Date: Thu, 10 Apr 2014 18:43:03 +0000 (UTC) From: Bruce M Simpson <bms@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r264323 - head/sys/net Message-ID: <201404101843.s3AIh3ZV077523@svn.freebsd.org>
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Author: bms Date: Thu Apr 10 18:43:02 2014 New Revision: 264323 URL: http://svnweb.freebsd.org/changeset/base/264323 Log: In if_freemulti(), relax the paranoid KASSERT() on ifma->ifma_protospec. This KASSERT() existed as a sanity check that upper layers in the network stack (e.g. inet, inet6) had released their reference to the underlying driver's multicast memberships (ifmultiaddr{}). However it assumes the lifecycle of the driver membership corresponds to the lifecycle of the network layer membership. In the submitter's case, ieee80211_ioctl_updatemulti() attempts to reprogram the (parent, physical) ifnet{} memberships in response to a change in membership on the (child, virtual) VAP ifnet, using a batched update mechanism. These updates happen independently from the network layer, causing a "false negative" assertion failure. There are possibly other use cases where this KASSERT() may be triggered by other networking stack activity (e.g. where a nesting relationship exists between multiple ifnet{} instances). This suggests that further review of FreeBSD's approach to nested ifnet relationships is needed. MFC after: 6 weeks Submitted by: adrian@ Modified: head/sys/net/if.c Modified: head/sys/net/if.c ============================================================================== --- head/sys/net/if.c Thu Apr 10 18:34:26 2014 (r264322) +++ head/sys/net/if.c Thu Apr 10 18:43:02 2014 (r264323) @@ -2937,8 +2937,6 @@ if_freemulti(struct ifmultiaddr *ifma) KASSERT(ifma->ifma_refcount == 0, ("if_freemulti: refcount %d", ifma->ifma_refcount)); - KASSERT(ifma->ifma_protospec == NULL, - ("if_freemulti: protospec not NULL")); if (ifma->ifma_lladdr != NULL) free(ifma->ifma_lladdr, M_IFMADDR);
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