linux-kernel - Re: [PATCH v7 21/22] x86/boot: Move startup code out of _

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: <CAMj1kXEz89RyRCv94ubGcq3=fs27DaNNkJ8ZT46ifKNqu9+ixg@mail.gmail.com>
Date: Wed, 3 Sep 2025 11:20:54 +0200
From: Ard Biesheuvel <ardb@...nel.org>
To: Ard Biesheuvel <ardb+git@...gle.com>
Cc: linux-kernel@...r.kernel.org, linux-efi@...r.kernel.org, x86@...nel.org, 
	Borislav Petkov <bp@...en8.de>, Ingo Molnar <mingo@...nel.org>, 
	Kevin Loughlin <kevinloughlin@...gle.com>, Tom Lendacky <thomas.lendacky@....com>, 
	Josh Poimboeuf <jpoimboe@...nel.org>, Peter Zijlstra <peterz@...radead.org>, 
	Nikunj A Dadhania <nikunj@....com>
Subject: Re: [PATCH v7 21/22] x86/boot: Move startup code out of __head section

On Thu, 28 Aug 2025 at 12:23, Ard Biesheuvel <ardb+git@...gle.com> wrote:
>
> From: Ard Biesheuvel <ardb@...nel.org>
>
> Move startup code out of the __head section, now that this no longer has
> a special significance. Move everything into .text or .init.text as
> appropriate, so that startup code is not kept around unnecessarily.
>
> Signed-off-by: Ard Biesheuvel <ardb@...nel.org>
> ---
>  arch/x86/boot/compressed/sev.c      |  3 --
>  arch/x86/boot/startup/gdt_idt.c     |  4 +--
>  arch/x86/boot/startup/map_kernel.c  |  4 +--
>  arch/x86/boot/startup/sev-shared.c  | 36 ++++++++++----------
>  arch/x86/boot/startup/sev-startup.c | 14 ++++----
>  arch/x86/boot/startup/sme.c         | 26 +++++++-------
>  arch/x86/include/asm/init.h         |  6 ----
>  arch/x86/kernel/head_32.S           |  2 +-
>  arch/x86/kernel/head_64.S           |  2 +-
>  arch/x86/platform/pvh/head.S        |  2 +-
>  10 files changed, 45 insertions(+), 54 deletions(-)
>

As reported here [0], this patch needs the next hunk folded in to
avoid breaking CPU hotplug on i386

--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -136,6 +136,9 @@ SYM_CODE_END(startup_32)
  * If cpu hotplug is not supported then this code can go in init section
  * which will be freed later
  */
+#ifdef CONFIG_HOTPLUG_CPU
+       .text
+#endif
 SYM_FUNC_START(startup_32_smp)
        cld
        movl $(__BOOT_DS),%eax

[0] https://lore.kernel.org/all/202509022207.56fd97f4-lkp@intel.com/T/#u