Wifi crash linked to FreeRTOS Port.c

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1

I converted an ESP32 sample C program to C++ which basically opens the Wifi in Station mode. The program works right up to the point where I get an IP address back from the router – then crashes. I decoded my backtrace which points to freertos/port.c

Will someone please tell me what port.c is doing for Wifi? There is hardly a line of comment in that source file that says anything about its function. There is a lot of disclaimer jazz in there – nothing that gives me the bigger picture.

Here is my backtrace:

Wifi::event_handler(void*, char const*, int, void*) main/Wifi.cpp:1271 (discriminator 8)

Wifi::eventMarshaller(void*, char const*, int, void*) main/Wifi.cpp:1190

handler_execute at C:/SysGCC/esp32/esp-idf/v4.0/components/esp_event/esp_event.c:145

esp_event_loop_run at C:/SysGCC/esp32/esp-idf/v4.0/components/esp_event/esp_event.c:553 (discriminator 3)

esp_event_loop_run_task at C:/SysGCC/esp32/esp-idf/v4.0/components/esp_event/esp_event.c:115

vPortTaskWrapper at C:/SysGCC/esp32/esp-idf/v4.0/components/freertos/port.c:143

Final reference here – line 143 points to this small function:

#if CONFIG_FREERTOS_TASK_FUNCTION_WRAPPER
// Wrapper to allow task functions to return (increases stack overhead by 16 bytes)
static void vPortTaskWrapper(TaskFunction_t pxCode, void *pvParameters)
{
pxCode(pvParameters);
//FreeRTOS tasks should not return. Log the task name and abort.
char * pcTaskName = pcTaskGetTaskName(NULL);
ESP_LOGE(“FreeRTOS”, “FreeRTOS Task “%s” should not return, Aborting now!”, pcTaskName);
abort();
}
#endif

2

@KeithInAsia I tried building station example in ESP-IDF with C++ and did not find any issues.

Issue you are facing generally occurs if you are returning from a task(a task should never return). Can you please confirm the same?

3

In my run task I do not return…

This crash traces back to my event handler. Specifically back to the IP_EVENT, IP_EVENT_STA_GOT_IP handler.

case IP_EVENT_STA_GOT_IP : { // ESP32 station got IP from connected AP
ESP_LOGI(TAG, " IP_EVENT_STA_GOT_IP");
ip_event_got_ip_t* event = (ip_event_got_ip_t*) event_data;
ESP_LOGI(TAG, “got ip:%s”, ip4addr_ntoa(&event->ip_info.ip)) ;
s_retry_num = 0 ;
xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
}

Inside the function – the 5 lines inside – if I comment a few of them out – the crash stops.

The Log statement is always ok.

Most of the time does not crash with only Lines 2, 3 lines enabled.

Always crashes with line 4 enabled.

Always crashes with xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);

I don’t see how any of this ties back to the run task in that object…

If you built the station example in ESP-IDF with C++ then you have a lot of changes to do to make it compile. Did you change the main from .c to.cpp?

4

hi , @KeithInAsia did you find an solution regarding to this issue , because even for me it is crashing .
Guru Meditation Error: Core 0 panic’ed (LoadProhibited). Exception was unhandled.

Core 0 register dump:
PC : 0x401b1fb0 PS : 0x00060230 A0 : 0x801b2050 A1 : 0x3ffd0530
0x401b1fb0: esp_event_loop_run at C:/v4.4.3/esp-idf/components/esp_event/esp_event.c:586 (discriminator 3)

A2 : 0x3ffcf84c A3 : 0xffffffff A4 : 0xfb0000e0 A5 : 0xfb0000e0
A6 : 0x00000000 A7 : 0x3f4f64f0 A8 : 0x3ffdd2d4 A9 : 0x3ffd0500
A10 : 0x3ffcf84c A11 : 0x00000000 A12 : 0x00000000 A13 : 0x3f4f64f0
A14 : 0x00000005 A15 : 0x00000000 SAR : 0x0000001a EXCCAUSE: 0x0000001c
EXCVADDR: 0xfb0000ec LBEG : 0x4000c2e0 LEND : 0x4000c2f6 LCOUNT : 0xffffffff

Backtrace: 0x401b1fad:0x3ffd0530 0x401b204d:0x3ffd0570 0x4008e571:0x3ffd0590
0x401b1fad: esp_event_loop_run at C:/v4.4.3/esp-idf/components/esp_event/esp_event.c:594 (discriminator 1)

0x401b204d: esp_event_loop_run_task at C:/v4.4.3/esp-idf/components/esp_event/esp_event.c:115 (discriminator 15)

0x4008e571: vPortTaskWrapper at C:/v4.4.3/esp-idf/components/freertos/port/xtensa/port.c:131

ELF file SHA256: 5351570e1e3da409

Rebooting…
ets Jul 29 2019 12:21:46

This is happening after successful provisioning and then crashing while switching to station mode .

code lines i suspect :

else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP)
{
ip_event_got_ip_t* event = (ip_event_got_ip_t*) event_data;
ESP_LOGI(TAG, “got ip:” IPSTR “\n”, IP2STR(&event->ip_info.ip));
xEventGroupSetBits(s_wifi_event_group, WIFIEVT_CONNECT_BIT);
xEventGroupClearBits(s_wifi_event_group, WIFIEVT_DISCONNECT_BIT | WIFIEVT_APPDISCONNECT_BIT);
}

5

Hello @Amanem can you check using breakpoints in your code to see exactly where is the code crashing? That might help us in zeroing in on the issue.

Thanks

6

unfortunately all my pins are begin used and i don’t have debugger too , so i used logging statements to do this

8

Have you checked for stack overflows?

9

Hey , i found some wifi function was called multiple times , due to which crashing was happening .
Thanks .

10

Thank you for reporting back!