[all-commits] [llvm/llvm-project] 163a9f: [MSan] Ensure argument shadow initialized on memcpy

[Vitaly Buka via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 163a9f4552bea71b2d53126a5f74f9a1b47d2865
      https://github.com/llvm/llvm-project/commit/163a9f4552bea71b2d53126a5f74f9a1b47d2865
  Author: Vitaly Buka <vitalybuka at google.com>
  Date:   2022-04-12 (Tue, 12 Apr 2022)

  Changed paths:
    M llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
    A llvm/test/Instrumentation/MemorySanitizer/opaque-ptr.ll

  Log Message:
  -----------
  [MSan] Ensure argument shadow initialized on memcpy

We need to explicitly query the shadow here, because it is lazily
initialized for byval arguments. Without opaque pointers this used to
mostly work out, because there would be a bitcast to `i8*` present, and
that would query, and copy in case of byval, the argument shadow.

Reviewed By: vitalybuka, eugenis

Differential Revision: https://reviews.llvm.org/D123602