Search code examples
macosclangllvmaddress-sanitizer

How to make AddressSanitizer not stop after one error (and other issues)

I'm running OS X, 10.8.5; I've installed llvm 3.4 via homebrew (clang version 3.4 (tags/RELEASE_34/final) ), and I'm building with -fsanitize=address. I can get asan working with simple demo programs, but when building against our codebase, I have several problems (although I'd really just like an answer to #1):

  1. 3rd party libraries are generating asan errors, and asan is terminating my app on the first occurrence. I would think that there would be some kind of (runtime/compile-time) option to tell asan to keep going after finding an error. Specifically, I see this:
bash-3.2$ ASAN_SYMBOLIZER_PATH=/usr/local/Cellar/llvm34/3.4/lib/llvm-3.4/bin/llvm-symbolizer ./unit_test
Start testing of PathTrieTest
Config: Using QTest library 4.8.2, Qt 4.8.2
PASS   : PathTrieTest::initTestCase()
PASS   : PathTrieTest::pathTrieNodeTest()

=================================================================
==76647==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61600019e588 at pc 0x10891ddd3 bp 0x11312ba90 sp 0x11312ba58
WRITE of size 48830 at 0x61600019e588 thread T3
    #0 0x10891ddd2 in wrap_readdir_r (/usr/local/lib/llvm-3.4/lib/clang/3.4/lib/darwin/libclang_rt.asan_osx_dynamic.dylib+0x11dd2)
    #1 0x10ac23571 in QFileSystemIterator::advance(QFileSystemEntry&, QFileSystemMetaData&) (/Volumes/ToolChain/qt-4.8/lib/QtCore.framework/Versions/4/QtCore+0xef571)
    #2 0x10abd86d3 in QDirIteratorPrivate::advance() (/Volumes/ToolChain/qt-4.8/lib/QtCore.framework/Versions/4/QtCore+0xa46d3)
    #3 0x10abd7a7f in QDirIteratorPrivate::QDirIteratorPrivate(QFileSystemEntry const&, QStringList const&, QFlags<QDir::Filter>, QFlags<QDirIterator::IteratorFlag>, bool) (/Volumes/ToolChain/qt-4.8/lib/QtCore.framework/Versions/4/QtCore+0xa3a7f)
    #4 0x10abd8b68 in QDirIterator::QDirIterator(QDir const&, QFlags<QDirIterator::IteratorFlag>) (/Volumes/ToolChain/qt-4.8/lib/QtCore.framework/Versions/4/QtCore+0xa4b68)
    #5 0x10abd7609 in QDirPrivate::initFileLists(QDir const&) const (/Volumes/ToolChain/qt-4.8/lib/QtCore.framework/Versions/4/QtCore+0xa3609)
    #6 0x10abd5394 in QDir::count() const (/Volumes/ToolChain/qt-4.8/lib/QtCore.framework/Versions/4/QtCore+0xa1394)
    #7 0x1084c205d in get_count(QFileInfo&) /Users/stebro/dev_vm/ui/ui/fsinfoprovider.cpp:36
...

This error doesn't cause the app to terminate when it's running unsanitized.

  1. I can't get code to link when using the -fsanitize=undefined (or -fsanitize=address,undefined) options. I am including the -fsanitize=undefined line on both my compile & link commands, but I get link errors such as:

       Undefined symbols for architecture x86_64:
     "typeinfo for __cxxabiv1::__class_type_info", referenced from:
         __ubsan::checkDynamicType(void*, void*, unsigned long) in libclang_rt.ubsan_osx.a(ubsan_type_hash.o)
         isDerivedFromAtOffset(__cxxabiv1::__class_type_info const*, __cxxabiv1::__class_type_info const*, long) in libclang_rt.ubsan_osx.a(ubsan_type_hash.o)
         findBaseAtOffset(__cxxabiv1::__class_type_info const*, long) in libclang_rt.ubsan_osx.a(ubsan_type_hash.o)
   "typeinfo for __cxxabiv1::__si_class_type_info", referenced from:
         isDerivedFromAtOffset(__cxxabiv1::__class_type_info const*, __cxxabiv1::__class_type_info const*, long) in libclang_rt.ubsan_osx.a(ubsan_type_hash.o)
         findBaseAtOffset(__cxxabiv1::__class_type_info const*, long) in libclang_rt.ubsan_osx.a(ubsan_type_hash.o)
   "typeinfo for __cxxabiv1::__vmi_class_type_info", referenced from:
         isDerivedFromAtOffset(__cxxabiv1::__class_type_info const*, __cxxabiv1::__class_type_info const*, long) in libclang_rt.ubsan_osx.a(ubsan_type_hash.o)
         findBaseAtOffset(__cxxabiv1::__class_type_info const*, long) in libclang_rt.ubsan_osx.a(ubsan_type_hash.o)

  2. I can't get blacklists to work, and -mllvm -asan-globals=0 or -mllvm -asan-stack=0 doesn't seem to work like I'd expect. For example, the latter don't suppress the generation of the error listed in #1 above, and creating a blacklist that looks like the one below doesn't suppress the errors either:

    fun:QDirPrivate::initFileLists fun:get_count fun:opendir2

  3. Finally, executables generated with these asan options cause lldb to crash. I'm using the lldb shipped with XCode 5 tools; there was no lldb deployed with the homebew llvm package, and I can't figure out how to build it. The build instructions enter link description here have a dead link that points to the source you're supposed to use; pulling the source directly from the svn repository, using:

svn co http://llvm.org/svn/llvm-project/lldb/tags/RELEASE_34/final lldb

results in code that doesn't compile (errors provided upon request).

Solution

  • You can build your project with -fsanitize=address -fsanitize-recover=address flags, and run with environment variable ASAN_OPTIONS=halt_on_error=0. Source: https://github.com/google/sanitizers/wiki/AddressSanitizer