linux-kernel - RE: [PATCH] cifs: Remove locking in smb2_verify_signature() when calculating SMB2/SMB3 signature on receiving packets

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Date:   Fri, 27 Mar 2020 12:05:23 +0100
From:   Aurélien Aptel <aaptel@...e.com>
To:     Long Li <longli@...rosoft.com>,
        "longli\@linuxonhyperv.com" <longli@...uxonhyperv.com>,
        Steve French <sfrench@...ba.org>,
        "linux-cifs\@vger.kernel.org" <linux-cifs@...r.kernel.org>,
        "samba-technical\@lists.samba.org" <samba-technical@...ts.samba.org>,
        "linux-kernel\@vger.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] cifs: Remove locking in smb2_verify_signature() when
 calculating SMB2/SMB3 signature on receiving packets

Long Li <longli@...rosoft.com> writes:
>>need for locks). AFAIK there's no state that need to be kept between
>>signing/encrypting calls beside the access to keys. Is it that expensive to
>>create/release?
>
> My guess is that crypto_alloc_shash() is a heavy call?

AFAIK there's no IO, just some memory allocation. Could be faster than
locking. Something to look into, maybe...

Cheers,
-- 
Aurélien Aptel / SUSE Labs Samba Team
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