On 08/08/17 10:06, Ben RUBSON wrote:
On 08 Aug 2017, at 10:02, Hans Petter Selasky <h...@selasky.org> wrote:
On 08/08/17 10:00, Ben RUBSON wrote:
kgdb) print *twq_2msl.tqh_first
$2 = {
tw_inpcb = 0xfffff8031c570740,
print *twq_2msl.tqh_first->tw_inpcb
(kgdb) print *twq_2msl.tqh_first->tw_inpcb
$3 = {
inp_hash = {
le_next = 0x0,
le_prev = 0xfffffe000f78adb8
},
inp_pcbgrouphash = {
le_next = 0x0,
le_prev = 0x0
},
inp_list = {
le_next = 0xfffff80c2a07f570,
le_prev = 0xffffffff81e15e20
},
inp_ppcb = 0xfffff80d1bf12210,
inp_pcbinfo = 0xffffffff81e15e28,
inp_pcbgroup = 0x0,
inp_pcbgroup_wild = {
le_next = 0x0,
le_prev = 0x0
},
inp_socket = 0x0,
inp_cred = 0xfffff804ae6ca400,
inp_flow = 0,
inp_flags = 92274688,
inp_flags2 = 16,
inp_vflag = 0 '\0',
inp_ip_ttl = 64 '@',
inp_ip_p = 0 '\0',
inp_ip_minttl = 0 '\0',
inp_flowid = 946611505,
inp_refcount = 2,
inp_pspare = 0xfffff8031c5707c0,
inp_flowtype = 191,
inp_rss_listen_bucket = 0,
inp_ispare = 0xfffff8031c5707f0,
inp_inc = {
inc_flags = 0 '\0',
inc_len = 0 '\0',
inc_fibnum = 0,
inc_ie = {
ie_fport = 53987,
ie_lport = 47873,
ie_dependfaddr = {
ie46_foreign = {
ia46_pad32 = 0xfffff8031c570808,
ia46_addr4 = {
s_addr = 3011802202
}
},
ie6_foreign = {
__u6_addr = {
__u6_addr8 = 0xfffff8031c570808 "",
__u6_addr16 = 0xfffff8031c570808,
__u6_addr32 = 0xfffff8031c570808
}
}
},
ie_dependladdr = {
ie46_local = {
ia46_pad32 = 0xfffff8031c570818,
ia46_addr4 = {
s_addr = 4068705883
}
},
ie6_local = {
__u6_addr = {
__u6_addr8 = 0xfffff8031c570818 "",
__u6_addr16 = 0xfffff8031c570818,
__u6_addr32 = 0xfffff8031c570818
}
}
},
ie6_zoneid = 0
}
},
inp_label = 0x0,
inp_sp = 0x0,
inp_depend4 = {
inp4_ip_tos = 0 '\0',
inp4_options = 0x0,
inp4_moptions = 0x0
},
inp_depend6 = {
inp6_options = 0x0,
inp6_outputopts = 0x0,
inp6_moptions = 0x0,
inp6_icmp6filt = 0x0,
inp6_cksum = 0,
inp6_hops = 0
},
inp_portlist = {
le_next = 0xfffff80274298ae0,
le_prev = 0xfffff800454999b0
},
inp_phd = 0xfffff800454999a0,
inp_gencnt = 2119756,
inp_lle = 0x0,
inp_lock = {
lock_object = {
lo_name = 0xffffffff814e6940 "tcpinp",
lo_flags = 90898432,
lo_data = 0,
lo_witness = 0x0
},
rw_lock = 18446735277871559936
},
inp_rt_cookie = 10,
inp_rtu = {
inpu_route = {
ro_rt = 0x0,
ro_lle = 0x0,
ro_prepend = 0x0,
ro_plen = 0,
ro_flags = 384,
ro_mtu = 0,
spare = 0,
ro_dst = {
sa_len = 16 '\020',
sa_family = 2 '\002',
sa_data = 0xfffff8031c5708f2 ""
}
},
inpu_route6 = {
ro_rt = 0x0,
ro_lle = 0x0,
ro_prepend = 0x0,
ro_plen = 0,
ro_flags = 384,
ro_mtu = 0,
spare = 0,
ro_dst = {
sin6_len = 16 '\020',
sin6_family = 2 '\002',
sin6_port = 0,
sin6_flowinfo = 3011802202,
sin6_addr = {
__u6_addr = {
__u6_addr8 = 0xfffff8031c5708f8 "",
__u6_addr16 = 0xfffff8031c5708f8,
__u6_addr32 = 0xfffff8031c5708f8
}
},
sin6_scope_id = 0
}
}
}
}
(kgdb)
Hi,
Here is the conclusion:
The following code is going in an infinite loop:
for (;;) {
TW_RLOCK(V_tw_lock);
tw = TAILQ_FIRST(&V_twq_2msl);
if (tw == NULL || (!reuse && (tw->tw_time - ticks) > 0)) {
TW_RUNLOCK(V_tw_lock);
break;
}
KASSERT(tw->tw_inpcb != NULL, ("%s: tw->tw_inpcb == NULL",
__func__));
inp = tw->tw_inpcb;
in_pcbref(inp);
TW_RUNLOCK(V_tw_lock);
if (INP_INFO_TRY_RLOCK(&V_tcbinfo)) {
INP_WLOCK(inp);
tw = intotw(inp);
if (in_pcbrele_wlocked(inp)) {
in_pcbrele_wlocked() returns (1) because INP_FREED (16) is set in
inp->inp_flags2. I guess you have invariants disabled, because the
KASSERT() below should have caused a panic.
KASSERT(tw == NULL, ("%s: held last inp "
"reference but tw not NULL", __func__));
INP_INFO_RUNLOCK(&V_tcbinfo);
continue;
}
This is a regression issue after:
commit 5630210a7f1dbbd903b77b2aef939cd47c63da58
Author: jch <j...@freebsd.org>
Date: Thu Oct 30 08:53:56 2014 +0000
Fix a race condition in TCP timewait between tcp_tw_2msl_reuse() and
tcp_tw_2msl_scan(). This race condition drives unplanned timewait
timeout cancellation. Also simplify implementation by holding inpcb
reference and removing tcptw reference counting.
Suggested fix attached.
--HPS
Index: sys/netinet/tcp_timewait.c
===================================================================
--- sys/netinet/tcp_timewait.c (revision 321981)
+++ sys/netinet/tcp_timewait.c (working copy)
@@ -709,10 +709,11 @@
INP_WLOCK(inp);
tw = intotw(inp);
if (in_pcbrele_wlocked(inp)) {
- KASSERT(tw == NULL, ("%s: held last inp "
- "reference but tw not NULL", __func__));
INP_INFO_RUNLOCK(&V_tcbinfo);
- continue;
+ if (tw == NULL)
+ continue;
+ else
+ break; /* INP_FREED flag is set */
}
if (tw == NULL) {
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