From: David Laight <David.Laight@ACULAB.COM>
To: 'Salvatore Mesoraca' <s.mesoraca16@gmail.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
"linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Herbert Xu <herbert@gondor.apana.org.au>,
Kees Cook <keescook@chromium.org>,
Eric Biggers <ebiggers3@gmail.com>,
Laura Abbott <labbott@redhat.com>
Subject: RE: [PATCH v2 0/2] crypto: removing various VLAs
Date: Mon, 9 Apr 2018 14:35:50 +0000 [thread overview]
Message-ID: <ca31b95a8b8e4dab90c5ea2eb6e6477f@AcuMS.aculab.com> (raw)
In-Reply-To: <1523282087-22128-1-git-send-email-s.mesoraca16@gmail.com>
From: Salvatore Mesoraca
> Sent: 09 April 2018 14:55
>
> v2:
> As suggested by Herbert Xu, the blocksize and alignmask checks
> have been moved to crypto_check_alg.
> So, now, all the other separate checks are not necessary.
> Also, the defines have been moved to include/crypto/algapi.h.
>
> v1:
> As suggested by Laura Abbott[1], I'm resending my patch with
> MAX_BLOCKSIZE and MAX_ALIGNMASK defined in an header, so they
> can be used in other places.
> I took this opportunity to deal with some other VLAs not
> handled in the old patch.
If the constants are visible they need better names.
Maybe CRYPTO_MAX_xxx.
You can also do much better than allocating MAX_BLOCKSIZE + MAX_ALIGNMASK
bytes by requesting 'long' aligned on-stack memory.
The easiest way is to define a union like:
union crypto_tmp {
u8 buf[CRYPTO_MAX_TMP_BUF];
long buf_align;
};
Then in each function:
union tmp crypto_tmp;
u8 *keystream = PTR_ALIGN(tmp.buf, alignmask + 1);
I think CRYPTO_MAX_TMP_BUF needs to be MAX_BLOCKSIZE + MAX_ALIGNMASK - sizeof (long).
David
next prev parent reply other threads:[~2018-04-09 14:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-09 13:54 [PATCH v2 0/2] crypto: removing various VLAs Salvatore Mesoraca
2018-04-09 13:54 ` [PATCH v2 1/2] crypto: api - laying defines and checks for statically allocated buffers Salvatore Mesoraca
2018-04-09 13:54 ` [PATCH v2 2/2] crypto: remove several VLAs Salvatore Mesoraca
2018-04-09 14:35 ` David Laight [this message]
2018-04-09 16:38 ` [PATCH v2 0/2] crypto: removing various VLAs Salvatore Mesoraca
2018-04-11 16:20 ` David Laight
2018-04-20 16:51 ` Herbert Xu
2018-04-26 17:27 ` Salvatore Mesoraca
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