linux-kernel - Re: [PATCH v3 3/7] x86/boot: Move the early GDT/IDT setup code into startup/

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: <CAMj1kXHPg7NxFwyT6jNp5FunnGbWRW7Kd2FG5UPntLb-sxB03Q@mail.gmail.com>
Date: Wed, 9 Apr 2025 13:42:37 +0200
From: Ard Biesheuvel <ardb@...nel.org>
To: Ingo Molnar <mingo@...nel.org>
Cc: Ard Biesheuvel <ardb+git@...gle.com>, linux-efi@...r.kernel.org, x86@...nel.org, 
	linux-kernel@...r.kernel.org, Tom Lendacky <thomas.lendacky@....com>, 
	Dionna Amalie Glaze <dionnaglaze@...gle.com>, Kevin Loughlin <kevinloughlin@...gle.com>
Subject: Re: [PATCH v3 3/7] x86/boot: Move the early GDT/IDT setup code into startup/

On Wed, 9 Apr 2025 at 12:07, Ingo Molnar <mingo@...nel.org> wrote:
>
>
> * Ingo Molnar <mingo@...nel.org> wrote:
>
> >
> > * Ard Biesheuvel <ardb+git@...gle.com> wrote:
> >
> > > From: Ard Biesheuvel <ardb@...nel.org>
> > >
> > > Move the early GDT/IDT setup code that runs long before the kernel
> > > virtual mapping is up into arch/x86/boot/startup/, and build it in a way
> > > that ensures that the code tolerates being called from the 1:1 mapping
> > > of memory. The code itself is left unchanged by this patch.
> > >
> > > Also tweak the sed symbol matching pattern in the decompressor to match
> > > on lower case 't' or 'b', as these will be emitted by Clang for symbols
> > > with hidden linkage.
> > >
> > > Signed-off-by: Ard Biesheuvel <ardb@...nel.org>
> > > ---
> > >  arch/x86/boot/compressed/Makefile |  2 +-
> > >  arch/x86/boot/startup/Makefile    | 15 ++++
> > >  arch/x86/boot/startup/gdt_idt.c   | 83 ++++++++++++++++++++
> > >  arch/x86/kernel/head64.c          | 73 -----------------
> > >  4 files changed, 99 insertions(+), 74 deletions(-)
> >
> > This causes the following build failure on x86-64-defconfig:
> >
> >    arch/x86/boot/startup/gdt_idt.c:67:55: error: cast to generic address space pointer from disjoint ‘__seg_gs’ address space pointer [-Werror]
>
> Caused by the previous patch:
>
>   x86/asm: Make rip_rel_ptr() usable from fPIC code
>

Oops, sorry about that. I saw that error and thought I had fixed it
with the (__force void*) cast.