arm64/efi: efistub: Apply __init annotation

This ensures all stub component are freed when the kernel proper is
done booting, by prefixing the names of all ELF sections that have
the SHF_ALLOC attribute with ".init". This approach ensures that even
implicitly emitted allocated data (like initializer values and string
literals) are covered.

At the same time, remove some __init annotations in the stub that have
now become redundant, and add the __init annotation to handle_kernel_image
which will now trigger a section mismatch warning without it.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
This commit is contained in:
Ard Biesheuvel 2015-01-12 20:28:20 +00:00 committed by Matt Fleming
parent 2859dff97e
commit ddeeefe2df
4 changed files with 26 additions and 12 deletions

View File

@ -13,13 +13,13 @@
#include <asm/efi.h>
#include <asm/sections.h>
efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
unsigned long *reserve_size,
unsigned long dram_base,
efi_loaded_image_t *image)
efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table,
unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
unsigned long *reserve_size,
unsigned long dram_base,
efi_loaded_image_t *image)
{
efi_status_t status;
unsigned long kernel_size, kernel_memsize = 0;

View File

@ -24,3 +24,17 @@ lib-y := efi-stub-helper.o
lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o
CFLAGS_fdt.o += -I$(srctree)/scripts/dtc/libfdt/
#
# arm64 puts the stub in the kernel proper, which will unnecessarily retain all
# code indefinitely unless it is annotated as __init/__initdata/__initconst etc.
# So let's apply the __init annotations at the section level, by prefixing
# the section names directly. This will ensure that even all the inline string
# literals are covered.
#
extra-$(CONFIG_ARM64) := $(lib-y)
lib-$(CONFIG_ARM64) := $(patsubst %.o,%.init.o,$(lib-y))
OBJCOPYFLAGS := --prefix-alloc-sections=.init
$(obj)/%.init.o: $(obj)/%.o FORCE
$(call if_changed,objcopy)

View File

@ -17,10 +17,10 @@
#include "efistub.h"
static int __init efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
{
static efi_guid_t const var_guid __initconst = EFI_GLOBAL_VARIABLE_GUID;
static efi_char16_t const var_name[] __initconst = {
static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID;
static efi_char16_t const var_name[] = {
'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 };
efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable;
@ -164,7 +164,7 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
* for both archictectures, with the arch-specific code provided in the
* handle_kernel_image() function.
*/
unsigned long __init efi_entry(void *handle, efi_system_table_t *sys_table,
unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
unsigned long *image_addr)
{
efi_loaded_image_t *image;

View File

@ -101,7 +101,7 @@ fail:
}
unsigned long __init get_dram_base(efi_system_table_t *sys_table_arg)
unsigned long get_dram_base(efi_system_table_t *sys_table_arg)
{
efi_status_t status;
unsigned long map_size;