[Bug 160284] bad mmap causes cores in KPCMemoryDevice

[Matthew Woehlke]

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http://bugs.kde.org/show_bug.cgi?id=160284         




------- Additional Comments From mw_triad users sourceforge net  2008-05-30 18:22 -------
> The man pages I have for mmap(2) indicate that Linux is more than happy to throw SIGBUS if the underlying file has been deleted/truncated.

Cool, even more likely then someone found the problem I was getting bit by. But there was plenty of stuff before that was talking about "alignment" :-).

A race seems possible, but what I seem to recall from walking the code is that the point of failure is just a few lines after the actual call to mmap, so I'm a bit more dubious that it's a reentrancy thing. But then, I haven't looked at the code in some time...

> I noticed that mmap support can be disabled.  Is this an enormous slowdown if disabled or can we disable it by default until this is more ironclad?

I'd be in favor of that, especially if you do it the same way I did, if only because it'll merge with my local change such that when it's decided to re-enable it, that will magically happen for me :-).