linux-kernel - Re: [PATCH] [RFC, DO NOT APPLY] vmlinux.lds: revert link speed regression

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: <CAF1bQ=SEybO_+UMDqspA+9OecYqJhE56D-zJyxEUiPcj+Af_fA@mail.gmail.com>
Date: Wed, 22 Jan 2025 10:47:54 -0800
From: Rong Xu <xur@...gle.com>
To: Arnd Bergmann <arnd@...db.de>
Cc: Arnd Bergmann <arnd@...nel.org>, linux-kbuild@...r.kernel.org, 
	Masahiro Yamada <masahiroy@...nel.org>, linux-kernel@...r.kernel.org, 
	regressions@...ts.linux.dev, Han Shen <shenhan@...gle.com>, 
	Nathan Chancellor <nathan@...nel.org>, Kees Cook <kees@...nel.org>, Jann Horn <jannh@...gle.com>, 
	Ard Biesheuvel <ardb@...nel.org>, Linux-Arch <linux-arch@...r.kernel.org>
Subject: Re: [PATCH] [RFC, DO NOT APPLY] vmlinux.lds: revert link speed regression

On Tue, Jan 21, 2025 at 1:18 PM Arnd Bergmann <arnd@...db.de> wrote:
>
> On Tue, Jan 21, 2025, at 18:45, Rong Xu wrote:
> > On Mon, Jan 20, 2025 at 1:29 PM Arnd Bergmann <arnd@...nel.org> wrote:
> >
> > Yes. The order could be conditional. As a matter of fact, the first
> > version was conditional.
> > I changed it based on the reviewer comments to reduce conditions for
> > more maintainable code.
> > I would like to work from the ld.bfd side to see if we can fix the problem.
>
> Makes sense. At least once we understand what makes the linker so slow
> and fix future versions, it should also be possible to come up with
> a more effective workaround for the existing linkers that suffer from it.

@Arnd: Can you send me the instructions to reproduce this regression?

I tried my x86-64 machine in v6.13 kernel with the following ld.bfd:
(1) GNU ld (GNU Binutils) 2.36.90.20210703
(2) GNU ld (GNU Binutils) 2.39.90.20221231
(3) GNU ld (GNU Binutils for Debian) 2.42.50.20240625
They all used about ~2s to link vmlinux.o.

The config I used was "make randconfig".

Thanks,

-Rong

>
>      Arnd