Red zone (computing)
In computing, a red zone is a fixed-size area in a function's stack frame below the current stack pointer that is not preserved by that function. The callee function may use the red zone for storing local variables without the extra overhead of modifying the stack pointer. This region of memory is not to be modified by interrupt/exception/signal handlers. The x86-64 ABI used by System V mandates a 128-byte red zone, which begins directly under the current value of the stack pointer. The OpenRISC toolchain assumes a 128-byte red zone.
