1. 22 Sep, 2017 2 commits
    • Waiman Long's avatar
      cgroup: Reinit cgroup_taskset structure before cgroup_migrate_execute() returns · c4fa6c43
      Waiman Long authored
      The cgroup_taskset structure within the larger cgroup_mgctx structure
      is supposed to be used once and then discarded. That is not really the
      case in the hotplug code path:
      
      cpuset_hotplug_workfn()
       - cgroup_transfer_tasks()
         - cgroup_migrate()
           - cgroup_migrate_add_task()
           - cgroup_migrate_execute()
      
      In this case, the cgroup_migrate() function is called multiple time
      with the same cgroup_mgctx structure to transfer the tasks from
      one cgroup to another one-by-one. The second time cgroup_migrate()
      is called, the cgroup_taskset will be in an incorrect state and so
      may cause the system to panic. For example,
      
        [  150.888410] Faulting instruction address: 0xc0000000001db648
        [  150.888414] Oops: Kernel access of bad area, sig: 11 [#1]
        [  150.888417] SMP NR_CPUS=2048
        [  150.888417] NUMA
        [  150.888419] pSeries
          :
        [  150.888545] NIP [c0000000001db648] cpuset_can_attach+0x58/0x1b0
        [  150.888548] LR [c0000000001db638] cpuset_can_attach+0x48/0x1b0
        [  150.888551] Call Trace:
        [  150.888554] [c0000005f65cb940] [c0000000001db638] cpuset_can_attach+0x48/0x1b 0 (unreliable)
        [  150.888559] [c0000005f65cb9a0] [c0000000001cff04] cgroup_migrate_execute+0xc4/0x4b0
        [  150.888563] [c0000005f65cba20] [c0000000001d7d14] cgroup_transfer_tasks+0x1d4/0x370
        [  150.888568] [c0000005f65cbb70] [c0000000001ddcb0] cpuset_hotplug_workfn+0x710/0x8f0
        [  150.888572] [c0000005f65cbc80] [c00000000012032c] process_one_work+0x1ac/0x4d0
        [  150.888576] [c0000005f65cbd20] [c0000000001206f8] worker_thread+0xa8/0x5b0
        [  150.888580] [c0000005f65cbdc0] [c0000000001293f8] kthread+0x168/0x1b0
        [  150.888584] [c0000005f65cbe30] [c00000000000b368] ret_from_kernel_thread+0x5c/0x74
      
      To allow reuse of the cgroup_mgctx structure, some fields in that
      structure are now re-initialized at the end of cgroup_migrate_execute()
      function call so that the structure can be reused again in a later
      iteration without causing problem.
      
      This bug was introduced in the commit e595cd70 ("group: track
      migration context in cgroup_mgctx") in 4.11. This commit moves the
      cgroup_taskset initialization out of cgroup_migrate(). The commit
      10467270fb3 ("cgroup: don't call migration methods if there are no
      tasks to migrate") helped, but did not completely resolve the problem.
      
      Fixes: e595cd70 ("group: track migration context in cgroup_mgctx")
      Signed-off-by: default avatarWaiman Long <longman@redhat.com>
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: stable@vger.kernel.org # v4.11+
      c4fa6c43
    • Linus Torvalds's avatar
      Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm · 6e80ecdd
      Linus Torvalds authored
      Pull libnvdimm fixes from Dan Williams:
       "A crash fix and corresponding regression test enabling for the crash
        scenario. The unit test for this crash is available in ndctl-v58.2.
      
        This branch has received a build success notification from the
        0day-kbuild robot over 148 configs. The fix is tagged for -stable /
        backport to 4.13"
      
      * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
        libnvdimm, namespace: fix btt claim class crash
        tools/testing/nvdimm: disable labels for nfit_test.1
      6e80ecdd
  2. 21 Sep, 2017 7 commits
  3. 20 Sep, 2017 10 commits
  4. 19 Sep, 2017 15 commits
  5. 18 Sep, 2017 6 commits