> I was under the impression that this was a no-no & one should use
> copyin/copout & friends to access memory on users's stacks. Although
> this appears to work on the i386, if I try this on the alpha I take a
> fatal trap when accessing *set.
>
> So -- how does this work on the i386? Is the user's stack always
> mappeped into the kernel's address space? Should it also work on the
> alpha?
>
On i386, under the current implementation, the kernel can directly access
curproc's address space (not just the stack, stack is used because we're
sure the spare space won't/shouldn't be used by the user application).
I don't know if the same is true for alpha, but this should definitely
be considered an implementation dependent feature. I wish there were some
other ways to bypass copyin/out in ioctls.
-lq
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-hackers" in the body of the message
