73 lines
2.3 KiB
Diff
73 lines
2.3 KiB
Diff
|
From 26df8496fdb73e9ae2bdf9d1684484196260a8f3 Mon Sep 17 00:00:00 2001
|
||
|
|
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
|
||
|
|
<marmarek@invisiblethingslab.com>
|
||
|
|
Date: Tue, 5 Jan 2016 02:44:04 +0100
|
||
|
|
Subject: [PATCH] mce: hide EBUSY initialization error on Xen
|
||
|
|
MIME-Version: 1.0
|
||
|
|
Content-Type: text/plain; charset=UTF-8
|
||
|
|
Content-Transfer-Encoding: 8bit
|
||
|
|
Organization: Invisible Things Lab
|
||
|
|
Cc: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
|
||
|
|
|
||
|
|
In case of Xen, the device is already registered by xen mcelog (in
|
||
|
|
xen_late_init_mcelog), so fail here is expected. Note that
|
||
|
|
mcheck_init_device call is still expected to initialize mce_device. Comment
|
||
|
|
from threshold_init_device explaining the situation:
|
||
|
|
|
||
|
|
/*
|
||
|
|
* there are 3 funcs which need to be _initcalled in a logic sequence:
|
||
|
|
* 1. xen_late_init_mcelog
|
||
|
|
* 2. mcheck_init_device
|
||
|
|
* 3. threshold_init_device
|
||
|
|
*
|
||
|
|
* xen_late_init_mcelog must register xen_mce_chrdev_device before
|
||
|
|
* native mce_chrdev_device registration if running under xen platform;
|
||
|
|
*
|
||
|
|
* mcheck_init_device should be inited before threshold_init_device to
|
||
|
|
* initialize mce_device, otherwise a NULL ptr dereference will cause panic.
|
||
|
|
*
|
||
|
|
* so we use following _initcalls
|
||
|
|
* 1. device_initcall(xen_late_init_mcelog);
|
||
|
|
* 2. device_initcall_sync(mcheck_init_device);
|
||
|
|
* 3. late_initcall(threshold_init_device);
|
||
|
|
*
|
||
|
|
* when running under xen, the initcall order is 1,2,3;
|
||
|
|
* on baremetal, we skip 1 and we do only 2 and 3.
|
||
|
|
*/
|
||
|
|
|
||
|
|
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
|
||
|
|
---
|
||
|
|
arch/x86/kernel/cpu/mcheck/mce.c | 9 +++++++++
|
||
|
|
1 file changed, 9 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
|
||
|
|
index c5b0d56..69b0b4b 100644
|
||
|
|
--- a/arch/x86/kernel/cpu/mcheck/mce.c
|
||
|
|
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
|
||
|
|
@@ -48,6 +48,10 @@
|
||
|
|
#include <asm/mce.h>
|
||
|
|
#include <asm/msr.h>
|
||
|
|
|
||
|
|
+#ifdef CONFIG_XEN_MCE_LOG
|
||
|
|
+#include <xen/xen.h>
|
||
|
|
+#endif
|
||
|
|
+
|
||
|
|
#include "mce-internal.h"
|
||
|
|
|
||
|
|
static DEFINE_MUTEX(mce_chrdev_read_mutex);
|
||
|
|
@@ -2512,6 +2516,11 @@ err_out_mem:
|
||
|
|
free_cpumask_var(mce_device_initialized);
|
||
|
|
|
||
|
|
err_out:
|
||
|
|
+#ifdef CONFIG_XEN_MCE_LOG
|
||
|
|
+ /* in case of Xen, the character device was already registered, so do not
|
||
|
|
+ * treat this as an error */
|
||
|
|
+ if (!xen_initial_domain() || err != -EBUSY)
|
||
|
|
+#endif
|
||
|
|
pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err);
|
||
|
|
|
||
|
|
return err;
|
||
|
|
--
|
||
|
|
2.1.0
|
||
|
|
|