On Fri, 21 Dec 2018 at 13:13, Borislav Petkov <bp@xxxxxxxxx> wrote:
>
> 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.
>
Even better!
Thanks a lot
