Messages in this thread | | | From | Jesse Pollard <> | Subject | Re: top stack (l)users for 2.5.69 | Date | Wed, 7 May 2003 17:01:11 -0500 |
| |
On Wednesday 07 May 2003 16:54, Timothy Miller wrote: > Jesse Pollard wrote: > > On Wednesday 07 May 2003 12:13, Jonathan Lundell wrote: > > [snip] > > > >>One thing that would help (aside from separate interrupt stacks) > >>would be a guard page below the stack. That wouldn't require any > >>physical memory to be reserved, and would provide positive indication > >>of stack overflow without significant runtime overhead. > > > > It does take up a page table entry, which may also be in short supply > > Now, I'm sure this has GOT to be a terribly ignorant question, but I'll > try anyhow: > > What happens if you simply neglect to provide a mapping for that page? > I'm sure that will cause some sort of page fault. Why would you have to > do something different?
I believe it shifts the entire virtual range up(/down depending on your point of view). Each page in the virtual address range (whether it physically exists or not) has a descriptor. To reserve one requires that the descriptor be set to "does not exist, no read, no write". Then any access to that page can/will generate a trap. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |