[PATCH] D128998: [libunwind] Handle G in personality string

[Florian Mayer via Phabricator via llvm-commits]

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fix unused argument error


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format


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fix mingw build


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build


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clang fmt


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fix build


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comment


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update comment


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In addition to the test described in the message, I ran the libunwind test suites on FVP with SANITIZE_TARGET=memtag-stack and they still pass.


Tested with the following program:

  static volatile int* x = nullptr;
  
  void throws()  __attribute__((noinline)) {
    if (getpid() == 0)
      return;
    throw "error";
  }
  
  void maybe_throws()  __attribute__((noinline)) {
    volatile int y = 1;
    x = &y;
    throws();
    y = 2;
  }
  
  int main(int argc, char** argv) {
    int y;
    try {
      maybe_throws();
    } catch (const char* e) {
      //printf("Caught\n");
    }
    y = *x;
    printf("%d\n", y); // should be MTE failure.
    return 0;
  }

Without this change, we crash on cxa_get_globals when trying to catch
the exception (because the stack frame hadn't been cleared up). With
this change, we crash on the `y = *x;` as expected, because the stack
frame has been untagged, but the pointer hasn't.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D128998

Files:
  libunwind/src/DwarfInstructions.hpp
  libunwind/src/DwarfParser.hpp
  libunwind/src/UnwindCursor.hpp
  libunwind/src/UnwindLevel1.c
  libunwind/src/libunwind.cpp
  libunwind/src/libunwind_ext.h

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