Re: [RFC PATCH 20/56] x86/bugs: Move bugs.c logic out of .init section

Brendan Jackman
2025-10-16T14:33:36Z

On Thu Oct 16, 2025 at 1:46 PM UTC, David Kaplan wrote:
> [AMD Official Use Only - AMD Internal Distribution Only]
>
>> -----Original Message-----
>> From: Brendan Jackman <jackmanb@google.com>
>> Sent: Thursday, October 16, 2025 7:32 AM
>> To: Kaplan, David <David.Kaplan@amd.com>; Thomas Gleixner
>> <tglx@linutronix.de>; Borislav Petkov <bp@alien8.de>; Peter Zijlstra
>> <peterz@infradead.org>; Josh Poimboeuf <jpoimboe@kernel.org>; Pawan Gupta
>> <pawan.kumar.gupta@linux.intel.com>; Ingo Molnar <mingo@redhat.com>; Dave
>> Hansen <dave.hansen@linux.intel.com>; x86@kernel.org; H . Peter Anvin
>> <hpa@zytor.com>
>> Cc: Alexander Graf <graf@amazon.com>; Boris Ostrovsky
>> <boris.ostrovsky@oracle.com>; linux-kernel@vger.kernel.org
>> Subject: Re: [RFC PATCH 20/56] x86/bugs: Move bugs.c logic out of .init section
>>
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>>
>> On Mon Oct 13, 2025 at 2:34 PM UTC, David Kaplan wrote:
>> > If dynamic mitigations are supported, all the mitigation selection
>> > functions and mitigation choices may change at runtime. Therefore, none of
>> > the functions may exist in .init and the data must not be read-only.
>>
>> I suppose we should have something akin to
>> __meminit/__init_or_module/__net_init here (like __init, but conditional
>> on Kconfig), so that users with CONFIG_DYNAMIC_MITIGATIONS=n can still
>> get the RAM back?
>
> Yeah, that's an option (maybe like __bugs_init). Initial feedback I got was just to remove them from .init since they're now sometimes used later, but we could create a separate attribute tag. Similar for the __ro_after_init ones.

OK, if you'd already thought of it and people didn't want the
maintenance burden, it's definitely not a big deal for me.