Commit Graph

61 Commits

Author SHA1 Message Date
Cong Wang 5ffe57da29 act_ife: fix a potential deadlock
use_all_metadata() acquires read_lock(&ife_mod_lock), then calls
add_metainfo() which calls find_ife_oplist() which acquires the same
lock again. Deadlock!

Introduce __add_metainfo() which accepts struct tcf_meta_ops *ops
as an additional parameter and let its callers to decide how
to find it. For use_all_metadata(), it already has ops, no
need to find it again, just call __add_metainfo() directly.

And, as ife_mod_lock is only needed for find_ife_oplist(),
this means we can make non-atomic allocation for populate_metalist()
now.

Fixes: 817e9f2c5c ("act_ife: acquire ife_mod_lock before reading ifeoplist")
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>
2018-08-21 12:45:45 -07:00
Cong Wang 4e407ff5cd 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>
2018-08-21 12:45:45 -07:00
Cong Wang 8ce5be1c89 Revert "net: sched: act_ife: disable bh when taking ife_mod_lock"
This reverts commit 42c625a486 ("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>
2018-08-21 12:45:45 -07:00
Cong Wang 97a3f84f2c 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: b409074e66 ("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>
2018-08-21 12:45:44 -07:00
Vlad Buslov 32039eac4c 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: 4e8ddd7f17 ("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>
2018-08-16 12:12:12 -07:00
Vlad Buslov 42c625a486 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: ef6980b6be ("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>
2018-08-13 11:45:06 -07:00
Vlad Buslov 54d0d423a4 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>
2018-08-11 12:37:09 -07:00
Paolo Abeni 7fd4b288ea 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>
2018-07-30 09:31:13 -07:00
Vlad Buslov 01e866bf07 net: sched: act_ife: fix memory leak in ife init
Free params if tcf_idr_check_alloc() returned error.

Fixes: 0190c1d452 ("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>
2018-07-11 22:53:00 -07:00
Vlad Buslov 0190c1d452 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>
2018-07-08 12:42:29 +09:00
Vlad Buslov 4e8ddd7f17 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>
2018-07-08 12:42:29 +09:00
Vlad Buslov b409074e66 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>
2018-07-08 12:42:29 +09:00
Vlad Buslov 789871bb2a 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>
2018-07-08 12:42:28 +09:00
Vlad Buslov 036bb44327 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>
2018-07-08 12:42:28 +09:00
Davide Caratti cbf56c2962 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: ef6980b6be ("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>
2018-06-20 09:03:58 +09:00
Davide Caratti 0a889b9404 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: 4e8c861550 ("net sched: net sched: ife action fix late binding")
Fixes: ef6980b6be ("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>
2018-06-20 09:03:58 +09:00
Alexander Aring cc74eddd0f 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>
2018-04-22 21:12:00 -04:00
Alexander Aring f6cd14537f 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>
2018-04-22 21:12:00 -04:00
Kirill Tkhai 2f635ceeb2 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>
2018-03-27 13:18:09 -04:00
Kirill Tkhai 685ecfb198 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>
2018-02-27 11:01:36 -05:00
Alexander Aring b36201455a 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>
2018-02-16 16:05:50 -05:00
Alexander Aring 417801055b 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>
2018-02-16 16:05:50 -05:00
Alexander Aring 331a9295de 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>
2018-02-16 16:05:03 -05:00
Alexander Aring 589dad6d71 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>
2018-02-16 16:05:03 -05:00
Cong Wang 039af9c66b 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>
2017-12-13 13:58:41 -05:00
Cong Wang 9a63b255df 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>
2017-12-05 18:07:58 -05:00
David S. Miller 4dc6758d78 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Simple cases of overlapping changes in the packet scheduler.

Must easier to resolve this time.

Which probably means that I screwed it up somehow.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-10 10:00:18 +09:00
Cong Wang c7e460ce55 Revert "net_sched: hold netns refcnt for each action"
This reverts commit ceffcc5e25.
If we hold that refcnt, the netns can never be destroyed until
all actions are destroyed by user, this breaks our netns design
which we expect all actions are destroyed when we destroy the
whole netns.

Cc: Lucas Bates <lucasb@mojatatu.com>
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>
2017-11-09 10:03:09 +09:00
David S. Miller 2a171788ba Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Files removed in 'net-next' had their license header updated
in 'net'.  We take the remove from 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-04 09:26:51 +09:00
Cong Wang ceffcc5e25 net_sched: hold netns refcnt for each action
TC actions have been destroyed asynchronously for a long time,
previously in a RCU callback and now in a workqueue. If we
don't hold a refcnt for its netns, we could use the per netns
data structure, struct tcf_idrinfo, after it has been freed by
netns workqueue.

Hold refcnt to ensure netns destroy happens after all actions
are gone.

Fixes: ddf97ccdd7 ("net_sched: add network namespace support for tc actions")
Reported-by: Lucas Bates <lucasb@mojatatu.com>
Tested-by: Lucas Bates <lucasb@mojatatu.com>
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>
2017-11-03 10:30:38 +09:00
Cong Wang 6578759447 net_sched: fix a compile warning in act_ife
Apparently ife_meta_id2name() is only called when
CONFIG_MODULES is defined.

This fixes:

net/sched/act_ife.c:251:20: warning: ‘ife_meta_id2name’ defined but not used [-Wunused-function]
 static const char *ife_meta_id2name(u32 metaid)
                    ^~~~~~~~~~~~~~~~

Fixes: d3f24ba895 ("net sched actions: fix module auto-loading")
Cc: Roman Mashak <mrv@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-14 18:43:45 -07:00
Alexander Aring aa9fd9a325 sched: act: ife: update parameters via rcu handling
This patch changes the parameter updating via RCU and not protected by a
spinlock anymore. This reduce the time that the spinlock is being held.

Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-12 22:23:03 -07:00
Alexander Aring ced273eacf sched: act: ife: migrate to use per-cpu counters
This patch migrates the current counter handling which is protected by a
spinlock to a per-cpu counter handling. This reduce the time where the
spinlock is being held.

Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-12 22:23:03 -07:00
Alexander Aring 734534e9a8 sched: act: ife: move encode/decode check to init
This patch adds the check of the two possible ife handlings encode
and decode to the init callback. The decode value is for usability
aspect and used in userspace code only. The current code offers encode
else decode only. This patch avoids any other option than this.

Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-12 22:23:02 -07:00
Roman Mashak d3f24ba895 net sched actions: fix module auto-loading
Macro __stringify_1() can stringify a macro argument, however IFE_META_*
are enums, so they never expand, however request_module expects an integer
in IFE module name, so as a result it always fails to auto-load.

Fixes: ef6980b6be ("introduce IFE action")
Signed-off-by: Roman Mashak <mrv@mojatatu.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-12 22:13:20 -07:00
Roman Mashak 8f04748016 net sched actions: change IFE modules alias names
Make style of module alias name consistent with other subsystems in kernel,
for example net devices.

Fixes: 084e2f6566 ("Support to encoding decoding skb mark on IFE action")
Fixes: 200e10f469 ("Support to encoding decoding skb prio on IFE action")
Fixes: 408fbc22ef ("net sched ife action: Introduce skb tcindex metadata encap decap")
Signed-off-by: Roman Mashak <mrv@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-12 22:13:20 -07:00
Chris Mi 65a206c01e net/sched: Change act_api and act_xxx modules to use IDR
Typically, each TC filter has its own action. All the actions of the
same type are saved in its hash table. But the hash buckets are too
small that it degrades to a list. And the performance is greatly
affected. For example, it takes about 0m11.914s to insert 64K rules.
If we convert the hash table to IDR, it only takes about 0m1.500s.
The improvement is huge.

But please note that the test result is based on previous patch that
cls_flower uses IDR.

Signed-off-by: Chris Mi <chrism@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-30 14:38:51 -07:00
Alexander Aring b522ed6ed6 act_ife: use registered ife_type as fallback
This patch handles a default IFE type if it's not given by user space
netlink api. The default IFE type will be the registered ethertype by
IEEE for IFE ForCES.

Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-29 15:14:18 -07:00
Johannes Berg fceb6435e8 netlink: pass extended ACK struct to parsing functions
Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13 13:58:22 -04:00
Or Gerlitz 4dba87b073 net/sched: act_ife: Staticfy find_decode_metaid()
As it's used only on that file.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-16 12:02:14 -07:00
Yotam Gigi 295a6e06d2 net/sched: act_ife: Change to use ife module
Use the encode/decode functionality from the ife module instead of using
implementation inside the act_ife.

Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Roman Mashak <mrv@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-03 15:16:46 -05:00
Yotam Gigi 1d5e7c859e net/sched: act_ife: Unexport ife_tlv_meta_encode
As the function ife_tlv_meta_encode is not used by any other module,
unexport it and make it static for the act_ife module.

Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Roman Mashak <mrv@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-03 15:16:45 -05:00
Willem de Bruijn a5135bcfba net-tc: convert tc_verd to integer bitfields
Extract the remaining two fields from tc_verd and remove the __u16
completely. TC_AT and TC_FROM are converted to equivalent two-bit
integer fields tc_at and tc_from. Where possible, use existing
helper skb_at_tc_ingress when reading tc_at. Introduce helper
skb_reset_tc to clear fields.

Not documenting tc_from and tc_at, because they will be replaced
with single bit fields in follow-on patches.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-08 20:58:52 -05:00
Alexey Dobriyan c7d03a00b5 netns: make struct pernet_operations::id unsigned int
Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng->ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-18 10:59:15 -05:00
David S. Miller b50afd203a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Three sets of overlapping changes.  Nothing serious.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-02 22:20:41 -04:00
Yotam Gigi c006da0be0 act_ife: Fix false encoding
On ife encode side, the action stores the different tlvs inside the ife
header, where each tlv length field should refer to the length of the
whole tlv (without additional padding) and not just the data length.

On ife decode side, the action iterates over the tlvs in the ife header
and parses them one by one, where in each iteration the current pointer is
advanced according to the tlv size.

Before, the encoding encoded only the data length inside the tlv, which led
to false parsing of ife the header. In addition, due to the fact that the
loop counter was unsigned, it could lead to infinite parsing loop.

This fix changes the loop counter to be signed and fixes the encoding to
take into account the tlv type and size.

Fixes: 28a10c426e ("net sched: fix encoding to use real length")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-27 09:53:17 -04:00
Yotam Gigi 4b1d488a28 act_ife: Fix external mac header on encode
On ife encode side, external mac header is copied from the original packet
and may be overridden if the user requests. Before, the mac header copy
was done from memory region that might not be accessible anymore, as
skb_cow_head might free it and copy the packet. This led to random values
in the external mac header once the values were not set by user.

This fix takes the internal mac header from the packet, after the call to
skb_cow_head.

Fixes: ef6980b6be ("net sched: introduce IFE action")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-27 09:53:16 -04:00
Jamal Hadi Salim 6a5d58b67e net sched ife action: add 16 bit helpers
encoder and checker for 16 bits metadata

Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-19 21:55:28 -04:00
Jamal Hadi Salim 28a10c426e net sched: fix encoding to use real length
Encoding of the metadata was using the padded length as opposed to
the real length of the data which is a bug per specification.
This has not been an issue todate because all metadatum specified
so far has been 32 bit where aligned and data length are the same width.
This also includes a bug fix for validating the length of a u16 field.
But since there is no metadata of size u16 yes we are fine to include it
here.

While at it get rid of magic numbers.

Fixes: ef6980b6be ("net sched: introduce IFE action")
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-22 21:01:57 -07:00
WANG Cong a85a970af2 net_sched: move tc_action into tcf_common
struct tc_action is confusing, currently we use it for two purposes:
1) Pass in arguments and carry out results from helper functions
2) A generic representation for tc actions

The first one is error-prone, since we need to make sure we don't
miss anything. This patch aims to get rid of this use, by moving
tc_action into tcf_common, so that they are allocated together
in hashtable and can be cast'ed easily.

And together with the following patch, we could really make
tc_action a generic representation for all tc actions and each
type of action can inherit from it.

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>
2016-07-25 21:49:19 -07:00