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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Tue, 25 Feb 2020 12:37:26 -0800
Message-ID: <CAKwvOdnkr1W4LTm8XmTKGkSDUhSBRowLbKwJwyitDMAGLh9ywg@mail.gmail.com>
Subject: Re: --orphan-handling=warn
To:     Kees Cook <keescook@chromium.org>
Cc:     Arvind Sankar <nivedita@alum.mit.edu>,
        Fangrui Song <maskray@google.com>,
        Borislav Petkov <bp@alien8.de>,
        Nathan Chancellor <natechancellor@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        Michael Matz <matz@suse.de>,
        Kristen Carlson Accardi <kristen@linux.intel.com>
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On Tue, Feb 25, 2020 at 11:43 AM Kees Cook <keescook@chromium.org> wrote:
>
> On Tue, Feb 25, 2020 at 01:29:51PM -0500, Arvind Sankar wrote:
> > On Mon, Feb 24, 2020 at 09:35:04PM -0800, Kees Cook wrote:
> > > Note that cheating and doing the 1-to-1 mapping by handy with a 40,000
> > > entry linker script ... made ld.lld take about 15 minutes to do the
> > > final link. :(
> >
> > Out of curiosity, how long does ld.bfd take on that linker script :)
>
> A single CPU at 100% for 15 minutes. :)

I can see the implementers of linker script handling thinking "surely
no one would ever have >10k entries." Then we invented things like
-ffunction-sections, -fdata-sections, (per basic block equivalents:
https://reviews.llvm.org/D68049) and then finally FGKASLR. "640k ought
to be enough for anybody" and such.
-- 
Thanks,
~Nick Desaulniers