[PATCH v3] x86/mce: Improve mcheck_init_device() error handling

From: Mathieu Souchaud
Date: Wed May 28 2014 - 03:13:16 EST


Check return code of every function called by mcheck_init_device().

Signed-off-by: Mathieu Souchaud <mattieu.souchaud@xxxxxxx>
---
arch/x86/kernel/cpu/mcheck/mce.c | 47 ++++++++++++++++++++++++++++++++------
1 file changed, 40 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 68317c8..e361681 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -2437,32 +2437,65 @@ static __init int mcheck_init_device(void)
int err;
int i = 0;

- if (!mce_available(&boot_cpu_data))
- return -EIO;
+ if (!mce_available(&boot_cpu_data)) {
+ err = -EIO;
+ goto err_out;
+ }

- zalloc_cpumask_var(&mce_device_initialized, GFP_KERNEL);
+ if (!zalloc_cpumask_var(&mce_device_initialized, GFP_KERNEL)) {
+ err = -ENOMEM;
+ goto err_out;
+ }

mce_init_banks();

err = subsys_system_register(&mce_subsys, NULL);
if (err)
- return err;
+ goto err_out_mem;

cpu_notifier_register_begin();
for_each_online_cpu(i) {
err = mce_device_create(i);
if (err) {
cpu_notifier_register_done();
- return err;
+ goto err_device_create;
}
}

- register_syscore_ops(&mce_syscore_ops);
__register_hotcpu_notifier(&mce_cpu_notifier);
cpu_notifier_register_done();

+ register_syscore_ops(&mce_syscore_ops);
+
/* register character device /dev/mcelog */
- misc_register(&mce_chrdev_device);
+ err = misc_register(&mce_chrdev_device);
+ if (err)
+ goto err_register;
+
+ return 0;
+
+err_register:
+ unregister_syscore_ops(&mce_syscore_ops);
+
+ cpu_notifier_register_begin();
+ __unregister_hotcpu_notifier(&mce_cpu_notifier);
+ cpu_notifier_register_done();
+
+err_device_create:
+ /*
+ * We didn't keep track of which devices were created above, but
+ * even if we had, the set of online cpus might have changed.
+ * Play safe and remove for every possible cpu, since
+ * mce_device_remove() will do the right thing.
+ */
+ for_each_possible_cpu(i)
+ mce_device_remove(i);
+
+err_out_mem:
+ free_cpumask_var(mce_device_initialized);
+
+err_out:
+ pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err);

return err;
}
--
1.7.9.5

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