Messages in this thread | | | From | Christophe Leroy <> | 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 |
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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
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