replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Reimplement Thread Static Data ASan routines with TLS 

Summary:
Thread Static Data cannot be used in early init on NetBSD
and FreeBSD. Reuse the ASan TSD API for compatibility with
existing code with an alternative implementation using Thread
Local Storage.

New version uses Thread Local Storage to store a pointer
with thread specific data. The destructor from TSD has been
replaced with a TLS destrucutor that is called upon thread
exit.

Reviewers: joerg, vitalybuka, jfb

Reviewed By: vitalybuka

Subscribers: dim, emaste, ro, jfb, devnexen, kubamracek, mgorny, llvm-commits, #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D55596

llvm-svn: 349619
This commit is contained in:
Kamil Rytarowski 2018-12-19 11:11:29 +00:00
parent dd67793c0c
commit 342d03e71f
1 changed files with 46 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
compiler-rt/lib/asan/asan_posix.cc
View File

@ -40,6 +40,51 @@ void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
// ---------------------- TSD ---------------- {{{1
#if SANITIZER_NETBSD || SANITIZER_FREEBSD
// Thread Static Data cannot be used in early init on NetBSD and FreeBSD.
// Reuse the Asan TSD API for compatibility with existing code
// with an alternative implementation.
static void (*tsd_destructor)(void *tsd) = nullptr;
struct tsd_key {
tsd_key() : key(nullptr) {}
~tsd_key() {
CHECK(tsd_destructor);
if (key)
(*tsd_destructor)(key);
}
void *key;
};
static thread_local struct tsd_key key;
void AsanTSDInit(void (*destructor)(void *tsd)) {
CHECK(!tsd_destructor);
tsd_destructor = destructor;
}
void *AsanTSDGet() {
CHECK(tsd_destructor);
return key.key;
}
void AsanTSDSet(void *tsd) {
CHECK(tsd_destructor);
CHECK(tsd);
CHECK(!key.key);
key.key = tsd;
}
void PlatformTSDDtor(void *tsd) {
CHECK(tsd_destructor);
CHECK_EQ(key.key, tsd);
key.key = nullptr;
// Make sure that signal handler can not see a stale current thread pointer.
atomic_signal_fence(memory_order_seq_cst);
AsanThread::TSDDtor(tsd);
}
#else
static pthread_key_t tsd_key;
static bool tsd_key_inited = false;
void AsanTSDInit(void (*destructor)(void *tsd)) {
@ -67,6 +112,7 @@ void PlatformTSDDtor(void *tsd) {
}
AsanThread::TSDDtor(tsd);
}
#endif
} // namespace __asan
#endif // SANITIZER_POSIX