Segmentation fault protection: Difference between revisions
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Puppydrum64 (talk | contribs) (Created page with "{{draft task}} A segmentation fault or '''segfault''' is an error that your computer will raise if a program attempts to access memory that it's not...") |
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Showcase what built-in protections your language has for segmentation faults, if any. If your language doesn't have any, show what happens when your program commits a segmentation fault. (Be safe and don't destroy your computer!)
{{header|6502 Assembly}}
The 6502 doesn't have any handlers for access violation; the entire address space of the CPU is fair game. As you can imagine this isn't good for computer security.
However, the stack being fixed at $0100-$01FF means that the stack will never overwrite the heap, yet it can get to the point where new values pushed onto the stack overwrite the old, which can cause a CPU crash if you try to unwind the stack back to the beginning.
The 6502 uses memory-mapping to interact with external hardware, and reading/writing a memory location you normally shouldn't because your array indexed out of bounds can cause issues with external hardware, and even on some systems can result in a [[wp:Killer_poke|killer poke]] which can damage certain machines such as the Commodore PET. Memory-mapped ports don't work like normal memory; unlike normal memory, even ''reading'' a memory-mapped port can affect its contents, or affect the contents of other ports that are related to that hardware. (This isn't a property of the 6502 itself, but of the hardware connected to it.)
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