Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 1 Sep 2020 10:16:47 +0200
From:   Ingo Molnar <mingo@kernel.org>
To:     Kees Cook <keescook@chromium.org>
Cc:     Borislav Petkov <bp@suse.de>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Ard Biesheuvel <ardb@kernel.org>,
        Peter Collingbourne <pcc@google.com>,
        James Morse <james.morse@arm.com>,
        Ingo Molnar <mingo@redhat.com>,
        Russell King <linux@armlinux.org.uk>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Arvind Sankar <nivedita@alum.mit.edu>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nathan Chancellor <natechancellor@gmail.com>,
        Arnd Bergmann <arnd@arndb.de>, x86@kernel.org,
        clang-built-linux@googlegroups.com, linux-arch@vger.kernel.org,
        linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 00/29] Warn on orphan section placement
Message-ID: <20200901081647.GB3602433@gmail.com>
References: <20200821194310.3089815-1-keescook@chromium.org>
 <202008311240.9F94A39@keescook>
 <20200901071133.GA3577996@gmail.com>
 <20200901075937.GA3602433@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200901075937.GA3602433@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


* Ingo Molnar <mingo@kernel.org> wrote:

> 
> * Ingo Molnar <mingo@kernel.org> wrote:
> 
> > 
> > * Kees Cook <keescook@chromium.org> wrote:
> > 
> > > On Fri, Aug 21, 2020 at 12:42:41PM -0700, Kees Cook wrote:
> > > > Hi Ingo,
> > > > 
> > > > Based on my testing, this is ready to go. I've reviewed the feedback on
> > > > v5 and made a few small changes, noted below.
> > > 
> > > If no one objects, I'll pop this into my tree for -next. I'd prefer it
> > > go via -tip though! :)
> > > 
> > > Thanks!
> > 
> > I'll pick it up today, it all looks very good now!
> 
> One thing I found in testing is that it doesn't handler older LD 
> versions well enough:
> 
>   ld: unrecognized option '--orphan-handling=warn'
> 
> Could we just detect the availability of this flag, and emit a warning 
> if it doesn't exist but otherwise not abort the build?
> 
> This is with:
> 
>   GNU ld version 2.25-17.fc23

I've resolved this for now by not applying the 5 patches that add the 
actual orphan section warnings:

  arm64/build: Warn on orphan section placement
  arm/build: Warn on orphan section placement
  arm/boot: Warn on orphan section placement
  x86/build: Warn on orphan section placement
  x86/boot/compressed: Warn on orphan section placement

The new asserts plus the actual fixes/enhancements are enough changes 
to test for now in any case. :-)

Thanks,

	Ingo