From a1041713349d0b823b492d7b4ea4325d0b5666db Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 23 Sep 2015 07:29:34 -0700 Subject: [PATCH] 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 Cc: Leif Lindholm Signed-off-by: Matt Fleming --- 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 c297d78f50fd..31fc864eb037 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -426,6 +426,24 @@ 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 d6a9bee755f2..fa5106c2f9f5 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -973,6 +973,7 @@ 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 /* -- 2.39.2