Nested Bus as S-Function input

Hi,

I'm trying to compile some legacy code as a s-function, and I'd like to pass a struct as input. I created a bus that replicates that struct and imports its definition from the legacy header file. One of the fields of that struct is a pointer to an array of structs.

I configured the s-function to accept a bus as input:

 %
if (!ssSetNumInputPorts(S, 1)) return; 
ssSetInputPortWidth(S, 0, INPUT_0_WIDTH); 
ssSetInputPortComplexSignal(S, 0, COMPLEX_NO); 
ssSetInputPortDirectFeedThrough(S, 0, 1); 
ssSetInputPortRequiredContiguous(S, 0, 1); 
ssSetBusInputAsStruct(S, 0, IN_0_BUS_BASED); 
ssSetInputPortBusMode(S, 0, SL_BUS_MODE);

Then I'm allocating memory for the struct:

 %
static void mdlStart(SimStruct *S) 
{ 
int_T *busInfo = (int_T *)malloc(sizeof(PARAM_EST_SETUP_TYPE) + 3*sizeof(DIGITAL_FILTER_BIQUAD_COEFF_TYPE)); 
ssSetUserData(S, busInfo); 
}

Note that I added 3*sizeof(DIGITAL_FILTER_BIQUAD_COEFF_TYPE) to the malloc call in order to allocate memory for the struct array that is referenced inside PARAM_EST_SETUP_TYPE.

Finally, when I try to execute that S-Function Simulink crashes due to memory access violation. What am I doing wrong?

I'm sending my sfunction.c code attached.

Thanks,

Guilherme