Patch "x86/mce: Don't print MCEs when mcelog is active" has been added to the 4.10-stable tree

This is a note to let you know that I've just added the patch titled

x86/mce: Don't print MCEs when mcelog is active

to the 4.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
x86-mce-don-t-print-mces-when-mcelog-is-active.patch
and it can be found in the queue-4.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Andi Kleen <[email protected]>
Date: Mon, 27 Mar 2017 11:32:59 +0200
Subject: x86/mce: Don't print MCEs when mcelog is active

From: Andi Kleen <[email protected]>

commit cc66afea58f858ff6da7f79b8a595a67bbb4f9a9 upstream.

Since:

cd9c57cad3fe ("x86/MCE: Dump MCE to dmesg if no consumers")

all MCEs are printed even when mcelog is running. Fix the regression to not print to dmesg when mcelog is running as it is a consumer too.

---
 arch/x86/kernel/cpu/mcheck/mce.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

@@ -54,6 +54,8 @@
 
 static DEFINE_MUTEX(mce_chrdev_read_mutex);
 
+static int mce_chrdev_open_count;	/* #times opened */
+
 #define mce_log_get_idx_check(p) \
 ({ \
 	RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \

@@ -601,6 +603,10 @@ static int mce_default_notifier(struct n
 	if (atomic_read(&num_notifiers) > 2)
 		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;

@@ -1871,7 +1877,6 @@ void mcheck_cpu_clear(struct cpuinfo_x86
  */
 
 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)

Patches currently in stable-queue which might be from [email protected] are

queue-4.10/x86-mce-don-t-print-mces-when-mcelog-is-active.patch