linux-kernel - Re: [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Yl0jPdfdUkaStDN5@gondor.apana.org.au>
Date:   Mon, 18 Apr 2022 16:37:17 +0800
From:   Herbert Xu <herbert@...dor.apana.org.au>
To:     Catalin Marinas <catalin.marinas@....com>
Cc:     Ard Biesheuvel <ardb@...nel.org>, Will Deacon <will@...nel.org>,
        Marc Zyngier <maz@...nel.org>, Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Linux Memory Management List <linux-mm@...ck.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        "David S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of
 ARCH_KMALLOC_MINALIGN

On Sun, Apr 17, 2022 at 05:30:27PM +0100, Catalin Marinas wrote:
>
> Do you mean as per Ard's proposal here:
> 
> https://lore.kernel.org/r/CAMj1kXH0x5Va7Wgs+mU1ONDwwsazOBuN4z4ihVzO2uG-n41Kbg@mail.gmail.com
> 
> struct crypto_request {
> 	union {
> 		struct {
> 			... fields ...
> 		};
> 		u8 __padding[ARCH_DMA_MINALIGN];
> 	};
> 	void __ctx[]  __aligned(CRYPTO_MINALIGN);
> };
> 
> If CRYPTO_MINALIGN is lowered to, say, 8 (to be the same as lowest
> ARCH_KMALLOC_MINALIGN), the __alignof__(req->__ctx) would be 8.
> Functions like crypto_tfm_ctx_alignment() will return 8 when what you
> need is 128. We can change those functions to return ARCH_DMA_MINALIGN
> instead or always bump cra_alignmask to ARCH_DMA_MINALIGN-1.

OK, at this point I think we need to let the code do the talking :)

I've seen Ard's patches already and I think I understand what your
needs are.  So let me whip up some code to show you guys what I
think needs to be done.

Please bear with me for a few days.

Thanks,
-- 
Email: Herbert Xu <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt