |
| |
| return 1; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(mce_notify_irq); |
| |
| static void __mcheck_cpu_mce_banks_init(void) |
| { |
| struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array); |
| u8 n_banks = this_cpu_read(mce_num_banks); |
| int i; |
| |
| for (i = 0; i < n_banks; i++) { |
| struct mce_bank *b = &mce_banks[i]; |
| |
| /* |
| * Init them all, __mcheck_cpu_apply_quirks() is going to apply |
| * the required vendor quirks before |
| * __mcheck_cpu_init_clear_banks() does the final bank setup. |
| */ |
| b->ctl = -1ULL; |
| b->init = true; |
| } |
| } |
| |
| /* |
| * Initialize Machine Checks for a CPU. |
| */ |
| static void __mcheck_cpu_cap_init(void) |
| { |
| u64 cap; |
| u8 b; |
| |
| rdmsrl(MSR_IA32_MCG_CAP, cap); |
| |
| b = cap & MCG_BANKCNT_MASK; |
| |
| if (b > MAX_NR_BANKS) { |
| pr_warn("CPU%d: Using only %u machine check banks out of %u\n", |
| smp_processor_id(), MAX_NR_BANKS, b); |
| b = MAX_NR_BANKS; |
| } |
| |
| this_cpu_write(mce_num_banks, b); |
| |
| __mcheck_cpu_mce_banks_init(); |
| |
| /* Use accurate RIP reporting if available. */ |
| if ((cap & MCG_EXT_P) && MCG_EXT_CNT(cap) >= 9) |
| mca_cfg.rip_msr = MSR_IA32_MCG_EIP; |
| |
| if (cap & MCG_SER_P) |
| mca_cfg.ser = 1; |
| } |
| |
| static void __mcheck_cpu_init_generic(void) |
| { |
| enum mcp_flags m_fl = 0; |
| mce_banks_t all_banks; |
| u64 cap; |
| |
| if (!mca_cfg.bootlog) |
| m_fl = MCP_DONTLOG; |
| |
| /* |
| * Log the machine checks left over from the previous reset. Log them |
| * only, do not start processing them. That will happen in mcheck_late_init() |
| * when all consumers have been registered on the notifier chain. |
| */ |
| bitmap_fill(all_banks, MAX_NR_BANKS); |
| machine_check_poll(MCP_UC | MCP_QUEUE_LOG | m_fl, &all_banks); |
| |
| cr4_set_bits(X86_CR4_MCE); |
| |
| rdmsrl(MSR_IA32_MCG_CAP, cap); |
| if (cap & MCG_CTL_P) |
| wrmsr(MSR_IA32_MCG_CTL, 0xffffffff, 0xffffffff); |
| } |
| |
| static void __mcheck_cpu_init_clear_banks(void) |
| { |
| struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array); |
| int i; |
| |
| for (i = 0; i < this_cpu_read(mce_num_banks); i++) { |
| struct mce_bank *b = &mce_banks[i]; |
| |
| if (!b->init) |
| continue; |
| wrmsrl(mca_msr_reg(i, MCA_CTL), b->ctl); |
| wrmsrl(mca_msr_reg(i, MCA_STATUS), 0); |
| } |
| } |
| |
| /* |
| * Do a final check to see if there are any unused/RAZ banks. |
| * |
| * This must be done after the banks have been initialized and any quirks have |
| * been applied. |
| * |
| * Do not call this from any user-initiated flows, e.g. CPU hotplug or sysfs. |
| * Otherwise, a user who disables a bank will not be able to re-enable it |
| * without a system reboot. |
| */ |
| static void __mcheck_cpu_check_banks(void) |
| { |
| struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array); |
| u64 msrval; |
| int i; |
| |
| for (i = 0; i < this_cpu_read(mce_num_banks); i++) { |
| struct mce_bank *b = &mce_banks[i]; |
| |
| if (!b->init) |
| continue; |
| |
| rdmsrl(mca_msr_reg(i, MCA_CTL), msrval); |
| b->init = !!msrval; |
| } |
| } |
| |
| /* Add per CPU specific workarounds here */ |
| static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c) |
| { |
| struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array); |
| struct mca_config *cfg = &mca_cfg; |
| |
| if (c->x86_vendor == X86_VENDOR_UNKNOWN) { |
| pr_info("unknown CPU type - not enabling MCE support\n"); |
| return -EOPNOTSUPP; |
| } |
| |
| /* This should be disabled by the BIOS, but isn't always */ |
| if (c->x86_vendor == X86_VENDOR_AMD) { |
| if (c->x86 == 15 && this_cpu_read(mce_num_banks) > 4) { |
| /* |
| * disable GART TBL walk error reporting, which |
| * trips off incorrectly with the IOMMU & 3ware |
| * & Cerberus: |
| */ |
| clear_bit(10, (unsigned long *)&mce_banks[4].ctl); |
| } |
| if (c->x86 < 0x11 && cfg->bootlog < 0) { |
| /* |
| * Lots of broken BIOS around that don't clear them |
| * by default and leave crap in there. Don't log: |
| */ |
| cfg->bootlog = 0; |
| } |
| /* |
| * Various K7s with broken bank 0 around. Always disable |
| * by default. |
| */ |
| if (c->x86 == 6 && this_cpu_read(mce_num_banks) > 0) |
| mce_banks[0].ctl = 0; |
| |
| /* |
| * overflow_recov is supported for F15h Models 00h-0fh |
| * even though we don't have a CPUID bit for it. |
| */ |
| if (c->x86 == 0x15 && c->x86_model <= 0xf) |
| mce_flags.overflow_recov = 1; |
| |
| if (c->x86 >= 0x17 && c->x86 <= 0x1A) |
| mce_flags.zen_ifu_quirk = 1; |
| |
| } |
| |
| if (c->x86_vendor == X86_VENDOR_INTEL) { |
| /* |
| * SDM documents that on family 6 bank 0 should not be written |
| * because it aliases to another special BIOS controlled |
| * register. |
| * But it's not aliased anymore on model 0x1a+ |
| * Don't ignore bank 0 completely because there could be a |
| * valid event later, merely don't write CTL0. |
| */ |
| |
| if (c->x86 == 6 && c->x86_model < 0x1A && this_cpu_read(mce_num_banks) > 0) |
| mce_banks[0].init = false; |
| |
| /* |
| * All newer Intel systems support MCE broadcasting. Enable |
| * synchronization with a one second timeout. |
| */ |
| if ((c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xe)) && |
| cfg->monarch_timeout < 0) |
| cfg->monarch_timeout = USEC_PER_SEC; |
| |
| /* |
| * There are also broken BIOSes on some Pentium M and |
| * earlier systems: |
| */ |
| if (c->x86 == 6 && c->x86_model <= 13 && cfg->bootlog < 0) |
| cfg->bootlog = 0; |
| |
| if (c->x86 == 6 && c->x86_model == 45) |
| mce_flags.snb_ifu_quirk = 1; |
| |
| /* |
| * Skylake, Cascacde Lake and Cooper Lake require a quirk on |
| * rep movs. |
| */ |
| if (c->x86 == 6 && c->x86_model == INTEL_FAM6_SKYLAKE_X) |
| mce_flags.skx_repmov_quirk = 1; |
| } |
| |
| if (c->x86_vendor == X86_VENDOR_ZHAOXIN) { |
| /* |
| * All newer Zhaoxin CPUs support MCE broadcasting. Enable |
| * synchronization with a one second timeout. |
| */ |
| if (c->x86 > 6 || (c->x86_model == 0x19 || c->x86_model == 0x1f)) { |
| if (cfg->monarch_timeout < 0) |
| cfg->monarch_timeout = USEC_PER_SEC; |
| } |
| } |
| |
| if (cfg->monarch_timeout < 0) |
| cfg->monarch_timeout = 0; |
| if (cfg->bootlog != 0) |
| cfg->panic_timeout = 30; |
| |
| return 0; |
| } |
| |
| static int __mcheck_cpu_ancient_init(struct cpuinfo_x86 *c) |
| { |
| if (c->x86 != 5) |
| return 0; |
| |
| switch (c->x86_vendor) { |
| case X86_VENDOR_INTEL: |
| intel_p5_mcheck_init(c); |
| mce_flags.p5 = 1; |
| return 1; |
| case X86_VENDOR_CENTAUR: |
| winchip_mcheck_init(c); |
| mce_flags.winchip = 1; |
| return 1; |
| default: |
| return 0; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Init basic CPU features needed for early decoding of MCEs. |
| */ |
| static void __mcheck_cpu_init_early(struct cpuinfo_x86 *c) |
| { |
| if (c->x86_vendor == X86_VENDOR_AMD || c->x86_vendor == X86_VENDOR_HYGON) { |
| mce_flags.overflow_recov = !!cpu_has(c, X86_FEATURE_OVERFLOW_RECOV); |
| mce_flags.succor = !!cpu_has(c, X86_FEATURE_SUCCOR); |
| mce_flags.smca = !!cpu_has(c, X86_FEATURE_SMCA); |
| mce_flags.amd_threshold = 1; |
| } |
| } |
| |
| static void mce_centaur_feature_init(struct cpuinfo_x86 *c) |
| { |
| struct mca_config *cfg = &mca_cfg; |
| |
| /* |
| * All newer Centaur CPUs support MCE broadcasting. Enable |
| * synchronization with a one second timeout. |
| */ |
| if ((c->x86 == 6 && c->x86_model == 0xf && c->x86_stepping >= 0xe) || |
| c->x86 > 6) { |
| if (cfg->monarch_timeout < 0) |
| cfg->monarch_timeout = USEC_PER_SEC; |
| } |
| } |
| |
| static void mce_zhaoxin_feature_init(struct cpuinfo_x86 *c) |
| { |
| struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array); |
| |
| /* |
| * These CPUs have MCA bank 8 which reports only one error type called |
| * SVAD (System View Address Decoder). The reporting of that error is |
| * controlled by IA32_MC8.CTL.0. |
| * |
| * If enabled, prefetching on these CPUs will cause SVAD MCE when |
| * virtual machines start and result in a system panic. Always disable |
| * bank 8 SVAD error by default. |
| */ |
| if ((c->x86 == 7 && c->x86_model == 0x1b) || |
| (c->x86_model == 0x19 || c->x86_model == 0x1f)) { |
| if (this_cpu_read(mce_num_banks) > 8) |
| mce_banks[8].ctl = 0; |
| } |
| |
| intel_init_cmci(); |
| intel_init_lmce(); |
| mce_adjust_timer = cmci_intel_adjust_timer; |
| } |
| |
| static void mce_zhaoxin_feature_clear(struct cpuinfo_x86 *c) |
| { |
| intel_clear_lmce(); |
| } |
| |
| static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c) |
| { |
| switch (c->x86_vendor) { |
| case X86_VENDOR_INTEL: |
| mce_intel_feature_init(c); |
| mce_adjust_timer = cmci_intel_adjust_timer; |
| break; |
| |
| case X86_VENDOR_AMD: { |
| mce_amd_feature_init(c); |
| break; |
| } |
| |
| case X86_VENDOR_HYGON: |
| mce_hygon_feature_init(c); |
| break; |
| |
| case X86_VENDOR_CENTAUR: |
| mce_centaur_feature_init(c); |
| break; |
| |
| case X86_VENDOR_ZHAOXIN: |
| mce_zhaoxin_feature_init(c); |
| break; |
| |
| default: |
| break; |
| } |
| } |
| |
| static void __mcheck_cpu_clear_vendor(struct cpuinfo_x86 *c) |
| { |
| switch (c->x86_vendor) { |
| case X86_VENDOR_INTEL: |
| mce_intel_feature_clear(c); |
| break; |
| |
| case X86_VENDOR_ZHAOXIN: |
| mce_zhaoxin_feature_clear(c); |
| break; |
| |
| default: |
| break; |
| } |
| } |
| |
| static void mce_start_timer(struct timer_list *t) |
| { |
| unsigned long iv = check_interval * HZ; |
| |
| if (mca_cfg.ignore_ce || !iv) |
| return; |
| |
| this_cpu_write(mce_next_interval, iv); |
| __start_timer(t, iv); |
| } |
| |
| static void __mcheck_cpu_setup_timer(void) |
| { |
| struct timer_list *t = this_cpu_ptr(&mce_timer); |
| |
| timer_setup(t, mce_timer_fn, TIMER_PINNED); |
| } |
| |
| static void __mcheck_cpu_init_timer(void) |
| { |
| struct timer_list *t = this_cpu_ptr(&mce_timer); |
| |
| timer_setup(t, mce_timer_fn, TIMER_PINNED); |
| mce_start_timer(t); |
| } |
| |
| bool filter_mce(struct mce *m) |
| { |
| if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) |
| return amd_filter_mce(m); |
| if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) |
| return intel_filter_mce(m); |
| |
| return false; |
| } |
| |
| static __always_inline void exc_machine_check_kernel(struct pt_regs *regs) |
| { |
| irqentry_state_t irq_state; |
| |
| WARN_ON_ONCE(user_mode(regs)); |
| |
| /* |
| * Only required when from kernel mode. See |
| * mce_check_crashing_cpu() for details. |
| */ |
| if (mca_cfg.initialized && mce_check_crashing_cpu()) |
| return; |
| |
| irq_state = irqentry_nmi_enter(regs); |
| |
| do_machine_check(regs); |
| |
| irqentry_nmi_exit(regs, irq_state); |
| } |
| |
| static __always_inline void exc_machine_check_user(struct pt_regs *regs) |
| { |
| irqentry_enter_from_user_mode(regs); |
| |
| do_machine_check(regs); |
| |
| irqentry_exit_to_user_mode(regs); |
| } |
| |
| #ifdef CONFIG_X86_64 |
| /* MCE hit kernel mode */ |
| DEFINE_IDTENTRY_MCE(exc_machine_check) |
| { |
| unsigned long dr7; |
| |
| dr7 = local_db_save(); |
| exc_machine_check_kernel(regs); |
| local_db_restore(dr7); |
| } |
| |
| /* The user mode variant. */ |
| DEFINE_IDTENTRY_MCE_USER(exc_machine_check) |
| { |
| unsigned long dr7; |
| |
| dr7 = local_db_save(); |
| exc_machine_check_user(regs); |
| local_db_restore(dr7); |
| } |
| #else |
| /* 32bit unified entry point */ |
| DEFINE_IDTENTRY_RAW(exc_machine_check) |
| { |
| unsigned long dr7; |
| |
| dr7 = local_db_save(); |
| if (user_mode(regs)) |
| exc_machine_check_user(regs); |
| else |
| exc_machine_check_kernel(regs); |
| local_db_restore(dr7); |
| } |
| #endif |
| |
| /* |
| * Called for each booted CPU to set up machine checks. |
| * Must be called with preempt off: |
| */ |
| void mcheck_cpu_init(struct cpuinfo_x86 *c) |
| { |
| if (mca_cfg.disabled) |
| return; |
| |
| if (__mcheck_cpu_ancient_init(c)) |
| return; |
| |
| if (!mce_available(c)) |
| return; |
| |
| __mcheck_cpu_cap_init(); |
| |
| if (__mcheck_cpu_apply_quirks(c) < 0) { |
| mca_cfg.disabled = 1; |
| return; |
| } |
| |
| if (mce_gen_pool_init()) { |
| mca_cfg.disabled = 1; |
| pr_emerg("Couldn't allocate MCE records pool!\n"); |
| return; |
| } |
| |
| mca_cfg.initialized = 1; |
| |
| __mcheck_cpu_init_early(c); |
| __mcheck_cpu_init_generic(); |
| __mcheck_cpu_init_vendor(c); |
| __mcheck_cpu_init_clear_banks(); |
| __mcheck_cpu_check_banks(); |
| __mcheck_cpu_setup_timer(); |
| } |
| |
| /* |
| * Called for each booted CPU to clear some machine checks opt-ins |
| */ |
| void mcheck_cpu_clear(struct cpuinfo_x86 *c) |
| { |
| if (mca_cfg.disabled) |
| return; |
| |
| if (!mce_available(c)) |
| return; |
| |
| /* |
| * Possibly to clear general settings generic to x86 |
| * __mcheck_cpu_clear_generic(c); |
| */ |
| __mcheck_cpu_clear_vendor(c); |
| |
| } |
| |
| static void __mce_disable_bank(void *arg) |
| { |
| int bank = *((int *)arg); |
| __clear_bit(bank, this_cpu_ptr(mce_poll_banks)); |
| cmci_disable_bank(bank); |
| } |
| |
| void mce_disable_bank(int bank) |
| { |
| if (bank >= this_cpu_read(mce_num_banks)) { |
| pr_warn(FW_BUG |
| "Ignoring request to disable invalid MCA bank %d.\n", |
| bank); |
| return; |
| } |
| set_bit(bank, mce_banks_ce_disabled); |
| on_each_cpu(__mce_disable_bank, &bank, 1); |
| } |
| |
| /* |
| * mce=off Disables machine check |
| * mce=no_cmci Disables CMCI |
| * mce=no_lmce Disables LMCE |
| * mce=dont_log_ce Clears corrected events silently, no log created for CEs. |
| * mce=print_all Print all machine check logs to console |
| * mce=ignore_ce Disables polling and CMCI, corrected events are not cleared. |
| * mce=TOLERANCELEVEL[,monarchtimeout] (number, see above) |
| * monarchtimeout is how long to wait for other CPUs on machine |
| * check, or 0 to not wait |
| * mce=bootlog Log MCEs from before booting. Disabled by default on AMD Fam10h |
| and older. |
| * mce=nobootlog Don't log MCEs from before booting. |
| * mce=bios_cmci_threshold Don't program the CMCI threshold |
| * mce=recovery force enable copy_mc_fragile() |
| */ |
| static int __init mcheck_enable(char *str) |
| { |
| struct mca_config *cfg = &mca_cfg; |
| |
| if (*str == 0) { |
| enable_p5_mce(); |
| return 1; |
| } |
| if (*str == '=') |
| str++; |
| if (!strcmp(str, "off")) |
| cfg->disabled = 1; |
| else if (!strcmp(str, "no_cmci")) |
| cfg->cmci_disabled = true; |
| else if (!strcmp(str, "no_lmce")) |
| cfg->lmce_disabled = 1; |
| else if (!strcmp(str, "dont_log_ce")) |
| cfg->dont_log_ce = true; |
| else if (!strcmp(str, "print_all")) |
| cfg->print_all = true; |
| else if (!strcmp(str, "ignore_ce")) |
| cfg->ignore_ce = true; |
| else if (!strcmp(str, "bootlog") || !strcmp(str, "nobootlog")) |
| cfg->bootlog = (str[0] == 'b'); |
| else if (!strcmp(str, "bios_cmci_threshold")) |
| cfg->bios_cmci_threshold = 1; |
| else if (!strcmp(str, "recovery")) |
| cfg->recovery = 1; |
| else if (isdigit(str[0])) |
| get_option(&str, &(cfg->monarch_timeout)); |
| else { |
| pr_info("mce argument %s ignored. Please use /sys\n", str); |
| return 0; |
| } |
| return 1; |
| } |
| __setup("mce", mcheck_enable); |
| |
| int __init mcheck_init(void) |
| { |
| mce_register_decode_chain(&early_nb); |
| mce_register_decode_chain(&mce_uc_nb); |
| mce_register_decode_chain(&mce_default_nb); |
| |
| INIT_WORK(&mce_work, mce_gen_pool_process); |
| init_irq_work(&mce_irq_work, mce_irq_work_cb); |
| |
| return 0; |
| } |
| |
| /* |
| * mce_syscore: PM support |
| */ |
| |
| /* |
| * Disable machine checks on suspend and shutdown. We can't really handle |
| * them later. |
| */ |
| static void mce_disable_error_reporting(void) |
| { |
| struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array); |
| int i; |
| |
| for (i = 0; i < this_cpu_read(mce_num_banks); i++) { |
| struct mce_bank *b = &mce_banks[i]; |
| |
| if (b->init) |
| wrmsrl(mca_msr_reg(i, MCA_CTL), 0); |
| } |
| return; |
| } |
| |
| static void vendor_disable_error_reporting(void) |
| { |
| /* |
| * Don't clear on Intel or AMD or Hygon or Zhaoxin CPUs. Some of these |
| * MSRs are socket-wide. Disabling them for just a single offlined CPU |
| * is bad, since it will inhibit reporting for all shared resources on |
| * the socket like the last level cache (LLC), the integrated memory |
| * controller (iMC), etc. |
| */ |
| if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL || |
| boot_cpu_data.x86_vendor == X86_VENDOR_HYGON || |
| boot_cpu_data.x86_vendor == X86_VENDOR_AMD || |
| boot_cpu_data.x86_vendor == X86_VENDOR_ZHAOXIN) |
| return; |
| |
| mce_disable_error_reporting(); |
| } |
| |
| static int mce_syscore_suspend(void) |
| { |
| vendor_disable_error_reporting(); |
| return 0; |
| } |
| |
| static void mce_syscore_shutdown(void) |
| { |
| vendor_disable_error_reporting(); |
| } |
| |
| /* |
| * On resume clear all MCE state. Don't want to see leftovers from the BIOS. |
| * Only one CPU is active at this time, the others get re-added later using |
| * CPU hotplug: |
| */ |
| static void mce_syscore_resume(void) |
| { |
| __mcheck_cpu_init_generic(); |
| __mcheck_cpu_init_vendor(raw_cpu_ptr(&cpu_info)); |
| __mcheck_cpu_init_clear_banks(); |
| } |
| |
| static struct syscore_ops mce_syscore_ops = { |
| .suspend = mce_syscore_suspend, |
| .shutdown = mce_syscore_shutdown, |
| .resume = mce_syscore_resume, |
| }; |
| |
| /* |
| * mce_device: Sysfs support |
| */ |
| |
| static void mce_cpu_restart(void *data) |
| { |
| if (!mce_available(raw_cpu_ptr(&cpu_info))) |
| return; |
| __mcheck_cpu_init_generic(); |
| __mcheck_cpu_init_clear_banks(); |
| __mcheck_cpu_init_timer(); |
| } |
| |
| /* Reinit MCEs after user configuration changes */ |
| static void mce_restart(void) |
| { |
| mce_timer_delete_all(); |
| on_each_cpu(mce_cpu_restart, NULL, 1); |
| mce_schedule_work(); |
| } |
| |
| /* Toggle features for corrected errors */ |
| static void mce_disable_cmci(void *data) |
| { |
| if (!mce_available(raw_cpu_ptr(&cpu_info))) |
| return; |
| cmci_clear(); |
| } |
| |
| static void mce_enable_ce(void *all) |
| { |
| if (!mce_available(raw_cpu_ptr(&cpu_info))) |
| return; |
| cmci_reenable(); |
| cmci_recheck(); |
| if (all) |
| __mcheck_cpu_init_timer(); |
| } |
| |
| static struct bus_type mce_subsys = { |
| .name = "machinecheck", |
| .dev_name = "machinecheck", |
| }; |
| |
| DEFINE_PER_CPU(struct device *, mce_device); |
| |
| static inline struct mce_bank_dev *attr_to_bank(struct device_attribute *attr) |
| { |
| return container_of(attr, struct mce_bank_dev, attr); |
| } |
| |
| static ssize_t show_bank(struct device *s, struct device_attribute *attr, |
| char *buf) |
| { |
| u8 bank = attr_to_bank(attr)->bank; |
| struct mce_bank *b; |
| |
| if (bank >= per_cpu(mce_num_banks, s->id)) |
| return -EINVAL; |
| |
| b = &per_cpu(mce_banks_array, s->id)[bank]; |
| |
| if (!b->init) |
| return -ENODEV; |
| |
| return sprintf(buf, "%llx\n", b->ctl); |
| } |
| |
| static ssize_t set_bank(struct device *s, struct device_attribute *attr, |
| const char *buf, size_t size) |
| { |
| u8 bank = attr_to_bank(attr)->bank; |
| struct mce_bank *b; |
| u64 new; |
| |
| if (kstrtou64(buf, 0, &new) < 0) |
| return -EINVAL; |
| |
| if (bank >= per_cpu(mce_num_banks, s->id)) |
| return -EINVAL; |
| |
| b = &per_cpu(mce_banks_array, s->id)[bank]; |
| |
| if (!b->init) |
| return -ENODEV; |
| |
| b->ctl = new; |
| mce_restart(); |
| |
| return size; |
| } |
| |
| static ssize_t set_ignore_ce(struct device *s, |
| struct device_attribute *attr, |
| const char *buf, size_t size) |
| { |
| u64 new; |
| |
| if (kstrtou64(buf, 0, &new) < 0) |
| return -EINVAL; |
| |
| mutex_lock(&mce_sysfs_mutex); |
| if (mca_cfg.ignore_ce ^ !!new) { |
| if (new) { |
| /* disable ce features */ |
| mce_timer_delete_all(); |
| on_each_cpu(mce_disable_cmci, NULL, 1); |
| mca_cfg.ignore_ce = true; |
| } else { |
| /* enable ce features */ |
| mca_cfg.ignore_ce = false; |
| on_each_cpu(mce_enable_ce, (void *)1, 1); |
| } |
| } |
| mutex_unlock(&mce_sysfs_mutex); |
| |
| return size; |
| } |
| |
| static ssize_t set_cmci_disabled(struct device *s, |
| struct device_attribute *attr, |
| const char *buf, size_t size) |
| { |
| u64 new; |
| |
| if (kstrtou64(buf, 0, &new) < 0) |
| return -EINVAL; |
| |
| mutex_lock(&mce_sysfs_mutex); |
| if (mca_cfg.cmci_disabled ^ !!new) { |
| if (new) { |
| /* disable cmci */ |
| on_each_cpu(mce_disable_cmci, NULL, 1); |
| mca_cfg.cmci_disabled = true; |
| } else { |
| /* enable cmci */ |
| mca_cfg.cmci_disabled = false; |
| on_each_cpu(mce_enable_ce, NULL, 1); |
| } |
| } |
| mutex_unlock(&mce_sysfs_mutex); |
| |
| return size; |
| } |
| |
| static ssize_t store_int_with_restart(struct device *s, |
| struct device_attribute *attr, |
| const char *buf, size_t size) |
| { |
| unsigned long old_check_interval = check_interval; |
| ssize_t ret = device_store_ulong(s, attr, buf, size); |
| |
| if (check_interval == old_check_interval) |
| return ret; |
| |
| mutex_lock(&mce_sysfs_mutex); |
| mce_restart(); |
| mutex_unlock(&mce_sysfs_mutex); |
| |
| return ret; |
| } |
| |
| static DEVICE_INT_ATTR(monarch_timeout, 0644, mca_cfg.monarch_timeout); |
| static DEVICE_BOOL_ATTR(dont_log_ce, 0644, mca_cfg.dont_log_ce); |
| static DEVICE_BOOL_ATTR(print_all, 0644, mca_cfg.print_all); |
| |
| static struct dev_ext_attribute dev_attr_check_interval = { |
| __ATTR(check_interval, 0644, device_show_int, store_int_with_restart), |
| &check_interval |
| }; |
| |
| static struct dev_ext_attribute dev_attr_ignore_ce = { |
| __ATTR(ignore_ce, 0644, device_show_bool, set_ignore_ce), |
| &mca_cfg.ignore_ce |
| }; |
| |
| static struct dev_ext_attribute dev_attr_cmci_disabled = { |
| __ATTR(cmci_disabled, 0644, device_show_bool, set_cmci_disabled), |
| &mca_cfg.cmci_disabled |
| }; |
| |
| static struct device_attribute *mce_device_attrs[] = { |
| &dev_attr_check_interval.attr, |
| #ifdef CONFIG_X86_MCELOG_LEGACY |
| &dev_attr_trigger, |
| #endif |
| &dev_attr_monarch_timeout.attr, |
| &dev_attr_dont_log_ce.attr, |
| &dev_attr_print_all.attr, |
| &dev_attr_ignore_ce.attr, |
| &dev_attr_cmci_disabled.attr, |
| NULL |
| }; |
| |
| static cpumask_var_t mce_device_initialized; |
| |
| static void mce_device_release(struct device *dev) |
| { |
| kfree(dev); |
| } |
| |
| /* Per CPU device init. All of the CPUs still share the same bank device: */ |
| static int mce_device_create(unsigned int cpu) |
| { |
| struct device *dev; |
| int err; |
| int i, j; |
| |
| if (!mce_available(&boot_cpu_data)) |
| return -EIO; |
| |
| dev = per_cpu(mce_device, cpu); |
| if (dev) |
| return 0; |
| |
| dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
| if (!dev) |
| return -ENOMEM; |
| dev->id = cpu; |
| dev->bus = &mce_subsys; |
| dev->release = &mce_device_release; |
| |
| err = device_register(dev); |
| if (err) { |
| put_device(dev); |
| return err; |
| } |
| |
| for (i = 0; mce_device_attrs[i]; i++) { |
| err = device_create_file(dev, mce_device_attrs[i]); |
| if (err) |
| goto error; |
| } |
| for (j = 0; j < per_cpu(mce_num_banks, cpu); j++) { |
| err = device_create_file(dev, &mce_bank_devs[j].attr); |
| if (err) |
| goto error2; |
| } |
| cpumask_set_cpu(cpu, mce_device_initialized); |
| per_cpu(mce_device, cpu) = dev; |
| |
| return 0; |
| error2: |
| while (--j >= 0) |
| device_remove_file(dev, &mce_bank_devs[j].attr); |
| error: |
| while (--i >= 0) |
| device_remove_file(dev, mce_device_attrs[i]); |
| |
| device_unregister(dev); |
| |
| return err; |
| } |
| |
| static void mce_device_remove(unsigned int cpu) |
| { |
| struct device *dev = per_cpu(mce_device, cpu); |
| int i; |
| |
| if (!cpumask_test_cpu(cpu, mce_device_initialized)) |
| return; |
| |
| for (i = 0; mce_device_attrs[i]; i++) |
| device_remove_file(dev, mce_device_attrs[i]); |
| |
| for (i = 0; i < per_cpu(mce_num_banks, cpu); i++) |
| device_remove_file(dev, &mce_bank_devs[i].attr); |
| |
| device_unregister(dev); |
| cpumask_clear_cpu(cpu, mce_device_initialized); |
| per_cpu(mce_device, cpu) = NULL; |
| } |
| |
| /* Make sure there are no machine checks on offlined CPUs. */ |
| static void mce_disable_cpu(void) |
| { |
| if (!mce_available(raw_cpu_ptr(&cpu_info))) |
| return; |
| |
| if (!cpuhp_tasks_frozen) |
| cmci_clear(); |
| |
| vendor_disable_error_reporting(); |
| } |
| |
| static void mce_reenable_cpu(void) |
| { |
| struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array); |
| int i; |
| |
| if (!mce_available(raw_cpu_ptr(&cpu_info))) |
| return; |
| |
| if (!cpuhp_tasks_frozen) |
| cmci_reenable(); |
| for (i = 0; i < this_cpu_read(mce_num_banks); i++) { |
| struct mce_bank *b = &mce_banks[i]; |
| |
| if (b->init) |
| wrmsrl(mca_msr_reg(i, MCA_CTL), b->ctl); |
| } |
| } |
| |
| static int mce_cpu_dead(unsigned int cpu) |
| { |
| mce_intel_hcpu_update(cpu); |
| |
| /* intentionally ignoring frozen here */ |
| if (!cpuhp_tasks_frozen) |
| cmci_rediscover(); |
| return 0; |
| } |
| |
| static int mce_cpu_online(unsigned int cpu) |
| { |
| struct timer_list *t = this_cpu_ptr(&mce_timer); |
| int ret; |
| |
| mce_device_create(cpu); |
| |
| ret = mce_threshold_create_device(cpu); |
| if (ret) { |
| mce_device_remove(cpu); |
| return ret; |
| } |
| mce_reenable_cpu(); |
| mce_start_timer(t); |
| return 0; |
| } |
| |
| static int mce_cpu_pre_down(unsigned int cpu) |
| { |
| struct timer_list *t = this_cpu_ptr(&mce_timer); |
| |
| mce_disable_cpu(); |
| del_timer_sync(t); |
| mce_threshold_remove_device(cpu); |
| mce_device_remove(cpu); |
| return 0; |
| } |
| |
| static __init void mce_init_banks(void) |
| { |
| int i; |
| |
| for (i = 0; i < MAX_NR_BANKS; i++) { |
| struct mce_bank_dev *b = &mce_bank_devs[i]; |
| struct device_attribute *a = &b->attr; |
| |
| b->bank = i; |
| |
| sysfs_attr_init(&a->attr); |
| a->attr.name = b->attrname; |
| snprintf(b->attrname, ATTR_LEN, "bank%d", i); |
| |
| a->attr.mode = 0644; |
| a->show = show_bank; |
| a->store = set_bank; |
| } |
| } |
| |
| /* |
| * When running on XEN, this initcall is ordered against the XEN mcelog |
| * initcall: |
| * |
| * device_initcall(xen_late_init_mcelog); |
| * device_initcall_sync(mcheck_init_device); |
| */ |
| static __init int mcheck_init_device(void) |
| { |
| int err; |
| |
| /* |
| * Check if we have a spare virtual bit. This will only become |
| * a problem if/when we move beyond 5-level page tables. |
| */ |
| MAYBE_BUILD_BUG_ON(__VIRTUAL_MASK_SHIFT >= 63); |
| |
| if (!mce_available(&boot_cpu_data)) { |
| err = -EIO; |
| goto err_out; |
| } |
| |
| if (!zalloc_cpumask_var(&mce_device_initialized, GFP_KERNEL)) { |
| err = -ENOMEM; |
| goto err_out; |
| } |
| |
| mce_init_banks(); |
| |
| err = subsys_system_register(&mce_subsys, NULL); |
| if (err) |
| goto err_out_mem; |
| |
| err = cpuhp_setup_state(CPUHP_X86_MCE_DEAD, "x86/mce:dead", NULL, |
| mce_cpu_dead); |
| if (err) |
| goto err_out_mem; |
| |
| /* |
| * Invokes mce_cpu_online() on all CPUs which are online when |
| * the state is installed. |
| */ |
| err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/mce:online", |
| mce_cpu_online, mce_cpu_pre_down); |
| if (err < 0) |
| goto err_out_online; |
| |
| register_syscore_ops(&mce_syscore_ops); |
| |
| return 0; |
| |
| err_out_online: |
| cpuhp_remove_state(CPUHP_X86_MCE_DEAD); |
| |
| err_out_mem: |
| free_cpumask_var(mce_device_initialized); |
| |
| err_out: |
| pr_err("Unable to init MCE device (rc: %d)\n", err); |
| |
| return err; |
| } |
| device_initcall_sync(mcheck_init_device); |
| |
| /* |
| * Old style boot options parsing. Only for compatibility. |
| */ |
| static int __init mcheck_disable(char *str) |
| { |
| mca_cfg.disabled = 1; |
| return 1; |
| } |
| __setup("nomce", mcheck_disable); |
| |
| #ifdef CONFIG_DEBUG_FS |
| struct dentry *mce_get_debugfs_dir(void) |
| { |
| static struct dentry *dmce; |
| |
| if (!dmce) |
| dmce = debugfs_create_dir("mce", NULL); |
| |
| return dmce; |
| } |
| |
| static void mce_reset(void) |
| { |
| atomic_set(&mce_fake_panicked, 0); |
| atomic_set(&mce_executing, 0); |
| atomic_set(&mce_callin, 0); |
| atomic_set(&global_nwo, 0); |
| cpumask_setall(&mce_missing_cpus); |
| } |
| |
| static int fake_panic_get(void *data, u64 *val) |
| { |
| *val = fake_panic; |
| return 0; |
| } |
| |
| static int fake_panic_set(void *data, u64 val) |
| { |
| mce_reset(); |
| fake_panic = val; |
| return 0; |
| } |
| |
| DEFINE_DEBUGFS_ATTRIBUTE(fake_panic_fops, fake_panic_get, fake_panic_set, |
| "%llu\n"); |
| |
| static void __init mcheck_debugfs_init(void) |
| { |
| struct dentry *dmce; |
| |
| dmce = mce_get_debugfs_dir(); |
| debugfs_create_file_unsafe("fake_panic", 0444, dmce, NULL, |
| &fake_panic_fops); |
| } |
| #else |
| static void __init mcheck_debugfs_init(void) { } |
| #endif |
| |
| static int __init mcheck_late_init(void) |
| { |
| if (mca_cfg.recovery) |
| enable_copy_mc_fragile(); |
| |
| mcheck_debugfs_init(); |
| |
| /* |
| * Flush out everything that has been logged during early boot, now that |
| * everything has been initialized (workqueues, decoders, ...). |
| */ |
| mce_schedule_work(); |
| |
| return 0; |
| } |
| late_initcall(mcheck_late_init); |