How to call functions in ISR using C28x assembly language instructions

I’m developing program using C28x assembly language instructions on TMS320F28035. As I programmed flash and run it, there is a fault when calling functions in ISR, as if program running out. I’m sure there is no problem about interrupt context saving and restoring as follows:

ISR_Service:

; Interrupt context save:

PUSH AR1H:AR0H                                                                

PUSH XAR2                              

PUSH XAR3                                

PUSH XAR4                                

PUSH XAR5                                

PUSH XAR6

PUSH XAR7

PUSH XT

;Interrupt code:

;call functions

;Interrupt context restore:

POP XT

POP XAR7

POP XAR6

POP XAR5

POP XAR4

POP XAR3

POP XAR2

POP AR1H:AR0H

IRET

The CCS version is 3.3.83.20. Please tell me the reason for this problem and how to deal with it. Thank you very much.