linux-kernel - Re: [PATCH v2 00/14] efi/gop: Refactoring + mode-setting feature

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]

Date:   Thu, 26 Mar 2020 11:41:00 +0100
From:   Ard Biesheuvel <ardb@...nel.org>
To:     Arvind Sankar <nivedita@...m.mit.edu>
Cc:     Hans de Goede <hdegoede@...hat.com>,
        linux-efi <linux-efi@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 00/14] efi/gop: Refactoring + mode-setting feature

On Thu, 26 Mar 2020 at 00:36, Ard Biesheuvel <ardb@...nel.org> wrote:
>
> On Wed, 25 Mar 2020 at 23:10, Arvind Sankar <nivedita@...m.mit.edu> wrote:
> >
> > On Wed, Mar 25, 2020 at 05:41:43PM +0100, Ard Biesheuvel wrote:
> > > On Fri, 20 Mar 2020 at 03:00, Arvind Sankar <nivedita@...m.mit.edu> wrote:
> > > >
> > > > This series is against tip:efi/core.
> > > >
> > > > Patches 1-9 are small cleanups and refactoring of the code in
> > > > libstub/gop.c.
> > > >
> > > > The rest of the patches add the ability to use a command-line option to
> > > > switch the gop's display mode.
> > > >
> > > > The options supported are:
> > > > video=efifb:mode=n
> > > >         Choose a specific mode number
> > > > video=efifb:<xres>x<yres>[-(rgb|bgr|<bpp>)]
> > > >         Specify mode by resolution and optionally color depth
> > > > video=efifb:auto
> > > >         Let the EFI stub choose the highest resolution mode available.
> > > >
> > > > The mode-setting additions increase code size of gop.o by about 3k on
> > > > x86-64 with EFI_MIXED enabled.
> > > >
> > > > Changes in v2 (HT lkp@...el.com):
> > > > - Fix __efistub_global attribute to be after the variable.
> > > >   (NB: bunch of other places should ideally be fixed, those I guess
> > > >   don't matter as they are scalars?)
> > > > - Silence -Wmaybe-uninitialized warning in set_mode function.
> > > >
> > >
> > > These look good to me. The only question I have is whether it would be
> > > possible to use the existing next_arg() and parse_option_str()
> > > functions to replace some of the open code parsing that goes on in
> > > patches 11 - 14.
> > >
> >
> > I don't think so -- next_arg is for parsing space-separated param=value
> > pairs, so efi_parse_options can use it, but it doesn't work for the
> > comma-separated options we'll have within the value.
> >
> > parse_option_str would only work for the "auto" option, but it scans the
> > entire option string and just returns whether it was there or not, so it
> > wouldn't be too useful either, since we have to check for the other
> > possibilities anyway.
> >
> > It would be nice to have a more generic library for cmdline parsing,
> > there are a lot of places that have to open-code option parsing like
> > this.
> >

OK, I have queued these up now in the EFI next branch, but this will
obviously have to wait for v5.8

Thanks