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-rw-r--r--arch/x86/Kconfig8
-rw-r--r--arch/x86/include/asm/mce.h3
-rw-r--r--arch/x86/kernel/cpu/mcheck/Makefile1
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce-inject.c126
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce.c39
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(&regs, 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(&regs, 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,
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