| Issue |
71711
|
| Summary |
[AMDGPU] Linking with FatBinary files disables stack execution protection
|
| Labels |
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| Assignees |
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| Reporter |
AngryLoki
|
After `constructGenerateObjFileFromHIPFatBinary` at https://github.com/llvm/llvm-project/blob/main/clang/lib/Driver/ToolChains/HIPUtility.cpp#L137, llvm-mc is used to generate an object file, which is linked into an executable/library file as a part of hipcc -> clang -> ld chain call. And as mcin file has no GNU-stack section, the entire library gets marked for an executable stack[1].
I discovered this as a result of warning in Gentoo[2], as a chain for rccl-5.7.1 compilation. The whole chain there is hipcc -> clang 17.0.3 -> [clang-offload-bundler + lld + llvm-mc + x86_64-pc-linux-gnu-ld.bfd], which eventually completes with
```
/usr/bin/x86_64-pc-linux-gnu-ld.bfd: warning: /tmp/bootstrap-29289b.o: missing .note.GNU-stack section implies executable stack
/usr/bin/x86_64-pc-linux-gnu-ld.bfd: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
The following files contain writable and executable sections
...
RWX --- --- usr/lib64/librccl.so.1.0
```
I hope this describes the issue clear enough; attaching compilation log (huge!) won't help, because underlying commands are not even visible there (but visible with `-###`).
I can additionally mention, that https://github.com/ROCm-Developer-Tools/clr/issues/22 has similar issue: mcin file includes fatbin, the difference is that they use cmake to generate mcin file (I understand that the problem in clr is separate, but it is _thematically related_).
Could you add `.note.GNU-stack` in constructGenerateObjFileFromHIPFatBinary or provide any other solution? Thanks!
[1] https://wiki.ubuntu.com/SecurityTeam/Roadmap/ExecutableStacks
[2] https://wiki.gentoo.org/wiki/Hardened/GNU_stack_quickstart
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