[PATCH 5/5] efi: use string literals for efi_char16_t variable initializers

From: Ard Biesheuvel
Date: Mon Mar 12 2018 - 04:45:50 EST


Now that we unambiguously build the entire kernel with -fshort-wchar,
it is no longer necessary to open code efi_char16_t[] initializers as
arrays of characters, and we can move to the L"xxx" notation instead.

Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Lukas Wunner <lukas@xxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/x86/boot/compressed/eboot.c | 3 ++-
arch/x86/platform/efi/quirks.c | 8 +++++---
drivers/firmware/efi/libstub/Makefile | 2 +-
drivers/firmware/efi/libstub/secureboot.c | 12 +++---------
drivers/firmware/efi/libstub/tpm.c | 7 ++-----
5 files changed, 13 insertions(+), 19 deletions(-)

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index f2251c1c9853..47d3efff6805 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -421,9 +421,10 @@ static void retrieve_apple_device_properties(struct boot_params *boot_params)
}
}

+static const efi_char16_t apple[] = L"Apple";
+
static void setup_quirks(struct boot_params *boot_params)
{
- static efi_char16_t const apple[] = { 'A', 'p', 'p', 'l', 'e', 0 };
efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
efi_table_attr(efi_system_table, fw_vendor, sys_table);

diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 1ef11c26f79b..36c1f8b9f7e0 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -75,7 +75,7 @@ struct quark_security_header {
u32 rsvd[2];
};

-static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
+static const efi_char16_t efi_dummy_name[] = L"DUMMY";

static bool efi_no_storage_paranoia;

@@ -105,7 +105,8 @@ early_param("efi_no_storage_paranoia", setup_storage_paranoia);
*/
void efi_delete_dummy_variable(void)
{
- efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ efi.set_variable((efi_char16_t *)efi_dummy_name,
+ &EFI_DUMMY_GUID,
EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
@@ -182,7 +183,8 @@ efi_status_t efi_query_variable_store(u32 attributes, unsigned long size,
if (!dummy)
return EFI_OUT_OF_RESOURCES;

- status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ status = efi.set_variable((efi_char16_t *)efi_dummy_name,
+ &EFI_DUMMY_GUID,
EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 7b3ba40f0745..a34e9290a699 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -9,7 +9,7 @@ cflags-$(CONFIG_X86_32) := -march=i386
cflags-$(CONFIG_X86_64) := -mcmodel=small
cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ -O2 \
-fPIC -fno-strict-aliasing -mno-red-zone \
- -mno-mmx -mno-sse
+ -mno-mmx -mno-sse -fshort-wchar

cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie
cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \
diff --git a/drivers/firmware/efi/libstub/secureboot.c b/drivers/firmware/efi/libstub/secureboot.c
index 959777ec8a77..8f07eb414c00 100644
--- a/drivers/firmware/efi/libstub/secureboot.c
+++ b/drivers/firmware/efi/libstub/secureboot.c
@@ -16,18 +16,12 @@

/* BIOS variables */
static const efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
-static const efi_char16_t efi_SecureBoot_name[] = {
- 'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0
-};
-static const efi_char16_t efi_SetupMode_name[] = {
- 'S', 'e', 't', 'u', 'p', 'M', 'o', 'd', 'e', 0
-};
+static const efi_char16_t efi_SecureBoot_name[] = L"SecureBoot";
+static const efi_char16_t efi_SetupMode_name[] = L"SetupMode";

/* SHIM variables */
static const efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID;
-static efi_char16_t const shim_MokSBState_name[] = {
- 'M', 'o', 'k', 'S', 'B', 'S', 't', 'a', 't', 'e', 0
-};
+static const efi_char16_t shim_MokSBState_name[] = L"MokSBState";

#define get_efi_var(name, vendor, ...) \
efi_call_runtime(get_variable, \
diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c
index da661bf8cb96..2298560cea72 100644
--- a/drivers/firmware/efi/libstub/tpm.c
+++ b/drivers/firmware/efi/libstub/tpm.c
@@ -16,11 +16,8 @@
#include "efistub.h"

#ifdef CONFIG_RESET_ATTACK_MITIGATION
-static const efi_char16_t efi_MemoryOverWriteRequest_name[] = {
- 'M', 'e', 'm', 'o', 'r', 'y', 'O', 'v', 'e', 'r', 'w', 'r', 'i', 't',
- 'e', 'R', 'e', 'q', 'u', 'e', 's', 't', 'C', 'o', 'n', 't', 'r', 'o',
- 'l', 0
-};
+static const efi_char16_t efi_MemoryOverWriteRequest_name[] =
+ L"MemoryOverwriteRequestControl";

#define MEMORY_ONLY_RESET_CONTROL_GUID \
EFI_GUID(0xe20939be, 0x32d4, 0x41be, 0xa1, 0x50, 0x89, 0x7f, 0x85, 0xd4, 0x98, 0x29)
--
2.15.1