From: Ard Biesheuvel <ardb@kernel.org>
To: Andrey Ignatov <rdna@fb.com>
Cc: Arvind Sankar <nivedita@alum.mit.edu>,
linux-efi <linux-efi@vger.kernel.org>,
bpf@vger.kernel.org
Subject: Re: [PATCH] efi/x86: Fix build with gcc 4
Date: Mon, 15 Jun 2020 11:43:32 +0200 [thread overview]
Message-ID: <CAMj1kXH+5MX5-Bn6tLBvFTKW4oh6L5D4DTxvEqcmrxQK8Yi8HA@mail.gmail.com> (raw)
In-Reply-To: <20200605160946.GA46739@rdna-mbp.dhcp.thefacebook.com>
On Fri, 5 Jun 2020 at 18:09, Andrey Ignatov <rdna@fb.com> wrote:
>
> Arvind Sankar <nivedita@alum.mit.edu> [Fri, 2020-06-05 08:06 -0700]:
> > Commit
> > bbf8e8b0fe04 ("efi/libstub: Optimize for size instead of speed")
> >
> > changed the optimization level for the EFI stub to -Os from -O2.
> >
> > Andrey Ignatov reports that this breaks the build with gcc 4.8.5.
> >
> > Testing on godbolt.org, the combination of -Os,
> > -fno-asynchronous-unwind-tables, and ms_abi functions doesn't work,
> > failing with the error:
> > sorry, unimplemented: ms_abi attribute requires
> > -maccumulate-outgoing-args or subtarget optimization implying it
> >
> > This does appear to work with gcc 4.9 onwards.
> >
> > Add -maccumulate-outgoing-args explicitly to unbreak the build with
> > pre-4.9 versions of gcc.
> >
> > Reported-by: Andrey Ignatov <rdna@fb.com>
> > Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
>
> Thanks. I confirmed it fixes the problem on my setup with gcc 4.8.5 and
> also works as before with clang 9.0.20190721.
>
Queued in efi/urgent, thanks.
> > ---
> > drivers/firmware/efi/libstub/Makefile | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
> > index cce4a7436052..d67418de768c 100644
> > --- a/drivers/firmware/efi/libstub/Makefile
> > +++ b/drivers/firmware/efi/libstub/Makefile
> > @@ -6,7 +6,8 @@
> > # enabled, even if doing so doesn't break the build.
> > #
> > cflags-$(CONFIG_X86_32) := -march=i386
> > -cflags-$(CONFIG_X86_64) := -mcmodel=small
> > +cflags-$(CONFIG_X86_64) := -mcmodel=small \
> > + $(call cc-option,-maccumulate-outgoing-args)
> > cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ \
> > -fPIC -fno-strict-aliasing -mno-red-zone \
> > -mno-mmx -mno-sse -fshort-wchar \
> > --
> > 2.26.2
> >
>
> --
> Andrey Ignatov
prev parent reply other threads:[~2020-06-15 9:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200518190716.751506-1-nivedita@alum.mit.edu>
[not found] ` <20200518190716.751506-6-nivedita@alum.mit.edu>
2020-06-05 0:31 ` [PATCH 05/24] efi/libstub: Optimize for size instead of speed Andrey Ignatov
2020-06-05 6:33 ` Ard Biesheuvel
2020-06-05 13:14 ` Arvind Sankar
2020-06-05 13:32 ` Arvind Sankar
2020-06-05 14:53 ` Ard Biesheuvel
2020-06-05 15:10 ` Arvind Sankar
2020-06-05 15:11 ` Ard Biesheuvel
2020-06-05 15:06 ` [PATCH] efi/x86: Fix build with gcc 4 Arvind Sankar
2020-06-05 16:09 ` Andrey Ignatov
2020-06-15 9:43 ` Ard Biesheuvel [this message]
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