Date: Mon, 26 Sep 2005 13:57:53 -0700 From: Sam Leffler <sam@errno.com> To: Andre Oppermann <andre@FreeBSD.org> Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/netipsec ipsec_mbuf.c Message-ID: <433860D1.5000200@errno.com> In-Reply-To: <43385F03.B0BDA733@freebsd.org> References: <200509262035.j8QKZj04022444@repoman.freebsd.org> <43385C89.60009@errno.com> <43385F03.B0BDA733@freebsd.org>
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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... Sam
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