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SCSI Target Changes for VSCSI Target Driver #2

Merged
merged 1 commit into from
Mar 14, 2016
Merged

SCSI Target Changes for VSCSI Target Driver #2

merged 1 commit into from
Mar 14, 2016

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bgly
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@bgly bgly commented Mar 14, 2016

This push contains all the necessary changes that the VSCSI
Target Driver needs.

This push contains all the necessary changes that the VSCSI
Target Driver needs.
bgly pushed a commit that referenced this pull request Mar 14, 2016
SCSI Target Changes for VSCSI Target Driver
@bgly bgly merged commit 8d94e26 into master Mar 14, 2016
@bgly bgly deleted the for-next branch March 14, 2016 21:27
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit 3d5fe03 upstream.

We can end up allocating a new compression stream with GFP_KERNEL from
within the IO path, which may result is nested (recursive) IO
operations.  That can introduce problems if the IO path in question is a
reclaimer, holding some locks that will deadlock nested IOs.

Allocate streams and working memory using GFP_NOIO flag, forbidding
recursive IO and FS operations.

An example:

  inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
  git/20158 [HC0[0]:SC0[0]:HE1:SE1] takes:
   (jbd2_handle){+.+.?.}, at:  start_this_handle+0x4ca/0x555
  {IN-RECLAIM_FS-W} state was registered at:
     __lock_acquire+0x8da/0x117b
     lock_acquire+0x10c/0x1a7
     start_this_handle+0x52d/0x555
     jbd2__journal_start+0xb4/0x237
     __ext4_journal_start_sb+0x108/0x17e
     ext4_dirty_inode+0x32/0x61
     __mark_inode_dirty+0x16b/0x60c
     iput+0x11e/0x274
     __dentry_kill+0x148/0x1b8
     shrink_dentry_list+0x274/0x44a
     prune_dcache_sb+0x4a/0x55
     super_cache_scan+0xfc/0x176
     shrink_slab.part.14.constprop.25+0x2a2/0x4d3
     shrink_zone+0x74/0x140
     kswapd+0x6b7/0x930
     kthread+0x107/0x10f
     ret_from_fork+0x3f/0x70
  irq event stamp: 138297
  hardirqs last  enabled at (138297):  debug_check_no_locks_freed+0x113/0x12f
  hardirqs last disabled at (138296):  debug_check_no_locks_freed+0x33/0x12f
  softirqs last  enabled at (137818):  __do_softirq+0x2d3/0x3e9
  softirqs last disabled at (137813):  irq_exit+0x41/0x95

               other info that might help us debug this:
   Possible unsafe locking scenario:
         CPU0
         ----
    lock(jbd2_handle);
    <Interrupt>
      lock(jbd2_handle);

                *** DEADLOCK ***
  5 locks held by git/20158:
   #0:  (sb_writers#7){.+.+.+}, at: [<ffffffff81155411>] mnt_want_write+0x24/0x4b
   #1:  (&type->i_mutex_dir_key#2/1){+.+.+.}, at: [<ffffffff81145087>] lock_rename+0xd9/0xe3
   #2:  (&sb->s_type->i_mutex_key#11){+.+.+.}, at: [<ffffffff8114f8e2>] lock_two_nondirectories+0x3f/0x6b
   #3:  (&sb->s_type->i_mutex_key#11/4){+.+.+.}, at: [<ffffffff8114f909>] lock_two_nondirectories+0x66/0x6b
   #4:  (jbd2_handle){+.+.?.}, at: [<ffffffff811e31db>] start_this_handle+0x4ca/0x555

               stack backtrace:
  CPU: 2 PID: 20158 Comm: git Not tainted 4.1.0-rc7-next-20150615-dbg-00016-g8bdf555-dirty torvalds#211
  Call Trace:
    dump_stack+0x4c/0x6e
    mark_lock+0x384/0x56d
    mark_held_locks+0x5f/0x76
    lockdep_trace_alloc+0xb2/0xb5
    kmem_cache_alloc_trace+0x32/0x1e2
    zcomp_strm_alloc+0x25/0x73 [zram]
    zcomp_strm_multi_find+0xe7/0x173 [zram]
    zcomp_strm_find+0xc/0xe [zram]
    zram_bvec_rw+0x2ca/0x7e0 [zram]
    zram_make_request+0x1fa/0x301 [zram]
    generic_make_request+0x9c/0xdb
    submit_bio+0xf7/0x120
    ext4_io_submit+0x2e/0x43
    ext4_bio_write_page+0x1b7/0x300
    mpage_submit_page+0x60/0x77
    mpage_map_and_submit_buffers+0x10f/0x21d
    ext4_writepages+0xc8c/0xe1b
    do_writepages+0x23/0x2c
    __filemap_fdatawrite_range+0x84/0x8b
    filemap_flush+0x1c/0x1e
    ext4_alloc_da_blocks+0xb8/0x117
    ext4_rename+0x132/0x6dc
    ? mark_held_locks+0x5f/0x76
    ext4_rename2+0x29/0x2b
    vfs_rename+0x540/0x636
    SyS_renameat2+0x359/0x44d
    SyS_rename+0x1e/0x20
    entry_SYSCALL_64_fastpath+0x12/0x6f

[minchan@kernel.org: add stable mark]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Kyeongdon Kim <kyeongdon.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit ec183d2 upstream.

Fixes segmentation fault using, for instance:

  (gdb) run record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls
  Starting program: /home/acme/bin/perf record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls
  Missing separate debuginfos, use: dnf debuginfo-install glibc-2.22-7.fc23.x86_64
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/lib64/libthread_db.so.1".

 Program received signal SIGSEGV, Segmentation fault.
  0 x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410
  (gdb) bt
  #0  0x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410
  #1  0x00000000004b9fc5 in add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0)
      at util/parse-events.c:433
  #2  0x00000000004ba334 in add_tracepoint_event (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0)
      at util/parse-events.c:498
  #3  0x00000000004bb699 in parse_events_add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys=0x19b1370 "sched", event=0x19a5d00 "sched_switch", err=0x0, head_config=0x0)
      at util/parse-events.c:936
  #4  0x00000000004f6eda in parse_events_parse (_data=0x7fffffffb8b0, scanner=0x19a49d0) at util/parse-events.y:391
  #5  0x00000000004bc8e5 in parse_events__scanner (str=0x663ff2 "sched:sched_switch", data=0x7fffffffb8b0, start_token=258) at util/parse-events.c:1361
  #6  0x00000000004bca57 in parse_events (evlist=0x19a5220, str=0x663ff2 "sched:sched_switch", err=0x0) at util/parse-events.c:1401
  #7  0x0000000000518d5f in perf_evlist__can_select_event (evlist=0x19a3b90, str=0x663ff2 "sched:sched_switch") at util/record.c:253
  #8  0x0000000000553c42 in intel_pt_track_switches (evlist=0x19a3b90) at arch/x86/util/intel-pt.c:364
  #9  0x00000000005549d1 in intel_pt_recording_options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at arch/x86/util/intel-pt.c:664
  #10 0x000000000051e076 in auxtrace_record__options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at util/auxtrace.c:539
  #11 0x0000000000433368 in cmd_record (argc=1, argv=0x7fffffffde60, prefix=0x0) at builtin-record.c:1264
  #12 0x000000000049bec2 in run_builtin (p=0x8fa2a8 <commands+168>, argc=5, argv=0x7fffffffde60) at perf.c:390
  #13 0x000000000049c12a in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:451
  #14 0x000000000049c278 in run_argv (argcp=0x7fffffffdcbc, argv=0x7fffffffdcb0) at perf.c:495
  #15 0x000000000049c60a in main (argc=5, argv=0x7fffffffde60) at perf.c:618
(gdb)

Intel PT attempts to find the sched:sched_switch tracepoint but that seg
faults if tracefs is not readable, because the error reporting structure
is null, as errors are not reported when automatically adding
tracepoints.  Fix by checking before using.

Committer note:

This doesn't take place in a kernel that supports
perf_event_attr.context_switch, that is the default way that will be
used for tracking context switches, only in older kernels, like 4.2, in
a machine with Intel PT (e.g. Broadwell) for non-priviledged users.

Further info from a similar patch by Wang:

The error is in tracepoint_error: it assumes the 'e' parameter is valid.

However, there are many situation a parse_event() can be called without
parse_events_error. See result of

  $ grep 'parse_events(.*NULL)' ./tools/perf/ -r'

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Tong Zhang <ztong@vt.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 1965817 ("perf tools: Enhance parsing events tracepoint error output")
Link: http://lkml.kernel.org/r/1453809921-24596-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit 00cd29b upstream.

The starting node for a klist iteration is often passed in from
somewhere way above the klist infrastructure, meaning there's no
guarantee the node is still on the list.  We've seen this in SCSI where
we use bus_find_device() to iterate through a list of devices.  In the
face of heavy hotplug activity, the last device returned by
bus_find_device() can be removed before the next call.  This leads to

Dec  3 13:22:02 localhost kernel: WARNING: CPU: 2 PID: 28073 at include/linux/kref.h:47 klist_iter_init_node+0x3d/0x50()
Dec  3 13:22:02 localhost kernel: Modules linked in: scsi_debug x86_pkg_temp_thermal kvm_intel kvm irqbypass crc32c_intel joydev iTCO_wdt dcdbas ipmi_devintf acpi_power_meter iTCO_vendor_support ipmi_si imsghandler pcspkr wmi acpi_cpufreq tpm_tis tpm shpchp lpc_ich mfd_core nfsd nfs_acl lockd grace sunrpc tg3 ptp pps_core
Dec  3 13:22:02 localhost kernel: CPU: 2 PID: 28073 Comm: cat Not tainted 4.4.0-rc1+ #2
Dec  3 13:22:02 localhost kernel: Hardware name: Dell Inc. PowerEdge R320/08VT7V, BIOS 2.0.22 11/19/2013
Dec  3 13:22:02 localhost kernel: ffffffff81a20e77 ffff880613acfd18 ffffffff81321eef 0000000000000000
Dec  3 13:22:02 localhost kernel: ffff880613acfd50 ffffffff8107ca52 ffff88061176b198 0000000000000000
Dec  3 13:22:02 localhost kernel: ffffffff814542b0 ffff880610cfb100 ffff88061176b198 ffff880613acfd60
Dec  3 13:22:02 localhost kernel: Call Trace:
Dec  3 13:22:02 localhost kernel: [<ffffffff81321eef>] dump_stack+0x44/0x55
Dec  3 13:22:02 localhost kernel: [<ffffffff8107ca52>] warn_slowpath_common+0x82/0xc0
Dec  3 13:22:02 localhost kernel: [<ffffffff814542b0>] ? proc_scsi_show+0x20/0x20
Dec  3 13:22:02 localhost kernel: [<ffffffff8107cb4a>] warn_slowpath_null+0x1a/0x20
Dec  3 13:22:02 localhost kernel: [<ffffffff8167225d>] klist_iter_init_node+0x3d/0x50
Dec  3 13:22:02 localhost kernel: [<ffffffff81421d41>] bus_find_device+0x51/0xb0
Dec  3 13:22:02 localhost kernel: [<ffffffff814545ad>] scsi_seq_next+0x2d/0x40
[...]

And an eventual crash. It can actually occur in any hotplug system
which has a device finder and a starting device.

We can fix this globally by making sure the starting node for
klist_iter_init_node() is actually a member of the list before using it
(and by starting from the beginning if it isn't).

Reported-by: Ewan D. Milne <emilne@redhat.com>
Tested-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit 361cad3 upstream.

We've seen this in a packet capture - I've intermixed what I
think was going on. The fix here is to grab the so_lock sooner.

1964379 -> #1 open (for write) reply seqid=1
1964393 -> #2 open (for read) reply seqid=2

  __nfs4_close(), state->n_wronly--
  nfs4_state_set_mode_locked(), changes state->state = [R]
  state->flags is [RW]
  state->state is [R], state->n_wronly == 0, state->n_rdonly == 1

1964398 -> #3 open (for write) call -> because close is already running
1964399 -> downgrade (to read) call seqid=2 (close of #1)
1964402 -> #3 open (for write) reply seqid=3

 __update_open_stateid()
   nfs_set_open_stateid_locked(), changes state->flags
   state->flags is [RW]
   state->state is [R], state->n_wronly == 0, state->n_rdonly == 1
   new sequence number is exposed now via nfs4_stateid_copy()

   next step would be update_open_stateflags(), pending so_lock

1964403 -> downgrade reply seqid=2, fails with OLD_STATEID (close of #1)

   nfs4_close_prepare() gets so_lock and recalcs flags -> send close

1964405 -> downgrade (to read) call seqid=3 (close of #1 retry)

   __update_open_stateid() gets so_lock
 * update_open_stateflags() updates state->n_wronly.
   nfs4_state_set_mode_locked() updates state->state

   state->flags is [RW]
   state->state is [RW], state->n_wronly == 1, state->n_rdonly == 1

 * should have suppressed the preceding nfs4_close_prepare() from
   sending open_downgrade

1964406 -> write call
1964408 -> downgrade (to read) reply seqid=4 (close of #1 retry)

   nfs_clear_open_stateid_locked()
   state->flags is [R]
   state->state is [RW], state->n_wronly == 1, state->n_rdonly == 1

1964409 -> write reply (fails, openmode)

Signed-off-by: Andrew Elble <aweits@rit.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit 57adec8 upstream.

Calling apply_to_page_range with an empty range results in a BUG_ON
from the core code. This can be triggered by trying to load the st_drv
module with CONFIG_DEBUG_SET_MODULE_RONX enabled:

  kernel BUG at mm/memory.c:1874!
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 3 PID: 1764 Comm: insmod Not tainted 4.5.0-rc1+ #2
  Hardware name: ARM Juno development board (r0) (DT)
  task: ffffffc9763b8000 ti: ffffffc975af8000 task.ti: ffffffc975af8000
  PC is at apply_to_page_range+0x2cc/0x2d0
  LR is at change_memory_common+0x80/0x108

This patch fixes the issue by making change_memory_common (called by the
set_memory_* functions) a NOP when numpages == 0, therefore avoiding the
erroneous call to apply_to_page_range and bringing us into line with x86
and s390.

Reviewed-by: Laura Abbott <labbott@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit b3aff6c upstream.

Commit 4b4b451 ("arm/arm64: KVM: Rework the arch timer to use
level-triggered semantics") brought the virtual architected timer
closer to the VGIC. There is one occasion were we don't properly
check for the VGIC actually having been initialized before, but
instead go on to check the active state of some IRQ number.
If userland hasn't instantiated a virtual GIC, we end up with a
kernel NULL pointer dereference:
=========
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ffffffc9745c5000
[00000000] *pgd=00000009f631e003, *pud=00000009f631e003, *pmd=0000000000000000
Internal error: Oops: 96000006 [#2] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 2144 Comm: kvm_simplest-ar Tainted: G      D 4.5.0-rc2+ #1300
Hardware name: ARM Juno development board (r1) (DT)
task: ffffffc976da8000 ti: ffffffc976e28000 task.ti: ffffffc976e28000
PC is at vgic_bitmap_get_irq_val+0x78/0x90
LR is at kvm_vgic_map_is_active+0xac/0xc8
pc : [<ffffffc0000b7e28>] lr : [<ffffffc0000b972c>] pstate: 20000145
....
=========

Fix this by bailing out early of kvm_timer_flush_hwstate() if we don't
have a VGIC at all.

Reported-by: Cosmin Gorgovan <cosmin@linux-geek.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
[ Upstream commit 7716682 ]

Ilya reported following lockdep splat:

kernel: =========================
kernel: [ BUG: held lock freed! ]
kernel: 4.5.0-rc1-ceph-00026-g5e0a311 #1 Not tainted
kernel: -------------------------
kernel: swapper/5/0 is freeing memory
ffff880035c9d200-ffff880035c9dbff, with a lock still held there!
kernel: (&(&queue->rskq_lock)->rlock){+.-...}, at:
[<ffffffff816f6a88>] inet_csk_reqsk_queue_add+0x28/0xa0
kernel: 4 locks held by swapper/5/0:
kernel: #0:  (rcu_read_lock){......}, at: [<ffffffff8169ef6b>]
netif_receive_skb_internal+0x4b/0x1f0
kernel: #1:  (rcu_read_lock){......}, at: [<ffffffff816e977f>]
ip_local_deliver_finish+0x3f/0x380
kernel: #2:  (slock-AF_INET){+.-...}, at: [<ffffffff81685ffb>]
sk_clone_lock+0x19b/0x440
kernel: #3:  (&(&queue->rskq_lock)->rlock){+.-...}, at:
[<ffffffff816f6a88>] inet_csk_reqsk_queue_add+0x28/0xa0

To properly fix this issue, inet_csk_reqsk_queue_add() needs
to return to its callers if the child as been queued
into accept queue.

We also need to make sure listener is still there before
calling sk->sk_data_ready(), by holding a reference on it,
since the reference carried by the child can disappear as
soon as the child is put on accept queue.

Reported-by: Ilya Dryomov <idryomov@gmail.com>
Fixes: ebb516a ("tcp/dccp: fix race at listener dismantle phase")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
… and subvolume roots

commit f32e48e upstream.

The following call trace is seen when btrfs/031 test is executed in a loop,

[  158.661848] ------------[ cut here ]------------
[  158.662634] WARNING: CPU: 2 PID: 890 at /home/chandan/repos/linux/fs/btrfs/ioctl.c:558 create_subvol+0x3d1/0x6ea()
[  158.664102] BTRFS: Transaction aborted (error -2)
[  158.664774] Modules linked in:
[  158.665266] CPU: 2 PID: 890 Comm: btrfs Not tainted 4.4.0-rc6-g511711a #2
[  158.666251] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[  158.667392]  ffffffff81c0a6b0 ffff8806c7c4f8e8 ffffffff81431fc8 ffff8806c7c4f930
[  158.668515]  ffff8806c7c4f920 ffffffff81051aa1 ffff880c85aff000 ffff8800bb44d000
[  158.669647]  ffff8808863b5c98 0000000000000000 00000000fffffffe ffff8806c7c4f980
[  158.670769] Call Trace:
[  158.671153]  [<ffffffff81431fc8>] dump_stack+0x44/0x5c
[  158.671884]  [<ffffffff81051aa1>] warn_slowpath_common+0x81/0xc0
[  158.672769]  [<ffffffff81051b27>] warn_slowpath_fmt+0x47/0x50
[  158.673620]  [<ffffffff813bc98d>] create_subvol+0x3d1/0x6ea
[  158.674440]  [<ffffffff813777c9>] btrfs_mksubvol.isra.30+0x369/0x520
[  158.675376]  [<ffffffff8108a4aa>] ? percpu_down_read+0x1a/0x50
[  158.676235]  [<ffffffff81377a81>] btrfs_ioctl_snap_create_transid+0x101/0x180
[  158.677268]  [<ffffffff81377b52>] btrfs_ioctl_snap_create+0x52/0x70
[  158.678183]  [<ffffffff8137afb4>] btrfs_ioctl+0x474/0x2f90
[  158.678975]  [<ffffffff81144b8e>] ? vma_merge+0xee/0x300
[  158.679751]  [<ffffffff8115be31>] ? alloc_pages_vma+0x91/0x170
[  158.680599]  [<ffffffff81123f62>] ? lru_cache_add_active_or_unevictable+0x22/0x70
[  158.681686]  [<ffffffff813d99cf>] ? selinux_file_ioctl+0xff/0x1d0
[  158.682581]  [<ffffffff8117b791>] do_vfs_ioctl+0x2c1/0x490
[  158.683399]  [<ffffffff813d3cde>] ? security_file_ioctl+0x3e/0x60
[  158.684297]  [<ffffffff8117b9d4>] SyS_ioctl+0x74/0x80
[  158.685051]  [<ffffffff819b2bd7>] entry_SYSCALL_64_fastpath+0x12/0x6a
[  158.685958] ---[ end trace 4b63312de5a2cb76 ]---
[  158.686647] BTRFS: error (device loop0) in create_subvol:558: errno=-2 No such entry
[  158.709508] BTRFS info (device loop0): forced readonly
[  158.737113] BTRFS info (device loop0): disk space caching is enabled
[  158.738096] BTRFS error (device loop0): Remounting read-write after error is not allowed
[  158.851303] BTRFS error (device loop0): cleaner transaction attach returned -30

This occurs because,

Mount filesystem
Create subvol with ID 257
Unmount filesystem
Mount filesystem
Delete subvol with ID 257
  btrfs_drop_snapshot()
    Add root corresponding to subvol 257 into
    btrfs_transaction->dropped_roots list
Create new subvol (i.e. create_subvol())
  257 is returned as the next free objectid
  btrfs_read_fs_root_no_name()
    Finds the btrfs_root instance corresponding to the old subvol with ID 257
    in btrfs_fs_info->fs_roots_radix.
    Returns error since btrfs_root_item->refs has the value of 0.

To fix the issue the commit initializes tree root's and subvolume root's
highest_objectid when loading the roots from disk.

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit 4c58f32 upstream.

The fixes provided in this patch assigns a valid net_device structure to
skb before dispatching it for further processing.

Scenario #1:
============

Bluetooth 6lowpan receives an uncompressed IPv6 header, and dispatches it
to netif. The following error occurs:

Null pointer dereference error #1 crash log:

[  845.854013] BUG: unable to handle kernel NULL pointer dereference at
               0000000000000048
[  845.855785] IP: [<ffffffff816e3d36>] enqueue_to_backlog+0x56/0x240
...
[  845.909459] Call Trace:
[  845.911678]  [<ffffffff816e3f64>] netif_rx_internal+0x44/0xf0

The first modification fixes the NULL pointer dereference error by
assigning dev to the local_skb in order to set a valid net_device before
processing the skb by netif_rx_ni().

Scenario #2:
============

Bluetooth 6lowpan receives an UDP compressed message which needs further
decompression by nhc_udp. The following error occurs:

Null pointer dereference error #2 crash log:

[   63.295149] BUG: unable to handle kernel NULL pointer dereference at
               0000000000000840
[   63.295931] IP: [<ffffffffc0559540>] udp_uncompress+0x320/0x626
               [nhc_udp]

The second modification fixes the NULL pointer dereference error by
assigning dev to the local_skb in the case of a udp compressed packet.
The 6lowpan udp_uncompress function expects that the net_device is set in
the skb when checking lltype.

Signed-off-by: Glenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
Signed-off-by: Lukasz Duda <lukasz.duda@nordicsemi.no>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit 5610b12 upstream.

This patch is borrowed from x86 hpet driver and explaind below:

Due to the overly intelligent design of HPETs, we need to workaround
the problem that the compare value which we write is already behind
the actual counter value at the point where the value hits the real
compare register. This happens for two reasons:

1) We read out the counter, add the delta and write the result to the
   compare register. When a NMI hits between the read out and the write
   then the counter can be ahead of the event already.

2) The write to the compare register is delayed by up to two HPET
   cycles in AMD chipsets.

We can work around this by reading back the compare register to make
sure that the written value has hit the hardware. But that is bad
performance wise for the normal case where the event is far enough in
the future.

As we already know that the write can be delayed by up to two cycles
we can avoid the read back of the compare register completely if we
make the decision whether the delta has elapsed already or not based
on the following calculation:

  cmp = event - actual_count;

If cmp is less than 64 HPET clock cycles, then we decide that the event
has happened already and return -ETIME. That covers the above #1 and #2
problems which would cause a wait for HPET wraparound (~306 seconds).

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12162/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit cbfe74a upstream.

Returning to delay slot, riding an interrupti, had one loose end.
AUX_USER_SP used for restoring user mode SP upon RTIE was not being
setup from orig task's saved value, causing task to use wrong SP,
leading to ProtV errors.

The reason being:
 - INTERRUPT_EPILOGUE returns to a kernel trampoline, thus not expected to restore it
 - EXCEPTION_EPILOGUE is not used at all

Fix that by restoring AUX_USER_SP explicitly in the trampoline.

This was broken in the original workaround, but the error scenarios got
reduced considerably since v3.14 due to following:

 1. The Linuxthreads.old based userspace at the time caused many more
    exceptions in delay slot than the current NPTL based one.
    Infact with current userspace the error doesn't happen at all.

 2. Return from interrupt (delay slot or otherwise) doesn't get exercised much
    after commit 4de0e52 ("Really Re-enable interrupts to avoid deadlocks")
    since IRQ_ACTIVE.active being clear means most returns are as if from pure
    kernel (even for active interrupts)

Infact the issue only happened in an experimental branch where I was tinkering with
reverted 4de0e52

Fixes: 4255b07 ("ARCv2: STAR 9000793984: Handle return from intr to Delay Slot")
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit c2d6cb1 upstream.

While running a stress test I ran into a deadlock when running the delayed
iputs at transaction time, which produced the following report and trace:

[  886.399989] =============================================
[  886.400871] [ INFO: possible recursive locking detected ]
[  886.401663] 4.4.0-rc6-btrfs-next-18+ #1 Not tainted
[  886.402384] ---------------------------------------------
[  886.403182] fio/8277 is trying to acquire lock:
[  886.403568]  (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.403568]
[  886.403568] but task is already holding lock:
[  886.403568]  (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.403568]
[  886.403568] other info that might help us debug this:
[  886.403568]  Possible unsafe locking scenario:
[  886.403568]
[  886.403568]        CPU0
[  886.403568]        ----
[  886.403568]   lock(&fs_info->delayed_iput_sem);
[  886.403568]   lock(&fs_info->delayed_iput_sem);
[  886.403568]
[  886.403568]  *** DEADLOCK ***
[  886.403568]
[  886.403568]  May be due to missing lock nesting notation
[  886.403568]
[  886.403568] 3 locks held by fio/8277:
[  886.403568]  #0:  (sb_writers#11){.+.+.+}, at: [<ffffffff81174c4c>] __sb_start_write+0x5f/0xb0
[  886.403568]  #1:  (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffffa054620d>] btrfs_file_write_iter+0x73/0x408 [btrfs]
[  886.403568]  #2:  (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.403568]
[  886.403568] stack backtrace:
[  886.403568] CPU: 6 PID: 8277 Comm: fio Not tainted 4.4.0-rc6-btrfs-next-18+ #1
[  886.403568] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[  886.403568]  0000000000000000 ffff88009f80f770 ffffffff8125d4fd ffffffff82af1fc0
[  886.403568]  ffff88009f80f830 ffffffff8108e5f9 0000000200000000 ffff88009fd92290
[  886.403568]  0000000000000000 ffffffff82af1fc0 ffffffff829cfb01 00042b216d008804
[  886.403568] Call Trace:
[  886.403568]  [<ffffffff8125d4fd>] dump_stack+0x4e/0x79
[  886.403568]  [<ffffffff8108e5f9>] __lock_acquire+0xd42/0xf0b
[  886.403568]  [<ffffffff810c22db>] ? __module_address+0xdf/0x108
[  886.403568]  [<ffffffff8108eb77>] lock_acquire+0x10d/0x194
[  886.403568]  [<ffffffff8108eb77>] ? lock_acquire+0x10d/0x194
[  886.403568]  [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.489542]  [<ffffffff8148556b>] down_read+0x3e/0x4d
[  886.489542]  [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.489542]  [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.489542]  [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs]
[  886.489542]  [<ffffffffa0521d7a>] flush_space+0x435/0x44a [btrfs]
[  886.489542]  [<ffffffffa052218b>] ? reserve_metadata_bytes+0x26a/0x384 [btrfs]
[  886.489542]  [<ffffffffa05221ae>] reserve_metadata_bytes+0x28d/0x384 [btrfs]
[  886.489542]  [<ffffffffa052256c>] ? btrfs_block_rsv_refill+0x58/0x96 [btrfs]
[  886.489542]  [<ffffffffa0522584>] btrfs_block_rsv_refill+0x70/0x96 [btrfs]
[  886.489542]  [<ffffffffa053d747>] btrfs_evict_inode+0x394/0x55a [btrfs]
[  886.489542]  [<ffffffff81188e31>] evict+0xa7/0x15c
[  886.489542]  [<ffffffff81189878>] iput+0x1d3/0x266
[  886.489542]  [<ffffffffa053887c>] btrfs_run_delayed_iputs+0x8f/0xbf [btrfs]
[  886.489542]  [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs]
[  886.489542]  [<ffffffff81085096>] ? signal_pending_state+0x31/0x31
[  886.489542]  [<ffffffffa0521191>] btrfs_alloc_data_chunk_ondemand+0x1d7/0x288 [btrfs]
[  886.489542]  [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs]
[  886.489542]  [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs]
[  886.489542]  [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs]
[  886.489542]  [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128
[  886.489542]  [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs]
[  886.489542]  [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50
[  886.489542]  [<ffffffff8117279e>] __vfs_write+0x7c/0xa5
[  886.489542]  [<ffffffff81172cda>] vfs_write+0xa0/0xe4
[  886.489542]  [<ffffffff811734cc>] SyS_write+0x50/0x7e
[  886.489542]  [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
[ 1081.852335] INFO: task fio:8244 blocked for more than 120 seconds.
[ 1081.854348]       Not tainted 4.4.0-rc6-btrfs-next-18+ #1
[ 1081.857560] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1081.863227] fio        D ffff880213f9bb28     0  8244   8240 0x00000000
[ 1081.868719]  ffff880213f9bb28 00ffffff810fc6b0 ffffffff0000000a ffff88023ed55240
[ 1081.872499]  ffff880206b5d400 ffff880213f9c000 ffff88020a4d5318 ffff880206b5d400
[ 1081.876834]  ffffffff00000001 ffff880206b5d400 ffff880213f9bb40 ffffffff81482ba4
[ 1081.880782] Call Trace:
[ 1081.881793]  [<ffffffff81482ba4>] schedule+0x7f/0x97
[ 1081.883340]  [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325
[ 1081.895525]  [<ffffffff8108d48d>] ? trace_hardirqs_on_caller+0x16/0x1ab
[ 1081.897419]  [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20
[ 1081.899251]  [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20
[ 1081.901063]  [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21
[ 1081.902365]  [<ffffffff814855bd>] down_write+0x43/0x57
[ 1081.903846]  [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs]
[ 1081.906078]  [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs]
[ 1081.908846]  [<ffffffff8108d461>] ? mark_held_locks+0x56/0x6c
[ 1081.910409]  [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs]
[ 1081.912482]  [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs]
[ 1081.914597]  [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs]
[ 1081.919037]  [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128
[ 1081.920754]  [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs]
[ 1081.922496]  [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50
[ 1081.923922]  [<ffffffff8117279e>] __vfs_write+0x7c/0xa5
[ 1081.925275]  [<ffffffff81172cda>] vfs_write+0xa0/0xe4
[ 1081.926584]  [<ffffffff811734cc>] SyS_write+0x50/0x7e
[ 1081.927968]  [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
[ 1081.985293] INFO: lockdep is turned off.
[ 1081.986132] INFO: task fio:8249 blocked for more than 120 seconds.
[ 1081.987434]       Not tainted 4.4.0-rc6-btrfs-next-18+ #1
[ 1081.988534] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1081.990147] fio        D ffff880218febbb8     0  8249   8240 0x00000000
[ 1081.991626]  ffff880218febbb8 00ffffff81486b8e ffff88020000000b ffff88023ed75240
[ 1081.993258]  ffff8802120a9a00 ffff880218fec000 ffff88020a4d5318 ffff8802120a9a00
[ 1081.994850]  ffffffff00000001 ffff8802120a9a00 ffff880218febbd0 ffffffff81482ba4
[ 1081.996485] Call Trace:
[ 1081.997037]  [<ffffffff81482ba4>] schedule+0x7f/0x97
[ 1081.998017]  [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325
[ 1081.999241]  [<ffffffff810852a5>] ? finish_wait+0x6d/0x76
[ 1082.000306]  [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20
[ 1082.001533]  [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20
[ 1082.002776]  [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21
[ 1082.003995]  [<ffffffff814855bd>] down_write+0x43/0x57
[ 1082.005000]  [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs]
[ 1082.007403]  [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs]
[ 1082.008988]  [<ffffffffa0545064>] btrfs_fallocate+0x7c1/0xc2f [btrfs]
[ 1082.010193]  [<ffffffff8108a1ba>] ? percpu_down_read+0x4e/0x77
[ 1082.011280]  [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0
[ 1082.012265]  [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0
[ 1082.013021]  [<ffffffff811712e4>] vfs_fallocate+0x170/0x1ff
[ 1082.013738]  [<ffffffff81181ebb>] ioctl_preallocate+0x89/0x9b
[ 1082.014778]  [<ffffffff811822d7>] do_vfs_ioctl+0x40a/0x4ea
[ 1082.015778]  [<ffffffff81176ea7>] ? SYSC_newfstat+0x25/0x2e
[ 1082.016806]  [<ffffffff8118b4de>] ? __fget_light+0x4d/0x71
[ 1082.017789]  [<ffffffff8118240e>] SyS_ioctl+0x57/0x79
[ 1082.018706]  [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f

This happens because we can recursively acquire the semaphore
fs_info->delayed_iput_sem when attempting to allocate space to satisfy
a file write request as shown in the first trace above - when committing
a transaction we acquire (down_read) the semaphore before running the
delayed iputs, and when running a delayed iput() we can end up calling
an inode's eviction handler, which in turn commits another transaction
and attempts to acquire (down_read) again the semaphore to run more
delayed iput operations.
This results in a deadlock because if a task acquires multiple times a
semaphore it should invoke down_read_nested() with a different lockdep
class for each level of recursion.

Fix this by simplifying the implementation and use a mutex instead that
is acquired by the cleaner kthread before it runs the delayed iputs
instead of always acquiring a semaphore before delayed references are
run from anywhere.

Fixes: d7c1517 (btrfs: Fix NO_SPACE bug caused by delayed-iput)
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit 79e3f4a upstream.

Commit cbce790 ("PCI: designware: Make driver arch-agnostic") changed
the host bridge sysdata pointer from the ARM pci_sys_data to the DesignWare
pcie_port structure, and changed pcie-designware.c to reflect that.  But it
did not change the corresponding code in pci-keystone-dw.c, so it caused
crashes on Keystone:

  Unable to handle kernel NULL pointer dereference at virtual address 00000030
  pgd = c0003000
  [00000030] *pgd=80000800004003, *pmd=00000000
  Internal error: Oops: 206 [#1] PREEMPT SMP ARM
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.2-00139-gb74f926 #2
  Hardware name: Keystone
  PC is at ks_dw_pcie_msi_irq_unmask+0x24/0x58

Change pci-keystone-dw.c to expect sysdata to be the struct pcie_port
pointer.

[bhelgaas: changelog]
Fixes: cbce790 ("PCI: designware: Make driver arch-agnostic")
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit d144dfe upstream.

If we use USB ID pin as wakeup source, and there is a USB block
device on this USB OTG (ID) cable, the system will be deadlock
after system resume.

The root cause for this problem is: the workqueue ci_otg may try
to remove hcd before the driver resume has finished, and hcd will
disconnect the device on it, then, it will call device_release_driver,
and holds the device lock "dev->mutex", but it is never unlocked since
it waits workqueue writeback to run to flush the block information, but
the workqueue writeback is freezable, it is not thawed before driver
resume has finished.

When the driver (device: sd 0:0:0:0:) resume goes to dpm_complete, it
tries to get its device lock "dev->mutex", but it can't get it forever,
then the deadlock occurs. Below call stacks show the situation.

So, in order to fix this problem, we need to change workqueue ci_otg
as freezable, then the work item in this workqueue will be run after
driver's resume, this workqueue will not be blocked forever like above
case since the workqueue writeback has been thawed too.

Tested at: i.mx6qdl-sabresd and i.mx6sx-sdb.

[  555.178869] kworker/u2:13   D c07de74c     0   826      2 0x00000000
[  555.185310] Workqueue: ci_otg ci_otg_work
[  555.189353] Backtrace:
[  555.191849] [<c07de4fc>] (__schedule) from [<c07dec6c>] (schedule+0x48/0xa0)
[  555.198912]  r10:ee471ba0 r9:00000000 r8:00000000 r7:00000002 r6:ee470000 r5:ee471ba4
[  555.206867]  r4:ee470000
[  555.209453] [<c07dec24>] (schedule) from [<c07e2fc4>] (schedule_timeout+0x15c/0x1e0)
[  555.217212]  r4:7fffffff r3:edc2b000
[  555.220862] [<c07e2e68>] (schedule_timeout) from [<c07df6c8>] (wait_for_common+0x94/0x144)
[  555.229140]  r8:00000000 r7:00000002 r6:ee470000 r5:ee471ba4 r4:7fffffff
[  555.235980] [<c07df634>] (wait_for_common) from [<c07df790>] (wait_for_completion+0x18/0x1c)
[  555.244430]  r10:00000001 r9:c0b5563c r8:c0042e48 r7:ef086000 r6:eea4372c r5:ef131b00
[  555.252383]  r4:00000000
[  555.254970] [<c07df778>] (wait_for_completion) from [<c0043cb8>] (flush_work+0x19c/0x234)
[  555.263177] [<c0043b1c>] (flush_work) from [<c0043fac>] (flush_delayed_work+0x48/0x4c)
[  555.271106]  r8:ed5b5000 r7:c0b38a3c r6:eea439cc r5:eea4372c r4:eea4372c
[  555.277958] [<c0043f64>] (flush_delayed_work) from [<c00eae18>] (bdi_unregister+0x84/0xec)
[  555.286236]  r4:eea43520 r3:20000153
[  555.289885] [<c00ead94>] (bdi_unregister) from [<c02c2154>] (blk_cleanup_queue+0x180/0x29c)
[  555.298250]  r5:eea43808 r4:eea43400
[  555.301909] [<c02c1fd4>] (blk_cleanup_queue) from [<c0417914>] (__scsi_remove_device+0x48/0xb8)
[  555.310623]  r7:00000000 r6:20000153 r5:ededa950 r4:ededa800
[  555.316403] [<c04178cc>] (__scsi_remove_device) from [<c0415e90>] (scsi_forget_host+0x64/0x68)
[  555.325028]  r5:ededa800 r4:ed5b5000
[  555.328689] [<c0415e2c>] (scsi_forget_host) from [<c0409828>] (scsi_remove_host+0x78/0x104)
[  555.337054]  r5:ed5b5068 r4:ed5b5000
[  555.340709] [<c04097b0>] (scsi_remove_host) from [<c04cdfcc>] (usb_stor_disconnect+0x50/0xb4)
[  555.349247]  r6:ed5b56e4 r5:ed5b5818 r4:ed5b5690 r3:00000008
[  555.355025] [<c04cdf7c>] (usb_stor_disconnect) from [<c04b3bc8>] (usb_unbind_interface+0x78/0x25c)
[  555.363997]  r8:c13919b4 r7:edd3c000 r6:edd3c020 r5:ee551c68 r4:ee551c00 r3:c04cdf7c
[  555.371892] [<c04b3b50>] (usb_unbind_interface) from [<c03dc248>] (__device_release_driver+0x8c/0x118)
[  555.381213]  r10:00000001 r9:edd90c00 r8:c13919b4 r7:ee551c68 r6:c0b546e0 r5:c0b5563c
[  555.389167]  r4:edd3c020
[  555.391752] [<c03dc1bc>] (__device_release_driver) from [<c03dc2fc>] (device_release_driver+0x28/0x34)
[  555.401071]  r5:edd3c020 r4:edd3c054
[  555.404721] [<c03dc2d4>] (device_release_driver) from [<c03db304>] (bus_remove_device+0xe0/0x110)
[  555.413607]  r5:edd3c020 r4:ef17f04c
[  555.417253] [<c03db224>] (bus_remove_device) from [<c03d8128>] (device_del+0x114/0x21c)
[  555.425270]  r6:edd3c028 r5:edd3c020 r4:ee551c00 r3:00000000
[  555.431045] [<c03d8014>] (device_del) from [<c04b1560>] (usb_disable_device+0xa4/0x1e8)
[  555.439061]  r8:edd3c000 r7:eded8000 r6:00000000 r5:00000001 r4:ee551c00
[  555.445906] [<c04b14bc>] (usb_disable_device) from [<c04a8e54>] (usb_disconnect+0x74/0x224)
[  555.454271]  r9:edd90c00 r8:ee551000 r7:ee551c68 r6:ee551c9c r5:ee551c00 r4:00000001
[  555.462156] [<c04a8de0>] (usb_disconnect) from [<c04a8fb8>] (usb_disconnect+0x1d8/0x224)
[  555.470259]  r10:00000001 r9:edd90000 r8:ee471e2c r7:ee551468 r6:ee55149c r5:ee551400
[  555.478213]  r4:00000001
[  555.480797] [<c04a8de0>] (usb_disconnect) from [<c04ae5ec>] (usb_remove_hcd+0xa0/0x1ac)
[  555.488813]  r10:00000001 r9:ee471eb0 r8:00000000 r7:ef3d9500 r6:eded810c r5:eded80b0
[  555.496765]  r4:eded8000
[  555.499351] [<c04ae54c>] (usb_remove_hcd) from [<c04d4158>] (host_stop+0x28/0x64)
[  555.506847]  r6:eeb50010 r5:eded8000 r4:eeb51010
[  555.511563] [<c04d4130>] (host_stop) from [<c04d09b8>] (ci_otg_work+0xc4/0x124)
[  555.518885]  r6:00000001 r5:eeb50010 r4:eeb502a0 r3:c04d4130
[  555.524665] [<c04d08f4>] (ci_otg_work) from [<c00454f0>] (process_one_work+0x194/0x420)
[  555.532682]  r6:ef086000 r5:eeb502a0 r4:edc44480
[  555.537393] [<c004535c>] (process_one_work) from [<c00457b0>] (worker_thread+0x34/0x514)
[  555.545496]  r10:edc44480 r9:ef086000 r8:c0b1a100 r7:ef086034 r6:00000088 r5:edc44498
[  555.553450]  r4:ef086000
[  555.556032] [<c004577c>] (worker_thread) from [<c004bab4>] (kthread+0xdc/0xf8)
[  555.563268]  r10:00000000 r9:00000000 r8:00000000 r7:c004577c r6:edc44480 r5:eddc15c0
[  555.571221]  r4:00000000
[  555.573804] [<c004b9d8>] (kthread) from [<c000fef0>] (ret_from_fork+0x14/0x24)
[  555.581040]  r7:00000000 r6:00000000 r5:c004b9d8 r4:eddc15c0

[  553.429383] sh              D c07de74c     0   694    691 0x00000000
[  553.435801] Backtrace:
[  553.438295] [<c07de4fc>] (__schedule) from [<c07dec6c>] (schedule+0x48/0xa0)
[  553.445358]  r10:edd3c054 r9:edd3c078 r8:edddbd50 r7:edcbbc00 r6:c1377c34 r5:60000153
[  553.453313]  r4:eddda000
[  553.455896] [<c07dec24>] (schedule) from [<c07deff8>] (schedule_preempt_disabled+0x10/0x14)
[  553.464261]  r4:edd3c058 r3:0000000a
[  553.467910] [<c07defe8>] (schedule_preempt_disabled) from [<c07e0bbc>] (mutex_lock_nested+0x1a0/0x3e8)
[  553.477254] [<c07e0a1c>] (mutex_lock_nested) from [<c03e927c>] (dpm_complete+0xc0/0x1b0)
[  553.485358]  r10:00561408 r9:edd3c054 r8:c0b4863c r7:edddbd90 r6:c0b485d8 r5:edd3c020
[  553.493313]  r4:edd3c0d0
[  553.495896] [<c03e91bc>] (dpm_complete) from [<c03e9388>] (dpm_resume_end+0x1c/0x20)
[  553.503652]  r9:00000000 r8:c0b1a9d0 r7:c1334ec0 r6:c1334edc r5:00000003 r4:00000010
[  553.511544] [<c03e936c>] (dpm_resume_end) from [<c0079894>] (suspend_devices_and_enter+0x158/0x504)
[  553.520604]  r4:00000000 r3:c1334efc
[  553.524250] [<c007973c>] (suspend_devices_and_enter) from [<c0079e74>] (pm_suspend+0x234/0x2cc)
[  553.532961]  r10:00561408 r9:ed6b7300 r8:00000004 r7:c1334eec r6:00000000 r5:c1334ee8
[  553.540914]  r4:00000003
[  553.543493] [<c0079c40>] (pm_suspend) from [<c0078a6c>] (state_store+0x6c/0xc0)

[  555.703684] 7 locks held by kworker/u2:13/826:
[  555.708140]  #0:  ("%s""ci_otg"){++++.+}, at: [<c0045484>] process_one_work+0x128/0x420
[  555.716277]  #1:  ((&ci->work)){+.+.+.}, at: [<c0045484>] process_one_work+0x128/0x420
[  555.724317]  #2:  (usb_bus_list_lock){+.+.+.}, at: [<c04ae5e4>] usb_remove_hcd+0x98/0x1ac
[  555.732626]  #3:  (&dev->mutex){......}, at: [<c04a8e28>] usb_disconnect+0x48/0x224
[  555.740403]  #4:  (&dev->mutex){......}, at: [<c04a8e28>] usb_disconnect+0x48/0x224
[  555.748179]  #5:  (&dev->mutex){......}, at: [<c03dc2f4>] device_release_driver+0x20/0x34
[  555.756487]  #6:  (&shost->scan_mutex){+.+.+.}, at: [<c04097d0>] scsi_remove_host+0x20/0x104

Cc: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit 6acfe68 upstream.

Request-based DM's blk-mq support (dm-mq) was reported to be 50% slower
than if an underlying null_blk device were used directly.  One of the
reasons for this drop in performance is that blk_insert_clone_request()
was calling blk_mq_insert_request() with @async=true.  This forced the
use of kblockd_schedule_delayed_work_on() to run the blk-mq hw queues
which ushered in ping-ponging between process context (fio in this case)
and kblockd's kworker to submit the cloned request.  The ftrace
function_graph tracer showed:

  kworker-2013  =>   fio-12190
  fio-12190    =>  kworker-2013
  ...
  kworker-2013  =>   fio-12190
  fio-12190    =>  kworker-2013
  ...

Fixing blk_insert_clone_request()'s blk_mq_insert_request() call to
_not_ use kblockd to submit the cloned requests isn't enough to
eliminate the observed context switches.

In addition to this dm-mq specific blk-core fix, there are 2 DM core
fixes to dm-mq that (when paired with the blk-core fix) completely
eliminate the observed context switching:

1)  don't blk_mq_run_hw_queues in blk-mq request completion

    Motivated by desire to reduce overhead of dm-mq, punting to kblockd
    just increases context switches.

    In my testing against a really fast null_blk device there was no benefit
    to running blk_mq_run_hw_queues() on completion (and no other blk-mq
    driver does this).  So hopefully this change doesn't induce the need for
    yet another revert like commit 621739b !

2)  use blk_mq_complete_request() in dm_complete_request()

    blk_complete_request() doesn't offer the traditional q->mq_ops vs
    .request_fn branching pattern that other historic block interfaces
    do (e.g. blk_get_request).  Using blk_mq_complete_request() for
    blk-mq requests is important for performance.  It should be noted
    that, like blk_complete_request(), blk_mq_complete_request() doesn't
    natively handle partial completions -- but the request-based
    DM-multipath target does provide the required partial completion
    support by dm.c:end_clone_bio() triggering requeueing of the request
    via dm-mpath.c:multipath_end_io()'s return of DM_ENDIO_REQUEUE.

dm-mq fix #2 is _much_ more important than #1 for eliminating the
context switches.
Before: cpu          : usr=15.10%, sys=59.39%, ctx=7905181, majf=0, minf=475
After:  cpu          : usr=20.60%, sys=79.35%, ctx=2008, majf=0, minf=472

With these changes multithreaded async read IOPs improved from ~950K
to ~1350K for this dm-mq stacked on null_blk test-case.  The raw read
IOPs of the underlying null_blk device for the same workload is ~1950K.

Fixes: 7fb4898 ("block: add blk-mq support to blk_insert_cloned_request()")
Fixes: bfebd1c ("dm: add full blk-mq support to request-based DM")
Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
[ Upstream commit 9b36881 ]

We need to update the skb->csum after pulling the skb, otherwise
an unnecessary checksum (re)computation can ocure for IGMP/MLD packets
in the bridge code. Additionally this fixes the following splats for
network devices / bridge ports with support for and enabled RX checksum
offloading:

[...]
[   43.986968] eth0: hw csum failure
[   43.990344] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.4.0 #2
[   43.996193] Hardware name: BCM2709
[   43.999647] [<800204e0>] (unwind_backtrace) from [<8001cf14>] (show_stack+0x10/0x14)
[   44.007432] [<8001cf14>] (show_stack) from [<801ab614>] (dump_stack+0x80/0x90)
[   44.014695] [<801ab614>] (dump_stack) from [<802e4548>] (__skb_checksum_complete+0x6c/0xac)
[   44.023090] [<802e4548>] (__skb_checksum_complete) from [<803a055c>] (ipv6_mc_validate_checksum+0x104/0x178)
[   44.032959] [<803a055c>] (ipv6_mc_validate_checksum) from [<802e111c>] (skb_checksum_trimmed+0x130/0x188)
[   44.042565] [<802e111c>] (skb_checksum_trimmed) from [<803a06e8>] (ipv6_mc_check_mld+0x118/0x338)
[   44.051501] [<803a06e8>] (ipv6_mc_check_mld) from [<803b2c98>] (br_multicast_rcv+0x5dc/0xd00)
[   44.060077] [<803b2c98>] (br_multicast_rcv) from [<803aa510>] (br_handle_frame_finish+0xac/0x51c)
[...]

Fixes: 9afd85c ("net: Export IGMP/MLD message validation code")
Reported-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit cf0a254 upstream.

BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917
in_atomic(): 1, irqs_disabled(): 128, pid: 383, name: sh
Preemption disabled at:[<ffff800000124c18>] kgdb_cpu_enter+0x158/0x6b8

CPU: 3 PID: 383 Comm: sh Tainted: G        W       4.1.13-rt13 #2
Hardware name: Freescale Layerscape 2085a RDB Board (DT)
Call trace:
[<ffff8000000885e8>] dump_backtrace+0x0/0x128
[<ffff800000088734>] show_stack+0x24/0x30
[<ffff80000079a7c4>] dump_stack+0x80/0xa0
[<ffff8000000bd324>] ___might_sleep+0x18c/0x1a0
[<ffff8000007a20ac>] __rt_spin_lock+0x2c/0x40
[<ffff8000007a2268>] rt_read_lock+0x40/0x58
[<ffff800000085328>] single_step_handler+0x38/0xd8
[<ffff800000082368>] do_debug_exception+0x58/0xb8
Exception stack(0xffff80834a1e7c80 to 0xffff80834a1e7da0)
7c80: ffffff9c ffffffff 92c23ba0 0000ffff 4a1e7e4 ffff8083 001bfcc4 ffff8000
7ca0: f2000400 00000000 00000000 00000000 4a1e7d80 ffff8083 0049501c ffff8000
7cc0: 00005402 00000000 00aaa210 ffff8000 4a1e7ea0 ffff8083 000833f4 ffff8000
7ce0: ffffff9c ffffffff 92c23ba0 0000ffff 4a1e7ea0 ffff8083 001bfcc0 ffff8000
7d00: 4a0fc400 ffff8083 00005402 00000000 4a1e7d40 ffff8083 00490324 ffff8000
7d20: ffffff9c 00000000 92c23ba0 0000ffff 000a0000 00000000 00000000 00000000
7d40: 00000008 00000000 00080000 00000000 92c23b8b 0000ffff 92c23b8e 0000ffff
7d60: 00000038 00000000 00001cb2 00000000 00000005 00000000 92d7b498 0000ffff
7d80: 01010101 01010101 92be9000 0000ffff 00000000 00000000 00000030 00000000
[<ffff8000000833f4>] el1_dbg+0x18/0x6c

This issue is similar with 62c6c61("arm64: replace read_lock to rcu lock in
call_break_hook"), but comes to single_step_handler.

This also solves kgdbts boot test silent hang issue on 4.4 -rt kernel.

Signed-off-by: Yang Shi <yang.shi@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit 1342e0b upstream.

Tracing a workload that uses transactions gave a seg fault as follows:

  perf record -e intel_pt// workload
  perf report
  Program received signal SIGSEGV, Segmentation fault.
  0x000000000054b58c in intel_pt_reset_last_branch_rb (ptq=0x1a36110)
  	at util/intel-pt.c:929
  929 ptq->last_branch_rb->nr = 0;
  (gdb) p ptq->last_branch_rb
  $1 = (struct branch_stack *) 0x0
  (gdb) up
  1148 intel_pt_reset_last_branch_rb(ptq);
  (gdb) l
  1143 if (ret)
  1144 pr_err("Intel Processor Trace: failed to deliver transaction event
  1145 ret);
  1146
  1147 if (pt->synth_opts.callchain)
  1148 intel_pt_reset_last_branch_rb(ptq);
  1149
  1150 return ret;
  1151 }
  1152
  (gdb) p pt->synth_opts.callchain
  $2 = true
  (gdb)
  (gdb) bt
   #0 0x000000000054b58c in intel_pt_reset_last_branch_rb (ptq=0x1a36110)
   #1 0x000000000054c1e0 in intel_pt_synth_transaction_sample (ptq=0x1a36110)
   #2 0x000000000054c5b2 in intel_pt_sample (ptq=0x1a36110)

Caused by checking the 'callchain' flag when it should have been the
'last_branch' flag.  Fix that.

Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Fixes: f14445e ("perf intel-pt: Support generating branch stack")
Link: http://lkml.kernel.org/r/1460977068-11566-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Jun 21, 2016
commit b49b927 upstream.

We shouldn't be calling clk_prepare_enable()/clk_prepare_disable()
in an atomic context.

Fixes the following issue:

[    5.830970] ehci-omap: OMAP-EHCI Host Controller driver
[    5.830974] driver_register 'ehci-omap'
[    5.895849] driver_register 'wl1271_sdio'
[    5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
[    5.896876] 4 locks held by udevd/994:
[    5.896904]  #0:  (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
[    5.896923]  #1:  (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
[    5.896946]  #2:  (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
[    5.896966]  #3:  (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
[    5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
[    5.897048] Preemption disabled at:[<  (null)>]   (null)
[    5.897051]
[    5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ torvalds#233
[    5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
[    5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
[    5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
[    5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
[    5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
[    5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
[    5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
[    5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
[    5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
[    5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
[    5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
[    5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
[    5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
[    5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
[    5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
[    5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
[    5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
[    5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
[    5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
[    5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
[    5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
[    5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
[    5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
[    5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
[    5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
[    5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
[    5.912697] ------------[ cut here ]------------
[    5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
[    5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())

Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Tested-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bgly pushed a commit that referenced this pull request Aug 31, 2016
BugLink: http://bugs.launchpad.net/bugs/1586418

An ENOMEM when creating a pair tty in tty_ldisc_setup causes a null
pointer dereference in devpts_kill_index because tty->link->driver_data
is NULL.  The oops was triggered with the pty stressor in stress-ng when
in a low memory condition.

tty_init_dev tries to clean up a tty_ldisc_setup ENOMEM error by calling
release_tty, however, this ultimately tries to clean up the NULL pair'd
tty in pty_unix98_remove, triggering the Oops.

Add check to pty_unix98_remove to only clean up fsi if it is not NULL.

Ooops:

ops: 0000 [#1] SMP
[   23.020976] Modules linked in: ppdev snd_hda_codec_generic snd_hda_intel snd_hda_codec parport_pc snd_hda_core snd_hwdep parport snd_pcm input_leds joydev snd_timer serio_raw snd soundcore i2c_piix4 mac_hid ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel qxl aes_x86_64 ttm lrw gf128mul glue_helper ablk_helper drm_kms_helper cryptd syscopyarea sysfillrect psmouse sysimgblt floppy fb_sys_fops drm pata_acpi jitterentropy_rng drbg ansi_cprng
[   23.020978] CPU: 0 PID: 1452 Comm: stress-ng-pty Not tainted 4.7.0-rc4+ #2
[   23.020978] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[   23.020979] task: ffff88007ba30000 ti: ffff880078ea8000 task.ti: ffff880078ea8000
[   23.020981] RIP: 0010:[<ffffffff813f11ff>]  [<ffffffff813f11ff>] ida_remove+0x1f/0x120
[   23.020981] RSP: 0018:ffff880078eabb60  EFLAGS: 00010a03
[   23.020982] RAX: 4444444444444567 RBX: 0000000000000000 RCX: 000000000000001f
[   23.020982] RDX: 000000000000014c RSI: 000000000000026f RDI: 0000000000000000
[   23.020982] RBP: ffff880078eabb70 R08: 0000000000000004 R09: 0000000000000036
[   23.020983] R10: 000000000000026f R11: 0000000000000000 R12: 000000000000026f
[   23.020983] R13: 000000000000026f R14: ffff88007c944b40 R15: 000000000000026f
[   23.020984] FS:  00007f9a2f3cc700(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
[   23.020984] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   23.020985] CR2: 0000000000000010 CR3: 000000006c81b000 CR4: 00000000001406f0
[   23.020988] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   23.020988] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   23.020988] Stack:
[   23.020989]  0000000000000000 000000000000026f ffff880078eabb90 ffffffff812a5a99
[   23.020990]  0000000000000000 00000000fffffff4 ffff880078eabba8 ffffffff814f9cbe
[   23.020991]  ffff88007965c800 ffff880078eabbc8 ffffffff814eef43 fffffffffffffff4
[   23.020991] Call Trace:
[   23.021000]  [<ffffffff812a5a99>] devpts_kill_index+0x29/0x50
[   23.021002]  [<ffffffff814f9cbe>] pty_unix98_remove+0x2e/0x50
[   23.021006]  [<ffffffff814eef43>] release_tty+0xb3/0x1b0
[   23.021007]  [<ffffffff814f18d4>] tty_init_dev+0xd4/0x1c0
[   23.021011]  [<ffffffff814f9fae>] ptmx_open+0xae/0x190
[   23.021013]  [<ffffffff812254ef>] chrdev_open+0xbf/0x1b0
[   23.021015]  [<ffffffff8121d973>] do_dentry_open+0x203/0x310
[   23.021016]  [<ffffffff81225430>] ? cdev_put+0x30/0x30
[   23.021017]  [<ffffffff8121ee44>] vfs_open+0x54/0x80
[   23.021018]  [<ffffffff8122b8fc>] ? may_open+0x8c/0x100
[   23.021019]  [<ffffffff8122f26b>] path_openat+0x2eb/0x1440
[   23.021020]  [<ffffffff81230534>] ? putname+0x54/0x60
[   23.021022]  [<ffffffff814f6f97>] ? n_tty_ioctl_helper+0x27/0x100
[   23.021023]  [<ffffffff81231651>] do_filp_open+0x91/0x100
[   23.021024]  [<ffffffff81230596>] ? getname_flags+0x56/0x1f0
[   23.021026]  [<ffffffff8123fc66>] ? __alloc_fd+0x46/0x190
[   23.021027]  [<ffffffff8121f1e4>] do_sys_open+0x124/0x210
[   23.021028]  [<ffffffff8121f2ee>] SyS_open+0x1e/0x20
[   23.021035]  [<ffffffff81845576>] entry_SYSCALL_64_fastpath+0x1e/0xa8
[   23.021044] Code: 63 28 45 31 e4 eb dd 0f 1f 44 00 00 55 4c 63 d6 48 ba 89 88 88 88 88 88 88 88 4c 89 d0 b9 1f 00 00 00 48 f7 e2 48 89 e5 41 54 53 <8b> 47 10 48 89 fb 8d 3c c5 00 00 00 00 48 c1 ea 09 b8 01 00 00
[   23.021045] RIP  [<ffffffff813f11ff>] ida_remove+0x1f/0x120
[   23.021045]  RSP <ffff880078eabb60>
[   23.021046] CR2: 0000000000000010

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(backport of upstream commit 5353ed8)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
bgly pushed a commit that referenced this pull request Aug 31, 2016
BugLink: http://bugs.launchpad.net/bugs/1607404

commit 8e96a87 upstream.

Userspace can quite legitimately perform an exec() syscall with a
suspended transaction. exec() does not return to the old process, rather
it load a new one and starts that, the expectation therefore is that the
new process starts not in a transaction. Currently exec() is not treated
any differently to any other syscall which creates problems.

Firstly it could allow a new process to start with a suspended
transaction for a binary that no longer exists. This means that the
checkpointed state won't be valid and if the suspended transaction were
ever to be resumed and subsequently aborted (a possibility which is
exceedingly likely as exec()ing will likely doom the transaction) the
new process will jump to invalid state.

Secondly the incorrect attempt to keep the transactional state while
still zeroing state for the new process creates at least two TM Bad
Things. The first triggers on the rfid to return to userspace as
start_thread() has given the new process a 'clean' MSR but the suspend
will still be set in the hardware MSR. The second TM Bad Thing triggers
in __switch_to() as the processor is still transactionally suspended but
__switch_to() wants to zero the TM sprs for the new process.

This is an example of the outcome of calling exec() with a suspended
transaction. Note the first 700 is likely the first TM bad thing
decsribed earlier only the kernel can't report it as we've loaded
userspace registers. c000000000009980 is the rfid in
fast_exception_return()

  Bad kernel stack pointer 3fffcfa1a370 at c000000000009980
  Oops: Bad kernel stack pointer, sig: 6 [#1]
  CPU: 0 PID: 2006 Comm: tm-execed Not tainted
  NIP: c000000000009980 LR: 0000000000000000 CTR: 0000000000000000
  REGS: c00000003ffefd40 TRAP: 0700   Not tainted
  MSR: 8000000300201031 <SF,ME,IR,DR,LE,TM[SE]>  CR: 00000000  XER: 00000000
  CFAR: c0000000000098b4 SOFTE: 0
  PACATMSCRATCH: b00000010000d033
  GPR00: 0000000000000000 00003fffcfa1a370 0000000000000000 0000000000000000
  GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR12: 00003fff966611c0 0000000000000000 0000000000000000 0000000000000000
  NIP [c000000000009980] fast_exception_return+0xb0/0xb8
  LR [0000000000000000]           (null)
  Call Trace:
  Instruction dump:
  f84d0278 e9a100d8 7c7b03a6 e84101a0 7c4ff120 e8410170 7c5a03a6 e8010070
  e8410080 e8610088 e8810090 e8210078 <4c000024> 48000000 e8610178 88ed023b

  Kernel BUG at c000000000043e80 [verbose debug info unavailable]
  Unexpected TM Bad Thing exception at c000000000043e80 (msr 0x201033)
  Oops: Unrecoverable exception, sig: 6 [#2]
  CPU: 0 PID: 2006 Comm: tm-execed Tainted: G      D
  task: c0000000fbea6d80 ti: c00000003ffec000 task.ti: c0000000fb7ec000
  NIP: c000000000043e80 LR: c000000000015a24 CTR: 0000000000000000
  REGS: c00000003ffef7e0 TRAP: 0700   Tainted: G      D
  MSR: 8000000300201033 <SF,ME,IR,DR,RI,LE,TM[SE]>  CR: 28002828  XER: 00000000
  CFAR: c000000000015a20 SOFTE: 0
  PACATMSCRATCH: b00000010000d033
  GPR00: 0000000000000000 c00000003ffefa60 c000000000db5500 c0000000fbead000
  GPR04: 8000000300001033 2222222222222222 2222222222222222 00000000ff160000
  GPR08: 0000000000000000 800000010000d033 c0000000fb7e3ea0 c00000000fe00004
  GPR12: 0000000000002200 c00000000fe00000 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000000000000 0000000000000000 c0000000fbea7410 00000000ff160000
  GPR24: c0000000ffe1f600 c0000000fbea8700 c0000000fbea8700 c0000000fbead000
  GPR28: c000000000e20198 c0000000fbea6d80 c0000000fbeab680 c0000000fbea6d80
  NIP [c000000000043e80] tm_restore_sprs+0xc/0x1c
  LR [c000000000015a24] __switch_to+0x1f4/0x420
  Call Trace:
  Instruction dump:
  7c800164 4e800020 7c0022a6 f80304a8 7c0222a6 f80304b0 7c0122a6 f80304b8
  4e800020 e80304a8 7c0023a6 e80304b0 <7c0223a6> e80304b8 7c0123a6 4e800020

This fixes CVE-2016-5828.

Fixes: bc2a940 ("powerpc: Hook in new transactional memory code")
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
bgly pushed a commit that referenced this pull request Nov 2, 2016
BugLink: http://bugs.launchpad.net/bugs/1614560

commit edfe63e upstream.

A Xorg failure on qemu32 was reported as a regression [1] caused by
commit 9cd25aa ("x86/mm/pat: Emulate PAT when it is disabled").

This patch fixes the Xorg crash.

Negative effects of this regression were the following two failures [2]
in Xorg on QEMU with QEMU CPU model "qemu32" (-cpu qemu32), which were
triggered by the fact that its virtual CPU does not support MTRRs.

 #1. copy_process() failed in the check in reserve_pfn_range()

    copy_process
     copy_mm
      dup_mm
       dup_mmap
        copy_page_range
         track_pfn_copy
          reserve_pfn_range

 A WC map request was tracked as WC in memtype, which set a PTE as
 UC (pgprot) per __cachemode2pte_tbl[].  This led to this error in
 reserve_pfn_range() called from track_pfn_copy(), which obtained
 a pgprot from a PTE.  It converts pgprot to page_cache_mode, which
 does not necessarily result in the original page_cache_mode since
 __cachemode2pte_tbl[] redirects multiple types to UC.

 #2. error path in copy_process() then hit WARN_ON_ONCE in
     untrack_pfn().

     x86/PAT: Xorg:509 map pfn expected mapping type uncached-
     minus for [mem 0xfd000000-0xfdffffff], got write-combining
      Call Trace:
     dump_stack
     warn_slowpath_common
     ? untrack_pfn
     ? untrack_pfn
     warn_slowpath_null
     untrack_pfn
     ? __kunmap_atomic
     unmap_single_vma
     ? pagevec_move_tail_fn
     unmap_vmas
     exit_mmap
     mmput
     copy_process.part.47
     _do_fork
     SyS_clone
     do_syscall_32_irqs_on
     entry_INT80_32

These negative effects are caused by two separate bugs, but they
can be addressed in separate patches.  Fixing the pat_init() issue
described below addresses the root cause, and avoids Xorg to hit
these cases.

When the CPU does not support MTRRs, MTRR does not call pat_init(),
which leaves PAT enabled without initializing PAT.  This pat_init()
issue is a long-standing issue, but manifested as issue #1 (and then
hit issue #2) with the above-mentioned commit because the memtype
now tracks cache attribute with 'page_cache_mode'.

This pat_init() issue existed before the commit, but we used pgprot
in memtype.  Hence, we did not have issue #1 before.  But WC request
resulted in WT in effect because WC pgrot is actually WT when PAT
is not initialized.  This is not how it was designed to work.  When
PAT is set to disable properly, WC is converted to UC.  The use of
WT can result in a system crash if the target range does not support
WT.  Fortunately, nobody ran into such issue before.

To fix this pat_init() issue, PAT code has been enhanced to provide
pat_disable() interface.  Call this interface when MTRRs are disabled.
By setting PAT to disable properly, PAT bypasses the memtype check,
and avoids issue #1.

  [1]: https://lkml.org/lkml/2016/3/3/828
  [2]: https://lkml.org/lkml/2016/3/4/775

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: paul.gortmaker@windriver.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1458769323-24491-5-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
bgly pushed a commit that referenced this pull request Nov 2, 2016
BugLink: http://bugs.launchpad.net/bugs/1615620

commit bd975d1 upstream.

The secmech hmac(md5) structures are present in the TCP_Server_Info
struct and can be shared among multiple CIFS sessions.  However, the
server mutex is not currently held when these structures are allocated
and used, which can lead to a kernel crashes, as in the scenario below:

mount.cifs(8) #1				mount.cifs(8) #2

Is secmech.sdeschmaccmd5 allocated?
// false

						Is secmech.sdeschmaccmd5 allocated?
						// false

secmech.hmacmd = crypto_alloc_shash..
secmech.sdeschmaccmd5 = kzalloc..
sdeschmaccmd5->shash.tfm = &secmec.hmacmd;

						secmech.sdeschmaccmd5 = kzalloc
						// sdeschmaccmd5->shash.tfm
						// not yet assigned

crypto_shash_update()
 deref NULL sdeschmaccmd5->shash.tfm

 Unable to handle kernel paging request at virtual address 00000030
 epc   : 8027ba34 crypto_shash_update+0x38/0x158
 ra    : 8020f2e8 setup_ntlmv2_rsp+0x4bc/0xa84
 Call Trace:
  crypto_shash_update+0x38/0x158
  setup_ntlmv2_rsp+0x4bc/0xa84
  build_ntlmssp_auth_blob+0xbc/0x34c
  sess_auth_rawntlmssp_authenticate+0xac/0x248
  CIFS_SessSetup+0xf0/0x178
  cifs_setup_session+0x4c/0x84
  cifs_get_smb_ses+0x2c8/0x314
  cifs_mount+0x38c/0x76c
  cifs_do_mount+0x98/0x440
  mount_fs+0x20/0xc0
  vfs_kern_mount+0x58/0x138
  do_mount+0x1e8/0xccc
  SyS_mount+0x88/0xd4
  syscall_common+0x30/0x54

Fix this by locking the srv_mutex around the code which uses these
hmac(md5) structures.  All the other secmech algos already have similar
locking.

Fixes: 95dc8dd ("Limit allocation of crypto mechanisms to dialect which requires")
Signed-off-by: Rabin Vincent <rabinv@axis.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
bgly pushed a commit that referenced this pull request Nov 2, 2016
BugLink: https://bugs.launchpad.net/bugs/1616318

The USB core contains a bug that can show up when a USB-3 host
controller is removed.  If the primary (USB-2) hcd structure is
released before the shared (USB-3) hcd, the core will try to do a
double-free of the common bandwidth_mutex.

The problem was described in graphical form by Chung-Geol Kim, who
first reported it:

=================================================
     At *remove USB(3.0) Storage
     sequence <1> --> <5> ((Problem Case))
=================================================
                                  VOLD
------------------------------------|------------
                                 (uevent)
                            ________|_________
                           |<1>               |
                           |dwc3_otg_sm_work  |
                           |usb_put_hcd       |
                           |peer_hcd(kref=2)|
                           |__________________|
                            ________|_________
                           |<2>               |
                           |New USB BUS #2    |
                           |                  |
                           |peer_hcd(kref=1)  |
                           |                  |
                         --(Link)-bandXX_mutex|
                         | |__________________|
                         |
    ___________________  |
   |<3>                | |
   |dwc3_otg_sm_work   | |
   |usb_put_hcd        | |
   |primary_hcd(kref=1)| |
   |___________________| |
    _________|_________  |
   |<4>                | |
   |New USB BUS #1     | |
   |hcd_release        | |
   |primary_hcd(kref=0)| |
   |                   | |
   |bandXX_mutex(free) |<-
   |___________________|
                               (( VOLD ))
                            ______|___________
                           |<5>               |
                           |      SCSI        |
                           |usb_put_hcd       |
                           |peer_hcd(kref=0)  |
                           |*hcd_release      |
                           |bandXX_mutex(free*)|<- double free
                           |__________________|

=================================================

This happens because hcd_release() frees the bandwidth_mutex whenever
it sees a primary hcd being released (which is not a very good idea
in any case), but in the course of releasing the primary hcd, it
changes the pointers in the shared hcd in such a way that the shared
hcd will appear to be primary when it gets released.

This patch fixes the problem by changing hcd_release() so that it
deallocates the bandwidth_mutex only when the _last_ hcd structure
referencing it is released.  The patch also removes an unnecessary
test, so that when an hcd is released, both the shared_hcd and
primary_hcd pointers in the hcd's peer will be cleared.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Chung-Geol Kim <chunggeol.kim@samsung.com>
Tested-by: Chung-Geol Kim <chunggeol.kim@samsung.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ab2a4bf)
Signed-off-by: AceLan Kao <acelan.kao@canonical.com>
Acked-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Christopher Arges <chris.j.arges@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
bgly pushed a commit that referenced this pull request Nov 2, 2016
BugLink: http://bugs.launchpad.net/bugs/1618151

This patch leverages 'struct pci_host_bridge' from the PCI subsystem
in order to free the pci_controller only after the last reference to
its devices is dropped (avoiding an oops in pcibios_release_device()
if the last reference is dropped after pcibios_free_controller()).

The patch relies on pci_host_bridge.release_fn() (and .release_data),
which is called automatically by the PCI subsystem when the root bus
is released (i.e., the last reference is dropped).  Those fields are
set via pci_set_host_bridge_release() (e.g. in the platform-specific
implementation of pcibios_root_bridge_prepare()).

It introduces the 'pcibios_free_controller_deferred()' .release_fn()
and it expects .release_data to hold a pointer to the pci_controller.

The function implictly calls 'pcibios_free_controller()', so an user
must *NOT* explicitly call it if using the new _deferred() callback.

The functionality is enabled for pseries (although it isn't platform
specific, and may be used by cxl).

Details on not-so-elegant design choices:

 - Use 'pci_host_bridge.release_data' field as pointer to associated
   'struct pci_controller' so *not* to 'pci_bus_to_host(bridge->bus)'
   in pcibios_free_controller_deferred().

   That's because pci_remove_root_bus() sets 'host_bridge->bus = NULL'
   (so, if the last reference is released after pci_remove_root_bus()
   runs, which eventually reaches pcibios_free_controller_deferred(),
   that would hit a null pointer dereference).

   The cxl/vphb.c code calls pci_remove_root_bus(), and the cxl folks
   are interested in this fix.

Test-case #1 (hold references)

  # ls -ld /sys/block/sd* | grep -m1 0021:01:00.0
  <...> /sys/block/sdaa -> ../devices/pci0021:01/0021:01:00.0/<...>

  # ls -ld /sys/block/sd* | grep -m1 0021:01:00.1
  <...> /sys/block/sdab -> ../devices/pci0021:01/0021:01:00.1/<...>

  # cat >/dev/sdaa & pid1=$!
  # cat >/dev/sdab & pid2=$!

  # drmgr -w 5 -d 1 -c phb -s 'PHB 33' -r
  Validating PHB DLPAR capability...yes.
  [  594.306719] pci_hp_remove_devices: PCI: Removing devices on bus 0021:01
  [  594.306738] pci_hp_remove_devices:    Removing 0021:01:00.0...
  ...
  [  598.236381] pci_hp_remove_devices:    Removing 0021:01:00.1...
  ...
  [  611.972077] pci_bus 0021:01: busn_res: [bus 01-ff] is released
  [  611.972140] rpadlpar_io: slot PHB 33 removed

  # kill -9 $pid1
  # kill -9 $pid2
  [  632.918088] pcibios_free_controller_deferred: domain 33, dynamic 1

Test-case #2 (don't hold references)

  # drmgr -w 5 -d 1 -c phb -s 'PHB 33' -r
  Validating PHB DLPAR capability...yes.
  [  916.357363] pci_hp_remove_devices: PCI: Removing devices on bus 0021:01
  [  916.357386] pci_hp_remove_devices:    Removing 0021:01:00.0...
  ...
  [  920.566527] pci_hp_remove_devices:    Removing 0021:01:00.1...
  ...
  [  933.955873] pci_bus 0021:01: busn_res: [bus 01-ff] is released
  [  933.955977] pcibios_free_controller_deferred: domain 33, dynamic 1
  [  933.955999] rpadlpar_io: slot PHB 33 removed

Suggested-By: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> # cxl
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
(cherry picked from commit 2dd9c11)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Chris J Arges <chris.j.arges@canonical.com>
bgly pushed a commit that referenced this pull request Nov 2, 2016
BugLink: http://bugs.launchpad.net/bugs/1621113

commit adc8a43 upstream.

Done, because line6_stream_stop() locks and calls line6_unlink_audio_urbs(),
which in turn invokes audio_out_callback(), which tries to lock 2nd time.

Fixes:

=============================================
[ INFO: possible recursive locking detected ]
4.4.15+ #15 Not tainted
---------------------------------------------
mplayer/3591 is trying to acquire lock:
 (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa27655>] audio_out_callback+0x70/0x110 [snd_usb_line6]

but task is already holding lock:
 (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa26aad>] line6_stream_stop+0x24/0x5c [snd_usb_line6]

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&line6pcm->out.lock)->rlock);
  lock(&(&line6pcm->out.lock)->rlock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by mplayer/3591:
 #0:  (snd_pcm_link_rwlock){.-.-..}, at: [<bf8d49a7>] snd_pcm_stream_lock+0x1e/0x40 [snd_pcm]
 #1:  (&(&substream->self_group.lock)->rlock){-.-...}, at: [<bf8d49af>] snd_pcm_stream_lock+0x26/0x40 [snd_pcm]
 #2:  (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa26aad>] line6_stream_stop+0x24/0x5c [snd_usb_line6]

stack backtrace:
CPU: 0 PID: 3591 Comm: mplayer Not tainted 4.4.15+ #15
Hardware name: Generic AM33XX (Flattened Device Tree)
[<c0015d85>] (unwind_backtrace) from [<c001253d>] (show_stack+0x11/0x14)
[<c001253d>] (show_stack) from [<c02f1bdf>] (dump_stack+0x8b/0xac)
[<c02f1bdf>] (dump_stack) from [<c0076f43>] (__lock_acquire+0xc8b/0x1780)
[<c0076f43>] (__lock_acquire) from [<c007810d>] (lock_acquire+0x99/0x1c0)
[<c007810d>] (lock_acquire) from [<c06171e7>] (_raw_spin_lock_irqsave+0x3f/0x4c)
[<c06171e7>] (_raw_spin_lock_irqsave) from [<bfa27655>] (audio_out_callback+0x70/0x110 [snd_usb_line6])
[<bfa27655>] (audio_out_callback [snd_usb_line6]) from [<c04294db>] (__usb_hcd_giveback_urb+0x53/0xd0)
[<c04294db>] (__usb_hcd_giveback_urb) from [<c046388d>] (musb_giveback+0x3d/0x98)
[<c046388d>] (musb_giveback) from [<c04647f5>] (musb_urb_dequeue+0x6d/0x114)
[<c04647f5>] (musb_urb_dequeue) from [<c042ac11>] (usb_hcd_unlink_urb+0x39/0x98)
[<c042ac11>] (usb_hcd_unlink_urb) from [<bfa26a87>] (line6_unlink_audio_urbs+0x6a/0x6c [snd_usb_line6])
[<bfa26a87>] (line6_unlink_audio_urbs [snd_usb_line6]) from [<bfa26acb>] (line6_stream_stop+0x42/0x5c [snd_usb_line6])
[<bfa26acb>] (line6_stream_stop [snd_usb_line6]) from [<bfa26fe7>] (snd_line6_trigger+0xb6/0xf4 [snd_usb_line6])
[<bfa26fe7>] (snd_line6_trigger [snd_usb_line6]) from [<bf8d47b7>] (snd_pcm_do_stop+0x36/0x38 [snd_pcm])
[<bf8d47b7>] (snd_pcm_do_stop [snd_pcm]) from [<bf8d462f>] (snd_pcm_action_single+0x22/0x40 [snd_pcm])
[<bf8d462f>] (snd_pcm_action_single [snd_pcm]) from [<bf8d46f9>] (snd_pcm_action+0xac/0xb0 [snd_pcm])
[<bf8d46f9>] (snd_pcm_action [snd_pcm]) from [<bf8d4b61>] (snd_pcm_drop+0x38/0x64 [snd_pcm])
[<bf8d4b61>] (snd_pcm_drop [snd_pcm]) from [<bf8d6233>] (snd_pcm_common_ioctl1+0x7fe/0xbe8 [snd_pcm])
[<bf8d6233>] (snd_pcm_common_ioctl1 [snd_pcm]) from [<bf8d6779>] (snd_pcm_playback_ioctl1+0x15c/0x51c [snd_pcm])
[<bf8d6779>] (snd_pcm_playback_ioctl1 [snd_pcm]) from [<bf8d6b59>] (snd_pcm_playback_ioctl+0x20/0x28 [snd_pcm])
[<bf8d6b59>] (snd_pcm_playback_ioctl [snd_pcm]) from [<c016714b>] (do_vfs_ioctl+0x3af/0x5c8)

Fixes: 63e20df ('ALSA: line6: Reorganize PCM stream handling')
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Andrej Krutak <dev@andree.sk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
bgly pushed a commit that referenced this pull request Nov 30, 2016
TLDR; This changes the way that version strings are parsed in the packaging to
make it easier for me to maintain topic branches/PPA builds. There should
be no changes to how things work today for standard Ubuntu kernels. But,
it allows for topic-branch maintainers to add an optional ".X" in the ABI
name, for reasons described below.

<Regression Testing>
------------------
Old Parsing:
  = abinum =
  $ echo "33.58" | sed -e 's/\..*//'
  33
  = uploadnum =
  $ echo "33.58" | sed -e 's/.*\.//'
  58
  = abi =
  $ echo "33.58" | gawk -F. '{print $1}'
  33

New Parsing:
  = abinum =
  $ echo "33.58" | sed -r -e 's/([^\+]*)\.[^\.]+(\+.*)?$/\1/'
  33
  = uploadnum =
  $ echo "33.58" | sed -r -e 's/[^\+]*\.([^\.]+(\+.*)?$$)/\1/'
  58
  = abi =
  $ echo "33.58" | sed -r -e 's/([^\+]*)\.[^\.]+(\+.*)?$/\1/'
  33
</Regression Testing>

When maintaining topic customizations that track Ubuntu kernel releases, it
is nice have the following features:

 1) Ability to decipher the base Ubuntu kernel revision used from the topic
    kernel's revision number
 2) Use a version that dpkg sorts > the base Ubuntu version
 3) Use a version that dpkg sorts < the next expected Ubuntu version
 4) Ability to retains the same ABI as the base Ubuntu version when the
    ABI has indeed not changed. This helps with e.g. d-i compatibility.
 5) Make use of ABI tracking facilities (vs. just disabling them)

This is difficult to do with the current version scheme, which encodes the
ABI number in the version string:

  <upstream-version>-<abi>.<rev>

I can tack a "+topic.<N>" to the end of rev, we can solve 1-3, but only as
long as as the ABI is the same. Once the ABI changes, I don't have a good way
to bump it. If I increment the ABI, we'll overlap with the next Ubuntu ABI
(breaking #4). If we jump to a huge ABI number (e.g. x100 to go from 32 to
3200), we'll have a package revision that will never again upgrade to an Ubuntu
version (breaking #3), and never get back to the Ubuntu ABI (again breaking #4).
I can of course use a linux-meta package to e.g. transition from a 3200 ABI back
to a 32 ABI at the packaging level, but the bootloader will still consider
3200 to be newer and therefore the default.

I've therefore started using the following scheme:

  <upstream-version>-<abi>(.topicabi)?.<rev>(+<topic>.<topicrev>)?

Where topicabi must always be >= <rev> (ugly, but necessary).

If I don't break the ABI, I can then branch and return like so:

3.16.0-8.6 -------------------------------------------------> 3.16.0-8.7
   \                                                             ^
    \                                                            |
     \--> 3.16.0-8.6+topic.1 -------> 3.16.0-8.6+topic.2 --------/

If I do need to break the ABI, I can branch and return like so:

3.16.0-8.6 -------------------------------------------------> 3.16.0-9.1
   \                                                             ^
    \       ABI break #1                   ABI break #2          |
     \--> 3.16.0-8.6.6+topic.1 -------> 3.16.0-8.7.6+topic.2 ----/

Signed-off-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
bgly pushed a commit that referenced this pull request Nov 30, 2016
BugLink: http://bugs.launchpad.net/bugs/1637517

commit 420902c upstream.

If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can
deadlock our own worker - mount blocks kworker/3:2, sleeps forever more.

crash> ps|grep UN
    715      2   3  ffff880220734d30  UN   0.0       0      0  [kworker/3:2]
   9369   9341   2  ffff88021ffb7560  UN   1.3  493404 123184  Xorg
   9665   9664   3  ffff880225b92ab0  UN   0.0   47368    812  udisks-daemon
  10635  10403   3  ffff880222f22c70  UN   0.0   14904    936  mount
crash> bt ffff880220734d30
PID: 715    TASK: ffff880220734d30  CPU: 3   COMMAND: "kworker/3:2"
 #0 [ffff8802244c3c20] schedule at ffffffff8144584b
 #1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3
 #2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5
 #3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs]
 #4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs]
 #5 [ffff8802244c3e08] process_one_work at ffffffff81073726
 #6 [ffff8802244c3e68] worker_thread at ffffffff81073eba
 #7 [ffff8802244c3ec8] kthread at ffffffff810782e0
 #8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064
crash> rd ffff8802244c3cc8 10
ffff8802244c3cc8:  ffffffff814472b3 ffff880222f23250   .rD.....P2."....
ffff8802244c3cd8:  0000000000000000 0000000000000286   ................
ffff8802244c3ce8:  ffff8802244c3d30 ffff880220734d80   0=L$.....Ms ....
ffff8802244c3cf8:  ffff880222e8f628 0000000000000000   (.."............
ffff8802244c3d08:  0000000000000000 0000000000000002   ................
crash> struct rt_mutex ffff880222e8f628
struct rt_mutex {
  wait_lock = {
    raw_lock = {
      slock = 65537
    }
  },
  wait_list = {
    node_list = {
      next = 0xffff8802244c3d48,
      prev = 0xffff8802244c3d48
    }
  },
  owner = 0xffff880222f22c71,
  save_state = 0
}
crash> bt 0xffff880222f22c70
PID: 10635  TASK: ffff880222f22c70  CPU: 3   COMMAND: "mount"
 #0 [ffff8802216a9868] schedule at ffffffff8144584b
 #1 [ffff8802216a9910] schedule_timeout at ffffffff81446865
 #2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74
 #3 [ffff8802216a9a30] flush_work at ffffffff810712d3
 #4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463
 #5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba
 #6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632
 #7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c
 #8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs]
 #9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs]
    RIP: 00007f7b9303997a  RSP: 00007ffff443c7a8  RFLAGS: 00010202
    RAX: 00000000000000a5  RBX: ffffffff8144ef12  RCX: 00007f7b932e9ee0
    RDX: 00007f7b93d9a400  RSI: 00007f7b93d9a3e0  RDI: 00007f7b93d9a3c0
    RBP: 00007f7b93d9a2c0   R8: 00007f7b93d9a550   R9: 0000000000000001
    R10: ffffffffc0ed040e  R11: 0000000000000202  R12: 000000000000040e
    R13: 0000000000000000  R14: 00000000c0ed040e  R15: 00007ffff443ca20
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
bgly pushed a commit that referenced this pull request Nov 30, 2016
BugLink: http://bugs.launchpad.net/bugs/1637517

commit a818101 upstream.

An NULL-pointer dereference happens in cachefiles_mark_object_inactive()
when it tries to read i_blocks so that it can tell the cachefilesd daemon
how much space it's making available.

The problem is that cachefiles_drop_object() calls
cachefiles_mark_object_inactive() after calling cachefiles_delete_object()
because the object being marked active staves off attempts to (re-)use the
file at that filename until after it has been deleted.  This means that
d_inode is NULL by the time we come to try to access it.

To fix the problem, have the caller of cachefiles_mark_object_inactive()
supply the number of blocks freed up.

Without this, the following oops may occur:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
IP: [<ffffffffa06c5cc1>] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles]
...
CPU: 11 PID: 527 Comm: kworker/u64:4 Tainted: G          I    ------------   3.10.0-470.el7.x86_64 #1
Hardware name: Hewlett-Packard HP Z600 Workstation/0B54h, BIOS 786G4 v03.19 03/11/2011
Workqueue: fscache_object fscache_object_work_func [fscache]
task: ffff880035edaf10 ti: ffff8800b77c0000 task.ti: ffff8800b77c0000
RIP: 0010:[<ffffffffa06c5cc1>] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles]
RSP: 0018:ffff8800b77c3d70  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8800bf6cc400 RCX: 0000000000000034
RDX: 0000000000000000 RSI: ffff880090ffc710 RDI: ffff8800bf761ef8
RBP: ffff8800b77c3d88 R08: 2000000000000000 R09: 0090ffc710000000
R10: ff51005d2ff1c400 R11: 0000000000000000 R12: ffff880090ffc600
R13: ffff8800bf6cc520 R14: ffff8800bf6cc400 R15: ffff8800bf6cc498
FS:  0000000000000000(0000) GS:ffff8800bb8c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000098 CR3: 00000000019ba000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
 ffff880090ffc600 ffff8800bf6cc400 ffff8800867df140 ffff8800b77c3db0
 ffffffffa06c48cb ffff880090ffc600 ffff880090ffc180 ffff880090ffc658
 ffff8800b77c3df0 ffffffffa085d846 ffff8800a96b8150 ffff880090ffc600
Call Trace:
 [<ffffffffa06c48cb>] cachefiles_drop_object+0x6b/0xf0 [cachefiles]
 [<ffffffffa085d846>] fscache_drop_object+0xd6/0x1e0 [fscache]
 [<ffffffffa085d615>] fscache_object_work_func+0xa5/0x200 [fscache]
 [<ffffffff810a605b>] process_one_work+0x17b/0x470
 [<ffffffff810a6e96>] worker_thread+0x126/0x410
 [<ffffffff810a6d70>] ? rescuer_thread+0x460/0x460
 [<ffffffff810ae64f>] kthread+0xcf/0xe0
 [<ffffffff810ae580>] ? kthread_create_on_node+0x140/0x140
 [<ffffffff81695418>] ret_from_fork+0x58/0x90
 [<ffffffff810ae580>] ? kthread_create_on_node+0x140/0x140

The oopsing code shows:

	callq  0xffffffff810af6a0 <wake_up_bit>
	mov    0xf8(%r12),%rax
	mov    0x30(%rax),%rax
	mov    0x98(%rax),%rax   <---- oops here
	lock add %rax,0x130(%rbx)

where this is:

	d_backing_inode(object->dentry)->i_blocks

Fixes: a5b3a80 (CacheFiles: Provide read-and-reset release counters for cachefilesd)
Reported-by: Jianhong Yin <jiyin@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
bgly pushed a commit that referenced this pull request Nov 30, 2016
BugLink: http://bugs.launchpad.net/bugs/1637520

commit b6bc1c7 upstream.

Function ib_create_qp() was failing to return an error when
rdma_rw_init_mrs() fails, causing a crash further down in ib_create_qp()
when trying to dereferece the qp pointer which was actually a negative
errno.

The crash:

crash> log|grep BUG
[  136.458121] BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
crash> bt
PID: 3736   TASK: ffff8808543215c0  CPU: 2   COMMAND: "kworker/u64:2"
 #0 [ffff88084d323340] machine_kexec at ffffffff8105fbb0
 #1 [ffff88084d3233b0] __crash_kexec at ffffffff81116758
 #2 [ffff88084d323480] crash_kexec at ffffffff8111682d
 #3 [ffff88084d3234b0] oops_end at ffffffff81032bd6
 #4 [ffff88084d3234e0] no_context at ffffffff8106e431
 #5 [ffff88084d323530] __bad_area_nosemaphore at ffffffff8106e610
 #6 [ffff88084d323590] bad_area_nosemaphore at ffffffff8106e6f4
 #7 [ffff88084d3235a0] __do_page_fault at ffffffff8106ebdc
 #8 [ffff88084d323620] do_page_fault at ffffffff8106f057
 #9 [ffff88084d323660] page_fault at ffffffff816e3148
    [exception RIP: ib_create_qp+427]
    RIP: ffffffffa02554fb  RSP: ffff88084d323718  RFLAGS: 00010246
    RAX: 0000000000000004  RBX: fffffffffffffff4  RCX: 000000018020001f
    RDX: ffff880830997fc0  RSI: 0000000000000001  RDI: ffff88085f407200
    RBP: ffff88084d323778   R8: 0000000000000001   R9: ffffea0020bae210
    R10: ffffea0020bae218  R11: 0000000000000001  R12: ffff88084d3237c8
    R13: 00000000fffffff4  R14: ffff880859fa5000  R15: ffff88082eb89800
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
#10 [ffff88084d323780] rdma_create_qp at ffffffffa0782681 [rdma_cm]
#11 [ffff88084d3237b0] nvmet_rdma_create_queue_ib at ffffffffa07c43f3 [nvmet_rdma]
#12 [ffff88084d323860] nvmet_rdma_alloc_queue at ffffffffa07c5ba9 [nvmet_rdma]
#13 [ffff88084d323900] nvmet_rdma_queue_connect at ffffffffa07c5c96 [nvmet_rdma]
#14 [ffff88084d323980] nvmet_rdma_cm_handler at ffffffffa07c6450 [nvmet_rdma]
#15 [ffff88084d3239b0] iw_conn_req_handler at ffffffffa0787480 [rdma_cm]
#16 [ffff88084d323a60] cm_conn_req_handler at ffffffffa0775f06 [iw_cm]
#17 [ffff88084d323ab0] process_event at ffffffffa0776019 [iw_cm]
#18 [ffff88084d323af0] cm_work_handler at ffffffffa0776170 [iw_cm]
#19 [ffff88084d323cb0] process_one_work at ffffffff810a1483
#20 [ffff88084d323d90] worker_thread at ffffffff810a211d
#21 [ffff88084d323ec0] kthread at ffffffff810a6c5c
#22 [ffff88084d323f50] ret_from_fork at ffffffff816e1ebf

Fixes: 632bc3f ("IB/core, RDMA RW API: Do not exceed QP SGE send limit")
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
bgly pushed a commit that referenced this pull request Nov 30, 2016
BugLink: http://bugs.launchpad.net/bugs/1638748

commit 341d7eb upstream.

AP queue is properly released, but P2P queue isn't.

Fixes: commit 4c96513 ("iwlwifi: mvm: support p2p device frames tx on dqa queue #2")
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
bgly pushed a commit that referenced this pull request Nov 30, 2016
BugLink: http://bugs.launchpad.net/bugs/1645421

commit 1454ca3 upstream.

Missing initialization of udp_tunnel_sock_cfg causes to following
kernel panic, while kernel tries to execute gro_receive().

While being there, we converted udp_port_cfg to use the same
initialization scheme as udp_tunnel_sock_cfg.

------------[ cut here ]------------
kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle kernel paging request at ffffffffa0588c50
IP: [<ffffffffa0588c50>] __this_module+0x50/0xffffffffffff8400 [ib_rxe]
PGD 1c09067 PUD 1c0a063 PMD bb394067 PTE 80000000ad5e8163
Oops: 0011 [#1] SMP
Modules linked in: ib_rxe ip6_udp_tunnel udp_tunnel
CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.7.0-rc3+ #2
Hardware name: Red Hat KVM, BIOS Bochs 01/01/2011
task: ffff880235e4e680 ti: ffff880235e68000 task.ti: ffff880235e68000
RIP: 0010:[<ffffffffa0588c50>]
[<ffffffffa0588c50>] __this_module+0x50/0xffffffffffff8400 [ib_rxe]
RSP: 0018:ffff880237343c80  EFLAGS: 00010282
RAX: 00000000dffe482d RBX: ffff8800ae330900 RCX: 000000002001b712
RDX: ffff8800ae330900 RSI: ffff8800ae102578 RDI: ffff880235589c00
RBP: ffff880237343cb0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800ae33e262
R13: ffff880235589c00 R14: 0000000000000014 R15: ffff8800ae102578
FS:  0000000000000000(0000) GS:ffff880237340000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffa0588c50 CR3: 0000000001c06000 CR4: 00000000000006e0
Stack:
ffffffff8160860e ffff8800ae330900 ffff8800ae102578 0000000000000014
000000000000004e ffff8800ae102578 ffff880237343ce0 ffffffff816088fb
0000000000000000 ffff8800ae330900 0000000000000000 00000000ffad0000
Call Trace:
<IRQ>
[<ffffffff8160860e>] ? udp_gro_receive+0xde/0x130
[<ffffffff816088fb>] udp4_gro_receive+0x10b/0x2d0
[<ffffffff81611373>] inet_gro_receive+0x1d3/0x270
[<ffffffff81594e29>] dev_gro_receive+0x269/0x3b0
[<ffffffff81595188>] napi_gro_receive+0x38/0x120
[<ffffffffa011caee>] mlx5e_handle_rx_cqe+0x27e/0x340 [mlx5_core]
[<ffffffffa011d076>] mlx5e_poll_rx_cq+0x66/0x6d0 [mlx5_core]
[<ffffffffa011d7ae>] mlx5e_napi_poll+0x8e/0x400 [mlx5_core]
[<ffffffff815949a0>] net_rx_action+0x160/0x380
[<ffffffff816a9197>] __do_softirq+0xd7/0x2c5
[<ffffffff81085c35>] irq_exit+0xf5/0x100
[<ffffffff816a8f16>] do_IRQ+0x56/0xd0
[<ffffffff816a6dcc>] common_interrupt+0x8c/0x8c
<EOI>
[<ffffffff81061f96>] ? native_safe_halt+0x6/0x10
[<ffffffff81037ade>] default_idle+0x1e/0xd0
[<ffffffff8103828f>] arch_cpu_idle+0xf/0x20
[<ffffffff810c37dc>] default_idle_call+0x3c/0x50
[<ffffffff810c3b13>] cpu_startup_entry+0x323/0x3c0
[<ffffffff81050d8c>] start_secondary+0x15c/0x1a0
RIP  [<ffffffffa0588c50>] __this_module+0x50/0xffffffffffff8400 [ib_rxe]
RSP <ffff880237343c80>
CR2: ffffffffa0588c50
---[ end trace 489ee31fa7614ac5 ]---
Kernel panic - not syncing: Fatal exception in interrupt
Kernel Offset: disabled
---[ end Kernel panic - not syncing: Fatal exception in interrupt
------------[ cut here ]------------

Fixes: 8700e3e ("Soft RoCE driver")
Signed-off-by: Yonatan Cohen <yonatanc@mellanox.com>
Reviewed-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
bgly pushed a commit that referenced this pull request Jan 31, 2017
BugLink: http://bugs.launchpad.net/bugs/1629386

commit 7e95630 upstream.

In the mipsr2_decoder() function, used to emulate pre-MIPSr6
instructions that were removed in MIPSr6, the init_fpu() function is
called if a removed pre-MIPSr6 floating point instruction is the first
floating point instruction used by the task. However, init_fpu()
performs varous actions that rely upon not being migrated. For example
in the most basic case it sets the coprocessor 0 Status.CU1 bit to
enable the FPU & then loads FP register context into the FPU registers.
If the task were to migrate during this time, it may end up attempting
to load FP register context on a different CPU where it hasn't set the
CU1 bit, leading to errors such as:

    do_cpu invoked from kernel context![#2]:
    CPU: 2 PID: 7338 Comm: fp-prctl Tainted: G      D         4.7.0-00424-g49b0c82 #2
    task: 838e4000 ti: 88d38000 task.ti: 88d38000
    $ 0   : 00000000 00000001 ffffffff 88d3fef8
    $ 4   : 838e4000 88d38004 00000000 00000001
    $ 8   : 3400fc01 801f8020 808e9100 24000000
    $12   : dbffffff 807b69d8 807b0000 00000000
    $16   : 00000000 80786150 00400fc4 809c0398
    $20   : 809c0338 0040273c 88d3ff28 808e9d30
    $24   : 808e9d30 00400fb4
    $28   : 88d38000 88d3fe88 00000000 8011a2ac
    Hi    : 0040273c
    Lo    : 88d3ff28
    epc   : 80114178 _restore_fp+0x10/0xa0
    ra    : 8011a2ac mipsr2_decoder+0xd5c/0x1660
    Status: 1400fc03	KERNEL EXL IE
    Cause : 1080002c (ExcCode 0b)
    PrId  : 0001a920 (MIPS I6400)
    Modules linked in:
    Process fp-prctl (pid: 7338, threadinfo=88d38000, task=838e4000, tls=766527d0)
    Stack : 00000000 00000000 00000000 88d3fe98 00000000 00000000 809c0398 809c0338
    	  808e9100 00000000 88d3ff28 00400fc4 00400fc4 0040273c 7fb69e18 004a0000
    	  004a0000 004a0000 7664add0 8010de18 00000000 00000000 88d3fef8 88d3ff28
    	  808e9100 00000000 766527d0 8010e534 000c0000 85755000 8181d580 00000000
    	  00000000 00000000 004a0000 00000000 766527d0 7fb69e18 004a0000 80105c20
    	  ...
    Call Trace:
    [<80114178>] _restore_fp+0x10/0xa0
    [<8011a2ac>] mipsr2_decoder+0xd5c/0x1660
    [<8010de18>] do_ri+0x90/0x6b8
    [<80105c20>] ret_from_exception+0x0/0x10

Fix this by disabling preemption around the call to init_fpu(), ensuring
that it starts & completes on one CPU.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: b0a668f ("MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14305/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
bgly pushed a commit that referenced this pull request Jan 31, 2017
BugLink: http://bugs.launchpad.net/bugs/1631468

commit 61dc0a4 upstream.

pm_runtime_get_sync does return a error value that must be checked for
error conditions, else, due to various reasons, the device maynot be
enabled and the system will crash due to lack of clock to the hardware
module.

Before:
12.562784] [00000000] *pgd=fe193835
12.562792] Internal error: : 1406 [#1] SMP ARM
[...]
12.562864] CPU: 1 PID: 241 Comm: modprobe Not tainted 4.7.0-rc4-next-20160624 #2
12.562867] Hardware name: Generic DRA74X (Flattened Device Tree)
12.562872] task: ed51f140 ti: ed44c000 task.ti: ed44c000
12.562886] PC is at omap4_rng_init+0x20/0x84 [omap_rng]
12.562899] LR is at set_current_rng+0xc0/0x154 [rng_core]
[...]

After the proper checks:
[   94.366705] omap_rng 48090000.rng: _od_fail_runtime_resume: FIXME:
missing hwmod/omap_dev info
[   94.375767] omap_rng 48090000.rng: Failed to runtime_get device -19
[   94.382351] omap_rng 48090000.rng: initialization failed.

Fixes: 665d92f ("hwrng: OMAP: convert to use runtime PM")
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
bgly pushed a commit that referenced this pull request Jan 31, 2017
BugLink: http://bugs.launchpad.net/bugs/1637501

commit 420902c upstream.

If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can
deadlock our own worker - mount blocks kworker/3:2, sleeps forever more.

crash> ps|grep UN
    715      2   3  ffff880220734d30  UN   0.0       0      0  [kworker/3:2]
   9369   9341   2  ffff88021ffb7560  UN   1.3  493404 123184  Xorg
   9665   9664   3  ffff880225b92ab0  UN   0.0   47368    812  udisks-daemon
  10635  10403   3  ffff880222f22c70  UN   0.0   14904    936  mount
crash> bt ffff880220734d30
PID: 715    TASK: ffff880220734d30  CPU: 3   COMMAND: "kworker/3:2"
 #0 [ffff8802244c3c20] schedule at ffffffff8144584b
 #1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3
 #2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5
 #3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs]
 #4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs]
 #5 [ffff8802244c3e08] process_one_work at ffffffff81073726
 #6 [ffff8802244c3e68] worker_thread at ffffffff81073eba
 #7 [ffff8802244c3ec8] kthread at ffffffff810782e0
 #8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064
crash> rd ffff8802244c3cc8 10
ffff8802244c3cc8:  ffffffff814472b3 ffff880222f23250   .rD.....P2."....
ffff8802244c3cd8:  0000000000000000 0000000000000286   ................
ffff8802244c3ce8:  ffff8802244c3d30 ffff880220734d80   0=L$.....Ms ....
ffff8802244c3cf8:  ffff880222e8f628 0000000000000000   (.."............
ffff8802244c3d08:  0000000000000000 0000000000000002   ................
crash> struct rt_mutex ffff880222e8f628
struct rt_mutex {
  wait_lock = {
    raw_lock = {
      slock = 65537
    }
  },
  wait_list = {
    node_list = {
      next = 0xffff8802244c3d48,
      prev = 0xffff8802244c3d48
    }
  },
  owner = 0xffff880222f22c71,
  save_state = 0
}
crash> bt 0xffff880222f22c70
PID: 10635  TASK: ffff880222f22c70  CPU: 3   COMMAND: "mount"
 #0 [ffff8802216a9868] schedule at ffffffff8144584b
 #1 [ffff8802216a9910] schedule_timeout at ffffffff81446865
 #2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74
 #3 [ffff8802216a9a30] flush_work at ffffffff810712d3
 #4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463
 #5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba
 #6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632
 #7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c
 #8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs]
 #9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs]
    RIP: 00007f7b9303997a  RSP: 00007ffff443c7a8  RFLAGS: 00010202
    RAX: 00000000000000a5  RBX: ffffffff8144ef12  RCX: 00007f7b932e9ee0
    RDX: 00007f7b93d9a400  RSI: 00007f7b93d9a3e0  RDI: 00007f7b93d9a3c0
    RBP: 00007f7b93d9a2c0   R8: 00007f7b93d9a550   R9: 0000000000000001
    R10: ffffffffc0ed040e  R11: 0000000000000202  R12: 000000000000040e
    R13: 0000000000000000  R14: 00000000c0ed040e  R15: 00007ffff443ca20
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
bgly pushed a commit that referenced this pull request Jan 31, 2017
BugLink: http://bugs.launchpad.net/bugs/1658091

commit a545715 upstream.

When removing and adding cpu 0 on a system with GHES NMI the following stack
trace is seen when re-adding the cpu:

WARNING: CPU: 0 PID: 0 at arch/x86/kernel/apic/apic.c:1349 setup_local_APIC+
Modules linked in: nfsv3 rpcsec_gss_krb5 nfsv4 nfs fscache coretemp intel_ra
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc6+ #2
Call Trace:
 dump_stack+0x63/0x8e
 __warn+0xd1/0xf0
 warn_slowpath_null+0x1d/0x20
 setup_local_APIC+0x275/0x370
 apic_ap_setup+0xe/0x20
 start_secondary+0x48/0x180
 set_init_arg+0x55/0x55
 early_idt_handler_array+0x120/0x120
 x86_64_start_reservations+0x2a/0x2c
 x86_64_start_kernel+0x13d/0x14c

During the cpu bringup, wakeup_cpu_via_init_nmi() is called and issues an
NMI on CPU 0.  The GHES NMI handler, ghes_notify_nmi() runs the
ghes_proc_irq_work work queue which ends up setting IRQ_WORK_VECTOR
(0xf6).  The "faulty" IR line set at arch/x86/kernel/apic/apic.c:1349 is  also
0xf6 (specifically APIC IRR for irqs 255 to 224 is 0x400000) which confirms
that something has set the IRQ_WORK_VECTOR line prior to the APIC being
initialized.

Commit 2383844 ("GHES: Elliminate double-loop in the NMI handler")
incorrectly modified the behavior such that the handler returns
NMI_HANDLED only if an error was processed, and incorrectly runs the ghes
work queue for every NMI.

This patch modifies the ghes_proc_irq_work() to run as it did prior to
2383844 ("GHES: Elliminate double-loop in the NMI handler") by
properly returning NMI_HANDLED and only calling the work queue if
NMI_HANDLED has been set.

Fixes: 2383844 (GHES: Elliminate double-loop in the NMI handler)
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
bgly pushed a commit that referenced this pull request Aug 18, 2017
BugLink: http://bugs.launchpad.net/bugs/1669016

[ Upstream commit 2bd624b ]

Commit 6664498 ("packet: call fanout_release, while UNREGISTERING a
netdev"), unfortunately, introduced the following issues.

1. calling mutex_lock(&fanout_mutex) (fanout_release()) from inside
rcu_read-side critical section. rcu_read_lock disables preemption, most often,
which prohibits calling sleeping functions.

[  ] include/linux/rcupdate.h:560 Illegal context switch in RCU read-side critical section!
[  ]
[  ] rcu_scheduler_active = 1, debug_locks = 0
[  ] 4 locks held by ovs-vswitchd/1969:
[  ]  #0:  (cb_lock){++++++}, at: [<ffffffff8158a6c9>] genl_rcv+0x19/0x40
[  ]  #1:  (ovs_mutex){+.+.+.}, at: [<ffffffffa04878ca>] ovs_vport_cmd_del+0x4a/0x100 [openvswitch]
[  ]  #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff81564157>] rtnl_lock+0x17/0x20
[  ]  #3:  (rcu_read_lock){......}, at: [<ffffffff81614165>] packet_notifier+0x5/0x3f0
[  ]
[  ] Call Trace:
[  ]  [<ffffffff813770c1>] dump_stack+0x85/0xc4
[  ]  [<ffffffff810c9077>] lockdep_rcu_suspicious+0x107/0x110
[  ]  [<ffffffff810a2da7>] ___might_sleep+0x57/0x210
[  ]  [<ffffffff810a2fd0>] __might_sleep+0x70/0x90
[  ]  [<ffffffff8162e80c>] mutex_lock_nested+0x3c/0x3a0
[  ]  [<ffffffff810de93f>] ? vprintk_default+0x1f/0x30
[  ]  [<ffffffff81186e88>] ? printk+0x4d/0x4f
[  ]  [<ffffffff816106dd>] fanout_release+0x1d/0xe0
[  ]  [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0

2. calling mutex_lock(&fanout_mutex) inside spin_lock(&po->bind_lock).
"sleeping function called from invalid context"

[  ] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[  ] in_atomic(): 1, irqs_disabled(): 0, pid: 1969, name: ovs-vswitchd
[  ] INFO: lockdep is turned off.
[  ] Call Trace:
[  ]  [<ffffffff813770c1>] dump_stack+0x85/0xc4
[  ]  [<ffffffff810a2f52>] ___might_sleep+0x202/0x210
[  ]  [<ffffffff810a2fd0>] __might_sleep+0x70/0x90
[  ]  [<ffffffff8162e80c>] mutex_lock_nested+0x3c/0x3a0
[  ]  [<ffffffff816106dd>] fanout_release+0x1d/0xe0
[  ]  [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0

3. calling dev_remove_pack(&fanout->prot_hook), from inside
spin_lock(&po->bind_lock) or rcu_read-side critical-section. dev_remove_pack()
-> synchronize_net(), which might sleep.

[  ] BUG: scheduling while atomic: ovs-vswitchd/1969/0x00000002
[  ] INFO: lockdep is turned off.
[  ] Call Trace:
[  ]  [<ffffffff813770c1>] dump_stack+0x85/0xc4
[  ]  [<ffffffff81186274>] __schedule_bug+0x64/0x73
[  ]  [<ffffffff8162b8cb>] __schedule+0x6b/0xd10
[  ]  [<ffffffff8162c5db>] schedule+0x6b/0x80
[  ]  [<ffffffff81630b1d>] schedule_timeout+0x38d/0x410
[  ]  [<ffffffff810ea3fd>] synchronize_sched_expedited+0x53d/0x810
[  ]  [<ffffffff810ea6de>] synchronize_rcu_expedited+0xe/0x10
[  ]  [<ffffffff8154eab5>] synchronize_net+0x35/0x50
[  ]  [<ffffffff8154eae3>] dev_remove_pack+0x13/0x20
[  ]  [<ffffffff8161077e>] fanout_release+0xbe/0xe0
[  ]  [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0

4. fanout_release() races with calls from different CPU.

To fix the above problems, remove the call to fanout_release() under
rcu_read_lock(). Instead, call __dev_remove_pack(&fanout->prot_hook) and
netdev_run_todo will be happy that &dev->ptype_specific list is empty. In order
to achieve this, I moved dev_{add,remove}_pack() out of fanout_{add,release} to
__fanout_{link,unlink}. So, call to {,__}unregister_prot_hook() will make sure
fanout->prot_hook is removed as well.

Fixes: 6664498 ("packet: call fanout_release, while UNREGISTERING a netdev")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Anoob Soman <anoob.soman@citrix.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
bgly pushed a commit that referenced this pull request Aug 18, 2017
BugLink: http://bugs.launchpad.net/bugs/1675789

[ Upstream commit d5afb6f ]

The code where sk_clone() came from created a new socket and locked it,
but then, on the error path didn't unlock it.

This problem stayed there for a long while, till b0691c8 ("net:
Unlock sock before calling sk_free()") fixed it, but unfortunately the
callers of sk_clone() (now sk_clone_locked()) were not audited and the
one in dccp_create_openreq_child() remained.

Now in the age of the syskaller fuzzer, this was finally uncovered, as
reported by Dmitry:

 ---- 8< ----

I've got the following report while running syzkaller fuzzer on
86292b3 ("Merge branch 'akpm' (patches from Andrew)")

  [ BUG: held lock freed! ]
  4.10.0+ torvalds#234 Not tainted
  -------------------------
  syz-executor6/6898 is freeing memory
  ffff88006286cac0-ffff88006286d3b7, with a lock still held there!
   (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock
  include/linux/spinlock.h:299 [inline]
   (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>]
  sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504
  5 locks held by syz-executor6/6898:
   #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] lock_sock
  include/net/sock.h:1460 [inline]
   #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>]
  inet_stream_connect+0x44/0xa0 net/ipv4/af_inet.c:681
   #1:  (rcu_read_lock){......}, at: [<ffffffff83bc1c2a>]
  inet6_csk_xmit+0x12a/0x5d0 net/ipv6/inet6_connection_sock.c:126
   #2:  (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_unlink
  include/linux/skbuff.h:1767 [inline]
   #2:  (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_dequeue
  include/linux/skbuff.h:1783 [inline]
   #2:  (rcu_read_lock){......}, at: [<ffffffff8369b424>]
  process_backlog+0x264/0x730 net/core/dev.c:4835
   #3:  (rcu_read_lock){......}, at: [<ffffffff83aeb5c0>]
  ip6_input_finish+0x0/0x1700 net/ipv6/ip6_input.c:59
   #4:  (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock
  include/linux/spinlock.h:299 [inline]
   #4:  (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>]
  sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504

Fix it just like was done by b0691c8 ("net: Unlock sock before calling
sk_free()").

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170301153510.GE15145@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
bgly pushed a commit that referenced this pull request Aug 18, 2017
…e_pmd()

BugLink: http://bugs.launchpad.net/bugs/1681862

commit c9d398f upstream.

I found the race condition which triggers the following bug when
move_pages() and soft offline are called on a single hugetlb page
concurrently.

    Soft offlining page 0x119400 at 0x700000000000
    BUG: unable to handle kernel paging request at ffffea0011943820
    IP: follow_huge_pmd+0x143/0x190
    PGD 7ffd2067
    PUD 7ffd1067
    PMD 0
        [61163.582052] Oops: 0000 [#1] SMP
    Modules linked in: binfmt_misc ppdev virtio_balloon parport_pc pcspkr i2c_piix4 parport i2c_core acpi_cpufreq ip_tables xfs libcrc32c ata_generic pata_acpi virtio_blk 8139too crc32c_intel ata_piix serio_raw libata virtio_pci 8139cp virtio_ring virtio mii floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: cap_check]
    CPU: 0 PID: 22573 Comm: iterate_numa_mo Tainted: P           OE   4.11.0-rc2-mm1+ #2
    Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
    RIP: 0010:follow_huge_pmd+0x143/0x190
    RSP: 0018:ffffc90004bdbcd0 EFLAGS: 00010202
    RAX: 0000000465003e80 RBX: ffffea0004e34d30 RCX: 00003ffffffff000
    RDX: 0000000011943800 RSI: 0000000000080001 RDI: 0000000465003e80
    RBP: ffffc90004bdbd18 R08: 0000000000000000 R09: ffff880138d34000
    R10: ffffea0004650000 R11: 0000000000c363b0 R12: ffffea0011943800
    R13: ffff8801b8d34000 R14: ffffea0000000000 R15: 000077ff80000000
    FS:  00007fc977710740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: ffffea0011943820 CR3: 000000007a746000 CR4: 00000000001406f0
    Call Trace:
     follow_page_mask+0x270/0x550
     SYSC_move_pages+0x4ea/0x8f0
     SyS_move_pages+0xe/0x10
     do_syscall_64+0x67/0x180
     entry_SYSCALL64_slow_path+0x25/0x25
    RIP: 0033:0x7fc976e03949
    RSP: 002b:00007ffe72221d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000117
    RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc976e03949
    RDX: 0000000000c22390 RSI: 0000000000001400 RDI: 0000000000005827
    RBP: 00007ffe72221e00 R08: 0000000000c2c3a0 R09: 0000000000000004
    R10: 0000000000c363b0 R11: 0000000000000246 R12: 0000000000400650
    R13: 00007ffe72221ee0 R14: 0000000000000000 R15: 0000000000000000
    Code: 81 e4 ff ff 1f 00 48 21 c2 49 c1 ec 0c 48 c1 ea 0c 4c 01 e2 49 bc 00 00 00 00 00 ea ff ff 48 c1 e2 06 49 01 d4 f6 45 bc 04 74 90 <49> 8b 7c 24 20 40 f6 c7 01 75 2b 4c 89 e7 8b 47 1c 85 c0 7e 2a
    RIP: follow_huge_pmd+0x143/0x190 RSP: ffffc90004bdbcd0
    CR2: ffffea0011943820
    ---[ end trace e4f81353a2d23232 ]---
    Kernel panic - not syncing: Fatal exception
    Kernel Offset: disabled

This bug is triggered when pmd_present() returns true for non-present
hugetlb, so fixing the present check in follow_huge_pmd() prevents it.
Using pmd_present() to determine present/non-present for hugetlb is not
correct, because pmd_present() checks multiple bits (not only
_PAGE_PRESENT) for historical reason and it can misjudge hugetlb state.

Fixes: e66f17f ("mm/hugetlb: take page table lock in follow_huge_pmd()")
Link: http://lkml.kernel.org/r/1490149898-20231-1-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
bgly pushed a commit that referenced this pull request Aug 18, 2017
BugLink: http://bugs.launchpad.net/bugs/1687629

commit 0beb201 upstream.

Holding the reconfig_mutex over a potential userspace fault sets up a
lockdep dependency chain between filesystem-DAX and the libnvdimm ioctl
path. Move the user access outside of the lock.

     [ INFO: possible circular locking dependency detected ]
     4.11.0-rc3+ #13 Tainted: G        W  O
     -------------------------------------------------------
     fallocate/16656 is trying to acquire lock:
      (&nvdimm_bus->reconfig_mutex){+.+.+.}, at: [<ffffffffa00080b1>] nvdimm_bus_lock+0x21/0x30 [libnvdimm]
     but task is already holding lock:
      (jbd2_handle){++++..}, at: [<ffffffff813b4944>] start_this_handle+0x104/0x460

    which lock already depends on the new lock.

    the existing dependency chain (in reverse order) is:

    -> #2 (jbd2_handle){++++..}:
            lock_acquire+0xbd/0x200
            start_this_handle+0x16a/0x460
            jbd2__journal_start+0xe9/0x2d0
            __ext4_journal_start_sb+0x89/0x1c0
            ext4_dirty_inode+0x32/0x70
            __mark_inode_dirty+0x235/0x670
            generic_update_time+0x87/0xd0
            touch_atime+0xa9/0xd0
            ext4_file_mmap+0x90/0xb0
            mmap_region+0x370/0x5b0
            do_mmap+0x415/0x4f0
            vm_mmap_pgoff+0xd7/0x120
            SyS_mmap_pgoff+0x1c5/0x290
            SyS_mmap+0x22/0x30
            entry_SYSCALL_64_fastpath+0x1f/0xc2

    -> #1 (&mm->mmap_sem){++++++}:
            lock_acquire+0xbd/0x200
            __might_fault+0x70/0xa0
            __nd_ioctl+0x683/0x720 [libnvdimm]
            nvdimm_ioctl+0x8b/0xe0 [libnvdimm]
            do_vfs_ioctl+0xa8/0x740
            SyS_ioctl+0x79/0x90
            do_syscall_64+0x6c/0x200
            return_from_SYSCALL_64+0x0/0x7a

    -> #0 (&nvdimm_bus->reconfig_mutex){+.+.+.}:
            __lock_acquire+0x16b6/0x1730
            lock_acquire+0xbd/0x200
            __mutex_lock+0x88/0x9b0
            mutex_lock_nested+0x1b/0x20
            nvdimm_bus_lock+0x21/0x30 [libnvdimm]
            nvdimm_forget_poison+0x25/0x50 [libnvdimm]
            nvdimm_clear_poison+0x106/0x140 [libnvdimm]
            pmem_do_bvec+0x1c2/0x2b0 [nd_pmem]
            pmem_make_request+0xf9/0x270 [nd_pmem]
            generic_make_request+0x118/0x3b0
            submit_bio+0x75/0x150

Fixes: 62232e4 ("libnvdimm: control (ioctl) messages for nvdimm_bus and nvdimm devices")
Cc: Dave Jiang <dave.jiang@intel.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
bgly pushed a commit that referenced this pull request Aug 18, 2017
BugLink: http://bugs.launchpad.net/bugs/1691418

[ Upstream commit ddc665a ]

When the instruction right before the branch destination is
a 64 bit load immediate, we currently calculate the wrong
jump offset in the ctx->offset[] array as we only account
one instruction slot for the 64 bit load immediate although
it uses two BPF instructions. Fix it up by setting the offset
into the right slot after we incremented the index.

Before (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // #3
  00000028:  d2800041  mov x1, #0x2 // #2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  54ffff82  b.cs 0x00000020
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl torvalds#48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl torvalds#48
  [...]

After (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // #3
  00000028:  d2800041  mov x1, #0x2 // #2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  540000a2  b.cs 0x00000044
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl torvalds#48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl torvalds#48
  [...]

Also, add a couple of test cases to make sure JITs pass
this test. Tested on Cavium ThunderX ARMv8. The added
test cases all pass after the fix.

Fixes: 8eee539 ("arm64: bpf: fix out-of-bounds read in bpf2a64_offset()")
Reported-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Xi Wang <xi.wang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
bgly pushed a commit that referenced this pull request Aug 23, 2017
commit 978d13d upstream.

This patch fixes a bug associated with iscsit_reset_np_thread()
that can occur during parallel configfs rmdir of a single iscsi_np
used across multiple iscsi-target instances, that would result in
hung task(s) similar to below where configfs rmdir process context
was blocked indefinately waiting for iscsi_np->np_restart_comp
to finish:

[ 6726.112076] INFO: task dcp_proxy_node_:15550 blocked for more than 120 seconds.
[ 6726.119440]       Tainted: G        W  O     4.1.26-3321 #2
[ 6726.125045] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6726.132927] dcp_proxy_node_ D ffff8803f202bc88     0 15550      1 0x00000000
[ 6726.140058]  ffff8803f202bc88 ffff88085c64d960 ffff88083b3b1ad0 ffff88087fffeb08
[ 6726.147593]  ffff8803f202c000 7fffffffffffffff ffff88083f459c28 ffff88083b3b1ad0
[ 6726.155132]  ffff88035373c100 ffff8803f202bca8 ffffffff8168ced2 ffff8803f202bcb8
[ 6726.162667] Call Trace:
[ 6726.165150]  [<ffffffff8168ced2>] schedule+0x32/0x80
[ 6726.170156]  [<ffffffff8168f5b4>] schedule_timeout+0x214/0x290
[ 6726.176030]  [<ffffffff810caef2>] ? __send_signal+0x52/0x4a0
[ 6726.181728]  [<ffffffff8168d7d6>] wait_for_completion+0x96/0x100
[ 6726.187774]  [<ffffffff810e7c80>] ? wake_up_state+0x10/0x10
[ 6726.193395]  [<ffffffffa035d6e2>] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod]
[ 6726.201278]  [<ffffffffa0355d86>] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod]
[ 6726.210033]  [<ffffffffa0363f7f>] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod]
[ 6726.218351]  [<ffffffff81260c5a>] configfs_write_file+0xaa/0x110
[ 6726.224392]  [<ffffffff811ea364>] vfs_write+0xa4/0x1b0
[ 6726.229576]  [<ffffffff811eb111>] SyS_write+0x41/0xb0
[ 6726.234659]  [<ffffffff8169042e>] system_call_fastpath+0x12/0x71

It would happen because each iscsit_reset_np_thread() sets state
to ISCSI_NP_THREAD_RESET, sends SIGINT, and then blocks waiting
for completion on iscsi_np->np_restart_comp.

However, if iscsi_np was active processing a login request and
more than a single iscsit_reset_np_thread() caller to the same
iscsi_np was blocked on iscsi_np->np_restart_comp, iscsi_np
kthread process context in __iscsi_target_login_thread() would
flush pending signals and only perform a single completion of
np->np_restart_comp before going back to sleep within transport
specific iscsit_transport->iscsi_accept_np code.

To address this bug, add a iscsi_np->np_reset_count and update
__iscsi_target_login_thread() to keep completing np->np_restart_comp
until ->np_reset_count has reached zero.

Reported-by: Gary Guo <ghg@datera.io>
Tested-by: Gary Guo <ghg@datera.io>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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