[PATCH] D119384: [MTE] [lld] Add --memtag-* options to synthetise ELF notes.

[Peter Smith via Phabricator via llvm-commits]

peter.smith added a comment.

Some initial thoughts.

- If this is likely to be rolled out to other platforms such as Linux/BSD etc. It would be useful to have something common written up in the ABI. As MaskRay suggests the best way forward would be to raise an issue or a pull request https://github.com/ARM-software/abi-aa . You are of course welcome to implement an Android specific platform ABI, but it would be good to a similar one across multiple platforms if possible.
- For BTI, for better or worse, we chose to  https://github.com/ARM-software/abi-aa/blob/main/aaelf64/aaelf64.rst#62program-property as this mechanism was going to be needed for Intel platforms. Ideally this would be documented in the SysVABI doc, but that didn't exist at the time the property was created.
- Do you need per-object marking that a linker will aggregate? For example do you enable when at least one object needs MTE, or do you need all objects to be compatible with MTE? A per object marking that can be overridden at link time will give you a chance to diagnose objects that may not have the MTE support. It can help to have an assembler option to fabricate the note if objects are used.
- A colleague mentioned that the choice of command line options were quite generic. If they are aarch64 and Android specific they probably ought to be behind -z and perhaps with AArch64 and Android in the name.


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https://reviews.llvm.org/D119384