Re: [PATCH] crypto: af_alg - add async support to algif_aead

From: Tadeusz Struk
Date: Tue Jan 19 2016 - 10:22:30 EST

On 01/18/2016 04:34 PM, Herbert Xu wrote:
>> My understanding is that the sock_kmalloc is mainly used for allocations
>> > of the user provided data, because it keeps tracks of how much memory
>> > is allocated by a socket, and makes sure that is will not exceed the
>> > sysctl_optmem_max limit. Usually the internal structures, with fixed
>> > size are allocated simply with kmalloc. I don't think that using
>> > sock_kmalloc will give us any benefit here.
> If there is only ever one of them per-socket then kmalloc is fine,
> otherwise you should use sock_kmalloc.

There is one per request. There can be a few of them at a given time.
We have the same thing in skcipher and we use kmalloc there.

>> I agree that they are very similar, but I found it much easier to debug
>> > when they are separate functions. I would prefer to keep them separate.
>> > They are also separate in algif_skcipher. It makes it also easier to
>> > read and understand.
> I too would prefer a common function. However we can do this
> later if we wish.

lets do this later then.

>> > The inflight ctr is incremented only if an asynchronous request has been
>> > successfully en-queued for processing. If a user forges to call recvmsg
>> > then the function that increments it won't be even called.
>> > >From the other hand we don't want to give the option to interrupt the
>> > wait, because in a case, when we do have request being processed by some
>> > hardware, and the user kills the process, causing the socket to be
>> > freed, then we will get an Oops in the callback.
> This should be replaced with a sock_hold.

Ok, I will try sock_hold.