Date: Wed, 19 Jul 2006 11:38:40 +0400 From: Yar Tikhiy <yar@comp.chem.msu.su> To: Bruce Evans <bde@zeta.org.au> Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, Giorgos Keramidas <keramida@FreeBSD.org>, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/net if.c if_atmsubr.c if_stf.c if_tun.c src/sys/netinet if_ether.c ip_divert.c ip_fw2.c src/sys/netinet6 in6.c in6_var.h src/sys/nfsclient bootp_subr.c nfs_diskless.c Message-ID: <20060719073840.GC69362@comp.chem.msu.su> In-Reply-To: <20060719131841.U41630@delplex.bde.org> References: <200606291922.k5TJM5ev007314@repoman.freebsd.org> <20060701003326.GA41947@gothmog.pc> <20060719131841.U41630@delplex.bde.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Jul 19, 2006 at 01:32:26PM +1000, Bruce Evans wrote: > Long ago, On Sat, 1 Jul 2006, Giorgos Keramidas wrote: > > >On 2006-06-29 19:22, Yar Tikhiy <yar@freebsd.org> wrote: > >>yar 2006-06-29 19:22:05 UTC > >> > >> FreeBSD src repository > >> > >> Modified files: > >> sys/net if.c if_atmsubr.c if_stf.c if_tun.c > >> sys/netinet if_ether.c ip_divert.c ip_fw2.c > >> sys/netinet6 in6.c in6_var.h > >> sys/nfsclient bootp_subr.c nfs_diskless.c > >> Log: > >> There is a consensus that ifaddr.ifa_addr should never be NULL, > >> except in places dealing with ifaddr creation or destruction; and > >> in such special places incomplete ifaddrs should never be linked > >> to system-wide data structures. Therefore we can eliminate all the > >> superfluous checks for "ifa->ifa_addr != NULL" and get ready > >> to the system crashing honestly instead of masking possible bugs. > > > >This is probably silly, but it was the first thing I thought about when > >I saw the NULL checks removed. > > > >Since we assume that ifa->ifa_addr != NULL, does it make sense to add > >KASSERT() calls in the places where we do so? > > No, that would be worse than leaving the checks unchanged. Asserting > that pointers aren't null just re-bloats the code (at least at the > source level) and breaks normal handling of dereferencing of null > pointers. With normal handling, you get a trap that can be restarted > using a debugger, but with assertions (if assertions are enabled) you > get a panic that can't be restarted (modulo the RESTARTABLE_PANICS > option which causes other problems). Seconded. I believe that KASSERT() shouldn't be routinely used for NULL checks, it's for more complex consistency tests. -- Yar
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20060719073840.GC69362>