act_ife: move tcfa_lock down to where necessary

The only time we need to take tcfa_lock is when adding
a new metainfo to an existing ife->metalist. We don't need
to take tcfa_lock so early and so br

act_ife: move tcfa_lock down to where necessary

The only time we need to take tcfa_lock is when adding
a new metainfo to an existing ife->metalist. We don't need
to take tcfa_lock so early and so broadly in tcf_ife_init().

This means we can always take ife_mod_lock first, avoid the
reverse locking ordering warning as reported by Vlad.

Reported-by: Vlad Buslov <vladbu@mellanox.com>
Tested-by: Vlad Buslov <vladbu@mellanox.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

Revert "net: sched: act_ife: disable bh when taking ife_mod_lock"

This reverts commit 42c625a486f3 ("net: sched: act_ife: disable bh
when taking ife_mod_lock"), because what ife_mod_lock protects
is

Revert "net: sched: act_ife: disable bh when taking ife_mod_lock"

This reverts commit 42c625a486f3 ("net: sched: act_ife: disable bh
when taking ife_mod_lock"), because what ife_mod_lock protects
is absolutely not touched in rate est timer BH context, they have
no race.

A better fix is following up.

Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net_sched: remove unnecessary ops->delete()

All ops->delete() wants is getting the tn->idrinfo, but we already
have tc_action before calling ops->delete(), and tc_action has
a pointer ->idrinfo.

Mo

net_sched: remove unnecessary ops->delete()

All ops->delete() wants is getting the tn->idrinfo, but we already
have tc_action before calling ops->delete(), and tc_action has
a pointer ->idrinfo.

More importantly, each type of action does the same thing, that is,
just calling tcf_idr_delete_index().

So it can be just removed.

Fixes: b409074e6693 ("net: sched: add 'delete' function to action ops")
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sched: act_ife: always release ife action on init error

Action init API was changed to always take reference to action, even when
overwriting existing action. Substitute conditional action rele

net: sched: act_ife: always release ife action on init error

Action init API was changed to always take reference to action, even when
overwriting existing action. Substitute conditional action release, which
was executed only if action is newly created, with unconditional release in
tcf_ife_init() error handling code to prevent double free or memory leak in
case of overwrite.

Fixes: 4e8ddd7f1758 ("net: sched: don't release reference on action overwrite")
Reported-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sched: act_ife: disable bh when taking ife_mod_lock

Lockdep reports deadlock for following locking scenario in ife action:

Task one:
1) Executes ife action update.
2) Takes tcfa_lock.
3) Waits

net: sched: act_ife: disable bh when taking ife_mod_lock

Lockdep reports deadlock for following locking scenario in ife action:

Task one:
1) Executes ife action update.
2) Takes tcfa_lock.
3) Waits on ife_mod_lock which is already taken by task two.

Task two:

1) Executes any path that obtains ife_mod_lock without disabling bh (any
path that takes ife_mod_lock while holding tcfa_lock has bh disabled) like
loading a meta module, or creating new action.
2) Takes ife_mod_lock.
3) Task is preempted by rate estimator timer.
4) Timer callback waits on tcfa_lock which is taken by task one.

In described case tasks deadlock because they take same two locks in
different order. To prevent potential deadlock reported by lockdep, always
disable bh when obtaining ife_mod_lock.

Lockdep warning:

[ 508.101192] =====================================================
[ 508.107708] WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
[ 508.114728] 4.18.0-rc8+ #646 Not tainted
[ 508.119050] -----------------------------------------------------
[ 508.125559] tc/5460 [HC0[0]:SC0[2]:HE1:SE0] is trying to acquire:
[ 508.132025] 000000005a938c68 (ife_mod_lock){++++}, at: find_ife_oplist+0x1e/0xc0 [act_ife]
[ 508.140996]
and this task is already holding:
[ 508.147548] 00000000d46f6c56 (&(&p->tcfa_lock)->rlock){+.-.}, at: tcf_ife_init+0x6ae/0xf40 [act_ife]
[ 508.157371] which would create a new lock dependency:
[ 508.162828] (&(&p->tcfa_lock)->rlock){+.-.} -> (ife_mod_lock){++++}
[ 508.169572]
but this new dependency connects a SOFTIRQ-irq-safe lock:
[ 508.178197] (&(&p->tcfa_lock)->rlock){+.-.}
[ 508.178201]
... which became SOFTIRQ-irq-safe at:
[ 508.189771] _raw_spin_lock+0x2c/0x40
[ 508.193906] est_fetch_counters+0x41/0xb0
[ 508.198391] est_timer+0x83/0x3c0
[ 508.202180] call_timer_fn+0x16a/0x5d0
[ 508.206400] run_timer_softirq+0x399/0x920
[ 508.210967] __do_softirq+0x157/0x97d
[ 508.215102] irq_exit+0x152/0x1c0
[ 508.218888] smp_apic_timer_interrupt+0xc0/0x4e0
[ 508.223976] apic_timer_interrupt+0xf/0x20
[ 508.228540] cpuidle_enter_state+0xf8/0x5d0
[ 508.233198] do_idle+0x28a/0x350
[ 508.236881] cpu_startup_entry+0xc7/0xe0
[ 508.241296] start_secondary+0x2e8/0x3f0
[ 508.245678] secondary_startup_64+0xa5/0xb0
[ 508.250347]
to a SOFTIRQ-irq-unsafe lock: (ife_mod_lock){++++}
[ 508.256531]
... which became SOFTIRQ-irq-unsafe at:
[ 508.267279] ...
[ 508.267283] _raw_write_lock+0x2c/0x40
[ 508.273653] register_ife_op+0x118/0x2c0 [act_ife]
[ 508.278926] do_one_initcall+0xf7/0x4d9
[ 508.283214] do_init_module+0x18b/0x44e
[ 508.287521] load_module+0x4167/0x5730
[ 508.291739] __do_sys_finit_module+0x16d/0x1a0
[ 508.296654] do_syscall_64+0x7a/0x3f0
[ 508.300788] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 508.306302]
other info that might help us debug this:

[ 508.315286] Possible interrupt unsafe locking scenario:

[ 508.322771] CPU0 CPU1
[ 508.327681] ---- ----
[ 508.332604] lock(ife_mod_lock);
[ 508.336300] local_irq_disable();
[ 508.342608] lock(&(&p->tcfa_lock)->rlock);
[ 508.349793] lock(ife_mod_lock);
[ 508.355990] <Interrupt>
[ 508.358974] lock(&(&p->tcfa_lock)->rlock);
[ 508.363803]
*** DEADLOCK ***

[ 508.370715] 2 locks held by tc/5460:
[ 508.374680] #0: 00000000e27e4fa4 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x583/0x7b0
[ 508.383366] #1: 00000000d46f6c56 (&(&p->tcfa_lock)->rlock){+.-.}, at: tcf_ife_init+0x6ae/0xf40 [act_ife]
[ 508.393648]
the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
[ 508.403505] -> (&(&p->tcfa_lock)->rlock){+.-.} ops: 1001553 {
[ 508.409646] HARDIRQ-ON-W at:
[ 508.413136] _raw_spin_lock_bh+0x34/0x40
[ 508.419059] gnet_stats_start_copy_compat+0xa2/0x230
[ 508.426021] gnet_stats_start_copy+0x16/0x20
[ 508.432333] tcf_action_copy_stats+0x95/0x1d0
[ 508.438735] tcf_action_dump_1+0xb0/0x4e0
[ 508.444795] tcf_action_dump+0xca/0x200
[ 508.450673] tcf_exts_dump+0xd9/0x320
[ 508.456392] fl_dump+0x1b7/0x4a0 [cls_flower]
[ 508.462798] tcf_fill_node+0x380/0x530
[ 508.468601] tfilter_notify+0xdf/0x1c0
[ 508.474404] tc_new_tfilter+0x84a/0xc90
[ 508.480270] rtnetlink_rcv_msg+0x5bd/0x7b0
[ 508.486419] netlink_rcv_skb+0x184/0x220
[ 508.492394] netlink_unicast+0x31b/0x460
[ 508.507411] netlink_sendmsg+0x3fb/0x840
[ 508.513390] sock_sendmsg+0x7b/0xd0
[ 508.518907] ___sys_sendmsg+0x4c6/0x610
[ 508.524797] __sys_sendmsg+0xd7/0x150
[ 508.530510] do_syscall_64+0x7a/0x3f0
[ 508.536201] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 508.543301] IN-SOFTIRQ-W at:
[ 508.546834] _raw_spin_lock+0x2c/0x40
[ 508.552522] est_fetch_counters+0x41/0xb0
[ 508.558571] est_timer+0x83/0x3c0
[ 508.563912] call_timer_fn+0x16a/0x5d0
[ 508.569699] run_timer_softirq+0x399/0x920
[ 508.575840] __do_softirq+0x157/0x97d
[ 508.581538] irq_exit+0x152/0x1c0
[ 508.586882] smp_apic_timer_interrupt+0xc0/0x4e0
[ 508.593533] apic_timer_interrupt+0xf/0x20
[ 508.599686] cpuidle_enter_state+0xf8/0x5d0
[ 508.605895] do_idle+0x28a/0x350
[ 508.611147] cpu_startup_entry+0xc7/0xe0
[ 508.617097] start_secondary+0x2e8/0x3f0
[ 508.623029] secondary_startup_64+0xa5/0xb0
[ 508.629245] INITIAL USE at:
[ 508.632686] _raw_spin_lock_bh+0x34/0x40
[ 508.638557] gnet_stats_start_copy_compat+0xa2/0x230
[ 508.645491] gnet_stats_start_copy+0x16/0x20
[ 508.651719] tcf_action_copy_stats+0x95/0x1d0
[ 508.657992] tcf_action_dump_1+0xb0/0x4e0
[ 508.663937] tcf_action_dump+0xca/0x200
[ 508.669716] tcf_exts_dump+0xd9/0x320
[ 508.675337] fl_dump+0x1b7/0x4a0 [cls_flower]
[ 508.681650] tcf_fill_node+0x380/0x530
[ 508.687366] tfilter_notify+0xdf/0x1c0
[ 508.693031] tc_new_tfilter+0x84a/0xc90
[ 508.698820] rtnetlink_rcv_msg+0x5bd/0x7b0
[ 508.704869] netlink_rcv_skb+0x184/0x220
[ 508.710758] netlink_unicast+0x31b/0x460
[ 508.716627] netlink_sendmsg+0x3fb/0x840
[ 508.722510] sock_sendmsg+0x7b/0xd0
[ 508.727931] ___sys_sendmsg+0x4c6/0x610
[ 508.733729] __sys_sendmsg+0xd7/0x150
[ 508.739346] do_syscall_64 +0x7a/0x3f0
[ 508.744943] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 508.751930] }
[ 508.753964] ... key at: [<ffffffff916b3e20>] __key.61145+0x0/0x40
[ 508.760946] ... acquired at:
[ 508.764294] _raw_read_lock+0x2f/0x40
[ 508.768513] find_ife_oplist+0x1e/0xc0 [act_ife]
[ 508.773692] tcf_ife_init+0x82f/0xf40 [act_ife]
[ 508.778785] tcf_action_init_1+0x510/0x750
[ 508.783468] tcf_action_init+0x1e8/0x340
[ 508.787938] tcf_action_add+0xc5/0x240
[ 508.792241] tc_ctl_action+0x203/0x2a0
[ 508.796550] rtnetlink_rcv_msg+0x5bd/0x7b0
[ 508.801200] netlink_rcv_skb+0x184/0x220
[ 508.805674] netlink_unicast+0x31b/0x460
[ 508.810129] netlink_sendmsg+0x3fb/0x840
[ 508.814611] sock_sendmsg+0x7b/0xd0
[ 508.818665] ___sys_sendmsg+0x4c6/0x610
[ 508.823029] __sys_sendmsg+0xd7/0x150
[ 508.827246] do_syscall_64+0x7a/0x3f0
[ 508.831483] entry_SYSCALL_64_after_hwframe+0x49/0xbe

the dependencies between the lock to be acquired
[ 508.838945] and SOFTIRQ-irq-unsafe lock:
[ 508.851177] -> (ife_mod_lock){++++} ops: 95 {
[ 508.855920] HARDIRQ-ON-W at:
[ 508.859478] _raw_write_lock+0x2c/0x40
[ 508.865264] register_ife_op+0x118/0x2c0 [act_ife]
[ 508.872071] do_one_initcall+0xf7/0x4d9
[ 508.877947] do_init_module+0x18b/0x44e
[ 508.883819] load_module+0x4167/0x5730
[ 508.889595] __do_sys_finit_module+0x16d/0x1a0
[ 508.896043] do_syscall_64+0x7a/0x3f0
[ 508.901734] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 508.908827] HARDIRQ-ON-R at:
[ 508.912359] _raw_read_lock+0x2f/0x40
[ 508.918043] find_ife_oplist+0x1e/0xc0 [act_ife]
[ 508.924692] tcf_ife_init+0x82f/0xf40 [act_ife]
[ 508.931252] tcf_action_init_1+0x510/0x750
[ 508.937393] tcf_action_init+0x1e8/0x340
[ 508.943366] tcf_action_add+0xc5/0x240
[ 508.949130] tc_ctl_action+0x203/0x2a0
[ 508.954922] rtnetlink_rcv_msg+0x5bd/0x7b0
[ 508.961024] netlink_rcv_skb+0x184/0x220
[ 508.966970] netlink_unicast+0x31b/0x460
[ 508.972915] netlink_sendmsg+0x3fb/0x840
[ 508.978859] sock_sendmsg+0x7b/0xd0
[ 508.984400] ___sys_sendmsg+0x4c6/0x610
[ 508.990264] __sys_sendmsg+0xd7/0x150
[ 508.995952] do_syscall_64+0x7a/0x3f0
[ 509.001643] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 509.008722] SOFTIRQ-ON-W at:\
[ 509.012242] _raw_write_lock+0x2c/0x40
[ 509.018013] register_ife_op+0x118/0x2c0 [act_ife]
[ 509.024841] do_one_initcall+0xf7/0x4d9
[ 509.030720] do_init_module+0x18b/0x44e
[ 509.036604] load_module+0x4167/0x5730
[ 509.042397] __do_sys_finit_module+0x16d/0x1a0
[ 509.048865] do_syscall_64+0x7a/0x3f0
[ 509.054551] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 509.061636] SOFTIRQ-ON-R at:
[ 509.065145] _raw_read_lock+0x2f/0x40
[ 509.070854] find_ife_oplist+0x1e/0xc0 [act_ife]
[ 509.077515] tcf_ife_init+0x82f/0xf40 [act_ife]
[ 509.084051] tcf_action_init_1+0x510/0x750
[ 509.090172] tcf_action_init+0x1e8/0x340
[ 509.096124] tcf_action_add+0xc5/0x240
[ 509.101891] tc_ctl_action+0x203/0x2a0
[ 509.107671] rtnetlink_rcv_msg+0x5bd/0x7b0
[ 509.113811] netlink_rcv_skb+0x184/0x220
[ 509.119768] netlink_unicast+0x31b/0x460
[ 509.125716] netlink_sendmsg+0x3fb/0x840
[ 509.131668] sock_sendmsg+0x7b/0xd0
[ 509.137167] ___sys_sendmsg+0x4c6/0x610
[ 509.143010] __sys_sendmsg+0xd7/0x150
[ 509.148718] do_syscall_64+0x7a/0x3f0
[ 509.154443] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 509.161533] INITIAL USE at:
[ 509.164956] _raw_read_lock+0x2f/0x40
[ 509.170574] find_ife_oplist+0x1e/0xc0 [act_ife]
[ 509.177134] tcf_ife_init+0x82f/0xf40 [act_ife]
[ 509.183619] tcf_action_init_1+0x510/0x750
[ 509.189674] tcf_action_init+0x1e8/0x340
[ 509.195534] tcf_action_add+0xc5/0x240
[ 509.201229] tc_ctl_action+0x203/0x2a0
[ 509.206920] rtnetlink_rcv_msg+0x5bd/0x7b0
[ 509.212936] netlink_rcv_skb+0x184/0x220
[ 509.218818] netlink_unicast+0x31b/0x460
[ 509.224699] netlink_sendmsg+0x3fb/0x840
[ 509.230581] sock_sendmsg+0x7b/0xd0
[ 509.235984] ___sys_sendmsg+0x4c6/0x610
[ 509.241791] __sys_sendmsg+0xd7/0x150
[ 509.247425] do_syscall_64+0x7a/0x3f0
[ 509.253007] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 509.259975] }
[ 509.261998] ... key at: [<ffffffffc1554258>] ife_mod_lock+0x18/0xffffffffffff8dc0 [act_ife]
[ 509.271569] ... acquired at:
[ 509.274912] _raw_read_lock+0x2f/0x40
[ 509.279134] find_ife_oplist+0x1e/0xc0 [act_ife]
[ 509.284324] tcf_ife_init+0x82f/0xf40 [act_ife]
[ 509.289425] tcf_action_init_1+0x510/0x750
[ 509.294068] tcf_action_init+0x1e8/0x340
[ 509.298553] tcf_action_add+0xc5/0x240
[ 509.302854] tc_ctl_action+0x203/0x2a0
[ 509.307153] rtnetlink_rcv_msg+0x5bd/0x7b0
[ 509.311805] netlink_rcv_skb+0x184/0x220
[ 509.316282] netlink_unicast+0x31b/0x460
[ 509.320769] netlink_sendmsg+0x3fb/0x840
[ 509.325248] sock_sendmsg+0x7b/0xd0
[ 509.329290] ___sys_sendmsg+0x4c6/0x610
[ 509.333687] __sys_sendmsg+0xd7/0x150
[ 509.337902] do_syscall_64+0x7a/0x3f0
[ 509.342116] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 509.349601]
stack backtrace:
[ 509.354663] CPU: 6 PID: 5460 Comm: tc Not tainted 4.18.0-rc8+ #646
[ 509.361216] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017

Fixes: ef6980b6becb ("introduce IFE action")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sched: act_ife: remove dependency on rtnl lock

Use tcf spinlock and rcu to protect params pointer from concurrent
modification during dump and init. Use rcu swap operation to reassign
params po

net: sched: act_ife: remove dependency on rtnl lock

Use tcf spinlock and rcu to protect params pointer from concurrent
modification during dump and init. Use rcu swap operation to reassign
params pointer under protection of tcf lock. (old params value is not used
by init, so there is no need of standalone rcu dereference step)

Ife action has meta-actions that are compiled as standalone modules. Rtnl
mutex must be released while loading a kernel module. In order to support
execution without rtnl mutex, propagate 'rtnl_held' argument to meta action
loading functions. When requesting meta action module, conditionally
release rtnl lock depending on 'rtnl_held' argument.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

tc/act: remove unneeded RCU lock in action callback

Each lockless action currently does its own RCU locking in ->act().
This allows using plain RCU accessor, even if the context
is really RCU BH.

T

tc/act: remove unneeded RCU lock in action callback

Each lockless action currently does its own RCU locking in ->act().
This allows using plain RCU accessor, even if the context
is really RCU BH.

This change drops the per action RCU lock, replace the accessors
with the _bh variant, cleans up a bit the surrounding code and
documents the RCU status in the relevant header.
No functional nor performance change is intended.

The goal of this patch is clarifying that the RCU critical section
used by the tc actions extends up to the classifier's caller.

v1 -> v2:
- preserve rcu lock in act_bpf: it's needed by eBPF helpers,
as pointed out by Daniel

v3 -> v4:
- fixed some typos in the commit message (JiriP)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sched: act_ife: fix memory leak in ife init

Free params if tcf_idr_check_alloc() returned error.

Fixes: 0190c1d452a9 ("net: sched: atomically check-allocate action")
Reported-by: Dan Carpenter

net: sched: act_ife: fix memory leak in ife init

Free params if tcf_idr_check_alloc() returned error.

Fixes: 0190c1d452a9 ("net: sched: atomically check-allocate action")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sched: atomically check-allocate action

Implement function that atomically checks if action exists and either takes
reference to it, or allocates idr slot for action index to prevent
concurrent

net: sched: atomically check-allocate action

Implement function that atomically checks if action exists and either takes
reference to it, or allocates idr slot for action index to prevent
concurrent allocations of actions with same index. Use EBUSY error pointer
to indicate that idr slot is reserved.

Implement cleanup helper function that removes temporary error pointer from
idr. (in case of error between idr allocation and insertion of newly
created action to specified index)

Refactor all action init functions to insert new action to idr using this
API.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sched: don't release reference on action overwrite

Return from action init function with reference to action taken,
even when overwriting existing action.

Action init API initializes its fourt

net: sched: don't release reference on action overwrite

Return from action init function with reference to action taken,
even when overwriting existing action.

Action init API initializes its fourth argument (pointer to pointer to tc
action) to either existing action with same index or newly created action.
In case of existing index(and bind argument is zero), init function returns
without incrementing action reference counter. Caller of action init then
proceeds working with action, without actually holding reference to it.
This means that action could be deleted concurrently.

Change action init behavior to always take reference to action before
returning successfully, in order to protect from concurrent deletion.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: sched: add 'delete' function to action ops

Extend action ops with 'delete' function. Each action type to implements
its own delete function that doesn't depend on rtnl lock.

Implement delete f

net: sched: add 'delete' function to action ops

Extend action ops with 'delete' function. Each action type to implements
its own delete function that doesn't depend on rtnl lock.

Implement delete function that is required to delete actions without
holding rtnl lock. Use action API function that atomically deletes action
only if it is still in action idr. This implementation prevents concurrent
threads from deleting same action twice.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: sched: implement unlocked action init API

Add additional 'rtnl_held' argument to act API init functions. It is
required to implement actions that need to release rtnl lock before loading
kernel

net: sched: implement unlocked action init API

Add additional 'rtnl_held' argument to act API init functions. It is
required to implement actions that need to release rtnl lock before loading
kernel module and reacquire if afterwards.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: sched: change type of reference and bind counters

Change type of action reference counter to refcount_t.

Change type of action bind counter to atomic_t.
This type is used to allow decrementing

net: sched: change type of reference and bind counters

Change type of action reference counter to refcount_t.

Change type of action bind counter to atomic_t.
This type is used to allow decrementing bind counter without testing
for 0 result.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net/sched: act_ife: preserve the action control in case of error

in the following script

# tc actions add action ife encode allow prio pass index 42
# tc actions replace action ife encode allow t

net/sched: act_ife: preserve the action control in case of error

in the following script

# tc actions add action ife encode allow prio pass index 42
# tc actions replace action ife encode allow tcindex drop index 42

the action control should remain equal to 'pass', if the kernel failed
to replace the TC action. Pospone the assignment of the action control,
to ensure it is not overwritten in the error path of tcf_ife_init().

Fixes: ef6980b6becb ("introduce IFE action")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net/sched: act_ife: fix recursive lock and idr leak

a recursive lock warning [1] can be observed with the following script,

# $TC actions add action ife encode allow prio pass index 42
IFE type 0

net/sched: act_ife: fix recursive lock and idr leak

a recursive lock warning [1] can be observed with the following script,

# $TC actions add action ife encode allow prio pass index 42
IFE type 0xED3E
# $TC actions replace action ife encode allow tcindex pass index 42

in case the kernel was unable to run the last command (e.g. because of
the impossibility to load 'act_meta_skbtcindex'). For a similar reason,
the kernel can leak idr in the error path of tcf_ife_init(), because
tcf_idr_release() is not called after successful idr reservation:

# $TC actions add action ife encode allow tcindex index 47
IFE type 0xED3E
RTNETLINK answers: No such file or directory
We have an error talking to the kernel
# $TC actions add action ife encode allow tcindex index 47
IFE type 0xED3E
RTNETLINK answers: No space left on device
We have an error talking to the kernel
# $TC actions add action ife encode use mark 7 type 0xfefe pass index 47
IFE type 0xFEFE
RTNETLINK answers: No space left on device
We have an error talking to the kernel

Since tcfa_lock is already taken when the action is being edited, a call
to tcf_idr_release() wrongly makes tcf_idr_cleanup() take the same lock
again. On the other hand, tcf_idr_release() needs to be called in the
error path of tcf_ife_init(), to undo the last tcf_idr_create() invocation.
Fix both problems in tcf_ife_init().
Since the cleanup() routine can now be called when ife->params is NULL,
also add a NULL pointer check to avoid calling kfree_rcu(NULL, rcu).

[1]
============================================
WARNING: possible recursive locking detected
4.17.0-rc4.kasan+ #417 Tainted: G E
--------------------------------------------
tc/3932 is trying to acquire lock:
000000005097c9a6 (&(&p->tcfa_lock)->rlock){+...}, at: tcf_ife_cleanup+0x19/0x80 [act_ife]

but task is already holding lock:
000000005097c9a6 (&(&p->tcfa_lock)->rlock){+...}, at: tcf_ife_init+0xf6d/0x13c0 [act_ife]

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&(&p->tcfa_lock)->rlock);
lock(&(&p->tcfa_lock)->rlock);

*** DEADLOCK ***

May be due to missing lock nesting notation

2 locks held by tc/3932:
#0: 000000007ca8e990 (rtnl_mutex){+.+.}, at: tcf_ife_init+0xf61/0x13c0 [act_ife]
#1: 000000005097c9a6 (&(&p->tcfa_lock)->rlock){+...}, at: tcf_ife_init+0xf6d/0x13c0 [act_ife]

stack backtrace:
CPU: 3 PID: 3932 Comm: tc Tainted: G E 4.17.0-rc4.kasan+ #417
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Call Trace:
dump_stack+0x9a/0xeb
__lock_acquire+0xf43/0x34a0
? debug_check_no_locks_freed+0x2b0/0x2b0
? debug_check_no_locks_freed+0x2b0/0x2b0
? debug_check_no_locks_freed+0x2b0/0x2b0
? __mutex_lock+0x62f/0x1240
? kvm_sched_clock_read+0x1a/0x30
? sched_clock+0x5/0x10
? sched_clock_cpu+0x18/0x170
? find_held_lock+0x39/0x1d0
? lock_acquire+0x10b/0x330
lock_acquire+0x10b/0x330
? tcf_ife_cleanup+0x19/0x80 [act_ife]
_raw_spin_lock_bh+0x38/0x70
? tcf_ife_cleanup+0x19/0x80 [act_ife]
tcf_ife_cleanup+0x19/0x80 [act_ife]
__tcf_idr_release+0xff/0x350
tcf_ife_init+0xdde/0x13c0 [act_ife]
? ife_exit_net+0x290/0x290 [act_ife]
? __lock_is_held+0xb4/0x140
tcf_action_init_1+0x67b/0xad0
? tcf_action_dump_old+0xa0/0xa0
? sched_clock+0x5/0x10
? sched_clock_cpu+0x18/0x170
? kvm_sched_clock_read+0x1a/0x30
? sched_clock+0x5/0x10
? sched_clock_cpu+0x18/0x170
? memset+0x1f/0x40
tcf_action_init+0x30f/0x590
? tcf_action_init_1+0xad0/0xad0
? memset+0x1f/0x40
tc_ctl_action+0x48e/0x5e0
? mutex_lock_io_nested+0x1160/0x1160
? tca_action_gd+0x990/0x990
? sched_clock+0x5/0x10
? find_held_lock+0x39/0x1d0
rtnetlink_rcv_msg+0x4da/0x990
? validate_linkmsg+0x680/0x680
? sched_clock_cpu+0x18/0x170
? find_held_lock+0x39/0x1d0
netlink_rcv_skb+0x127/0x350
? validate_linkmsg+0x680/0x680
? netlink_ack+0x970/0x970
? __kmalloc_node_track_caller+0x304/0x3a0
netlink_unicast+0x40f/0x5d0
? netlink_attachskb+0x580/0x580
? _copy_from_iter_full+0x187/0x760
? import_iovec+0x90/0x390
netlink_sendmsg+0x67f/0xb50
? netlink_unicast+0x5d0/0x5d0
? copy_msghdr_from_user+0x206/0x340
? netlink_unicast+0x5d0/0x5d0
sock_sendmsg+0xb3/0xf0
___sys_sendmsg+0x60a/0x8b0
? copy_msghdr_from_user+0x340/0x340
? lock_downgrade+0x5e0/0x5e0
? tty_write_lock+0x18/0x50
? kvm_sched_clock_read+0x1a/0x30
? sched_clock+0x5/0x10
? sched_clock_cpu+0x18/0x170
? find_held_lock+0x39/0x1d0
? lock_downgrade+0x5e0/0x5e0
? lock_acquire+0x10b/0x330
? __audit_syscall_entry+0x316/0x690
? current_kernel_time64+0x6b/0xd0
? __fget_light+0x55/0x1f0
? __sys_sendmsg+0xd2/0x170
__sys_sendmsg+0xd2/0x170
? __ia32_sys_shutdown+0x70/0x70
? syscall_trace_enter+0x57a/0xd60
? rcu_read_lock_sched_held+0xdc/0x110
? __bpf_trace_sys_enter+0x10/0x10
? do_syscall_64+0x22/0x480
do_syscall_64+0xa5/0x480
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fd646988ba0
RSP: 002b:00007fffc9fab3c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fffc9fab4f0 RCX: 00007fd646988ba0
RDX: 0000000000000000 RSI: 00007fffc9fab440 RDI: 0000000000000003
RBP: 000000005b28c8b3 R08: 0000000000000002 R09: 0000000000000000
R10: 00007fffc9faae20 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffc9fab504 R14: 0000000000000001 R15: 000000000066c100

Fixes: 4e8c86155010 ("net sched: net sched: ife action fix late binding")
Fixes: ef6980b6becb ("introduce IFE action")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sched: ife: handle malformed tlv length

There is currently no handling to check on a invalid tlv length. This
patch adds such handling to avoid killing the kernel with a malformed
ife packet.

net: sched: ife: handle malformed tlv length

There is currently no handling to check on a invalid tlv length. This
patch adds such handling to avoid killing the kernel with a malformed
ife packet.

Signed-off-by: Alexander Aring <aring@mojatatu.com>
Reviewed-by: Yotam Gigi <yotam.gi@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: sched: ife: signal not finding metaid

We need to record stats for received metadata that we dont know how
to process. Have find_decode_metaid() return -ENOENT to capture this.

Signed-off-by: A

net: sched: ife: signal not finding metaid

We need to record stats for received metadata that we dont know how
to process. Have find_decode_metaid() return -ENOENT to capture this.

Signed-off-by: Alexander Aring <aring@mojatatu.com>
Reviewed-by: Yotam Gigi <yotam.gi@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: Drop pernet_operations::async

Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Sig

net: Drop pernet_operations::async

Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: Convert tc_action_net_init() and tc_action_net_exit() based pernet_operations

These pernet_operations are from net/sched directory, and they call only
tc_action_net_init() and tc_action_net_exi

net: Convert tc_action_net_init() and tc_action_net_exit() based pernet_operations

These pernet_operations are from net/sched directory, and they call only
tc_action_net_init() and tc_action_net_exit():

bpf_net_ops
connmark_net_ops
csum_net_ops
gact_net_ops
ife_net_ops
ipt_net_ops
xt_net_ops
mirred_net_ops
nat_net_ops
pedit_net_ops
police_net_ops
sample_net_ops
simp_net_ops
skbedit_net_ops
skbmod_net_ops
tunnel_key_net_ops
vlan_net_ops

1)tc_action_net_init() just allocates and initializes per-net memory.
2)There should not be in-flight packets at the time of tc_action_net_exit()
call, or another pernet_operations send packets to dying net (except
netlink). So, it seems they can be marked as async.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: sched: act: handle extack in tcf_generic_walker

This patch adds extack handling for a common used TC act function
"tcf_generic_walker()" to add an extack message on failures.
The tcf_generic_wa

net: sched: act: handle extack in tcf_generic_walker

This patch adds extack handling for a common used TC act function
"tcf_generic_walker()" to add an extack message on failures.
The tcf_generic_walker() function can fail if get a invalid command
different than DEL and GET. The naming "action" here is wrong, the
correct naming would be command.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: sched: act: add extack for walk callback

This patch adds extack support for act walker callback api. This
prepares to handle extack support inside each specific act
implementation.

Cc: David A

net: sched: act: add extack for walk callback

This patch adds extack support for act walker callback api. This
prepares to handle extack support inside each specific act
implementation.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: sched: act: add extack for lookup callback

This patch adds extack support for act lookup callback api. This
prepares to handle extack support inside each specific act
implementation.

Cc: David

net: sched: act: add extack for lookup callback

This patch adds extack support for act lookup callback api. This
prepares to handle extack support inside each specific act
implementation.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: sched: act: add extack to init callback

This patch adds extack support for act init callback api. This
prepares to handle extack support inside each specific act
implementation.

Based on work

net: sched: act: add extack to init callback

This patch adds extack support for act init callback api. This
prepares to handle extack support inside each specific act
implementation.

Based on work by David Ahern <dsahern@gmail.com>

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net_sched: switch to exit_batch for action pernet ops

Since we now hold RTNL lock in tc_action_net_exit(), it is good to
batch them to speedup tc action dismantle.

Cc: Jamal Hadi Salim <jhs@mojatat

net_sched: switch to exit_batch for action pernet ops

Since we now hold RTNL lock in tc_action_net_exit(), it is good to
batch them to speedup tc action dismantle.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net_sched: remove unused parameter from act cleanup ops

No one actually uses it.

Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@

net_sched: remove unused parameter from act cleanup ops

No one actually uses it.

Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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