Task 194243

src/ldo.c

@@ -69,10 +69,23 @@ void luaD_throw (lua_State *L, int errcode) {
     LUAI_THROW(L, L->errorJmp);
   }
   else {
+    thrlua_log(L, DCRITICAL,
+      "luaD_throw: no error handler, errcode=%d, L=%p, invoking panic",
+      errcode, (void *)L);
     L->status = cast_byte(errcode);
     if (G(L)->panic) {
       resetstack(L, errcode);
-      lua_unlock(L);
+      /* Do NOT call lua_unlock(L) here.  When luaD_throw is reached
+       * via LUAI_TRY_END re-throw, the LUAI_TRY_FINALLY block has
+       * already run and the lock state depends on the call site:
+       * some FINALLY blocks call lua_unlock (lapi.c, lauxlib.c) while
+       * others call lua_lock (ldo.c callhook/precall).  Unconditionally
+       * unlocking here caused a double-unlock that corrupted the
+       * pthread mutex on Linux/glibc, making every subsequent
+       * lua_lock() on this lua_State fail with EINVAL and abort().
+       * All direct callers of luaD_throw (lmem.c, ldebug.c, lundump.c,
+       * llex.c) always have an outer errorJmp so they never reach
+       * this panic branch. */
       G(L)->panic(L);
     }
     exit(EXIT_FAILURE);

src/thrlua.h

@@ -254,6 +254,12 @@ extern void lua_do_longjmp(luai_jmpbuf env, int val)
 #define LUAI_TRY_END(L) \
   (L)->errorJmp = lj.previous; \
   if (lj.status) { \
+    /* Log the error and re-throw path for diagnostics. */ \
+    thrlua_log((L), DCRITICAL, \
+      "LUAI_TRY_END: error status=%d in TRY block at %s:%d, " \
+      "re-throwing with %s outer handler, L=%p", \
+      lj.status, lj.file, lj.line, \
+      lj.previous ? "an" : "NO", (void *)(L)); \
     luaD_throw((L), lj.status); \
   } \
 } while(0)