1. 14 1月, 2016 1 次提交
  2. 08 1月, 2016 1 次提交
  3. 06 1月, 2016 4 次提交
  4. 30 12月, 2015 1 次提交
    • H
      mm/vmstat: fix overflow in mod_zone_page_state() · 6cdb18ad
      Heiko Carstens 提交于
      mod_zone_page_state() takes a "delta" integer argument.  delta contains
      the number of pages that should be added or subtracted from a struct
      zone's vm_stat field.
      
      If a zone is larger than 8TB this will cause overflows.  E.g.  for a
      zone with a size slightly larger than 8TB the line
      
          mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
      
      in mm/page_alloc.c:free_area_init_core() will result in a negative
      result for the NR_ALLOC_BATCH entry within the zone's vm_stat, since 8TB
      contain 0x8xxxxxxx pages which will be sign extended to a negative
      value.
      
      Fix this by changing the delta argument to long type.
      
      This could fix an early boot problem seen on s390, where we have a 9TB
      system with only one node.  ZONE_DMA contains 2GB and ZONE_NORMAL the
      rest.  The system is trying to allocate a GFP_DMA page but ZONE_DMA is
      completely empty, so it tries to reclaim pages in an endless loop.
      
      This was seen on a heavily patched 3.10 kernel.  One possible
      explaination seem to be the overflows caused by mod_zone_page_state().
      Unfortunately I did not have the chance to verify that this patch
      actually fixes the problem, since I don't have access to the system
      right now.  However the overflow problem does exist anyway.
      
      Given the description that a system with slightly less than 8TB does
      work, this seems to be a candidate for the observed problem.
      Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Christoph Lameter <cl@linux.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6cdb18ad
  5. 29 12月, 2015 1 次提交
  6. 24 12月, 2015 1 次提交
    • B
      net: cdc_ncm: avoid changing RX/TX buffers on MTU changes · 1dfddff5
      Bjørn Mork 提交于
      NCM buffer sizes are negotiated with the device independently of
      the network device MTU.  The RX buffers are allocated by the
      usbnet framework based on the rx_urb_size value set by cdc_ncm. A
      single RX buffer can hold a number of MTU sized packets.
      
      The default usbnet change_mtu ndo only modifies rx_urb_size if it
      is equal to hard_mtu.  And the cdc_ncm driver will set rx_urb_size
      and hard_mtu independently of each other, based on dwNtbInMaxSize
      and dwNtbOutMaxSize respectively. It was therefore assumed that
      usbnet_change_mtu() would never touch rx_urb_size.  This failed to
      consider the case where dwNtbInMaxSize and dwNtbOutMaxSize happens
      to be equal.
      
      Fix by implementing an NCM specific change_mtu ndo, modifying the
      netdev MTU without touching the buffer size settings.
      Signed-off-by: NBjørn Mork <bjorn@mork.no>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1dfddff5
  7. 19 12月, 2015 1 次提交
  8. 14 12月, 2015 1 次提交
  9. 13 12月, 2015 2 次提交
  10. 12 12月, 2015 2 次提交
  11. 11 12月, 2015 1 次提交
  12. 10 12月, 2015 3 次提交
  13. 09 12月, 2015 3 次提交
  14. 08 12月, 2015 4 次提交
  15. 07 12月, 2015 2 次提交
  16. 05 12月, 2015 1 次提交
    • H
      rhashtable: Prevent spurious EBUSY errors on insertion · 3cf92222
      Herbert Xu 提交于
      Thomas and Phil observed that under stress rhashtable insertion
      sometimes failed with EBUSY, even though this error should only
      ever been seen when we're under attack and our hash chain length
      has grown to an unacceptable level, even after a rehash.
      
      It turns out that the logic for detecting whether there is an
      existing rehash is faulty.  In particular, when two threads both
      try to grow the same table at the same time, one of them may see
      the newly grown table and thus erroneously conclude that it had
      been rehashed.  This is what leads to the EBUSY error.
      
      This patch fixes this by remembering the current last table we
      used during insertion so that rhashtable_insert_rehash can detect
      when another thread has also done a resize/rehash.  When this is
      detected we will give up our resize/rehash and simply retry the
      insertion with the new table.
      Reported-by: NThomas Graf <tgraf@suug.ch>
      Reported-by: NPhil Sutter <phil@nwl.cc>
      Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
      Tested-by: NPhil Sutter <phil@nwl.cc>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      3cf92222
  17. 04 12月, 2015 1 次提交
  18. 03 12月, 2015 3 次提交
    • T
      cgroup: fix handling of multi-destination migration from subtree_control enabling · 1f7dd3e5
      Tejun Heo 提交于
      Consider the following v2 hierarchy.
      
        P0 (+memory) --- P1 (-memory) --- A
                                       \- B
             
      P0 has memory enabled in its subtree_control while P1 doesn't.  If
      both A and B contain processes, they would belong to the memory css of
      P1.  Now if memory is enabled on P1's subtree_control, memory csses
      should be created on both A and B and A's processes should be moved to
      the former and B's processes the latter.  IOW, enabling controllers
      can cause atomic migrations into different csses.
      
      The core cgroup migration logic has been updated accordingly but the
      controller migration methods haven't and still assume that all tasks
      migrate to a single target css; furthermore, the methods were fed the
      css in which subtree_control was updated which is the parent of the
      target csses.  pids controller depends on the migration methods to
      move charges and this made the controller attribute charges to the
      wrong csses often triggering the following warning by driving a
      counter negative.
      
       WARNING: CPU: 1 PID: 1 at kernel/cgroup_pids.c:97 pids_cancel.constprop.6+0x31/0x40()
       Modules linked in:
       CPU: 1 PID: 1 Comm: systemd Not tainted 4.4.0-rc1+ #29
       ...
        ffffffff81f65382 ffff88007c043b90 ffffffff81551ffc 0000000000000000
        ffff88007c043bc8 ffffffff810de202 ffff88007a752000 ffff88007a29ab00
        ffff88007c043c80 ffff88007a1d8400 0000000000000001 ffff88007c043bd8
       Call Trace:
        [<ffffffff81551ffc>] dump_stack+0x4e/0x82
        [<ffffffff810de202>] warn_slowpath_common+0x82/0xc0
        [<ffffffff810de2fa>] warn_slowpath_null+0x1a/0x20
        [<ffffffff8118e031>] pids_cancel.constprop.6+0x31/0x40
        [<ffffffff8118e0fd>] pids_can_attach+0x6d/0xf0
        [<ffffffff81188a4c>] cgroup_taskset_migrate+0x6c/0x330
        [<ffffffff81188e05>] cgroup_migrate+0xf5/0x190
        [<ffffffff81189016>] cgroup_attach_task+0x176/0x200
        [<ffffffff8118949d>] __cgroup_procs_write+0x2ad/0x460
        [<ffffffff81189684>] cgroup_procs_write+0x14/0x20
        [<ffffffff811854e5>] cgroup_file_write+0x35/0x1c0
        [<ffffffff812e26f1>] kernfs_fop_write+0x141/0x190
        [<ffffffff81265f88>] __vfs_write+0x28/0xe0
        [<ffffffff812666fc>] vfs_write+0xac/0x1a0
        [<ffffffff81267019>] SyS_write+0x49/0xb0
        [<ffffffff81bcef32>] entry_SYSCALL_64_fastpath+0x12/0x76
      
      This patch fixes the bug by removing @css parameter from the three
      migration methods, ->can_attach, ->cancel_attach() and ->attach() and
      updating cgroup_taskset iteration helpers also return the destination
      css in addition to the task being migrated.  All controllers are
      updated accordingly.
      
      * Controllers which don't care whether there are one or multiple
        target csses can be converted trivially.  cpu, io, freezer, perf,
        netclassid and netprio fall in this category.
      
      * cpuset's current implementation assumes that there's single source
        and destination and thus doesn't support v2 hierarchy already.  The
        only change made by this patchset is how that single destination css
        is obtained.
      
      * memory migration path already doesn't do anything on v2.  How the
        single destination css is obtained is updated and the prep stage of
        mem_cgroup_can_attach() is reordered to accomodate the change.
      
      * pids is the only controller which was affected by this bug.  It now
        correctly handles multi-destination migrations and no longer causes
        counter underflow from incorrect accounting.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Reported-and-tested-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
      Cc: Aleksa Sarai <cyphar@cyphar.com>
      1f7dd3e5
    • E
      ipv6: add complete rcu protection around np->opt · 45f6fad8
      Eric Dumazet 提交于
      This patch addresses multiple problems :
      
      UDP/RAW sendmsg() need to get a stable struct ipv6_txoptions
      while socket is not locked : Other threads can change np->opt
      concurrently. Dmitry posted a syzkaller
      (http://github.com/google/syzkaller) program desmonstrating
      use-after-free.
      
      Starting with TCP/DCCP lockless listeners, tcp_v6_syn_recv_sock()
      and dccp_v6_request_recv_sock() also need to use RCU protection
      to dereference np->opt once (before calling ipv6_dup_options())
      
      This patch adds full RCU protection to np->opt
      Reported-by: NDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      45f6fad8
    • S
      cpufreq: use last policy after online for drivers with ->setpolicy · 69030dd1
      Srinivas Pandruvada 提交于
      For cpufreq drivers which use setpolicy interface, after offline->online
      the policy is set to default. This can be reproduced by setting the
      default policy of intel_pstate or longrun to ondemand and then change to
      "performance". After offline and online, the setpolicy will be called with
      the policy=ondemand.
      
      For drivers using governors this condition is handled by storing
      last_governor, during offline and restoring during online. The same should
      be done for drivers using setpolicy interface. Storing last_policy during
      offline and restoring during online.
      Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
      Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
      69030dd1
  19. 02 12月, 2015 3 次提交
  20. 30 11月, 2015 3 次提交
  21. 29 11月, 2015 1 次提交