diff options
| author | Ard Biesheuvel | 2023-04-18 15:49:49 +0200 |
|---|---|---|
| committer | Ard Biesheuvel | 2023-04-26 18:01:41 +0200 |
| commit | 45dd403da851124412d32e3193c21de4a51d29da (patch) | |
| tree | db4606bec41de6a73ca1a9929840f73520207266 | |
| parent | 538bc0f40b364f2c7b81f11aa163f723b138b40f (diff) | |
efi/zboot: arm64: Inject kernel code size symbol into the zboot payload
The EFI zboot code is not built as part of the kernel proper, like the
ordinary EFI stub, but still needs access to symbols that are defined
only internally in the kernel, and are left unexposed deliberately to
avoid creating ABI inadvertently that we're stuck with later.
So capture the kernel code size of the kernel image, and inject it as an
ELF symbol into the object that contains the compressed payload, where
it will be accessible to zboot code that needs it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
| -rw-r--r-- | arch/arm64/boot/Makefile | 3 | ||||
| -rw-r--r-- | arch/arm64/kernel/image-vars.h | 4 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/Makefile.zboot | 2 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/zboot.lds | 7 |
4 files changed, 15 insertions, 1 deletions
diff --git a/arch/arm64/boot/Makefile b/arch/arm64/boot/Makefile index ae645fda90bc..1761f5972443 100644 --- a/arch/arm64/boot/Makefile +++ b/arch/arm64/boot/Makefile @@ -44,4 +44,7 @@ EFI_ZBOOT_BFD_TARGET := elf64-littleaarch64 EFI_ZBOOT_MACH_TYPE := ARM64 EFI_ZBOOT_FORWARD_CFI := $(CONFIG_ARM64_BTI_KERNEL) +EFI_ZBOOT_OBJCOPY_FLAGS = --add-symbol zboot_code_size=0x$(shell \ + $(NM) vmlinux|grep _kernel_codesize|cut -d' ' -f1) + include $(srctree)/drivers/firmware/efi/libstub/Makefile.zboot diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h index 8309197c0ebd..35f3c7959513 100644 --- a/arch/arm64/kernel/image-vars.h +++ b/arch/arm64/kernel/image-vars.h @@ -108,4 +108,8 @@ KVM_NVHE_ALIAS(kvm_protected_mode_initialized); #endif /* CONFIG_KVM */ +#ifdef CONFIG_EFI_ZBOOT +_kernel_codesize = ABSOLUTE(__inittext_end - _text); +#endif + #endif /* __ARM64_KERNEL_IMAGE_VARS_H */ diff --git a/drivers/firmware/efi/libstub/Makefile.zboot b/drivers/firmware/efi/libstub/Makefile.zboot index 0a9dcc2b1373..1b101d9076fd 100644 --- a/drivers/firmware/efi/libstub/Makefile.zboot +++ b/drivers/firmware/efi/libstub/Makefile.zboot @@ -40,7 +40,7 @@ quiet_cmd_compwithsize = $(quiet_cmd_$(zboot-method-y)) $(obj)/vmlinuz: $(obj)/vmlinux.bin FORCE $(call if_changed,compwithsize) -OBJCOPYFLAGS_vmlinuz.o := -I binary -O $(EFI_ZBOOT_BFD_TARGET) \ +OBJCOPYFLAGS_vmlinuz.o := -I binary -O $(EFI_ZBOOT_BFD_TARGET) $(EFI_ZBOOT_OBJCOPY_FLAGS) \ --rename-section .data=.gzdata,load,alloc,readonly,contents $(obj)/vmlinuz.o: $(obj)/vmlinuz FORCE $(call if_changed,objcopy) diff --git a/drivers/firmware/efi/libstub/zboot.lds b/drivers/firmware/efi/libstub/zboot.lds index 93d33f68333b..ac8c0ef85158 100644 --- a/drivers/firmware/efi/libstub/zboot.lds +++ b/drivers/firmware/efi/libstub/zboot.lds @@ -2,6 +2,8 @@ ENTRY(__efistub_efi_zboot_header); +PROVIDE(zboot_code_size = ABSOLUTE(0)); + SECTIONS { .head : ALIGN(4096) { @@ -17,6 +19,11 @@ SECTIONS *(.gzdata) __efistub__gzdata_end = .; *(.rodata* .init.rodata* .srodata*) + + . = ALIGN(4); + __efistub_code_size = .; + LONG(zboot_code_size); + _etext = ALIGN(4096); . = _etext; } |