diff options
| -rw-r--r-- | arch/x86/Kconfig | 8 | ||||
| -rw-r--r-- | arch/x86/include/asm/mce.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce-inject.c | 126 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce.c | 39 |
5 files changed, 176 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index a148e7a..e25b635 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -835,6 +835,14 @@ config X86_MCE_THRESHOLD bool default y +config X86_MCE_INJECT + depends on X86_NEW_MCE + tristate "Machine check injector support" + ---help--- + Provide support for injecting machine checks for testing purposes. + If you don't know what a machine check is and you don't do kernel + QA it is safe to say n. + config X86_MCE_NONFATAL tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4" depends on X86_OLD_MCE diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index c3c7ee7..e7d2372 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -141,6 +141,9 @@ extern void machine_check_poll(enum mcp_flags flags, mce_banks_t *b); extern int mce_notify_user(void); +DECLARE_PER_CPU(struct mce, injectm); +extern struct file_operations mce_chrdev_ops; + #ifdef CONFIG_X86_MCE extern void mcheck_init(struct cpuinfo_x86 *c); #else diff --git a/arch/x86/kernel/cpu/mcheck/Makefile b/arch/x86/kernel/cpu/mcheck/Makefile index 5f8b094..60ee182 100644 --- a/arch/x86/kernel/cpu/mcheck/Makefile +++ b/arch/x86/kernel/cpu/mcheck/Makefile @@ -7,3 +7,4 @@ obj-$(CONFIG_X86_MCE_INTEL) += mce_intel_64.o mce_intel.o obj-$(CONFIG_X86_MCE_AMD) += mce_amd_64.o obj-$(CONFIG_X86_MCE_NONFATAL) += non-fatal.o obj-$(CONFIG_X86_MCE_THRESHOLD) += threshold.o +obj-$(CONFIG_X86_MCE_INJECT) += mce-inject.o diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c new file mode 100644 index 0000000..58afac4 --- /dev/null +++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c @@ -0,0 +1,126 @@ +/* + * Machine check injection support. + * Copyright 2008 Intel Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + * + * Authors: + * Andi Kleen + * Ying Huang + */ +#include <linux/module.h> +#include <linux/timer.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/fs.h> +#include <linux/smp.h> +#include <asm/uaccess.h> +#include <asm/mce.h> + +/* Update fake mce registers on current CPU. */ +static void inject_mce(struct mce *m) +{ + struct mce *i = &per_cpu(injectm, m->cpu); + + /* Make sure noone reads partially written injectm */ + i->finished = 0; + mb(); + m->finished = 0; + /* First set the fields after finished */ + i->cpu = m->cpu; + mb(); + /* Now write record in order, finished last (except above) */ + memcpy(i, m, sizeof(struct mce)); + /* Finally activate it */ + mb(); + i->finished = 1; +} + +struct delayed_mce { + struct timer_list timer; + struct mce m; +}; + +/* Inject mce on current CPU */ +static void raise_mce(unsigned long data) +{ + struct delayed_mce *dm = (struct delayed_mce *)data; + struct mce *m = &dm->m; + int cpu = m->cpu; + + 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); + printk(KERN_INFO "MCE exception done on CPU %d\n", cpu); + } else { + mce_banks_t b; + memset(&b, 0xff, sizeof(mce_banks_t)); + printk(KERN_INFO "Starting machine check poll CPU %d\n", cpu); + machine_check_poll(0, &b); + mce_notify_user(); + printk(KERN_INFO "Finished machine check poll on CPU %d\n", + cpu); + } + kfree(dm); +} + +/* 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)) + return -EPERM; + /* + * There are some cases where real MSR reads could slip + * through. + */ + if (!boot_cpu_has(X86_FEATURE_MCE) || !boot_cpu_has(X86_FEATURE_MCA)) + return -EIO; + + if ((unsigned long)usize > sizeof(struct mce)) + usize = sizeof(struct mce); + if (copy_from_user(&m, ubuf, usize)) + return -EFAULT; + + if (m.cpu >= NR_CPUS || !cpu_online(m.cpu)) + 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.cpu); + return usize; +} + +static int inject_init(void) +{ + printk(KERN_INFO "Machine check injector initialized\n"); + mce_chrdev_ops.write = mce_write; + return 0; +} + +module_init(inject_init); +/* Cannot tolerate unloading currently because we cannot + * guarantee all openers of mce_chrdev will get a reference to us. + */ +MODULE_LICENSE("GPL"); diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index e755c95..fe216bd 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -98,6 +98,9 @@ void mce_setup(struct mce *m) rdtscll(m->tsc); } +DEFINE_PER_CPU(struct mce, injectm); +EXPORT_PER_CPU_SYMBOL_GPL(injectm); + /* * Lockless MCE logging infrastructure. * This avoids deadlocks on printk locks without having to break locks. Also @@ -194,16 +197,46 @@ static void mce_panic(char *msg, struct mce *backup, u64 start) panic(msg); } +/* Support code for software error injection */ + +static int msr_to_offset(u32 msr) +{ + unsigned bank = __get_cpu_var(injectm.bank); + if (msr == rip_msr) + return offsetof(struct mce, ip); + if (msr == MSR_IA32_MC0_STATUS + bank*4) + return offsetof(struct mce, status); + if (msr == MSR_IA32_MC0_ADDR + bank*4) + return offsetof(struct mce, addr); + if (msr == MSR_IA32_MC0_MISC + bank*4) + return offsetof(struct mce, misc); + if (msr == MSR_IA32_MCG_STATUS) + return offsetof(struct mce, mcgstatus); + return -1; +} + /* MSR access wrappers used for error injection */ static u64 mce_rdmsrl(u32 msr) { u64 v; + if (__get_cpu_var(injectm).finished) { + int offset = msr_to_offset(msr); + if (offset < 0) + return 0; + return *(u64 *)((char *)&__get_cpu_var(injectm) + offset); + } rdmsrl(msr, v); return v; } static void mce_wrmsrl(u32 msr, u64 v) { + if (__get_cpu_var(injectm).finished) { + int offset = msr_to_offset(msr); + if (offset >= 0) + *(u64 *)((char *)&__get_cpu_var(injectm) + offset) = v; + return; + } wrmsrl(msr, v); } @@ -296,6 +329,7 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b) * exceptions. */ } +EXPORT_SYMBOL_GPL(machine_check_poll); /* * The actual machine check handler. This only handles real @@ -468,6 +502,7 @@ void do_machine_check(struct pt_regs *regs, long error_code) out2: atomic_dec(&mce_entry); } +EXPORT_SYMBOL_GPL(do_machine_check); #ifdef CONFIG_X86_MCE_INTEL /*** @@ -568,6 +603,7 @@ int mce_notify_user(void) } return 0; } +EXPORT_SYMBOL_GPL(mce_notify_user); /* * Initialize Machine Checks for a CPU. @@ -904,13 +940,14 @@ static long mce_ioctl(struct file *f, unsigned int cmd, unsigned long arg) } } -static const struct file_operations mce_chrdev_ops = { +struct file_operations mce_chrdev_ops = { .open = mce_open, .release = mce_release, .read = mce_read, .poll = mce_poll, .unlocked_ioctl = mce_ioctl, }; +EXPORT_SYMBOL_GPL(mce_chrdev_ops); static struct miscdevice mce_log_device = { MISC_MCELOG_MINOR, |
