lkml.org 
[lkml]   [2002]   [May]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: AUDIT: copy_from_user is a deathtrap.
Alan Cox wrote:
>
> > In such case, linus, here is your "reasonable" example. For PPro, it
> > is faster to copy out-of-order, and if we wanted to use that for
> > copy_to_user, you'd have your example.
>
> I think there is a misunderstanding here.
>
> Nothing in the standards says that
>
> write(pipe_fd, halfmappedbuffer, 2*PAGE_SIZE)
>
> must return PAGE_SIZE on an error. What it seems to say is that it if an error
> is reported then no data got written down the actual pipe itself. Putting
> 4K into the pipe then reporting Esomething is not allowed. Copying 4K into
> a buffer faulting and erroring with Efoo then throwing away the buffer is
> allowed

write might be the easy case. But what about read?
Is a failing read allowed to change the userspace
memory?

--
Kasper Dupont -- der bruger for meget tid på usenet.
For sending spam use mailto:razor-report@daimi.au.dk
-
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/

\
 
 \ /
  Last update: 2005-03-22 13:26    [W:1.606 / U:1.268 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site