linux-kernel - Re: [PATCH] compiler-gcc.h: Disable _

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Message-ID: <87bk03zphj.fsf@igel.home>
Date: Tue, 01 Oct 2024 19:45:28 +0200
From: Andreas Schwab <schwab@...ux-m68k.org>
To: Tony Ambardar <tony.ambardar@...il.com>
Cc: Geert Uytterhoeven <geert+renesas@...der.be>,  Daniel Borkmann
 <daniel@...earbox.net>,  Miguel Ojeda <ojeda@...nel.org>,  Jiri Olsa
 <jolsa@...nel.org>,  Andrew Morton <akpm@...ux-foundation.org>,  Arnd
 Bergmann <arnd@...db.de>,  linux-kernel@...r.kernel.org
Subject: Re: [PATCH] compiler-gcc.h: Disable __retain on gcc-11

On Sep 30 2024, Tony Ambardar wrote:

> On Tue, Sep 24, 2024 at 07:29:46PM +0200, Andreas Schwab wrote:
>> On Sep 24 2024, Geert Uytterhoeven wrote:
>> 
>> > All my gcc-11 compilers (Ubuntu 11.4.0-1ubuntu1~22.04) claim to support
>> > the __retain__ attribute, but only riscv64-linux-gnu-gcc-11 and
>> > x86_64-linux-gnu-gcc-11 (not x86_64-linux-gnux32-gcc-11!) actually do.
>> > The arm-linux-gnueabi-gcc-11.5.0 compiler from kernel.org crosstool
>> > fails in the same way:
>> >
>> >     error: ‘retain’ attribute ignored [-Werror=attributes]
>> >
>> > All my gcc-12 compilers seem to support the attribute.
>> 
>> That ultimately depends on binutils support for SHF_GNU_RETAIN (2.36+).
>
> IIRC from working on the original patch, older linkers which do not
> support this 'R' flag would simply ignore it and not error out,

The assembler gives a fatal error for unrecognized section attributes
since binutils 2.15, and emitted a warning before that (but the gcc
check uses --fatal-warnings).

-- 
Andreas Schwab, schwab@...ux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
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