Miklos Szeredi wrote:

quoted text
> On Thu, 28 Aug 2008, H. Peter Anvin wrote:

>> This is *hard* to get right, and we screw this up in the kernel with

>> painful regularity.  The throught of having user-space processes, which

>> don't have access to the kernel locking primitives and functions like

>> copy_from_user() dealing with this stuff scares me crazy.

>

> What issues exactly are you thinking of?

Memory changing underneath you.  It can be dealt with by very careful

sequencing only.
>> That is why I'm suggesting using an in-kernel linearizer.

quoted text
>

> Lots of complexity, ugh...  Even Tejun's current scheme is better IMO.

And then you get *no* privilege separation, for one thing, so why even

bother doing it in userspace?
	-hpa

--

unsubscribe notice
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/