From: Al Viro <viro@zeniv.linux.org.uk>
To: David Laight <David.Laight@aculab.com>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
gus Gusenleitner Klaus <gus@keba.com>,
Al Viro <viro@ftp.linux.org.uk>,
Thomas Gleixner <tglx@linutronix.de>,
lkml <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>, "bp@alien8.de" <bp@alien8.de>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
"x86@kernel.org" <x86@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
"dsahern@kernel.org" <dsahern@kernel.org>,
"kuba@kernel.org" <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>,
Eric Dumazet <edumazet@google.com>
Subject: Re: [RFC][PATCHES v2] checksum stuff
Date: Wed, 6 Dec 2023 22:43:59 +0000 [thread overview]
Message-ID: <20231206224359.GR1674809@ZenIV> (raw)
In-Reply-To: <602ab11ffa2c4cc49bb9ecae2f0540b0@AcuMS.aculab.com>
On Wed, Dec 06, 2023 at 11:10:45AM +0000, David Laight wrote:
> Do we?
> I've not seen any justification for this at all.
> IIRC the ICMPv4 reply code needs the checksum function return 0xffff
> for all-zero input.
>
> So the correct and simple fix is to initialise the sum to 0xffff
> in the checksum function.
You do realize that ICMPv4 reply code is not the only user of those,
right? Sure, we can special-case it there. And audit the entire
call tree, proving that no other call chains need the same.
Care to post the analysis? I have the beginnings of that and it's already
long and convoluted and touches far too many places, all of which will
have to be watched indefinitely, so that changes in there don't introduce
new breakage.
I could be wrong. About many things, including the depth of your
aversion to RTFS. But frankly, until that analysis shows up somewhere,
I'm going to ignore your usual handwaving.
next prev parent reply other threads:[~2023-12-06 22:44 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <VI1PR0702MB3840EB26EF2A1A35BFEA53BFD9D5A@VI1PR0702MB3840.eurprd07.prod.outlook.com>
[not found] ` <20231018154205.GT800259@ZenIV>
[not found] ` <VI1PR0702MB3840F2D594B9681BF2E0CD81D9D4A@VI1PR0702MB3840.eurprd07.prod.outlook.com>
[not found] ` <20231019050250.GV800259@ZenIV>
[not found] ` <20231019061427.GW800259@ZenIV>
[not found] ` <20231019063925.GX800259@ZenIV>
[not found] ` <CANn89iJre=VQ6J=UuD0d2J5t=kXr2b9Dk9b=SwzPX1CM+ph60A@mail.gmail.com>
[not found] ` <20231019080615.GY800259@ZenIV>
[not found] ` <20231021071525.GA789610@ZenIV>
[not found] ` <20231021222203.GA800259@ZenIV>
2023-10-22 19:40 ` [RFC][PATCH] fix csum_and_copy_..._user() idiocy. Re: AW: [PATCH] amd64: Fix csum_partial_copy_generic() Al Viro
2023-10-22 19:46 ` Al Viro
2023-10-23 10:37 ` Thomas Gleixner
2023-10-24 4:26 ` Al Viro
2023-10-24 12:31 ` Thomas Gleixner
2023-10-23 14:44 ` David Laight
2023-10-24 3:53 ` Al Viro
2023-12-05 2:21 ` [RFC][PATCHES v2] checksum stuff Al Viro
2023-12-05 2:23 ` [PATCH v2 01/18] make net/checksum.h self-contained Al Viro
2023-12-05 2:23 ` [PATCH v2 1/9] reiserfs: Avoid touching renamed directory if parent does not change Al Viro
2023-12-05 2:23 ` [PATCH v2 02/18] get rid of asm/checksum.h includes outside of include/net/checksum.h and arch Al Viro
2023-12-05 2:23 ` [PATCH v2 2/9] ocfs2: Avoid touching renamed directory if parent does not change Al Viro
2023-12-05 2:23 ` [PATCH v2 03/18] make net/checksum.h the sole user of asm/checksum.h Al Viro
2023-12-05 2:23 ` [PATCH v2 3/9] udf_rename(): only access the child content on cross-directory rename Al Viro
2023-12-05 2:23 ` [PATCH v2 4/9] ext2: Avoid reading renamed directory if parent does not change Al Viro
2023-12-05 2:23 ` [PATCH v2 04/18] Fix the csum_and_copy_..._user() idiocy Al Viro
2023-12-05 2:24 ` [PATCH v2 05/18] bits missing from csum_and_copy_{from,to}_user() unexporting Al Viro
2023-12-05 2:24 ` [PATCH v2 5/9] ext4: don't access the source subdirectory content on same-directory rename Al Viro
2023-12-05 2:24 ` [PATCH v2 06/18] consolidate csum_tcpudp_magic(), take default variant into net/checksum.h Al Viro
2023-12-05 2:24 ` [PATCH v2 6/9] f2fs: Avoid reading renamed directory if parent does not change Al Viro
2023-12-05 2:24 ` [PATCH v2 07/18] consolidate default ip_compute_csum() Al Viro
2023-12-05 2:24 ` [PATCH v2 7/9] rename(): fix the locking of subdirectories Al Viro
2023-12-05 2:24 ` [PATCH v2 08/18] alpha: pull asm-generic/checksum.h Al Viro
2023-12-05 2:24 ` [PATCH v2 8/9] kill lock_two_inodes() Al Viro
2023-12-05 2:24 ` [PATCH v2 09/18] mips: pull include of asm-generic/checksum.h out of #if Al Viro
2023-12-05 2:24 ` [PATCH v2 9/9] rename(): avoid a deadlock in the case of parents having no common ancestor Al Viro
2023-12-05 2:24 ` [PATCH v2 10/18] nios2: pull asm-generic/checksum.h Al Viro
2023-12-05 2:24 ` [PATCH v2 11/18] x86: merge csum_fold() for 32bit and 64bit Al Viro
2023-12-05 2:24 ` [PATCH v2 12/18] x86: merge ip_fast_csum() " Al Viro
2023-12-05 2:24 ` [PATCH v2 13/18] x86: merge csum_tcpudp_nofold() " Al Viro
2023-12-05 2:24 ` [PATCH v2 14/18] amd64: saner handling of odd address in csum_partial() Al Viro
2023-12-05 2:24 ` [PATCH v2 15/18] x86: optimized csum_add() is the same for 32bit and 64bit Al Viro
2023-12-05 2:24 ` [PATCH v2 16/18] x86: lift the extern for csum_partial() into checksum.h Al Viro
2023-12-05 2:24 ` [PATCH v2 17/18] x86_64: move csum_ipv6_magic() from csum-wrappers_64.c to csum-partial_64.c Al Viro
2023-12-05 2:24 ` [PATCH v2 18/18] uml/x86: use normal x86 checksum.h Al Viro
2024-01-03 22:02 ` Richard Weinberger
2023-12-05 2:27 ` [RFC][PATCHES v2] checksum stuff Al Viro
2023-12-06 11:10 ` David Laight
2023-12-06 22:43 ` Al Viro [this message]
2023-12-07 9:58 ` David Laight
2023-12-08 12:04 ` David Laight
2023-12-08 14:17 ` Al Viro
2023-12-08 15:29 ` Al Viro
2023-12-08 15:56 ` David Laight
2023-12-08 18:35 ` Al Viro
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