Re: [PATCH 05/24] efi/libstub: Optimize for size instead of speed

[Ard Biesheuvel <ardb@kernel.org>]

Hello Andrey,

On Fri, 5 Jun 2020 at 02:31, Andrey Ignatov <rdna@fb.com> wrote:
>
> Arvind Sankar <nivedita@alum.mit.edu> [Wed, 1969-12-31 23:00 -0800]:
> > Reclaim the bloat from the addition of printf by optimizing the stub for
> > size. With gcc 9, the text size of the stub is:
> >
> > ARCH    before  +printf    -Os
> > arm      35197    37889  34638
> > arm64    34883    38159  34479
> > i386     18571    21657  17025
> > x86_64   25677    29328  22144
> >
> > Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
> > ---
> >  drivers/firmware/efi/libstub/Makefile | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
> > index fb34c9d14a3c..034d71663b1e 100644
> > --- a/drivers/firmware/efi/libstub/Makefile
> > +++ b/drivers/firmware/efi/libstub/Makefile
> > @@ -7,7 +7,7 @@
> >  #
> >  cflags-$(CONFIG_X86_32)              := -march=i386
> >  cflags-$(CONFIG_X86_64)              := -mcmodel=small
> > -cflags-$(CONFIG_X86)         += -m$(BITS) -D__KERNEL__ -O2 \
> > +cflags-$(CONFIG_X86)         += -m$(BITS) -D__KERNEL__ \
> >                                  -fPIC -fno-strict-aliasing -mno-red-zone \
> >                                  -mno-mmx -mno-sse -fshort-wchar \
> >                                  -Wno-pointer-sign \
> > @@ -25,7 +25,7 @@ cflags-$(CONFIG_ARM)                := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
> >
> >  cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt
> >
> > -KBUILD_CFLAGS                        := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
> > +KBUILD_CFLAGS                        := $(cflags-y) -Os -DDISABLE_BRANCH_PROFILING \
> >                                  -include $(srctree)/drivers/firmware/efi/libstub/hidden.h \
> >                                  -D__NO_FORTIFY \
> >                                  $(call cc-option,-ffreestanding) \
>
> Hi Arvind,
>
> This patch breaks build for me:
>
> $>make -j32 -s bzImage
> drivers/firmware/efi/libstub/alignedmem.c: In function \x2018efi_allocate_pages_aligned\x2019:
> drivers/firmware/efi/libstub/alignedmem.c:38:9: sorry, unimplemented: ms_abi attribute requires -maccumulate-outgoing-args or subtarget optimization implying it
>   status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS,
>          ^

Which version of GCC are you using?


> In file included from drivers/firmware/efi/libstub/alignedmem.c:6:0:
> drivers/firmware/efi/libstub/efistub.h:49:64: sorry, unimplemented: ms_abi attribute requires -maccumulate-outgoing-args or subtarget optimization implying it
>  #define efi_bs_call(func, ...) efi_system_table->boottime->func(__VA_ARGS__)
>                                                                 ^
> drivers/firmware/efi/libstub/alignedmem.c:50:4: note: in expansion of macro \x2018efi_bs_call\x2019
>     efi_bs_call(free_pages, alloc_addr, slack - l + 1);
>     ^
> drivers/firmware/efi/libstub/alignedmem.c:50: confused by earlier errors, bailing out
> In file included from drivers/firmware/efi/libstub/efi-stub-helper.c:19:0:
> drivers/firmware/efi/libstub/efi-stub-helper.c: In function \x2018efi_char16_puts\x2019:
> drivers/firmware/efi/libstub/efistub.h:52:51: sorry, unimplemented: ms_abi attribute requires -maccumulate-outgoing-args or subtarget optimization implying it
>  #define efi_call_proto(inst, func, ...) inst->func(inst, ##__VA_ARGS__)
>                                                    ^
> drivers/firmware/efi/libstub/efi-stub-helper.c:37:2: note: in expansion of macro \x2018efi_call_proto\x2019
>   efi_call_proto(efi_table_attr(efi_system_table, con_out),
>   ^
> drivers/firmware/efi/libstub/efi-stub-helper.c:37: confused by earlier errors, bailing out
> drivers/firmware/efi/libstub/file.c: In function \x2018handle_cmdline_files\x2019:
> drivers/firmware/efi/libstub/file.c:73:9: sorry, unimplemented: ms_abi attribute requires -maccumulate-outgoing-args or subtarget optimization implying it
>   status = efi_bs_call(handle_protocol, image->device_handle, &fs_proto,
>          ^
> drivers/firmware/efi/libstub/file.c:73: confused by earlier errors, bailing out
> Preprocessed source stored into /tmp/ccc4T4FI.out file, please attach this to your bugreport.
> make[5]: *** [drivers/firmware/efi/libstub/alignedmem.o] Error 1
> make[5]: *** Waiting for unfinished jobs....
> drivers/firmware/efi/libstub/gop.c: In function \x2018efi_setup_gop\x2019:
> drivers/firmware/efi/libstub/gop.c:565:9: sorry, unimplemented: ms_abi attribute requires -maccumulate-outgoing-args or subtarget optimization implying it
>   status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
>          ^
> drivers/firmware/efi/libstub/gop.c:565: confused by earlier errors, bailing out
> Preprocessed source stored into /tmp/ccgQG7p4.out file, please attach this to your bugreport.
> make[5]: *** [drivers/firmware/efi/libstub/efi-stub-helper.o] Error 1
> Preprocessed source stored into /tmp/ccnqGnqG.out file, please attach this to your bugreport.
> make[5]: *** [drivers/firmware/efi/libstub/file.o] Error 1
> Preprocessed source stored into /tmp/ccle7n2N.out file, please attach this to your bugreport.
> make[5]: *** [drivers/firmware/efi/libstub/gop.o] Error 1
> make[4]: *** [drivers/firmware/efi/libstub] Error 2
> make[3]: *** [drivers/firmware/efi] Error 2
> make[2]: *** [drivers/firmware] Error 2
> make[2]: *** Waiting for unfinished jobs....
> make[1]: *** [drivers] Error 2
> make[1]: *** Waiting for unfinished jobs....
> make: *** [sub-make] Error 2
>
> Either reverting the patch or disabling CONFIG_EFI_STUB fixes it.
>
> Initially I found it on bpf/bpf-next HEAD but same happens on
> torvalds/linux.
>
> I attach the config I used.
>
> --
> Andrey Ignatov