labath added a comment.

In D59291#1438053 <https://reviews.llvm.org/D59291#1438053>, @aprantl wrote:

> Looks like this uncovered some UB:
>
> http://lab.llvm.org:8080/green/view/LLDB/job/lldb-sanitized/2050/testReport/junit/lldb-Suite/functionalities_postmortem_minidump-new/TestMiniDumpUUID_py/


I'm pretty sure this was caused by https://reviews.llvm.org/D59433 and not by 
this patch because LLDB does not use this code (yet).

Incidentally, just today I was working on adding string reading to the llvm 
parser, and noticed this potential misaligned access in lldb code. I don't 
think it can ever occur in practice for real (valid) minidumps, because those 
will have those fields correctly aligned, but I believe the reason that patch 
caught this problem is that the hand-crafted minidumps Greg created did not 
respect the natural alignment of the types. I think the fix is to regenerate 
the minidump binaries to correctly align the string fields, and also teach the 
lldb string reader to reject misaligned strings. The second part may not be so 
important, as I am going to delete that code soon anyway.

Alternatively, we could teach the lldb string reader to handle the misaligned 
strings correctly (most likely by memcpying them into aligned storage)...


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D59291/new/

https://reviews.llvm.org/D59291



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