Re: [PATCH-next v3] arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION

From: liuyuntao (F)
Date: Fri Mar 15 2024 - 08:22:11 EST




On 2024/3/15 20:13, Ard Biesheuvel wrote:
On Fri, 15 Mar 2024 at 13:10, liuyuntao (F) <liuyuntao12@xxxxxxxxxx> wrote:



On 2024/3/15 19:51, Arnd Bergmann wrote:
On Fri, Mar 15, 2024, at 12:48, liuyuntao (F) wrote:
On 2024/3/15 18:46, Ard Biesheuvel wrote:
@@ -28,6 +28,7 @@
-DEFI_HAVE_MEMCHR -DEFI_HAVE_STRRCHR \
-DEFI_HAVE_STRCMP -fno-builtin -fpic \
$(call cc-option,-mno-single-pic-base)
+cflags-$(CONFIG_ARM) := $(filter-out -fdata-sections, $(CFLAGS-y))
cflags-$(CONFIG_RISCV) += -fpic -DNO_ALTERNATIVE -mno-relax
cflags-$(CONFIG_LOONGARCH) += -fpie

Another error:
cannot initialize array of ‘short unsigned int’ from a string literal
with type array of ‘unsigned int’
17 | static const efi_char16_t shim_MokSBState_name[] = L"MokSBStateRT";

The line sets cflags-y to an empty string.

It probably should have been

cflags-$(CONFIG_ARM) := $(filter-out -fdata-sections, $(cflags-y))

(small cflags instead of CFLAGS).


Oops indeed.

Oh, my mistake, after fixed this bug, still this error:
arm-linux-gnueabi-ld: warning: orphan section `.data.efi_loglevel' from `drivers/firmware/efi/libstub/printk.stub.o' being placed in section `.data.efi_loglevel'
arm-linux-gnueabi-ld: warning: orphan section `.data.screen_info_guid' from `drivers/firmware/efi/libstub/screen_info.stub.o' being placed in section `.data.screen_info_guid'
arm-linux-gnueabi-ld: warning: orphan section `.data.cpu_state_guid' from `drivers/firmware/efi/libstub/arm32-stub.stub.o' being placed in section `.data.cpu_state_guid'
arm-linux-gnueabi-ld: warning: orphan section `.data.efi_nokaslr' from `drivers/firmware/efi/libstub/efi-stub-helper.stub.o' being placed in section `.data.efi_nokaslr'

The -fdata-sections option is present in the KBUILD_CFLAGS_KERNEL
variable; altering cflags-y only affect the KBUILD_CFLAGS variable.
It seems that the -fdata-sections option needs to be removed from the
KBUILD_CFLAGS_KERNEL variable.

Indeed.

So

KBUILD_CFLAGS_KERNEL := $(filter-out -fdata-sections,$(KBUILD_CFLAGS_KERNEL))

(assuming I got it right this time without build testing)

Um, it not worked,too, same error.
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -28,6 +28,7 @@ cflags-$(CONFIG_ARM) += -DEFI_HAVE_STRLEN -DEFI_HAVE_STRNLEN \
-DEFI_HAVE_MEMCHR -DEFI_HAVE_STRRCHR \
-DEFI_HAVE_STRCMP -fno-builtin -fpic \
$(call cc-option,-mno-single-pic-base)
+KBUILD_CFLAGS_KERNE := $(filter-out -fdata-sections, $(KBUILD_CFLAGS_KERNE))
cflags-$(CONFIG_RISCV) += -fpic -DNO_ALTERNATIVE -mno-relax
cflags-$(CONFIG_LOONGARCH) += -fpie