linux-kernel - Re: [PATCH-next v3] arm32: enable HAVE_LD_DEAD_CODE_DATA

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <31f3a3fe-b16f-47a9-8c41-80fc0a236d52@huawei.com>
Date: Fri, 15 Mar 2024 20:21:55 +0800
From: "liuyuntao (F)" <liuyuntao12@...wei.com>
To: Ard Biesheuvel <ardb@...nel.org>
CC: Arnd Bergmann <arnd@...db.de>, <linux-arm-kernel@...ts.infradead.org>,
	<linux-kernel@...r.kernel.org>, Geert Uytterhoeven <geert@...ux-m68k.org>,
	Russell King <linux@...linux.org.uk>, Andrew Davis <afd@...com>, Andrew
 Morton <akpm@...ux-foundation.org>, "Kirill A. Shutemov"
	<kirill.shutemov@...ux.intel.com>, Geert Uytterhoeven
	<geert+renesas@...der.be>, Jonathan Corbet <corbet@....net>, Mike Rapoport
	<rppt@...nel.org>, Rob Herring <robh@...nel.org>, Thomas Gleixner
	<tglx@...utronix.de>, Linus Walleij <linus.walleij@...aro.org>, Fangrui Song
	<maskray@...gle.com>
Subject: Re: [PATCH-next v3] arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION



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