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

mathieu souchaud
2014-04-25T17:47:30Z

In this patch, unwindind is still not perfect from the
mce_device_create() calls. I guess, from this point, on error we should
call mce_device_remove on every created device. But I think this will
make the code rather complex. And I am not too confident on this kind of
modification as I don't know much about MCE.

Mathieu S.

Le 25/04/2014 19:40, Mathieu Souchaud a écrit :
> Check return code of every function called.
>
> Signed-off-by: Mathieu Souchaud <mattieu.souchaud@free.fr>
> ---
> arch/x86/kernel/cpu/mcheck/mce.c | 30 +++++++++++++++++++++++-------
> 1 file changed, 23 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
> index 68317c8..b865285 100644
> --- a/arch/x86/kernel/cpu/mcheck/mce.c
> +++ b/arch/x86/kernel/cpu/mcheck/mce.c
> @@ -2437,33 +2437,49 @@ 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_out_mem;
> }
> }
>
> register_syscore_ops(&mce_syscore_ops);
> - __register_hotcpu_notifier(&mce_cpu_notifier);
> + err = __register_hotcpu_notifier(&mce_cpu_notifier);
> cpu_notifier_register_done();
> + if (err)
> + goto err_out_mem;
>
> /* register character device /dev/mcelog */
> - misc_register(&mce_chrdev_device);
> + err = misc_register(&mce_chrdev_device);
> + if (err)
> + goto err_out_mem;
> +
> + return 0;
> +
> +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;
> }
> device_initcall_sync(mcheck_init_device);