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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed, 28 Apr 2021 10:46:35 -0700
Message-ID: <CAHk-=wibrw+PnBiQbkGy+5p4GpkPwmmodw-beODikL-tiz0dFQ@mail.gmail.com>
Subject: Re: [PATCH] proc: Use seq_read_iter where possible
To:     Christoph Hellwig <hch@lst.de>
Cc:     Arusekk <arek_koz@o2.pl>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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On Wed, Apr 28, 2021 at 6:03 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Unless Linus changed his mind just patching the file you care about for
> now seems like the best idea.

I'm ok with expanding splice() use, but I do want it to be on a
case-by-case basis and with comments about what actually used splice()
in the odd circumstances.

Our splice infrastructure is probably a lot safer than it used to be
now that set_fs() is gone, but splice() on odd files does remain
historically a source of not just bugs, but bugs that were security
issues.

So it's mainly a "once bitten, twice shy" thing for me, which is why
I'm more than happy to extend splice(), but want to do so in a very
careful and controlled - and documented - manner, rather than the old
situation where "pretty much everything can do splice, whether it
actually works or not".

                 Linus