linux-kernel - Re: [RFC PATCH 5/6] x86/alternatives: use temporary mm for text poking

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: <17f2c74c-93fb-5ec8-4022-bd433fe0e429@intel.com>
Date:   Wed, 29 Aug 2018 09:37:13 -0700
From:   Dave Hansen <dave.hansen@...el.com>
To:     Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>
Cc:     Nadav Amit <namit@...are.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        LKML <linux-kernel@...r.kernel.org>,
        Ingo Molnar <mingo@...hat.com>, X86 ML <x86@...nel.org>,
        Arnd Bergmann <arnd@...db.de>,
        linux-arch <linux-arch@...r.kernel.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Kees Cook <keescook@...omium.org>
Subject: Re: [RFC PATCH 5/6] x86/alternatives: use temporary mm for text
 poking

On 08/29/2018 09:32 AM, Andy Lutomirski wrote:
> It's plausible that there are workloads where the current code is
> faster, such as where we're munmapping a single page via syscall and
> we'd prefer to only flush that one TLB entry even if the flush
> operation is slower as a result.

Yeah, I don't specifically remember testing it.  But, I know I wanted to
avoid throwing away thousands of TLB entries when we only want to rid
ourselves of one.