Re: [RESEND PATCH v2 0/2] efi/libstub: Ensure instruction cache coherency after kernel relocation

[Ard Biesheuvel]

On Mon, 27 Apr 2026, at 18:11, Ard Biesheuvel wrote:
> On Mon, 27 Apr 2026, at 10:47, WANG Rui wrote:
>> Changes since [v1]:
>>   * Move efi_cache_sync_image() after check_platform_features(), matching arm64.
>>   * Add "()" after function name in the subject.
>>
>> The EFI stub relocates the kernel image by copying it to a new memory
>> location using memcpy(). On architectures where the instruction and data
>> caches are not automatically coherent, the copied instructions may not be
>> visible to the instruction fetch unit without explicit cache maintenance.
>>
>> This series adds the missing call to efi_cache_sync_image() in the generic
>> relocation path, and provides a LoongArch implementation using the ibar
>> instruction to ensure instruction fetches observe the updated contents.
>>
>> [v1]: https://lore.kernel.org/loongarch/20260427034451.717817-1-r@xxxxxx
>>
>> WANG Rui (2):
>>   efi/loongarch: Implement efi_cache_sync_image
>>   efi/libstub: Synchronize instruction cache after kernel relocation
>>
>
> Queued up in efi/urgent - thanks.
>

This breaks the ARM build.

Since LoongArch is the only remaining user of efi_relocate_kernel(), I'll move it into drivers/firmware/efi/libstub/loongarch-stub.c first, and fix up these patches accordingly afterwards (no need to resend anything)