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Message-Id: <bca565004b9fd7ff7aba09f41aa65dab2085154b.1592338450.git.dcaratti@redhat.com>
Date: Tue, 16 Jun 2020 22:25:21 +0200
From: Davide Caratti <dcaratti@...hat.com>
To: Po Liu <Po.Liu@....com>, Cong Wang <xiyou.wangcong@...il.com>,
Vladimir Oltean <olteanv@...il.com>
Cc: "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org
Subject: [PATCH net v3 2/2] net/sched: act_gate: fix configuration of the periodic timer
assigning a dummy value of 'clock_id' to avoid cancellation of the cycle
timer before its initialization was a temporary solution, and we still
need to handle the case where act_gate timer parameters are changed by
commands like the following one:
# tc action replace action gate <parameters>
the fix consists in the following items:
1) remove the workaround assignment of 'clock_id', and init the list of
entries before the first error path after IDR atomic check/allocation
2) validate 'clock_id' earlier: there is no need to do IDR atomic
check/allocation if we know that 'clock_id' is a bad value
3) use a dedicated function, 'gate_setup_timer()', to ensure that the
timer is cancelled and re-initialized on action overwrite, and also
ensure we initialize the timer in the error path of tcf_gate_init()
v3: improve comment in the error path of tcf_gate_init() (thanks to
Vladimir Oltean)
v2: avoid 'goto' in gate_setup_timer (thanks to Cong Wang)
CC: Ivan Vecera <ivecera@...hat.com>
Fixes: a01c245438c5 ("net/sched: fix a couple of splats in the error path of tfc_gate_init()")
Fixes: a51c328df310 ("net: qos: introduce a gate control flow action")
Signed-off-by: Davide Caratti <dcaratti@...hat.com>
---
net/sched/act_gate.c | 90 +++++++++++++++++++++++++++-----------------
1 file changed, 55 insertions(+), 35 deletions(-)
diff --git a/net/sched/act_gate.c b/net/sched/act_gate.c
index 94e560c2f81d..323ae7f6315d 100644
--- a/net/sched/act_gate.c
+++ b/net/sched/act_gate.c
@@ -272,6 +272,27 @@ static int parse_gate_list(struct nlattr *list_attr,
return err;
}
+static void gate_setup_timer(struct tcf_gate *gact, u64 basetime,
+ enum tk_offsets tko, s32 clockid,
+ bool do_init)
+{
+ if (!do_init) {
+ if (basetime == gact->param.tcfg_basetime &&
+ tko == gact->tk_offset &&
+ clockid == gact->param.tcfg_clockid)
+ return;
+
+ spin_unlock_bh(&gact->tcf_lock);
+ hrtimer_cancel(&gact->hitimer);
+ spin_lock_bh(&gact->tcf_lock);
+ }
+ gact->param.tcfg_basetime = basetime;
+ gact->param.tcfg_clockid = clockid;
+ gact->tk_offset = tko;
+ hrtimer_init(&gact->hitimer, clockid, HRTIMER_MODE_ABS_SOFT);
+ gact->hitimer.function = gate_timer_func;
+}
+
static int tcf_gate_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
int ovr, int bind, bool rtnl_held,
@@ -303,6 +324,27 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
if (!tb[TCA_GATE_PARMS])
return -EINVAL;
+ if (tb[TCA_GATE_CLOCKID]) {
+ clockid = nla_get_s32(tb[TCA_GATE_CLOCKID]);
+ switch (clockid) {
+ case CLOCK_REALTIME:
+ tk_offset = TK_OFFS_REAL;
+ break;
+ case CLOCK_MONOTONIC:
+ tk_offset = TK_OFFS_MAX;
+ break;
+ case CLOCK_BOOTTIME:
+ tk_offset = TK_OFFS_BOOT;
+ break;
+ case CLOCK_TAI:
+ tk_offset = TK_OFFS_TAI;
+ break;
+ default:
+ NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
+ return -EINVAL;
+ }
+ }
+
parm = nla_data(tb[TCA_GATE_PARMS]);
index = parm->index;
@@ -326,10 +368,6 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
tcf_idr_release(*a, bind);
return -EEXIST;
}
- if (ret == ACT_P_CREATED) {
- to_gate(*a)->param.tcfg_clockid = -1;
- INIT_LIST_HEAD(&(to_gate(*a)->param.entries));
- }
if (tb[TCA_GATE_PRIORITY])
prio = nla_get_s32(tb[TCA_GATE_PRIORITY]);
@@ -340,33 +378,14 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
if (tb[TCA_GATE_FLAGS])
gflags = nla_get_u32(tb[TCA_GATE_FLAGS]);
- if (tb[TCA_GATE_CLOCKID]) {
- clockid = nla_get_s32(tb[TCA_GATE_CLOCKID]);
- switch (clockid) {
- case CLOCK_REALTIME:
- tk_offset = TK_OFFS_REAL;
- break;
- case CLOCK_MONOTONIC:
- tk_offset = TK_OFFS_MAX;
- break;
- case CLOCK_BOOTTIME:
- tk_offset = TK_OFFS_BOOT;
- break;
- case CLOCK_TAI:
- tk_offset = TK_OFFS_TAI;
- break;
- default:
- NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
- goto release_idr;
- }
- }
+ gact = to_gate(*a);
+ if (ret == ACT_P_CREATED)
+ INIT_LIST_HEAD(&gact->param.entries);
err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
if (err < 0)
goto release_idr;
- gact = to_gate(*a);
-
spin_lock_bh(&gact->tcf_lock);
p = &gact->param;
@@ -397,14 +416,10 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
p->tcfg_cycletime_ext =
nla_get_u64(tb[TCA_GATE_CYCLE_TIME_EXT]);
+ gate_setup_timer(gact, basetime, tk_offset, clockid,
+ ret == ACT_P_CREATED);
p->tcfg_priority = prio;
- p->tcfg_basetime = basetime;
- p->tcfg_clockid = clockid;
p->tcfg_flags = gflags;
-
- gact->tk_offset = tk_offset;
- hrtimer_init(&gact->hitimer, clockid, HRTIMER_MODE_ABS_SOFT);
- gact->hitimer.function = gate_timer_func;
gate_get_start_time(gact, &start);
gact->current_close_time = start;
@@ -433,6 +448,13 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
release_idr:
+ /* action is not inserted in any list: it's safe to init hitimer
+ * without taking tcf_lock.
+ */
+ if (ret == ACT_P_CREATED)
+ gate_setup_timer(gact, gact->param.tcfg_basetime,
+ gact->tk_offset, gact->param.tcfg_clockid,
+ true);
tcf_idr_release(*a, bind);
return err;
}
@@ -443,9 +465,7 @@ static void tcf_gate_cleanup(struct tc_action *a)
struct tcf_gate_params *p;
p = &gact->param;
- if (p->tcfg_clockid != -1)
- hrtimer_cancel(&gact->hitimer);
-
+ hrtimer_cancel(&gact->hitimer);
release_entry_list(&p->entries);
}
--
2.26.2
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