Crashes using cJSON and fprinting strings using CC3200 and TI-RTOS

I'm working on a little project on the CC3200 launchxl that essentially is an MQTT client (paho based) for remote sensing and control. As the message payload will be JSON encoded, I need some JSON parsing. For this I'm using cJSON. For setting up the app I've used the TCP connection demo that came with the CC3200 SDK.

I have a problem when I call cJSON. It's called within the same rtos task as my mqtt client.

I get the following response in the console, when the cJSON_Parse() function is hit:

	ti.sysbios.family.arm.m3.Hwi: line 1036: E_hardFault: FORCED
	ti.sysbios.family.arm.m3.Hwi: line 1113: E_busFault: IBUSERR: Instruction Access Violation, address: e000ed38
	Exception occurred in background thread at PC = 0x00343130.
	Core 0: Exception occurred in ThreadType_Task.
	Task name: {unknown-instance-name}, handle: 0x20019a40.
	Task stack base: 0x20019a90.
	Task stack size: 0x1000.
	R0 = 0x00000028  R8  = 0x2001a984
	R1 = 0x00343131  R9  = 0x2001a974
	R2 = 0x00000000  R10 = 0xffffffff
	R3 = 0x20021473  R11 = 0xffffffff
	R4 = 0x200296ff  R12 = 0x2002a364
	R5 = 0x2002945c  SP(R13) = 0x2001a870
	R6 = 0x200296ff  LR(R14) = 0x200059f7
	R7 = 0x00000000  PC(R15) = 0x00343130
	PSR = 0x21000000
	ICSR = 0x0400f803
	MMFSR = 0x00
	BFSR = 0x01
	UFSR = 0x0000
	HFSR = 0x40000000
	DFSR = 0x0000000b
	MMAR = 0xe000ed34
	BFAR = 0xe000ed38
	AFSR = 0x00000000
	Terminating execution...

Below, the JSON parser routine concerned. For testing the JSONString is fixed. It crashed immedeately after the cJSON_Parse() call, which probably sets up the JSON structure in memory.

int JSONPayloadHandler(){
		cJSON *json; int i, device_count;
	
		const char JSONString[] = "{\"devices\":[{\"id\":42,\"kind\":\"tv_set\",\"state\":\"on\"}]}";
	
		json = cJSON_Parse(JSONString);
		if (!json) {
			DBG_PRINT("JSON parse error before: [%s]\n", cJSON_GetErrorPtr());
			return -1;
		} else {
	
			DBG_PRINT("JSON parse success\n\r");
	
			cJSON * devices = cJSON_GetObjectItem(json, "devices");
	
			device_count = cJSON_GetArraySize(devices);
	
			for (i = 0; i < device_count; i++) {
				cJSON * item = cJSON_GetArrayItem(devices, i);
	
				if (!strcmp(cJSON_GetObjectItem(item, "kind")->valuestring, "tv_set")) {
					printf("Found da boiler on id: %i\n", cJSON_GetObjectItem(item, "id")->valueint);
	
					(!strcmp(cJSON_GetObjectItem(item, "state")->valuestring, "on")) ?
							DBG_PRINT("ON!") : DBG_PRINT("off");
				}
	
			}
			cJSON_Delete(json);
		}
		return 0;
	}

If I run above function outside any TI-RTOS task context (i.e. before osi_start() is called) there's no problem, even if i run it from within another task (AppConnect) it runs fine.

Furthermore, I noticed that when I print "largish" strings (e.g >100 bytes) with the Report() UART printer, I sometimes get the buserrors and the like. Using floats in a (sn)printf function can lead to similar crashes as well. All in all the application seems really really fragile.

I'm completely in the dark why this is happening. My guess is that it has to do something with memory allocation in combination with RTOS or some RTOS setting. I hope someone with more RTOS knowledge has any idea what causes this or how to further investigate.

Happy to hear from you.

Thanks in advance!