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From: Bruce Wilson <bruce.wilson2@xxxxxxxxxxx> > On earlier releases it found the EXT entry point ... currently it will execute > the first entry point regardless of type .. knowing if this is INT and that > there is no connection back to the invocation stack, and by setting return > instruction pointer with care one perhaps can violate the architecture and > open security vulnerabilities? > Branching to an instruction pointer passed as a parameter is done by a BCCTR RISC-instruction. If you disassemble the generated RISC code (e.g. with SST) and find the BCCTR instruction, you will find just before it a TD instruction. This instruction is the one that checks for valid branch point. Replace the TD instruction by a NOP (hex 60000000) and you can do your unnatural act. But beware, you have to do things exactly right, or your machine will fall over.
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