[libcxx-commits] [PATCH] D83742: [libunwind] Fix getSLEB128 on large values

[Ryan Prichard via Phabricator via libcxx-commits]

rprichard updated this revision to Diff 277668.
rprichard added a comment.

The shift for negative numbers is also broken.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D83742/new/

https://reviews.llvm.org/D83742

Files:
  libunwind/src/AddressSpace.hpp


Index: libunwind/src/AddressSpace.hpp
===================================================================
--- libunwind/src/AddressSpace.hpp
+++ libunwind/src/AddressSpace.hpp
@@ -290,11 +290,11 @@
     if (p == pend)
       _LIBUNWIND_ABORT("truncated sleb128 expression");
     byte = *p++;
-    result |= ((byte & 0x7f) << bit);
+    result |= (uint64_t)(byte & 0x7f) << bit;
     bit += 7;
   } while (byte & 0x80);
   // sign extend negative numbers
-  if ((byte & 0x40) != 0)
+  if ((byte & 0x40) != 0 && bit < 64)
     result |= (-1ULL) << bit;
   addr = (pint_t) p;
   return result;


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