[PATCH] D109847: [DFSan] Add force_zero_label abilist option to DFSan. This can be used as a work-around for overtainting.

[Matt Morehouse via Phabricator via llvm-commits]

morehouse added a comment.

What's the motivation for this feature?

I think `discard` already returns 0 labels.  When do we also need to store 0 labels?



================
Comment at: compiler-rt/test/dfsan/Inputs/force_zero_abilist.txt:1
-fun:f=uninstrumented
+fun:function_to_force_zero=force_zero_labels
 
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Why a separate abilist.txt?


================
Comment at: compiler-rt/test/dfsan/force_zero.c:25
+  assert(dfsan_get_label(out) == 0);
+  assert(dfsan_get_label(ret) == 0);
+#else
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Wouldn't this also pass if we used `uninstrumented` or `discard` in the ABI list?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D109847/new/

https://reviews.llvm.org/D109847