Messages in this thread | | | Date | Wed, 26 Jun 2019 11:32:10 +0100 | From | Will Deacon <> | Subject | Re: [PATCH] arm64/efi: Mark __efistub_stext_offset as an absolute symbol explicitly |
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On Wed, Jun 26, 2019 at 09:07:00AM +0200, Ard Biesheuvel wrote: > On Wed, 26 Jun 2019 at 06:20, Nathan Chancellor > <natechancellor@gmail.com> wrote: > > > > After r363059 and r363928 in LLVM, a build using ld.lld as the linker > > with CONFIG_RANDOMIZE_BASE enabled fails like so: > > > > ld.lld: error: relocation R_AARCH64_ABS32 cannot be used against symbol > > __efistub_stext_offset; recompile with -fPIC > > > > Fangrui and Peter figured out that ld.lld is incorrectly considering > > __efistub_stext_offset as a relative symbol because of the order in > > which symbols are evaluated. _text is treated as an absolute symbol > > and stext is a relative symbol, making __efistub_stext_offset a > > relative symbol. > > > > Adding ABSOLUTE will force ld.lld to evalute this expression in the > > right context and does not change ld.bfd's behavior. ld.lld will > > need to be fixed but the developers do not see a quick or simple fix > > without some research (see the linked issue for further explanation). > > Add this simple workaround so that ld.lld can continue to link kernels. > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/561 > > Link: https://github.com/llvm/llvm-project/commit/025a815d75d2356f2944136269aa5874721ec236 > > Link: https://github.com/llvm/llvm-project/commit/249fde85832c33f8b06c6b4ac65d1c4b96d23b83 > > Debugged-by: Fangrui Song <maskray@google.com> > > Debugged-by: Peter Smith <peter.smith@linaro.org> > > Suggested-by: Fangrui Song <maskray@google.com> > > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> > > Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Thanks. I'll pick this up and add the link to the Clang issue as a comment in the header.
Will
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