1. 02 Oct, 2014 26 commits
    • Todd Fujinaka's avatar
      igb: bump version to 5.2.15 · b5d130c4
      Todd Fujinaka authored
      Bump version
      Signed-off-by: default avatarTodd Fujinaka <todd.fujinaka@intel.com>
      Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      b5d130c4
    • Rick Jones's avatar
      i40e/igb: Convert to dev_consume_skb_any() · a81fb049
      Rick Jones authored
      Convert two more Intel NIC drivers to dev_consume_skb_any() to help
      make dropped packet profiling sane.
      Signed-off-by: default avatarRick Jones <rick.jones2@hp.com>
      Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
      Tested-by: default avatarJim Young <jamesx.m.young@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      a81fb049
    • Bernhard Kaindl's avatar
      igb: remove blocking phy read from inside spinlock · 7acf6318
      Bernhard Kaindl authored
      Remove a source of latency spikes (in my case up to 10ms) by not calling
      code that uses mdelay() for feeding a phy statistic (rx errors for idle
      symbols - not data -> idle_errors) while being called with a spinlock held.
      
      As idle_errors isn't read, this patch only removes unused code and data.
      
      Later, more complicated changes may be applied to address the spinlock and
      allow for some PHY diagnostics by harvesting this PHY stats register fully.
      
      This patch is designed to fix the issue and be safe for longterm/stable.
      
      For the Intel e1000e driver, the same change was applied in 2008 with
      commit 23033fad ("e1000e: remove phy read from inside spinlock").
      
      The mdelay is triggered by HW/SW semaphores, thus it depends on the HW.
      
      I've HW that triggers it even when idle. Others may trigger it only e.g.
      when Ethernet ports aquire or loose the link or on ifconfig up / down.
      We've noticed this first from delays in frame rx/tx due to the mdelay().
      
      Example command for checking if the issue is triggered: cyclictest -Smp1
      (Look for occasional "Max:" values > 4000 or use -b 4000 to stop if greater)
      
      It was observed with I350 ports connected to other I350 ports, but not
      if driver and EEPROM was modified to run the I350 in EEPROM-less mode.
      
      phy_stats.idle_errors and .receive_errors (isn't touched) occupy 64 not
      used bits in the adapter struct: Their allocation may be removed as well.
      
      Cc: Carolyn Wyborny <carolyn.wyborny@intel.com>
      Cc: Todd Fujinaka <todd.fujinaka@intel.com>
      Fixes: 12dcd86b ("igb: fix stats handling") (this added the spin_lock)
      Signed-off-by: default avatarBernhard Kaindl <bk-linux@use.startmail.com>
      Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      7acf6318
    • Ethan Zhao's avatar
      ixgbe: delete one duplicate marcro definition of IXGBE_MAX_L2A_QUEUES · 3463de10
      Ethan Zhao authored
      There is typo in ixgbe.h, two marcro definition of IXGBE_MAX_L2A_QUEUES to 4,
      delete one, clear the compiler warning.
      Signed-off-by: default avatarEthan Zhao <ethan.zhao@oracle.com>
      Tested-by: default avatarPhil Schmitt <phillip.j.schmitt@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      3463de10
    • Emil Tantilov's avatar
      ixgbe: fix setting of TXDCTL.WTRHESH when ITR is set to 0 and no BQL · ffefa9f6
      Emil Tantilov authored
      This patch consolidates the logic behind dynamically setting TXDCTL.WTHRESH
      depending on interrupt throttle rate (ITR) setting regardless of BQL.
      
      Previously TXDCTL.WTHRESH was dynamically being set only with BQL being
      enabled, but we have to set it regardless of BQL when ITR is low to avoid
      Tx stalls/hangs.
      
      CC: John Greene <jogreene@redhat.com>
      Reported by: Masayuki Gouji <gouji.masayuki@jp.fujitsu.com>
      Signed-off-by: default avatarEmil Tantilov <emil.s.tantilov@intel.com>
      Tested-by: default avatarPhil Schmitt <phillip.j.schmitt@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      ffefa9f6
    • Emil Tantilov's avatar
      ixgbe: remove wait loop on autoneg for copper devices · 340c5203
      Emil Tantilov authored
      This patch removes couple of wait loops on autoneg that are not needed.
      
      During validation we noticed that the loops always time out, so there
      should be no user impact.
      Signed-off-by: default avatarEmil Tantilov <emil.s.tantilov@intel.com>
      Tested-by: default avatarPhil Schmitt <phillip.j.schmitt@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      340c5203
    • Rick Jones's avatar
      ixgbe: Convert the normal transmit complete path to dev_consume_skb_any() · fe1f2a97
      Rick Jones authored
      Convert the normal packet completion path to dev_consume_skb_any() so
      packet drop profiling via dropwatch or perf top -G -e skb_kfree_skb
      is not cluttered with false hits.
      
      Compile tested only.  There is a dev_kfree_skb_any() in the routine
      ixgbe_ptp_tx_hwtstamp() in ixgbe_ptp.c that looks like a conversion
      candidate but I wasn't familiar enough with the code to pull the
      trigger.
      Signed-off-by: default avatarRick Jones <rick.jones2@hp.com>
      Tested-by: default avatarPhil Schmitt <phillip.j.schmitt@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      fe1f2a97
    • Alexander Duyck's avatar
      fm10k: Correctly set the number of Tx queues · c9d49940
      Alexander Duyck authored
      The number of Tx queues was not being updated due to some issues when
      generating the patches.  This change makes sure to add the lines necessary
      to update the number of Tx queues correctly.
      Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
      Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      c9d49940
    • Alexander Duyck's avatar
      fm10k: Reduce buffer size when pages are larger than 4K · fd333962
      Alexander Duyck authored
      This change reduces the buffer size to 2K for all page sizes.  The basic
      idea is that since most frames only have a 1500 MTU supporting a buffer
      size larger than this is somewhat wasteful.  As such I have reduced the
      size to 2K for all page sizes which will allow for more uses per page.
      Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
      Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      fd333962
    • Petri Gynther's avatar
    • Petri Gynther's avatar
      net: bcmgenet: fix bcmgenet_put_tx_csum() · bc23333b
      Petri Gynther authored
      bcmgenet_put_tx_csum() needs to return skb pointer back to the caller
      because it reallocates a new one in case of lack of skb headroom.
      Signed-off-by: default avatarPetri Gynther <pgynther@google.com>
      Acked-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bc23333b
    • Alexei Starovoitov's avatar
      net: pktgen: packet bursting via skb->xmit_more · 38b2cf29
      Alexei Starovoitov authored
      This patch demonstrates the effect of delaying update of HW tailptr.
      (based on earlier patch by Jesper)
      
      burst=1 is the default. It sends one packet with xmit_more=false
      burst=2 sends one packet with xmit_more=true and
              2nd copy of the same packet with xmit_more=false
      burst=3 sends two copies of the same packet with xmit_more=true and
              3rd copy with xmit_more=false
      
      Performance with ixgbe (usec 30):
      burst=1  tx:9.2 Mpps
      burst=2  tx:13.5 Mpps
      burst=3  tx:14.5 Mpps full 10G line rate
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Acked-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      38b2cf29
    • Florian Fainelli's avatar
      net: bridge: add a br_set_state helper function · 775dd692
      Florian Fainelli authored
      In preparation for being able to propagate port states to e.g: notifiers
      or other kernel parts, do not manipulate the port state directly, but
      instead use a helper function which will allow us to do a bit more than
      just setting the state.
      Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      775dd692
    • WANG Cong's avatar
      net_sched: avoid calling tcf_unbind_filter() in call_rcu callback · a0efb80c
      WANG Cong authored
      This fixes the following crash:
      
      [   63.976822] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
      [   63.980094] CPU: 1 PID: 15 Comm: ksoftirqd/1 Not tainted 3.17.0-rc6+ #648
      [   63.980094] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
      [   63.980094] task: ffff880117dea690 ti: ffff880117dfc000 task.ti: ffff880117dfc000
      [   63.980094] RIP: 0010:[<ffffffff817e6d07>]  [<ffffffff817e6d07>] u32_destroy_key+0x27/0x6d
      [   63.980094] RSP: 0018:ffff880117dffcc0  EFLAGS: 00010202
      [   63.980094] RAX: ffff880117dea690 RBX: ffff8800d02e0820 RCX: 0000000000000000
      [   63.980094] RDX: 0000000000000001 RSI: 0000000000000002 RDI: 6b6b6b6b6b6b6b6b
      [   63.980094] RBP: ffff880117dffcd0 R08: 0000000000000000 R09: 0000000000000000
      [   63.980094] R10: 00006c0900006ba8 R11: 00006ba100006b9d R12: 0000000000000001
      [   63.980094] R13: ffff8800d02e0898 R14: ffffffff817e6d4d R15: ffff880117387a30
      [   63.980094] FS:  0000000000000000(0000) GS:ffff88011a800000(0000) knlGS:0000000000000000
      [   63.980094] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
      [   63.980094] CR2: 00007f07e6732fed CR3: 000000011665b000 CR4: 00000000000006e0
      [   63.980094] Stack:
      [   63.980094]  ffff88011a9cd300 ffffffff82051ac0 ffff880117dffce0 ffffffff817e6d68
      [   63.980094]  ffff880117dffd70 ffffffff810cb4c7 ffffffff810cb3cd ffff880117dfffd8
      [   63.980094]  ffff880117dea690 ffff880117dea690 ffff880117dfffd8 000000000000000a
      [   63.980094] Call Trace:
      [   63.980094]  [<ffffffff817e6d68>] u32_delete_key_freepf_rcu+0x1b/0x1d
      [   63.980094]  [<ffffffff810cb4c7>] rcu_process_callbacks+0x3bb/0x691
      [   63.980094]  [<ffffffff810cb3cd>] ? rcu_process_callbacks+0x2c1/0x691
      [   63.980094]  [<ffffffff817e6d4d>] ? u32_destroy_key+0x6d/0x6d
      [   63.980094]  [<ffffffff810780a4>] __do_softirq+0x142/0x323
      [   63.980094]  [<ffffffff810782a8>] run_ksoftirqd+0x23/0x53
      [   63.980094]  [<ffffffff81092126>] smpboot_thread_fn+0x203/0x221
      [   63.980094]  [<ffffffff81091f23>] ? smpboot_unpark_thread+0x33/0x33
      [   63.980094]  [<ffffffff8108e44d>] kthread+0xc9/0xd1
      [   63.980094]  [<ffffffff819e00ea>] ? do_wait_for_common+0xf8/0x125
      [   63.980094]  [<ffffffff8108e384>] ? __kthread_parkme+0x61/0x61
      [   63.980094]  [<ffffffff819e43ec>] ret_from_fork+0x7c/0xb0
      [   63.980094]  [<ffffffff8108e384>] ? __kthread_parkme+0x61/0x61
      
      tp could be freed in call_rcu callback too, the order is not guaranteed.
      
      John Fastabend says:
      
      ====================
      Its worth noting why this is safe. Any running schedulers will either
      read the valid class field or it will be zeroed.
      
      All schedulers today when the class is 0 do a lookup using the
      same call used by the tcf_exts_bind(). So even if we have a running
      classifier hit the null class pointer it will do a lookup and get
      to the same result. This is particularly fragile at the moment because
      the only way to verify this is to audit the schedulers call sites.
      ====================
      
      Cc: John Fastabend <john.r.fastabend@intel.com>
      Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
      Acked-by: default avatarJohn Fastabend <john.r.fastabend@intel.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a0efb80c
    • WANG Cong's avatar
      net_sched: fix another crash in cls_tcindex · 6e056569
      WANG Cong authored
      This patch fixes the following crash:
      
      [  166.670795] BUG: unable to handle kernel NULL pointer dereference at           (null)
      [  166.674230] IP: [<ffffffff814b739f>] __list_del_entry+0x5c/0x98
      [  166.674230] PGD d0ea5067 PUD ce7fc067 PMD 0
      [  166.674230] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
      [  166.674230] CPU: 1 PID: 775 Comm: tc Not tainted 3.17.0-rc6+ #642
      [  166.674230] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
      [  166.674230] task: ffff8800d03c4d20 ti: ffff8800cae7c000 task.ti: ffff8800cae7c000
      [  166.674230] RIP: 0010:[<ffffffff814b739f>]  [<ffffffff814b739f>] __list_del_entry+0x5c/0x98
      [  166.674230] RSP: 0018:ffff8800cae7f7d0  EFLAGS: 00010207
      [  166.674230] RAX: 0000000000000000 RBX: ffff8800cba8d700 RCX: ffff8800cba8d700
      [  166.674230] RDX: 0000000000000000 RSI: dead000000200200 RDI: ffff8800cba8d700
      [  166.674230] RBP: ffff8800cae7f7d0 R08: 0000000000000001 R09: 0000000000000001
      [  166.674230] R10: 0000000000000000 R11: 000000000000859a R12: ffffffffffffffe8
      [  166.674230] R13: ffff8800cba8c5b8 R14: 0000000000000001 R15: ffff8800cba8d700
      [  166.674230] FS:  00007fdb5f04a740(0000) GS:ffff88011a800000(0000) knlGS:0000000000000000
      [  166.674230] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
      [  166.674230] CR2: 0000000000000000 CR3: 00000000cf929000 CR4: 00000000000006e0
      [  166.674230] Stack:
      [  166.674230]  ffff8800cae7f7e8 ffffffff814b73e8 ffff8800cba8d6e8 ffff8800cae7f828
      [  166.674230]  ffffffff817caeec 0000000000000046 ffff8800cba8c5b0 ffff8800cba8c5b8
      [  166.674230]  0000000000000000 0000000000000001 ffff8800cf8e33e8 ffff8800cae7f848
      [  166.674230] Call Trace:
      [  166.674230]  [<ffffffff814b73e8>] list_del+0xd/0x2b
      [  166.674230]  [<ffffffff817caeec>] tcf_action_destroy+0x4c/0x71
      [  166.674230]  [<ffffffff817ca0ce>] tcf_exts_destroy+0x20/0x2d
      [  166.674230]  [<ffffffff817ec2b5>] tcindex_delete+0x196/0x1b7
      
      struct list_head can not be simply copied and we should always init it.
      
      Cc: John Fastabend <john.r.fastabend@intel.com>
      Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
      Acked-by: default avatarJohn Fastabend <john.r.fastabend@intel.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      6e056569
    • David S. Miller's avatar
      Merge branch 'udp_gso' · 25e379c4
      David S. Miller authored
      Tom Herbert says:
      
      ====================
      udp: Generalize GSO for UDP tunnels
      
      This patch set generalizes the UDP tunnel segmentation functions so
      that they can work with various protocol encapsulations. The primary
      change is to set the inner_protocol field in the skbuff when creating
      the encapsulated packet, and then in skb_udp_tunnel_segment this data
      is used to determine the function for segmenting the encapsulated
      packet. The inner_protocol field is overloaded to take either an
      Ethertype or IP protocol.
      
      The inner_protocol is set on transmit using skb_set_inner_ipproto or
      skb_set_inner_protocol functions. VXLAN and IP tunnels (for fou GSO)
      were modified to call these.
      
      Notes:
        - GSO for GRE/UDP where GRE checksum is enabled does not work.
          Handling this will require some special case code.
        - Software GSO now supports many varieties of encapsulation with
          SKB_GSO_UDP_TUNNEL{_CSUM}. We still need a mechanism to query
          for device support of particular combinations (I intend to
          add ndo_gso_check for that).
        - MPLS seems to be the only previous user of inner_protocol. I don't
          believe these patches can affect that. For supporting GSO with
          MPLS over UDP, the inner_protocol should be set using the
          helper functions in this patch.
        - GSO for L2TP/UDP should also be straightforward now.
      
      v2:
        - Respin for Eric's restructuring of skbuff.
      
      Tested GRE, IPIP, and SIT over fou as well as VLXAN. This was
      done using 200 TCP_STREAMs in netperf.
      
       GRE
          IPv4, FOU, UDP checksum enabled
            TCP_STREAM TSO enabled on tun interface
              14.04% TX CPU utilization
              13.17% RX CPU utilization
              9211 Mbps
            TCP_STREAM TSO disabled on tun interface
              27.82% TX CPU utilization
              25.41% RX CPU utilization
              9336 Mbps
          IPv4, FOU, UDP checksum disabled
            TCP_STREAM TSO enabled on tun interface
              13.14% TX CPU utilization
              23.18% RX CPU utilization
              9277 Mbps
            TCP_STREAM TSO disabled on tun interface
              30.00% TX CPU utilization
              31.28% RX CPU utilization
              9327 Mbps
      
        IPIP
          FOU, UDP checksum enabled
            TCP_STREAM TSO enabled on tun interface
              15.28% TX CPU utilization
              13.92% RX CPU utilization
              9342 Mbps
            TCP_STREAM TSO disabled on tun interface
              27.82% TX CPU utilization
              25.41% RX CPU utilization
              9336 Mbps
          FOU, UDP checksum disabled
            TCP_STREAM TSO enabled on tun interface
              15.08% TX CPU utilization
              24.64% RX CPU utilization
              9226 Mbps
            TCP_STREAM TSO disabled on tun interface
              30.00% TX CPU utilization
              31.28% RX CPU utilization
              9327 Mbps
      
        SIT
          FOU, UDP checksum enabled
            TCP_STREAM TSO enabled on tun interface
              14.47% TX CPU utilization
              14.58% RX CPU utilization
              9106 Mbps
            TCP_STREAM TSO disabled on tun interface
              31.82% TX CPU utilization
              30.82% RX CPU utilization
              9204 Mbps
          FOU, UDP checksum disabled
            TCP_STREAM TSO enabled on tun interface
              15.70% TX CPU utilization
              27.93% RX CPU utilization
              9097 Mbps
            TCP_STREAM TSO disabled on tun interface
              33.48% TX CPU utilization
              37.36% RX CPU utilization
              9197 Mbps
      
         VXLAN
            TCP_STREAM TSO enabled on tun interface
              16.42% TX CPU utilization
              23.66% RX CPU utilization
              9081 Mbps
            TCP_STREAM TSO disabled on tun interface
              30.32% TX CPU utilization
              30.55% RX CPU utilization
              9185 Mbps
      
         Baseline (no encp, TSO and LRO enabled)
            TCP_STREAM
              11.85% TX CPU utilization
              15.13% RX CPU utilization
              9452 Mbps
      ====================
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      25e379c4
    • Tom Herbert's avatar
      vxlan: Set inner protocol before transmit · 996c9fd1
      Tom Herbert authored
      Call skb_set_inner_protocol to set inner Ethernet protocol to
      ETH_P_TEB before transmit. This is needed for GSO with UDP tunnels.
      Signed-off-by: default avatarTom Herbert <therbert@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      996c9fd1
    • Tom Herbert's avatar
      gre: Set inner protocol in v4 and v6 GRE transmit · 54bc9bac
      Tom Herbert authored
      Call skb_set_inner_protocol to set inner Ethernet protocol to
      protocol being encapsulation by GRE before tunnel_xmit. This is
      needed for GSO if UDP encapsulation (fou) is being done.
      Signed-off-by: default avatarTom Herbert <therbert@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      54bc9bac
    • Tom Herbert's avatar
      ipip: Set inner IP protocol in ipip · 077c5a09
      Tom Herbert authored
      Call skb_set_inner_ipproto to set inner IP protocol to IPPROTO_IPV4
      before tunnel_xmit. This is needed if UDP encapsulation (fou) is
      being done.
      Signed-off-by: default avatarTom Herbert <therbert@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      077c5a09
    • Tom Herbert's avatar
      sit: Set inner IP protocol in sit · 469471cd
      Tom Herbert authored
      Call skb_set_inner_ipproto to set inner IP protocol to IPPROTO_IPV6
      before tunnel_xmit. This is needed if UDP encapsulation (fou) is
      being done.
      Signed-off-by: default avatarTom Herbert <therbert@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      469471cd
    • Tom Herbert's avatar
      udp: Generalize skb_udp_segment · 8bce6d7d
      Tom Herbert authored
      skb_udp_segment is the function called from udp4_ufo_fragment to
      segment a UDP tunnel packet. This function currently assumes
      segmentation is transparent Ethernet bridging (i.e. VXLAN
      encapsulation). This patch generalizes the function to
      operate on either Ethertype or IP protocol.
      
      The inner_protocol field must be set to the protocol of the inner
      header. This can now be either an Ethertype or an IP protocol
      (in a union). A new flag in the skbuff indicates which type is
      effective. skb_set_inner_protocol and skb_set_inner_ipproto
      helper functions were added to set the inner_protocol. These
      functions are called from the point where the tunnel encapsulation
      is occuring.
      
      When skb_udp_tunnel_segment is called, the function to segment the
      inner packet is selected based on the inner IP or Ethertype. In the
      case of an IP protocol encapsulation, the function is derived from
      inet[6]_offloads. In the case of Ethertype, skb->protocol is
      set to the inner_protocol and skb_mac_gso_segment is called. (GRE
      currently does this, but it might be possible to lookup the protocol
      in offload_base and call the appropriate segmenation function
      directly).
      Signed-off-by: default avatarTom Herbert <therbert@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8bce6d7d
    • David S. Miller's avatar
      Merge branch 'bpf-next' · f44d61cd
      David S. Miller authored
      Alexei Starovoitov says:
      
      ====================
      bpf: add search pruning optimization and tests
      
      patch #1 commit log explains why eBPF verifier has to examine some
      instructions multiple times and describes the search pruning optimization
      that improves verification speed for branchy programs and allows more
      complex programs to be verified successfully.
      This patch completes the core verifier logic.
      
      patch #2 adds more verifier tests related to branches and search pruning
      
      I'm still working on Andy's 'bitmask for stack slots' suggestion. It will be
      done on top of this patch.
      
      The current verifier algorithm is brute force depth first search with
      state pruning. If anyone can come up with another algorithm that demonstrates
      better results, we'll replace the algorithm without affecting user space.
      
      Note verifier doesn't guarantee that all possible valid programs are accepted.
      Overly complex programs may still be rejected.
      Verifier improvements/optimizations will guarantee that if a program
      was passing verification in the past, it will still be passing.
      ====================
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f44d61cd
    • Alexei Starovoitov's avatar
      bpf: add tests to verifier testsuite · fd10c2ef
      Alexei Starovoitov authored
      add 4 extra tests to cover jump verification better
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      fd10c2ef
    • Alexei Starovoitov's avatar
      bpf: add search pruning optimization to verifier · f1bca824
      Alexei Starovoitov authored
      consider C program represented in eBPF:
      int filter(int arg)
      {
          int a, b, c, *ptr;
      
          if (arg == 1)
              ptr = &a;
          else if (arg == 2)
              ptr = &b;
          else
              ptr = &c;
      
          *ptr = 0;
          return 0;
      }
      eBPF verifier has to follow all possible paths through the program
      to recognize that '*ptr = 0' instruction would be safe to execute
      in all situations.
      It's doing it by picking a path towards the end and observes changes
      to registers and stack at every insn until it reaches bpf_exit.
      Then it comes back to one of the previous branches and goes towards
      the end again with potentially different values in registers.
      When program has a lot of branches, the number of possible combinations
      of branches is huge, so verifer has a hard limit of walking no more
      than 32k instructions. This limit can be reached and complex (but valid)
      programs could be rejected. Therefore it's important to recognize equivalent
      verifier states to prune this depth first search.
      
      Basic idea can be illustrated by the program (where .. are some eBPF insns):
          1: ..
          2: if (rX == rY) goto 4
          3: ..
          4: ..
          5: ..
          6: bpf_exit
      In the first pass towards bpf_exit the verifier will walk insns: 1, 2, 3, 4, 5, 6
      Since insn#2 is a branch the verifier will remember its state in verifier stack
      to come back to it later.
      Since insn#4 is marked as 'branch target', the verifier will remember its state
      in explored_states[4] linked list.
      Once it reaches insn#6 successfully it will pop the state recorded at insn#2 and
      will continue.
      Without search pruning optimization verifier would have to walk 4, 5, 6 again,
      effectively simulating execution of insns 1, 2, 4, 5, 6
      With search pruning it will check whether state at #4 after jumping from #2
      is equivalent to one recorded in explored_states[4] during first pass.
      If there is an equivalent state, verifier can prune the search at #4 and declare
      this path to be safe as well.
      In other words two states at #4 are equivalent if execution of 1, 2, 3, 4 insns
      and 1, 2, 4 insns produces equivalent registers and stack.
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f1bca824
    • Nimrod Andy's avatar
      net: fec: implement rx_copybreak to improve rx performance · 1b7bde6d
      Nimrod Andy authored
      - Copy short frames and keep the buffers mapped, re-allocate skb instead of
        memory copy for long frames.
      - Add support for setting/getting rx_copybreak using generic ethtool tunable
      
      Changes V3:
      * As Eric Dumazet's suggestion that removing the copybreak module parameter
        and only keep the ethtool API support for rx_copybreak.
      
      Changes V2:
      * Implements rx_copybreak
      * Rx_copybreak provides module parameter to change this value
      * Add tunable_ops support for rx_copybreak
      Signed-off-by: default avatarFugang Duan <B38611@freescale.com>
      Signed-off-by: default avatarFrank Li <Frank.Li@freescale.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1b7bde6d
    • Eric Dumazet's avatar
      net: avoid one atomic operation in skb_clone() · ce1a4ea3
      Eric Dumazet authored
      Fast clone cloning can actually avoid an atomic_inc(), if we
      guarantee prior clone_ref value is 1.
      
      This requires a change kfree_skbmem(), to perform the
      atomic_dec_and_test() on clone_ref before setting fclone to
      SKB_FCLONE_UNAVAILABLE.
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ce1a4ea3
  2. 01 Oct, 2014 14 commits