cvs commit: src/sys/netipsec ipsec_mbuf.c

[Andre Oppermann]

Sam Leffler wrote:
> 
> Andre Oppermann wrote:
> > Sam Leffler wrote:
> >
> >>Andre Oppermann wrote:
> >>
> >>>andre       2005-09-26 20:35:45 UTC
> >>>
> >>>  FreeBSD src repository
> >>>
> >>>  Modified files:
> >>>    sys/netipsec         ipsec_mbuf.c
> >>>  Log:
> >>>  Replace custom mbuf writeability test with generic M_WRITABLE() test
> >>>  covering all edge cases too.
> >>
> >>I vaguely recall that M_WRITEABLE did exist when I wrote that code but
> >>it did not do the right thing.  I'm not sure why you needed to make this
> >>change but beware of unexpected side effects.
> >
> >
> > The test in question tries to determine whether to copy the mbuf to make
> > to safe for modification.  The old did not respect the M_RDONLY for example.
> > M_WRITABLE() correctly tests for all cases.
> >
> 
> And as I said; I did it for a reason that I cannot recall now.  I'm
> certain that it was pre-mbufs-over-uma so maybe this is now safe but
> such are the ways that subtle bugs are introduced into code...

Indeed.

-- 
Andre