linux-kernel - Re: [PATCH v2 1/2] kbuild: Hoist '--orphan-handling' into Kconfig

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: <202011201607.75FA476@keescook>
Date:   Fri, 20 Nov 2020 16:08:43 -0800
From:   Kees Cook <keescook@...omium.org>
To:     Masahiro Yamada <masahiroy@...nel.org>
Cc:     Nathan Chancellor <natechancellor@...il.com>,
        Michal Marek <michal.lkml@...kovi.net>,
        Russell King <linux@...linux.org.uk>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        x86@...nel.org, Nick Desaulniers <ndesaulniers@...gle.com>,
        Arvind Sankar <nivedita@...m.mit.edu>,
        linux-kernel@...r.kernel.org, linux-kbuild@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linuxppc-dev@...ts.ozlabs.org, clang-built-linux@...glegroups.com
Subject: Re: [PATCH v2 1/2] kbuild: Hoist '--orphan-handling' into Kconfig

On Thu, Nov 19, 2020 at 01:46:56PM -0700, Nathan Chancellor wrote:
> Currently, '--orphan-handling=warn' is spread out across four different
> architectures in their respective Makefiles, which makes it a little
> unruly to deal with in case it needs to be disabled for a specific
> linker version (in this case, ld.lld 10.0.1).
> 
> To make it easier to control this, hoist this warning into Kconfig and
> the main Makefile so that disabling it is simpler, as the warning will
> only be enabled in a couple places (main Makefile and a couple of
> compressed boot folders that blow away LDFLAGS_vmlinx) and making it
> conditional is easier due to Kconfig syntax. One small additional
> benefit of this is saving a call to ld-option on incremental builds
> because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN.
> 
> To keep the list of supported architectures the same, introduce
> CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to
> gain this automatically after all of the sections are specified and size
> asserted. A special thanks to Kees Cook for the help text on this
> config.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/1187
> Acked-by: Kees Cook <keescook@...omium.org>
> Acked-by: Michael Ellerman <mpe@...erman.id.au> (powerpc)
> Reviewed-by: Nick Desaulniers <ndesaulniers@...gle.com>
> Tested-by: Nick Desaulniers <ndesaulniers@...gle.com>
> Signed-off-by: Nathan Chancellor <natechancellor@...il.com>

Masahiro, do you want to take these to get them to Linus for v5.10? I
can send them if you'd prefer.

-Kees

-- 
Kees Cook