From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Charlie Jenkins <charlie@rivosinc.com>,
Guenter Roeck <linux@roeck-us.net>,
David Laight <David.Laight@aculab.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Andrew Morton <akpm@linux-foundation.org>,
Helge Deller <deller@gmx.de>,
"James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
Parisc List <linux-parisc@vger.kernel.org>,
Arnd Bergmann <arnd@arndb.de>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Palmer Dabbelt <palmer@rivosinc.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Russell King <linux@armlinux.org.uk>
Subject: Re: [PATCH v10] lib: checksum: Use aligned accesses for ip_fast_csum and csum_ipv6_magic tests
Date: Mon, 26 Feb 2024 11:34:51 +0000 [thread overview]
Message-ID: <7ae930a7-3b10-4470-94ee-89cb650b3349@csgroup.eu> (raw)
In-Reply-To: <20240223-fix_sparse_errors_checksum_tests-v10-1-b6a45914b7d8@rivosinc.com>
Le 23/02/2024 à 23:11, Charlie Jenkins a écrit :
> The test cases for ip_fast_csum and csum_ipv6_magic were not properly
> aligning the IP header, which were causing failures on architectures
> that do not support misaligned accesses like some ARM platforms. To
> solve this, align the data along (14 + NET_IP_ALIGN) bytes which is the
> standard alignment of an IP header and must be supported by the
> architecture.
I'm still wondering what we are really trying to fix here.
All other tests are explicitely testing that it works with any alignment.
Shouldn't ip_fast_csum() and csum_ipv6_magic() work for any alignment as
well ? I would expect it, I see no comment in arm code which explicits
that assumption around those functions.
Isn't the problem only the following line, because csum_offset is
unaligned ?
csum = *(__wsum *)(random_buf + i + csum_offset);
Otherwise, if there really is an alignment issue for the IPv6 source or
destination address, isn't it enough to perform a 32 bits alignment ?
I guess we should involve ARM people in this discussion.
Christophe
next prev parent reply other threads:[~2024-02-26 11:34 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-23 22:11 [PATCH v10] lib: checksum: Use aligned accesses for ip_fast_csum and csum_ipv6_magic tests Charlie Jenkins
2024-02-25 15:58 ` Guenter Roeck
2024-02-26 11:34 ` Christophe Leroy [this message]
2024-02-26 11:47 ` Russell King (Oracle)
2024-02-26 11:57 ` Christophe Leroy
2024-02-26 12:03 ` Russell King (Oracle)
2024-02-26 16:44 ` Guenter Roeck
2024-02-26 17:50 ` Russell King (Oracle)
2024-02-26 18:35 ` Charlie Jenkins
2024-02-26 19:06 ` Russell King (Oracle)
2024-02-26 19:19 ` Charlie Jenkins
2024-02-26 22:33 ` David Laight
2024-02-26 23:17 ` Charlie Jenkins
2024-02-26 23:48 ` Guenter Roeck
2024-02-27 6:47 ` Christophe Leroy
2024-02-27 10:28 ` Russell King (Oracle)
2024-02-27 11:32 ` Christophe Leroy
2024-02-27 17:54 ` Charlie Jenkins
2024-02-27 18:11 ` Christophe Leroy
2024-02-27 18:21 ` Charlie Jenkins
2024-02-27 18:35 ` Christophe Leroy
2024-02-27 19:04 ` Charlie Jenkins
2024-02-27 19:31 ` Guenter Roeck
2024-02-27 22:44 ` David Laight
2024-02-28 5:19 ` Guenter Roeck
2024-02-28 0:24 ` Charlie Jenkins
2024-02-28 0:21 ` Charlie Jenkins
2024-02-28 7:25 ` Christophe Leroy
2024-02-28 7:59 ` Guenter Roeck
2024-02-28 10:15 ` Geert Uytterhoeven
2024-02-28 15:40 ` Guenter Roeck
2024-02-29 8:07 ` David Gow
2024-02-29 19:38 ` Charlie Jenkins
2024-02-29 20:22 ` Guenter Roeck
2024-03-01 7:00 ` Christophe Leroy
2024-03-01 6:46 ` Christophe Leroy
2024-03-01 16:24 ` Guenter Roeck
2024-03-01 20:47 ` Guenter Roeck
2024-02-27 11:17 ` Geert Uytterhoeven
2024-02-27 17:55 ` Charlie Jenkins
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