[PATCH] D126898: [COFF] Check table ptr more thoroughly and ignore empty sections

[Mike Hommey via Phabricator via llvm-commits]

glandium added a comment.

> The base relocation table usually resides in the .reloc section, and as the exact size (0xB68) matches, it looks like it just has got the wrong RVA in the header. With the new, more thorough checks, libObject notices that the RVA points into the .ndata section (within 0x40000 - 0x5C000) but there's only raw data covering 0x40000 - 0x40200, and 0x43000 is outside of that. Previously we'd just set up a pointer into bogus/out of range data in these cases, now we error out.

>From a cursory look, it seems to come from NSIS itself not handing BaseRelocationTableRVA. Its prebuild binaries come with stubs that actually have it set to 0 and thus don't have a .reloc section. The stubs we're using in the case of that helper.exe were compiled with mingw-clang and linked with mingw-lld, and do contain a .reloc section. The helper.exe binary ends up having the same BaseRelocationTableRVA as the stub, but NSIS moved the .reloc section, so it's not correct anymore.

So... maybe you shouldn't actually relax things as per D127345 <https://reviews.llvm.org/D127345>, because it seems like a genuine bug in NSIS that should be fixed rather than worked around.


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  https://reviews.llvm.org/D126898/new/

https://reviews.llvm.org/D126898