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From: Andrey Ignatov <rdna@fb.com>
To: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Ard Biesheuvel <ardb@kernel.org>, <linux-efi@vger.kernel.org>,
	<bpf@vger.kernel.org>
Subject: Re: [PATCH] efi/x86: Fix build with gcc 4
Date: Fri, 5 Jun 2020 09:09:46 -0700	[thread overview]
Message-ID: <20200605160946.GA46739@rdna-mbp.dhcp.thefacebook.com> (raw)
In-Reply-To: <20200605150638.1011637-1-nivedita@alum.mit.edu>

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.

> ---
>  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

  reply	other threads:[~2020-06-05 16:09 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-18 19:06 [PATCH 00/24] efi/libstub: Add printf implementation Arvind Sankar
2020-05-18 19:06 ` [PATCH 01/24] efi/libstub: Include dependencies of efistub.h Arvind Sankar
2020-05-18 19:06 ` [PATCH 02/24] efi/libstub: Rename efi_[char16_]printk to efi_[char16_]puts Arvind Sankar
2020-05-18 19:06 ` [PATCH 03/24] efi/libstub: Buffer output of efi_puts Arvind Sankar
2020-05-18 19:06 ` [PATCH 04/24] efi/libstub: Add a basic printf implementation Arvind Sankar
2020-05-18 19:06 ` [PATCH 05/24] efi/libstub: Optimize for size instead of speed Arvind Sankar
2020-06-05  0:31   ` 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 [this message]
2020-06-15  9:43               ` Ard Biesheuvel
2020-05-18 19:06 ` [PATCH 06/24] efi/printf: Drop %n format and L qualifier Arvind Sankar
2020-05-18 19:06 ` [PATCH 07/24] efi/printf: Add 64-bit and 8-bit integer support Arvind Sankar
2020-05-18 19:07 ` [PATCH 08/24] efi/printf: Factor out flags parsing and handle '%' earlier Arvind Sankar
2020-05-18 19:07 ` [PATCH 09/24] efi/printf: Fix minor bug in precision handling Arvind Sankar
2020-05-18 19:07 ` [PATCH 10/24] efi/printf: Merge 'p' with the integer formats Arvind Sankar
2020-05-18 19:07 ` [PATCH 11/24] efi/printf: Factor out width/precision parsing Arvind Sankar
2020-05-18 19:07 ` [PATCH 12/24] efi/printf: Factor out integer argument retrieval Arvind Sankar
2020-05-18 19:07 ` [PATCH 13/24] efi/printf: Handle null string input Arvind Sankar
2020-05-18 19:07 ` [PATCH 14/24] efi/printf: Refactor code to consolidate padding and output Arvind Sankar
2020-05-18 19:07 ` [PATCH 15/24] efi/printf: Abort on invalid format Arvind Sankar
2020-05-18 19:07 ` [PATCH 16/24] efi/printf: Turn vsprintf into vsnprintf Arvind Sankar
2020-05-18 19:07 ` [PATCH 17/24] efi/libstub: Implement printk-style logging Arvind Sankar
2020-05-19  8:22   ` Ard Biesheuvel
2020-05-19 15:07     ` Arvind Sankar
2020-05-20 16:38       ` Arvind Sankar
2020-05-20 16:38         ` Ard Biesheuvel
2020-05-20 17:02           ` Arvind Sankar
2020-05-20 17:09             ` Ard Biesheuvel
2020-05-18 19:07 ` [PATCH 18/24] efi/libstub: Add definitions for console input and events Arvind Sankar
2020-05-18 19:07 ` [PATCH 19/24] efi/gop: Add an option to list out the available GOP modes Arvind Sankar
2020-05-18 19:07 ` [PATCH 20/24] efi/printf: Add support for wchar_t (UTF-16) Arvind Sankar
2020-05-18 19:07 ` [PATCH 21/24] efi/libstub: Add UTF-8 decoding to efi_puts Arvind Sankar
2020-05-18 19:07 ` [PATCH 22/24] efi/libstub: Use %ls for filename Arvind Sankar
2020-05-18 19:07 ` [PATCH 23/24] efi/libstub: Get the exact UTF-8 length Arvind Sankar
2020-05-18 19:07 ` [PATCH 24/24] efi/libstub: Use snprintf with %ls to convert the command line Arvind Sankar
2020-05-19  7:53 ` [PATCH 00/24] efi/libstub: Add printf implementation Ard Biesheuvel
2020-05-19 15:06   ` Arvind Sankar
2020-05-19 16:44     ` Ard Biesheuvel
2020-05-21  0:29       ` [PATCH] efi/libstub: Don't parse overlong command lines Arvind Sankar
2020-05-22 13:13         ` Ard Biesheuvel

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