From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Xu <peterx@redhat.com>
Date: Tue, 24 Dec 2019 18:19:30 +0000
Subject: Re: [PATCH v4 16/19] KVM: Ensure validity of memslot with respect to kvm_get_dirty_log()
Message-Id: <20191224181930.GC17176@xz-x1>
List-Id: <kvm-ppc.vger.kernel.org>
References: <20191217204041.10815-1-sean.j.christopherson@intel.com>
 <20191217204041.10815-17-sean.j.christopherson@intel.com>
In-Reply-To: <20191217204041.10815-17-sean.j.christopherson@intel.com>
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To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: James Hogan <jhogan@kernel.org>, Paul Mackerras <paulus@ozlabs.org>, Christian Borntraeger <borntraeger@de.ibm.com>, Janosch Frank <frankja@linux.ibm.com>, Paolo Bonzini <pbonzini@redhat.com>, Marc Zyngier <maz@kernel.org>, linux-arm-kernel@lists.infradead.org, Wanpeng Li <wanpengli@tencent.com>, Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= <f4bug@amsat.org>, kvm@vger.kernel.org, David Hildenbrand <david@redhat.com>, Joerg Roedel <joro@8bytes.org>, Cornelia Huck <cohuck@redhat.com>, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, Vitaly Kuznetsov <vkuznets@redhat.com>, kvmarm@lists.cs.columbia.edu, Jim Mattson <jmattson@google.com>

On Tue, Dec 17, 2019 at 12:40:38PM -0800, Sean Christopherson wrote:
> +int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
> +		      int *is_dirty, struct kvm_memory_slot **memslot)
>  {
>  	struct kvm_memslots *slots;
> -	struct kvm_memory_slot *memslot;
>  	int i, as_id, id;
>  	unsigned long n;
>  	unsigned long any = 0;
>  
> +	*memslot = NULL;
> +	*is_dirty = 0;
> +
>  	as_id = log->slot >> 16;
>  	id = (u16)log->slot;
>  	if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
>  		return -EINVAL;
>  
>  	slots = __kvm_memslots(kvm, as_id);
> -	memslot = id_to_memslot(slots, id);
> -	if (!memslot->dirty_bitmap)
> +	*memslot = id_to_memslot(slots, id);
> +	if (!(*memslot)->dirty_bitmap)
>  		return -ENOENT;
>  
> -	n = kvm_dirty_bitmap_bytes(memslot);
> +	kvm_arch_sync_dirty_log(kvm, *memslot);

Should this line belong to previous patch?

> +
> +	n = kvm_dirty_bitmap_bytes(*memslot);
>  
>  	for (i = 0; !any && i < n/sizeof(long); ++i)
> -		any = memslot->dirty_bitmap[i];
> +		any = (*memslot)->dirty_bitmap[i];
>  
> -	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
> +	if (copy_to_user(log->dirty_bitmap, (*memslot)->dirty_bitmap, n))
>  		return -EFAULT;
>  
>  	if (any)
> -- 
> 2.24.1

-- 
Peter Xu