Bug 211531
| Summary: | Hitting non sleepable lock panic for lock "unp_link_rwlock" | ||
|---|---|---|---|
| Product: | Base System | Reporter: | rdarbha <raviprakash.darbha> |
| Component: | kern | Assignee: | Mark Johnston <markj> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | CC: | cem, markj |
| Priority: | --- | Keywords: | patch |
| Version: | 10.3-STABLE | ||
| Hardware: | Any | ||
| OS: | Any | ||
Can someone please review this ? https://reviews.freebsd.org/D7398 Fixed with r303855. A commit references this bug: Author: pho Date: Tue Aug 9 11:37:08 UTC 2016 New revision: 303871 URL: https://svnweb.freebsd.org/changeset/base/303871 Log: Added a regression test. PR: 211531 Submitted by: markj Sponsored by: EMC / Isilon Storage Division Changes: user/pho/stress2/misc/unix_socket_detach.sh A commit references this bug: Author: markj Date: Wed Aug 31 21:35:12 UTC 2016 New revision: 305159 URL: https://svnweb.freebsd.org/changeset/base/305159 Log: MFC r303855: Handle races with listening socket close when connecting a unix socket. PR: 211531 Changes: _U stable/11/ stable/11/sys/kern/uipc_usrreq.c stable/11/sys/sys/unpcb.h A commit references this bug: Author: markj Date: Wed Aug 31 21:35:51 UTC 2016 New revision: 305161 URL: https://svnweb.freebsd.org/changeset/base/305161 Log: MFC 303855: Handle races with listening socket close when connecting a unix socket. PR: 211531 Changes: _U stable/10/ stable/10/sys/kern/uipc_usrreq.c stable/10/sys/sys/unpcb.h |
I encountered a double lock issue in unp_connectat function. After looking at the code , I think the unp_link_rwlock is being locked once unp_connectat and once again in unp_detach (called from sofree ). Below is the exact call stack. UNP_LINK_WLOCK(); <—————————— 1 st call ….. ….. if (so->so_proto->pr_flags & PR_CONNREQUIRED) { if (so2->so_options & SO_ACCEPTCONN CURVNET_SET(so2->so_vnet); so3 = sonewconn(so2, 0); // Expanding sonewconn { sonewconn { …… soalloc ……. pru_attach ……. if (!(head->so_options & SO_ACCEPTCONN) && ((head->so_proto->pr_protocol != IPPROTO_SCTP) || (head->so_type != SOCK_SEQPACKET))) { ………. sofree(so); /* NB: returns ACCEPT_UNLOCK'ed. */ // Expanding sofree { ……. pru_detach // expanding pru_detach { // Recursive wlock acquiring. UNP_LINK_WLOCK() <—————————— 2nd Call ------------------------------------------------ Backtrace: #0 doadump (textdump=1) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/kern_shutdown.c:269 #1 0xffffffff8041084f in kern_reboot (howto=260) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/kern_shutdown.c:452 #2 0xffffffff80410d32 in vpanic (fmt=<value optimized out>, ap=<value optimized out>) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/kern_shutdown.c:759 #3 0xffffffff80410f23 in kassert_panic (fmt=0xffffffff805e4300 "%s: recursing but non-recursive rw %s @ %s:%d\n") at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/kern_shutdown.c:647 #4 0xffffffff8040e2c5 in __rw_wlock_hard (c=<value optimized out>, tid=18446735292422403312, file=0x0, line=0) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/kern_rwlock.c:739 #5 0xffffffff8040ed21 in _rw_wlock_cookie (c=<value optimized out>, file=0xffffffff805f4e20 "/.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/uipc_usrreq.c", line=654) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/kern_rwlock.c:267 #6 0xffffffff8049b1c4 in uipc_detach (so=<value optimized out>) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/uipc_usrreq.c:654 #7 0xffffffff80490203 in sofree (so=0xfffff80372dc5000) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/uipc_socket.c:791 #8 0xffffffff80490c21 in sonewconn (head=0xfffff80735e98000, connstatus=0) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/uipc_socket.c:617 #9 0xffffffff80498f79 in unp_connectat (fd=<value optimized out>, so=0xfffff8066ee292e0, nam=<value optimized out>, td=0xfffff803727fb4f0) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/uipc_usrreq.c:1359 #10 0xffffffff8049c0c1 in uipc_connect (so=0xfffff8066ee292e0, nam=0xfffffe085d25d170, td=0xfffff803727fb4f0) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/kern/uipc_usrreq.c:585 #11 0xffffffff83879e5a in clnt_vc_create (so=0xfffff8066ee292e0, raddr=<value optimized out>, prog=100000, vers=3, sendsz=9000, recvsz=9000, intrflag=1) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/rpc/clnt_vc.c:154 #12 0xffffffff8387caa6 in local_rpcb () at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/rpc/rpcb_clnt.c:461 #13 0xffffffff8387cb0d in rpcb_unset (program=0, version=0, nconf=0x0) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/rpc/rpcb_clnt.c:616 #14 0xffffffff8387f57c in svc_unreg (pool=0xfffffe0003d27000, prog=100003, vers=2) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/rpc/svc.c:532 #15 0xffffffff8387f991 in svcpool_destroy (pool=0xfffffe0003d27000) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/rpc/svc.c:204 #16 0xffffffff838c3cf9 in nfsrvd_init (terminating=<value optimized out>) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/fs/nfsserver/nfs_nfsdkrpc.c:539 #17 0xffffffff838c490b in nfsrvd_nfsd (td=<value optimized out>, args=0xfffffe085d25da70) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/fs/nfsserver/nfs_nfsdkrpc.c:516 #18 0xffffffff838d4f9b in nfssvc_nfsd (td=0xfffff803727fb4f0, uap=<value optimized out>) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/fs/nfsserver/nfs_nfsdport.c:3081 #19 0xffffffff838b111b in sys_nfssvc (td=0xfffff803727fb4f0, uap=0xfffffe085d25db70) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/nfs/nfs_nfssvc.c:108 #20 0xffffffff805597a6 in amd64_syscall (td=0xfffff803727fb4f0, traced=0) at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/amd64/amd64/../../kern/subr_syscall.c:145 #21 0xffffffff8053e647 in Xfast_syscall () at /.amd/svl-engdata1vs1/occamdev/build/freebsd/stable_10/20160419.182836_fbsd-builder_10.325814/src/sys/amd64/amd64/exception.S:396 #22 0x0000000800a915fa in ?? () Backtrace stopped: previous frame inner to this frame (corrupt stack?) I am working on a patch for the fix