[PATCH] D23107: [MSAN][MIPS] Fix fork.cc test on MIPS

[Evgeniy Stepanov via llvm-commits]

eugenis added a comment.

Good catch!
So, the slow unwinder is not async signal safe. This makes _any_ store of uninit value not async signal safe with chained-origins on platforms w/o the fast unwinder (mips, sparc).

I think we should play it safe and disable the slow unwinder in __msan_chain_origin. If there is no fast unwinder for the platform, the next best thing would be reducing store_context_size to 1 (or is it 0? basically, just recording the current PC). This would not be great for the user experience, but the alternative is random freezes in forking applications as well as in signal handlers.


Repository:
  rL LLVM

https://reviews.llvm.org/D23107