On Fri, 21 Jan 2005 12:59:59 +0100, Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote: > On Thu, 2005-01-20 at 12:54 -0600, Timur Tabi wrote: > > I recently discovered in a driver I'm working on that there are several > > places where a user-space virtual address is being dereferenced > > successfully. I was under the impression that that should not work - > > user pointers should not be usuable in kernel space. > > it may work. you may be lucky. The page also may be swapped out and you > crash and burn > as for fc2/3; those kernels have a separate address space for user and > kernel, and as a result such rogue accesses will almost always crash, > not just sometimes. You know, I had wondered what use this patchset had other than for folks with 32bit systems straining under userspace limits - this is actually a pretty cool driver diagnostic tool in and of itself :-) Jon. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
