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@@ -0,0 +1,126 @@
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+/*
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+ * Machine check injection support.
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+ * Copyright 2008 Intel Corporation.
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+ *
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+ * This program is free software; you can redistribute it and/or
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+ * modify it under the terms of the GNU General Public License
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+ * as published by the Free Software Foundation; version 2
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+ * of the License.
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+ *
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+ * Authors:
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+ * Andi Kleen
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+ * Ying Huang
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+ */
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+#include <linux/module.h>
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+#include <linux/timer.h>
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+#include <linux/kernel.h>
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+#include <linux/string.h>
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+#include <linux/fs.h>
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+#include <linux/smp.h>
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+#include <asm/uaccess.h>
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+#include <asm/mce.h>
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+
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+/* Update fake mce registers on current CPU. */
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+static void inject_mce(struct mce *m)
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+{
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+ struct mce *i = &per_cpu(injectm, m->cpu);
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+
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+ /* Make sure noone reads partially written injectm */
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+ i->finished = 0;
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+ mb();
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+ m->finished = 0;
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+ /* First set the fields after finished */
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+ i->cpu = m->cpu;
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+ mb();
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+ /* Now write record in order, finished last (except above) */
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+ memcpy(i, m, sizeof(struct mce));
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+ /* Finally activate it */
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+ mb();
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+ i->finished = 1;
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+}
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+
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+struct delayed_mce {
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+ struct timer_list timer;
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+ struct mce m;
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+};
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+
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+/* Inject mce on current CPU */
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+static void raise_mce(unsigned long data)
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+{
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+ struct delayed_mce *dm = (struct delayed_mce *)data;
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+ struct mce *m = &dm->m;
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+ int cpu = m->cpu;
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+
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+ inject_mce(m);
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+ if (m->status & MCI_STATUS_UC) {
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+ struct pt_regs regs;
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+ memset(®s, 0, sizeof(struct pt_regs));
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+ regs.ip = m->ip;
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+ regs.cs = m->cs;
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+ printk(KERN_INFO "Triggering MCE exception on CPU %d\n", cpu);
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+ do_machine_check(®s, 0);
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+ printk(KERN_INFO "MCE exception done on CPU %d\n", cpu);
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+ } else {
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+ mce_banks_t b;
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+ memset(&b, 0xff, sizeof(mce_banks_t));
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+ printk(KERN_INFO "Starting machine check poll CPU %d\n", cpu);
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+ machine_check_poll(0, &b);
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+ mce_notify_user();
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+ printk(KERN_INFO "Finished machine check poll on CPU %d\n",
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+ cpu);
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+ }
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+ kfree(dm);
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+}
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+
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+/* Error injection interface */
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+static ssize_t mce_write(struct file *filp, const char __user *ubuf,
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+ size_t usize, loff_t *off)
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+{
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+ struct delayed_mce *dm;
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+ struct mce m;
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+
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+ if (!capable(CAP_SYS_ADMIN))
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+ return -EPERM;
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+ /*
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+ * There are some cases where real MSR reads could slip
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+ * through.
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+ */
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+ if (!boot_cpu_has(X86_FEATURE_MCE) || !boot_cpu_has(X86_FEATURE_MCA))
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+ return -EIO;
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+
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+ if ((unsigned long)usize > sizeof(struct mce))
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+ usize = sizeof(struct mce);
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+ if (copy_from_user(&m, ubuf, usize))
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+ return -EFAULT;
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+
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+ if (m.cpu >= NR_CPUS || !cpu_online(m.cpu))
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+ return -EINVAL;
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+
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+ dm = kmalloc(sizeof(struct delayed_mce), GFP_KERNEL);
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+ if (!dm)
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+ return -ENOMEM;
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+
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+ /*
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+ * Need to give user space some time to set everything up,
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+ * so do it a jiffie or two later everywhere.
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+ * Should we use a hrtimer here for better synchronization?
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+ */
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+ memcpy(&dm->m, &m, sizeof(struct mce));
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+ setup_timer(&dm->timer, raise_mce, (unsigned long)dm);
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+ dm->timer.expires = jiffies + 2;
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+ add_timer_on(&dm->timer, m.cpu);
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+ return usize;
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+}
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+
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+static int inject_init(void)
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+{
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+ printk(KERN_INFO "Machine check injector initialized\n");
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+ mce_chrdev_ops.write = mce_write;
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+ return 0;
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+}
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+
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+module_init(inject_init);
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+/* Cannot tolerate unloading currently because we cannot
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+ * guarantee all openers of mce_chrdev will get a reference to us.
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+ */
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+MODULE_LICENSE("GPL");
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