linux-kernel - RE: [PATCH V4 3/3] x86/efi: Introduce EFI_PAGE_FAULT

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: <FFF73D592F13FD46B8700F0A279B802F485BA620@ORSMSX114.amr.corp.intel.com>
Date:   Fri, 7 Sep 2018 19:08:27 +0000
From:   "Prakhya, Sai Praneeth" <sai.praneeth.prakhya@...el.com>
To:     Bhupesh Sharma <bhsharma@...hat.com>
CC:     "linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "x86@...nel.org" <x86@...nel.org>,
        "Neri, Ricardo" <ricardo.neri@...el.com>,
        "matt@...eblueprint.co.uk" <matt@...eblueprint.co.uk>,
        Al Stone <astone@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Ingo Molnar <mingo@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        "Peter Zijlstra" <peterz@...radead.org>
Subject: RE: [PATCH V4 3/3] x86/efi: Introduce EFI_PAGE_FAULT_HANDLER

> > > Why make this optional?
> >
> > I made it as a config option in RFC because the page fault handler was
> > complicated and touching many parts (it had lots of code change and I
> > didn't want to break any existing functionality). Now that it's
> > simple, I don't think we need the config option.
> >
> > Without efi page fault handler, any page fault caused by firmware
> > should panic kernel but with this patch I think we are just improving existing
> condition (ideally).
> >
> > So, if Thomas, Ingo, Andy, Ard and Boris are ok.. I will make it as
> > default (i.e. without config).
> >
> > Regards,
> > Sai
> >
> Also, some distributions already have specific ways to handle buggy firmwares
> which can be at times dependent on the underlying hardware and the firmware
> versions.
> 
> I would suggest that we enable this under a CONFIG for the first round and once
> it is tested with wider variety of x86 machines which have buggy or orphaned
> firmware and linux (and reboot) works fine with them, we can drop the CONFIG
> option in future and enable this by default.

Sounds fair to me, but, I would like to wait for someone experienced to make the final call.

Regards,
Sai