Merge #19337: sync: detect double lock from the same thread

95975dd08d8fdaaeaf28e0d06b861ce2748c17b6 sync: detect double lock from the same thread (Vasil Dimov)
4df6567e4cbb4677e8048de2f8008612e1b860b9 sync: make EnterCritical() & push_lock() type safe (Vasil Dimov)

Pull request description:

  Double lock of the same (non-recursive) mutex from the same thread would produce an undefined behavior. Detect this from `DEBUG_LOCKORDER` and react similarly to the deadlock detection.

  This came up during discussion in another, related PR: https://github.com/bitcoin/bitcoin/pull/19238#discussion_r442394521.

ACKs for top commit:
  laanwj:
    code review ACK 95975dd08d8fdaaeaf28e0d06b861ce2748c17b6
  hebasto:
    re-ACK 95975dd08d8fdaaeaf28e0d06b861ce2748c17b6

Tree-SHA512: 375c62db7819e348bfaecc3bd82a7907fcd8f5af24f7d637ac82f3f16789da9fc127dbd0e37158a08e0dcbba01a55c6635caf1d8e9e827cf5a3747f7690a498e

1 files changed, 8 insertions, 6 deletions

diff --git a/src/sync.h b/src/sync.h
index 41f4e43bdd..0948083c7f 100644
--- a/src/sync.h
+++ b/src/sync.h
@@ -48,7 +48,8 @@ LEAVE_CRITICAL_SECTION(mutex); // no RAII
 ///////////////////////////////
 
 #ifdef DEBUG_LOCKORDER
-void EnterCritical(const char* pszName, const char* pszFile, int nLine, void* cs, bool fTry = false);
+template <typename MutexType>
+void EnterCritical(const char* pszName, const char* pszFile, int nLine, MutexType* cs, bool fTry = false);
 void LeaveCritical();
 void CheckLastCritical(void* cs, std::string& lockname, const char* guardname, const char* file, int line);
 std::string LocksHeld();
@@ -66,7 +67,8 @@ bool LockStackEmpty();
  */
 extern bool g_debug_lockorder_abort;
 #else
-inline void EnterCritical(const char* pszName, const char* pszFile, int nLine, void* cs, bool fTry = false) {}
+template <typename MutexType>
+inline void EnterCritical(const char* pszName, const char* pszFile, int nLine, MutexType* cs, bool fTry = false) {}
 inline void LeaveCritical() {}
 inline void CheckLastCritical(void* cs, std::string& lockname, const char* guardname, const char* file, int line) {}
 template <typename MutexType>
@@ -135,7 +137,7 @@ class SCOPED_LOCKABLE UniqueLock : public Base
 private:
     void Enter(const char* pszName, const char* pszFile, int nLine)
     {
-        EnterCritical(pszName, pszFile, nLine, (void*)(Base::mutex()));
+        EnterCritical(pszName, pszFile, nLine, Base::mutex());
 #ifdef DEBUG_LOCKCONTENTION
         if (!Base::try_lock()) {
             PrintLockContention(pszName, pszFile, nLine);
@@ -148,7 +150,7 @@ private:
 
     bool TryEnter(const char* pszName, const char* pszFile, int nLine)
     {
-        EnterCritical(pszName, pszFile, nLine, (void*)(Base::mutex()), true);
+        EnterCritical(pszName, pszFile, nLine, Base::mutex(), true);
         Base::try_lock();
         if (!Base::owns_lock())
             LeaveCritical();
@@ -205,7 +207,7 @@ public:
 
         ~reverse_lock() {
             templock.swap(lock);
-            EnterCritical(lockname.c_str(), file.c_str(), line, (void*)lock.mutex());
+            EnterCritical(lockname.c_str(), file.c_str(), line, lock.mutex());
             lock.lock();
         }
 
@@ -236,7 +238,7 @@ using DebugLock = UniqueLock<typename std::remove_reference<typename std::remove
 
 #define ENTER_CRITICAL_SECTION(cs)                            \
     {                                                         \
-        EnterCritical(#cs, __FILE__, __LINE__, (void*)(&cs)); \
+        EnterCritical(#cs, __FILE__, __LINE__, &cs); \
         (cs).lock();                                          \
     }