From: Catalin Marinas <catalin.marinas@arm.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ard Biesheuvel <ardb@kernel.org>, Will Deacon <will@kernel.org>,
Marc Zyngier <maz@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linux Memory Management List <linux-mm@kvack.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN
Date: Fri, 15 Apr 2022 10:51:40 +0100 [thread overview]
Message-ID: <YllALIgZcQJ6asdA@arm.com> (raw)
In-Reply-To: <YlkkGpVx8rhcsBot@gondor.apana.org.au>
On Fri, Apr 15, 2022 at 03:51:54PM +0800, Herbert Xu wrote:
> On Fri, Apr 15, 2022 at 09:49:12AM +0200, Ard Biesheuvel wrote:
> > I'm not sure I understand what would go wrong if that assumption no
> > longer holds.
>
> It's very simple, we don't do anything to the pointer returned
> by kmalloc before returning it as a tfm or other object with
> an alignment of CRYPTO_MINALIGN. IOW if kmalloc starts returning
> pointers that are not aligned to CRYPTO_MINALIGN then we'd be
> lying to the compiler.
I agree that it would be lying to the compiler, but I don't think this
matters for arm64 where the CPU can do unaligned accesses just fine. We
don't even end up with unaligned accesses here. Let's say we have:
struct x {
...
} __attribute__ ((__aligned__ (128)));
and the kmalloc(sizeof(struct x)) returns a 64-byte aligned pointer. The
compiler-generated code won't have any problem on arm64 accessing the
struct x members. As I said a few times, it's not affecting any other
architecture and not breaking arm64 either.
Anyway, let's agree to disagree. I'll look into keeping CRYPTO_MINALIGN
as ARCH_KMALLOC_MINALIGN and introduce a CRYPTO_DMA_MINALIGN (or just
use ARCH_DMA_MINALIGN directly) together with something like Linus'
dma_kmalloc() in places where an object aligned to ARCH_DMA_MINALIGN is
needed in the crypto code.
--
Catalin
WARNING: multiple messages have this Message-ID (diff)
From: Catalin Marinas <catalin.marinas@arm.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ard Biesheuvel <ardb@kernel.org>, Will Deacon <will@kernel.org>,
Marc Zyngier <maz@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linux Memory Management List <linux-mm@kvack.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN
Date: Fri, 15 Apr 2022 10:51:40 +0100 [thread overview]
Message-ID: <YllALIgZcQJ6asdA@arm.com> (raw)
In-Reply-To: <YlkkGpVx8rhcsBot@gondor.apana.org.au>
On Fri, Apr 15, 2022 at 03:51:54PM +0800, Herbert Xu wrote:
> On Fri, Apr 15, 2022 at 09:49:12AM +0200, Ard Biesheuvel wrote:
> > I'm not sure I understand what would go wrong if that assumption no
> > longer holds.
>
> It's very simple, we don't do anything to the pointer returned
> by kmalloc before returning it as a tfm or other object with
> an alignment of CRYPTO_MINALIGN. IOW if kmalloc starts returning
> pointers that are not aligned to CRYPTO_MINALIGN then we'd be
> lying to the compiler.
I agree that it would be lying to the compiler, but I don't think this
matters for arm64 where the CPU can do unaligned accesses just fine. We
don't even end up with unaligned accesses here. Let's say we have:
struct x {
...
} __attribute__ ((__aligned__ (128)));
and the kmalloc(sizeof(struct x)) returns a 64-byte aligned pointer. The
compiler-generated code won't have any problem on arm64 accessing the
struct x members. As I said a few times, it's not affecting any other
architecture and not breaking arm64 either.
Anyway, let's agree to disagree. I'll look into keeping CRYPTO_MINALIGN
as ARCH_KMALLOC_MINALIGN and introduce a CRYPTO_DMA_MINALIGN (or just
use ARCH_DMA_MINALIGN directly) together with something like Linus'
dma_kmalloc() in places where an object aligned to ARCH_DMA_MINALIGN is
needed in the crypto code.
--
Catalin
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-04-15 9:51 UTC|newest]
Thread overview: 287+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-05 13:57 [PATCH 00/10] mm, arm64: Reduce ARCH_KMALLOC_MINALIGN below the cache line size Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 01/10] mm/slab: Decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-05 23:59 ` Hyeonggon Yoo
2022-04-05 23:59 ` Hyeonggon Yoo
2022-04-06 7:29 ` Arnd Bergmann
2022-04-06 7:29 ` Arnd Bergmann
2022-04-06 12:09 ` Hyeonggon Yoo
2022-04-06 12:09 ` Hyeonggon Yoo
2022-04-06 8:53 ` Catalin Marinas
2022-04-06 8:53 ` Catalin Marinas
2022-04-06 2:01 ` kernel test robot
2022-04-06 8:56 ` Catalin Marinas
2022-04-06 8:56 ` Catalin Marinas
2022-04-06 12:18 ` [kbuild-all] " Chen, Rong A
2022-04-08 6:42 ` Hyeonggon Yoo
2022-04-08 6:42 ` Hyeonggon Yoo
2022-04-08 9:06 ` Hyeonggon Yoo
2022-04-08 9:06 ` Hyeonggon Yoo
2022-04-08 9:11 ` Catalin Marinas
2022-04-08 9:11 ` Catalin Marinas
2022-04-11 10:37 ` Hyeonggon Yoo
2022-04-11 10:37 ` Hyeonggon Yoo
2022-04-11 14:02 ` Catalin Marinas
2022-04-11 14:02 ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 02/10] drivers/base: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-11 14:57 ` Andy Shevchenko
2022-04-11 14:57 ` Andy Shevchenko
2022-04-11 17:39 ` Catalin Marinas
2022-04-11 17:39 ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 03/10] drivers/gpu: " Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 04/10] drivers/md: " Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 05/10] drivers/spi: " Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-05 14:05 ` Mark Brown
2022-04-05 14:05 ` Mark Brown
2022-04-05 13:57 ` [PATCH 06/10] drivers/usb: " Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 07/10] crypto: " Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-05 22:57 ` Herbert Xu
2022-04-05 22:57 ` Herbert Xu
2022-04-06 6:53 ` Ard Biesheuvel
2022-04-06 6:53 ` Ard Biesheuvel
2022-04-06 8:49 ` Catalin Marinas
2022-04-06 8:49 ` Catalin Marinas
2022-04-06 9:41 ` Ard Biesheuvel
2022-04-06 9:41 ` Ard Biesheuvel
2022-04-07 4:30 ` Herbert Xu
2022-04-07 4:30 ` Herbert Xu
2022-04-07 11:01 ` Catalin Marinas
2022-04-07 11:01 ` Catalin Marinas
2022-04-07 11:40 ` Herbert Xu
2022-04-07 11:40 ` Herbert Xu
2022-04-07 16:28 ` Catalin Marinas
2022-04-07 16:28 ` Catalin Marinas
2022-04-08 3:25 ` Herbert Xu
2022-04-08 3:25 ` Herbert Xu
2022-04-08 9:04 ` Catalin Marinas
2022-04-08 9:04 ` Catalin Marinas
2022-04-08 9:11 ` Herbert Xu
2022-04-08 9:11 ` Herbert Xu
2022-04-12 9:32 ` Catalin Marinas
2022-04-12 9:32 ` Catalin Marinas
2022-04-12 9:40 ` Herbert Xu
2022-04-12 9:40 ` Herbert Xu
2022-04-12 10:02 ` Catalin Marinas
2022-04-12 10:02 ` Catalin Marinas
2022-04-12 10:18 ` Herbert Xu
2022-04-12 10:18 ` Herbert Xu
2022-04-12 12:31 ` Catalin Marinas
2022-04-12 12:31 ` Catalin Marinas
2022-04-12 22:01 ` Ard Biesheuvel
2022-04-12 22:01 ` Ard Biesheuvel
2022-04-13 8:47 ` Catalin Marinas
2022-04-13 8:47 ` Catalin Marinas
2022-04-13 19:53 ` Linus Torvalds
2022-04-13 19:53 ` Linus Torvalds
2022-04-14 5:38 ` Greg Kroah-Hartman
2022-04-14 5:38 ` Greg Kroah-Hartman
2022-04-14 13:52 ` Ard Biesheuvel
2022-04-14 13:52 ` Ard Biesheuvel
2022-04-14 14:27 ` Greg Kroah-Hartman
2022-04-14 14:27 ` Greg Kroah-Hartman
2022-04-14 14:36 ` Ard Biesheuvel
2022-04-14 14:36 ` Ard Biesheuvel
2022-04-14 14:52 ` Greg Kroah-Hartman
2022-04-14 14:52 ` Greg Kroah-Hartman
2022-04-14 15:01 ` Ard Biesheuvel
2022-04-14 15:01 ` Ard Biesheuvel
2022-04-14 15:10 ` Ard Biesheuvel
2022-04-14 15:10 ` Ard Biesheuvel
2022-04-14 19:49 ` Catalin Marinas
2022-04-14 19:49 ` Catalin Marinas
2022-04-14 22:25 ` Linus Torvalds
2022-04-14 22:25 ` Linus Torvalds
2022-04-15 6:03 ` Ard Biesheuvel
2022-04-15 6:03 ` Ard Biesheuvel
2022-04-15 11:09 ` Arnd Bergmann
2022-04-15 11:09 ` Arnd Bergmann
2022-04-16 9:42 ` Catalin Marinas
2022-04-16 9:42 ` Catalin Marinas
2022-04-20 19:07 ` Catalin Marinas
2022-04-20 19:07 ` Catalin Marinas
2022-04-20 19:33 ` Linus Torvalds
2022-04-20 19:33 ` Linus Torvalds
2022-04-14 14:30 ` Ard Biesheuvel
2022-04-14 14:30 ` Ard Biesheuvel
2022-04-15 6:51 ` Herbert Xu
2022-04-15 6:51 ` Herbert Xu
2022-04-15 7:49 ` Ard Biesheuvel
2022-04-15 7:49 ` Ard Biesheuvel
2022-04-15 7:51 ` Herbert Xu
2022-04-15 7:51 ` Herbert Xu
2022-04-15 8:05 ` Ard Biesheuvel
2022-04-15 8:05 ` Ard Biesheuvel
2022-04-15 8:12 ` Herbert Xu
2022-04-15 8:12 ` Herbert Xu
2022-04-15 9:51 ` Ard Biesheuvel
2022-04-15 9:51 ` Ard Biesheuvel
2022-04-15 10:04 ` Ard Biesheuvel
2022-04-15 10:04 ` Ard Biesheuvel
2022-04-15 10:12 ` Herbert Xu
2022-04-15 10:12 ` Herbert Xu
2022-04-15 10:22 ` Ard Biesheuvel
2022-04-15 10:22 ` Ard Biesheuvel
2022-04-15 10:45 ` Herbert Xu
2022-04-15 10:45 ` Herbert Xu
2022-04-15 11:38 ` Ard Biesheuvel
2022-04-15 11:38 ` Ard Biesheuvel
2022-04-17 8:08 ` Herbert Xu
2022-04-17 8:08 ` Herbert Xu
2022-04-17 8:31 ` Catalin Marinas
2022-04-17 8:31 ` Catalin Marinas
2022-04-17 8:35 ` Herbert Xu
2022-04-17 8:35 ` Herbert Xu
2022-04-17 8:50 ` Catalin Marinas
2022-04-17 8:50 ` Catalin Marinas
2022-04-17 8:58 ` Herbert Xu
2022-04-17 8:58 ` Herbert Xu
2022-04-17 16:30 ` Catalin Marinas
2022-04-17 16:30 ` Catalin Marinas
2022-04-18 8:37 ` Herbert Xu
2022-04-18 8:37 ` Herbert Xu
2022-04-18 9:19 ` Catalin Marinas
2022-04-18 9:19 ` Catalin Marinas
2022-04-18 16:44 ` Catalin Marinas
2022-04-18 16:44 ` Catalin Marinas
2022-04-19 21:50 ` Ard Biesheuvel
2022-04-19 21:50 ` Ard Biesheuvel
2022-04-20 10:36 ` Catalin Marinas
2022-04-20 10:36 ` Catalin Marinas
2022-04-20 11:29 ` Arnd Bergmann
2022-04-20 11:29 ` Arnd Bergmann
2022-04-21 7:20 ` Christoph Hellwig
2022-04-21 7:20 ` Christoph Hellwig
2022-04-21 7:36 ` Arnd Bergmann
2022-04-21 7:36 ` Arnd Bergmann
2022-04-21 7:44 ` Christoph Hellwig
2022-04-21 7:44 ` Christoph Hellwig
2022-04-21 8:05 ` Ard Biesheuvel
2022-04-21 8:05 ` Ard Biesheuvel
2022-04-21 11:06 ` Catalin Marinas
2022-04-21 11:06 ` Catalin Marinas
2022-04-21 12:28 ` Arnd Bergmann
2022-04-21 12:28 ` Arnd Bergmann
2022-04-21 13:25 ` Catalin Marinas
2022-04-21 13:25 ` Catalin Marinas
2022-04-21 13:47 ` Arnd Bergmann
2022-04-21 13:47 ` Arnd Bergmann
2022-04-21 14:44 ` Catalin Marinas
2022-04-21 14:44 ` Catalin Marinas
2022-04-21 14:47 ` Arnd Bergmann
2022-04-21 14:47 ` Arnd Bergmann
2022-05-10 11:03 ` [RFC PATCH 0/7] crypto: Add helpers for allocating with DMA alignment Herbert Xu
2022-05-10 11:03 ` Herbert Xu
2022-05-10 11:07 ` [RFC PATCH 1/7] crypto: Prepare to move crypto_tfm_ctx Herbert Xu
2022-05-10 11:07 ` Herbert Xu
2022-05-10 11:07 ` [RFC PATCH 2/7] crypto: api - Add crypto_tfm_ctx_dma Herbert Xu
2022-05-10 11:07 ` Herbert Xu
2022-05-10 17:10 ` Catalin Marinas
2022-05-10 17:10 ` Catalin Marinas
2022-05-12 3:57 ` Herbert Xu
2022-05-12 3:57 ` Herbert Xu
2022-05-10 11:07 ` [RFC PATCH 3/7] crypto: aead - Add ctx helpers with DMA alignment Herbert Xu
2022-05-10 11:07 ` Herbert Xu
2022-05-10 11:07 ` [RFC PATCH 4/7] crypto: hash " Herbert Xu
2022-05-10 11:07 ` Herbert Xu
2022-05-10 11:07 ` [RFC PATCH 5/7] crypto: skcipher " Herbert Xu
2022-05-10 11:07 ` Herbert Xu
2022-05-10 11:07 ` [RFC PATCH 6/7] crypto: api - Increase MAX_ALGAPI_ALIGNMASK to 127 Herbert Xu
2022-05-10 11:07 ` Herbert Xu
2022-05-10 11:07 ` [RFC PATCH 7/7] crypto: caam - Explicitly request DMA alignment Herbert Xu
2022-05-10 11:07 ` Herbert Xu
2022-04-15 12:18 ` [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN Catalin Marinas
2022-04-15 12:18 ` Catalin Marinas
2022-04-15 12:25 ` Ard Biesheuvel
2022-04-15 12:25 ` Ard Biesheuvel
2022-04-15 9:51 ` Catalin Marinas [this message]
2022-04-15 9:51 ` Catalin Marinas
2022-04-15 12:31 ` Catalin Marinas
2022-04-15 12:31 ` Catalin Marinas
2022-04-17 8:11 ` Herbert Xu
2022-04-17 8:11 ` Herbert Xu
2022-04-17 8:38 ` Catalin Marinas
2022-04-17 8:38 ` Catalin Marinas
2022-04-17 8:43 ` Herbert Xu
2022-04-17 8:43 ` Herbert Xu
2022-04-17 16:29 ` Catalin Marinas
2022-04-17 16:29 ` Catalin Marinas
2022-07-15 22:23 ` Isaac Manjarres
2022-07-15 22:23 ` Isaac Manjarres
2022-07-16 3:25 ` Herbert Xu
2022-07-16 3:25 ` Herbert Xu
2022-07-18 17:53 ` Catalin Marinas
2022-07-18 17:53 ` Catalin Marinas
2022-09-21 0:47 ` Isaac Manjarres
2022-09-21 0:47 ` Isaac Manjarres
2022-09-30 18:32 ` Catalin Marinas
2022-09-30 18:32 ` Catalin Marinas
2022-09-30 19:35 ` Linus Torvalds
2022-09-30 19:35 ` Linus Torvalds
2022-10-01 22:29 ` Catalin Marinas
2022-10-01 22:29 ` Catalin Marinas
2022-10-02 17:00 ` Linus Torvalds
2022-10-02 17:00 ` Linus Torvalds
2022-10-02 22:08 ` Ard Biesheuvel
2022-10-02 22:08 ` Ard Biesheuvel
2022-10-02 22:24 ` Linus Torvalds
2022-10-02 22:24 ` Linus Torvalds
2022-10-03 17:39 ` Catalin Marinas
2022-10-03 17:39 ` Catalin Marinas
2022-10-12 17:45 ` Isaac Manjarres
2022-10-12 17:45 ` Isaac Manjarres
2022-10-13 16:57 ` Catalin Marinas
2022-10-13 16:57 ` Catalin Marinas
2022-10-13 18:58 ` Saravana Kannan
2022-10-13 18:58 ` Saravana Kannan
2022-10-14 16:25 ` Catalin Marinas
2022-10-14 16:25 ` Catalin Marinas
2022-10-14 20:23 ` Saravana Kannan
2022-10-14 20:23 ` Saravana Kannan
2022-10-14 20:44 ` Linus Torvalds
2022-10-14 20:44 ` Linus Torvalds
2022-10-16 21:37 ` Catalin Marinas
2022-10-16 21:37 ` Catalin Marinas
2022-04-12 10:20 ` Catalin Marinas
2022-04-12 10:20 ` Catalin Marinas
2022-04-07 6:14 ` Muchun Song
2022-04-07 6:14 ` Muchun Song
2022-04-07 9:25 ` Catalin Marinas
2022-04-07 9:25 ` Catalin Marinas
2022-04-07 10:00 ` Muchun Song
2022-04-07 10:00 ` Muchun Song
2022-04-07 11:06 ` Catalin Marinas
2022-04-07 11:06 ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 08/10] mm/slab: Allow dynamic kmalloc() minimum alignment Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-07 3:46 ` Hyeonggon Yoo
2022-04-07 3:46 ` Hyeonggon Yoo
2022-04-07 8:50 ` Catalin Marinas
2022-04-07 8:50 ` Catalin Marinas
2022-04-07 9:18 ` Hyeonggon Yoo
2022-04-07 9:18 ` Hyeonggon Yoo
2022-04-07 9:35 ` Catalin Marinas
2022-04-07 9:35 ` Catalin Marinas
2022-04-07 12:26 ` Hyeonggon Yoo
2022-04-07 12:26 ` Hyeonggon Yoo
2022-04-11 11:55 ` Hyeonggon Yoo
2022-04-11 11:55 ` Hyeonggon Yoo
2022-04-05 13:57 ` [PATCH 09/10] mm/slab: Simplify create_kmalloc_cache() args and make it static Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-06 5:35 ` kernel test robot
2022-04-06 8:57 ` Catalin Marinas
2022-04-06 8:57 ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 10/10] arm64: Enable dynamic kmalloc() minimum alignment Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-07 14:40 ` [PATCH 00/10] mm, arm64: Reduce ARCH_KMALLOC_MINALIGN below the cache line size Vlastimil Babka
2022-04-07 14:40 ` Vlastimil Babka
2022-04-07 17:48 ` Catalin Marinas
2022-04-07 17:48 ` Catalin Marinas
2022-04-08 14:37 ` Vlastimil Babka
2022-04-08 14:37 ` Vlastimil Babka
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