#include <linux/fs.h>
#include <linux/cpu.h>
#include <linux/percpu.h>
+#include <linux/ctype.h>
#include <asm/processor.h>
#include <asm/msr.h>
#include <asm/mce.h>
static unsigned long console_logged;
static int notify_user;
static int rip_msr;
+static int mce_bootlog;
/*
* Lockless MCE logging infrastructure.
smp_wmb();
for (;;) {
entry = rcu_dereference(mcelog.next);
- /* When the buffer fills up discard new entries. Assume
- that the earlier errors are the more interesting. */
- if (entry >= MCE_LOG_LEN) {
- set_bit(MCE_OVERFLOW, &mcelog.flags);
- return;
+ for (;;) {
+ /* When the buffer fills up discard new entries. Assume
+ that the earlier errors are the more interesting. */
+ if (entry >= MCE_LOG_LEN) {
+ set_bit(MCE_OVERFLOW, &mcelog.flags);
+ return;
+ }
+ /* Old left over entry. Skip. */
+ if (mcelog.entry[entry].finished) {
+ entry++;
+ continue;
+ }
}
- /* Old left over entry. Skip. */
- if (mcelog.entry[entry].finished)
- continue;
smp_rmb();
next = entry + 1;
if (cmpxchg(&mcelog.next, entry, next) == entry)
rdmsrl(MSR_IA32_MC0_ADDR + i*4, m.addr);
mce_get_rip(&m, regs);
- if (error_code != -1)
+ if (error_code >= 0)
rdtscll(m.tsc);
wrmsrl(MSR_IA32_MC0_STATUS + i*4, 0);
- mce_log(&m);
+ if (error_code != -2)
+ mce_log(&m);
/* Did this bank cause the exception? */
/* Assume that the bank with uncorrectable errors did it,
/* Log the machine checks left over from the previous reset.
This also clears all registers */
- do_machine_check(NULL, -1);
+ do_machine_check(NULL, mce_bootlog ? -1 : -2);
set_in_cr4(X86_CR4_MCE);
}
err = 0;
- for (i = 0; i < next; i++) {
- if (!mcelog.entry[i].finished)
- continue;
+ for (i = 0; i < next; i++) {
+ unsigned long start = jiffies;
+ while (!mcelog.entry[i].finished) {
+ if (!time_before(jiffies, start + 2)) {
+ memset(mcelog.entry + i,0, sizeof(struct mce));
+ continue;
+ }
+ cpu_relax();
+ }
smp_rmb();
err |= copy_to_user(buf, mcelog.entry + i, sizeof(struct mce));
buf += sizeof(struct mce);
}
/* mce=off disables machine check. Note you can reenable it later
- using sysfs */
+ using sysfs.
+ mce=TOLERANCELEVEL (number, see above)
+ mce=bootlog Log MCEs from before booting. Disabled by default to work
+ around buggy BIOS that leave bogus MCEs. */
static int __init mcheck_enable(char *str)
{
+ if (*str == '=')
+ str++;
if (!strcmp(str, "off"))
mce_dont_init = 1;
+ else if (!strcmp(str, "bootlog"))
+ mce_bootlog = 1;
+ else if (isdigit(str[0]))
+ get_option(&str, &tolerant);
else
printk("mce= argument %s ignored. Please use /sys", str);
return 0;