Author: jch
Date: Thu Jun 11 13:44:06 2015
New Revision: 284261
URL: https://svnweb.freebsd.org/changeset/base/284261
Log:
MFC r284245:
Fix a callout race condition introduced in TCP timers callouts with r281599.
In TCP timer context, it is not enough to check callout_stop() return value
to decide if a callout is still running or not, previous callout_reset()
return values have also to be checked.
Modified:
stable/10/sys/netinet/tcp_timer.c
stable/10/sys/netinet/tcp_timer.h
Directory Properties:
stable/10/ (props changed)
Modified: stable/10/sys/netinet/tcp_timer.c
==============================================================================
--- stable/10/sys/netinet/tcp_timer.c Thu Jun 11 13:26:16 2015
(r284260)
+++ stable/10/sys/netinet/tcp_timer.c Thu Jun 11 13:44:06 2015
(r284261)
@@ -298,10 +298,12 @@ tcp_timer_2msl(void *xtp)
tp = tcp_close(tp);
} else {
if (tp->t_state != TCPS_TIME_WAIT &&
- ticks - tp->t_rcvtime <= TP_MAXIDLE(tp))
- callout_reset_on(&tp->t_timers->tt_2msl,
- TP_KEEPINTVL(tp), tcp_timer_2msl, tp, INP_CPU(inp));
- else
+ ticks - tp->t_rcvtime <= TP_MAXIDLE(tp)) {
+ if (!callout_reset(&tp->t_timers->tt_2msl,
+ TP_KEEPINTVL(tp), tcp_timer_2msl, tp)) {
+ tp->t_timers->tt_flags &= ~TT_2MSL_RST;
+ }
+ } else
tp = tcp_close(tp);
}
@@ -381,11 +383,14 @@ tcp_timer_keep(void *xtp)
tp->rcv_nxt, tp->snd_una - 1, 0);
free(t_template, M_TEMP);
}
- callout_reset_on(&tp->t_timers->tt_keep, TP_KEEPINTVL(tp),
- tcp_timer_keep, tp, INP_CPU(inp));
- } else
- callout_reset_on(&tp->t_timers->tt_keep, TP_KEEPIDLE(tp),
- tcp_timer_keep, tp, INP_CPU(inp));
+ if (!callout_reset(&tp->t_timers->tt_keep, TP_KEEPINTVL(tp),
+ tcp_timer_keep, tp)) {
+ tp->t_timers->tt_flags &= ~TT_KEEP_RST;
+ }
+ } else if (!callout_reset(&tp->t_timers->tt_keep, TP_KEEPIDLE(tp),
+ tcp_timer_keep, tp)) {
+ tp->t_timers->tt_flags &= ~TT_KEEP_RST;
+ }
#ifdef TCPDEBUG
if (inp->inp_socket->so_options & SO_DEBUG)
@@ -760,6 +765,7 @@ tcp_timer_activate(struct tcpcb *tp, uin
timeout_t *f_callout;
struct inpcb *inp = tp->t_inpcb;
int cpu = INP_CPU(inp);
+ uint32_t f_reset;
#ifdef TCP_OFFLOAD
if (tp->t_flags & TF_TOE)
@@ -773,38 +779,49 @@ tcp_timer_activate(struct tcpcb *tp, uin
case TT_DELACK:
t_callout = &tp->t_timers->tt_delack;
f_callout = tcp_timer_delack;
+ f_reset = TT_DELACK_RST;
break;
case TT_REXMT:
t_callout = &tp->t_timers->tt_rexmt;
f_callout = tcp_timer_rexmt;
+ f_reset = TT_REXMT_RST;
break;
case TT_PERSIST:
t_callout = &tp->t_timers->tt_persist;
f_callout = tcp_timer_persist;
+ f_reset = TT_PERSIST_RST;
break;
case TT_KEEP:
t_callout = &tp->t_timers->tt_keep;
f_callout = tcp_timer_keep;
+ f_reset = TT_KEEP_RST;
break;
case TT_2MSL:
t_callout = &tp->t_timers->tt_2msl;
f_callout = tcp_timer_2msl;
+ f_reset = TT_2MSL_RST;
break;
default:
panic("tp %p bad timer_type %#x", tp, timer_type);
}
if (delta == 0) {
if ((tp->t_timers->tt_flags & timer_type) &&
- callout_stop(t_callout)) {
- tp->t_timers->tt_flags &= ~timer_type;
+ callout_stop(t_callout) &&
+ (tp->t_timers->tt_flags & f_reset)) {
+ tp->t_timers->tt_flags &= ~(timer_type | f_reset);
}
} else {
if ((tp->t_timers->tt_flags & timer_type) == 0) {
- tp->t_timers->tt_flags |= timer_type;
+ tp->t_timers->tt_flags |= (timer_type | f_reset);
callout_reset_on(t_callout, delta, f_callout, tp, cpu);
} else {
/* Reset already running callout on the same CPU. */
- callout_reset(t_callout, delta, f_callout, tp);
+ if (!callout_reset(t_callout, delta, f_callout, tp)) {
+ /*
+ * Callout not cancelled, consider it as not
+ * properly restarted. */
+ tp->t_timers->tt_flags &= ~f_reset;
+ }
}
}
}
@@ -841,6 +858,7 @@ tcp_timer_stop(struct tcpcb *tp, uint32_
{
struct callout *t_callout;
timeout_t *f_callout;
+ uint32_t f_reset;
tp->t_timers->tt_flags |= TT_STOPPED;
@@ -848,30 +866,36 @@ tcp_timer_stop(struct tcpcb *tp, uint32_
case TT_DELACK:
t_callout = &tp->t_timers->tt_delack;
f_callout = tcp_timer_delack_discard;
+ f_reset = TT_DELACK_RST;
break;
case TT_REXMT:
t_callout = &tp->t_timers->tt_rexmt;
f_callout = tcp_timer_rexmt_discard;
+ f_reset = TT_REXMT_RST;
break;
case TT_PERSIST:
t_callout = &tp->t_timers->tt_persist;
f_callout = tcp_timer_persist_discard;
+ f_reset = TT_PERSIST_RST;
break;
case TT_KEEP:
t_callout = &tp->t_timers->tt_keep;
f_callout = tcp_timer_keep_discard;
+ f_reset = TT_KEEP_RST;
break;
case TT_2MSL:
t_callout = &tp->t_timers->tt_2msl;
f_callout = tcp_timer_2msl_discard;
+ f_reset = TT_2MSL_RST;
break;
default:
panic("tp %p bad timer_type %#x", tp, timer_type);
}
if (tp->t_timers->tt_flags & timer_type) {
- if (callout_stop(t_callout)) {
- tp->t_timers->tt_flags &= ~timer_type;
+ if (callout_stop(t_callout) &&
+ (tp->t_timers->tt_flags & f_reset)) {
+ tp->t_timers->tt_flags &= ~(timer_type | f_reset);
} else {
/*
* Can't stop the callout, defer tcpcb actual deletion
Modified: stable/10/sys/netinet/tcp_timer.h
==============================================================================
--- stable/10/sys/netinet/tcp_timer.h Thu Jun 11 13:26:16 2015
(r284260)
+++ stable/10/sys/netinet/tcp_timer.h Thu Jun 11 13:44:06 2015
(r284261)
@@ -160,6 +160,12 @@ struct tcp_timer {
#define TT_2MSL 0x0010
#define TT_MASK (TT_DELACK|TT_REXMT|TT_PERSIST|TT_KEEP|TT_2MSL)
+#define TT_DELACK_RST 0x0100
+#define TT_REXMT_RST 0x0200
+#define TT_PERSIST_RST 0x0400
+#define TT_KEEP_RST 0x0800
+#define TT_2MSL_RST 0x1000
+
#define TT_STOPPED 0x00010000
#define TP_KEEPINIT(tp) ((tp)->t_keepinit ? (tp)->t_keepinit :
tcp_keepinit)
_______________________________________________
[email protected] mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-stable-10
To unsubscribe, send any mail to "[email protected]"
