Re: [regression] TCP_MD5SIG on established sockets

From: Joe Perches
Date: Tue Jun 30 2020 - 22:39:20 EST


On Tue, 2020-06-30 at 19:30 -0700, Eric Dumazet wrote:
> On Tue, Jun 30, 2020 at 7:23 PM Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
> > On Tue, Jun 30, 2020 at 07:17:46PM -0700, Eric Dumazet wrote:
> > > The main issue of the prior code was the double read of key->keylen in
> > > tcp_md5_hash_key(), not that few bytes could change under us.
> > >
> > > I used smp_rmb() to ease backports, since old kernels had no
> > > READ_ONCE()/WRITE_ONCE(), but ACCESS_ONCE() instead.
> >
> > If it's the double-read that you're protecting against, you should
> > just use barrier() and the comment should say so too.
>
> I made this clear in the changelog, do we want comments all over the places ?

Having to run git for every line of code isn't great.

Comments in code is better than comments in changelogs.