efi: Introduce EFI_NX_PE_DATA bit and set it from properties table
UEFI v2.5 introduces a runtime memory protection feature that splits
PE/COFF runtime images into separate code and data regions. Since this
may require special handling by the OS, allocate a EFI_xxx bit to
keep track of whether this feature is currently active or not.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index c297d78..31fc864 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -426,6 +426,24 @@
}
pr_cont("\n");
set_bit(EFI_CONFIG_TABLES, &efi.flags);
+
+ /* Parse the EFI Properties table if it exists */
+ if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
+ efi_properties_table_t *tbl;
+
+ tbl = early_memremap(efi.properties_table, sizeof(*tbl));
+ if (tbl == NULL) {
+ pr_err("Could not map Properties table!\n");
+ return -ENOMEM;
+ }
+
+ if (tbl->memory_protection_attribute &
+ EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
+ set_bit(EFI_NX_PE_DATA, &efi.flags);
+
+ early_memunmap(tbl, sizeof(*tbl));
+ }
+
return 0;
}