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net/sched: act_gate: snapshot parameters with RCU on replace
The gate action can be replaced while the hrtimer callback or dump path is
walking the schedule list.
Convert the parameters to an RCU-protected snapshot and swap updates under
tcf_lock, freeing the previous snapshot via call_rcu(). When REPLACE omits
the entry list, preserve the existing schedule so the effective state is
unchanged.
Fixes: a51c328df3 ("net: qos: introduce a gate control flow action")
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moses <p@1g4.org>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20260223150512.2251594-2-p@1g4.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Paul Moses
Jakub Kicinski
parent
be11a53722
commit
62413a9c3c
2 changed files with 213 additions and 87 deletions
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@ -32,9 +32,12 @@ static ktime_t gate_get_time(struct tcf_gate *gact)
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return KTIME_MAX;
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}
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static void gate_get_start_time(struct tcf_gate *gact, ktime_t *start)
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static void tcf_gate_params_free_rcu(struct rcu_head *head);
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static void gate_get_start_time(struct tcf_gate *gact,
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const struct tcf_gate_params *param,
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ktime_t *start)
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{
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struct tcf_gate_params *param = &gact->param;
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ktime_t now, base, cycle;
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u64 n;
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@ -69,12 +72,14 @@ static enum hrtimer_restart gate_timer_func(struct hrtimer *timer)
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{
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struct tcf_gate *gact = container_of(timer, struct tcf_gate,
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hitimer);
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struct tcf_gate_params *p = &gact->param;
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struct tcfg_gate_entry *next;
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struct tcf_gate_params *p;
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ktime_t close_time, now;
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spin_lock(&gact->tcf_lock);
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p = rcu_dereference_protected(gact->param,
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lockdep_is_held(&gact->tcf_lock));
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next = gact->next_entry;
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/* cycle start, clear pending bit, clear total octets */
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@ -225,6 +230,35 @@ static void release_entry_list(struct list_head *entries)
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}
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}
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static int tcf_gate_copy_entries(struct tcf_gate_params *dst,
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const struct tcf_gate_params *src,
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struct netlink_ext_ack *extack)
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{
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struct tcfg_gate_entry *entry;
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int i = 0;
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list_for_each_entry(entry, &src->entries, list) {
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struct tcfg_gate_entry *new;
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new = kzalloc(sizeof(*new), GFP_ATOMIC);
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if (!new) {
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NL_SET_ERR_MSG(extack, "Not enough memory for entry");
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return -ENOMEM;
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}
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new->index = entry->index;
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new->gate_state = entry->gate_state;
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new->interval = entry->interval;
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new->ipv = entry->ipv;
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new->maxoctets = entry->maxoctets;
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list_add_tail(&new->list, &dst->entries);
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i++;
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}
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dst->num_entries = i;
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return 0;
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}
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static int parse_gate_list(struct nlattr *list_attr,
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struct tcf_gate_params *sched,
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struct netlink_ext_ack *extack)
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@ -270,24 +304,44 @@ release_list:
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return err;
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}
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static void gate_setup_timer(struct tcf_gate *gact, u64 basetime,
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enum tk_offsets tko, s32 clockid,
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bool do_init)
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static bool gate_timer_needs_cancel(u64 basetime, u64 old_basetime,
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enum tk_offsets tko,
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enum tk_offsets old_tko,
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s32 clockid, s32 old_clockid)
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{
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if (!do_init) {
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if (basetime == gact->param.tcfg_basetime &&
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tko == gact->tk_offset &&
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clockid == gact->param.tcfg_clockid)
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return;
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return basetime != old_basetime ||
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clockid != old_clockid ||
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tko != old_tko;
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}
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spin_unlock_bh(&gact->tcf_lock);
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hrtimer_cancel(&gact->hitimer);
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spin_lock_bh(&gact->tcf_lock);
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static int gate_clock_resolve(s32 clockid, enum tk_offsets *tko,
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struct netlink_ext_ack *extack)
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{
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switch (clockid) {
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case CLOCK_REALTIME:
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*tko = TK_OFFS_REAL;
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return 0;
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case CLOCK_MONOTONIC:
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*tko = TK_OFFS_MAX;
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return 0;
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case CLOCK_BOOTTIME:
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*tko = TK_OFFS_BOOT;
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return 0;
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case CLOCK_TAI:
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*tko = TK_OFFS_TAI;
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return 0;
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default:
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NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
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return -EINVAL;
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}
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gact->param.tcfg_basetime = basetime;
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gact->param.tcfg_clockid = clockid;
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gact->tk_offset = tko;
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hrtimer_setup(&gact->hitimer, gate_timer_func, clockid, HRTIMER_MODE_ABS_SOFT);
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}
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static void gate_setup_timer(struct tcf_gate *gact, s32 clockid,
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enum tk_offsets tko)
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{
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WRITE_ONCE(gact->tk_offset, tko);
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hrtimer_setup(&gact->hitimer, gate_timer_func, clockid,
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HRTIMER_MODE_ABS_SOFT);
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}
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static int tcf_gate_init(struct net *net, struct nlattr *nla,
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@ -296,15 +350,22 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
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struct netlink_ext_ack *extack)
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{
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struct tc_action_net *tn = net_generic(net, act_gate_ops.net_id);
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enum tk_offsets tk_offset = TK_OFFS_TAI;
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u64 cycletime = 0, basetime = 0, cycletime_ext = 0;
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struct tcf_gate_params *p = NULL, *old_p = NULL;
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enum tk_offsets old_tk_offset = TK_OFFS_TAI;
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const struct tcf_gate_params *cur_p = NULL;
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bool bind = flags & TCA_ACT_FLAGS_BIND;
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struct nlattr *tb[TCA_GATE_MAX + 1];
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enum tk_offsets tko = TK_OFFS_TAI;
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struct tcf_chain *goto_ch = NULL;
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u64 cycletime = 0, basetime = 0;
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struct tcf_gate_params *p;
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s32 timer_clockid = CLOCK_TAI;
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bool use_old_entries = false;
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s32 old_clockid = CLOCK_TAI;
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bool need_cancel = false;
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s32 clockid = CLOCK_TAI;
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struct tcf_gate *gact;
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struct tc_gate *parm;
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u64 old_basetime = 0;
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int ret = 0, err;
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u32 gflags = 0;
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s32 prio = -1;
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@ -321,26 +382,8 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
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if (!tb[TCA_GATE_PARMS])
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return -EINVAL;
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if (tb[TCA_GATE_CLOCKID]) {
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if (tb[TCA_GATE_CLOCKID])
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clockid = nla_get_s32(tb[TCA_GATE_CLOCKID]);
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switch (clockid) {
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case CLOCK_REALTIME:
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tk_offset = TK_OFFS_REAL;
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break;
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case CLOCK_MONOTONIC:
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tk_offset = TK_OFFS_MAX;
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break;
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case CLOCK_BOOTTIME:
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tk_offset = TK_OFFS_BOOT;
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break;
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case CLOCK_TAI:
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tk_offset = TK_OFFS_TAI;
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break;
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default:
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NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
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return -EINVAL;
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}
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}
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parm = nla_data(tb[TCA_GATE_PARMS]);
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index = parm->index;
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@ -366,6 +409,60 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
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return -EEXIST;
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}
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gact = to_gate(*a);
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err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
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if (err < 0)
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goto release_idr;
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p = kzalloc(sizeof(*p), GFP_KERNEL);
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if (!p) {
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err = -ENOMEM;
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goto chain_put;
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}
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INIT_LIST_HEAD(&p->entries);
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use_old_entries = !tb[TCA_GATE_ENTRY_LIST];
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if (!use_old_entries) {
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err = parse_gate_list(tb[TCA_GATE_ENTRY_LIST], p, extack);
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if (err < 0)
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goto err_free;
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use_old_entries = !err;
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}
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if (ret == ACT_P_CREATED && use_old_entries) {
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NL_SET_ERR_MSG(extack, "The entry list is empty");
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err = -EINVAL;
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goto err_free;
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}
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if (ret != ACT_P_CREATED) {
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rcu_read_lock();
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cur_p = rcu_dereference(gact->param);
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old_basetime = cur_p->tcfg_basetime;
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old_clockid = cur_p->tcfg_clockid;
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old_tk_offset = READ_ONCE(gact->tk_offset);
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basetime = old_basetime;
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cycletime_ext = cur_p->tcfg_cycletime_ext;
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prio = cur_p->tcfg_priority;
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gflags = cur_p->tcfg_flags;
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if (!tb[TCA_GATE_CLOCKID])
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clockid = old_clockid;
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err = 0;
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if (use_old_entries) {
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err = tcf_gate_copy_entries(p, cur_p, extack);
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if (!err && !tb[TCA_GATE_CYCLE_TIME])
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cycletime = cur_p->tcfg_cycletime;
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}
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rcu_read_unlock();
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if (err)
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goto err_free;
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}
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if (tb[TCA_GATE_PRIORITY])
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prio = nla_get_s32(tb[TCA_GATE_PRIORITY]);
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@ -375,25 +472,26 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
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if (tb[TCA_GATE_FLAGS])
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gflags = nla_get_u32(tb[TCA_GATE_FLAGS]);
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gact = to_gate(*a);
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if (ret == ACT_P_CREATED)
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INIT_LIST_HEAD(&gact->param.entries);
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err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
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if (err < 0)
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goto release_idr;
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spin_lock_bh(&gact->tcf_lock);
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p = &gact->param;
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if (tb[TCA_GATE_CYCLE_TIME])
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cycletime = nla_get_u64(tb[TCA_GATE_CYCLE_TIME]);
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if (tb[TCA_GATE_ENTRY_LIST]) {
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err = parse_gate_list(tb[TCA_GATE_ENTRY_LIST], p, extack);
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if (err < 0)
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goto chain_put;
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}
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if (tb[TCA_GATE_CYCLE_TIME_EXT])
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cycletime_ext = nla_get_u64(tb[TCA_GATE_CYCLE_TIME_EXT]);
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err = gate_clock_resolve(clockid, &tko, extack);
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if (err)
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goto err_free;
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timer_clockid = clockid;
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need_cancel = ret != ACT_P_CREATED &&
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gate_timer_needs_cancel(basetime, old_basetime,
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tko, old_tk_offset,
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timer_clockid, old_clockid);
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if (need_cancel)
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hrtimer_cancel(&gact->hitimer);
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spin_lock_bh(&gact->tcf_lock);
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if (!cycletime) {
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struct tcfg_gate_entry *entry;
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@ -402,22 +500,20 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
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list_for_each_entry(entry, &p->entries, list)
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cycle = ktime_add_ns(cycle, entry->interval);
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cycletime = cycle;
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if (!cycletime) {
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err = -EINVAL;
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goto chain_put;
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}
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}
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p->tcfg_cycletime = cycletime;
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p->tcfg_cycletime_ext = cycletime_ext;
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if (tb[TCA_GATE_CYCLE_TIME_EXT])
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p->tcfg_cycletime_ext =
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nla_get_u64(tb[TCA_GATE_CYCLE_TIME_EXT]);
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gate_setup_timer(gact, basetime, tk_offset, clockid,
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ret == ACT_P_CREATED);
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if (need_cancel || ret == ACT_P_CREATED)
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gate_setup_timer(gact, timer_clockid, tko);
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p->tcfg_priority = prio;
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p->tcfg_flags = gflags;
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gate_get_start_time(gact, &start);
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p->tcfg_basetime = basetime;
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p->tcfg_clockid = timer_clockid;
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gate_get_start_time(gact, p, &start);
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old_p = rcu_replace_pointer(gact->param, p,
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lockdep_is_held(&gact->tcf_lock));
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gact->current_close_time = start;
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gact->current_gate_status = GATE_ACT_GATE_OPEN | GATE_ACT_PENDING;
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@ -434,11 +530,15 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
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if (goto_ch)
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tcf_chain_put_by_act(goto_ch);
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if (old_p)
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call_rcu(&old_p->rcu, tcf_gate_params_free_rcu);
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return ret;
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err_free:
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release_entry_list(&p->entries);
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kfree(p);
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chain_put:
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spin_unlock_bh(&gact->tcf_lock);
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if (goto_ch)
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tcf_chain_put_by_act(goto_ch);
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release_idr:
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@ -446,21 +546,29 @@ release_idr:
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* without taking tcf_lock.
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*/
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if (ret == ACT_P_CREATED)
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gate_setup_timer(gact, gact->param.tcfg_basetime,
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gact->tk_offset, gact->param.tcfg_clockid,
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true);
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gate_setup_timer(gact, timer_clockid, tko);
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tcf_idr_release(*a, bind);
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return err;
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}
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static void tcf_gate_params_free_rcu(struct rcu_head *head)
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{
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struct tcf_gate_params *p = container_of(head, struct tcf_gate_params, rcu);
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release_entry_list(&p->entries);
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kfree(p);
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}
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static void tcf_gate_cleanup(struct tc_action *a)
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{
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struct tcf_gate *gact = to_gate(a);
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struct tcf_gate_params *p;
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p = &gact->param;
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hrtimer_cancel(&gact->hitimer);
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release_entry_list(&p->entries);
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p = rcu_dereference_protected(gact->param, 1);
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if (p)
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call_rcu(&p->rcu, tcf_gate_params_free_rcu);
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}
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static int dumping_entry(struct sk_buff *skb,
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@ -509,10 +617,9 @@ static int tcf_gate_dump(struct sk_buff *skb, struct tc_action *a,
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struct nlattr *entry_list;
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struct tcf_t t;
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spin_lock_bh(&gact->tcf_lock);
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opt.action = gact->tcf_action;
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p = &gact->param;
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rcu_read_lock();
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opt.action = READ_ONCE(gact->tcf_action);
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p = rcu_dereference(gact->param);
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if (nla_put(skb, TCA_GATE_PARMS, sizeof(opt), &opt))
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goto nla_put_failure;
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@ -552,12 +659,12 @@ static int tcf_gate_dump(struct sk_buff *skb, struct tc_action *a,
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tcf_tm_dump(&t, &gact->tcf_tm);
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if (nla_put_64bit(skb, TCA_GATE_TM, sizeof(t), &t, TCA_GATE_PAD))
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goto nla_put_failure;
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spin_unlock_bh(&gact->tcf_lock);
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rcu_read_unlock();
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return skb->len;
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nla_put_failure:
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spin_unlock_bh(&gact->tcf_lock);
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rcu_read_unlock();
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nlmsg_trim(skb, b);
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return -1;
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}
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