Re: [PATCH] x86/alternative: delay freeing of smp_locks section

[Borislav Petkov]

On Sat, Mar 28, 2026 at 11:16:34AM +0300, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>
> 
> On UP systems alternative_instructions() frees memory occupied by smp_locks

UP systems?

I don't understand - Bert's machine is a SMP.

> section immediately after patching the lock instructions.
> 
> With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled this happens before the
> memory map is fully initialized and the struct pages representing the freed
> memory might get overwritten by deferred initialization of the memory map.
> 
> Move freeing of smp_locks section to an initcall to ensure it will happen
> after the memory map is fully initialized.
> 
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
> Tested-By: Bert Karwatzki <spasswolf@xxxxxx>

I don't understand even more: why have we not hit this before?

No Fixes: tag?

Something must've changed for this to fire...

-- 
Regards/Gruss,
    Boris.

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