[PATCH] D58195: [HWASAN] Updated HWASAN design document to better portray the chance of missing a bug.

[Mitch Phillips via Phabricator via cfe-commits]

hctim created this revision.
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Provided rule of thumb percentage chances of miss for 4 and 8 bit tag sizes.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D58195

Files:
  clang/docs/HardwareAssistedAddressSanitizerDesign.rst


Index: clang/docs/HardwareAssistedAddressSanitizerDesign.rst
===================================================================
--- clang/docs/HardwareAssistedAddressSanitizerDesign.rst
+++ clang/docs/HardwareAssistedAddressSanitizerDesign.rst
@@ -131,7 +131,8 @@
     https://www.kernel.org/doc/Documentation/arm64/tagged-pointers.txt).
   * **Does not require redzones to detect buffer overflows**,
     but the buffer overflow detection is probabilistic, with roughly
-    `(2**TS-1)/(2**TS)` probability of catching a bug.
+    `1/(2**TS)` chance of missing a bug (6.25% or 0.39% with 4 and 8-bit TS
+    respectively).
   * **Does not require quarantine to detect heap-use-after-free,
     or stack-use-after-return**.
     The detection is similarly probabilistic.


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