On 14 September 2017 at 12:31, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: > The UEFI memory map *spec* > is a bit vague about how to interpret the > EFI_MEMORY_XP attribute when it is combined with EFI_MEMORY_RP and/or > EFI_MEMORY_WP, which have retroactively been redefined as cacheability > attributes rather than permission attributes. > > So let's ignore EFI_MEMORY_XP if _RP and/or _WP are also set. In this > case, it is likely that they are being used to describe the capability > of the region (i.e., whether it has the controls to reconfigure it as > non-executable) rather than the nature of the contents of the region > (i.e., whether it contains data that we will never attempt to execute) > > Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> > Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> > --- > arch/arm64/kernel/efi.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c > index 82cd07592519..f85ac58d08a3 100644 > --- a/arch/arm64/kernel/efi.c > +++ b/arch/arm64/kernel/efi.c > @@ -48,7 +48,9 @@ static __init pteval_t create_mapping_protection(efi_memory_desc_t *md) > return pgprot_val(PAGE_KERNEL_ROX); > > /* RW- */ > - if (attr & EFI_MEMORY_XP || type != EFI_RUNTIME_SERVICES_CODE) > + if (((attr & (EFI_MEMORY_RP | EFI_MEMORY_WP | EFI_MEMORY_XP)) == > + EFI_MEMORY_XP) || > + type != EFI_RUNTIME_SERVICES_CODE) > return pgprot_val(PAGE_KERNEL); > > /* RWX */ > -- > 2.11.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
