[PATCH 9/10] mce: fix cpu hotplug error handling

Akinobu Mita
2007-07-16T14:10:33Z

- Fix error handling in mce_create_device()

Error handling should not do sysdev_remove_file() with not yet added
attributes.

- Change mce_create_device() from CPU_ONLINE event handler
to CPU_UP_PREPARE event handler.

Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>

---
arch/x86_64/kernel/mce.c | 35 ++++++++++++++++++++++++-----------
1 file changed, 24 insertions(+), 11 deletions(-)

Index: 2.6-mm/arch/x86_64/kernel/mce.c
===================================================================
--- 2.6-mm.orig/arch/x86_64/kernel/mce.c
+++ 2.6-mm/arch/x86_64/kernel/mce.c
@@ -803,19 +803,30 @@ static __cpuinit int mce_create_device(u
{
int err;
int i;
- if (!mce_available(&cpu_data[cpu]))
- return -EIO;

+ memset(&per_cpu(device_mce, cpu).kobj, 0, sizeof(struct kobject));
per_cpu(device_mce,cpu).id = cpu;
per_cpu(device_mce,cpu).cls = &mce_sysclass;

err = sysdev_register(&per_cpu(device_mce,cpu));
+ if (err)
+ return err;
+
+ for (i = 0; mce_attributes[i]; i++) {
+ err = sysdev_create_file(&per_cpu(device_mce,cpu),
+ mce_attributes[i]);
+ if (err)
+ goto error;
+ }

- if (!err) {
- for (i = 0; mce_attributes[i]; i++)
- sysdev_create_file(&per_cpu(device_mce,cpu),
- mce_attributes[i]);
+ return 0;
+error:
+ while (i--) {
+ sysdev_remove_file(&per_cpu(device_mce,cpu),
+ mce_attributes[i]);
}
+ sysdev_unregister(&per_cpu(device_mce,cpu));
+
return err;
}

@@ -827,7 +838,6 @@ static void mce_remove_device(unsigned i
sysdev_remove_file(&per_cpu(device_mce,cpu),
mce_attributes[i]);
sysdev_unregister(&per_cpu(device_mce,cpu));
- memset(&per_cpu(device_mce, cpu).kobj, 0, sizeof(struct kobject));
}

/* Get notified when a cpu comes on/off. Be hotplug friendly. */
@@ -835,18 +845,21 @@ static int
mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
+ int err = 0;

switch (action) {
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- mce_create_device(cpu);
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ err = mce_create_device(cpu);
break;
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
case CPU_DEAD_FROZEN:
mce_remove_device(cpu);
break;
}
- return NOTIFY_OK;
+ return err ? NOTIFY_BAD : NOTIFY_OK;
}

static struct notifier_block mce_cpu_notifier = {