| From | Evgeniy Baskov <> | Subject | [PATCH v4 26/26] efi/x86: don't set unsupported memory attributes | Date | Thu, 15 Dec 2022 15:38:17 +0300 |
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From: Peter Jones <pjones@redhat.com>
On platforms where the firmware uses DXE, but which do not implement the EFI Memory Attribute Protocol, we implement W^X support using DXE's set_memory_attributes() call. This call will fail without making any changes if an attribute is set that isn't supported on the platform.
This patch changes efi_adjust_memory_range_protection() to avoid trying to set any attribute bits that aren't set in the memory region's capability flags.
Signed-off-by: Peter Jones <pjones@redhat.com> --- drivers/firmware/efi/libstub/mem.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/firmware/efi/libstub/mem.c b/drivers/firmware/efi/libstub/mem.c index 50a0b649b75a..b86ea2920d5e 100644 --- a/drivers/firmware/efi/libstub/mem.c +++ b/drivers/firmware/efi/libstub/mem.c @@ -195,6 +195,7 @@ static efi_status_t adjust_mem_attrib_dxe(efi_physical_addr_t rounded_start, desc.attributes &= ~(EFI_MEMORY_RO | EFI_MEMORY_XP); desc.attributes |= attributes; + desc.attributes &= desc.capabilities; unprotect_start = max(rounded_start, desc.base_address); unprotect_size = min(rounded_end, next) - unprotect_start; -- 2.37.4
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