Merge pull request #1057 from UncleGrumpy/esp32_gpio_stop

Fix bug in ESP32 gpio:stop/0 and gpio:close/1

This fixes the bug that causes the VM to crash when the GPIO port driver is
stopped on the ESP32 platform (issue #816). Also adds missing `NULL` check when
the `GPIOData` struct is malloc'd.

These changes are made under both the "Apache 2.0" and the "GNU Lesser General
Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later

Author: bettio

CHANGELOG.md

@@ -19,6 +19,7 @@ easily support integration with Esp32 callbacks
 - ESP32-S3: crash in network driver caused by a smaller stack size for scheduler threads, when
 calling `esp_wifi_init()`. See also issue [#1059](https://github.com/atomvm/AtomVM/issues/1059).
 - Fixed Esp32 network driver on non-SMP builds
+- ESP32: fixed bug in `gpio:stop/0` and `gpio:close/1` that would cause the VM to crash.
 
 ### Changed
 

src/platforms/esp32/components/avm_builtins/gpio_driver.c

@@ -297,6 +297,11 @@ Context *gpio_driver_create_port(GlobalContext *global, term opts)
     Context *ctx = context_new(global);
 
     struct GPIOData *gpio_data = malloc(sizeof(struct GPIOData));
+    if (IS_NULL_PTR(gpio_data)) {
+        ESP_LOGE(TAG, "Not enough free memory to initialize GPIO port driver!");
+        scheduler_terminate(ctx);
+        return NULL;
+    }
     list_init(&gpio_data->gpio_listeners);
 
     ctx->native_handler = consume_gpio_mailbox;
@@ -332,7 +337,7 @@ static term gpiodriver_close(Context *ctx)
             struct GPIOListenerData *gpio_listener = GET_LIST_ENTRY(item, struct GPIOListenerData, gpio_listener_list_head);
             gpio_num = gpio_listener->gpio;
             list_remove(&gpio_listener->gpio_listener_list_head);
-            list_remove(&gpio_listener->listener.listeners_list_head);
+            sys_unregister_listener(ctx->global, &gpio_listener->listener);
             free(gpio_listener);
 
             gpio_set_intr_type(gpio_num, GPIO_INTR_DISABLE);
@@ -344,6 +349,7 @@ static term gpiodriver_close(Context *ctx)
         }
     }
 
+    ctx->platform_data = NULL;
     globalcontext_unregister_process(glb, gpio_atom_index);
     free(gpio_data);