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  1. May 20, 2014
  2. May 17, 2014
    • Vlad Yasevich's avatar
      bonding: Fix stacked device detection in arp monitoring · 44a40855
      Vlad Yasevich authored
      
      Prior to commit fbd929f2
      	bonding: support QinQ for bond arp interval
      
      the arp monitoring code allowed for proper detection of devices
      stacked on top of vlans.  Since the above commit, the
      code can still detect a device stacked on top of single
      vlan, but not a device stacked on top of Q-in-Q configuration.
      The search will only set the inner vlan tag if the route
      device is the vlan device.  However, this is not always the
      case, as it is possible to extend the stacked configuration.
      
      With this patch it is possible to provision devices on
      top Q-in-Q vlan configuration that should be used as
      a source of ARP monitoring information.
      
      For example:
      ip link add link bond0 vlan10 type vlan proto 802.1q id 10
      ip link add link vlan10 vlan100 type vlan proto 802.1q id 100
      ip link add link vlan100 type macvlan
      
      Note:  This patch limites the number of stacked VLANs to 2,
      just like before.  The original, however had another issue
      in that if we had more then 2 levels of VLANs, we would end
      up generating incorrectly tagged traffic.  This is no longer
      possible.
      
      Fixes: fbd929f2 (bonding: support QinQ for bond arp interval)
      CC: Jay Vosburgh <j.vosburgh@gmail.com>
      CC: Veaceslav Falico <vfalico@redhat.com>
      CC: Andy Gospodarek <andy@greyhouse.net>
      CC: Ding Tianhong <dingtianhong@huawei.com>
      CC: Patric McHardy <kaber@trash.net>
      Signed-off-by: default avatarVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      44a40855
    • Vlad Yasevich's avatar
      macvlan: Fix lockdep warnings with stacked macvlan devices · c674ac30
      Vlad Yasevich authored
      
      Macvlan devices try to avoid stacking, but that's not always
      successfull or even desired.  As an example, the following
      configuration is perefectly legal and valid:
      
      eth0 <--- macvlan0 <---- vlan0.10 <--- macvlan1
      
      However, this configuration produces the following lockdep
      trace:
      [  115.620418] ======================================================
      [  115.620477] [ INFO: possible circular locking dependency detected ]
      [  115.620516] 3.15.0-rc1+ #24 Not tainted
      [  115.620540] -------------------------------------------------------
      [  115.620577] ip/1704 is trying to acquire lock:
      [  115.620604]  (&vlan_netdev_addr_lock_key/1){+.....}, at: [<ffffffff815df49c>] dev_uc_sync+0x3c/0x80
      [  115.620686]
      but task is already holding lock:
      [  115.620723]  (&macvlan_netdev_addr_lock_key){+.....}, at: [<ffffffff815da5be>] dev_set_rx_mode+0x1e/0x40
      [  115.620795]
      which lock already depends on the new lock.
      
      [  115.620853]
      the existing dependency chain (in reverse order) is:
      [  115.620894]
      -> #1 (&macvlan_netdev_addr_lock_key){+.....}:
      [  115.620935]        [<ffffffff810d57f2>] lock_acquire+0xa2/0x130
      [  115.620974]        [<ffffffff816f62e7>] _raw_spin_lock_nested+0x37/0x50
      [  115.621019]        [<ffffffffa07296c3>] vlan_dev_set_rx_mode+0x53/0x110 [8021q]
      [  115.621066]        [<ffffffff815da557>] __dev_set_rx_mode+0x57/0xa0
      [  115.621105]        [<ffffffff815da5c6>] dev_set_rx_mode+0x26/0x40
      [  115.621143]        [<ffffffff815da6be>] __dev_open+0xde/0x140
      [  115.621174]        [<ffffffff815da9ad>] __dev_change_flags+0x9d/0x170
      [  115.621174]        [<ffffffff815daaa9>] dev_change_flags+0x29/0x60
      [  115.621174]        [<ffffffff815e7f11>] do_setlink+0x321/0x9a0
      [  115.621174]        [<ffffffff815ea59f>] rtnl_newlink+0x51f/0x730
      [  115.621174]        [<ffffffff815e6e75>] rtnetlink_rcv_msg+0x95/0x250
      [  115.621174]        [<ffffffff81608b19>] netlink_rcv_skb+0xa9/0xc0
      [  115.621174]        [<ffffffff815e6dca>] rtnetlink_rcv+0x2a/0x40
      [  115.621174]        [<ffffffff81608150>] netlink_unicast+0xf0/0x1c0
      [  115.621174]        [<ffffffff8160851f>] netlink_sendmsg+0x2ff/0x740
      [  115.621174]        [<ffffffff815bc9db>] sock_sendmsg+0x8b/0xc0
      [  115.621174]        [<ffffffff815bd4b9>] ___sys_sendmsg+0x369/0x380
      [  115.621174]        [<ffffffff815bdbb2>] __sys_sendmsg+0x42/0x80
      [  115.621174]        [<ffffffff815bdc02>] SyS_sendmsg+0x12/0x20
      [  115.621174]        [<ffffffff816ffd69>] system_call_fastpath+0x16/0x1b
      [  115.621174]
      -> #0 (&vlan_netdev_addr_lock_key/1){+.....}:
      [  115.621174]        [<ffffffff810d4d43>] __lock_acquire+0x1773/0x1a60
      [  115.621174]        [<ffffffff810d57f2>] lock_acquire+0xa2/0x130
      [  115.621174]        [<ffffffff816f62e7>] _raw_spin_lock_nested+0x37/0x50
      [  115.621174]        [<ffffffff815df49c>] dev_uc_sync+0x3c/0x80
      [  115.621174]        [<ffffffffa0696d2a>] macvlan_set_mac_lists+0xca/0x110 [macvlan]
      [  115.621174]        [<ffffffff815da557>] __dev_set_rx_mode+0x57/0xa0
      [  115.621174]        [<ffffffff815da5c6>] dev_set_rx_mode+0x26/0x40
      [  115.621174]        [<ffffffff815da6be>] __dev_open+0xde/0x140
      [  115.621174]        [<ffffffff815da9ad>] __dev_change_flags+0x9d/0x170
      [  115.621174]        [<ffffffff815daaa9>] dev_change_flags+0x29/0x60
      [  115.621174]        [<ffffffff815e7f11>] do_setlink+0x321/0x9a0
      [  115.621174]        [<ffffffff815ea59f>] rtnl_newlink+0x51f/0x730
      [  115.621174]        [<ffffffff815e6e75>] rtnetlink_rcv_msg+0x95/0x250
      [  115.621174]        [<ffffffff81608b19>] netlink_rcv_skb+0xa9/0xc0
      [  115.621174]        [<ffffffff815e6dca>] rtnetlink_rcv+0x2a/0x40
      [  115.621174]        [<ffffffff81608150>] netlink_unicast+0xf0/0x1c0
      [  115.621174]        [<ffffffff8160851f>] netlink_sendmsg+0x2ff/0x740
      [  115.621174]        [<ffffffff815bc9db>] sock_sendmsg+0x8b/0xc0
      [  115.621174]        [<ffffffff815bd4b9>] ___sys_sendmsg+0x369/0x380
      [  115.621174]        [<ffffffff815bdbb2>] __sys_sendmsg+0x42/0x80
      [  115.621174]        [<ffffffff815bdc02>] SyS_sendmsg+0x12/0x20
      [  115.621174]        [<ffffffff816ffd69>] system_call_fastpath+0x16/0x1b
      [  115.621174]
      other info that might help us debug this:
      
      [  115.621174]  Possible unsafe locking scenario:
      
      [  115.621174]        CPU0                    CPU1
      [  115.621174]        ----                    ----
      [  115.621174]   lock(&macvlan_netdev_addr_lock_key);
      [  115.621174]                                lock(&vlan_netdev_addr_lock_key/1);
      [  115.621174]                                lock(&macvlan_netdev_addr_lock_key);
      [  115.621174]   lock(&vlan_netdev_addr_lock_key/1);
      [  115.621174]
       *** DEADLOCK ***
      
      [  115.621174] 2 locks held by ip/1704:
      [  115.621174]  #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff815e6dbb>] rtnetlink_rcv+0x1b/0x40
      [  115.621174]  #1:  (&macvlan_netdev_addr_lock_key){+.....}, at: [<ffffffff815da5be>] dev_set_rx_mode+0x1e/0x40
      [  115.621174]
      stack backtrace:
      [  115.621174] CPU: 3 PID: 1704 Comm: ip Not tainted 3.15.0-rc1+ #24
      [  115.621174] Hardware name: Hewlett-Packard HP xw8400 Workstation/0A08h, BIOS 786D5 v02.38 10/25/2010
      [  115.621174]  ffffffff82339ae0 ffff880465f79568 ffffffff816ee20c ffffffff82339ae0
      [  115.621174]  ffff880465f795a8 ffffffff816e9e1b ffff880465f79600 ffff880465b019c8
      [  115.621174]  0000000000000001 0000000000000002 ffff880465b019c8 ffff880465b01230
      [  115.621174] Call Trace:
      [  115.621174]  [<ffffffff816ee20c>] dump_stack+0x4d/0x66
      [  115.621174]  [<ffffffff816e9e1b>] print_circular_bug+0x200/0x20e
      [  115.621174]  [<ffffffff810d4d43>] __lock_acquire+0x1773/0x1a60
      [  115.621174]  [<ffffffff810d3172>] ? trace_hardirqs_on_caller+0xb2/0x1d0
      [  115.621174]  [<ffffffff810d57f2>] lock_acquire+0xa2/0x130
      [  115.621174]  [<ffffffff815df49c>] ? dev_uc_sync+0x3c/0x80
      [  115.621174]  [<ffffffff816f62e7>] _raw_spin_lock_nested+0x37/0x50
      [  115.621174]  [<ffffffff815df49c>] ? dev_uc_sync+0x3c/0x80
      [  115.621174]  [<ffffffff815df49c>] dev_uc_sync+0x3c/0x80
      [  115.621174]  [<ffffffffa0696d2a>] macvlan_set_mac_lists+0xca/0x110 [macvlan]
      [  115.621174]  [<ffffffff815da557>] __dev_set_rx_mode+0x57/0xa0
      [  115.621174]  [<ffffffff815da5c6>] dev_set_rx_mode+0x26/0x40
      [  115.621174]  [<ffffffff815da6be>] __dev_open+0xde/0x140
      [  115.621174]  [<ffffffff815da9ad>] __dev_change_flags+0x9d/0x170
      [  115.621174]  [<ffffffff815daaa9>] dev_change_flags+0x29/0x60
      [  115.621174]  [<ffffffff811e1db1>] ? mem_cgroup_bad_page_check+0x21/0x30
      [  115.621174]  [<ffffffff815e7f11>] do_setlink+0x321/0x9a0
      [  115.621174]  [<ffffffff810d394c>] ? __lock_acquire+0x37c/0x1a60
      [  115.621174]  [<ffffffff815ea59f>] rtnl_newlink+0x51f/0x730
      [  115.621174]  [<ffffffff815ea169>] ? rtnl_newlink+0xe9/0x730
      [  115.621174]  [<ffffffff815e6e75>] rtnetlink_rcv_msg+0x95/0x250
      [  115.621174]  [<ffffffff810d329d>] ? trace_hardirqs_on+0xd/0x10
      [  115.621174]  [<ffffffff815e6dbb>] ? rtnetlink_rcv+0x1b/0x40
      [  115.621174]  [<ffffffff815e6de0>] ? rtnetlink_rcv+0x40/0x40
      [  115.621174]  [<ffffffff81608b19>] netlink_rcv_skb+0xa9/0xc0
      [  115.621174]  [<ffffffff815e6dca>] rtnetlink_rcv+0x2a/0x40
      [  115.621174]  [<ffffffff81608150>] netlink_unicast+0xf0/0x1c0
      [  115.621174]  [<ffffffff8160851f>] netlink_sendmsg+0x2ff/0x740
      [  115.621174]  [<ffffffff815bc9db>] sock_sendmsg+0x8b/0xc0
      [  115.621174]  [<ffffffff8119d4af>] ? might_fault+0x5f/0xb0
      [  115.621174]  [<ffffffff8119d4f8>] ? might_fault+0xa8/0xb0
      [  115.621174]  [<ffffffff8119d4af>] ? might_fault+0x5f/0xb0
      [  115.621174]  [<ffffffff815cb51e>] ? verify_iovec+0x5e/0xe0
      [  115.621174]  [<ffffffff815bd4b9>] ___sys_sendmsg+0x369/0x380
      [  115.621174]  [<ffffffff816faa0d>] ? __do_page_fault+0x11d/0x570
      [  115.621174]  [<ffffffff810cfe9f>] ? up_read+0x1f/0x40
      [  115.621174]  [<ffffffff816fab04>] ? __do_page_fault+0x214/0x570
      [  115.621174]  [<ffffffff8120a10b>] ? mntput_no_expire+0x6b/0x1c0
      [  115.621174]  [<ffffffff8120a0b7>] ? mntput_no_expire+0x17/0x1c0
      [  115.621174]  [<ffffffff8120a284>] ? mntput+0x24/0x40
      [  115.621174]  [<ffffffff815bdbb2>] __sys_sendmsg+0x42/0x80
      [  115.621174]  [<ffffffff815bdc02>] SyS_sendmsg+0x12/0x20
      [  115.621174]  [<ffffffff816ffd69>] system_call_fastpath+0x16/0x1b
      
      Fix this by correctly providing macvlan lockdep class.
      
      Signed-off-by: default avatarVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c674ac30
    • Vlad Yasevich's avatar
      vlan: Fix lockdep warning with stacked vlan devices. · d38569ab
      Vlad Yasevich authored
      
      This reverts commit dc8eaaa0.
      	vlan: Fix lockdep warning when vlan dev handle notification
      
      Instead we use the new new API to find the lock subclass of
      our vlan device.  This way we can support configurations where
      vlans are interspersed with other devices:
        bond -> vlan -> macvlan -> vlan
      
      Signed-off-by: default avatarVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d38569ab
    • Vlad Yasevich's avatar
      net: Allow for more then a single subclass for netif_addr_lock · 25175ba5
      Vlad Yasevich authored
      
      Currently netif_addr_lock_nested assumes that there can be only
      a single nesting level between 2 devices.  However, if we
      have multiple devices of the same type stacked, this fails.
      For example:
       eth0 <-- vlan0.10 <-- vlan0.10.20
      
      A more complicated configuration may stack more then one type of
      device in different order.
      Ex:
        eth0 <-- vlan0.10 <-- macvlan0 <-- vlan1.10.20 <-- macvlan1
      
      This patch adds an ndo_* function that allows each stackable
      device to report its nesting level.  If the device doesn't
      provide this function default subclass of 1 is used.
      
      Signed-off-by: default avatarVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      25175ba5
    • Vlad Yasevich's avatar
      net: Find the nesting level of a given device by type. · 4085ebe8
      Vlad Yasevich authored
      
      Multiple devices in the kernel can be stacked/nested and they
      need to know their nesting level for the purposes of lockdep.
      This patch provides a generic function that determines a nesting
      level of a particular device by its type (ex: vlan, macvlan, etc).
      We only care about nesting of the same type of devices.
      
      For example:
        eth0 <- vlan0.10 <- macvlan0 <- vlan1.20
      
      The nesting level of vlan1.20 would be 1, since there is another vlan
      in the stack under it.
      
      Signed-off-by: default avatarVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      4085ebe8
  3. May 16, 2014
  4. May 15, 2014
  5. May 14, 2014
    • Hannes Frederic Sowa's avatar
      net: avoid dependency of net_get_random_once on nop patching · 3d440522
      Hannes Frederic Sowa authored
      
      net_get_random_once depends on the static keys infrastructure to patch up
      the branch to the slow path during boot. This was realized by abusing the
      static keys api and defining a new initializer to not enable the call
      site while still indicating that the branch point should get patched
      up. This was needed to have the fast path considered likely by gcc.
      
      The static key initialization during boot up normally walks through all
      the registered keys and either patches in ideal nops or enables the jump
      site but omitted that step on x86 if ideal nops where already placed at
      static_key branch points. Thus net_get_random_once branches not always
      became active.
      
      This patch switches net_get_random_once to the ordinary static_key
      api and thus places the kernel fast path in the - by gcc considered -
      unlikely path.  Microbenchmarks on Intel and AMD x86-64 showed that
      the unlikely path actually beats the likely path in terms of cycle cost
      and that different nop patterns did not make much difference, thus this
      switch should not be noticeable.
      
      Fixes: a48e4292 ("net: introduce new macro net_get_random_once")
      Reported-by: default avatarTuomas Räsänen <tuomasjjrasanen@tjjr.fi>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      3d440522
  6. May 13, 2014
  7. May 09, 2014
  8. May 07, 2014
  9. May 05, 2014
  10. May 04, 2014
  11. May 03, 2014
    • Marc Zyngier's avatar
      arm64: fixmap: fix missing sub-page offset for earlyprintk · f774b7d1
      Marc Zyngier authored
      
      Commit d57c33c5 (add generic fixmap.h) added (among other
      similar things) set_fixmap_io to deal with early ioremap of devices.
      
      More recently, commit bf4b558e (arm64: add early_ioremap support)
      converted the arm64 earlyprintk to use set_fixmap_io. A side effect of
      this conversion is that my virtual machines have stopped booting when
      I pass "earlyprintk=uart8250-8bit,0x3f8" to the guest kernel.
      
      Turns out that the new earlyprintk code doesn't care at all about
      sub-page offsets, and just assumes that the earlyprintk device will
      be page-aligned. Obviously, that doesn't play well with the above example.
      
      Further investigation shows that set_fixmap_io uses __set_fixmap instead
      of __set_fixmap_offset. A fix is to introduce a set_fixmap_offset_io that
      uses the latter, and to remove the superflous call to fix_to_virt
      (which only returns the value that set_fixmap_io has already given us).
      
      With this applied, my VMs are back in business. Tested on a Cortex-A57
      platform with kvmtool as platform emulation.
      
      Cc: Will Deacon <will.deacon@arm.com>
      Acked-by: default avatarMark Salter <msalter@redhat.com>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      f774b7d1
  12. May 01, 2014
  13. Apr 28, 2014
    • Steven Rostedt (Red Hat)'s avatar
      ftrace/module: Hardcode ftrace_module_init() call into load_module() · a949ae56
      Steven Rostedt (Red Hat) authored
      A race exists between module loading and enabling of function tracer.
      
      	CPU 1				CPU 2
      	-----				-----
        load_module()
         module->state = MODULE_STATE_COMING
      
      				register_ftrace_function()
      				 mutex_lock(&ftrace_lock);
      				 ftrace_startup()
      				  update_ftrace_function();
      				   ftrace_arch_code_modify_prepare()
      				    set_all_module_text_rw();
      				   <enables-ftrace>
      				    ftrace_arch_code_modify_post_process()
      				     set_all_module_text_ro();
      
      				[ here all module text is set to RO,
      				  including the module that is
      				  loading!! ]
      
         blocking_notifier_call_chain(MODULE_STATE_COMING);
          ftrace_init_module()
      
           [ tries to modify code, but it's RO, and fails!
             ftrace_bug() is called]
      
      When this race happens, ftrace_bug() will produces a nasty warning and
      all of the function tracing features will be disabled until reboot.
      
      The simple solution is to treate module load the same way the core
      kernel is treated at boot. To hardcode the ftrace function modification
      of converting calls to mcount into nops. This is done in init/main.c
      there's no reason it could not be done in load_module(). This gives
      a better control of the changes and doesn't tie the state of the
      module to its notifiers as much. Ftrace is special, it needs to be
      treated as such.
      
      The reason this would work, is that the ftrace_module_init() would be
      called while the module is in MODULE_STATE_UNFORMED, which is ignored
      by the set_all_module_text_ro() call.
      
      Link: http://lkml.kernel.org/r/1395637826-3312-1-git-send-email-indou.takao@jp.fujitsu.com
      
      
      
      Reported-by: default avatarTakao Indoh <indou.takao@jp.fujitsu.com>
      Acked-by: default avatarRusty Russell <rusty@rustcorp.com.au>
      Cc: stable@vger.kernel.org # 2.6.38+
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      a949ae56
    • Thomas Gleixner's avatar
      genirq: x86: Ensure that dynamic irq allocation does not conflict · 62a08ae2
      Thomas Gleixner authored
      
      On x86 the allocation of irq descriptors may allocate interrupts which
      are in the range of the GSI interrupts. That's wrong as those
      interrupts are hardwired and we don't have the irq domain translation
      like PPC. So one of these interrupts can be hooked up later to one of
      the devices which are hard wired to it and the io_apic init code for
      that particular interrupt line happily reuses that descriptor with a
      completely different configuration so hell breaks lose.
      
      Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs,
      except for a few usage sites which have not yet blown up in our face
      for whatever reason. But for drivers which need an irq range, like the
      GPIO drivers, we have no limit in place and we don't want to expose
      such a detail to a driver.
      
      To cure this introduce a function which an architecture can implement
      to impose a lower bound on the dynamic interrupt allocations.
      
      Implement it for x86 and set the lower bound to nr_gsi_irqs, which is
      the end of the hardwired interrupt space, so all dynamic allocations
      happen above.
      
      That not only allows the GPIO driver to work sanely, it also protects
      the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and
      htirq code. They need to be cleaned up as well, but that's a separate
      issue.
      
      Reported-by: default avatarJin Yao <yao.jin@linux.intel.com>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
      Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Grant Likely <grant.likely@linaro.org>
      Cc: H. Peter Anvin <hpa@linux.intel.com>
      Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
      Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
      Cc: Krogerus Heikki <heikki.krogerus@intel.com>
      Cc: Linus Walleij <linus.walleij@linaro.org>
      Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1404241617360.28206@ionos.tec.linutronix.de
      
      
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      62a08ae2
    • Randy Dunlap's avatar
      linux/interrupt.h: fix new kernel-doc warnings · def5f127
      Randy Dunlap authored
      
      Fix new kernel-doc warnings in <linux/interrupt.h>:
      
      Warning(include/linux/interrupt.h:219): No description found for parameter 'cpumask'
      Warning(include/linux/interrupt.h:219): Excess function parameter 'mask' description in 'irq_set_affinity'
      Warning(include/linux/interrupt.h:236): No description found for parameter 'cpumask'
      Warning(include/linux/interrupt.h:236): Excess function parameter 'mask' description in 'irq_force_affinity'
      
      Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
      Link: http://lkml.kernel.org/r/535DD2FD.7030804@infradead.org
      
      
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      def5f127
    • Will Deacon's avatar
      word-at-a-time: avoid undefined behaviour in zero_bytemask macro · ec6931b2
      Will Deacon authored
      
      The asm-generic, big-endian version of zero_bytemask creates a mask of
      bytes preceding the first zero-byte by left shifting ~0ul based on the
      position of the first zero byte.
      
      Unfortunately, if the first (top) byte is zero, the output of
      prep_zero_mask has only the top bit set, resulting in undefined C
      behaviour as we shift left by an amount equal to the width of the type.
      As it happens, GCC doesn't manage to spot this through the call to fls(),
      but the issue remains if architectures choose to implement their shift
      instructions differently.
      
      An example would be arch/arm/ (AArch32), where LSL Rd, Rn, #32 results
      in Rd == 0x0, whilst on arch/arm64 (AArch64) LSL Xd, Xn, #64 results in
      Xd == Xn.
      
      Rather than check explicitly for the problematic shift, this patch adds
      an extra shift by 1, replacing fls with __fls. Since zero_bytemask is
      never called with a zero argument (has_zero() is used to check the data
      first), we don't need to worry about calling __fls(0), which is
      undefined.
      
      Cc: <stable@vger.kernel.org>
      Cc: Victor Kamensky <victor.kamensky@linaro.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ec6931b2
  14. Apr 25, 2014
    • Manfred Schlaegl's avatar
      tty: Fix race condition between __tty_buffer_request_room and flush_to_ldisc · 6a20dbd6
      Manfred Schlaegl authored
      
      The race was introduced while development of linux-3.11 by
      e8437d7e and
      e9975fde.
      Originally it was found and reproduced on linux-3.12.15 and
      linux-3.12.15-rt25, by sending 500 byte blocks with 115kbaud to the
      target uart in a loop with 100 milliseconds delay.
      
      In short:
       1. The consumer flush_to_ldisc is on to remove the head tty_buffer.
       2. The producer adds a number of bytes, so that a new tty_buffer must
      	be allocated and added by __tty_buffer_request_room.
       3. The consumer removes the head tty_buffer element, without handling
      	newly committed data.
      
      Detailed example:
       * Initial buffer:
         * Head, Tail -> 0: used=250; commit=250; read=240; next=NULL
       * Consumer: ''flush_to_ldisc''
         * consumed 10 Byte
         * buffer:
           * Head, Tail -> 0: used=250; commit=250; read=250; next=NULL
      {{{
      		count = head->commit - head->read;	// count = 0
      		if (!count) {				// enter
      			// INTERRUPTED BY PRODUCER ->
      			if (head->next == NULL)
      				break;
      			buf->head = head->next;
      			tty_buffer_free(port, head);
      			continue;
      		}
      }}}
       * Producer: tty_insert_flip_... 10 bytes + tty_flip_buffer_push
         * buffer:
           * Head, Tail -> 0: used=250; commit=250; read=250; next=NULL
         * added 6 bytes: head-element filled to maximum.
           * buffer:
             * Head, Tail -> 0: used=256; commit=250; read=250; next=NULL
         * added 4 bytes: __tty_buffer_request_room is called
           * buffer:
             * Head -> 0: used=256; commit=256; read=250; next=1
             * Tail -> 1: used=4; commit=0; read=250 next=NULL
         * push (tty_flip_buffer_push)
           * buffer:
             * Head -> 0: used=256; commit=256; read=250; next=1
             * Tail -> 1: used=4; commit=4; read=250 next=NULL
       * Consumer
      {{{
      		count = head->commit - head->read;
      		if (!count) {
      			// INTERRUPTED BY PRODUCER <-
      			if (head->next == NULL)		// -> no break
      				break;
      			buf->head = head->next;
      			tty_buffer_free(port, head);
      			// ERROR: tty_buffer head freed -> 6 bytes lost
      			continue;
      		}
      }}}
      
      This patch reintroduces a spin_lock to protect this case. Perhaps later
      a lock-less solution could be found.
      
      Signed-off-by: default avatarManfred Schlaegl <manfred.schlaegl@gmx.at>
      Cc: stable <stable@vger.kernel.org> # 3.11
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6a20dbd6
  15. Apr 24, 2014
  16. Apr 23, 2014
  17. Apr 22, 2014
    • Andrew Lutomirski's avatar
      net: Fix ns_capable check in sock_diag_put_filterinfo · 78541c1d
      Andrew Lutomirski authored
      
      The caller needs capabilities on the namespace being queried, not on
      their own namespace.  This is a security bug, although it likely has
      only a minor impact.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
      Acked-by: default avatarNicolas Dichtel <nicolas.dichtel@6wind.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      78541c1d
    • Jeff Layton's avatar
      locks: rename file-private locks to "open file description locks" · 0d3f7a2d
      Jeff Layton authored
      
      File-private locks have been merged into Linux for v3.15, and *now*
      people are commenting that the name and macro definitions for the new
      file-private locks suck.
      
      ...and I can't even disagree. The names and command macros do suck.
      
      We're going to have to live with these for a long time, so it's
      important that we be happy with the names before we're stuck with them.
      The consensus on the lists so far is that they should be rechristened as
      "open file description locks".
      
      The name isn't a big deal for the kernel, but the command macros are not
      visually distinct enough from the traditional POSIX lock macros. The
      glibc and documentation folks are recommending that we change them to
      look like F_OFD_{GETLK|SETLK|SETLKW}. That lessens the chance that a
      programmer will typo one of the commands wrong, and also makes it easier
      to spot this difference when reading code.
      
      This patch makes the following changes that I think are necessary before
      v3.15 ships:
      
      1) rename the command macros to their new names. These end up in the uapi
         headers and so are part of the external-facing API. It turns out that
         glibc doesn't actually use the fcntl.h uapi header, but it's hard to
         be sure that something else won't. Changing it now is safest.
      
      2) make the the /proc/locks output display these as type "OFDLCK"
      
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Carlos O'Donell <carlos@redhat.com>
      Cc: Stefan Metzmacher <metze@samba.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Frank Filz <ffilzlnx@mindspring.com>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
      0d3f7a2d
  18. Apr 20, 2014
    • Hans de Goede's avatar
      Input: Add INPUT_PROP_TOPBUTTONPAD device property · f37c0134
      Hans de Goede authored
      
      On some newer laptops with a trackpoint the physical buttons for the
      trackpoint have been removed to allow for a larger touchpad. On these
      laptops the buttonpad has clearly marked areas on the top which are to be
      used as trackpad buttons.
      
      Users of the event device-node need to know about this, so that they can
      properly interpret BTN_LEFT events as being a left / right / middle click
      depending on where on the button pad the clicking finger is.
      
      This commits adds a INPUT_PROP_TOPBUTTONPAD device property which drivers
      for such buttonpads will use to signal to the user that this buttonpad not
      only has the normal bottom button area, but also a top button area.
      
      Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
      Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      f37c0134
    • Hans de Goede's avatar
      Input: serio - add firmware_id sysfs attribute · 0456c66f
      Hans de Goede authored
      
      serio devices exposed via platform firmware interfaces such as ACPI may
      provide additional identifying information of use to userspace.
      
      We don't associate the serio devices with the firmware device (we don't
      set it as parent), so there's no way for userspace to make use of this
      information.
      
      We cannot change the parent for serio devices instantiated though a
      firmware interface as that would break suspend / resume ordering.
      
      Therefore this patch adds a new firmware_id sysfs attribute so that
      userspace can get a string from there with any additional identifying
      information the firmware interface may provide.
      
      Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
      Acked-by: default avatarPeter Hutterer <peter.hutterer@who-t.net>
      Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      0456c66f
  19. Apr 19, 2014
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