[cherry-pick] [ELF] --emit-relocs: adjust offsets of .rel[a].eh_frame relocations #134
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* Improve eh-frame-merge.s * Delete invalid .eh_frame+5 test in ehframe-relocation.s
Two code paths may reach the EHFrame case in SectionBase::getOffset: * .eh_frame reference * relocation copy for --emit-relocs The first may be used by clang_rt.crtbegin.o and GCC crtbeginT.o to get the start address of the output .eh_frame. The relocation has an offset of 0 or (x86-64 PC-relative leaq for clang_rt.crtbegin.o) -4. The current code just returns `offset`, which handles this case well. The second is related to InputSection::copyRelocations on .eh_frame (used by --emit-relocs). .eh_frame pieces may be dropped due to GC/ICF, so we should convert the input offset to the output offset. Use the same way as MergeInputSection with a special case handling outSecOff==-1 for an invalid piece (see eh-frame-marker.s). This exposes an issue in mips64-eh-abs-reloc.s that we don't reliably handle anyway. Just add --no-check-dynamic-relocations to paper over it. Differential Revision: https://reviews.llvm.org/D122459
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Does this have/need a 14.0.x backport? |
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This doesn't have an upstream backport. I don't think it would benefit from one since the |
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I was mainly wondering because the change doesn't really look mipsel-sony-psp specific at a cursory glance. But if an upstream backport doesn't seem useful, let's just merge it here... |
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Namespace enums in the serialiser.
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This patch fixes the offsets of .rel[a].eh_frame relocations emitted by lld. That fixes catching panics for the
mipsel-sony-psptarget which defaults to lld and relies on-Wl,--emit-relocsemitting correct relocations. Catching panics is still broken for the PSP when gc-sections in on, but that requires further fixes in upstream lld.I included a commit that refactored related tests to avoid manually fixing cherry-pick conflicts and cherry-picked only the final fix since my original fix was briefly reverted then reimplemented correctly. See the review for more details. https://reviews.llvm.org/D122459
cc @overdrivenpotato