linux-kernel - Re: KVM-S390: Less function calls in kvm_s390_import_bp

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Date:   Sat, 27 Aug 2016 18:12:33 +0200
From:   SF Markus Elfring <elfring@...rs.sourceforge.net>
To:     Christian Bornträger <borntraeger@...ibm.com>
Cc:     kvm@...r.kernel.org, linux-s390@...r.kernel.org,
        Cornelia Huck <cornelia.huck@...ibm.com>,
        David Hildenbrand <dahi@...ux.vnet.ibm.com>,
        Heiko Carstens <heiko.carstens@...ibm.com>,
        Martin Schwidefsky <schwidefsky@...ibm.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        LKML <linux-kernel@...r.kernel.org>,
        kernel-janitors@...r.kernel.org,
        Julia Lawall <julia.lawall@...6.fr>
Subject: Re: KVM-S390: Less function calls in kvm_s390_import_bp_data() after
 error detection

>> @@ -273,10 +273,12 @@ int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu,
>>  	vcpu->arch.guestdbg.nr_hw_wp = nr_wp;
>>  	vcpu->arch.guestdbg.hw_wp_info = wp_info;
>>  	return 0;
>> -error:
>> -	kfree(bp_data);
>> -	kfree(wp_info);
>> +free_bp_info:
>>  	kfree(bp_info);
>> +free_wp_info:
>> +	kfree(wp_info);
>> +free_bp_data:
>> +	kfree(bp_data);
>>  	return ret;
>>  }
> 
> I agree with Cornelia,

This is generally fine.


> while it seems correct from a technical point of view,

Thanks for another bit of acknowledgement.


> it will make the code harder to maintain.

I agree that there some efforts and challenges involved.


> For example if we ever add a new malloc and remove another one

Do you see any changes coming from this direction?


> over time we would need to reshuffle the labels

This can occasionally happen, can't it?


> and this did went wrong several times in the past.

Would you like to add any corresponding software development experiences
to discussions around a topic like "CodingStyle: add some more error
handling guidelines"?

https://www.spinics.net/lists/linux-doc/msg39307.html
http://marc.info/?l=linux-doc&m=147187538413914

Regards,
Markus