[PATCH] D117285: [msan] Copy origin of byval arguments

[Evgenii Stepanov via Phabricator via llvm-commits]

eugenis accepted this revision.
eugenis added a comment.
This revision is now accepted and ready to land.

LGTM

A compiler-rt test for origin propagation would be great.



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Comment at: llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp:1741
+                    getOriginPtrForArgument(&FArg, EntryIRB, ArgOffset);
+                EntryIRB.CreateMemCpy(CpOriginPtr, CopyAlign, OriginPtr,
+                                      CopyAlign, Size);
----------------
This can get weird if the byval pointer is less than 4 byte aligned, but the alternatives are not pretty, either.

Also, you can bump the alignment `std::max(CopyAlign, kMinOriginAlignment)`.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D117285/new/

https://reviews.llvm.org/D117285