site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com Hi, I have a socket filter which works most of the time, but I have noticed that sometimes the connections leak, ie, I never receive a sf_detach callback. The circumstance that causes this is when two threads race during the teardown. Specifically, a close() from userspace and a tcp_close() from an aio_worker thread. This is what the aio thread looks like: 0x31db3798 0x21b455 <panic+445> 0x31db37e8 0x21b54b <Assert+65> 0x31db3808 0x383de582 <com.trustdefender.kext.PacketFilter + 0x6582> 0x31db3a78 0x4c44dc <sflt_notify+92> 0x31db3aa8 0x4b1ac1 <soisdisconnected+49> 0x31db3ac8 0x355f63 <tcp_close+669> 0x31db3b08 0x3513dd <tcp_input+13323> 0x31db3cd8 0x3473f6 <ip_proto_dispatch_in+405> 0x31db3d18 0x348a95 <ip_input+5766> 0x31db3e48 0x348bbc <ip_proto_input+47> 0x31db3e68 0x32f121 <proto_input+144> 0x31db3ea8 0x31be3c <lo_input+25> 0x31db3ec8 0x317a3c <dlil_ifproto_input+117> 0x31db3ef8 0x31a1b4 <dlil_input_packet_list+698> 0x31db3f68 0x31a3f5 <dlil_input_thread_func+457> 0x31db3fc8 0x29e6cc <call_continuation+28> and this is the userspace thread (the exact stacktrace will change as the threads are racing, I don't usually manage to catch it but got lucky this time) 0x3794b988 0x226e57 <thread_invoke+1213> 0x3794ba08 0x2270f6 <thread_block_reason+331> 0x3794ba78 0x227184 <thread_block+33> 0x3794ba98 0x29d846 <lck_mtx_lock_wait_x86+330> 0x3794baf8 0x298328 <lck_mtx_lock+504> 0x3794bb08 0x383de363 <com.trustdefender.kext.PacketFilter + 0x6363> 0x3794bd78 0x4c44dc <sflt_notify+92> 0x3794bda8 0x4b1b3f <soisdisconnecting+48> 0x3794bdc8 0x358582 <tcp_disconnect+77> 0x3794bde8 0x358631 <tcp_usr_detach+59> 0x3794be08 0x4ad59e <soclose_locked+742> 0x3794be68 0x4ad646 <soclose+66> 0x3794be88 0x4696fc <fo_close+13> 0x3794bef8 0x46b4ad <close_internal_locked+302> 0x3794bf38 0x46b57e <close_nocancel+141> 0x3794bf78 0x4edaf8 <unix_syscall64+617> 0x3794bfc8 0x29f43d <lo64_unix_scall+77> Usually, the second thread is long gone, and the socket's so_filt has been cleared... but we are still in the sflt_notify() callback, and detach hasn't been called. Also, the socket itself has been put into the socket cache, so its finished its life cycle. This doesn't seem like anything to do with my code simply because my code shouldn't affect when callbacks happen!.... has anyone seen anything like this before? Got any suggestions? Thanks Nick _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... This email sent to site_archiver@lists.apple.com