linux-kernel - Re: [PATCH v2 4/6] powerpc: use common ptrace_syscall_enter hook to handle _TIF_SYSCALL

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: <20190318173341.GD23521@redhat.com>
Date:   Mon, 18 Mar 2019 18:33:41 +0100
From:   Oleg Nesterov <oleg@...hat.com>
To:     Sudeep Holla <sudeep.holla@....com>
Cc:     x86@...nel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        Richard Weinberger <richard@....at>, jdike@...toit.com,
        Steve Capper <Steve.Capper@....com>,
        Haibo Xu <haibo.xu@....com>, Bin Lu <bin.lu@....com>,
        Andy Lutomirski <luto@...nel.org>
Subject: Re: [PATCH v2 4/6] powerpc: use common ptrace_syscall_enter hook to
 handle _TIF_SYSCALL_EMU

On 03/18, Sudeep Holla wrote:
>
> On Mon, Mar 18, 2019 at 06:20:24PM +0100, Oleg Nesterov wrote:
> >
> > Again, to me this patch just makes the code look worse. Honestly, I don't
> > think that the new (badly named) ptrace_syscall_enter() hook makes any sense.
> >
>
> Worse because we end up reading current_thread_info->flags twice ?

Mostly because in my opinion ptrace_syscall_enter() buys nothing but makes
the caller's code less readable/understandable.

Sure, this is subjective.

Oleg.