From 5b7e88edc6193f36941bccbfd5ed9ed5fe27d2e1 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Fri, 31 Jul 2009 09:41:40 +0800 Subject: [PATCH 1/8] x86, mce: Support specifying context for software mce injection The cpu context is specified via the new mce.inject_flags fields. This allows more realistic machine check testing in different situations. "RANDOM" context is implemented via NMI broadcasting to add randomization to testing. AK: Fix NMI broadcasting check. Fix 32-bit building. Some race fixes. Move to module. Various changes ChangeLog: v3: - Re-based on latest x86-tip.git/mce4 - Fix 32-bit building v2: - Re-base on latest x86-tip.git/mce3 Signed-off-by: Huang Ying Signed-off-by: Andi Kleen Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/mce.h | 11 +- arch/x86/kernel/cpu/mcheck/mce-inject.c | 156 +++++++++++++++++++++++++------- 2 files changed, 135 insertions(+), 32 deletions(-) --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -38,6 +38,13 @@ #define MCM_ADDR_MEM 3 /* memory address */ #define MCM_ADDR_GENERIC 7 /* generic */ +#define MCJ_CTX_MASK 3 +#define MCJ_CTX(flags) ((flags) & MCJ_CTX_MASK) +#define MCJ_CTX_RANDOM 0 /* inject context: random */ +#define MCJ_CTX_PROCESS 1 /* inject context: process */ +#define MCJ_CTX_IRQ 2 /* inject context: IRQ */ +#define MCJ_NMI_BROADCAST 4 /* do NMI broadcasting */ + /* Fields are zero when not available */ struct mce { __u64 status; @@ -48,8 +55,8 @@ struct mce { __u64 tsc; /* cpu time stamp counter */ __u64 time; /* wall time_t when error was detected */ __u8 cpuvendor; /* cpu vendor as encoded in system.h */ - __u8 pad1; - __u16 pad2; + __u8 inject_flags; /* software inject flags */ + __u16 pad; __u32 cpuid; /* CPUID 1 EAX */ __u8 cs; /* code segment */ __u8 bank; /* machine check bank */ --- a/arch/x86/kernel/cpu/mcheck/mce-inject.c +++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c @@ -18,7 +18,12 @@ #include #include #include +#include +#include +#include +#include #include +#include /* Update fake mce registers on current CPU. */ static void inject_mce(struct mce *m) @@ -39,44 +44,141 @@ static void inject_mce(struct mce *m) i->finished = 1; } -struct delayed_mce { - struct timer_list timer; - struct mce m; +static void raise_corrected(struct mce *m) +{ + unsigned long flags; + mce_banks_t b; + + memset(&b, 0xff, sizeof(mce_banks_t)); + local_irq_save(flags); + machine_check_poll(0, &b); + local_irq_restore(flags); + m->finished = 0; +} + +static void raise_uncorrected(struct mce *m, struct pt_regs *pregs) +{ + struct pt_regs regs; + unsigned long flags; + + if (!pregs) { + memset(®s, 0, sizeof(struct pt_regs)); + regs.ip = m->ip; + regs.cs = m->cs; + pregs = ®s; + } + /* in mcheck exeception handler, irq will be disabled */ + local_irq_save(flags); + do_machine_check(pregs, 0); + local_irq_restore(flags); + m->finished = 0; +} + +static cpumask_t mce_inject_cpumask; + +static int mce_raise_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + struct die_args *args = (struct die_args *)data; + int cpu = smp_processor_id(); + struct mce *m = &__get_cpu_var(injectm); + if (val != DIE_NMI_IPI || !cpu_isset(cpu, mce_inject_cpumask)) + return NOTIFY_DONE; + cpu_clear(cpu, mce_inject_cpumask); + if (m->status & MCI_STATUS_UC) + raise_uncorrected(m, args->regs); + else if (m->status) + raise_corrected(m); + return NOTIFY_STOP; +} + +static struct notifier_block mce_raise_nb = { + .notifier_call = mce_raise_notify, + .priority = 1000, }; /* Inject mce on current CPU */ -static void raise_mce(unsigned long data) +static int raise_local(struct mce *m) { - struct delayed_mce *dm = (struct delayed_mce *)data; - struct mce *m = &dm->m; + int context = MCJ_CTX(m->inject_flags); + int ret = 0; int cpu = m->extcpu; - inject_mce(m); if (m->status & MCI_STATUS_UC) { - struct pt_regs regs; - memset(®s, 0, sizeof(struct pt_regs)); - regs.ip = m->ip; - regs.cs = m->cs; printk(KERN_INFO "Triggering MCE exception on CPU %d\n", cpu); - do_machine_check(®s, 0); + switch (context) { + case MCJ_CTX_IRQ: + /* + * Could do more to fake interrupts like + * calling irq_enter, but the necessary + * machinery isn't exported currently. + */ + /*FALL THROUGH*/ + case MCJ_CTX_PROCESS: + raise_uncorrected(m, NULL); + break; + default: + printk(KERN_INFO "Invalid MCE context\n"); + ret = -EINVAL; + } printk(KERN_INFO "MCE exception done on CPU %d\n", cpu); - } else { - mce_banks_t b; - memset(&b, 0xff, sizeof(mce_banks_t)); + } else if (m->status) { printk(KERN_INFO "Starting machine check poll CPU %d\n", cpu); - machine_check_poll(0, &b); + raise_corrected(m); mce_notify_irq(); - printk(KERN_INFO "Finished machine check poll on CPU %d\n", - cpu); - } - kfree(dm); + printk(KERN_INFO "Machine check poll done on CPU %d\n", cpu); + } else + m->finished = 0; + + return ret; +} + +static void raise_mce(struct mce *m) +{ + int context = MCJ_CTX(m->inject_flags); + + inject_mce(m); + + if (context == MCJ_CTX_RANDOM) + return; + +#ifdef CONFIG_X86_LOCAL_APIC + if (m->inject_flags & MCJ_NMI_BROADCAST) { + unsigned long start; + int cpu; + get_online_cpus(); + mce_inject_cpumask = cpu_online_map; + cpu_clear(get_cpu(), mce_inject_cpumask); + for_each_online_cpu(cpu) { + struct mce *mcpu = &per_cpu(injectm, cpu); + if (!mcpu->finished || + MCJ_CTX(mcpu->inject_flags) != MCJ_CTX_RANDOM) + cpu_clear(cpu, mce_inject_cpumask); + } + if (!cpus_empty(mce_inject_cpumask)) + apic->send_IPI_mask(&mce_inject_cpumask, NMI_VECTOR); + start = jiffies; + while (!cpus_empty(mce_inject_cpumask)) { + if (!time_before(jiffies, start + 2*HZ)) { + printk(KERN_ERR + "Timeout waiting for mce inject NMI %lx\n", + *cpus_addr(mce_inject_cpumask)); + break; + } + cpu_relax(); + } + raise_local(m); + put_cpu(); + put_online_cpus(); + } else +#endif + raise_local(m); } /* Error injection interface */ static ssize_t mce_write(struct file *filp, const char __user *ubuf, size_t usize, loff_t *off) { - struct delayed_mce *dm; struct mce m; if (!capable(CAP_SYS_ADMIN)) @@ -96,19 +198,12 @@ static ssize_t mce_write(struct file *fi if (m.extcpu >= num_possible_cpus() || !cpu_online(m.extcpu)) return -EINVAL; - dm = kmalloc(sizeof(struct delayed_mce), GFP_KERNEL); - if (!dm) - return -ENOMEM; - /* * Need to give user space some time to set everything up, * so do it a jiffie or two later everywhere. - * Should we use a hrtimer here for better synchronization? */ - memcpy(&dm->m, &m, sizeof(struct mce)); - setup_timer(&dm->timer, raise_mce, (unsigned long)dm); - dm->timer.expires = jiffies + 2; - add_timer_on(&dm->timer, m.extcpu); + schedule_timeout(2); + raise_mce(&m); return usize; } @@ -116,6 +211,7 @@ static int inject_init(void) { printk(KERN_INFO "Machine check injector initialized\n"); mce_chrdev_ops.write = mce_write; + register_die_notifier(&mce_raise_nb); return 0; }