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  1. May 14, 2021
  2. Mar 17, 2021
    • Xie He's avatar
      net: lapbether: Remove netif_start_queue / netif_stop_queue · 6342ccdf
      Xie He authored
      
      commit f7d9d485 upstream.
      
      For the devices in this driver, the default qdisc is "noqueue",
      because their "tx_queue_len" is 0.
      
      In function "__dev_queue_xmit" in "net/core/dev.c", devices with the
      "noqueue" qdisc are specially handled. Packets are transmitted without
      being queued after a "dev->flags & IFF_UP" check. However, it's possible
      that even if this check succeeds, "ops->ndo_stop" may still have already
      been called. This is because in "__dev_close_many", "ops->ndo_stop" is
      called before clearing the "IFF_UP" flag.
      
      If we call "netif_stop_queue" in "ops->ndo_stop", then it's possible in
      "__dev_queue_xmit", it sees the "IFF_UP" flag is present, and then it
      checks "netif_xmit_stopped" and finds that the queue is already stopped.
      In this case, it will complain that:
      "Virtual device ... asks to queue packet!"
      
      To prevent "__dev_queue_xmit" from generating this complaint, we should
      not call "netif_stop_queue" in "ops->ndo_stop".
      
      We also don't need to call "netif_start_queue" in "ops->ndo_open",
      because after a netdev is allocated and registered, the
      "__QUEUE_STATE_DRV_XOFF" flag is initially not set, so there is no need
      to call "netif_start_queue" to clear it.
      
      Fixes: 1da177e4 ("Linux-2.6.12-rc2")
      Signed-off-by: default avatarXie He <xie.he.0141@gmail.com>
      Acked-by: default avatarMartin Schiller <ms@dev.tdt.de>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6342ccdf
  3. Sep 17, 2020
    • Xie He's avatar
      drivers/net/wan/lapbether: Make skb->protocol consistent with the header · 83f9a9c8
      Xie He authored
      
      This driver is a virtual driver stacked on top of Ethernet interfaces.
      
      When this driver transmits data on the Ethernet device, the skb->protocol
      setting is inconsistent with the Ethernet header prepended to the skb.
      
      This causes a user listening on the Ethernet interface with an AF_PACKET
      socket, to see different sll_protocol values for incoming and outgoing
      frames, because incoming frames would have this value set by parsing the
      Ethernet header.
      
      This patch changes the skb->protocol value for outgoing Ethernet frames,
      making it consistent with the Ethernet header prepended. This makes a
      user listening on the Ethernet device with an AF_PACKET socket, to see
      the same sll_protocol value for incoming and outgoing frames.
      
      Cc: Martin Schiller <ms@dev.tdt.de>
      Signed-off-by: default avatarXie He <xie.he.0141@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      83f9a9c8
  4. Aug 26, 2020
    • Xie He's avatar
      drivers/net/wan/lapbether: Set network_header before transmitting · 91244d10
      Xie He authored
      
      Set the skb's network_header before it is passed to the underlying
      Ethernet device for transmission.
      
      This patch fixes the following issue:
      
      When we use this driver with AF_PACKET sockets, there would be error
      messages of:
         protocol 0805 is buggy, dev (Ethernet interface name)
      printed in the system "dmesg" log.
      
      This is because skbs passed down to the Ethernet device for transmission
      don't have their network_header properly set, and the dev_queue_xmit_nit
      function in net/core/dev.c complains about this.
      
      Reason of setting the network_header to this place (at the end of the
      Ethernet header, and at the beginning of the Ethernet payload):
      
      Because when this driver receives an skb from the Ethernet device, the
      network_header is also set at this place.
      
      Cc: Martin Schiller <ms@dev.tdt.de>
      Signed-off-by: default avatarXie He <xie.he.0141@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      91244d10
  5. Aug 24, 2020
  6. Aug 23, 2020
  7. Aug 07, 2020
    • Xie He's avatar
      drivers/net/wan/lapbether: Added needed_headroom and a skb->len check · c7ca03c2
      Xie He authored
      
      1. Added a skb->len check
      
      This driver expects upper layers to include a pseudo header of 1 byte
      when passing down a skb for transmission. This driver will read this
      1-byte header. This patch added a skb->len check before reading the
      header to make sure the header exists.
      
      2. Changed to use needed_headroom instead of hard_header_len to request
      necessary headroom to be allocated
      
      In net/packet/af_packet.c, the function packet_snd first reserves a
      headroom of length (dev->hard_header_len + dev->needed_headroom).
      Then if the socket is a SOCK_DGRAM socket, it calls dev_hard_header,
      which calls dev->header_ops->create, to create the link layer header.
      If the socket is a SOCK_RAW socket, it "un-reserves" a headroom of
      length (dev->hard_header_len), and assumes the user to provide the
      appropriate link layer header.
      
      So according to the logic of af_packet.c, dev->hard_header_len should
      be the length of the header that would be created by
      dev->header_ops->create.
      
      However, this driver doesn't provide dev->header_ops, so logically
      dev->hard_header_len should be 0.
      
      So we should use dev->needed_headroom instead of dev->hard_header_len
      to request necessary headroom to be allocated.
      
      This change fixes kernel panic when this driver is used with AF_PACKET
      SOCK_RAW sockets.
      
      Call stack when panic:
      
      [  168.399197] skbuff: skb_under_panic: text:ffffffff819d95fb len:20
      put:14 head:ffff8882704c0a00 data:ffff8882704c09fd tail:0x11 end:0xc0
      dev:veth0
      ...
      [  168.399255] Call Trace:
      [  168.399259]  skb_push.cold+0x14/0x24
      [  168.399262]  eth_header+0x2b/0xc0
      [  168.399267]  lapbeth_data_transmit+0x9a/0xb0 [lapbether]
      [  168.399275]  lapb_data_transmit+0x22/0x2c [lapb]
      [  168.399277]  lapb_transmit_buffer+0x71/0xb0 [lapb]
      [  168.399279]  lapb_kick+0xe3/0x1c0 [lapb]
      [  168.399281]  lapb_data_request+0x76/0xc0 [lapb]
      [  168.399283]  lapbeth_xmit+0x56/0x90 [lapbether]
      [  168.399286]  dev_hard_start_xmit+0x91/0x1f0
      [  168.399289]  ? irq_init_percpu_irqstack+0xc0/0x100
      [  168.399291]  __dev_queue_xmit+0x721/0x8e0
      [  168.399295]  ? packet_parse_headers.isra.0+0xd2/0x110
      [  168.399297]  dev_queue_xmit+0x10/0x20
      [  168.399298]  packet_sendmsg+0xbf0/0x19b0
      ......
      
      Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
      Cc: Martin Schiller <ms@dev.tdt.de>
      Cc: Brian Norris <briannorris@chromium.org>
      Signed-off-by: default avatarXie He <xie.he.0141@gmail.com>
      Acked-by: default avatarWillem de Bruijn <willemb@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c7ca03c2
  8. Jul 25, 2020
    • Xie He's avatar
      drivers/net/wan: lapb: Corrected the usage of skb_cow · 8754e137
      Xie He authored
      
      This patch fixed 2 issues with the usage of skb_cow in LAPB drivers
      "lapbether" and "hdlc_x25":
      
      1) After skb_cow fails, kfree_skb should be called to drop a reference
      to the skb. But in both drivers, kfree_skb is not called.
      
      2) skb_cow should be called before skb_push so that is can ensure the
      safety of skb_push. But in "lapbether", it is incorrectly called after
      skb_push.
      
      More details about these 2 issues:
      
      1) The behavior of calling kfree_skb on failure is also the behavior of
      netif_rx, which is called by this function with "return netif_rx(skb);".
      So this function should follow this behavior, too.
      
      2) In "lapbether", skb_cow is called after skb_push. This results in 2
      logical issues:
         a) skb_push is not protected by skb_cow;
         b) An extra headroom of 1 byte is ensured after skb_push. This extra
            headroom has no use in this function. It also has no use in the
            upper-layer function that this function passes the skb to
            (x25_lapb_receive_frame in net/x25/x25_dev.c).
      So logically skb_cow should instead be called before skb_push.
      
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: Martin Schiller <ms@dev.tdt.de>
      Signed-off-by: default avatarXie He <xie.he.0141@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8754e137
  9. Jul 06, 2020
    • Xie He's avatar
      drivers/net/wan/lapbether: Fixed the value of hard_header_len · 9dc829a1
      Xie He authored
      
      When this driver transmits data,
        first this driver will remove a pseudo header of 1 byte,
        then the lapb module will prepend the LAPB header of 2 or 3 bytes,
        then this driver will prepend a length field of 2 bytes,
        then the underlying Ethernet device will prepend its own header.
      
      So, the header length required should be:
        -1 + 3 + 2 + "the header length needed by the underlying device".
      
      This patch fixes kernel panic when this driver is used with AF_PACKET
      SOCK_DGRAM sockets.
      
      Signed-off-by: default avatarXie He <xie.he.0141@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      9dc829a1
  10. Jan 16, 2020
  11. May 24, 2019
  12. Nov 01, 2017
  13. Jun 07, 2017
    • David S. Miller's avatar
      net: Fix inconsistent teardown and release of private netdev state. · cf124db5
      David S. Miller authored
      
      Network devices can allocate reasources and private memory using
      netdev_ops->ndo_init().  However, the release of these resources
      can occur in one of two different places.
      
      Either netdev_ops->ndo_uninit() or netdev->destructor().
      
      The decision of which operation frees the resources depends upon
      whether it is necessary for all netdev refs to be released before it
      is safe to perform the freeing.
      
      netdev_ops->ndo_uninit() presumably can occur right after the
      NETDEV_UNREGISTER notifier completes and the unicast and multicast
      address lists are flushed.
      
      netdev->destructor(), on the other hand, does not run until the
      netdev references all go away.
      
      Further complicating the situation is that netdev->destructor()
      almost universally does also a free_netdev().
      
      This creates a problem for the logic in register_netdevice().
      Because all callers of register_netdevice() manage the freeing
      of the netdev, and invoke free_netdev(dev) if register_netdevice()
      fails.
      
      If netdev_ops->ndo_init() succeeds, but something else fails inside
      of register_netdevice(), it does call ndo_ops->ndo_uninit().  But
      it is not able to invoke netdev->destructor().
      
      This is because netdev->destructor() will do a free_netdev() and
      then the caller of register_netdevice() will do the same.
      
      However, this means that the resources that would normally be released
      by netdev->destructor() will not be.
      
      Over the years drivers have added local hacks to deal with this, by
      invoking their destructor parts by hand when register_netdevice()
      fails.
      
      Many drivers do not try to deal with this, and instead we have leaks.
      
      Let's close this hole by formalizing the distinction between what
      private things need to be freed up by netdev->destructor() and whether
      the driver needs unregister_netdevice() to perform the free_netdev().
      
      netdev->priv_destructor() performs all actions to free up the private
      resources that used to be freed by netdev->destructor(), except for
      free_netdev().
      
      netdev->needs_free_netdev is a boolean that indicates whether
      free_netdev() should be done at the end of unregister_netdevice().
      
      Now, register_netdevice() can sanely release all resources after
      ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit()
      and netdev->priv_destructor().
      
      And at the end of unregister_netdevice(), we invoke
      netdev->priv_destructor() and optionally call free_netdev().
      
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      cf124db5
  14. Dec 24, 2016
  15. Jun 18, 2015
  16. Jul 15, 2014
    • Tom Gundersen's avatar
      net: set name_assign_type in alloc_netdev() · c835a677
      Tom Gundersen authored
      
      Extend alloc_netdev{,_mq{,s}}() to take name_assign_type as argument, and convert
      all users to pass NET_NAME_UNKNOWN.
      
      Coccinelle patch:
      
      @@
      expression sizeof_priv, name, setup, txqs, rxqs, count;
      @@
      
      (
      -alloc_netdev_mqs(sizeof_priv, name, setup, txqs, rxqs)
      +alloc_netdev_mqs(sizeof_priv, name, NET_NAME_UNKNOWN, setup, txqs, rxqs)
      |
      -alloc_netdev_mq(sizeof_priv, name, setup, count)
      +alloc_netdev_mq(sizeof_priv, name, NET_NAME_UNKNOWN, setup, count)
      |
      -alloc_netdev(sizeof_priv, name, setup)
      +alloc_netdev(sizeof_priv, name, NET_NAME_UNKNOWN, setup)
      )
      
      v9: move comments here from the wrong commit
      
      Signed-off-by: default avatarTom Gundersen <teg@jklm.no>
      Reviewed-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c835a677
  17. May 28, 2013
  18. Mar 28, 2012
  19. Sep 16, 2011
  20. Jun 27, 2011
  21. May 05, 2011
  22. Sep 06, 2010
  23. Apr 22, 2010
  24. Mar 30, 2010
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  25. Sep 01, 2009
  26. Jun 17, 2009
  27. Mar 22, 2009
  28. Mar 10, 2009
  29. Feb 27, 2009
  30. Feb 18, 2009
  31. Feb 01, 2009
  32. Nov 04, 2008
  33. May 04, 2008
  34. Mar 28, 2008
  35. Mar 25, 2008
  36. Oct 10, 2007
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