Let's say I have a task A that has a specific block of allocated memory. How this task gets into memory and execution is not of consideration; let's just say it is there and somehow it gets processor time.

Let's say this task A has a memory leak that goes beyond the bounds of its allocation, and that this threatens to overwrite all of memory.

Can anyone list EVERY SINGLE POSSIBLE WAY that you can prevent task A from accessing memory outside of its allocation in a X86 32 bit execution environment?

Note that this is a LIST, if you have an idea you would consider to be risky/horrible/just bad, then I still want to hear it.

Also note that task A has full control of the processor at this moment, unless somehow it could be interrupted at the moment of accessing memory outside of its allocation.

I am sorry if this is a stupid question or a repeat, but I have looked a while on this form and I have not really found any question quite as comprehensive as this.

A process should never be able to get full control of the CPU, if it does, then there's no point in protecting the memory pages.

Your process gets virtual memory assigned by your kernel, so the kernel controls what memory can and cannot be written to/read from. If your process allocates memory and there's no assigned virtual memory left for that process, it should request more virtual memory.

The kernel receives this request (probably using a syscall) and can for example check if the process isn't using too much resources yet.

If you don't control what's in the task, then segmentation, page translation, interpretation/emulation of task's code (hardware-assisted virtualization is just a variation on the theme of memory protection with page translation).

If you do, you can just insert checks into the task.

Isn't that basically describing paging? Actually, the entire purpose of this post was to see if there were any alternatives to paging because the pages take up a fair amount of memory on a system with memory constraints, and I don't really need all of the functionalities it promises. I just need to be able to prevent a task from overwriting kernel space.

So, in other words, paging is the only way that you can control an arbitrary process and make sure it obeys the bounds of memory?

Can you elaborate more on each system and roughly give like how much memory it uses and such? I have seen some of what you are saying and have an idea of it, but what I was asking more for was like a bulleted list of each process and perhaps a brief overview on what it entails. I know that it is somewhat vague and perhaps hard/tedious to map out.

Isn't that basically describing paging? Actually, the entire purpose of this post was to see if there were any alternatives to paging because the pages take up a fair amount of memory on a system with memory constraints...