22 Aug, 2018

1 commit

  • 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
    Cc: Vlad Buslov
    Signed-off-by: Cong Wang
    Signed-off-by: David S. Miller

    Cong Wang
     

20 Aug, 2018

1 commit

  • Recently, ops->init() and ops->dump() of all actions were modified to
    always obtain tcf_lock when accessing private action state. Actions that
    don't depend on tcf_lock for synchronization with their data path use
    non-bh locking API. However, tcf_lock is also used to protect rate
    estimator stats in softirq context by timer callback.

    Change ops->init() and ops->dump() of all actions to disable bh when using
    tcf_lock to prevent deadlock reported by following lockdep warning:

    [ 105.470398] ================================
    [ 105.475014] WARNING: inconsistent lock state
    [ 105.479628] 4.18.0-rc8+ #664 Not tainted
    [ 105.483897] --------------------------------
    [ 105.488511] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
    [ 105.494871] swapper/16/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
    [ 105.500449] 00000000f86c012e (&(&p->tcfa_lock)->rlock){+.?.}, at: est_fetch_counters+0x3c/0xa0
    [ 105.509696] {SOFTIRQ-ON-W} state was registered at:
    [ 105.514925] _raw_spin_lock+0x2c/0x40
    [ 105.519022] tcf_bpf_init+0x579/0x820 [act_bpf]
    [ 105.523990] tcf_action_init_1+0x4e4/0x660
    [ 105.528518] tcf_action_init+0x1ce/0x2d0
    [ 105.532880] tcf_exts_validate+0x1d8/0x200
    [ 105.537416] fl_change+0x55a/0x268b [cls_flower]
    [ 105.542469] tc_new_tfilter+0x748/0xa20
    [ 105.546738] rtnetlink_rcv_msg+0x56a/0x6d0
    [ 105.551268] netlink_rcv_skb+0x18d/0x200
    [ 105.555628] netlink_unicast+0x2d0/0x370
    [ 105.559990] netlink_sendmsg+0x3b9/0x6a0
    [ 105.564349] sock_sendmsg+0x6b/0x80
    [ 105.568271] ___sys_sendmsg+0x4a1/0x520
    [ 105.572547] __sys_sendmsg+0xd7/0x150
    [ 105.576655] do_syscall_64+0x72/0x2c0
    [ 105.580757] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [ 105.586243] irq event stamp: 489296
    [ 105.590084] hardirqs last enabled at (489296): [] _raw_spin_unlock_irq+0x29/0x40
    [ 105.599765] hardirqs last disabled at (489295): [] _raw_spin_lock_irq+0x15/0x50
    [ 105.609277] softirqs last enabled at (489292): [] irq_enter+0x83/0xa0
    [ 105.618001] softirqs last disabled at (489293): [] irq_exit+0x140/0x190
    [ 105.626813]
    other info that might help us debug this:
    [ 105.633976] Possible unsafe locking scenario:

    [ 105.640526] CPU0
    [ 105.643325] ----
    [ 105.646125] lock(&(&p->tcfa_lock)->rlock);
    [ 105.650747]
    [ 105.653717] lock(&(&p->tcfa_lock)->rlock);
    [ 105.658514]
    *** DEADLOCK ***

    [ 105.665349] 1 lock held by swapper/16/0:
    [ 105.669629] #0: 00000000a640ad99 ((&est->timer)){+.-.}, at: call_timer_fn+0x10b/0x550
    [ 105.678200]
    stack backtrace:
    [ 105.683194] CPU: 16 PID: 0 Comm: swapper/16 Not tainted 4.18.0-rc8+ #664
    [ 105.690249] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017
    [ 105.698626] Call Trace:
    [ 105.701421]
    [ 105.703791] dump_stack+0x92/0xeb
    [ 105.707461] print_usage_bug+0x336/0x34c
    [ 105.711744] mark_lock+0x7c9/0x980
    [ 105.715500] ? print_shortest_lock_dependencies+0x2e0/0x2e0
    [ 105.721424] ? check_usage_forwards+0x230/0x230
    [ 105.726315] __lock_acquire+0x923/0x26f0
    [ 105.730597] ? debug_show_all_locks+0x240/0x240
    [ 105.735478] ? mark_lock+0x493/0x980
    [ 105.739412] ? check_chain_key+0x140/0x1f0
    [ 105.743861] ? __lock_acquire+0x836/0x26f0
    [ 105.748323] ? lock_acquire+0x12e/0x290
    [ 105.752516] lock_acquire+0x12e/0x290
    [ 105.756539] ? est_fetch_counters+0x3c/0xa0
    [ 105.761084] _raw_spin_lock+0x2c/0x40
    [ 105.765099] ? est_fetch_counters+0x3c/0xa0
    [ 105.769633] est_fetch_counters+0x3c/0xa0
    [ 105.773995] est_timer+0x87/0x390
    [ 105.777670] ? est_fetch_counters+0xa0/0xa0
    [ 105.782210] ? lock_acquire+0x12e/0x290
    [ 105.786410] call_timer_fn+0x161/0x550
    [ 105.790512] ? est_fetch_counters+0xa0/0xa0
    [ 105.795055] ? del_timer_sync+0xd0/0xd0
    [ 105.799249] ? __lock_is_held+0x93/0x110
    [ 105.803531] ? mark_held_locks+0x20/0xe0
    [ 105.807813] ? _raw_spin_unlock_irq+0x29/0x40
    [ 105.812525] ? est_fetch_counters+0xa0/0xa0
    [ 105.817069] ? est_fetch_counters+0xa0/0xa0
    [ 105.821610] run_timer_softirq+0x3c4/0x9f0
    [ 105.826064] ? lock_acquire+0x12e/0x290
    [ 105.830257] ? __bpf_trace_timer_class+0x10/0x10
    [ 105.835237] ? __lock_is_held+0x25/0x110
    [ 105.839517] __do_softirq+0x11d/0x7bf
    [ 105.843542] irq_exit+0x140/0x190
    [ 105.847208] smp_apic_timer_interrupt+0xac/0x3b0
    [ 105.852182] apic_timer_interrupt+0xf/0x20
    [ 105.856628]
    [ 105.859081] RIP: 0010:cpuidle_enter_state+0xd8/0x4d0
    [ 105.864395] Code: 46 ff 48 89 44 24 08 0f 1f 44 00 00 31 ff e8 cf ec 46 ff 80 7c 24 07 00 0f 85 1d 02 00 00 e8 9f 90 4b ff fb 66 0f 1f 44 00 00 8b 6c 24 08 4d 29 fd 0f 80 36 03 00 00 4c 89 e8 48 ba cf f7 53
    [ 105.884288] RSP: 0018:ffff8803ad94fd20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
    [ 105.892494] RAX: 0000000000000000 RBX: ffffe8fb300829c0 RCX: ffffffffb41e19e1
    [ 105.899988] RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8803ad9358ac
    [ 105.907503] RBP: ffffffffb6636300 R08: 0000000000000004 R09: 0000000000000000
    [ 105.914997] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000004
    [ 105.922487] R13: ffffffffb6636140 R14: ffffffffb66362d8 R15: 000000188d36091b
    [ 105.929988] ? trace_hardirqs_on_caller+0x141/0x2d0
    [ 105.935232] do_idle+0x28e/0x320
    [ 105.938817] ? arch_cpu_idle_exit+0x40/0x40
    [ 105.943361] ? mark_lock+0x8c1/0x980
    [ 105.947295] ? _raw_spin_unlock_irqrestore+0x32/0x60
    [ 105.952619] cpu_startup_entry+0xc2/0xd0
    [ 105.956900] ? cpu_in_idle+0x20/0x20
    [ 105.960830] ? _raw_spin_unlock_irqrestore+0x32/0x60
    [ 105.966146] ? trace_hardirqs_on_caller+0x141/0x2d0
    [ 105.971391] start_secondary+0x2b5/0x360
    [ 105.975669] ? set_cpu_sibling_map+0x1330/0x1330
    [ 105.980654] secondary_startup_64+0xa5/0xb0

    Taking tcf_lock in sample action with bh disabled causes lockdep to issue a
    warning regarding possible irq lock inversion dependency between tcf_lock,
    and psample_groups_lock that is taken when holding tcf_lock in sample init:

    [ 162.108959] Possible interrupt unsafe locking scenario:

    [ 162.116386] CPU0 CPU1
    [ 162.121277] ---- ----
    [ 162.126162] lock(psample_groups_lock);
    [ 162.130447] local_irq_disable();
    [ 162.136772] lock(&(&p->tcfa_lock)->rlock);
    [ 162.143957] lock(psample_groups_lock);
    [ 162.150813]
    [ 162.153808] lock(&(&p->tcfa_lock)->rlock);
    [ 162.158608]
    *** DEADLOCK ***

    In order to prevent potential lock inversion dependency between tcf_lock
    and psample_groups_lock, extract call to psample_group_get() from tcf_lock
    protected section in sample action init function.

    Fixes: 4e232818bd32 ("net: sched: act_mirred: remove dependency on rtnl lock")
    Fixes: 764e9a24480f ("net: sched: act_vlan: remove dependency on rtnl lock")
    Fixes: 729e01260989 ("net: sched: act_tunnel_key: remove dependency on rtnl lock")
    Fixes: d77284956656 ("net: sched: act_sample: remove dependency on rtnl lock")
    Fixes: e8917f437006 ("net: sched: act_gact: remove dependency on rtnl lock")
    Fixes: b6a2b971c0b0 ("net: sched: act_csum: remove dependency on rtnl lock")
    Fixes: 2142236b4584 ("net: sched: act_bpf: remove dependency on rtnl lock")
    Signed-off-by: Vlad Buslov
    Signed-off-by: David S. Miller

    Vlad Buslov
     

14 Aug, 2018

1 commit


12 Aug, 2018

1 commit

  • Use tcf lock to protect csum action struct private data from concurrent
    modification in init and dump. 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)

    Remove rtnl assertion that is no longer necessary.

    Signed-off-by: Vlad Buslov
    Signed-off-by: David S. Miller

    Vlad Buslov
     

31 Jul, 2018

1 commit

  • 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
    Acked-by: Jiri Pirko
    Signed-off-by: David S. Miller

    Paolo Abeni
     

21 Jul, 2018

1 commit


08 Jul, 2018

5 commits

  • 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
    Signed-off-by: Vlad Buslov
    Signed-off-by: Jiri Pirko
    Signed-off-by: David S. Miller

    Vlad Buslov
     
  • 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
    Signed-off-by: Vlad Buslov
    Signed-off-by: Jiri Pirko
    Signed-off-by: David S. Miller

    Vlad Buslov
     
  • 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
    Signed-off-by: Vlad Buslov
    Signed-off-by: Jiri Pirko
    Signed-off-by: David S. Miller

    Vlad Buslov
     
  • 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
    Signed-off-by: Vlad Buslov
    Signed-off-by: Jiri Pirko
    Signed-off-by: David S. Miller

    Vlad Buslov
     
  • 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
    Signed-off-by: Vlad Buslov
    Signed-off-by: Jiri Pirko
    Signed-off-by: David S. Miller

    Vlad Buslov
     

07 Jul, 2018

1 commit

  • the control action in the common member of struct tcf_csum must be a valid
    value, as it can contain the chain index when 'goto chain' is used. Ensure
    that the control action can be read as x->tcfa_action, when x is a pointer
    to struct tc_action and x->ops->type is TCA_ACT_CSUM, to prevent the
    following command:

    # tc filter add dev $h2 ingress protocol ip pref 1 handle 101 flower \
    > $tcflags dst_mac $h2mac action csum ip or tcp or udp or sctp goto chain 1

    from triggering a NULL pointer dereference when a matching packet is
    received.

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
    PGD 800000010416b067 P4D 800000010416b067 PUD 1041be067 PMD 0
    Oops: 0000 [#1] SMP PTI
    CPU: 0 PID: 3072 Comm: mausezahn Tainted: G E 4.18.0-rc2.auguri+ #421
    Hardware name: Hewlett-Packard HP Z220 CMT Workstation/1790, BIOS K51 v01.58 02/07/2013
    RIP: 0010:tcf_action_exec+0xb8/0x100
    Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
    RSP: 0018:ffffa020dea03c40 EFLAGS: 00010246
    RAX: 0000000020000001 RBX: ffffa020d7ccef00 RCX: 0000000000000054
    RDX: 0000000000000000 RSI: ffffa020ca5ae000 RDI: ffffa020d7ccef00
    RBP: ffffa020dea03e60 R08: 0000000000000000 R09: ffffa020dea03c9c
    R10: ffffa020dea03c78 R11: 0000000000000008 R12: ffffa020d3fe4f00
    R13: ffffa020d3fe4f08 R14: 0000000000000001 R15: ffffa020d53ca300
    FS: 00007f5a46942740(0000) GS:ffffa020dea00000(0000) knlGS:0000000000000000
    CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 0000000104218002 CR4: 00000000001606f0
    Call Trace:

    fl_classify+0x1ad/0x1c0 [cls_flower]
    ? arp_rcv+0x121/0x1b0
    ? __x2apic_send_IPI_dest+0x40/0x40
    ? smp_reschedule_interrupt+0x1c/0xd0
    ? reschedule_interrupt+0xf/0x20
    ? reschedule_interrupt+0xa/0x20
    ? device_is_rmrr_locked+0xe/0x50
    ? iommu_should_identity_map+0x49/0xd0
    ? __intel_map_single+0x30/0x140
    ? e1000e_update_rdt_wa.isra.52+0x22/0xb0 [e1000e]
    ? e1000_alloc_rx_buffers+0x233/0x250 [e1000e]
    ? kmem_cache_alloc+0x38/0x1c0
    tcf_classify+0x89/0x140
    __netif_receive_skb_core+0x5ea/0xb70
    ? enqueue_task_fair+0xb6/0x7d0
    ? process_backlog+0x97/0x150
    process_backlog+0x97/0x150
    net_rx_action+0x14b/0x3e0
    __do_softirq+0xde/0x2b4
    do_softirq_own_stack+0x2a/0x40

    do_softirq.part.18+0x49/0x50
    __local_bh_enable_ip+0x49/0x50
    __dev_queue_xmit+0x4ab/0x8a0
    ? wait_woken+0x80/0x80
    ? packet_sendmsg+0x38f/0x810
    ? __dev_queue_xmit+0x8a0/0x8a0
    packet_sendmsg+0x38f/0x810
    sock_sendmsg+0x36/0x40
    __sys_sendto+0x10e/0x140
    ? do_vfs_ioctl+0xa4/0x630
    ? syscall_trace_enter+0x1df/0x2e0
    ? __audit_syscall_exit+0x22a/0x290
    __x64_sys_sendto+0x24/0x30
    do_syscall_64+0x5b/0x180
    entry_SYSCALL_64_after_hwframe+0x44/0xa9
    RIP: 0033:0x7f5a45cbec93
    Code: 48 8b 0d 18 83 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c7 20 00 00 75 13 49 89 ca b8 2c 00 00 00 0f 05 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 2b f7 ff ff 48 89 04 24
    RSP: 002b:00007ffd0ee6d748 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
    RAX: ffffffffffffffda RBX: 0000000001161010 RCX: 00007f5a45cbec93
    RDX: 0000000000000062 RSI: 0000000001161322 RDI: 0000000000000003
    RBP: 00007ffd0ee6d780 R08: 00007ffd0ee6d760 R09: 0000000000000014
    R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000062
    R13: 0000000001161322 R14: 00007ffd0ee6d760 R15: 0000000000000003
    Modules linked in: act_csum act_gact cls_flower sch_ingress vrf veth act_tunnel_key(E) xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel snd_hda_codec_hdmi snd_hda_codec_realtek kvm snd_hda_codec_generic hp_wmi iTCO_wdt sparse_keymap rfkill mei_wdt iTCO_vendor_support wmi_bmof gpio_ich irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel snd_hda_intel crypto_simd cryptd snd_hda_codec glue_helper snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm pcspkr i2c_i801 snd_timer snd sg lpc_ich soundcore wmi mei_me
    mei ie31200_edac nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sr_mod cdrom sd_mod ahci libahci crc32c_intel i915 ixgbe serio_raw libata video dca i2c_algo_bit sfc drm_kms_helper syscopyarea mtd sysfillrect mdio sysimgblt fb_sys_fops drm e1000e i2c_core
    CR2: 0000000000000000
    ---[ end trace 3c9e9d1a77df4026 ]---
    RIP: 0010:tcf_action_exec+0xb8/0x100
    Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
    RSP: 0018:ffffa020dea03c40 EFLAGS: 00010246
    RAX: 0000000020000001 RBX: ffffa020d7ccef00 RCX: 0000000000000054
    RDX: 0000000000000000 RSI: ffffa020ca5ae000 RDI: ffffa020d7ccef00
    RBP: ffffa020dea03e60 R08: 0000000000000000 R09: ffffa020dea03c9c
    R10: ffffa020dea03c78 R11: 0000000000000008 R12: ffffa020d3fe4f00
    R13: ffffa020d3fe4f08 R14: 0000000000000001 R15: ffffa020d53ca300
    FS: 00007f5a46942740(0000) GS:ffffa020dea00000(0000) knlGS:0000000000000000
    CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 0000000104218002 CR4: 00000000001606f0
    Kernel panic - not syncing: Fatal exception in interrupt
    Kernel Offset: 0x26400000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
    ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

    Fixes: 9c5f69bbd75a ("net/sched: act_csum: don't use spinlock in the fast path")
    Signed-off-by: Davide Caratti
    Signed-off-by: David S. Miller

    Davide Caratti
     

03 May, 2018

1 commit


28 Mar, 2018

1 commit


23 Mar, 2018

1 commit

  • Fun set of conflict resolutions here...

    For the mac80211 stuff, these were fortunately just parallel
    adds. Trivially resolved.

    In drivers/net/phy/phy.c we had a bug fix in 'net' that moved the
    function phy_disable_interrupts() earlier in the file, whilst in
    'net-next' the phy_error() call from this function was removed.

    In net/ipv4/xfrm4_policy.c, David Ahern's changes to remove the
    'rt_table_id' member of rtable collided with a bug fix in 'net' that
    added a new struct member "rt_mtu_locked" which needs to be copied
    over here.

    The mlxsw driver conflict consisted of net-next separating
    the span code and definitions into separate files, whilst
    a 'net' bug fix made some changes to that moved code.

    The mlx5 infiniband conflict resolution was quite non-trivial,
    the RDMA tree's merge commit was used as a guide here, and
    here are their notes:

    ====================

    Due to bug fixes found by the syzkaller bot and taken into the for-rc
    branch after development for the 4.17 merge window had already started
    being taken into the for-next branch, there were fairly non-trivial
    merge issues that would need to be resolved between the for-rc branch
    and the for-next branch. This merge resolves those conflicts and
    provides a unified base upon which ongoing development for 4.17 can
    be based.

    Conflicts:
    drivers/infiniband/hw/mlx5/main.c - Commit 42cea83f9524
    (IB/mlx5: Fix cleanup order on unload) added to for-rc and
    commit b5ca15ad7e61 (IB/mlx5: Add proper representors support)
    add as part of the devel cycle both needed to modify the
    init/de-init functions used by mlx5. To support the new
    representors, the new functions added by the cleanup patch
    needed to be made non-static, and the init/de-init list
    added by the representors patch needed to be modified to
    match the init/de-init list changes made by the cleanup
    patch.
    Updates:
    drivers/infiniband/hw/mlx5/mlx5_ib.h - Update function
    prototypes added by representors patch to reflect new function
    names as changed by cleanup patch
    drivers/infiniband/hw/mlx5/ib_rep.c - Update init/de-init
    stage list to match new order from cleanup patch
    ====================

    Signed-off-by: David S. Miller

    David S. Miller
     

18 Mar, 2018

1 commit

  • when the following command

    # tc action add action csum udp continue index 100

    is run for the first time, and tcf_csum_init() fails allocating struct
    tcf_csum, tcf_csum_cleanup() calls kfree_rcu(NULL,...). This causes the
    following error:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
    IP: __call_rcu+0x23/0x2b0
    PGD 80000000740b4067 P4D 80000000740b4067 PUD 32e7f067 PMD 0
    Oops: 0002 [#1] SMP PTI
    Modules linked in: act_csum(E) act_vlan ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 mbcache jbd2 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec_generic pcbc snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer aesni_intel crypto_simd glue_helper cryptd snd joydev pcspkr virtio_balloon i2c_piix4 soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm virtio_blk drm virtio_net virtio_console ata_piix crc32c_intel libata virtio_pci serio_raw i2c_core virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: act_vlan]
    CPU: 2 PID: 5763 Comm: tc Tainted: G E 4.16.0-rc4.act_vlan.orig+ #403
    Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
    RIP: 0010:__call_rcu+0x23/0x2b0
    RSP: 0018:ffffb275803e77c0 EFLAGS: 00010246
    RAX: ffffffffc057b080 RBX: ffff9674bc6f5240 RCX: 00000000ffffffff
    RDX: ffffffff928a5f00 RSI: 0000000000000008 RDI: 0000000000000008
    RBP: 0000000000000008 R08: 0000000000000001 R09: 0000000000000044
    R10: 0000000000000220 R11: ffff9674b9ab4821 R12: 0000000000000000
    R13: ffffffff928a5f00 R14: 0000000000000000 R15: 0000000000000001
    FS: 00007fa6368d8740(0000) GS:ffff9674bfd00000(0000) knlGS:0000000000000000
    CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000010 CR3: 0000000073dec001 CR4: 00000000001606e0
    Call Trace:
    __tcf_idr_release+0x79/0xf0
    tcf_csum_init+0xfb/0x180 [act_csum]
    tcf_action_init_1+0x2cc/0x430
    tcf_action_init+0xd3/0x1b0
    tc_ctl_action+0x18b/0x240
    rtnetlink_rcv_msg+0x29c/0x310
    ? _cond_resched+0x15/0x30
    ? __kmalloc_node_track_caller+0x1b9/0x270
    ? rtnl_calcit.isra.28+0x100/0x100
    netlink_rcv_skb+0xd2/0x110
    netlink_unicast+0x17c/0x230
    netlink_sendmsg+0x2cd/0x3c0
    sock_sendmsg+0x30/0x40
    ___sys_sendmsg+0x27a/0x290
    ? filemap_map_pages+0x34a/0x3a0
    ? __handle_mm_fault+0xbfd/0xe20
    __sys_sendmsg+0x51/0x90
    do_syscall_64+0x6e/0x1a0
    entry_SYSCALL_64_after_hwframe+0x3d/0xa2
    RIP: 0033:0x7fa635ce9ba0
    RSP: 002b:00007ffc185b0fc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
    RAX: ffffffffffffffda RBX: 00007ffc185b10f0 RCX: 00007fa635ce9ba0
    RDX: 0000000000000000 RSI: 00007ffc185b1040 RDI: 0000000000000003
    RBP: 000000005aaa85e0 R08: 0000000000000002 R09: 0000000000000000
    R10: 00007ffc185b0a20 R11: 0000000000000246 R12: 0000000000000000
    R13: 00007ffc185b1104 R14: 0000000000000001 R15: 0000000000669f60
    Code: 5d e9 42 da ff ff 66 90 0f 1f 44 00 00 41 57 41 56 41 55 49 89 d5 41 54 55 48 89 fd 53 48 83 ec 08 40 f6 c7 07 0f 85 19 02 00 00 89 75 08 48 c7 45 00 00 00 00 00 9c 58 0f 1f 44 00 00 49 89
    RIP: __call_rcu+0x23/0x2b0 RSP: ffffb275803e77c0
    CR2: 0000000000000010

    fix this in tcf_csum_cleanup(), ensuring that kfree_rcu(param, ...) is
    called only when param is not NULL.

    Fixes: 9c5f69bbd75a ("net/sched: act_csum: don't use spinlock in the fast path")
    Signed-off-by: Davide Caratti
    Acked-by: Jiri Pirko
    Signed-off-by: David S. Miller

    Davide Caratti
     

10 Mar, 2018

1 commit

  • As well as the basic conversion, I noticed that a lot of the
    SCTP code checks gso_type without first checking skb_is_gso()
    so I have added that where appropriate.

    Also, document the helper.

    Cc: Daniel Borkmann
    Cc: Marcelo Ricardo Leitner
    Signed-off-by: Daniel Axtens
    Signed-off-by: David S. Miller

    Daniel Axtens
     

28 Feb, 2018

1 commit

  • 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
    Signed-off-by: David S. Miller

    Kirill Tkhai
     

17 Feb, 2018

4 commits


24 Jan, 2018

2 commits


14 Dec, 2017

1 commit


24 Nov, 2017

1 commit

  • Tuntap and similar devices can inject GSO packets. Accept type
    VIRTIO_NET_HDR_GSO_UDP, even though not generating UFO natively.

    Processes are expected to use feature negotiation such as TUNSETOFFLOAD
    to detect supported offload types and refrain from injecting other
    packets. This process breaks down with live migration: guest kernels
    do not renegotiate flags, so destination hosts need to expose all
    features that the source host does.

    Partially revert the UFO removal from 182e0b6b5846~1..d9d30adf5677.
    This patch introduces nearly(*) no new code to simplify verification.
    It brings back verbatim tuntap UFO negotiation, VIRTIO_NET_HDR_GSO_UDP
    insertion and software UFO segmentation.

    It does not reinstate protocol stack support, hardware offload
    (NETIF_F_UFO), SKB_GSO_UDP tunneling in SKB_GSO_SOFTWARE or reception
    of VIRTIO_NET_HDR_GSO_UDP packets in tuntap.

    To support SKB_GSO_UDP reappearing in the stack, also reinstate
    logic in act_csum and openvswitch. Achieve equivalence with v4.13 HEAD
    by squashing in commit 939912216fa8 ("net: skb_needs_check() removes
    CHECKSUM_UNNECESSARY check for tx.") and reverting commit 8d63bee643f1
    ("net: avoid skb_warn_bad_offload false positives on UFO").

    (*) To avoid having to bring back skb_shinfo(skb)->ip6_frag_id,
    ipv6_proxy_select_ident is changed to return a __be32 and this is
    assigned directly to the frag_hdr. Also, SKB_GSO_UDP is inserted
    at the end of the enum to minimize code churn.

    Tested
    Booted a v4.13 guest kernel with QEMU. On a host kernel before this
    patch `ethtool -k eth0` shows UFO disabled. After the patch, it is
    enabled, same as on a v4.13 host kernel.

    A UFO packet sent from the guest appears on the tap device:
    host:
    nc -l -p -u 8000 &
    tcpdump -n -i tap0

    guest:
    dd if=/dev/zero of=payload.txt bs=1 count=2000
    nc -u 192.16.1.1 8000 < payload.txt

    Direct tap to tap transmission of VIRTIO_NET_HDR_GSO_UDP succeeds,
    packets arriving fragmented:

    ./with_tap_pair.sh ./tap_send_ufo tap0 tap1
    (from https://github.com/wdebruij/kerneltools/tree/master/tests)

    Changes
    v1 -> v2
    - simplified set_offload change (review comment)
    - documented test procedure

    Link: http://lkml.kernel.org/r/
    Fixes: fb652fdfe837 ("macvlan/macvtap: Remove NETIF_F_UFO advertisement.")
    Reported-by: Michal Kubecek
    Signed-off-by: Willem de Bruijn
    Acked-by: Jason Wang
    Signed-off-by: David S. Miller

    Willem de Bruijn
     

09 Nov, 2017

1 commit

  • This reverts commit ceffcc5e254b450e6159f173e4538215cebf1b59.
    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
    Cc: Jamal Hadi Salim
    Cc: Jiri Pirko
    Signed-off-by: Cong Wang
    Signed-off-by: David S. Miller

    Cong Wang
     

03 Nov, 2017

1 commit

  • 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: ddf97ccdd7cb ("net_sched: add network namespace support for tc actions")
    Reported-by: Lucas Bates
    Tested-by: Lucas Bates
    Cc: Jamal Hadi Salim
    Cc: Jiri Pirko
    Signed-off-by: Cong Wang
    Signed-off-by: David S. Miller

    Cong Wang
     

31 Aug, 2017

1 commit

  • 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
    Signed-off-by: Jiri Pirko
    Acked-by: Jamal Hadi Salim
    Signed-off-by: David S. Miller

    Chris Mi
     

18 Jul, 2017

1 commit


20 May, 2017

1 commit

  • skb->csum_not_inet carries the indication on which algorithm is needed to
    compute checksum on skb in the transmit path, when skb->ip_summed is equal
    to CHECKSUM_PARTIAL. If skb carries a SCTP packet and crc32c hasn't been
    yet written in L4 header, skb->csum_not_inet is assigned to 1; otherwise,
    assume Internet Checksum is needed and thus set skb->csum_not_inet to 0.

    Suggested-by: Tom Herbert
    Signed-off-by: Davide Caratti
    Acked-by: Tom Herbert
    Signed-off-by: David S. Miller

    Davide Caratti
     

14 Apr, 2017

1 commit


24 Mar, 2017

1 commit

  • after act_csum computes the checksum on skbs carrying GSO TCP/UDP packets,
    subsequent segmentation fails because skb_needs_check(skb, true) returns
    true. Because of that, skb_warn_bad_offload() is invoked and the following
    message is displayed:

    WARNING: CPU: 3 PID: 28 at net/core/dev.c:2553 skb_warn_bad_offload+0xf0/0xfd

    [] skb_warn_bad_offload+0xf0/0xfd
    [] __skb_gso_segment+0xec/0x110
    [] validate_xmit_skb+0x12d/0x2b0
    [] validate_xmit_skb_list+0x42/0x70
    [] sch_direct_xmit+0xd0/0x1b0
    [] __qdisc_run+0x120/0x270
    [] __dev_queue_xmit+0x23d/0x690
    [] dev_queue_xmit+0x10/0x20

    Since GSO is able to compute checksum on individual segments of such skbs,
    we can simply skip mangling the packet.

    Signed-off-by: Davide Caratti
    Signed-off-by: David S. Miller

    Davide Caratti
     

10 Jan, 2017

1 commit


18 Nov, 2016

1 commit

  • 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
    Signed-off-by: David S. Miller

    Alexey Dobriyan
     

20 Sep, 2016

1 commit


26 Jul, 2016

1 commit

  • 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
    Signed-off-by: Cong Wang
    Signed-off-by: David S. Miller

    WANG Cong
     

08 Jun, 2016

3 commits