x86/mce: Factor out and deprecate the /dev/mcelog driver
Move all code relating to /dev/mcelog to a separate source file. /dev/mcelog driver can now operate from the machine check notifier with lowest prio. Signed-off-by: Tony Luck <tony.luck@intel.com> [ Move the mce_helper and trigger functionality behind CONFIG_X86_MCELOG_LEGACY. ] Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/20170327093304.10683-6-bp@alien8.de [ Renamed CONFIG_X86_MCELOG to CONFIG_X86_MCELOG_LEGACY. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Tony Luck
Ingo Molnar
parent
011d826111
commit
5de97c9f6d
6 changed files with 426 additions and 364 deletions
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@ -1043,6 +1043,14 @@ config X86_MCE
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The action the kernel takes depends on the severity of the problem,
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ranging from warning messages to halting the machine.
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config X86_MCELOG_LEGACY
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bool "Support for deprecated /dev/mcelog character device"
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depends on X86_MCE
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---help---
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Enable support for /dev/mcelog which is needed by the old mcelog
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userspace logging daemon. Consider switching to the new generation
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rasdaemon solution.
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config X86_MCE_INTEL
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def_bool y
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prompt "Intel MCE features"
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@ -1072,7 +1080,7 @@ config X86_MCE_THRESHOLD
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def_bool y
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config X86_MCE_INJECT
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depends on X86_MCE && X86_LOCAL_APIC
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depends on X86_MCE && X86_LOCAL_APIC && X86_MCELOG_LEGACY
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tristate "Machine check injector support"
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---help---
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Provide support for injecting machine checks for testing purposes.
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@ -196,6 +196,7 @@ enum mce_notifier_prios {
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MCE_PRIO_EXTLOG = INT_MAX - 2,
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MCE_PRIO_NFIT = INT_MAX - 3,
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MCE_PRIO_EDAC = INT_MAX - 4,
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MCE_PRIO_MCELOG = 1,
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MCE_PRIO_LOWEST = 0,
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};
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@ -9,3 +9,5 @@ obj-$(CONFIG_X86_MCE_INJECT) += mce-inject.o
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obj-$(CONFIG_X86_THERMAL_VECTOR) += therm_throt.o
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obj-$(CONFIG_ACPI_APEI) += mce-apei.o
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obj-$(CONFIG_X86_MCELOG_LEGACY) += dev-mcelog.o
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397
arch/x86/kernel/cpu/mcheck/dev-mcelog.c
Normal file
397
arch/x86/kernel/cpu/mcheck/dev-mcelog.c
Normal file
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@ -0,0 +1,397 @@
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/*
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* /dev/mcelog driver
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*
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* K8 parts Copyright 2002,2003 Andi Kleen, SuSE Labs.
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* Rest from unknown author(s).
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* 2004 Andi Kleen. Rewrote most of it.
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* Copyright 2008 Intel Corporation
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* Author: Andi Kleen
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/miscdevice.h>
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#include <linux/slab.h>
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#include <linux/kmod.h>
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#include <linux/poll.h>
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#include "mce-internal.h"
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static DEFINE_MUTEX(mce_chrdev_read_mutex);
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static char mce_helper[128];
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static char *mce_helper_argv[2] = { mce_helper, NULL };
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#define mce_log_get_idx_check(p) \
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({ \
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RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \
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!lockdep_is_held(&mce_chrdev_read_mutex), \
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"suspicious mce_log_get_idx_check() usage"); \
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smp_load_acquire(&(p)); \
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})
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/*
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* Lockless MCE logging infrastructure.
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* This avoids deadlocks on printk locks without having to break locks. Also
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* separate MCEs from kernel messages to avoid bogus bug reports.
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*/
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static struct mce_log_buffer mcelog = {
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.signature = MCE_LOG_SIGNATURE,
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.len = MCE_LOG_LEN,
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.recordlen = sizeof(struct mce),
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};
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static DECLARE_WAIT_QUEUE_HEAD(mce_chrdev_wait);
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/* User mode helper program triggered by machine check event */
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extern char mce_helper[128];
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static int dev_mce_log(struct notifier_block *nb, unsigned long val,
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void *data)
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{
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struct mce *mce = (struct mce *)data;
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unsigned int next, entry;
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wmb();
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for (;;) {
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entry = mce_log_get_idx_check(mcelog.next);
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for (;;) {
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/*
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* When the buffer fills up discard new entries.
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* Assume that the earlier errors are the more
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* interesting ones:
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*/
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if (entry >= MCE_LOG_LEN) {
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set_bit(MCE_OVERFLOW,
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(unsigned long *)&mcelog.flags);
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return NOTIFY_OK;
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}
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/* Old left over entry. Skip: */
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if (mcelog.entry[entry].finished) {
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entry++;
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continue;
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}
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break;
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}
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smp_rmb();
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next = entry + 1;
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if (cmpxchg(&mcelog.next, entry, next) == entry)
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break;
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}
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memcpy(mcelog.entry + entry, mce, sizeof(struct mce));
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wmb();
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mcelog.entry[entry].finished = 1;
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wmb();
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/* wake processes polling /dev/mcelog */
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wake_up_interruptible(&mce_chrdev_wait);
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return NOTIFY_OK;
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}
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static struct notifier_block dev_mcelog_nb = {
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.notifier_call = dev_mce_log,
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.priority = MCE_PRIO_MCELOG,
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};
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static void mce_do_trigger(struct work_struct *work)
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{
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call_usermodehelper(mce_helper, mce_helper_argv, NULL, UMH_NO_WAIT);
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}
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static DECLARE_WORK(mce_trigger_work, mce_do_trigger);
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void mce_work_trigger(void)
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{
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if (mce_helper[0])
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schedule_work(&mce_trigger_work);
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}
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static ssize_t
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show_trigger(struct device *s, struct device_attribute *attr, char *buf)
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{
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strcpy(buf, mce_helper);
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strcat(buf, "\n");
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return strlen(mce_helper) + 1;
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}
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static ssize_t set_trigger(struct device *s, struct device_attribute *attr,
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const char *buf, size_t siz)
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{
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char *p;
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strncpy(mce_helper, buf, sizeof(mce_helper));
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mce_helper[sizeof(mce_helper)-1] = 0;
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p = strchr(mce_helper, '\n');
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if (p)
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*p = 0;
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return strlen(mce_helper) + !!p;
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}
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DEVICE_ATTR(trigger, 0644, show_trigger, set_trigger);
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/*
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* mce_chrdev: Character device /dev/mcelog to read and clear the MCE log.
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*/
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static DEFINE_SPINLOCK(mce_chrdev_state_lock);
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static int mce_chrdev_open_count; /* #times opened */
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static int mce_chrdev_open_exclu; /* already open exclusive? */
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static int mce_chrdev_open(struct inode *inode, struct file *file)
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{
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spin_lock(&mce_chrdev_state_lock);
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if (mce_chrdev_open_exclu ||
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(mce_chrdev_open_count && (file->f_flags & O_EXCL))) {
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spin_unlock(&mce_chrdev_state_lock);
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return -EBUSY;
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}
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if (file->f_flags & O_EXCL)
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mce_chrdev_open_exclu = 1;
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mce_chrdev_open_count++;
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spin_unlock(&mce_chrdev_state_lock);
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return nonseekable_open(inode, file);
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}
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static int mce_chrdev_release(struct inode *inode, struct file *file)
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{
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spin_lock(&mce_chrdev_state_lock);
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mce_chrdev_open_count--;
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mce_chrdev_open_exclu = 0;
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spin_unlock(&mce_chrdev_state_lock);
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return 0;
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}
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static void collect_tscs(void *data)
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{
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unsigned long *cpu_tsc = (unsigned long *)data;
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cpu_tsc[smp_processor_id()] = rdtsc();
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}
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static int mce_apei_read_done;
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/* Collect MCE record of previous boot in persistent storage via APEI ERST. */
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static int __mce_read_apei(char __user **ubuf, size_t usize)
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{
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int rc;
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u64 record_id;
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struct mce m;
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if (usize < sizeof(struct mce))
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return -EINVAL;
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rc = apei_read_mce(&m, &record_id);
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/* Error or no more MCE record */
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if (rc <= 0) {
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mce_apei_read_done = 1;
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/*
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* When ERST is disabled, mce_chrdev_read() should return
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* "no record" instead of "no device."
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*/
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if (rc == -ENODEV)
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return 0;
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return rc;
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}
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rc = -EFAULT;
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if (copy_to_user(*ubuf, &m, sizeof(struct mce)))
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return rc;
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/*
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* In fact, we should have cleared the record after that has
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* been flushed to the disk or sent to network in
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* /sbin/mcelog, but we have no interface to support that now,
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* so just clear it to avoid duplication.
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*/
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rc = apei_clear_mce(record_id);
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if (rc) {
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mce_apei_read_done = 1;
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return rc;
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}
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*ubuf += sizeof(struct mce);
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return 0;
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}
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static ssize_t mce_chrdev_read(struct file *filp, char __user *ubuf,
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size_t usize, loff_t *off)
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{
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char __user *buf = ubuf;
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unsigned long *cpu_tsc;
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unsigned prev, next;
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int i, err;
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cpu_tsc = kmalloc(nr_cpu_ids * sizeof(long), GFP_KERNEL);
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if (!cpu_tsc)
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return -ENOMEM;
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mutex_lock(&mce_chrdev_read_mutex);
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if (!mce_apei_read_done) {
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err = __mce_read_apei(&buf, usize);
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if (err || buf != ubuf)
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goto out;
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}
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next = mce_log_get_idx_check(mcelog.next);
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/* Only supports full reads right now */
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err = -EINVAL;
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if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce))
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goto out;
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err = 0;
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prev = 0;
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do {
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for (i = prev; i < next; i++) {
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unsigned long start = jiffies;
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struct mce *m = &mcelog.entry[i];
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while (!m->finished) {
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if (time_after_eq(jiffies, start + 2)) {
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memset(m, 0, sizeof(*m));
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goto timeout;
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}
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cpu_relax();
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}
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smp_rmb();
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err |= copy_to_user(buf, m, sizeof(*m));
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buf += sizeof(*m);
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timeout:
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;
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}
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memset(mcelog.entry + prev, 0,
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(next - prev) * sizeof(struct mce));
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prev = next;
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next = cmpxchg(&mcelog.next, prev, 0);
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} while (next != prev);
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synchronize_sched();
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/*
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* Collect entries that were still getting written before the
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* synchronize.
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*/
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on_each_cpu(collect_tscs, cpu_tsc, 1);
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for (i = next; i < MCE_LOG_LEN; i++) {
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struct mce *m = &mcelog.entry[i];
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if (m->finished && m->tsc < cpu_tsc[m->cpu]) {
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err |= copy_to_user(buf, m, sizeof(*m));
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smp_rmb();
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buf += sizeof(*m);
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memset(m, 0, sizeof(*m));
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}
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}
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if (err)
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err = -EFAULT;
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out:
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mutex_unlock(&mce_chrdev_read_mutex);
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kfree(cpu_tsc);
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return err ? err : buf - ubuf;
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}
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static unsigned int mce_chrdev_poll(struct file *file, poll_table *wait)
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{
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poll_wait(file, &mce_chrdev_wait, wait);
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if (READ_ONCE(mcelog.next))
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return POLLIN | POLLRDNORM;
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if (!mce_apei_read_done && apei_check_mce())
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return POLLIN | POLLRDNORM;
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return 0;
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}
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static long mce_chrdev_ioctl(struct file *f, unsigned int cmd,
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unsigned long arg)
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{
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int __user *p = (int __user *)arg;
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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switch (cmd) {
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case MCE_GET_RECORD_LEN:
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return put_user(sizeof(struct mce), p);
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case MCE_GET_LOG_LEN:
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return put_user(MCE_LOG_LEN, p);
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case MCE_GETCLEAR_FLAGS: {
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unsigned flags;
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do {
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flags = mcelog.flags;
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} while (cmpxchg(&mcelog.flags, flags, 0) != flags);
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return put_user(flags, p);
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}
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default:
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return -ENOTTY;
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}
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}
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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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void register_mce_write_callback(ssize_t (*fn)(struct file *filp,
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const char __user *ubuf,
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size_t usize, loff_t *off))
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{
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mce_write = fn;
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}
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EXPORT_SYMBOL_GPL(register_mce_write_callback);
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static ssize_t mce_chrdev_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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if (mce_write)
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return mce_write(filp, ubuf, usize, off);
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else
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return -EINVAL;
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}
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static const struct file_operations mce_chrdev_ops = {
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.open = mce_chrdev_open,
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.release = mce_chrdev_release,
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.read = mce_chrdev_read,
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.write = mce_chrdev_write,
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.poll = mce_chrdev_poll,
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.unlocked_ioctl = mce_chrdev_ioctl,
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.llseek = no_llseek,
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};
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static struct miscdevice mce_chrdev_device = {
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MISC_MCELOG_MINOR,
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"mcelog",
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&mce_chrdev_ops,
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};
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static __init int dev_mcelog_init_device(void)
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{
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int err;
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/* register character device /dev/mcelog */
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err = misc_register(&mce_chrdev_device);
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if (err) {
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pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err);
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return err;
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}
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mce_register_decode_chain(&dev_mcelog_nb);
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return 0;
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}
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device_initcall_sync(dev_mcelog_init_device);
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@ -96,3 +96,11 @@ static inline bool mce_cmp(struct mce *m1, struct mce *m2)
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m1->addr != m2->addr ||
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m1->misc != m2->misc;
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}
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extern struct device_attribute dev_attr_trigger;
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#ifdef CONFIG_X86_MCELOG_LEGACY
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extern void mce_work_trigger(void);
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#else
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static inline void mce_work_trigger(void) { }
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#endif
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@ -54,17 +54,7 @@
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#include "mce-internal.h"
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static DEFINE_MUTEX(mce_chrdev_read_mutex);
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static int mce_chrdev_open_count; /* #times opened */
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#define mce_log_get_idx_check(p) \
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({ \
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RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \
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!lockdep_is_held(&mce_chrdev_read_mutex), \
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"suspicious mce_log_get_idx_check() usage"); \
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smp_load_acquire(&(p)); \
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})
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static DEFINE_MUTEX(mce_log_mutex);
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#define CREATE_TRACE_POINTS
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#include <trace/events/mce.h>
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|
|
@ -89,15 +79,9 @@ struct mca_config mca_cfg __read_mostly = {
|
|||
.monarch_timeout = -1
|
||||
};
|
||||
|
||||
/* User mode helper program triggered by machine check event */
|
||||
static unsigned long mce_need_notify;
|
||||
static char mce_helper[128];
|
||||
static char *mce_helper_argv[2] = { mce_helper, NULL };
|
||||
|
||||
static DECLARE_WAIT_QUEUE_HEAD(mce_chrdev_wait);
|
||||
|
||||
static DEFINE_PER_CPU(struct mce, mces_seen);
|
||||
static int cpu_missing;
|
||||
static unsigned long mce_need_notify;
|
||||
static int cpu_missing;
|
||||
|
||||
/*
|
||||
* MCA banks polled by the period polling timer for corrected events.
|
||||
|
|
@ -147,18 +131,6 @@ void mce_setup(struct mce *m)
|
|||
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
|
||||
* separate MCEs from kernel messages to avoid bogus bug reports.
|
||||
*/
|
||||
|
||||
static struct mce_log_buffer mcelog_buf = {
|
||||
.signature = MCE_LOG_SIGNATURE,
|
||||
.len = MCE_LOG_LEN,
|
||||
.recordlen = sizeof(struct mce),
|
||||
};
|
||||
|
||||
void mce_log(struct mce *m)
|
||||
{
|
||||
if (!mce_gen_pool_add(m))
|
||||
|
|
@ -167,9 +139,9 @@ void mce_log(struct mce *m)
|
|||
|
||||
void mce_inject_log(struct mce *m)
|
||||
{
|
||||
mutex_lock(&mce_chrdev_read_mutex);
|
||||
mutex_lock(&mce_log_mutex);
|
||||
mce_log(m);
|
||||
mutex_unlock(&mce_chrdev_read_mutex);
|
||||
mutex_unlock(&mce_log_mutex);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(mce_inject_log);
|
||||
|
||||
|
|
@ -582,7 +554,6 @@ static int mce_first_notifier(struct notifier_block *nb, unsigned long val,
|
|||
void *data)
|
||||
{
|
||||
struct mce *m = (struct mce *)data;
|
||||
unsigned int next, entry;
|
||||
|
||||
if (!m)
|
||||
return NOTIFY_DONE;
|
||||
|
|
@ -593,38 +564,6 @@ static int mce_first_notifier(struct notifier_block *nb, unsigned long val,
|
|||
/* Emit the trace record: */
|
||||
trace_mce_record(m);
|
||||
|
||||
wmb();
|
||||
for (;;) {
|
||||
entry = mce_log_get_idx_check(mcelog_buf.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_buf.flags);
|
||||
return NOTIFY_DONE;
|
||||
}
|
||||
/* Old left over entry. Skip: */
|
||||
if (mcelog_buf.entry[entry].finished) {
|
||||
entry++;
|
||||
continue;
|
||||
}
|
||||
break;
|
||||
}
|
||||
smp_rmb();
|
||||
next = entry + 1;
|
||||
if (cmpxchg(&mcelog_buf.next, entry, next) == entry)
|
||||
break;
|
||||
}
|
||||
memcpy(mcelog_buf.entry + entry, m, sizeof(struct mce));
|
||||
wmb();
|
||||
mcelog_buf.entry[entry].finished = 1;
|
||||
wmb();
|
||||
|
||||
set_bit(0, &mce_need_notify);
|
||||
|
||||
mce_notify_irq();
|
||||
|
|
@ -669,10 +608,6 @@ static int mce_default_notifier(struct notifier_block *nb, unsigned long val,
|
|||
if (atomic_read(&num_notifiers) > NUM_DEFAULT_NOTIFIERS)
|
||||
return NOTIFY_DONE;
|
||||
|
||||
/* Don't print when mcelog is running */
|
||||
if (mce_chrdev_open_count > 0)
|
||||
return NOTIFY_DONE;
|
||||
|
||||
__print_mce(m);
|
||||
|
||||
return NOTIFY_DONE;
|
||||
|
|
@ -1456,13 +1391,6 @@ static void mce_timer_delete_all(void)
|
|||
del_timer_sync(&per_cpu(mce_timer, cpu));
|
||||
}
|
||||
|
||||
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);
|
||||
|
||||
/*
|
||||
* Notify the user(s) about new machine check events.
|
||||
* Can be called from interrupt context, but not from machine check/NMI
|
||||
|
|
@ -1474,11 +1402,7 @@ int mce_notify_irq(void)
|
|||
static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);
|
||||
|
||||
if (test_and_clear_bit(0, &mce_need_notify)) {
|
||||
/* wake processes polling /dev/mcelog */
|
||||
wake_up_interruptible(&mce_chrdev_wait);
|
||||
|
||||
if (mce_helper[0])
|
||||
schedule_work(&mce_trigger_work);
|
||||
mce_work_trigger();
|
||||
|
||||
if (__ratelimit(&ratelimit))
|
||||
pr_info(HW_ERR "Machine check events logged\n");
|
||||
|
|
@ -1886,251 +1810,6 @@ void mcheck_cpu_clear(struct cpuinfo_x86 *c)
|
|||
|
||||
}
|
||||
|
||||
/*
|
||||
* 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_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_buf.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_buf.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_buf.entry + prev, 0,
|
||||
(next - prev) * sizeof(struct mce));
|
||||
prev = next;
|
||||
next = cmpxchg(&mcelog_buf.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_buf.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_buf.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_buf.flags;
|
||||
} while (cmpxchg(&mcelog_buf.flags, flags, 0) != flags);
|
||||
|
||||
return put_user(flags, p);
|
||||
}
|
||||
default:
|
||||
return -ENOTTY;
|
||||
}
|
||||
}
|
||||
|
||||
static ssize_t (*mce_write)(struct file *filp, const char __user *ubuf,
|
||||
size_t usize, loff_t *off);
|
||||
|
||||
void register_mce_write_callback(ssize_t (*fn)(struct file *filp,
|
||||
const char __user *ubuf,
|
||||
size_t usize, loff_t *off))
|
||||
{
|
||||
mce_write = fn;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(register_mce_write_callback);
|
||||
|
||||
static ssize_t mce_chrdev_write(struct file *filp, const char __user *ubuf,
|
||||
size_t usize, loff_t *off)
|
||||
{
|
||||
if (mce_write)
|
||||
return mce_write(filp, ubuf, usize, off);
|
||||
else
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
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 void __mce_disable_bank(void *arg)
|
||||
{
|
||||
int bank = *((int *)arg);
|
||||
|
|
@ -2349,29 +2028,6 @@ static ssize_t set_bank(struct device *s, struct device_attribute *attr,
|
|||
return size;
|
||||
}
|
||||
|
||||
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;
|
||||
}
|
||||
|
||||
static ssize_t set_ignore_ce(struct device *s,
|
||||
struct device_attribute *attr,
|
||||
const char *buf, size_t size)
|
||||
|
|
@ -2428,7 +2084,6 @@ static ssize_t store_int_with_restart(struct device *s,
|
|||
return ret;
|
||||
}
|
||||
|
||||
static DEVICE_ATTR(trigger, 0644, show_trigger, set_trigger);
|
||||
static DEVICE_INT_ATTR(tolerant, 0644, mca_cfg.tolerant);
|
||||
static DEVICE_INT_ATTR(monarch_timeout, 0644, mca_cfg.monarch_timeout);
|
||||
static DEVICE_BOOL_ATTR(dont_log_ce, 0644, mca_cfg.dont_log_ce);
|
||||
|
|
@ -2451,7 +2106,9 @@ static struct dev_ext_attribute dev_attr_cmci_disabled = {
|
|||
static struct device_attribute *mce_device_attrs[] = {
|
||||
&dev_attr_tolerant.attr,
|
||||
&dev_attr_check_interval.attr,
|
||||
#ifdef CONFIG_X86_MCELOG_LEGACY
|
||||
&dev_attr_trigger,
|
||||
#endif
|
||||
&dev_attr_monarch_timeout.attr,
|
||||
&dev_attr_dont_log_ce.attr,
|
||||
&dev_attr_ignore_ce.attr,
|
||||
|
|
@ -2625,7 +2282,6 @@ static __init void mce_init_banks(void)
|
|||
|
||||
static __init int mcheck_init_device(void)
|
||||
{
|
||||
enum cpuhp_state hp_online;
|
||||
int err;
|
||||
|
||||
if (!mce_available(&boot_cpu_data)) {
|
||||
|
|
@ -2653,21 +2309,11 @@ static __init int mcheck_init_device(void)
|
|||
mce_cpu_online, mce_cpu_pre_down);
|
||||
if (err < 0)
|
||||
goto err_out_online;
|
||||
hp_online = err;
|
||||
|
||||
register_syscore_ops(&mce_syscore_ops);
|
||||
|
||||
/* register character device /dev/mcelog */
|
||||
err = misc_register(&mce_chrdev_device);
|
||||
if (err)
|
||||
goto err_register;
|
||||
|
||||
return 0;
|
||||
|
||||
err_register:
|
||||
unregister_syscore_ops(&mce_syscore_ops);
|
||||
cpuhp_remove_state(hp_online);
|
||||
|
||||
err_out_online:
|
||||
cpuhp_remove_state(CPUHP_X86_MCE_DEAD);
|
||||
|
||||
|
|
@ -2675,7 +2321,7 @@ static __init int mcheck_init_device(void)
|
|||
free_cpumask_var(mce_device_initialized);
|
||||
|
||||
err_out:
|
||||
pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err);
|
||||
pr_err("Unable to init MCE device (rc: %d)\n", err);
|
||||
|
||||
return err;
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in a new issue