The push+reti option (as Felix suggested, or with some variants) is widely used. You can put a label "labelname" marking the code where you want to jump and use mov dptr,#labelname. I think that the "jump" should go to an entry point where the program makes a SW-reset including SP initialization. This "tricks" must be well documented, to ease the SW maintanance.

Using an interrupt as the enter point for a watch-dog recovery system is not advisable, except for non maskable interrupts (NMI). The interrupts in the standard 8052 are all maskable, so if the interrupt you use is disabled by an out-of-control uC, the ISR never runs.

Alfredo.