On Thu, Nov 23, 2000 at 10:04:18PM +0100, Bjorn Wesen wrote:
> On Thu, 23 Nov 2000, Andreas Bombe wrote:
> > > I may be wrong on this, but I thought that copy_{to,from}_user are
> > > only necessary if the address range you are accessing might cause a
> > > fault which Linux cannot handle (ie. one
Hi!
> otherwise valid) I think the access macros are unnecessary. I would be
> *very* glad if someone could confirm this, or shoot me down. :)
>
> For instance, a kernel module I am writing allocates some memory in
> the current process's address space as follows:
>
> down(&mm->mmap_sem);
>
On Thu, 23 Nov 2000, Andreas Bombe wrote:
> > I may be wrong on this, but I thought that copy_{to,from}_user are
> > only necessary if the address range you are accessing might cause a
> > fault which Linux cannot handle (ie. one which would cause the
> > application to segfault if it accessed tha
On Wed, Nov 22, 2000 at 09:39:51PM +, Keir Fraser wrote:
> > The reason that everyone else uses copy_{to,from}_user is that there
> > is no way to guarantee that the userspace pointer is valid. That
> > memory may have been swapped out. The copy macros are prepared to
> > fault the memory in.
> The reason that everyone else uses copy_{to,from}_user is that there
> is no way to guarantee that the userspace pointer is valid. That
> memory may have been swapped out. The copy macros are prepared to
> fault the memory in. The rest of the kernel is not.
>
> Jeff
I may be wrong on this, but
[EMAIL PROTECTED] said:
> Does anybody know a function or method in order to translate an user
> space pointer into a valid pointer in kernel mode?
> I'd like to avoid copying data (such as the 'copy_to_user' and
> 'copy_from_user' functions do) because it slows down my system.
The reason
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