Re: [PATCH v4 RESEND net-next] net: socket: use BIT() for MSG_*

From: Guenter Roeck <linux@roeck-us.net>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: "menglong8.dong@gmail.com" <menglong8.dong@gmail.com>,
	"kuba@kernel.org" <kuba@kernel.org>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"axboe@kernel.dk" <axboe@kernel.dk>,
	"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
	"herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>,
	"dong.menglong@zte.com.cn" <dong.menglong@zte.com.cn>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH v4 RESEND net-next] net: socket: use BIT() for MSG_*
Date: Tue, 16 Mar 2021 16:54:46 -0700	[thread overview]
Message-ID: <3e744033-d73b-8bec-5117-4b85fa127351@roeck-us.net> (raw)
In-Reply-To: <CAHp75VdE3fkCjb53vBso5uJX9aEFtAOAdh5NVOSbK0YR64+jOg@mail.gmail.com>

On 3/16/21 4:02 PM, Andy Shevchenko wrote:
> 
> 
> On Wednesday, March 17, 2021, Guenter Roeck <linux@roeck-us.net <mailto:linux@roeck-us.net>> wrote:
> 
>     Hi,
> 
>     On Tue, Mar 09, 2021 at 05:51:35PM -0800, menglong8.dong@gmail.com <mailto:menglong8.dong@gmail.com> wrote:
>     > From: Menglong Dong <dong.menglong@zte.com.cn <mailto:dong.menglong@zte.com.cn>>
>     >
>     > The bit mask for MSG_* seems a little confused here. Replace it
>     > with BIT() to make it clear to understand.
>     >
>     > Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn <mailto:dong.menglong@zte.com.cn>>
> 
>     I must admit that I am a bit puzzled,
> 
> 
> I have checked the values and don’t see a problem. So, the only difference is the type int vs. unsigned long. I think this simply reveals an issue somewhere in the code.
>  

I am currently trying to "bisect" the individual bits. We'll see if I can find
the culprit(s).

Guenter

> 
> 
>      but with this patch in the tree
>     (in next-20210316) several of my qemu network interface tests fail
>     to get an IP address. So far I have only seen this with mips64
>     tests, but that may be because I only started running those tests
>     on various architectures.
> 
>     The tests do nothing special: With CONFIG_IP_PNP_DHCP=n, run udhcpc
>     in qemu to get an IP address. With this patch in place, udhcpc fails.
>     With this patch reverted, udhcpc gets the IP address as expected.
>     The error reported by udhcpc is:
> 
>     udhcpc: sending discover
>     udhcpc: read error: Invalid argument, reopening socket
> 
>     Reverting this patch fixes the problem.
> 
>     Guenter
> 
>     ---
>     bisect log:
> 
>     # bad: [0f4b0bb396f6f424a7b074d00cb71f5966edcb8a] Add linux-next specific files for 20210316
>     # good: [1e28eed17697bcf343c6743f0028cc3b5dd88bf0] Linux 5.12-rc3
>     git bisect start 'HEAD' 'v5.12-rc3'
>     # bad: [edd84c42baeffe66740143a04f24588fded94241] Merge remote-tracking branch 'drm-misc/for-linux-next'
>     git bisect bad edd84c42baeffe66740143a04f24588fded94241
>     # good: [a76f62d56da82bee1a4c35dd6375a8fdd57eca4e] Merge remote-tracking branch 'cel/for-next'
>     git bisect good a76f62d56da82bee1a4c35dd6375a8fdd57eca4e
>     # good: [e2924c67bae0cc15ca64dbe1ed791c96eed6d149] Merge remote-tracking branch 'rdma/for-next'
>     git bisect good e2924c67bae0cc15ca64dbe1ed791c96eed6d149
>     # bad: [a8f9952d218d816ff1a13c9385edd821a8da527d] selftests: fib_nexthops: List each test case in a different line
>     git bisect bad a8f9952d218d816ff1a13c9385edd821a8da527d
>     # bad: [4734a750f4674631ab9896189810b57700597aa7] mlxsw: Adjust some MFDE fields shift and size to fw implementation
>     git bisect bad 4734a750f4674631ab9896189810b57700597aa7
>     # good: [32e76b187a90de5809d68c2ef3e3964176dacaf0] bpf: Document BPF_PROG_ATTACH syscall command
>     git bisect good 32e76b187a90de5809d68c2ef3e3964176dacaf0
>     # good: [ee75aef23afe6e88497151c127c13ed69f41aaa2] bpf, xdp: Restructure redirect actions
>     git bisect good ee75aef23afe6e88497151c127c13ed69f41aaa2
>     # bad: [90d181ca488f466904ea59dd5c836f766b69c71b] net: rose: Fix fall-through warnings for Clang
>     git bisect bad 90d181ca488f466904ea59dd5c836f766b69c71b
>     # bad: [537a0c5c4218329990dc8973068f3bfe5c882623] net: fddi: skfp: smt: Replace one-element array with flexible-array member
>     git bisect bad 537a0c5c4218329990dc8973068f3bfe5c882623
>     # bad: [97c2c69e1926260c78c7f1c0b2c987934f1dc7a1] virtio-net: support XDP when not more queues
>     git bisect bad 97c2c69e1926260c78c7f1c0b2c987934f1dc7a1
>     # good: [c1acda9807e2bbe1d2026b44f37d959d6d8266c8] Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next <http://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next>
>     git bisect good c1acda9807e2bbe1d2026b44f37d959d6d8266c8
>     # bad: [0bb3262c0248d44aea3be31076f44beb82a7b120] net: socket: use BIT() for MSG_*
>     git bisect bad 0bb3262c0248d44aea3be31076f44beb82a7b120
>     # first bad commit: [0bb3262c0248d44aea3be31076f44beb82a7b120] net: socket: use BIT() for MSG_*
> 
> 
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 