hard fault when taking semaphore in FreeRTOS

Question

Hi, 
 I'm trying to use a GPIO interrupt and a semaphore to trigger a free rtos taskm but whenever I run xSemaphoreTake i get a hard fault error. 
 // Semaphore to signal interrupt pin change
SemaphoreHandle_t m_ppg_semaphore;

static void ppg_test_task(void *pvParameter){
 UNUSED_PARAMETER(pvParameter);

 m_ppg_semaphore = xSemaphoreCreateBinary();
 ASSERT(NULL != m_ppg_semaphore);

 gpio_init();

 //volatile enum ppgInterupt ppgState = notReady;
 // Read the interrupt registers to clear them
 //uint8_t buffer;
 //bool stay = false;
 while (true) {
 bool temp = xSemaphoreTake(m_ppg_semaphore, portMAX_DELAY);

 // Turn an LED on to signify the start of data reading
 bsp_board_led_invert(BSP_BOARD_LED_3);
 }
}

void in_pin_handler(nrf_drv_gpiote_pin_t pin, nrf_gpiote_polarity_t action) {
 BaseType_t yield_req = pdFALSE;

 /* The returned value may be safely ignored, if error is returned it only means that
 * the semaphore is already given (raised). */
 UNUSED_VARIABLE(xSemaphoreGiveFromISR(m_ppg_semaphore, &yield_req));
 portYIELD_FROM_ISR(yield_req);
}
/**
 * @brief Function for configuring: PIN_IN pin for input, PIN_OUT pin for output,
 * and configures GPIOTE to give an interrupt on pin change.
 */
static void gpio_init(void) {
 ret_code_t err_code;

 err_code = nrf_drv_gpiote_init();
 APP_ERROR_CHECK(err_code);

 nrf_drv_gpiote_in_config_t in_config = GPIOTE_CONFIG_IN_SENSE_HITOLO(true);
 in_config.pull = NRF_GPIO_PIN_PULLUP;

 err_code = nrf_drv_gpiote_in_init(INT_IN, &in_config, in_pin_handler);
 APP_ERROR_CHECK(err_code);

 nrf_drv_gpiote_in_event_enable(INT_IN, true);

 NRF_LOG_INFO("GPIO Configured");
}