Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [PATCH v9 0/6] add support for relative references in special sections | Date | Wed, 27 Jun 2018 15:33:44 +1000 |
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Ard Biesheuvel <ard.biesheuvel@linaro.org> writes: > This adds support for emitting special sections such as initcall arrays, > PCI fixups and tracepoints as relative references rather than absolute > references. This reduces the size by 50% on 64-bit architectures, but > more importantly, it removes the need for carrying relocation metadata > for these sections in relocatable kernels (e.g., for KASLR) that needs > to be fixed up at boot time. On arm64, this reduces the vmlinux footprint > of such a reference by 8x (8 byte absolute reference + 24 byte RELA entry > vs 4 byte relative reference) ... > > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Kees Cook <keescook@chromium.org> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Michael Ellerman <mpe@ellerman.id.au>
This seems to be working on powerpc.
It boots on a couple of machines with no obvious badness.
And there's some size reduction with a random config I had lying around:
Total: Before=14820494, After=14673313, chg -0.99%
It can get some more testing once it's in linux-next as far as I'm concerned.
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
cheers
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