linux-kernel - Re: syscall_get_error() && TS

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: <CA+55aFyrmc0YMxjNp_L=zPQBME6LnB3rBG9SsdF+_vVA5Ey_LQ@mail.gmail.com>
Date:   Wed, 29 Mar 2017 11:56:55 -0700
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     Oleg Nesterov <oleg@...hat.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Andy Lutomirski <luto@...nel.org>,
        Denys Vlasenko <dvlasenk@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
        Jan Kratochvil <jan.kratochvil@...hat.com>,
        Pedro Alves <palves@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        "the arch/x86 maintainers" <x86@...nel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: syscall_get_error() && TS_ checks

On Wed, Mar 29, 2017 at 11:50 AM, Oleg Nesterov <oleg@...hat.com> wrote:
>
> Again, afaics we only need these compat checks because regs->ax could be
> changed by 32-bit debugger without sign-extension.

You don't explain how you were planning on *fixing* that code. You
know why it exists, but then you just say "let's remove it", without
any explanation of what you'd replace it with.

If your suggestion is just that "let's remove it, breaking the known
reason it's there", I really really don't see the upside.

It may be hacky, but it *works*. You seem to be advocating replacing
it with something simpler - "cleaner, but broken".

I really don't see the point of "cleaner, but broken".

The fact is, reality is not "clean". But reality trumps :I wish" and
"make-believe" every single time.

         Linus