Add WASI ABI compatibility check for multi-module (#913)

Refer to https://github.com/WebAssembly/WASI/blob/main/design/application-abi.md
to check the WASI ABI compatibility:
- Command (main module) may export _start function with signature "()"
- Reactor (sub module) may export _initialize function with signature "()"
- _start and _initialize can not be exported at the same time
- Reactor cannot export _start function
- Command and Reactor must export memory

And
- Rename module->is_wasi_module to module->import_wasi_api
- Refactor wasm_loader_find_export()
- Remove MULTI_MODULE related codes from mini_loader
- Update multi-module samples
- Fix a "use-after-free" issue. Since we reuse the memory instance of sub module,
   just to protect it from freeing an imported memory instance

Author: lum1n0us

.gitignore

@@ -4,6 +4,10 @@
 /.idea
 **/cmake-build-*/
 **/*build/
+*.obj
+*.a
+*.so
+
 core/deps/**
 core/shared/mem-alloc/tlsf
 core/app-framework/wgl
@@ -12,6 +16,9 @@ wamr-sdk/out/
 wamr-sdk/runtime/build_runtime_sdk/
 test-tools/host-tool/bin/
 product-mini/app-samples/hello-world/test.wasm
+product-mini/platforms/linux-sgx/enclave-sample/App/
+product-mini/platforms/linux-sgx/enclave-sample/Enclave/
+product-mini/platforms/linux-sgx/enclave-sample/iwasm
 
 build_out
 tests/wamr-test-suites/workspace

core/iwasm/aot/aot_loader.c

@@ -1284,7 +1284,7 @@ load_import_funcs(const uint8 **p_buf, const uint8 *buf_end, AOTModule *module,
 #if WASM_ENABLE_LIBC_WASI != 0
         if (!strcmp(import_funcs[i].module_name, "wasi_unstable")
             || !strcmp(import_funcs[i].module_name, "wasi_snapshot_preview1"))
-            module->is_wasi_module = true;
+            module->import_wasi_api = true;
 #endif
     }
 
@@ -2925,7 +2925,7 @@ aot_load_from_comp_data(AOTCompData *comp_data, AOTCompContext *comp_ctx,
     module->comp_data = comp_data;
 
 #if WASM_ENABLE_LIBC_WASI != 0
-    module->is_wasi_module = comp_data->wasm_module->is_wasi_module;
+    module->import_wasi_api = comp_data->wasm_module->import_wasi_api;
 #endif
 
     return module;

core/iwasm/aot/aot_runtime.c

@@ -1059,7 +1059,7 @@ aot_instantiate(AOTModule *module, bool is_sub_inst, uint32 stack_size,
 
 #if WASM_ENABLE_BULK_MEMORY != 0
 #if WASM_ENABLE_LIBC_WASI != 0
-    if (!module->is_wasi_module) {
+    if (!module->import_wasi_api) {
 #endif
         /* Only execute the memory init function for main instance because
             the data segments will be dropped once initialized.

core/iwasm/aot/aot_runtime.h

@@ -256,7 +256,7 @@ typedef struct AOTModule {
 
 #if WASM_ENABLE_LIBC_WASI != 0
     WASIArguments wasi_args;
-    bool is_wasi_module;
+    bool import_wasi_api;
 #endif
 #if WASM_ENABLE_DEBUG_AOT != 0
     void *elf_hdr;

core/iwasm/common/wasm_application.c

@@ -48,10 +48,6 @@ static union {
 /**
  * Implementation of wasm_application_execute_main()
  */
-
-static WASMFunctionInstanceCommon *
-resolve_function(const WASMModuleInstanceCommon *module_inst, const char *name);
-
 static bool
 check_main_func_type(const WASMType *type)
 {
@@ -96,23 +92,29 @@ wasm_application_execute_main(WASMModuleInstanceCommon *module_inst, int32 argc,
     bool ret, is_import_func = true;
 
 #if WASM_ENABLE_LIBC_WASI != 0
-    if (wasm_runtime_is_wasi_mode(module_inst)) {
-        /* In wasi mode, we should call function named "_start"
-           which initializes the wasi envrionment and then calls
-           the actual main function. Directly call main function
-           may cause exception thrown. */
-        if ((func = wasm_runtime_lookup_wasi_start_function(module_inst)))
-            return wasm_runtime_create_exec_env_and_call_wasm(module_inst, func,
-                                                              0, NULL);
-        /* If no start function was found, we execute
-           the main function as normal */
+    /* In wasi mode, we should call function named "_start"
+       which initializes the wasi envrionment and then calls
+       the actual main function. Directly call main function
+       may cause exception thrown. */
+    if ((func = wasm_runtime_lookup_wasi_start_function(module_inst))) {
+        return wasm_runtime_create_exec_env_and_call_wasm(module_inst, func, 0,
+                                                          NULL);
     }
 #endif /* end of WASM_ENABLE_LIBC_WASI */
 
-    if (!(func = resolve_function(module_inst, "main"))
-        && !(func = resolve_function(module_inst, "__main_argc_argv"))
-        && !(func = resolve_function(module_inst, "_main"))) {
-        wasm_runtime_set_exception(module_inst, "lookup main function failed");
+    if (!(func = wasm_runtime_lookup_function(module_inst, "main", NULL))
+        && !(func = wasm_runtime_lookup_function(module_inst,
+                                                 "__main_argc_argv", NULL))
+        && !(func = wasm_runtime_lookup_function(module_inst, "_main", NULL))) {
+#if WASM_ENABLE_LIBC_WASI != 0
+        wasm_runtime_set_exception(
+            module_inst, "lookup the entry point symbol (like _start, main, "
+                         "_main, __main_argc_argv) failed");
+#else
+        wasm_runtime_set_exception(module_inst,
+                                   "lookup the entry point symbol (like main, "
+                                   "_main, __main_argc_argv) failed");
+#endif
         return false;
     }
 
@@ -238,21 +240,23 @@ parse_function_name(char *orig_function_name, char **p_module_name,
  * Implementation of wasm_application_execute_func()
  */
 
-static WASMFunctionInstanceCommon *
-resolve_function(const WASMModuleInstanceCommon *module_inst, const char *name)
+static bool
+resolve_function(WASMModuleInstanceCommon *module_inst, const char *name,
+                 WASMFunctionInstanceCommon **out_func,
+                 WASMModuleInstanceCommon **out_module_inst)
 {
-    uint32 i = 0;
-    WASMFunctionInstanceCommon *ret = NULL;
+    WASMFunctionInstanceCommon *target_func = NULL;
+    WASMModuleInstanceCommon *target_inst = NULL;
+
 #if WASM_ENABLE_MULTI_MODULE != 0
-    WASMModuleInstance *sub_module_inst = NULL;
+    char *function_name = NULL;
     char *orig_name = NULL;
     char *sub_module_name = NULL;
-    char *function_name = NULL;
     uint32 length = (uint32)(strlen(name) + 1);
 
     orig_name = runtime_malloc(sizeof(char) * length, NULL, NULL, 0);
     if (!orig_name) {
-        return NULL;
+        goto LEAVE;
     }
 
     strncpy(orig_name, name, length);
@@ -264,53 +268,33 @@ resolve_function(const WASMModuleInstanceCommon *module_inst, const char *name)
     LOG_DEBUG("%s -> %s and %s", name, sub_module_name, function_name);
 
     if (sub_module_name) {
-        sub_module_inst = get_sub_module_inst((WASMModuleInstance *)module_inst,
-                                              sub_module_name);
-        if (!sub_module_inst) {
+        target_inst = (WASMModuleInstanceCommon *)get_sub_module_inst(
+            (WASMModuleInstance *)module_inst, sub_module_name);
+        if (!target_inst) {
             LOG_DEBUG("can not find a sub module named %s", sub_module_name);
             goto LEAVE;
         }
     }
+    else {
+        target_inst = module_inst;
+    }
 #else
     const char *function_name = name;
+    target_inst = module_inst;
 #endif
 
-#if WASM_ENABLE_INTERP != 0
-    if (module_inst->module_type == Wasm_Module_Bytecode) {
-        WASMModuleInstance *wasm_inst = (WASMModuleInstance *)module_inst;
-
-#if WASM_ENABLE_MULTI_MODULE != 0
-        wasm_inst = sub_module_inst ? sub_module_inst : wasm_inst;
-#endif /* WASM_ENABLE_MULTI_MODULE */
-
-        for (i = 0; i < wasm_inst->export_func_count; i++) {
-            if (!strcmp(wasm_inst->export_functions[i].name, function_name)) {
-                ret = wasm_inst->export_functions[i].function;
-                break;
-            }
-        }
-    }
-#endif /* WASM_ENABLE_INTERP */
-
-#if WASM_ENABLE_AOT != 0
-    if (module_inst->module_type == Wasm_Module_AoT) {
-        AOTModuleInstance *aot_inst = (AOTModuleInstance *)module_inst;
-        AOTFunctionInstance *export_funcs =
-            (AOTFunctionInstance *)aot_inst->export_funcs.ptr;
-        for (i = 0; i < aot_inst->export_func_count; i++) {
-            if (!strcmp(export_funcs[i].func_name, function_name)) {
-                ret = &export_funcs[i];
-                break;
-            }
-        }
-    }
-#endif
+    target_func =
+        wasm_runtime_lookup_function(target_inst, function_name, NULL);
 
 #if WASM_ENABLE_MULTI_MODULE != 0
 LEAVE:
-    wasm_runtime_free(orig_name);
+    if (orig_name)
+        wasm_runtime_free(orig_name);
 #endif
-    return ret;
+
+    *out_func = target_func;
+    *out_module_inst = target_inst;
+    return target_func;
 }
 
 union ieee754_float {
@@ -358,7 +342,8 @@ bool
 wasm_application_execute_func(WASMModuleInstanceCommon *module_inst,
                               const char *name, int32 argc, char *argv[])
 {
-    WASMFunctionInstanceCommon *func;
+    WASMFunctionInstanceCommon *target_func;
+    WASMModuleInstanceCommon *target_inst;
     WASMType *type = NULL;
     uint32 argc1, *argv1 = NULL, cell_num = 0, j, k = 0;
     int32 i, p, module_type;
@@ -368,31 +353,15 @@ wasm_application_execute_func(WASMModuleInstanceCommon *module_inst,
 
     bh_assert(argc >= 0);
     LOG_DEBUG("call a function \"%s\" with %d arguments", name, argc);
-    func = resolve_function(module_inst, name);
 
-    if (!func) {
+    if (!resolve_function(module_inst, name, &target_func, &target_inst)) {
         snprintf(buf, sizeof(buf), "lookup function %s failed", name);
         wasm_runtime_set_exception(module_inst, buf);
         goto fail;
     }
 
-#if WASM_ENABLE_INTERP != 0
-    if (module_inst->module_type == Wasm_Module_Bytecode) {
-        WASMFunctionInstance *wasm_func = (WASMFunctionInstance *)func;
-        if (wasm_func->is_import_func
-#if WASM_ENABLE_MULTI_MODULE != 0
-            && !wasm_func->import_func_inst
-#endif
-        ) {
-            snprintf(buf, sizeof(buf), "lookup function %s failed", name);
-            wasm_runtime_set_exception(module_inst, buf);
-            goto fail;
-        }
-    }
-#endif
-
-    module_type = module_inst->module_type;
-    type = wasm_runtime_get_function_type(func, module_type);
+    module_type = target_inst->module_type;
+    type = wasm_runtime_get_function_type(target_func, module_type);
 
     if (!type) {
         LOG_ERROR("invalid module instance type");
@@ -408,7 +377,7 @@ wasm_application_execute_func(WASMModuleInstanceCommon *module_inst,
     cell_num = (argc1 > type->ret_cell_num) ? argc1 : type->ret_cell_num;
 
     total_size = sizeof(uint32) * (uint64)(cell_num > 2 ? cell_num : 2);
-    if ((!(argv1 = runtime_malloc((uint32)total_size, module_inst, NULL, 0)))) {
+    if ((!(argv1 = runtime_malloc((uint32)total_size, target_inst, NULL, 0)))) {
         goto fail;
     }
 
@@ -538,7 +507,7 @@ wasm_application_execute_func(WASMModuleInstanceCommon *module_inst,
                     void *extern_obj = (void *)(uintptr_t)val;
                     uint32 externref_idx;
 
-                    if (!wasm_externref_obj2ref(module_inst, extern_obj,
+                    if (!wasm_externref_obj2ref(target_inst, extern_obj,
                                                 &externref_idx)) {
                         wasm_runtime_set_exception(
                             module_inst, "map extern object to ref failed");
@@ -563,8 +532,8 @@ wasm_application_execute_func(WASMModuleInstanceCommon *module_inst,
     bh_assert(p == (int32)argc1);
 
     wasm_runtime_set_exception(module_inst, NULL);
-    if (!wasm_runtime_create_exec_env_and_call_wasm(module_inst, func, argc1,
-                                                    argv1)) {
+    if (!wasm_runtime_create_exec_env_and_call_wasm(target_inst, target_func,
+                                                    argc1, argv1)) {
         goto fail;
     }
 

core/iwasm/common/wasm_runtime_common.c

@@ -2294,13 +2294,13 @@ wasm_runtime_is_wasi_mode(WASMModuleInstanceCommon *module_inst)
 {
 #if WASM_ENABLE_INTERP != 0
     if (module_inst->module_type == Wasm_Module_Bytecode
-        && ((WASMModuleInstance *)module_inst)->module->is_wasi_module)
+        && ((WASMModuleInstance *)module_inst)->module->import_wasi_api)
         return true;
 #endif
 #if WASM_ENABLE_AOT != 0
     if (module_inst->module_type == Wasm_Module_AoT
         && ((AOTModule *)((AOTModuleInstance *)module_inst)->aot_module.ptr)
-               ->is_wasi_module)
+               ->import_wasi_api)
         return true;
 #endif
     return false;

core/iwasm/interpreter/wasm.h

@@ -403,7 +403,7 @@ struct WASMModule {
 
 #if WASM_ENABLE_LIBC_WASI != 0
     WASIArguments wasi_args;
-    bool is_wasi_module;
+    bool import_wasi_api;
 #endif
 
 #if WASM_ENABLE_MULTI_MODULE != 0