linux-kernel - Re: [RFC PATCH v9 01/27] Documentation/x86: Add CET description

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: <c06073a2-6858-d5dc-d74b-ef2568bd9423@intel.com>
Date:   Mon, 9 Mar 2020 16:20:57 -0700
From:   Dave Hansen <dave.hansen@...el.com>
To:     "H.J. Lu" <hjl.tools@...il.com>
Cc:     Andy Lutomirski <luto@...capital.net>,
        Yu-cheng Yu <yu-cheng.yu@...el.com>,
        the arch/x86 maintainers <x86@...nel.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        LKML <linux-kernel@...r.kernel.org>, linux-doc@...r.kernel.org,
        Linux-MM <linux-mm@...ck.org>,
        linux-arch <linux-arch@...r.kernel.org>,
        Linux API <linux-api@...r.kernel.org>,
        Arnd Bergmann <arnd@...db.de>,
        Andy Lutomirski <luto@...nel.org>,
        Balbir Singh <bsingharora@...il.com>,
        Borislav Petkov <bp@...en8.de>,
        Cyrill Gorcunov <gorcunov@...il.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Eugene Syromiatnikov <esyr@...hat.com>,
        Florian Weimer <fweimer@...hat.com>,
        Jann Horn <jannh@...gle.com>, Jonathan Corbet <corbet@....net>,
        Kees Cook <keescook@...omium.org>,
        Mike Kravetz <mike.kravetz@...cle.com>,
        Nadav Amit <nadav.amit@...il.com>,
        Oleg Nesterov <oleg@...hat.com>, Pavel Machek <pavel@....cz>,
        Peter Zijlstra <peterz@...radead.org>,
        Randy Dunlap <rdunlap@...radead.org>,
        "Ravi V. Shankar" <ravi.v.shankar@...el.com>,
        Vedvyas Shanbhogue <vedvyas.shanbhogue@...el.com>,
        Dave Martin <Dave.Martin@....com>, x86-patch-review@...el.com
Subject: Re: [RFC PATCH v9 01/27] Documentation/x86: Add CET description

On 3/9/20 4:11 PM, H.J. Lu wrote:
> A threaded application is loaded from disk.  The object file on disk is
> either CET enabled or not CET enabled.

Huh.  Are you saying that all instructions executed on userspace on
Linux come off of object files on the disk?  That's an interesting
assertion.  You might want to go take a look at the processes on your
systems.  Here's my browser for example:

# for p in $(ps aux | grep chromium | awk '{print $2}' ); do cat
/proc/$p/maps; done | grep ' r-xp 00000000 00:00 0'
...
202f00082000-202f000bf000 r-xp 00000000 00:00 0
202f000c2000-202f000c3000 r-xp 00000000 00:00 0
202f00102000-202f00103000 r-xp 00000000 00:00 0
202f00142000-202f00143000 r-xp 00000000 00:00 0
202f00182000-202f001bf000 r-xp 00000000 00:00 0

Lots of funny looking memory areas which are anonymous and executable!
Those didn't come off the disk.  Same thing in firefox.  Weird.  Any
idea what those are?

One guess: https://en.wikipedia.org/wiki/Just-in-time_compilation