linux-kernel - Re: [PATCH v2 1/3] vmlinux.lds.h: Add .gnu.version* to DISCARDS

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: <20200622220043.6j3vl6v7udmk2ppp@google.com>
Date:   Mon, 22 Jun 2020 15:00:43 -0700
From:   Fangrui Song <maskray@...gle.com>
To:     Kees Cook <keescook@...omium.org>
Cc:     Borislav Petkov <bp@...e.de>, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, x86@...nel.org,
        Arnd Bergmann <arnd@...db.de>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Nathan Chancellor <natechancellor@...il.com>,
        clang-built-linux@...glegroups.com, linux-arch@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/3] vmlinux.lds.h: Add .gnu.version* to DISCARDS

On 2020-06-22, Kees Cook wrote:
>For vmlinux linking, no architecture uses the .gnu.version* section,
>so remove it via the common DISCARDS macro in preparation for adding
>--orphan-handling=warn more widely.
>
>Signed-off-by: Kees Cook <keescook@...omium.org>
>---
> include/asm-generic/vmlinux.lds.h | 1 +
> 1 file changed, 1 insertion(+)
>
>diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
>index db600ef218d7..6fbe9ed10cdb 100644
>--- a/include/asm-generic/vmlinux.lds.h
>+++ b/include/asm-generic/vmlinux.lds.h
>@@ -934,6 +934,7 @@
> 	*(.discard)							\
> 	*(.discard.*)							\
> 	*(.modinfo)							\
>+	*(.gnu.version*)						\
> 	}
>
> /**
>-- 
>2.25.1

I wonder what lead to .gnu.version{,_d,_r} sections in the kernel.

tools/lib/bpf/libbpf_internal.h uses `.symver` directive and
-Wl,--version-script, which may lead to .gnu.version{,_d}, but this only
applies to the userspace libbpf.so

libperf.so has a similar -Wl,--version-script.

Linking vmlinux does not appear to use any symbol versioning.