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shadow stack

A second, protected copy of the return addresses: every call writes there too, and every return checks that both copies agree. Not the same as Windows's shadow space.

A hardware shadow stack (Intel CET SHSTK, AMD's equivalent; Windows hardware-enforced stack protection, Linux user shadow stacks) is a separate stack in pages ordinary stores cannot write; call pushes the return address to both stacks and ret raises a control-protection fault (#CP) if they differ.

See also

Control-flow Enforcement Technology control-flow integrity shadow space return address
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