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Diffstat (limited to 'arch/x86/kernel/cpu/mcheck/dev-mcelog.c')
-rw-r--r--arch/x86/kernel/cpu/mcheck/dev-mcelog.c430
1 files changed, 0 insertions, 430 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/dev-mcelog.c b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c
deleted file mode 100644
index 10cec43aac38..000000000000
--- a/arch/x86/kernel/cpu/mcheck/dev-mcelog.c
+++ /dev/null
@@ -1,430 +0,0 @@
-/*
- * /dev/mcelog driver
- *
- * 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
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/miscdevice.h>
-#include <linux/slab.h>
-#include <linux/kmod.h>
-#include <linux/poll.h>
-
-#include "mce-internal.h"
-
-static BLOCKING_NOTIFIER_HEAD(mce_injector_chain);
-
-static DEFINE_MUTEX(mce_chrdev_read_mutex);
-
-static char mce_helper[128];
-static char *mce_helper_argv[2] = { mce_helper, NULL };
-
-#define mce_log_get_idx_check(p) \
-({ \
- RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \
- !lockdep_is_held(&mce_chrdev_read_mutex), \
- "suspicious mce_log_get_idx_check() usage"); \
- smp_load_acquire(&(p)); \
-})
-
-/*
- * Lockless MCE logging infrastructure.
- * This avoids deadlocks on printk locks without having to break locks. Also
- * separate MCEs from kernel messages to avoid bogus bug reports.
- */
-
-static struct mce_log_buffer mcelog = {
- .signature = MCE_LOG_SIGNATURE,
- .len = MCE_LOG_LEN,
- .recordlen = sizeof(struct mce),
-};
-
-static DECLARE_WAIT_QUEUE_HEAD(mce_chrdev_wait);
-
-/* User mode helper program triggered by machine check event */
-extern char mce_helper[128];
-
-static int dev_mce_log(struct notifier_block *nb, unsigned long val,
- void *data)
-{
- struct mce *mce = (struct mce *)data;
- unsigned int next, entry;
-
- wmb();
- for (;;) {
- entry = mce_log_get_idx_check(mcelog.next);
- for (;;) {
-
- /*
- * When the buffer fills up discard new entries.
- * Assume that the earlier errors are the more
- * interesting ones:
- */
- if (entry >= MCE_LOG_LEN) {
- set_bit(MCE_OVERFLOW,
- (unsigned long *)&mcelog.flags);
- return NOTIFY_OK;
- }
- /* Old left over entry. Skip: */
- if (mcelog.entry[entry].finished) {
- entry++;
- continue;
- }
- break;
- }
- smp_rmb();
- next = entry + 1;
- if (cmpxchg(&mcelog.next, entry, next) == entry)
- break;
- }
- memcpy(mcelog.entry + entry, mce, sizeof(struct mce));
- wmb();
- mcelog.entry[entry].finished = 1;
- wmb();
-
- /* wake processes polling /dev/mcelog */
- wake_up_interruptible(&mce_chrdev_wait);
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block dev_mcelog_nb = {
- .notifier_call = dev_mce_log,
- .priority = MCE_PRIO_MCELOG,
-};
-
-static void mce_do_trigger(struct work_struct *work)
-{
- call_usermodehelper(mce_helper, mce_helper_argv, NULL, UMH_NO_WAIT);
-}
-
-static DECLARE_WORK(mce_trigger_work, mce_do_trigger);
-
-
-void mce_work_trigger(void)
-{
- if (mce_helper[0])
- schedule_work(&mce_trigger_work);
-}
-
-static ssize_t
-show_trigger(struct device *s, struct device_attribute *attr, char *buf)
-{
- strcpy(buf, mce_helper);
- strcat(buf, "\n");
- return strlen(mce_helper) + 1;
-}
-
-static ssize_t set_trigger(struct device *s, struct device_attribute *attr,
- const char *buf, size_t siz)
-{
- char *p;
-
- strncpy(mce_helper, buf, sizeof(mce_helper));
- mce_helper[sizeof(mce_helper)-1] = 0;
- p = strchr(mce_helper, '\n');
-
- if (p)
- *p = 0;
-
- return strlen(mce_helper) + !!p;
-}
-
-DEVICE_ATTR(trigger, 0644, show_trigger, set_trigger);
-
-/*
- * mce_chrdev: Character device /dev/mcelog to read and clear the MCE log.
- */
-
-static DEFINE_SPINLOCK(mce_chrdev_state_lock);
-static int mce_chrdev_open_count; /* #times opened */
-static int mce_chrdev_open_exclu; /* already open exclusive? */
-
-static int mce_chrdev_open(struct inode *inode, struct file *file)
-{
- spin_lock(&mce_chrdev_state_lock);
-
- if (mce_chrdev_open_exclu ||
- (mce_chrdev_open_count && (file->f_flags & O_EXCL))) {
- spin_unlock(&mce_chrdev_state_lock);
-
- return -EBUSY;
- }
-
- if (file->f_flags & O_EXCL)
- mce_chrdev_open_exclu = 1;
- mce_chrdev_open_count++;
-
- spin_unlock(&mce_chrdev_state_lock);
-
- return nonseekable_open(inode, file);
-}
-
-static int mce_chrdev_release(struct inode *inode, struct file *file)
-{
- spin_lock(&mce_chrdev_state_lock);
-
- mce_chrdev_open_count--;
- mce_chrdev_open_exclu = 0;
-
- spin_unlock(&mce_chrdev_state_lock);
-
- return 0;
-}
-
-static void collect_tscs(void *data)
-{
- unsigned long *cpu_tsc = (unsigned long *)data;
-
- cpu_tsc[smp_processor_id()] = rdtsc();
-}
-
-static int mce_apei_read_done;
-
-/* Collect MCE record of previous boot in persistent storage via APEI ERST. */
-static int __mce_read_apei(char __user **ubuf, size_t usize)
-{
- int rc;
- u64 record_id;
- struct mce m;
-
- if (usize < sizeof(struct mce))
- return -EINVAL;
-
- rc = apei_read_mce(&m, &record_id);
- /* Error or no more MCE record */
- if (rc <= 0) {
- mce_apei_read_done = 1;
- /*
- * When ERST is disabled, mce_chrdev_read() should return
- * "no record" instead of "no device."
- */
- if (rc == -ENODEV)
- return 0;
- return rc;
- }
- rc = -EFAULT;
- if (copy_to_user(*ubuf, &m, sizeof(struct mce)))
- return rc;
- /*
- * In fact, we should have cleared the record after that has
- * been flushed to the disk or sent to network in
- * /sbin/mcelog, but we have no interface to support that now,
- * so just clear it to avoid duplication.
- */
- rc = apei_clear_mce(record_id);
- if (rc) {
- mce_apei_read_done = 1;
- return rc;
- }
- *ubuf += sizeof(struct mce);
-
- return 0;
-}
-
-static ssize_t mce_chrdev_read(struct file *filp, char __user *ubuf,
- size_t usize, loff_t *off)
-{
- char __user *buf = ubuf;
- unsigned long *cpu_tsc;
- unsigned prev, next;
- int i, err;
-
- cpu_tsc = kmalloc(nr_cpu_ids * sizeof(long), GFP_KERNEL);
- if (!cpu_tsc)
- return -ENOMEM;
-
- mutex_lock(&mce_chrdev_read_mutex);
-
- if (!mce_apei_read_done) {
- err = __mce_read_apei(&buf, usize);
- if (err || buf != ubuf)
- goto out;
- }
-
- next = mce_log_get_idx_check(mcelog.next);
-
- /* Only supports full reads right now */
- err = -EINVAL;
- if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce))
- goto out;
-
- err = 0;
- prev = 0;
- do {
- for (i = prev; i < next; i++) {
- unsigned long start = jiffies;
- struct mce *m = &mcelog.entry[i];
-
- while (!m->finished) {
- if (time_after_eq(jiffies, start + 2)) {
- memset(m, 0, sizeof(*m));
- goto timeout;
- }
- cpu_relax();
- }
- smp_rmb();
- err |= copy_to_user(buf, m, sizeof(*m));
- buf += sizeof(*m);
-timeout:
- ;
- }
-
- memset(mcelog.entry + prev, 0,
- (next - prev) * sizeof(struct mce));
- prev = next;
- next = cmpxchg(&mcelog.next, prev, 0);
- } while (next != prev);
-
- synchronize_sched();
-
- /*
- * Collect entries that were still getting written before the
- * synchronize.
- */
- on_each_cpu(collect_tscs, cpu_tsc, 1);
-
- for (i = next; i < MCE_LOG_LEN; i++) {
- struct mce *m = &mcelog.entry[i];
-
- if (m->finished && m->tsc < cpu_tsc[m->cpu]) {
- err |= copy_to_user(buf, m, sizeof(*m));
- smp_rmb();
- buf += sizeof(*m);
- memset(m, 0, sizeof(*m));
- }
- }
-
- if (err)
- err = -EFAULT;
-
-out:
- mutex_unlock(&mce_chrdev_read_mutex);
- kfree(cpu_tsc);
-
- return err ? err : buf - ubuf;
-}
-
-static unsigned int mce_chrdev_poll(struct file *file, poll_table *wait)
-{
- poll_wait(file, &mce_chrdev_wait, wait);
- if (READ_ONCE(mcelog.next))
- return POLLIN | POLLRDNORM;
- if (!mce_apei_read_done && apei_check_mce())
- return POLLIN | POLLRDNORM;
- return 0;
-}
-
-static long mce_chrdev_ioctl(struct file *f, unsigned int cmd,
- unsigned long arg)
-{
- int __user *p = (int __user *)arg;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
-
- switch (cmd) {
- case MCE_GET_RECORD_LEN:
- return put_user(sizeof(struct mce), p);
- case MCE_GET_LOG_LEN:
- return put_user(MCE_LOG_LEN, p);
- case MCE_GETCLEAR_FLAGS: {
- unsigned flags;
-
- do {
- flags = mcelog.flags;
- } while (cmpxchg(&mcelog.flags, flags, 0) != flags);
-
- return put_user(flags, p);
- }
- default:
- return -ENOTTY;
- }
-}
-
-void mce_register_injector_chain(struct notifier_block *nb)
-{
- blocking_notifier_chain_register(&mce_injector_chain, nb);
-}
-EXPORT_SYMBOL_GPL(mce_register_injector_chain);
-
-void mce_unregister_injector_chain(struct notifier_block *nb)
-{
- blocking_notifier_chain_unregister(&mce_injector_chain, nb);
-}
-EXPORT_SYMBOL_GPL(mce_unregister_injector_chain);
-
-static ssize_t mce_chrdev_write(struct file *filp, const char __user *ubuf,
- size_t usize, loff_t *off)
-{
- 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.extcpu >= num_possible_cpus() || !cpu_online(m.extcpu))
- return -EINVAL;
-
- /*
- * Need to give user space some time to set everything up,
- * so do it a jiffie or two later everywhere.
- */
- schedule_timeout(2);
-
- blocking_notifier_call_chain(&mce_injector_chain, 0, &m);
-
- return usize;
-}
-
-static const struct file_operations mce_chrdev_ops = {
- .open = mce_chrdev_open,
- .release = mce_chrdev_release,
- .read = mce_chrdev_read,
- .write = mce_chrdev_write,
- .poll = mce_chrdev_poll,
- .unlocked_ioctl = mce_chrdev_ioctl,
- .llseek = no_llseek,
-};
-
-static struct miscdevice mce_chrdev_device = {
- MISC_MCELOG_MINOR,
- "mcelog",
- &mce_chrdev_ops,
-};
-
-static __init int dev_mcelog_init_device(void)
-{
- int err;
-
- /* register character device /dev/mcelog */
- err = misc_register(&mce_chrdev_device);
- if (err) {
- if (err == -EBUSY)
- /* Xen dom0 might have registered the device already. */
- pr_info("Unable to init device /dev/mcelog, already registered");
- else
- pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err);
-
- return err;
- }
-
- mce_register_decode_chain(&dev_mcelog_nb);
- return 0;
-}
-device_initcall_sync(dev_mcelog_init_device);