linux-kernel - Re: [git pull] iov

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]

Message-ID: <YTrJsrXPbu1jXKDZ@zeniv-ca.linux.org.uk>
Date:   Fri, 10 Sep 2021 02:57:54 +0000
From:   Al Viro <viro@...iv.linux.org.uk>
To:     Jens Axboe <axboe@...nel.dk>
Cc:     Linus Torvalds <torvalds@...ux-foundation.org>,
        Pavel Begunkov <asml.silence@...il.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-fsdevel <linux-fsdevel@...r.kernel.org>
Subject: Re: [git pull] iov_iter fixes

On Thu, Sep 09, 2021 at 03:19:56PM -0600, Jens Axboe wrote:

> Not sure how we'd do that, outside of stupid tricks like copy the
> iov_iter before we pass it down. But that's obviously not going to be
> very efficient. Hence we're left with having some way to reset/reexpand,
> even in the presence of someone having done truncate on it.

"Obviously" why, exactly?  It's not that large a structure; it's not
the optimal variant, but I'd like to see profiling data before assuming
that it'll cause noticable slowdowns.