[PATCH] D68720: Support -fstack-clash-protection for x86

[serge via Phabricator via llvm-commits]

serge-sans-paille added a comment.

> For maintenance reasons, I'd really prefer it if we could find a way to reuse the existing code that calls an external stack probe function. What do you think about taking a look at X86RetpolineThunks.cpp and doing something similar to that? Basically, when the user sets -fstack-clash-protection, LLVM will emit a small comdat+weak function into every object file that has the same ABI as the existing stack probe mechanism. For other prior art, you can also look at how __clang_call_terminate works.

@rnk I 100% understand the reasoning, and will have a look to the files you're pointing at. AFAIU the approach you're suggesting is incompatible with the « free probe » algorithm that moves instruction in between stack allocations, but let me confirm that first.


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  https://reviews.llvm.org/D68720/new/

https://reviews.llvm.org/D68720