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 <[email protected]> --- @Matt: here's v2 of 2/2 only, with your comments addressed. Thanks, Ard. drivers/firmware/efi/efi.c | 18 ++++++++++++++++++ include/linux/efi.h | 1 + 2 files changed, 19 insertions(+) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 5cbb8d31da33..8c81cd58f95f 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -425,6 +425,24 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz, } 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; } diff --git a/include/linux/efi.h b/include/linux/efi.h index 5b4f3ac08053..61b5a5e1e9be 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -972,6 +972,7 @@ extern int __init efi_setup_pcdp_console(char *); #define EFI_PARAVIRT 6 /* Access is via a paravirt interface */ #define EFI_ARCH_1 7 /* First arch-specific bit */ #define EFI_DBG 8 /* Print additional debug info at runtime */ +#define EFI_NX_PE_DATA 9 /* Can runtime data regions be mapped non-executable? */ #ifdef CONFIG_EFI /* -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
