diff options
author | Eric Fiselier <eric@efcs.ca> | 2015-03-10 23:43:34 +0300 |
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committer | Eric Fiselier <eric@efcs.ca> | 2015-03-10 23:43:34 +0300 |
commit | e6cdf34116305bae21caeff1738625ce375bc196 (patch) | |
tree | 7b154bc1f9ac0d049048a17475b638ef126c6482 /libcxxabi/src/cxa_personality.cpp | |
parent | 8f6a115de96dcb777d388dd95efcd40d4139421e (diff) |
[libcxx] Fix PR21580 - Undefined behavior in readEncodedPointer()
Summary: This patch fixes a bug in `readEncodedPointer()` where it would read from memory that was not suitably aligned. This patch fixes it by using memcpy.
Reviewers: danalbert, echristo, compnerd, mclow.lists
Reviewed By: compnerd, mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D8179
llvm-svn: 231839
Diffstat (limited to 'libcxxabi/src/cxa_personality.cpp')
-rw-r--r-- | libcxxabi/src/cxa_personality.cpp | 32 |
1 files changed, 20 insertions, 12 deletions
diff --git a/libcxxabi/src/cxa_personality.cpp b/libcxxabi/src/cxa_personality.cpp index 3ea8ca34c3f3..24838f428f4c 100644 --- a/libcxxabi/src/cxa_personality.cpp +++ b/libcxxabi/src/cxa_personality.cpp @@ -14,6 +14,7 @@ #include <assert.h> #include <stdlib.h> +#include <string.h> #include <typeinfo> #include "config.h" @@ -141,6 +142,19 @@ Notes: namespace __cxxabiv1 { +namespace +{ + +template <class AsType> +uintptr_t readPointerHelper(const uint8_t*& p) { + AsType value; + memcpy(&value, const_cast<uint8_t*>(p), sizeof(AsType)); + p += sizeof(AsType); + return static_cast<uintptr_t>(value); +} + +} // end namespace + extern "C" { @@ -245,28 +259,22 @@ readEncodedPointer(const uint8_t** data, uint8_t encoding) result = static_cast<uintptr_t>(readSLEB128(&p)); break; case DW_EH_PE_udata2: - result = *((uint16_t*)p); - p += sizeof(uint16_t); + result = readPointerHelper<uint16_t>(p); break; case DW_EH_PE_udata4: - result = *((uint32_t*)p); - p += sizeof(uint32_t); + result = readPointerHelper<uint32_t>(p); break; case DW_EH_PE_udata8: - result = static_cast<uintptr_t>(*((uint64_t*)p)); - p += sizeof(uint64_t); + result = readPointerHelper<uint64_t>(p); break; case DW_EH_PE_sdata2: - result = static_cast<uintptr_t>(*((int16_t*)p)); - p += sizeof(int16_t); + result = readPointerHelper<int16_t>(p); break; case DW_EH_PE_sdata4: - result = static_cast<uintptr_t>(*((int32_t*)p)); - p += sizeof(int32_t); + result = readPointerHelper<int32_t>(p); break; case DW_EH_PE_sdata8: - result = static_cast<uintptr_t>(*((int64_t*)p)); - p += sizeof(int64_t); + result = readPointerHelper<int64_t>(p); break; default: // not supported |