* John Baldwin <jhb@FreeBSD.org> [020318 10:24] wrote:
>
> On 17-Mar-2002 Robert Watson wrote:
> >
> > On Sun, 17 Mar 2002, Alfred Perlstein wrote:
> >
> >> * Munehiro Matsuda <haro@h4.dion.ne.jp> [020317 06:36] wrote:
> >> >
> >> > PS. I got another message that happend when I ^C'ed a buildworld earlier,
> >> > with same kernel. May be it should go to Alfred Perlstein?
> >> >
> >> > lock order reversal
> >> > 1st 0xc198eec0 pipe mutex @ ../../../kern/sys_pipe.c:779
> >> > 2nd 0xc0367fe0 Giant @ ../../../i386/i386/trap.c:716
> >>
> >> I think there's a place where the pipe can fault on an address while
> >> copying, I'll take a look at this.
> >
> > Are there any assertions that should be in place for copyin/copyout
> > requring fault handling? It sounds like somewhere we need to assert that
> > Giant is held...
>
> More correct is that probably no locks other than Giant should be held for
> copyin/copyout.
s/probably/definetly.
Can you please provide a "blessed" API for raising and lowering a
"can't block" count in the thread? This can be used in copyout,
copyin, and a bunch of vm and buffer ops to make sure we aren't calling
them with mutexes held.
--
-Alfred Perlstein [alfred@freebsd.org]
'Instead of asking why a piece of software is using "1970s technology,"
start asking why software is ignoring 30 years of accumulated wisdom.'
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