On 2006-07-19 13:32, Bruce Evans <[EMAIL PROTECTED]> wrote: >Long ago, On Sat, 1 Jul 2006, Giorgos Keramidas wrote: >>On 2006-06-29 19:22, Yar Tikhiy <[EMAIL PROTECTED]> 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).
Subtle, but important difference. Thanks for taking the time to write down the explanation :-) _______________________________________________ cvs-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/cvs-all To unsubscribe, send any mail to "[EMAIL PROTECTED]"
