lkml.org 
[lkml]   [2001]   [Oct]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Security question: "Text file busy" overwriting executables but not shared libraries?
Linus Torvalds wrote:
> On Sat, 13 Oct 2001, Jamie Lokier wrote:
> > I can think of an efficiency-related use for MAP_COPY, and it has
> > nothing to do with shared libraries:
> >
> > - An editor using mmap() to read a file.
>
> No, you're thinking the wrong way.
...
> People who think MAP_COPY is a good idea are people who cannot think about
> the implications of it, and cannot think about the alternatives.
:-)
> In particular, you claim that you could use "mmap()" for "read()", and
> speed up the application that way. Ok, fair enough.
>
> Now, somebody who _isn't_ stupid (and that, of course, is me), immediately
> goes "well, _duh_, why don't you speed up read() instead?".

Thanks Linus. You are right, speeding up read() is the right thing to do.

In fact it was proposed here on this list years ago, and I think you
argued against it (TLB flush costs). The costs and kernel
infrastructure have changed and maybe the idea could be revisited now.

Sometimes one has to be an idiot and explore an application of MAP_COPY
to get someone looking at sensible old ideas again :-)

have a nice day,
-- Jamie
-
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 13:08    [W:0.107 / U:3.368 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site