Commit-ID: 1e9de1d2207d67b97bb0b62e38454b663d6542fa Gitweb: https://git.kernel.org/tip/1e9de1d2207d67b97bb0b62e38454b663d6542fa Author: Ard Biesheuvel <[email protected]> AuthorDate: Tue, 2 Jan 2018 18:10:39 +0000 Committer: Ingo Molnar <[email protected]> CommitDate: Wed, 3 Jan 2018 14:03:48 +0100
arm64/efi: Ignore EFI_MEMORY_XP attribute if RP and/or WP are set The UEFI memory map 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) Reported-by: Stephen Boyd <[email protected]> Tested-by: Stephen Boyd <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Yadav <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tyler Baicar <[email protected]> Cc: Vasyl Gomonovych <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- 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 82cd075..f85ac58 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 */
