[PATCH] D104184: [Coroutine] Put byval params' value into frame, instead of just pointer

[Xun Li via Phabricator via llvm-commits]

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This patch is to address https://bugs.llvm.org/show_bug.cgi?id=48857.
A previous attemp is in D104007 <https://reviews.llvm.org/D104007>.
If a parameter needs to live across coroutine suspensions, we put the parameter on the coroutine frame.
However for byval parameters, it's insufficient to just put the parameter itself on the frame, because byval param is essentially like an alloca where the memory belongs to this coroutine.
We need to treat them like allocas, and put their value content in the frame, instead of just the parameter pointer.
This will fix the bug where memcpy from a byval param to a local alloca triggers memory use-after-free after a coroutien suspension.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D104184

Files:
  llvm/lib/Transforms/Coroutines/CoroFrame.cpp
  llvm/test/Transforms/Coroutines/coro-byval-param.ll

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