From b5975917a3e5f93b5d1c95561aab0aa44327baea Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 19 Jul 2012 13:59:38 -0400 Subject: [PATCH] x86: mce: Serialize mce injection raise_mce() fiddles with global state, but lacks any kind of serialization. Add a mutex around the raise_mce() call, so concurrent writers do not stomp on each other toes. Signed-off-by: Thomas Gleixner Signed-off-by: Chen Gong Signed-off-by: Tony Luck --- arch/x86/kernel/cpu/mcheck/mce-inject.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c index 753746f6dbd807..ddc72f8393321d 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-inject.c +++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c @@ -78,6 +78,7 @@ static void raise_exception(struct mce *m, struct pt_regs *pregs) } static cpumask_var_t mce_inject_cpumask; +static DEFINE_MUTEX(mce_inject_mutex); static int mce_raise_notify(unsigned int cmd, struct pt_regs *regs) { @@ -229,7 +230,10 @@ static ssize_t mce_write(struct file *filp, const char __user *ubuf, * so do it a jiffie or two later everywhere. */ schedule_timeout(2); + + mutex_lock(&mce_inject_mutex); raise_mce(&m); + mutex_unlock(&mce_inject_mutex); return usize; }