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author | bz <bz@FreeBSD.org> | 2010-04-11 11:51:44 +0000 |
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committer | bz <bz@FreeBSD.org> | 2010-04-11 11:51:44 +0000 |
commit | d5b3b3f9d9f415d433fc76253779bd585b99c59f (patch) | |
tree | 733dc8c0a6a210cc18db521af3307fceaaca1da9 /sys/net | |
parent | 674a87c918aac879260de667e43372e3fe9b355b (diff) | |
download | FreeBSD-src-d5b3b3f9d9f415d433fc76253779bd585b99c59f.zip FreeBSD-src-d5b3b3f9d9f415d433fc76253779bd585b99c59f.tar.gz |
In if_detach_internal() we cannot hold the af_data lock over the
dom_ifdetach() calls as they might sleep for callout_drain().
Do as we do in if_attachdomain1() [r121470] and handle
if_afdata_initialized earlier and call dom_ifdetach() unlocked.
Discussed with: rwatson
MFC after: 10 days
Diffstat (limited to 'sys/net')
-rw-r--r-- | sys/net/if.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/sys/net/if.c b/sys/net/if.c index 1cdc20b..e4a2005 100644 --- a/sys/net/if.c +++ b/sys/net/if.c @@ -897,14 +897,20 @@ if_detach_internal(struct ifnet *ifp, int vmove) devctl_notify("IFNET", ifp->if_xname, "DETACH", NULL); if_delgroups(ifp); + /* + * We cannot hold the lock over dom_ifdetach calls as they might + * sleep, for example trying to drain a callout, thus open up the + * theoretical race with re-attaching. + */ IF_AFDATA_LOCK(ifp); - for (dp = domains; ifp->if_afdata_initialized > 0 && dp; dp = dp->dom_next) { + i = ifp->if_afdata_initialized; + ifp->if_afdata_initialized = 0; + IF_AFDATA_UNLOCK(ifp); + for (dp = domains; i > 0 && dp; dp = dp->dom_next) { if (dp->dom_ifdetach && ifp->if_afdata[dp->dom_family]) (*dp->dom_ifdetach)(ifp, ifp->if_afdata[dp->dom_family]); } - ifp->if_afdata_initialized = 0; - IF_AFDATA_UNLOCK(ifp); } #ifdef VIMAGE |