Messages in this thread | | | Date | Fri, 24 Feb 2012 10:19:36 -0500 | Subject | Re: Can we move device drivers into user-space? | From | Jidong Xiao <> |
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On Wed, Feb 22, 2012 at 11:56 PM, Jidong Xiao <jidong.xiao@gmail.com> wrote: > Hi, > > I am just curious. Since the concept user-space device drivers has > been proposed for several years, and some related projects and > research papers have demonstrated the feasibility of of moving device > drivers into use space. In particular, this paper: > > Tolerating Malicious Device Drivers in Linux. > http://pdos.csail.mit.edu/papers/sud:usenix10.pdf > > In this paper, existing device driver code need not to be changed, > which should help the idea to be applied in practice. > > The advantage and disadvantage of move device drivers into use space > of both obvious: > > Advantage: Since most of kernel bugs are caused by device drivers > issues, moving device drivers into user space can reduce the impact of > device driver bugs. From security perspective, the system can be more > secure and robust if most device drivers are working in user space. > Disadvantage: At least, existing techniques as well as the above paper > showed a relatively high overhead. > > So is it mainly because the high overhead that prevents the user-space > device drivers ideas being accepted in Linux? >
Actually, my major concern is, since UIO has been accepted, then why don't we move all the rest device drivers into user space as well. As I understand, currently, some of device drivers are running on user space, while the other (or say the majority of) device drivers are running on kernel space, so why don't we maintain a consistent device drivers infrastructure, say, either all in user space, or all in kernel space. (Sure some critical device drivers still need to be kept in kernel space.)
-Jidong
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