From b867059018a5254cca14450eefb6fb8effa0f6dd Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Tue, 20 Jun 2017 23:16:37 +0200 Subject: [PATCH] x86/MCE, xen/mcelog: Make /dev/mcelog registration messages more precise When running under Xen as dom0, /dev/mcelog is being provided by Xen instead of the normal mcelog character device of the MCE core. Convert an error message being issued by the MCE core in this case to an informative message that Xen has registered the device. Signed-off-by: Juergen Gross Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Cc: xen-devel@lists.xenproject.org Cc: Tony Luck Cc: linux-edac Link: http://lkml.kernel.org/r/20170614084059.19294-1-jgross@suse.com --- arch/x86/kernel/cpu/mcheck/dev-mcelog.c | 8 +++++++- drivers/xen/mcelog.c | 2 ++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mcheck/dev-mcelog.c b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c index a80427c30c93..10cec43aac38 100644 --- a/arch/x86/kernel/cpu/mcheck/dev-mcelog.c +++ b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c @@ -415,9 +415,15 @@ static __init int dev_mcelog_init_device(void) /* register character device /dev/mcelog */ err = misc_register(&mce_chrdev_device); if (err) { - pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err); + if (err == -EBUSY) + /* Xen dom0 might have registered the device already. */ + pr_info("Unable to init device /dev/mcelog, already registered"); + else + pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err); + return err; } + mce_register_decode_chain(&dev_mcelog_nb); return 0; } diff --git a/drivers/xen/mcelog.c b/drivers/xen/mcelog.c index a493c7315e94..6cc1c15bcd84 100644 --- a/drivers/xen/mcelog.c +++ b/drivers/xen/mcelog.c @@ -408,6 +408,8 @@ static int __init xen_late_init_mcelog(void) if (ret) goto deregister; + pr_info("/dev/mcelog registered by Xen\n"); + return 0; deregister: -- 2.20.1