thread mgr: Free aux stack only when it was allocated (#3282)

When thread manager is enabled, the aux stack of exec_env may be allocated
by wasm_cluster_allocate_aux_stack or disabled by setting aux_stack_bottom
as UINTPTR_MAX directly. For the latter, no need to free it.

And fix an issue when paring `--gc-heap-size=n` argument for iwasm, and
fix a variable shadowed warning in fast-jit.

Author: wenyongh

core/iwasm/common/wasm_exec_env.h

@@ -117,6 +117,9 @@ typedef struct WASMExecEnv {
 
     /* whether current thread is detached */
     bool thread_is_detached;
+
+    /* whether the aux stack is allocated */
+    bool is_aux_stack_allocated;
 #endif
 
 #if WASM_ENABLE_GC != 0

core/iwasm/fast-jit/cg/x86-64/jit_codegen_x86_64.cpp

@@ -9293,8 +9293,8 @@ jit_codegen_init()
         imm.setValue(INT32_MAX);
         a.jne(imm);
 
-        char *stream = (char *)a.code()->sectionById(0)->buffer().data()
-                       + a.code()->sectionById(0)->buffer().size();
+        char *stream_old = (char *)a.code()->sectionById(0)->buffer().data()
+                           + a.code()->sectionById(0)->buffer().size();
 
         /* If yes, call jit_set_exception_with_id to throw exception,
            and then set eax to JIT_INTERP_ACTION_THROWN, and jump to
@@ -9319,7 +9319,7 @@ jit_codegen_init()
         /* Patch the offset of jne instruction */
         char *stream_new = (char *)a.code()->sectionById(0)->buffer().data()
                            + a.code()->sectionById(0)->buffer().size();
-        *(int32 *)(stream - 4) = (int32)(stream_new - stream);
+        *(int32 *)(stream_old - 4) = (int32)(stream_new - stream_old);
     }
 
     /* Load compiled func ptr and call it */

core/iwasm/libraries/thread-mgr/thread_manager.c

@@ -558,6 +558,7 @@ wasm_cluster_spawn_exec_env(WASMExecEnv *exec_env)
                                      aux_stack_size)) {
         goto fail3;
     }
+    new_exec_env->is_aux_stack_allocated = true;
 
     /* Inherit suspend_flags of parent thread */
     new_exec_env->suspend_flags.flags =
@@ -603,7 +604,9 @@ wasm_cluster_destroy_spawned_exec_env(WASMExecEnv *exec_env)
         exec_env_tls = exec_env;
     }
 
-    /* Free aux stack space */
+    /* Free aux stack space which was allocated in
+       wasm_cluster_spawn_exec_env */
+    bh_assert(exec_env_tls->is_aux_stack_allocated);
     wasm_cluster_free_aux_stack(exec_env_tls,
                                 (uint64)exec_env->aux_stack_bottom);
 
@@ -655,7 +658,9 @@ thread_manager_start_routine(void *arg)
 #endif
 
     /* Free aux stack space */
-    wasm_cluster_free_aux_stack(exec_env, (uint64)exec_env->aux_stack_bottom);
+    if (exec_env->is_aux_stack_allocated)
+        wasm_cluster_free_aux_stack(exec_env,
+                                    (uint64)exec_env->aux_stack_bottom);
 
     os_mutex_lock(&cluster_list_lock);
 
@@ -723,11 +728,13 @@ wasm_cluster_create_thread(WASMExecEnv *exec_env,
                                          aux_stack_size)) {
             goto fail2;
         }
+        new_exec_env->is_aux_stack_allocated = true;
     }
     else {
         /* Disable aux stack */
         new_exec_env->aux_stack_boundary = 0;
         new_exec_env->aux_stack_bottom = UINTPTR_MAX;
+        new_exec_env->is_aux_stack_allocated = false;
     }
 
     /* Inherit suspend_flags of parent thread */
@@ -1049,7 +1056,9 @@ wasm_cluster_exit_thread(WASMExecEnv *exec_env, void *retval)
 #endif
 
     /* Free aux stack space */
-    wasm_cluster_free_aux_stack(exec_env, (uint64)exec_env->aux_stack_bottom);
+    if (exec_env->is_aux_stack_allocated)
+        wasm_cluster_free_aux_stack(exec_env,
+                                    (uint64)exec_env->aux_stack_bottom);
 
     /* App exit the thread, free the resources before exit native thread */
 

product-mini/platforms/posix/main.c

@@ -675,7 +675,7 @@ main(int argc, char *argv[])
 #endif
 #if WASM_ENABLE_GC != 0
         else if (!strncmp(argv[0], "--gc-heap-size=", 15)) {
-            if (argv[0][21] == '\0')
+            if (argv[0][15] == '\0')
                 return print_help();
             gc_heap_size = atoi(argv[0] + 15);
         }