tree a4a017f686f101b5817f6c1abbc84518335d497e
parent cf7bee5a0bf270a4eace0be39329d6ac0136cc47
author Andi Kleen <[EMAIL PROTECTED]> Sun, 07 Aug 2005 23:42:07 -0700
committer Linus Torvalds <[EMAIL PROTECTED]> Mon, 08 Aug 2005 00:00:37 -0700
[PATCH] x86_64: ignore machine checks from boot time
Don't log machine check events left over from boot. Too many BIOSes leave
bogus events in there.
This unfortunately also makes it impossible to log events that caused a
reboot. For people with non broken BIOS there is mce=bootlog
Signed-off-by: Andi Kleen <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
Documentation/x86_64/boot-options.txt | 5 +++++
arch/x86_64/kernel/mce.c | 16 ++++++++++++----
2 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/Documentation/x86_64/boot-options.txt
b/Documentation/x86_64/boot-options.txt
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -6,6 +6,11 @@ only the AMD64 specific ones are listed
Machine check
mce=off disable machine check
+ mce=bootlog Enable logging of machine checks left over from booting.
+ Disabled by default because some BIOS leave bogus ones.
+ If your BIOS doesn't do that it's a good idea to enable though
+ to make sure you log even machine check events that result
+ in a reboot.
nomce (for compatibility with i386): same as mce=off
diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c
--- a/arch/x86_64/kernel/mce.c
+++ b/arch/x86_64/kernel/mce.c
@@ -36,6 +36,7 @@ static unsigned long bank[NR_BANKS] = {
static unsigned long console_logged;
static int notify_user;
static int rip_msr;
+static int mce_bootlog;
/*
* Lockless MCE logging infrastructure.
@@ -197,10 +198,11 @@ void do_machine_check(struct pt_regs * r
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,
@@ -315,7 +317,7 @@ static void mce_init(void *dummy)
/* 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);
@@ -476,11 +478,17 @@ static int __init mcheck_disable(char *s
}
/* mce=off disables machine check. Note you can reenable it later
- using sysfs */
+ using sysfs.
+ 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
printk("mce= argument %s ignored. Please use /sys", str);
return 0;
-
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