Re: [PATCH v4 1/9] KVM: Fix srcu struct leakage

[Jan Kiszka <jan.kiszka@siemens.com>]

Am 08.11.2010 18:00, Michael S. Tsirkin wrote:
> On Mon, Nov 08, 2010 at 12:21:45PM +0100, Jan Kiszka wrote:
>> Clean up the srcu struct on vm destruction and refactor its release on
>> early errors.
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> 
> Yay, I suspected something's wrong with error handling in srcu.
> 
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> 
> This one actually has nothing to do with assignment,

Yes, it is just mechanically needed (and I found it while hacking in
more SRCU).

Jan

> and it looks like it's needed for -stable and 2.6.37.
> Avi/Marcelo?
> 
>> ---
>>  virt/kvm/kvm_main.c |   15 +++++++--------
>>  1 files changed, 7 insertions(+), 8 deletions(-)
>>
>> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
>> index 4111a4b..6cfcde7 100644
>> --- a/virt/kvm/kvm_main.c
>> +++ b/virt/kvm/kvm_main.c
>> @@ -401,23 +401,19 @@ static struct kvm *kvm_create_vm(void)
>>  	r = -ENOMEM;
>>  	kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
>>  	if (!kvm->memslots)
>> -		goto out_err;
>> +		goto out_err_nosrcu;
>>  	if (init_srcu_struct(&kvm->srcu))
>> -		goto out_err;
>> +		goto out_err_nosrcu;
>>  	for (i = 0; i < KVM_NR_BUSES; i++) {
>>  		kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
>>  					GFP_KERNEL);
>> -		if (!kvm->buses[i]) {
>> -			cleanup_srcu_struct(&kvm->srcu);
>> +		if (!kvm->buses[i])
>>  			goto out_err;
>> -		}
>>  	}
>>  
>>  	r = kvm_init_mmu_notifier(kvm);
>> -	if (r) {
>> -		cleanup_srcu_struct(&kvm->srcu);
>> +	if (r)
>>  		goto out_err;
>> -	}
>>  
>>  	kvm->mm = current->mm;
>>  	atomic_inc(&kvm->mm->mm_count);
>> @@ -435,6 +431,8 @@ out:
>>  	return kvm;
>>  
>>  out_err:
>> +	cleanup_srcu_struct(&kvm->srcu);
>> +out_err_nosrcu:
>>  	hardware_disable_all();
>>  out_err_nodisable:
>>  	for (i = 0; i < KVM_NR_BUSES; i++)
>> @@ -513,6 +511,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
>>  #else
>>  	kvm_arch_flush_shadow(kvm);
>>  #endif
>> +	cleanup_srcu_struct(&kvm->srcu);
>>  	kvm_arch_destroy_vm(kvm);
>>  	hardware_disable_all();
>>  	mmdrop(mm);
>> -- 
>> 1.7.1

-- 
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