3 ms·

in systems with unprotected memory, you would actually access the address; even though you accessed it, it is a violation, the result is undefined. When there i

in systems with unprotected memory, you would actually access the address; even though you accessed it, it is a violation, the result is undefined. When there is protected memory, what catches the violation is outside of your process space. It is a violation; possibly I should not have said OS, it's a hardware violation. I'm not the only one who says this, look at the name, -V edit: actually, though hardware support is required for certain OS features, it's the OS that sets up the segmentation and the fault handlers so ... it is ultimately an OS contract.

klodolph 6y ago
As the article notes, the -V suffix is a historical curiosity. Since no contract is being violated here, the term “violation” does not make sense. This is nothing more than a fault condition, like trying to open a file that does not exist or trying to go to a webpage that does not exist. The contract with the OS is that if you access unmapped memory, your program is sent SIGSEGV. Just like the contract with open() is that it returns -1 if the file is not found.