Comment by convolvatron
3 days ago
thats enforced by the VM hardware - we just shuffle the PTEs around to match the appropriate segment view
3 days ago
thats enforced by the VM hardware - we just shuffle the PTEs around to match the appropriate segment view
As long as it's a linear address space, adding/subtracting a large enough value to a pointer (array, stack) could still cross into another "segment".
but those wouldn't be mapped unless you have crossed a call gate that enabled them. the kernel call gate implementation changes the VM map (region visibility) accordingly