On Fri, Dec 21, 2018 at 12:54:46PM +0100, Ard Biesheuvel wrote:
> This reverts commit 793423cf07e51e3185b8680167115813589c057d.
>
> The 64-bit alignment affects the size of efi_config_table_32_t,
> which is used as an array type. On the other hand, the former
> byte alignment could trigger alignment faults during firmware
> calls on 32-bit ARM, since UEFI defines efi_guid_t as a struct
> of UINT32 + UINT16 + UINT16 + UINT8[8], and so it may use load/
> store multiple instructions [requiring 32-bit alignment], e.g.,
> on GUID pointers passed as function arguments since UEFI's view
> of the type has implicit 32-bit alignment.
>
> Let's sort this out for the next release, and revert the change
> for now.
>
> Fixes: 793423cf07e5 ("efi: Align 'efi_guid_t' to 64 bits")
> Reported-by: Heinrich Schuchardt <xypron.glpk@xxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Andy Lutomirski <luto@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Cc: H. Peter Anvin <hpa@xxxxxxxxx>
> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Qian Cai <cai@xxxxxx>
> Cc: Rik van Riel <riel@xxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> ---
> include/linux/efi.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index e6480c805932..100ce4a4aff6 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -48,7 +48,7 @@ typedef u16 efi_char16_t; /* UNICODE character */
> typedef u64 efi_physical_addr_t;
> typedef void *efi_handle_t;
>
> -typedef guid_t efi_guid_t __aligned(8);
> +typedef guid_t efi_guid_t;
>
> #define EFI_GUID(a,b,c,d0,d1,d2,d3,d4,d5,d6,d7) \
> GUID_INIT(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)
> --
It was the top commit on tip:efi/urgent so I've zapped it.
HTH.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
