netdev - Re: What is the purpose of dev->gflags?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 11 Apr 2022 18:10:49 +0200
From:   Nicolas Dichtel <nicolas.dichtel@...nd.com>
To:     Vladimir Oltean <olteanv@...il.com>
Cc:     Jakub Kicinski <kuba@...nel.org>, netdev@...r.kernel.org,
        "David S. Miller" <davem@...emloft.net>,
        Paolo Abeni <pabeni@...hat.com>
Subject: Re: What is the purpose of dev->gflags?


Le 11/04/2022 à 17:49, Vladimir Oltean a écrit :
> On Mon, Apr 11, 2022 at 05:43:01PM +0200, Nicolas Dichtel wrote:
>>
>> Le 11/04/2022 à 17:33, Vladimir Oltean a écrit :
>> [snip]
>>> Would you agree that the __dev_set_allmulti() -> __dev_notify_flags()
>>> call path is dead code? If it is, is there any problem it should be
>>> addressing which it isn't, or can we just delete it?
>> I probably miss your point, why is it dead code?
> 
> Because __dev_set_allmulti() doesn't update dev->gflags, it means
> dev->gflags == old_gflags. In turn, it means dev->gflags ^ old_gflags,
> passed to "gchanges" of __dev_notify_flags(), is 0.
I didn't take any assumptions on dev->gflags because two functions are called
with dev as parameter (dev_change_rx_flags() and dev_set_rx_mode()).
Even if __dev_notify_flags() is called with 0 for the last arg, it calls
notifiers. Thus, this is not "dead code".