From cc66afea58f858ff6da7f79b8a595a67bbb4f9a9 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Mon, 27 Mar 2017 11:32:59 +0200 Subject: [PATCH] x86/mce: Don't print MCEs when mcelog is active 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. Signed-off-by: Andi Kleen [ Massage commit message. ] Signed-off-by: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Cc: linux-edac Cc: stable@vger.kernel.org # 4.10.. Fixes: cd9c57cad3fe ("x86/MCE: Dump MCE to dmesg if no consumers") Link: http://lkml.kernel.org/r/20170327093304.10683-2-bp@alien8.de Signed-off-by: Ingo Molnar Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/mcheck/mce.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 8e9725c607ea..5accfbdee3f0 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -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() && \ @@ -598,6 +600,10 @@ static int mce_default_notifier(struct notifier_block *nb, unsigned long val, 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; @@ -1828,7 +1834,6 @@ void mcheck_cpu_clear(struct cpuinfo_x86 *c) */ 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)