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fix segmentation fault of modpost #3

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mitake opened this issue Jun 30, 2012 · 0 comments
Open

fix segmentation fault of modpost #3

mitake opened this issue Jun 30, 2012 · 0 comments

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@mitake
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mitake commented Jun 30, 2012

http://lkml.org/lkml/2012/2/22/39

mitake pushed a commit that referenced this issue Sep 11, 2012
commit 5d299f3 (net: ipv6: fix TCP early demux) added a
regression for ipv6_mapped case.

[   67.422369] SELinux: initialized (dev autofs, type autofs), uses
genfs_contexts
[   67.449678] SELinux: initialized (dev autofs, type autofs), uses
genfs_contexts
[   92.631060] BUG: unable to handle kernel NULL pointer dereference at
(null)
[   92.631435] IP: [<          (null)>]           (null)
[   92.631645] PGD 0
[   92.631846] Oops: 0010 [#1] SMP
[   92.632095] Modules linked in: autofs4 sunrpc ipv6 dm_mirror
dm_region_hash dm_log dm_multipath dm_mod video sbs sbshc battery ac lp
parport sg snd_hda_intel snd_hda_codec snd_seq_oss snd_seq_midi_event
snd_seq snd_seq_device pcspkr snd_pcm_oss snd_mixer_oss snd_pcm
snd_timer serio_raw button floppy snd i2c_i801 i2c_core soundcore
snd_page_alloc shpchp ide_cd_mod cdrom microcode ehci_hcd ohci_hcd
uhci_hcd
[   92.634294] CPU 0
[   92.634294] Pid: 4469, comm: sendmail Not tainted 3.6.0-rc1 #3
[   92.634294] RIP: 0010:[<0000000000000000>]  [<          (null)>]
(null)
[   92.634294] RSP: 0018:ffff880245fc7cb0  EFLAGS: 00010282
[   92.634294] RAX: ffffffffa01985f0 RBX: ffff88024827ad00 RCX:
0000000000000000
[   92.634294] RDX: 0000000000000218 RSI: ffff880254735380 RDI:
ffff88024827ad00
[   92.634294] RBP: ffff880245fc7cc8 R08: 0000000000000001 R09:
0000000000000000
[   92.634294] R10: 0000000000000000 R11: ffff880245fc7bf8 R12:
ffff880254735380
[   92.634294] R13: ffff880254735380 R14: 0000000000000000 R15:
7fffffffffff0218
[   92.634294] FS:  00007f4516ccd6f0(0000) GS:ffff880256600000(0000)
knlGS:0000000000000000
[   92.634294] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   92.634294] CR2: 0000000000000000 CR3: 0000000245ed1000 CR4:
00000000000007f0
[   92.634294] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[   92.634294] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
0000000000000400
[   92.634294] Process sendmail (pid: 4469, threadinfo ffff880245fc6000,
task ffff880254b8cac0)
[   92.634294] Stack:
[   92.634294]  ffffffff813837a7 ffff88024827ad00 ffff880254b6b0e8
ffff880245fc7d68
[   92.634294]  ffffffff81385083 00000000001d2680 ffff8802547353a8
ffff880245fc7d18
[   92.634294]  ffffffff8105903a ffff88024827ad60 0000000000000002
00000000000000ff
[   92.634294] Call Trace:
[   92.634294]  [<ffffffff813837a7>] ? tcp_finish_connect+0x2c/0xfa
[   92.634294]  [<ffffffff81385083>] tcp_rcv_state_process+0x2b6/0x9c6
[   92.634294]  [<ffffffff8105903a>] ? sched_clock_cpu+0xc3/0xd1
[   92.634294]  [<ffffffff81059073>] ? local_clock+0x2b/0x3c
[   92.634294]  [<ffffffff8138caf3>] tcp_v4_do_rcv+0x63a/0x670
[   92.634294]  [<ffffffff8133278e>] release_sock+0x128/0x1bd
[   92.634294]  [<ffffffff8139f060>] __inet_stream_connect+0x1b1/0x352
[   92.634294]  [<ffffffff813325f5>] ? lock_sock_nested+0x74/0x7f
[   92.634294]  [<ffffffff8104b333>] ? wake_up_bit+0x25/0x25
[   92.634294]  [<ffffffff813325f5>] ? lock_sock_nested+0x74/0x7f
[   92.634294]  [<ffffffff8139f223>] ? inet_stream_connect+0x22/0x4b
[   92.634294]  [<ffffffff8139f234>] inet_stream_connect+0x33/0x4b
[   92.634294]  [<ffffffff8132e8cf>] sys_connect+0x78/0x9e
[   92.634294]  [<ffffffff813fd407>] ? sysret_check+0x1b/0x56
[   92.634294]  [<ffffffff81088503>] ? __audit_syscall_entry+0x195/0x1c8
[   92.634294]  [<ffffffff811cc26e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[   92.634294]  [<ffffffff813fd3e2>] system_call_fastpath+0x16/0x1b
[   92.634294] Code:  Bad RIP value.
[   92.634294] RIP  [<          (null)>]           (null)
[   92.634294]  RSP <ffff880245fc7cb0>
[   92.634294] CR2: 0000000000000000
[   92.648982] ---[ end trace 24e2bed94314c8d9 ]---
[   92.649146] Kernel panic - not syncing: Fatal exception in interrupt

Fix this using inet_sk_rx_dst_set(), and export this function in case
IPv6 is modular.

Reported-by: Andrew Morton <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
mitake pushed a commit that referenced this issue Sep 11, 2012
On architectures where cputime_t is 64 bit type, is possible to trigger
divide by zero on do_div(temp, (__force u32) total) line, if total is a
non zero number but has lower 32 bit's zeroed. Removing casting is not
a good solution since some do_div() implementations do cast to u32
internally.

This problem can be triggered in practice on very long lived processes:

  PID: 2331   TASK: ffff880472814b00  CPU: 2   COMMAND: "oraagent.bin"
   #0 [ffff880472a51b70] machine_kexec at ffffffff8103214b
   #1 [ffff880472a51bd0] crash_kexec at ffffffff810b91c2
   #2 [ffff880472a51ca0] oops_end at ffffffff814f0b00
   #3 [ffff880472a51cd0] die at ffffffff8100f26b
   #4 [ffff880472a51d00] do_trap at ffffffff814f03f4
   #5 [ffff880472a51d60] do_divide_error at ffffffff8100cfff
   torvalds#6 [ffff880472a51e00] divide_error at ffffffff8100be7b
      [exception RIP: thread_group_times+0x56]
      RIP: ffffffff81056a16  RSP: ffff880472a51eb8  RFLAGS: 00010046
      RAX: bc3572c9fe12d194  RBX: ffff880874150800  RCX: 0000000110266fad
      RDX: 0000000000000000  RSI: ffff880472a51eb8  RDI: 001038ae7d9633dc
      RBP: ffff880472a51ef8   R8: 00000000b10a3a64   R9: ffff880874150800
      R10: 00007fcba27ab680  R11: 0000000000000202  R12: ffff880472a51f08
      R13: ffff880472a51f10  R14: 0000000000000000  R15: 0000000000000007
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
   torvalds#7 [ffff880472a51f00] do_sys_times at ffffffff8108845d
   torvalds#8 [ffff880472a51f40] sys_times at ffffffff81088524
   torvalds#9 [ffff880472a51f80] system_call_fastpath at ffffffff8100b0f2
      RIP: 0000003808caac3a  RSP: 00007fcba27ab6d8  RFLAGS: 00000202
      RAX: 0000000000000064  RBX: ffffffff8100b0f2  RCX: 0000000000000000
      RDX: 00007fcba27ab6e0  RSI: 000000000076d58e  RDI: 00007fcba27ab6e0
      RBP: 00007fcba27ab700   R8: 0000000000000020   R9: 000000000000091b
      R10: 00007fcba27ab680  R11: 0000000000000202  R12: 00007fff9ca41940
      R13: 0000000000000000  R14: 00007fcba27ac9c0  R15: 00007fff9ca41940
      ORIG_RAX: 0000000000000064  CS: 0033  SS: 002b

Cc: [email protected]
Signed-off-by: Stanislaw Gruszka <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>
mitake pushed a commit that referenced this issue Sep 11, 2012
The ZTE (Vodafone) K5006-Z use the following
interface layout:

00 DIAG
01 secondary
02 modem
03 networkcard
04 storage

Ignoring interface #3 which is handled by the qmi_wwan
driver.

Cc: Thomas Schäfer <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mitake pushed a commit that referenced this issue Sep 11, 2012
Commit 6f458df (tcp: improve latencies of timer triggered events)
added bug leading to following trace :

[ 2866.131281] IPv4: Attempt to release TCP socket in state 1 ffff880019ec0000
[ 2866.131726]
[ 2866.132188] =========================
[ 2866.132281] [ BUG: held lock freed! ]
[ 2866.132281] 3.6.0-rc1+ torvalds#622 Not tainted
[ 2866.132281] -------------------------
[ 2866.132281] kworker/0:1/652 is freeing memory ffff880019ec0000-ffff880019ec0a1f, with a lock still held there!
[ 2866.132281]  (sk_lock-AF_INET-RPC){+.+...}, at: [<ffffffff81903619>] tcp_sendmsg+0x29/0xcc6
[ 2866.132281] 4 locks held by kworker/0:1/652:
[ 2866.132281]  #0:  (rpciod){.+.+.+}, at: [<ffffffff81083567>] process_one_work+0x1de/0x47f
[ 2866.132281]  #1:  ((&task->u.tk_work)){+.+.+.}, at: [<ffffffff81083567>] process_one_work+0x1de/0x47f
[ 2866.132281]  #2:  (sk_lock-AF_INET-RPC){+.+...}, at: [<ffffffff81903619>] tcp_sendmsg+0x29/0xcc6
[ 2866.132281]  #3:  (&icsk->icsk_retransmit_timer){+.-...}, at: [<ffffffff81078017>] run_timer_softirq+0x1ad/0x35f
[ 2866.132281]
[ 2866.132281] stack backtrace:
[ 2866.132281] Pid: 652, comm: kworker/0:1 Not tainted 3.6.0-rc1+ torvalds#622
[ 2866.132281] Call Trace:
[ 2866.132281]  <IRQ>  [<ffffffff810bc527>] debug_check_no_locks_freed+0x112/0x159
[ 2866.132281]  [<ffffffff818a0839>] ? __sk_free+0xfd/0x114
[ 2866.132281]  [<ffffffff811549fa>] kmem_cache_free+0x6b/0x13a
[ 2866.132281]  [<ffffffff818a0839>] __sk_free+0xfd/0x114
[ 2866.132281]  [<ffffffff818a08c0>] sk_free+0x1c/0x1e
[ 2866.132281]  [<ffffffff81911e1c>] tcp_write_timer+0x51/0x56
[ 2866.132281]  [<ffffffff81078082>] run_timer_softirq+0x218/0x35f
[ 2866.132281]  [<ffffffff81078017>] ? run_timer_softirq+0x1ad/0x35f
[ 2866.132281]  [<ffffffff810f5831>] ? rb_commit+0x58/0x85
[ 2866.132281]  [<ffffffff81911dcb>] ? tcp_write_timer_handler+0x148/0x148
[ 2866.132281]  [<ffffffff81070bd6>] __do_softirq+0xcb/0x1f9
[ 2866.132281]  [<ffffffff81a0a00c>] ? _raw_spin_unlock+0x29/0x2e
[ 2866.132281]  [<ffffffff81a1227c>] call_softirq+0x1c/0x30
[ 2866.132281]  [<ffffffff81039f38>] do_softirq+0x4a/0xa6
[ 2866.132281]  [<ffffffff81070f2b>] irq_exit+0x51/0xad
[ 2866.132281]  [<ffffffff81a129cd>] do_IRQ+0x9d/0xb4
[ 2866.132281]  [<ffffffff81a0a3ef>] common_interrupt+0x6f/0x6f
[ 2866.132281]  <EOI>  [<ffffffff8109d006>] ? sched_clock_cpu+0x58/0xd1
[ 2866.132281]  [<ffffffff81a0a172>] ? _raw_spin_unlock_irqrestore+0x4c/0x56
[ 2866.132281]  [<ffffffff81078692>] mod_timer+0x178/0x1a9
[ 2866.132281]  [<ffffffff818a00aa>] sk_reset_timer+0x19/0x26
[ 2866.132281]  [<ffffffff8190b2cc>] tcp_rearm_rto+0x99/0xa4
[ 2866.132281]  [<ffffffff8190dfba>] tcp_event_new_data_sent+0x6e/0x70
[ 2866.132281]  [<ffffffff8190f7ea>] tcp_write_xmit+0x7de/0x8e4
[ 2866.132281]  [<ffffffff818a565d>] ? __alloc_skb+0xa0/0x1a1
[ 2866.132281]  [<ffffffff8190f952>] __tcp_push_pending_frames+0x2e/0x8a
[ 2866.132281]  [<ffffffff81904122>] tcp_sendmsg+0xb32/0xcc6
[ 2866.132281]  [<ffffffff819229c2>] inet_sendmsg+0xaa/0xd5
[ 2866.132281]  [<ffffffff81922918>] ? inet_autobind+0x5f/0x5f
[ 2866.132281]  [<ffffffff810ee7f1>] ? trace_clock_local+0x9/0xb
[ 2866.132281]  [<ffffffff8189adab>] sock_sendmsg+0xa3/0xc4
[ 2866.132281]  [<ffffffff810f5de6>] ? rb_reserve_next_event+0x26f/0x2d5
[ 2866.132281]  [<ffffffff8103e6a9>] ? native_sched_clock+0x29/0x6f
[ 2866.132281]  [<ffffffff8103e6f8>] ? sched_clock+0x9/0xd
[ 2866.132281]  [<ffffffff810ee7f1>] ? trace_clock_local+0x9/0xb
[ 2866.132281]  [<ffffffff8189ae03>] kernel_sendmsg+0x37/0x43
[ 2866.132281]  [<ffffffff8199ce49>] xs_send_kvec+0x77/0x80
[ 2866.132281]  [<ffffffff8199cec1>] xs_sendpages+0x6f/0x1a0
[ 2866.132281]  [<ffffffff8107826d>] ? try_to_del_timer_sync+0x55/0x61
[ 2866.132281]  [<ffffffff8199d0d2>] xs_tcp_send_request+0x55/0xf1
[ 2866.132281]  [<ffffffff8199bb90>] xprt_transmit+0x89/0x1db
[ 2866.132281]  [<ffffffff81999bcd>] ? call_connect+0x3c/0x3c
[ 2866.132281]  [<ffffffff81999d92>] call_transmit+0x1c5/0x20e
[ 2866.132281]  [<ffffffff819a0d55>] __rpc_execute+0x6f/0x225
[ 2866.132281]  [<ffffffff81999bcd>] ? call_connect+0x3c/0x3c
[ 2866.132281]  [<ffffffff819a0f33>] rpc_async_schedule+0x28/0x34
[ 2866.132281]  [<ffffffff810835d6>] process_one_work+0x24d/0x47f
[ 2866.132281]  [<ffffffff81083567>] ? process_one_work+0x1de/0x47f
[ 2866.132281]  [<ffffffff819a0f0b>] ? __rpc_execute+0x225/0x225
[ 2866.132281]  [<ffffffff81083a6d>] worker_thread+0x236/0x317
[ 2866.132281]  [<ffffffff81083837>] ? process_scheduled_works+0x2f/0x2f
[ 2866.132281]  [<ffffffff8108b7b8>] kthread+0x9a/0xa2
[ 2866.132281]  [<ffffffff81a12184>] kernel_thread_helper+0x4/0x10
[ 2866.132281]  [<ffffffff81a0a4b0>] ? retint_restore_args+0x13/0x13
[ 2866.132281]  [<ffffffff8108b71e>] ? __init_kthread_worker+0x5a/0x5a
[ 2866.132281]  [<ffffffff81a12180>] ? gs_change+0x13/0x13
[ 2866.308506] IPv4: Attempt to release TCP socket in state 1 ffff880019ec0000
[ 2866.309689] =============================================================================
[ 2866.310254] BUG TCP (Not tainted): Object already free
[ 2866.310254] -----------------------------------------------------------------------------
[ 2866.310254]

The bug comes from the fact that timer set in sk_reset_timer() can run
before we actually do the sock_hold(). socket refcount reaches zero and
we free the socket too soon.

timer handler is not allowed to reduce socket refcnt if socket is owned
by the user, or we need to change sk_reset_timer() implementation.

We should take a reference on the socket in case TCP_DELACK_TIMER_DEFERRED
or TCP_DELACK_TIMER_DEFERRED bit are set in tsq_flags

Also fix a typo in tcp_delack_timer(), where TCP_WRITE_TIMER_DEFERRED
was used instead of TCP_DELACK_TIMER_DEFERRED.

For consistency, use same socket refcount change for TCP_MTU_REDUCED_DEFERRED,
even if not fired from a timer.

Reported-by: Fengguang Wu <[email protected]>
Tested-by: Fengguang Wu <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
mitake pushed a commit that referenced this issue Oct 8, 2012
Fixes following lockdep splat :

[ 1614.734896] =============================================
[ 1614.734898] [ INFO: possible recursive locking detected ]
[ 1614.734901] 3.6.0-rc3+ torvalds#782 Not tainted
[ 1614.734903] ---------------------------------------------
[ 1614.734905] swapper/11/0 is trying to acquire lock:
[ 1614.734907]  (slock-AF_INET){+.-...}, at: [<ffffffffa0209d72>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
[ 1614.734920]
[ 1614.734920] but task is already holding lock:
[ 1614.734922]  (slock-AF_INET){+.-...}, at: [<ffffffff815fce23>] tcp_v4_err+0x163/0x6b0
[ 1614.734932]
[ 1614.734932] other info that might help us debug this:
[ 1614.734935]  Possible unsafe locking scenario:
[ 1614.734935]
[ 1614.734937]        CPU0
[ 1614.734938]        ----
[ 1614.734940]   lock(slock-AF_INET);
[ 1614.734943]   lock(slock-AF_INET);
[ 1614.734946]
[ 1614.734946]  *** DEADLOCK ***
[ 1614.734946]
[ 1614.734949]  May be due to missing lock nesting notation
[ 1614.734949]
[ 1614.734952] 7 locks held by swapper/11/0:
[ 1614.734954]  #0:  (rcu_read_lock){.+.+..}, at: [<ffffffff81592801>] __netif_receive_skb+0x251/0xd00
[ 1614.734964]  #1:  (rcu_read_lock){.+.+..}, at: [<ffffffff815d319c>] ip_local_deliver_finish+0x4c/0x4e0
[ 1614.734972]  #2:  (rcu_read_lock){.+.+..}, at: [<ffffffff8160d116>] icmp_socket_deliver+0x46/0x230
[ 1614.734982]  #3:  (slock-AF_INET){+.-...}, at: [<ffffffff815fce23>] tcp_v4_err+0x163/0x6b0
[ 1614.734989]  #4:  (rcu_read_lock){.+.+..}, at: [<ffffffff815da240>] ip_queue_xmit+0x0/0x680
[ 1614.734997]  #5:  (rcu_read_lock_bh){.+....}, at: [<ffffffff815d9925>] ip_finish_output+0x135/0x890
[ 1614.735004]  torvalds#6:  (rcu_read_lock_bh){.+....}, at: [<ffffffff81595680>] dev_queue_xmit+0x0/0xe00
[ 1614.735012]
[ 1614.735012] stack backtrace:
[ 1614.735016] Pid: 0, comm: swapper/11 Not tainted 3.6.0-rc3+ torvalds#782
[ 1614.735018] Call Trace:
[ 1614.735020]  <IRQ>  [<ffffffff810a50ac>] __lock_acquire+0x144c/0x1b10
[ 1614.735033]  [<ffffffff810a334b>] ? check_usage+0x9b/0x4d0
[ 1614.735037]  [<ffffffff810a6762>] ? mark_held_locks+0x82/0x130
[ 1614.735042]  [<ffffffff810a5df0>] lock_acquire+0x90/0x200
[ 1614.735047]  [<ffffffffa0209d72>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
[ 1614.735051]  [<ffffffff810a69ad>] ? trace_hardirqs_on+0xd/0x10
[ 1614.735060]  [<ffffffff81749b31>] _raw_spin_lock+0x41/0x50
[ 1614.735065]  [<ffffffffa0209d72>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
[ 1614.735069]  [<ffffffffa0209d72>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
[ 1614.735075]  [<ffffffffa014f7f2>] l2tp_eth_dev_xmit+0x32/0x60 [l2tp_eth]
[ 1614.735079]  [<ffffffff81595112>] dev_hard_start_xmit+0x502/0xa70
[ 1614.735083]  [<ffffffff81594c6e>] ? dev_hard_start_xmit+0x5e/0xa70
[ 1614.735087]  [<ffffffff815957c1>] ? dev_queue_xmit+0x141/0xe00
[ 1614.735093]  [<ffffffff815b622e>] sch_direct_xmit+0xfe/0x290
[ 1614.735098]  [<ffffffff81595865>] dev_queue_xmit+0x1e5/0xe00
[ 1614.735102]  [<ffffffff81595680>] ? dev_hard_start_xmit+0xa70/0xa70
[ 1614.735106]  [<ffffffff815b4daa>] ? eth_header+0x3a/0xf0
[ 1614.735111]  [<ffffffff8161d33e>] ? fib_get_table+0x2e/0x280
[ 1614.735117]  [<ffffffff8160a7e2>] arp_xmit+0x22/0x60
[ 1614.735121]  [<ffffffff8160a863>] arp_send+0x43/0x50
[ 1614.735125]  [<ffffffff8160b82f>] arp_solicit+0x18f/0x450
[ 1614.735132]  [<ffffffff8159d9da>] neigh_probe+0x4a/0x70
[ 1614.735137]  [<ffffffff815a191a>] __neigh_event_send+0xea/0x300
[ 1614.735141]  [<ffffffff815a1c93>] neigh_resolve_output+0x163/0x260
[ 1614.735146]  [<ffffffff815d9cf5>] ip_finish_output+0x505/0x890
[ 1614.735150]  [<ffffffff815d9925>] ? ip_finish_output+0x135/0x890
[ 1614.735154]  [<ffffffff815dae79>] ip_output+0x59/0xf0
[ 1614.735158]  [<ffffffff815da1cd>] ip_local_out+0x2d/0xa0
[ 1614.735162]  [<ffffffff815da403>] ip_queue_xmit+0x1c3/0x680
[ 1614.735165]  [<ffffffff815da240>] ? ip_local_out+0xa0/0xa0
[ 1614.735172]  [<ffffffff815f4402>] tcp_transmit_skb+0x402/0xa60
[ 1614.735177]  [<ffffffff815f5a11>] tcp_retransmit_skb+0x1a1/0x620
[ 1614.735181]  [<ffffffff815f7e93>] tcp_retransmit_timer+0x393/0x960
[ 1614.735185]  [<ffffffff815fce23>] ? tcp_v4_err+0x163/0x6b0
[ 1614.735189]  [<ffffffff815fd317>] tcp_v4_err+0x657/0x6b0
[ 1614.735194]  [<ffffffff8160d116>] ? icmp_socket_deliver+0x46/0x230
[ 1614.735199]  [<ffffffff8160d19e>] icmp_socket_deliver+0xce/0x230
[ 1614.735203]  [<ffffffff8160d116>] ? icmp_socket_deliver+0x46/0x230
[ 1614.735208]  [<ffffffff8160d464>] icmp_unreach+0xe4/0x2c0
[ 1614.735213]  [<ffffffff8160e520>] icmp_rcv+0x350/0x4a0
[ 1614.735217]  [<ffffffff815d3285>] ip_local_deliver_finish+0x135/0x4e0
[ 1614.735221]  [<ffffffff815d319c>] ? ip_local_deliver_finish+0x4c/0x4e0
[ 1614.735225]  [<ffffffff815d3ffa>] ip_local_deliver+0x4a/0x90
[ 1614.735229]  [<ffffffff815d37b7>] ip_rcv_finish+0x187/0x730
[ 1614.735233]  [<ffffffff815d425d>] ip_rcv+0x21d/0x300
[ 1614.735237]  [<ffffffff81592a1b>] __netif_receive_skb+0x46b/0xd00
[ 1614.735241]  [<ffffffff81592801>] ? __netif_receive_skb+0x251/0xd00
[ 1614.735245]  [<ffffffff81593368>] process_backlog+0xb8/0x180
[ 1614.735249]  [<ffffffff81593cf9>] net_rx_action+0x159/0x330
[ 1614.735257]  [<ffffffff810491f0>] __do_softirq+0xd0/0x3e0
[ 1614.735264]  [<ffffffff8109ed24>] ? tick_program_event+0x24/0x30
[ 1614.735270]  [<ffffffff8175419c>] call_softirq+0x1c/0x30
[ 1614.735278]  [<ffffffff8100425d>] do_softirq+0x8d/0xc0
[ 1614.735282]  [<ffffffff8104983e>] irq_exit+0xae/0xe0
[ 1614.735287]  [<ffffffff8175494e>] smp_apic_timer_interrupt+0x6e/0x99
[ 1614.735291]  [<ffffffff81753a1c>] apic_timer_interrupt+0x6c/0x80
[ 1614.735293]  <EOI>  [<ffffffff810a14ad>] ? trace_hardirqs_off+0xd/0x10
[ 1614.735306]  [<ffffffff81336f85>] ? intel_idle+0xf5/0x150
[ 1614.735310]  [<ffffffff81336f7e>] ? intel_idle+0xee/0x150
[ 1614.735317]  [<ffffffff814e6ea9>] cpuidle_enter+0x19/0x20
[ 1614.735321]  [<ffffffff814e7538>] cpuidle_idle_call+0xa8/0x630
[ 1614.735327]  [<ffffffff8100c1ba>] cpu_idle+0x8a/0xe0
[ 1614.735333]  [<ffffffff8173762e>] start_secondary+0x220/0x222

Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
mitake pushed a commit that referenced this issue Oct 8, 2012
busy_worker_rebind_fn() didn't clear WORKER_REBIND if rebinding failed
(CPU is down again).  This used to be okay because the flag wasn't
used for anything else.

However, after 25511a4 "workqueue: reimplement CPU online rebinding
to handle idle workers", WORKER_REBIND is also used to command idle
workers to rebind.  If not cleared, the worker may confuse the next
CPU_UP cycle by having REBIND spuriously set or oops / get stuck by
prematurely calling idle_worker_rebind().

  WARNING: at /work/os/wq/kernel/workqueue.c:1323 worker_thread+0x4cd/0x5
 00()
  Hardware name: Bochs
  Modules linked in: test_wq(O-)
  Pid: 33, comm: kworker/1:1 Tainted: G           O 3.6.0-rc1-work+ #3
  Call Trace:
   [<ffffffff8109039f>] warn_slowpath_common+0x7f/0xc0
   [<ffffffff810903fa>] warn_slowpath_null+0x1a/0x20
   [<ffffffff810b3f1d>] worker_thread+0x4cd/0x500
   [<ffffffff810bc16e>] kthread+0xbe/0xd0
   [<ffffffff81bd2664>] kernel_thread_helper+0x4/0x10
  ---[ end trace e977cf20f4661968 ]---
  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: [<ffffffff810b3db0>] worker_thread+0x360/0x500
  PGD 0
  Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
  Modules linked in: test_wq(O-)
  CPU 0
  Pid: 33, comm: kworker/1:1 Tainted: G        W  O 3.6.0-rc1-work+ #3 Bochs Bochs
  RIP: 0010:[<ffffffff810b3db0>]  [<ffffffff810b3db0>] worker_thread+0x360/0x500
  RSP: 0018:ffff88001e1c9de0  EFLAGS: 00010086
  RAX: 0000000000000000 RBX: ffff88001e633e00 RCX: 0000000000004140
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009
  RBP: ffff88001e1c9ea0 R08: 0000000000000000 R09: 0000000000000001
  R10: 0000000000000002 R11: 0000000000000000 R12: ffff88001fc8d580
  R13: ffff88001fc8d590 R14: ffff88001e633e20 R15: ffff88001e1c6900
  FS:  0000000000000000(0000) GS:ffff88001fc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 0000000000000000 CR3: 00000000130e8000 CR4: 00000000000006f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process kworker/1:1 (pid: 33, threadinfo ffff88001e1c8000, task ffff88001e1c6900)
  Stack:
   ffff880000000000 ffff88001e1c9e40 0000000000000001 ffff88001e1c8010
   ffff88001e519c78 ffff88001e1c9e58 ffff88001e1c6900 ffff88001e1c6900
   ffff88001e1c6900 ffff88001e1c6900 ffff88001fc8d340 ffff88001fc8d340
  Call Trace:
   [<ffffffff810bc16e>] kthread+0xbe/0xd0
   [<ffffffff81bd2664>] kernel_thread_helper+0x4/0x10
  Code: b1 00 f6 43 48 02 0f 85 91 01 00 00 48 8b 43 38 48 89 df 48 8b 00 48 89 45 90 e8 ac f0 ff ff 3c 01 0f 85 60 01 00 00 48 8b 53 50 <8b> 02 83 e8 01 85 c0 89 02 0f 84 3b 01 00 00 48 8b 43 38 48 8b
  RIP  [<ffffffff810b3db0>] worker_thread+0x360/0x500
   RSP <ffff88001e1c9de0>
  CR2: 0000000000000000

There was no reason to keep WORKER_REBIND on failure in the first
place - WORKER_UNBOUND is guaranteed to be set in such cases
preventing incorrectly activating concurrency management.  Always
clear WORKER_REBIND.

tj: Updated comment and description.

Signed-off-by: Lai Jiangshan <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
mitake pushed a commit that referenced this issue Oct 8, 2012
Cancel work of the xfs_sync_worker before teardown of the log in
xfs_unmountfs.  This prevents occasional crashes on unmount like so:

PID: 21602  TASK: ee9df060  CPU: 0   COMMAND: "kworker/0:3"
 #0 [c5377d28] crash_kexec at c0292c94
 #1 [c5377d80] oops_end at c07090c2
 #2 [c5377d98] no_context at c06f614e
 #3 [c5377dbc] __bad_area_nosemaphore at c06f6281
 #4 [c5377df4] bad_area_nosemaphore at c06f629b
 #5 [c5377e00] do_page_fault at c070b0cb
 torvalds#6 [c5377e7c] error_code (via page_fault) at c070892c
    EAX: f300c6a8  EBX: f300c6a8  ECX: 000000c0  EDX: 000000c0  EBP: c5377ed0
    DS:  007b      ESI: 00000000  ES:  007b      EDI: 00000001  GS:  ffffad20
    CS:  0060      EIP: c0481ad0  ERR: ffffffff  EFLAGS: 00010246
 torvalds#7 [c5377eb0] atomic64_read_cx8 at c0481ad0
 torvalds#8 [c5377ebc] xlog_assign_tail_lsn_locked at f7cc7c6e [xfs]
 torvalds#9 [c5377ed4] xfs_trans_ail_delete_bulk at f7ccd520 [xfs]
torvalds#10 [c5377f0c] xfs_buf_iodone at f7ccb602 [xfs]
torvalds#11 [c5377f24] xfs_buf_do_callbacks at f7cca524 [xfs]
torvalds#12 [c5377f30] xfs_buf_iodone_callbacks at f7cca5da [xfs]
torvalds#13 [c5377f4c] xfs_buf_iodone_work at f7c718d0 [xfs]
torvalds#14 [c5377f58] process_one_work at c024ee4c
torvalds#15 [c5377f98] worker_thread at c024f43d
torvalds#16 [c5377fb] kthread at c025326b
torvalds#17 [c5377fe8] kernel_thread_helper at c070e834

PID: 26653  TASK: e79143b0  CPU: 3   COMMAND: "umount"
 #0 [cde0fda0] __schedule at c0706595
 #1 [cde0fe28] schedule at c0706b89
 #2 [cde0fe30] schedule_timeout at c0705600
 #3 [cde0fe94] __down_common at c0706098
 #4 [cde0fec8] __down at c0706122
 #5 [cde0fed0] down at c025936f
 torvalds#6 [cde0fee0] xfs_buf_lock at f7c7131d [xfs]
 torvalds#7 [cde0ff00] xfs_freesb at f7cc2236 [xfs]
 torvalds#8 [cde0ff10] xfs_fs_put_super at f7c80f21 [xfs]
 torvalds#9 [cde0ff1c] generic_shutdown_super at c0333d7a
torvalds#10 [cde0ff38] kill_block_super at c0333e0f
torvalds#11 [cde0ff48] deactivate_locked_super at c0334218
torvalds#12 [cde0ff58] deactivate_super at c033495d
torvalds#13 [cde0ff68] mntput_no_expire at c034bc13
torvalds#14 [cde0ff7c] sys_umount at c034cc69
torvalds#15 [cde0ffa0] sys_oldumount at c034ccd4
torvalds#16 [cde0ffb0] system_call at c0707e66

commit 11159a0 added this to xfs_log_unmount and needs to be cleaned up
at a later date.

Signed-off-by: Ben Myers <[email protected]>
Reviewed-by: Dave Chinner <[email protected]>
Reviewed-by: Mark Tinguely <[email protected]>
mitake pushed a commit that referenced this issue Oct 8, 2012
When call_crda() is called we kick off a witch hunt search
for the same regulatory domain on our internal regulatory
database and that work gets kicked off on a workqueue, this
is done while the cfg80211_mutex is held. If that workqueue
kicks off it will first lock reg_regdb_search_mutex and
later cfg80211_mutex but to ensure two CPUs will not contend
against cfg80211_mutex the right thing to do is to have the
reg_regdb_search() wait until the cfg80211_mutex is let go.

The lockdep report is pasted below.

cfg80211: Calling CRDA to update world regulatory domain

======================================================
[ INFO: possible circular locking dependency detected ]
3.3.8 #3 Tainted: G           O
-------------------------------------------------------
kworker/0:1/235 is trying to acquire lock:
 (cfg80211_mutex){+.+...}, at: [<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

but task is already holding lock:
 (reg_regdb_search_mutex){+.+...}, at: [<81646828>] set_regdom+0x710/0x808 [cfg80211]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (reg_regdb_search_mutex){+.+...}:
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<81645778>] is_world_regdom+0x9f8/0xc74 [cfg80211]

-> #1 (reg_mutex#2){+.+...}:
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<8164539c>] is_world_regdom+0x61c/0xc74 [cfg80211]

-> #0 (cfg80211_mutex){+.+...}:
       [<800a77b8>] __lock_acquire+0x10d4/0x17bc
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

other info that might help us debug this:

Chain exists of:
  cfg80211_mutex --> reg_mutex#2 --> reg_regdb_search_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(reg_regdb_search_mutex);
                               lock(reg_mutex#2);
                               lock(reg_regdb_search_mutex);
  lock(cfg80211_mutex);

 *** DEADLOCK ***

3 locks held by kworker/0:1/235:
 #0:  (events){.+.+..}, at: [<80089a00>] process_one_work+0x230/0x460
 #1:  (reg_regdb_work){+.+...}, at: [<80089a00>] process_one_work+0x230/0x460
 #2:  (reg_regdb_search_mutex){+.+...}, at: [<81646828>] set_regdom+0x710/0x808 [cfg80211]

stack backtrace:
Call Trace:
[<80290fd4>] dump_stack+0x8/0x34
[<80291bc4>] print_circular_bug+0x2ac/0x2d8
[<800a77b8>] __lock_acquire+0x10d4/0x17bc
[<800a8384>] lock_acquire+0x60/0x88
[<802950a8>] mutex_lock_nested+0x54/0x31c
[<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

Reported-by: Felix Fietkau <[email protected]>
Tested-by: Felix Fietkau <[email protected]>
Cc: [email protected]
Signed-off-by: Luis R. Rodriguez <[email protected]>
Reviewed-by: Johannes Berg <[email protected]>
Signed-off-by: John W. Linville <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
Change since v1:

* Fixed inuse counters access spotted by Eric

In patch eea68e2 (packet: Report socket mclist info via diag module) I've
introduced a "scheduling in atomic" problem in packet diag module -- the
socket list is traversed under rcu_read_lock() while performed under it sk
mclist access requires rtnl lock (i.e. -- mutex) to be taken.

[152363.820563] BUG: scheduling while atomic: crtools/12517/0x10000002
[152363.820573] 4 locks held by crtools/12517:
[152363.820581]  #0:  (sock_diag_mutex){+.+.+.}, at: [<ffffffff81a2dcb5>] sock_diag_rcv+0x1f/0x3e
[152363.820613]  #1:  (sock_diag_table_mutex){+.+.+.}, at: [<ffffffff81a2de70>] sock_diag_rcv_msg+0xdb/0x11a
[152363.820644]  #2:  (nlk->cb_mutex){+.+.+.}, at: [<ffffffff81a67d01>] netlink_dump+0x23/0x1ab
[152363.820693]  #3:  (rcu_read_lock){.+.+..}, at: [<ffffffff81b6a049>] packet_diag_dump+0x0/0x1af

Similar thing was then re-introduced by further packet diag patches (fanount
mutex and pgvec mutex for rings) :(

Apart from being terribly sorry for the above, I propose to change the packet
sk list protection from spinlock to mutex. This lock currently protects two
modifications:

* sklist
* prot inuse counters

The sklist modifications can be just reprotected with mutex since they already
occur in a sleeping context. The inuse counters modifications are trickier -- the
__this_cpu_-s are used inside, thus requiring the caller to handle the potential
issues with contexts himself. Since packet sockets' counters are modified in two
places only (packet_create and packet_release) we only need to protect the context
from being preempted. BH disabling is not required in this case.

Signed-off-by: Pavel Emelyanov <[email protected]>
Acked-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
This moves ARM over to the asm-generic/unaligned.h header. This has the
benefit of better code generated especially for ARMv7 on gcc 4.7+
compilers.

As Arnd Bergmann, points out: The asm-generic version uses the "struct"
version for native-endian unaligned access and the "byteshift" version
for the opposite endianess. The current ARM version however uses the
"byteshift" implementation for both.

Thanks to Nicolas Pitre for the excellent analysis:

Test case:

int foo (int *x) { return get_unaligned(x); }
long long bar (long long *x) { return get_unaligned(x); }

With the current ARM version:

foo:
	ldrb	r3, [r0, #2]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 2B], MEM[(const u8 *)x_1(D) + 2B]
	ldrb	r1, [r0, #1]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 1B], MEM[(const u8 *)x_1(D) + 1B]
	ldrb	r2, [r0, #0]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D)], MEM[(const u8 *)x_1(D)]
	mov	r3, r3, asl torvalds#16	@ tmp154, MEM[(const u8 *)x_1(D) + 2B],
	ldrb	r0, [r0, #3]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 3B], MEM[(const u8 *)x_1(D) + 3B]
	orr	r3, r3, r1, asl torvalds#8	@, tmp155, tmp154, MEM[(const u8 *)x_1(D) + 1B],
	orr	r3, r3, r2	@ tmp157, tmp155, MEM[(const u8 *)x_1(D)]
	orr	r0, r3, r0, asl torvalds#24	@,, tmp157, MEM[(const u8 *)x_1(D) + 3B],
	bx	lr	@

bar:
	stmfd	sp!, {r4, r5, r6, r7}	@,
	mov	r2, #0	@ tmp184,
	ldrb	r5, [r0, torvalds#6]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 6B], MEM[(const u8 *)x_1(D) + 6B]
	ldrb	r4, [r0, #5]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 5B], MEM[(const u8 *)x_1(D) + 5B]
	ldrb	ip, [r0, #2]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 2B], MEM[(const u8 *)x_1(D) + 2B]
	ldrb	r1, [r0, #4]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 4B], MEM[(const u8 *)x_1(D) + 4B]
	mov	r5, r5, asl torvalds#16	@ tmp175, MEM[(const u8 *)x_1(D) + 6B],
	ldrb	r7, [r0, #1]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 1B], MEM[(const u8 *)x_1(D) + 1B]
	orr	r5, r5, r4, asl torvalds#8	@, tmp176, tmp175, MEM[(const u8 *)x_1(D) + 5B],
	ldrb	r6, [r0, torvalds#7]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 7B], MEM[(const u8 *)x_1(D) + 7B]
	orr	r5, r5, r1	@ tmp178, tmp176, MEM[(const u8 *)x_1(D) + 4B]
	ldrb	r4, [r0, #0]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D)], MEM[(const u8 *)x_1(D)]
	mov	ip, ip, asl torvalds#16	@ tmp188, MEM[(const u8 *)x_1(D) + 2B],
	ldrb	r1, [r0, #3]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 3B], MEM[(const u8 *)x_1(D) + 3B]
	orr	ip, ip, r7, asl torvalds#8	@, tmp189, tmp188, MEM[(const u8 *)x_1(D) + 1B],
	orr	r3, r5, r6, asl torvalds#24	@,, tmp178, MEM[(const u8 *)x_1(D) + 7B],
	orr	ip, ip, r4	@ tmp191, tmp189, MEM[(const u8 *)x_1(D)]
	orr	ip, ip, r1, asl torvalds#24	@, tmp194, tmp191, MEM[(const u8 *)x_1(D) + 3B],
	mov	r1, r3	@,
	orr	r0, r2, ip	@ tmp171, tmp184, tmp194
	ldmfd	sp!, {r4, r5, r6, r7}
	bx	lr

In both cases the code is slightly suboptimal.  One may wonder why
wasting r2 with the constant 0 in the second case for example.  And all
the mov's could be folded in subsequent orr's, etc.

Now with the asm-generic version:

foo:
	ldr	r0, [r0, #0]	@ unaligned	@,* x
	bx	lr	@

bar:
	mov	r3, r0	@ x, x
	ldr	r0, [r0, #0]	@ unaligned	@,* x
	ldr	r1, [r3, #4]	@ unaligned	@,
	bx	lr	@

This is way better of course, but only because this was compiled for
ARMv7. In this case the compiler knows that the hardware can do
unaligned word access.  This isn't that obvious for foo(), but if we
remove the get_unaligned() from bar as follows:

long long bar (long long *x) {return *x; }

then the resulting code is:

bar:
	ldmia	r0, {r0, r1}	@ x,,
	bx	lr	@

So this proves that the presumed aligned vs unaligned cases does have
influence on the instructions the compiler may use and that the above
unaligned code results are not just an accident.

Still... this isn't fully conclusive without at least looking at the
resulting assembly fron a pre ARMv6 compilation.  Let's see with an
ARMv5 target:

foo:
	ldrb	r3, [r0, #0]	@ zero_extendqisi2	@ tmp139,* x
	ldrb	r1, [r0, #1]	@ zero_extendqisi2	@ tmp140,
	ldrb	r2, [r0, #2]	@ zero_extendqisi2	@ tmp143,
	ldrb	r0, [r0, #3]	@ zero_extendqisi2	@ tmp146,
	orr	r3, r3, r1, asl torvalds#8	@, tmp142, tmp139, tmp140,
	orr	r3, r3, r2, asl torvalds#16	@, tmp145, tmp142, tmp143,
	orr	r0, r3, r0, asl torvalds#24	@,, tmp145, tmp146,
	bx	lr	@

bar:
	stmfd	sp!, {r4, r5, r6, r7}	@,
	ldrb	r2, [r0, #0]	@ zero_extendqisi2	@ tmp139,* x
	ldrb	r7, [r0, #1]	@ zero_extendqisi2	@ tmp140,
	ldrb	r3, [r0, #4]	@ zero_extendqisi2	@ tmp149,
	ldrb	r6, [r0, #5]	@ zero_extendqisi2	@ tmp150,
	ldrb	r5, [r0, #2]	@ zero_extendqisi2	@ tmp143,
	ldrb	r4, [r0, torvalds#6]	@ zero_extendqisi2	@ tmp153,
	ldrb	r1, [r0, torvalds#7]	@ zero_extendqisi2	@ tmp156,
	ldrb	ip, [r0, #3]	@ zero_extendqisi2	@ tmp146,
	orr	r2, r2, r7, asl torvalds#8	@, tmp142, tmp139, tmp140,
	orr	r3, r3, r6, asl torvalds#8	@, tmp152, tmp149, tmp150,
	orr	r2, r2, r5, asl torvalds#16	@, tmp145, tmp142, tmp143,
	orr	r3, r3, r4, asl torvalds#16	@, tmp155, tmp152, tmp153,
	orr	r0, r2, ip, asl torvalds#24	@,, tmp145, tmp146,
	orr	r1, r3, r1, asl torvalds#24	@,, tmp155, tmp156,
	ldmfd	sp!, {r4, r5, r6, r7}
	bx	lr

Compared to the initial results, this is really nicely optimized and I
couldn't do much better if I were to hand code it myself.

Signed-off-by: Rob Herring <[email protected]>
Reviewed-by: Nicolas Pitre <[email protected]>
Tested-by: Thomas Petazzoni <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Russell King <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
It seems we need to provide ability for stacked devices
to use specific lock_class_key for sch->busylock

We could instead default l2tpeth tx_queue_len to 0 (no qdisc), but
a user might use a qdisc anyway.

(So same fixes are probably needed on non LLTX stacked drivers)

Noticed while stressing L2TPV3 setup :

======================================================
 [ INFO: possible circular locking dependency detected ]
 3.6.0-rc3+ #788 Not tainted
 -------------------------------------------------------
 netperf/4660 is trying to acquire lock:
  (l2tpsock){+.-...}, at: [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]

 but task is already holding lock:
  (&(&sch->busylock)->rlock){+.-...}, at: [<ffffffff81596595>] dev_queue_xmit+0xd75/0xe00

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&(&sch->busylock)->rlock){+.-...}:
        [<ffffffff810a5df0>] lock_acquire+0x90/0x200
        [<ffffffff817499fc>] _raw_spin_lock_irqsave+0x4c/0x60
        [<ffffffff81074872>] __wake_up+0x32/0x70
        [<ffffffff8136d39e>] tty_wakeup+0x3e/0x80
        [<ffffffff81378fb3>] pty_write+0x73/0x80
        [<ffffffff8136cb4c>] tty_put_char+0x3c/0x40
        [<ffffffff813722b2>] process_echoes+0x142/0x330
        [<ffffffff813742ab>] n_tty_receive_buf+0x8fb/0x1230
        [<ffffffff813777b2>] flush_to_ldisc+0x142/0x1c0
        [<ffffffff81062818>] process_one_work+0x198/0x760
        [<ffffffff81063236>] worker_thread+0x186/0x4b0
        [<ffffffff810694d3>] kthread+0x93/0xa0
        [<ffffffff81753e24>] kernel_thread_helper+0x4/0x10

 -> #0 (l2tpsock){+.-...}:
        [<ffffffff810a5288>] __lock_acquire+0x1628/0x1b10
        [<ffffffff810a5df0>] lock_acquire+0x90/0x200
        [<ffffffff817498c1>] _raw_spin_lock+0x41/0x50
        [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
        [<ffffffffa021a802>] l2tp_eth_dev_xmit+0x32/0x60 [l2tp_eth]
        [<ffffffff815952b2>] dev_hard_start_xmit+0x502/0xa70
        [<ffffffff815b63ce>] sch_direct_xmit+0xfe/0x290
        [<ffffffff81595a05>] dev_queue_xmit+0x1e5/0xe00
        [<ffffffff815d9d60>] ip_finish_output+0x3d0/0x890
        [<ffffffff815db019>] ip_output+0x59/0xf0
        [<ffffffff815da36d>] ip_local_out+0x2d/0xa0
        [<ffffffff815da5a3>] ip_queue_xmit+0x1c3/0x680
        [<ffffffff815f4192>] tcp_transmit_skb+0x402/0xa60
        [<ffffffff815f4a94>] tcp_write_xmit+0x1f4/0xa30
        [<ffffffff815f5300>] tcp_push_one+0x30/0x40
        [<ffffffff815e6672>] tcp_sendmsg+0xe82/0x1040
        [<ffffffff81614495>] inet_sendmsg+0x125/0x230
        [<ffffffff81576cdc>] sock_sendmsg+0xdc/0xf0
        [<ffffffff81579ece>] sys_sendto+0xfe/0x130
        [<ffffffff81752c92>] system_call_fastpath+0x16/0x1b
  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&(&sch->busylock)->rlock);
                                lock(l2tpsock);
                                lock(&(&sch->busylock)->rlock);
   lock(l2tpsock);

  *** DEADLOCK ***

 5 locks held by netperf/4660:
  #0:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff815e581c>] tcp_sendmsg+0x2c/0x1040
  #1:  (rcu_read_lock){.+.+..}, at: [<ffffffff815da3e0>] ip_queue_xmit+0x0/0x680
  #2:  (rcu_read_lock_bh){.+....}, at: [<ffffffff815d9ac5>] ip_finish_output+0x135/0x890
  #3:  (rcu_read_lock_bh){.+....}, at: [<ffffffff81595820>] dev_queue_xmit+0x0/0xe00
  #4:  (&(&sch->busylock)->rlock){+.-...}, at: [<ffffffff81596595>] dev_queue_xmit+0xd75/0xe00

 stack backtrace:
 Pid: 4660, comm: netperf Not tainted 3.6.0-rc3+ #788
 Call Trace:
  [<ffffffff8173dbf8>] print_circular_bug+0x1fb/0x20c
  [<ffffffff810a5288>] __lock_acquire+0x1628/0x1b10
  [<ffffffff810a334b>] ? check_usage+0x9b/0x4d0
  [<ffffffff810a3f44>] ? __lock_acquire+0x2e4/0x1b10
  [<ffffffff810a5df0>] lock_acquire+0x90/0x200
  [<ffffffffa0208db2>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
  [<ffffffff817498c1>] _raw_spin_lock+0x41/0x50
  [<ffffffffa0208db2>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
  [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
  [<ffffffffa021a802>] l2tp_eth_dev_xmit+0x32/0x60 [l2tp_eth]
  [<ffffffff815952b2>] dev_hard_start_xmit+0x502/0xa70
  [<ffffffff81594e0e>] ? dev_hard_start_xmit+0x5e/0xa70
  [<ffffffff81595961>] ? dev_queue_xmit+0x141/0xe00
  [<ffffffff815b63ce>] sch_direct_xmit+0xfe/0x290
  [<ffffffff81595a05>] dev_queue_xmit+0x1e5/0xe00
  [<ffffffff81595820>] ? dev_hard_start_xmit+0xa70/0xa70
  [<ffffffff815d9d60>] ip_finish_output+0x3d0/0x890
  [<ffffffff815d9ac5>] ? ip_finish_output+0x135/0x890
  [<ffffffff815db019>] ip_output+0x59/0xf0
  [<ffffffff815da36d>] ip_local_out+0x2d/0xa0
  [<ffffffff815da5a3>] ip_queue_xmit+0x1c3/0x680
  [<ffffffff815da3e0>] ? ip_local_out+0xa0/0xa0
  [<ffffffff815f4192>] tcp_transmit_skb+0x402/0xa60
  [<ffffffff815fa25e>] ? tcp_md5_do_lookup+0x18e/0x1a0
  [<ffffffff815f4a94>] tcp_write_xmit+0x1f4/0xa30
  [<ffffffff815f5300>] tcp_push_one+0x30/0x40
  [<ffffffff815e6672>] tcp_sendmsg+0xe82/0x1040
  [<ffffffff81614495>] inet_sendmsg+0x125/0x230
  [<ffffffff81614370>] ? inet_create+0x6b0/0x6b0
  [<ffffffff8157e6e2>] ? sock_update_classid+0xc2/0x3b0
  [<ffffffff8157e750>] ? sock_update_classid+0x130/0x3b0
  [<ffffffff81576cdc>] sock_sendmsg+0xdc/0xf0
  [<ffffffff81162579>] ? fget_light+0x3f9/0x4f0
  [<ffffffff81579ece>] sys_sendto+0xfe/0x130
  [<ffffffff810a69ad>] ? trace_hardirqs_on+0xd/0x10
  [<ffffffff8174a0b0>] ? _raw_spin_unlock_irq+0x30/0x50
  [<ffffffff810757e3>] ? finish_task_switch+0x83/0xf0
  [<ffffffff810757a6>] ? finish_task_switch+0x46/0xf0
  [<ffffffff81752cb7>] ? sysret_check+0x1b/0x56
  [<ffffffff81752c92>] system_call_fastpath+0x16/0x1b

Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
Cancel work of the xfs_sync_worker before teardown of the log in
xfs_unmountfs.  This prevents occasional crashes on unmount like so:

PID: 21602  TASK: ee9df060  CPU: 0   COMMAND: "kworker/0:3"
 #0 [c5377d28] crash_kexec at c0292c94
 #1 [c5377d80] oops_end at c07090c2
 #2 [c5377d98] no_context at c06f614e
 #3 [c5377dbc] __bad_area_nosemaphore at c06f6281
 #4 [c5377df4] bad_area_nosemaphore at c06f629b
 #5 [c5377e00] do_page_fault at c070b0cb
 torvalds#6 [c5377e7c] error_code (via page_fault) at c070892c
    EAX: f300c6a8  EBX: f300c6a8  ECX: 000000c0  EDX: 000000c0  EBP: c5377ed0
    DS:  007b      ESI: 00000000  ES:  007b      EDI: 00000001  GS:  ffffad20
    CS:  0060      EIP: c0481ad0  ERR: ffffffff  EFLAGS: 00010246
 torvalds#7 [c5377eb0] atomic64_read_cx8 at c0481ad0
 torvalds#8 [c5377ebc] xlog_assign_tail_lsn_locked at f7cc7c6e [xfs]
 torvalds#9 [c5377ed4] xfs_trans_ail_delete_bulk at f7ccd520 [xfs]
torvalds#10 [c5377f0c] xfs_buf_iodone at f7ccb602 [xfs]
torvalds#11 [c5377f24] xfs_buf_do_callbacks at f7cca524 [xfs]
torvalds#12 [c5377f30] xfs_buf_iodone_callbacks at f7cca5da [xfs]
torvalds#13 [c5377f4c] xfs_buf_iodone_work at f7c718d0 [xfs]
torvalds#14 [c5377f58] process_one_work at c024ee4c
torvalds#15 [c5377f98] worker_thread at c024f43d
torvalds#16 [c5377fb] kthread at c025326b
torvalds#17 [c5377fe8] kernel_thread_helper at c070e834

PID: 26653  TASK: e79143b0  CPU: 3   COMMAND: "umount"
 #0 [cde0fda0] __schedule at c0706595
 #1 [cde0fe28] schedule at c0706b89
 #2 [cde0fe30] schedule_timeout at c0705600
 #3 [cde0fe94] __down_common at c0706098
 #4 [cde0fec8] __down at c0706122
 #5 [cde0fed0] down at c025936f
 torvalds#6 [cde0fee0] xfs_buf_lock at f7c7131d [xfs]
 torvalds#7 [cde0ff00] xfs_freesb at f7cc2236 [xfs]
 torvalds#8 [cde0ff10] xfs_fs_put_super at f7c80f21 [xfs]
 torvalds#9 [cde0ff1c] generic_shutdown_super at c0333d7a
torvalds#10 [cde0ff38] kill_block_super at c0333e0f
torvalds#11 [cde0ff48] deactivate_locked_super at c0334218
torvalds#12 [cde0ff58] deactivate_super at c033495d
torvalds#13 [cde0ff68] mntput_no_expire at c034bc13
torvalds#14 [cde0ff7c] sys_umount at c034cc69
torvalds#15 [cde0ffa0] sys_oldumount at c034ccd4
torvalds#16 [cde0ffb0] system_call at c0707e66

commit 11159a0 added this to xfs_log_unmount and needs to be cleaned up
at a later date.

Signed-off-by: Ben Myers <[email protected]>
Reviewed-by: Dave Chinner <[email protected]>
Reviewed-by: Mark Tinguely <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
Commit a9277e7
"[SCSI] scsi_transport_fc: Getting FC Port Speed in sync with FC-GS"
changed the semantics of FC_PORTSPEED defines to
FDMI port attributes of FC-HBA/SM-HBA
which is different from the previous bit reversed
Report Port Speed Capabilities (RPSC) ELS of FC-GS/FC-LS.

Zfcp showed "10 Gbit" instead of "4 Gbit" for supported_speeds.
It now uses explicit bit conversion as the other LLDs already
do, in order to be independent of the kernel bit semantics.
See also http://marc.info/?l=linux-scsi&m=134452926830730&w=2

Signed-off-by: Steffen Maier <[email protected]>
Reviewed-by: Martin Peschke <[email protected]>
Cc: <[email protected]> #3.4+
Signed-off-by: James Bottomley <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
The pl vector has scount elements, i.e. pl[scount-1] is the last valid
element. For maximum sized requests, payload->counter == scount after
the last loop iteration. Therefore, do bounds checking first (with
boolean shortcut) to not access the invalid element pl[scount].

Do not trust the maximum sbale->scount value from the HBA
but ensure we won't access the pl vector out of our allocated bounds.
While at it, clean up scoping and prevent unnecessary memset.

Minor fix for 86a9668
"[SCSI] zfcp: support for hardware data router"

Signed-off-by: Steffen Maier <[email protected]>
Reviewed-by: Martin Peschke <[email protected]>
Cc: <[email protected]> #3.2+
Signed-off-by: James Bottomley <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
Do not kfree() the mtd_info; it is handled in the mtd subsystem and
already freed by nand_release(). Instead kfree() the struct
omap_nand_info allocated in omap_nand_probe which was not freed before.

This patch fixes following error when unloading the omap2 module:

---8<---
~ $ rmmod omap2
------------[ cut here ]------------
kernel BUG at mm/slab.c:3126!
Internal error: Oops - BUG: 0 [#1] PREEMPT ARM
Modules linked in: omap2(-)
CPU: 0    Not tainted  (3.6.0-rc3-00230-g155e36d-dirty #3)
PC is at cache_free_debugcheck+0x2d4/0x36c
LR is at kfree+0xc8/0x2ac
pc : [<c01125a0>]    lr : [<c0112efc>]    psr: 200d0193
sp : c521fe08  ip : c0e8ef90  fp : c521fe5c
r10: bf0001fc  r9 : c521e000  r8 : c0d99c8c
r7 : c661ebc0  r6 : c065d5a4  r5 : c65c4060  r4 : c78005c0
r3 : 00000000  r2 : 00001000  r1 : c65c4000  r0 : 00000001
Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 10c5387d  Table: 86694019  DAC: 00000015
Process rmmod (pid: 549, stack limit = 0xc521e2f0)
Stack: (0xc521fe08 to 0xc5220000)
fe00:                   c008a874 c00bf44c c515c6d0 200d0193 c65c4860 c515c240
fe20: c521fe3c c521fe30 c008a9c0 c008a854 c521fe5c c65c4860 c78005c0 bf0001fc
fe40: c780ff40 a00d0113 c521e000 00000000 c521fe84 c521fe60 c0112efc c01122d8
fe60: c65c4860 c0673778 c06737ac 00000000 00070013 00000000 c521fe9c c521fe88
fe80: bf0001fc c0112e40 c0673778 bf001ca8 c521feac c521fea0 c02ca11c bf0001ac
fea0: c521fec4 c521feb0 c02c82c4 c02ca100 c0673778 bf001ca8 c521fee4 c521fec8
fec0: c02c8dd8 c02c8250 00000000 bf001ca8 bf001ca8 c0804ee0 c521ff04 c521fee8
fee0: c02c804c c02c8d20 bf001924 00000000 bf001ca8 c521e000 c521ff1c c521ff08
ff00: c02c950c c02c7fbc bf001d48 00000000 c521ff2c c521ff20 c02ca3a4 c02c94b8
ff20: c521ff3c c521ff30 bf001938 c02ca394 c521ffa4 c521ff40 c009beb4 bf001930
ff40: c521ff6c 70616d6f b6fe0032 c0014f84 70616d6f b6fe0032 00000081 60070010
ff60: c521ff84 c521ff70 c008e1f4 c00bf328 0001a004 70616d6f c521ff94 0021ff88
ff80: c008e368 0001a004 70616d6f b6fe0032 00000081 c0015028 00000000 c521ffa8
ffa0: c0014dc0 c009bcd0 0001a004 70616d6f bec2ab38 00000880 bec2ab38 00000880
ffc0: 0001a004 70616d6f b6fe0032 00000081 00000319 00000000 b6fe1000 00000000
ffe0: bec2ab30 bec2ab20 00019f00 b6f539c0 60070010 bec2ab38 aaaaaaaa aaaaaaaa
Backtrace:
[<c01122cc>] (cache_free_debugcheck+0x0/0x36c) from [<c0112efc>] (kfree+0xc8/0x2ac)
[<c0112e34>] (kfree+0x0/0x2ac) from [<bf0001fc>] (omap_nand_remove+0x5c/0x64 [omap2])
[<bf0001a0>] (omap_nand_remove+0x0/0x64 [omap2]) from [<c02ca11c>] (platform_drv_remove+0x28/0x2c)
 r5:bf001ca8 r4:c0673778
[<c02ca0f4>] (platform_drv_remove+0x0/0x2c) from [<c02c82c4>] (__device_release_driver+0x80/0xdc)
[<c02c8244>] (__device_release_driver+0x0/0xdc) from [<c02c8dd8>] (driver_detach+0xc4/0xc8)
 r5:bf001ca8 r4:c0673778
[<c02c8d14>] (driver_detach+0x0/0xc8) from [<c02c804c>] (bus_remove_driver+0x9c/0x104)
 r6:c0804ee0 r5:bf001ca8 r4:bf001ca8 r3:00000000
[<c02c7fb0>] (bus_remove_driver+0x0/0x104) from [<c02c950c>] (driver_unregister+0x60/0x80)
 r6:c521e000 r5:bf001ca8 r4:00000000 r3:bf001924
[<c02c94ac>] (driver_unregister+0x0/0x80) from [<c02ca3a4>] (platform_driver_unregister+0x1c/0x20)
 r5:00000000 r4:bf001d48
[<c02ca388>] (platform_driver_unregister+0x0/0x20) from [<bf001938>] (omap_nand_driver_exit+0x14/0x1c [omap2])
[<bf001924>] (omap_nand_driver_exit+0x0/0x1c [omap2]) from [<c009beb4>] (sys_delete_module+0x1f0/0x2ec)
[<c009bcc4>] (sys_delete_module+0x0/0x2ec) from [<c0014dc0>] (ret_fast_syscall+0x0/0x48)
 r8:c0015028 r7:00000081 r6:b6fe0032 r5:70616d6f r4:0001a004
Code: e1a00005 eb0d9172 e7f001f2 e7f001f2 (e7f001f2)
---[ end trace 6a30b24d8c0cc2ee ]---
Segmentation fault
--->8---

This error was introduced in 67ce04b which
was the first commit of this driver.

Signed-off-by: Andreas Bießmann <[email protected]>
Cc: [email protected]
Signed-off-by: Artem Bityutskiy <[email protected]>
Signed-off-by: David Woodhouse <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
If a qdisc is installed on a bonding device, its possible to get
following lockdep splat under stress :

 =============================================
 [ INFO: possible recursive locking detected ]
 3.6.0+ torvalds#211 Not tainted
 ---------------------------------------------
 ping/4876 is trying to acquire lock:
  (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-...}, at: [<ffffffff8157a191>] dev_queue_xmit+0xe1/0x830

 but task is already holding lock:
  (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-...}, at: [<ffffffff8157a191>] dev_queue_xmit+0xe1/0x830

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

        CPU0
        ----
   lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock);
   lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 6 locks held by ping/4876:
  #0:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff815e5030>] raw_sendmsg+0x600/0xc30
  #1:  (rcu_read_lock_bh){.+....}, at: [<ffffffff815ba4bd>] ip_finish_output+0x12d/0x870
  #2:  (rcu_read_lock_bh){.+....}, at: [<ffffffff8157a0b0>] dev_queue_xmit+0x0/0x830
  #3:  (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-...}, at: [<ffffffff8157a191>] dev_queue_xmit+0xe1/0x830
  #4:  (&bond->lock){++.?..}, at: [<ffffffffa02128c1>] bond_start_xmit+0x31/0x4b0 [bonding]
  #5:  (rcu_read_lock_bh){.+....}, at: [<ffffffff8157a0b0>] dev_queue_xmit+0x0/0x830

 stack backtrace:
 Pid: 4876, comm: ping Not tainted 3.6.0+ torvalds#211
 Call Trace:
  [<ffffffff810a0145>] __lock_acquire+0x715/0x1b80
  [<ffffffff810a256b>] ? mark_held_locks+0x9b/0x100
  [<ffffffff810a1bf2>] lock_acquire+0x92/0x1d0
  [<ffffffff8157a191>] ? dev_queue_xmit+0xe1/0x830
  [<ffffffff81726b7c>] _raw_spin_lock+0x3c/0x50
  [<ffffffff8157a191>] ? dev_queue_xmit+0xe1/0x830
  [<ffffffff8106264d>] ? rcu_read_lock_bh_held+0x5d/0x90
  [<ffffffff8157a191>] dev_queue_xmit+0xe1/0x830
  [<ffffffff8157a0b0>] ? netdev_pick_tx+0x570/0x570
  [<ffffffffa0212a6a>] bond_start_xmit+0x1da/0x4b0 [bonding]
  [<ffffffff815796d0>] dev_hard_start_xmit+0x240/0x6b0
  [<ffffffff81597c6e>] sch_direct_xmit+0xfe/0x2a0
  [<ffffffff8157a249>] dev_queue_xmit+0x199/0x830
  [<ffffffff8157a0b0>] ? netdev_pick_tx+0x570/0x570
  [<ffffffff815ba96f>] ip_finish_output+0x5df/0x870
  [<ffffffff815ba4bd>] ? ip_finish_output+0x12d/0x870
  [<ffffffff815bb964>] ip_output+0x54/0xf0
  [<ffffffff815bad48>] ip_local_out+0x28/0x90
  [<ffffffff815bc444>] ip_send_skb+0x14/0x50
  [<ffffffff815bc4b2>] ip_push_pending_frames+0x32/0x40
  [<ffffffff815e536a>] raw_sendmsg+0x93a/0xc30
  [<ffffffff8128d570>] ? selinux_file_send_sigiotask+0x1f0/0x1f0
  [<ffffffff8109ddb4>] ? __lock_is_held+0x54/0x80
  [<ffffffff815f6730>] ? inet_recvmsg+0x220/0x220
  [<ffffffff8109ddb4>] ? __lock_is_held+0x54/0x80
  [<ffffffff815f6855>] inet_sendmsg+0x125/0x240
  [<ffffffff815f6730>] ? inet_recvmsg+0x220/0x220
  [<ffffffff8155cddb>] sock_sendmsg+0xab/0xe0
  [<ffffffff810a1650>] ? lock_release_non_nested+0xa0/0x2e0
  [<ffffffff810a1650>] ? lock_release_non_nested+0xa0/0x2e0
  [<ffffffff8155d18c>] __sys_sendmsg+0x37c/0x390
  [<ffffffff81195b2a>] ? fsnotify+0x2ca/0x7e0
  [<ffffffff811958e8>] ? fsnotify+0x88/0x7e0
  [<ffffffff81361f36>] ? put_ldisc+0x56/0xd0
  [<ffffffff8116f98a>] ? fget_light+0x3da/0x510
  [<ffffffff8155f6c4>] sys_sendmsg+0x44/0x80
  [<ffffffff8172fc22>] system_call_fastpath+0x16/0x1b

Avoid this problem using a distinct lock_class_key for bonding
devices.

Signed-off-by: Eric Dumazet <[email protected]>
Cc: Jay Vosburgh <[email protected]>
Cc: Andy Gospodarek <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
On a KVM guest, when a CPU is taken offline and brought back online, we hit
the following NULL pointer dereference:

[   45.400843] Unregister pv shared memory for cpu 1
[   45.412331] smpboot: CPU 1 is now offline
[   45.529894] SMP alternatives: lockdep: fixing up alternatives
[   45.533472] smpboot: Booting Node 0 Processor 1 APIC 0x1
[   45.411526] kvm-clock: cpu 1, msr 0:7d14601, secondary cpu clock
[   45.571370] KVM setup async PF for cpu 1
[   45.572331] kvm-stealtime: cpu 1, msr 7d0e040
[   45.575031] BUG: unable to handle kernel NULL pointer dereference at           (null)
[   45.576017] IP: [<ffffffff81519f98>] cpuidle_disable_device+0x18/0x80
[   45.576017] PGD 5dfb067 PUD 5da8067 PMD 0
[   45.576017] Oops: 0000 [#1] SMP
[   45.576017] Modules linked in:
[   45.576017] CPU 0
[   45.576017] Pid: 607, comm: stress_cpu_hotp Not tainted 3.6.0-padata-tp-debug #3 Bochs Bochs
[   45.576017] RIP: 0010:[<ffffffff81519f98>]  [<ffffffff81519f98>] cpuidle_disable_device+0x18/0x80
[   45.576017] RSP: 0018:ffff880005d93ce8  EFLAGS: 00010286
[   45.576017] RAX: ffff880005d93fd8 RBX: 0000000000000000 RCX: 0000000000000006
[   45.576017] RDX: 0000000000000006 RSI: 2222222222222222 RDI: 0000000000000000
[   45.576017] RBP: ffff880005d93cf8 R08: 2222222222222222 R09: 2222222222222222
[   45.576017] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   45.576017] R13: 0000000000000000 R14: ffffffff81c8cca0 R15: 0000000000000001
[   45.576017] FS:  00007f91936ae700(0000) GS:ffff880007c00000(0000) knlGS:0000000000000000
[   45.576017] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   45.576017] CR2: 0000000000000000 CR3: 0000000005db3000 CR4: 00000000000006f0
[   45.576017] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   45.576017] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   45.576017] Process stress_cpu_hotp (pid: 607, threadinfo ffff880005d92000, task ffff8800066bbf40)
[   45.576017] Stack:
[   45.576017]  ffff880007a96400 0000000000000000 ffff880005d93d28 ffffffff813ac689
[   45.576017]  ffff880007a96400 ffff880007a96400 0000000000000002 ffffffff81cd8d01
[   45.576017]  ffff880005d93d58 ffffffff813aa498 0000000000000001 00000000ffffffdd
[   45.576017] Call Trace:
[   45.576017]  [<ffffffff813ac689>] acpi_processor_hotplug+0x55/0x97
[   45.576017]  [<ffffffff813aa498>] acpi_cpu_soft_notify+0x93/0xce
[   45.576017]  [<ffffffff816ae47d>] notifier_call_chain+0x5d/0x110
[   45.576017]  [<ffffffff8109730e>] __raw_notifier_call_chain+0xe/0x10
[   45.576017]  [<ffffffff81069050>] __cpu_notify+0x20/0x40
[   45.576017]  [<ffffffff81069085>] cpu_notify+0x15/0x20
[   45.576017]  [<ffffffff816978f1>] _cpu_up+0xee/0x137
[   45.576017]  [<ffffffff81697983>] cpu_up+0x49/0x59
[   45.576017]  [<ffffffff8168758d>] store_online+0x9d/0xe0
[   45.576017]  [<ffffffff8140a9f8>] dev_attr_store+0x18/0x30
[   45.576017]  [<ffffffff812322c0>] sysfs_write_file+0xe0/0x150
[   45.576017]  [<ffffffff811b389c>] vfs_write+0xac/0x180
[   45.576017]  [<ffffffff811b3be2>] sys_write+0x52/0xa0
[   45.576017]  [<ffffffff816b31e9>] system_call_fastpath+0x16/0x1b
[   45.576017] Code: 48 c7 c7 40 e5 ca 81 e8 07 d0 18 00 5d c3 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 48 83 ec 10 48 89 5d f0 4c 89 65 f8 48 89 fb <f6> 07 02 75 13 48 8b 5d f0 4c 8b 65 f8 c9 c3 66 0f 1f 84 00 00
[   45.576017] RIP  [<ffffffff81519f98>] cpuidle_disable_device+0x18/0x80
[   45.576017]  RSP <ffff880005d93ce8>
[   45.576017] CR2: 0000000000000000
[   45.656079] ---[ end trace 433d6c9ac0b02cef ]---

Analysis:
Commit 3d339dc (cpuidle / ACPI : move cpuidle_device field out of the
acpi_processor_power structure()) made the allocation of the dev structure
(struct cpuidle) of a CPU dynamic, whereas previously it was statically
allocated. And this dynamic allocation occurs in acpi_processor_power_init()
if pr->flags.power evaluates to non-zero.

On KVM guests, pr->flags.power evaluates to zero, hence dev is never
allocated. This causes the NULL pointer (dev) dereference in
cpuidle_disable_device() during a subsequent CPU online operation. Fix this
by ensuring that dev is non-NULL before dereferencing.

Signed-off-by: Srivatsa S. Bhat <[email protected]>
Signed-off-by: Len Brown <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
tpm_write calls tpm_transmit without checking the return value and
assigns the return value unconditionally to chip->pending_data, even if
it's an error value.
This causes three bugs.

So if we write to /dev/tpm0 with a tpm_param_size bigger than
TPM_BUFSIZE=0x1000 (e.g. 0x100a)
and a bufsize also bigger than TPM_BUFSIZE (e.g. 0x100a)
tpm_transmit returns -E2BIG which is assigned to chip->pending_data as
-7, but tpm_write returns that TPM_BUFSIZE bytes have been successfully
been written to the TPM, altough this is not true (bug #1).

As we did write more than than TPM_BUFSIZE bytes but tpm_write reports
that only TPM_BUFSIZE bytes have been written the vfs tries to write
the remaining bytes (in this case 10 bytes) to the tpm device driver via
tpm_write which then blocks at

 /* cannot perform a write until the read has cleared
 either via tpm_read or a user_read_timer timeout */
 while (atomic_read(&chip->data_pending) != 0)
	 msleep(TPM_TIMEOUT);

for 60 seconds, since data_pending is -7 and nobody is able to
read it (since tpm_read luckily checks if data_pending is greater than
0) (#bug 2).

After that the remaining bytes are written to the TPM which are
interpreted by the tpm as a normal command. (bug #3)
So if the last bytes of the command stream happen to be a e.g.
tpm_force_clear this gets accidentally sent to the TPM.

This patch fixes all three bugs, by propagating the error code of
tpm_write and returning -E2BIG if the input buffer is too big,
since the response from the tpm for a truncated value is bogus anyway.
Moreover it returns -EBUSY to userspace if there is a response ready to be
read.

Signed-off-by: Peter Huewe <[email protected]>
Signed-off-by: Kent Yoder <[email protected]>
mitake pushed a commit that referenced this issue Nov 18, 2012
Calling __pa() with an ioremap'd address is invalid. If we
encounter an efi_memory_desc_t without EFI_MEMORY_WB set in
->attribute we currently call set_memory_uc(), which in turn
calls __pa() on a potentially ioremap'd address.

On CONFIG_X86_32 this results in the following oops:

  BUG: unable to handle kernel paging request at f7f22280
  IP: [<c10257b9>] reserve_ram_pages_type+0x89/0x210
  *pdpt = 0000000001978001 *pde = 0000000001ffb067 *pte = 0000000000000000
  Oops: 0000 [#1] PREEMPT SMP
  Modules linked in:

  Pid: 0, comm: swapper Not tainted 3.0.0-acpi-efi-0805 #3
   EIP: 0060:[<c10257b9>] EFLAGS: 00010202 CPU: 0
   EIP is at reserve_ram_pages_type+0x89/0x210
   EAX: 0070e280 EBX: 38714000 ECX: f7814000 EDX: 00000000
   ESI: 00000000 EDI: 38715000 EBP: c189fef0 ESP: c189fea8
   DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
  Process swapper (pid: 0, ti=c189e000 task=c18bbe60 task.ti=c189e000)
  Stack:
   80000200 ff108000 00000000 c189ff00 00038714 00000000 00000000 c189fed0
   c104f8ca 00038714 00000000 00038715 00000000 00000000 00038715 00000000
   00000010 38715000 c189ff48 c1025aff 38715000 00000000 00000010 00000000
  Call Trace:
   [<c104f8ca>] ? page_is_ram+0x1a/0x40
   [<c1025aff>] reserve_memtype+0xdf/0x2f0
   [<c1024dc9>] set_memory_uc+0x49/0xa0
   [<c19334d0>] efi_enter_virtual_mode+0x1c2/0x3aa
   [<c19216d4>] start_kernel+0x291/0x2f2
   [<c19211c7>] ? loglevel+0x1b/0x1b
   [<c19210bf>] i386_start_kernel+0xbf/0xc8

The only time we can call set_memory_uc() for a memory region is
when it is part of the direct kernel mapping. For the case where
we ioremap a memory region we must leave it alone.

This patch reimplements the fix from e8c7106 ("x86, efi:
Calling __pa() with an ioremap()ed address is invalid") which
was reverted in e1ad783 because it caused a regression on
some MacBooks (they hung at boot). The regression was caused
because the commit only marked EFI_RUNTIME_SERVICES_DATA as
E820_RESERVED_EFI, when it should have marked all regions that
have the EFI_MEMORY_RUNTIME attribute.

Despite first impressions, it's not possible to use
ioremap_cache() to map all cached memory regions on
CONFIG_X86_64 because of the way that the memory map might be
configured as detailed in the following bug report,

	https://bugzilla.redhat.com/show_bug.cgi?id=748516

e.g. some of the EFI memory regions *need* to be mapped as part
of the direct kernel mapping.

Signed-off-by: Matt Fleming <[email protected]>
Cc: Matthew Garrett <[email protected]>
Cc: Zhang Rui <[email protected]>
Cc: Huang Ying <[email protected]>
Cc: Keith Packard <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Andrew Morton <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
…estroy()

Because ->pre_destroy() could fail and can't be called under
cgroup_mutex, cgroup destruction did something very ugly.

  1. Grab cgroup_mutex and verify it can be destroyed; fail otherwise.

  2. Release cgroup_mutex and call ->pre_destroy().

  3. Re-grab cgroup_mutex and verify it can still be destroyed; fail
     otherwise.

  4. Continue destroying.

In addition to being ugly, it has been always broken in various ways.
For example, memcg ->pre_destroy() expects the cgroup to be inactive
after it's done but tasks can be attached and detached between #2 and
#3 and the conditions that memcg verified in ->pre_destroy() might no
longer hold by the time control reaches #3.

Now that ->pre_destroy() is no longer allowed to fail.  We can switch
to the following.

  1. Grab cgroup_mutex and verify it can be destroyed; fail otherwise.

  2. Deactivate CSS's and mark the cgroup removed thus preventing any
     further operations which can invalidate the verification from #1.

  3. Release cgroup_mutex and call ->pre_destroy().

  4. Re-grab cgroup_mutex and continue destroying.

After this change, controllers can safely assume that ->pre_destroy()
will only be called only once for a given cgroup and, once
->pre_destroy() is called, the cgroup will stay dormant till it's
destroyed.

This removes the only reason ->pre_destroy() can fail - new task being
attached or child cgroup being created inbetween.  Error out path is
removed and ->pre_destroy() invocation is open coded in
cgroup_rmdir().

v2: cgroup_call_pre_destroy() removal moved to this patch per Michal.
    Commit message updated per Glauber.

Signed-off-by: Tejun Heo <[email protected]>
Reviewed-by: Michal Hocko <[email protected]>
Reviewed-by: KAMEZAWA Hiroyuki <[email protected]>
Acked-by: Li Zefan <[email protected]>
Cc: Glauber Costa <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
Rule #3 of kref.txt

Signed-off-by: Philipp Reisner <[email protected]>
Signed-off-by: Lars Ellenberg <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
Errata Titles:
i103: Delay needed to read some GP timer, WD timer and sync timer
      registers after wakeup (OMAP3/4)
i767: Delay needed to read some GP timer registers after wakeup (OMAP5)

Description (i103/i767):
If a General Purpose Timer (GPTimer) is in posted mode
(TSICR [2].POSTED=1), due to internal resynchronizations, values read in
TCRR, TCAR1 and TCAR2 registers right after the timer interface clock
(L4) goes from stopped to active may not return the expected values. The
most common event leading to this situation occurs upon wake up from
idle.

GPTimer non-posted synchronization mode is not impacted by this
limitation.

Workarounds:
1). Disable posted mode
2). Use static dependency between timer clock domain and MPUSS clock
    domain
3). Use no-idle mode when the timer is active

Workarounds #2 and #3 are not pratical from a power standpoint and so
workaround #1 has been implemented. Disabling posted mode adds some CPU
overhead for configuring and reading the timers as the CPU has to wait
for accesses to be re-synchronised within the timer. However, disabling
posted mode guarantees correct operation.

Please note that it is safe to use posted mode for timers if the counter
(TCRR) and capture (TCARx) registers will never be read. An example of
this is the clock-event system timer. This is used by the kernel to
schedule events however, the timers counter is never read and capture
registers are not used. Given that the kernel configures this timer
often yet never reads the counter register it is safe to enable posted
mode in this case. Hence, for the timer used for kernel clock-events,
posted mode is enabled by overriding the errata for devices that are
impacted by this defect.

For drivers using the timers that do not read the counter or capture
registers and wish to use posted mode, can override the errata and
enable posted mode by making the following function calls.

	__omap_dm_timer_override_errata(timer, OMAP_TIMER_ERRATA_I103_I767);
	__omap_dm_timer_enable_posted(timer);

Both dmtimers and watchdogs are impacted by this defect this patch only
implements the workaround for the dmtimer. Currently the watchdog driver
does not read the counter register and so no workaround is necessary.

Posted mode will be disabled for all OMAP2+ devices (including AM33xx)
using a GP timer as a clock-source timer to guarantee correct operation.
This is not necessary for OMAP24xx devices but the default clock-source
timer for OMAP24xx devices is the 32k-sync timer and not the GP timer
and so should not have any impact. This should be re-visited for future
devices if this errata is fixed.

Confirmed with Vaibhav Hiremath that this bug also impacts AM33xx
devices.

Signed-off-by: Jon Hunter <[email protected]>
Acked-by: Santosh Shilimkar <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
When sched_show_task() is invoked from try_to_freeze_tasks(), there is
no RCU read-side critical section, resulting in the following splat:

[  125.780730] ===============================
[  125.780766] [ INFO: suspicious RCU usage. ]
[  125.780804] 3.7.0-rc3+ torvalds#988 Not tainted
[  125.780838] -------------------------------
[  125.780875] /home/rafael/src/linux/kernel/sched/core.c:4497 suspicious rcu_dereference_check() usage!
[  125.780946]
[  125.780946] other info that might help us debug this:
[  125.780946]
[  125.781031]
[  125.781031] rcu_scheduler_active = 1, debug_locks = 0
[  125.781087] 4 locks held by s2ram/4211:
[  125.781120]  #0:  (&buffer->mutex){+.+.+.}, at: [<ffffffff811e2acf>] sysfs_write_file+0x3f/0x160
[  125.781233]  #1:  (s_active#94){.+.+.+}, at: [<ffffffff811e2b58>] sysfs_write_file+0xc8/0x160
[  125.781339]  #2:  (pm_mutex){+.+.+.}, at: [<ffffffff81090a81>] pm_suspend+0x81/0x230
[  125.781439]  #3:  (tasklist_lock){.?.?..}, at: [<ffffffff8108feed>] try_to_freeze_tasks+0x2cd/0x3f0
[  125.781543]
[  125.781543] stack backtrace:
[  125.781584] Pid: 4211, comm: s2ram Not tainted 3.7.0-rc3+ torvalds#988
[  125.781632] Call Trace:
[  125.781662]  [<ffffffff810a3c73>] lockdep_rcu_suspicious+0x103/0x140
[  125.781719]  [<ffffffff8107cf21>] sched_show_task+0x121/0x180
[  125.781770]  [<ffffffff8108ffb4>] try_to_freeze_tasks+0x394/0x3f0
[  125.781823]  [<ffffffff810903b5>] freeze_kernel_threads+0x25/0x80
[  125.781876]  [<ffffffff81090b65>] pm_suspend+0x165/0x230
[  125.781924]  [<ffffffff8108fa29>] state_store+0x99/0x100
[  125.781975]  [<ffffffff812f5867>] kobj_attr_store+0x17/0x20
[  125.782038]  [<ffffffff811e2b71>] sysfs_write_file+0xe1/0x160
[  125.782091]  [<ffffffff811667a6>] vfs_write+0xc6/0x180
[  125.782138]  [<ffffffff81166ada>] sys_write+0x5a/0xa0
[  125.782185]  [<ffffffff812ff6ae>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[  125.782242]  [<ffffffff81669dd2>] system_call_fastpath+0x16/0x1b

This commit therefore adds the needed RCU read-side critical section.

Reported-by: "Rafael J. Wysocki" <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
cgroup_create_dir() does weird dancing with dentry refcnt.  On
success, it gets and then puts it achieving nothing.  On failure, it
puts but there isn't no matching get anywhere leading to the following
oops if cgroup_create_file() fails for whatever reason.

  ------------[ cut here ]------------
  kernel BUG at /work/os/work/fs/dcache.c:552!
  invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
  Modules linked in:
  CPU 2
  Pid: 697, comm: mkdir Not tainted 3.7.0-rc4-work+ #3 Bochs Bochs
  RIP: 0010:[<ffffffff811d9c0c>]  [<ffffffff811d9c0c>] dput+0x1dc/0x1e0
  RSP: 0018:ffff88001a3ebef8  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff88000e5b1ef8 RCX: 0000000000000403
  RDX: 0000000000000303 RSI: 2000000000000000 RDI: ffff88000e5b1f58
  RBP: ffff88001a3ebf18 R08: ffffffff82c76960 R09: 0000000000000001
  R10: ffff880015022080 R11: ffd9bed70f48a041 R12: 00000000ffffffea
  R13: 0000000000000001 R14: ffff88000e5b1f58 R15: 00007fff57656d60
  FS:  00007ff05fcb3800(0000) GS:ffff88001fd00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000004046f0 CR3: 000000001315f000 CR4: 00000000000006e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process mkdir (pid: 697, threadinfo ffff88001a3ea000, task ffff880015022080)
  Stack:
   ffff88001a3ebf48 00000000ffffffea 0000000000000001 0000000000000000
   ffff88001a3ebf38 ffffffff811cc889 0000000000000001 ffff88000e5b1ef8
   ffff88001a3ebf68 ffffffff811d1fc9 ffff8800198d7f18 ffff880019106ef8
  Call Trace:
   [<ffffffff811cc889>] done_path_create+0x19/0x50
   [<ffffffff811d1fc9>] sys_mkdirat+0x59/0x80
   [<ffffffff811d2009>] sys_mkdir+0x19/0x20
   [<ffffffff81be1e02>] system_call_fastpath+0x16/0x1b
  Code: 00 48 8d 90 18 01 00 00 48 89 93 c0 00 00 00 4c 89 a0 18 01 00 00 48 8b 83 a0 00 00 00 83 80 28 01 00 00 01 e8 e6 6f a0 00 eb 92 <0f> 0b 66 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 49 89 fe 41
  RIP  [<ffffffff811d9c0c>] dput+0x1dc/0x1e0
   RSP <ffff88001a3ebef8>
  ---[ end trace 1277bcfd9561ddb0 ]---

Fix it by dropping the unnecessary dget/dput() pair.

Signed-off-by: Tejun Heo <[email protected]>
Acked-by: Li Zefan <[email protected]>
Cc: [email protected]
mitake pushed a commit that referenced this issue Jan 12, 2014
An earlier commit cd00608 ("ata_piix:
defer disks to the Hyper-V drivers by default") broke MS Virtual PC
guests. Hyper-V guests and Virtual PC guests have nearly identical DMI
info. As a result the driver does currently ignore the emulated hardware
in Virtual PC guests and defers the handling to hv_blkvsc. Since Virtual
PC does not offer paravirtualized drivers no disks will be found in the
guest.

One difference in the DMI info is the product version. This patch adds a
match for MS Virtual PC 2007 and "unignores" the emulated hardware.

This was reported for openSuSE 12.1 in bugzilla:
https://bugzilla.novell.com/show_bug.cgi?id=737532

Here is a detailed list of DMI info from example guests:

hwinfo --bios:

virtual pc guest:

  System Info: #1
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "VS2005R2"
    Serial: "3178-9905-1533-4840-9282-0569-59"
    UUID: undefined, but settable
    Wake-up: 0x06 (Power Switch)
  Board Info: #2
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "5.0"
    Serial: "3178-9905-1533-4840-9282-0569-59"
  Chassis Info: #3
    Manufacturer: "Microsoft Corporation"
    Version: "5.0"
    Serial: "3178-9905-1533-4840-9282-0569-59"
    Asset Tag: "7188-3705-6309-9738-9645-0364-00"
    Type: 0x03 (Desktop)
    Bootup State: 0x03 (Safe)
    Power Supply State: 0x03 (Safe)
    Thermal State: 0x01 (Other)
    Security Status: 0x01 (Other)

win2k8 guest:

  System Info: #1
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "7.0"
    Serial: "9106-3420-9819-5495-1514-2075-48"
    UUID: undefined, but settable
    Wake-up: 0x06 (Power Switch)
  Board Info: #2
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "7.0"
    Serial: "9106-3420-9819-5495-1514-2075-48"
  Chassis Info: #3
    Manufacturer: "Microsoft Corporation"
    Version: "7.0"
    Serial: "9106-3420-9819-5495-1514-2075-48"
    Asset Tag: "7076-9522-6699-1042-9501-1785-77"
    Type: 0x03 (Desktop)
    Bootup State: 0x03 (Safe)
    Power Supply State: 0x03 (Safe)
    Thermal State: 0x01 (Other)
    Security Status: 0x01 (Other)

win2k12 guest:

  System Info: #1
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "7.0"
    Serial: "8179-1954-0187-0085-3868-2270-14"
    UUID: undefined, but settable
    Wake-up: 0x06 (Power Switch)
  Board Info: #2
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "7.0"
    Serial: "8179-1954-0187-0085-3868-2270-14"
  Chassis Info: #3
    Manufacturer: "Microsoft Corporation"
    Version: "7.0"
    Serial: "8179-1954-0187-0085-3868-2270-14"
    Asset Tag: "8374-0485-4557-6331-0620-5845-25"
    Type: 0x03 (Desktop)
    Bootup State: 0x03 (Safe)
    Power Supply State: 0x03 (Safe)
    Thermal State: 0x01 (Other)
    Security Status: 0x01 (Other)

Signed-off-by: Olaf Hering <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
store_host_reset() has tried to re-invent the wheel to compare sysfs strings.
Unfortunately it did so poorly and never bothered to check the input from
userspace before overwriting stack with it, so something simple as:

echo "WoopsieWoopsie" >
/sys/devices/pseudo_0/adapter0/host0/scsi_host/host0/host_reset

would result in:

[  316.310101] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff81f5bac7
[  316.310101]
[  316.320051] Pid: 6655, comm: sh Tainted: G        W    3.7.0-rc5-next-20121114-sasha-00016-g5c9d68d-dirty torvalds#129
[  316.320051] Call Trace:
[  316.340058] pps pps0: PPS event at 1352918752.620355751
[  316.340062] pps pps0: capture assert seq torvalds#303
[  316.320051]  [<ffffffff83b3856b>] panic+0xcd/0x1f4
[  316.320051]  [<ffffffff81f5bac7>] ? store_host_reset+0xd7/0x100
[  316.320051]  [<ffffffff8110b996>] __stack_chk_fail+0x16/0x20
[  316.320051]  [<ffffffff81f5bac7>] store_host_reset+0xd7/0x100
[  316.320051]  [<ffffffff81e55bb3>] dev_attr_store+0x13/0x30
[  316.320051]  [<ffffffff812f7db1>] sysfs_write_file+0x101/0x170
[  316.320051]  [<ffffffff8127acc8>] vfs_write+0xb8/0x180
[  316.320051]  [<ffffffff8127ae80>] sys_write+0x50/0xa0
[  316.320051]  [<ffffffff83c03418>] tracesys+0xe1/0xe6

Fix this by uninventing whatever was going on there and just use sysfs_streq.

Bug introduced by 2944369 ("[SCSI] scsi: Added support for adapter and
firmware reset").

[jejb: added necessary const to prevent compile warnings]
Signed-off-by: Sasha Levin <[email protected]>
Cc: <[email protected]> #3.2+
Signed-off-by: James Bottomley <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
…for success and failure.

FC transport on receiving bsg_job submission failure, calls bsg_job->job_done()
and sets the bsg_job->reply->result the returned value. In contrast, when the
success code (0) is returned fc transport doesn't call bsg_job->job_done() and
doesn't populate bsg_job->reply->result.

Signed-off-by: Steve Hodgson <[email protected]>
Signed-off-by: Armen Baloyan <[email protected]>
Signed-off-by: Saurav Kashyap <[email protected]>
Cc: <[email protected]> #3.7
Signed-off-by: James Bottomley <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
… sequence while unloading qla2xxx driver.

Signed-off-by: Giridhar Malavali <[email protected]>
Signed-off-by: Saurav Kashyap <[email protected]>
Cc: <[email protected]> #3.7
Signed-off-by: James Bottomley <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
…ck()

Signed-off-by: Steve Hodgson <[email protected]>
Signed-off-by: Armen Baloyan <[email protected]>
Signed-off-by: Saurav Kashyap <[email protected]>
Cc: <[email protected]> #3.7
Signed-off-by: James Bottomley <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
A rescue thread exiting TASK_INTERRUPTIBLE can lead to a task scheduling
off, never to be seen again.  In the case where this occurred, an exiting
thread hit reiserfs homebrew conditional resched while holding a mutex,
bringing the box to its knees.

PID: 18105  TASK: ffff8807fd412180  CPU: 5   COMMAND: "kdmflush"
 #0 [ffff8808157e7670] schedule at ffffffff8143f489
 #1 [ffff8808157e77b8] reiserfs_get_block at ffffffffa038ab2d [reiserfs]
 #2 [ffff8808157e79a8] __block_write_begin at ffffffff8117fb14
 #3 [ffff8808157e7a98] reiserfs_write_begin at ffffffffa0388695 [reiserfs]
 #4 [ffff8808157e7ad8] generic_perform_write at ffffffff810ee9e2
 #5 [ffff8808157e7b58] generic_file_buffered_write at ffffffff810eeb41
 torvalds#6 [ffff8808157e7ba8] __generic_file_aio_write at ffffffff810f1a3a
 torvalds#7 [ffff8808157e7c58] generic_file_aio_write at ffffffff810f1c88
 torvalds#8 [ffff8808157e7cc8] do_sync_write at ffffffff8114f850
 torvalds#9 [ffff8808157e7dd8] do_acct_process at ffffffff810a268f
    [exception RIP: kernel_thread_helper]
    RIP: ffffffff8144a5c0  RSP: ffff8808157e7f58  RFLAGS: 00000202
    RAX: 0000000000000000  RBX: 0000000000000000  RCX: 0000000000000000
    RDX: 0000000000000000  RSI: ffffffff8107af60  RDI: ffff8803ee491d18
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000000  R12: 0000000000000000
    R13: 0000000000000000  R14: 0000000000000000  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018

Signed-off-by: Mike Galbraith <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
Cc: [email protected]
mitake pushed a commit that referenced this issue Jan 12, 2014
Michael Semon reported that xfs/299 generated this lockdep warning:

=============================================
[ INFO: possible recursive locking detected ]
3.12.0-rc2+ #2 Not tainted
---------------------------------------------
touch/21072 is trying to acquire lock:
 (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64

but task is already holding lock:
 (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64

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

       CPU0
       ----
  lock(&xfs_dquot_other_class);
  lock(&xfs_dquot_other_class);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

7 locks held by touch/21072:
 #0:  (sb_writers#10){++++.+}, at: [<c11185b6>] mnt_want_write+0x1e/0x3e
 #1:  (&type->i_mutex_dir_key#4){+.+.+.}, at: [<c11078ee>] do_last+0x245/0xe40
 #2:  (sb_internal#2){++++.+}, at: [<c122c9e0>] xfs_trans_alloc+0x1f/0x35
 #3:  (&(&ip->i_lock)->mr_lock/1){+.+...}, at: [<c126cd1b>] xfs_ilock+0x100/0x1f1
 #4:  (&(&ip->i_lock)->mr_lock){++++-.}, at: [<c126cf52>] xfs_ilock_nowait+0x105/0x22f
 #5:  (&dqp->q_qlock){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64
 torvalds#6:  (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64

The lockdep annotation for dquot lock nesting only understands
locking for user and "other" dquots, not user, group and quota
dquots. Fix the annotations to match the locking heirarchy we now
have.

Reported-by: Michael L. Semon <[email protected]>
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Ben Myers <[email protected]>
Signed-off-by: Ben Myers <[email protected]>

(cherry picked from commit f112a04)
mitake pushed a commit that referenced this issue Jan 12, 2014
->needs_read_fill is used to implement the following behaviors.

1. Ensure buffer filling on the first read.
2. Force buffer filling after a write.
3. Force buffer filling after a successful poll.

However, #2 and #3 don't really work as sysfs doesn't reset file
position.  While the read buffer would be refilled, the next read
would continue from the position after the last read or write,
requiring an explicit seek to the start for it to be useful, which
makes ->needs_read_fill superflous as read buffer is always refilled
if f_pos == 0.

Update sysfs_read_file() to test buffer->page for #1 instead and
remove ->needs_read_fill.  While this changes behavior in extreme
corner cases - e.g. re-reading a sysfs file after seeking to non-zero
position after a write or poll, it's highly unlikely to lead to actual
breakage.  This change is to prepare for using seq_file in the read
path.

While at it, reformat a comment in fill_write_buffer().

Signed-off-by: Tejun Heo <[email protected]>
Cc: Kay Sievers <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
Booting a mx6 with CONFIG_PROVE_LOCKING we get:

======================================================
[ INFO: possible circular locking dependency detected ]
3.12.0-rc4-next-20131009+ torvalds#34 Not tainted
-------------------------------------------------------
swapper/0/1 is trying to acquire lock:
 (&imx_drm_device->mutex){+.+.+.}, at: [<804575a8>] imx_drm_encoder_get_mux_id+0x28/0x98

but task is already holding lock:
 (&crtc->mutex){+.+...}, at: [<802fe778>] drm_modeset_lock_all+0x40/0x54

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&crtc->mutex){+.+...}:
       [<800777d0>] __lock_acquire+0x18d4/0x1c24
       [<80077fec>] lock_acquire+0x68/0x7c
       [<805ead5c>] _mutex_lock_nest_lock+0x58/0x3a8
       [<802fec50>] drm_crtc_init+0x48/0xa8
       [<80457c88>] imx_drm_add_crtc+0xd4/0x144
       [<8045e2e8>] ipu_drm_probe+0x114/0x1fc
       [<80312278>] platform_drv_probe+0x20/0x50
       [<80310c68>] driver_probe_device+0x110/0x22c
       [<80310e20>] __driver_attach+0x9c/0xa0
       [<8030f218>] bus_for_each_dev+0x5c/0x90
       [<80310750>] driver_attach+0x20/0x28
       [<8031034c>] bus_add_driver+0xdc/0x1dc
       [<803114d8>] driver_register+0x80/0xfc
       [<80312198>] __platform_driver_register+0x50/0x64
       [<808172fc>] ipu_drm_driver_init+0x18/0x20
       [<800088c0>] do_one_initcall+0xfc/0x160
       [<807e7c5c>] kernel_init_freeable+0x104/0x1d4
       [<805e2930>] kernel_init+0x10/0xec
       [<8000ea68>] ret_from_fork+0x14/0x2c

-> #1 (&dev->mode_config.mutex){+.+.+.}:
       [<800777d0>] __lock_acquire+0x18d4/0x1c24
       [<80077fec>] lock_acquire+0x68/0x7c
       [<805eb100>] mutex_lock_nested+0x54/0x3a4
       [<802fe758>] drm_modeset_lock_all+0x20/0x54
       [<802fead4>] drm_encoder_init+0x20/0x7c
       [<80457ae4>] imx_drm_add_encoder+0x88/0xec
       [<80459838>] imx_ldb_probe+0x344/0x4fc
       [<80312278>] platform_drv_probe+0x20/0x50
       [<80310c68>] driver_probe_device+0x110/0x22c
       [<80310e20>] __driver_attach+0x9c/0xa0
       [<8030f218>] bus_for_each_dev+0x5c/0x90
       [<80310750>] driver_attach+0x20/0x28
       [<8031034c>] bus_add_driver+0xdc/0x1dc
       [<803114d8>] driver_register+0x80/0xfc
       [<80312198>] __platform_driver_register+0x50/0x64
       [<8081722c>] imx_ldb_driver_init+0x18/0x20
       [<800088c0>] do_one_initcall+0xfc/0x160
       [<807e7c5c>] kernel_init_freeable+0x104/0x1d4
       [<805e2930>] kernel_init+0x10/0xec
       [<8000ea68>] ret_from_fork+0x14/0x2c

-> #0 (&imx_drm_device->mutex){+.+.+.}:
       [<805e510c>] print_circular_bug+0x74/0x2e0
       [<80077ad0>] __lock_acquire+0x1bd4/0x1c24
       [<80077fec>] lock_acquire+0x68/0x7c
       [<805eb100>] mutex_lock_nested+0x54/0x3a4
       [<804575a8>] imx_drm_encoder_get_mux_id+0x28/0x98
       [<80459a98>] imx_ldb_encoder_prepare+0x34/0x114
       [<802ef724>] drm_crtc_helper_set_mode+0x1f0/0x4c0
       [<802f0344>] drm_crtc_helper_set_config+0x828/0x99c
       [<802ff270>] drm_mode_set_config_internal+0x5c/0xdc
       [<802eebe0>] drm_fb_helper_set_par+0x50/0xb4
       [<802af580>] fbcon_init+0x490/0x500
       [<802dd104>] visual_init+0xa8/0xf8
       [<802df414>] do_bind_con_driver+0x140/0x37c
       [<802df764>] do_take_over_console+0x114/0x1c4
       [<802af65c>] do_fbcon_takeover+0x6c/0xd4
       [<802b2b30>] fbcon_event_notify+0x7c8/0x818
       [<80049954>] notifier_call_chain+0x4c/0x8c
       [<80049cd8>] __blocking_notifier_call_chain+0x50/0x68
       [<80049d10>] blocking_notifier_call_chain+0x20/0x28
       [<802a75f0>] fb_notifier_call_chain+0x1c/0x24
       [<802a9224>] register_framebuffer+0x188/0x268
       [<802ee994>] drm_fb_helper_initial_config+0x2bc/0x4b8
       [<802f118c>] drm_fbdev_cma_init+0x7c/0xec
       [<80817288>] imx_fb_helper_init+0x54/0x90
       [<800088c0>] do_one_initcall+0xfc/0x160
       [<807e7c5c>] kernel_init_freeable+0x104/0x1d4
       [<805e2930>] kernel_init+0x10/0xec
       [<8000ea68>] ret_from_fork+0x14/0x2c

other info that might help us debug this:

Chain exists of:
  &imx_drm_device->mutex --> &dev->mode_config.mutex --> &crtc->mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&crtc->mutex);
                               lock(&dev->mode_config.mutex);
                               lock(&crtc->mutex);
  lock(&imx_drm_device->mutex);

 *** DEADLOCK ***

6 locks held by swapper/0/1:
 #0:  (registration_lock){+.+.+.}, at: [<802a90bc>] register_framebuffer+0x20/0x268
 #1:  (&fb_info->lock){+.+.+.}, at: [<802a7a90>] lock_fb_info+0x20/0x44
 #2:  (console_lock){+.+.+.}, at: [<802a9218>] register_framebuffer+0x17c/0x268
 #3:  ((fb_notifier_list).rwsem){.+.+.+}, at: [<80049cbc>] __blocking_notifier_call_chain+0x34/0x68
 #4:  (&dev->mode_config.mutex){+.+.+.}, at: [<802fe758>] drm_modeset_lock_all+0x20/0x54
 #5:  (&crtc->mutex){+.+...}, at: [<802fe778>] drm_modeset_lock_all+0x40/0x54

In order to avoid this lockdep warning, remove the locking from
imx_drm_encoder_get_mux_id() and imx_drm_crtc_panel_format_pins().

Tested on a mx6sabrelite and mx53qsb.

Reported-by: Russell King <[email protected]>
Tested-by: Russell King <[email protected]>
Signed-off-by: Fabio Estevam <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
375b611 ("sysfs: remove sysfs_buffer->ops") introduced
sysfs_file_ops() which determines the associated file operation of a
given sysfs_dirent.  As file ops access should be protected by an
active reference, the new function includes a lockdep assertion on the
sysfs_dirent; unfortunately, I forgot to take attr->ignore_lockdep
flag into account and the lockdep assertion trips spuriously for files
which opt out from active reference lockdep checking.

# cat /sys/devices/pci0000:00/0000:00:01.2/usb1/authorized

 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 540 at /work/os/work/fs/sysfs/file.c:79 sysfs_file_ops+0x4e/0x60()
 Modules linked in:
 CPU: 1 PID: 540 Comm: cat Not tainted 3.11.0-work+ #3
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  0000000000000009 ffff880016205c08 ffffffff81ca0131 0000000000000000
  ffff880016205c40 ffffffff81096d0d ffff8800166cb898 ffff8800166f6f60
  ffffffff8125a220 ffff880011ab1ec0 ffff88000aff0c78 ffff880016205c50
 Call Trace:
  [<ffffffff81ca0131>] dump_stack+0x4e/0x82
  [<ffffffff81096d0d>] warn_slowpath_common+0x7d/0xa0
  [<ffffffff81096dea>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8125994e>] sysfs_file_ops+0x4e/0x60
  [<ffffffff8125a274>] sysfs_open_file+0x54/0x300
  [<ffffffff811df612>] do_dentry_open.isra.17+0x182/0x280
  [<ffffffff811df820>] finish_open+0x30/0x40
  [<ffffffff811f0623>] do_last+0x503/0xd90
  [<ffffffff811f0f6b>] path_openat+0xbb/0x6d0
  [<ffffffff811f23ba>] do_filp_open+0x3a/0x90
  [<ffffffff811e09a9>] do_sys_open+0x129/0x220
  [<ffffffff811e0abe>] SyS_open+0x1e/0x20
  [<ffffffff81caf3c2>] system_call_fastpath+0x16/0x1b
 ---[ end trace aa48096b111dafdb ]---

Rename fs/sysfs/dir.c::ignore_lockdep() to sysfs_ignore_lockdep() and
move it to fs/sysfs/sysfs.h and make sysfs_file_ops() skip lockdep
assertion if sysfs_ignore_lockdep() is true.

Signed-off-by: Tejun Heo <[email protected]>
Reported-by: Yinghai Lu <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
If EM Transmit bit is busy during init ata_msleep() is called.  It is
wrong - msleep() should be used instead of ata_msleep(), because if EM
Transmit bit is busy for one port, it will be busy for all other ports
too, so using ata_msleep() causes wasting tries for another ports.

The most common scenario looks like that now
(six ports try to transmit a LED meaasege):
- port #0 tries for the 1st time and succeeds
- ports #1-5 try for the 1st time and sleeps
- port #1 tries for the 2nd time and succeeds
- ports #2-5 try for the 2nd time and sleeps
- port #2 tries for the 3rd time and succeeds
- ports #3-5 try for the 3rd time and sleeps
- port #3 tries for the 4th time and succeeds
- ports #4-5 try for the 4th time and sleeps
- port #4 tries for the 5th time and succeeds
- port #5 tries for the 5th time and sleeps

At this moment port #5 wasted all its five tries and failed to
initialize.  Because there are only 5 (EM_MAX_RETRY) tries available
usually only five ports succeed to initialize. The sixth port and next
ones usually will fail.

If msleep() is used instead of ata_msleep() the first port succeeds to
initialize in the first try and next ones usually succeed to
initialize in the second try.

tj: updated comment

Signed-off-by: Lukasz Dorau <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
… EINVAL

When inserting a wrong value to /sys/devices/system/memory/memoryX/state file,
following messages are shown. And device_hotplug_lock is never released.

================================================
[ BUG: lock held when returning to user space! ]
3.12.0-rc4-debug+ #3 Tainted: G        W
------------------------------------------------
bash/6442 is leaving the kernel with locks still held!
1 lock held by bash/6442:
 #0:  (device_hotplug_lock){+.+.+.}, at: [<ffffffff8146cbb5>] lock_device_hotplug_sysfs+0x15/0x50

This issue was introdued by commit fa2be40 (drivers: base: use standard
device online/offline for state change).

This patch releases device_hotplug_lcok when store_mem_state returns EINVAL.

Signed-off-by: Yasuaki Ishimatsu <[email protected]>
Reviewed-by: Toshi Kani <[email protected]>
CC: Seth Jennings <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
Fix random kernel panic with below messages when remove dongle.

[ 2212.355447] BUG: unable to handle kernel NULL pointer dereference at 0000000000000250
[ 2212.355527] IP: [<ffffffffa02667f2>] rt2x00usb_kick_tx_entry+0x12/0x160 [rt2x00usb]
[ 2212.355599] PGD 0
[ 2212.355626] Oops: 0000 [#1] SMP
[ 2212.355664] Modules linked in: rt2800usb rt2x00usb rt2800lib crc_ccitt rt2x00lib mac80211 cfg80211 tun arc4 fuse rfcomm bnep snd_hda_codec_realtek snd_hda_intel snd_hda_codec btusb uvcvideo bluetooth snd_hwdep x86_pkg_temp_thermal snd_seq coretemp aesni_intel aes_x86_64 snd_seq_device glue_helper snd_pcm ablk_helper videobuf2_vmalloc sdhci_pci videobuf2_memops videobuf2_core sdhci videodev mmc_core serio_raw snd_page_alloc microcode i2c_i801 snd_timer hid_multitouch thinkpad_acpi lpc_ich mfd_core snd tpm_tis wmi tpm tpm_bios soundcore acpi_cpufreq i915 i2c_algo_bit drm_kms_helper drm i2c_core video [last unloaded: cfg80211]
[ 2212.356224] CPU: 0 PID: 34 Comm: khubd Not tainted 3.12.0-rc3-wl+ #3
[ 2212.356268] Hardware name: LENOVO 3444CUU/3444CUU, BIOS G6ET93WW (2.53 ) 02/04/2013
[ 2212.356319] task: ffff880212f687c0 ti: ffff880212f66000 task.ti: ffff880212f66000
[ 2212.356392] RIP: 0010:[<ffffffffa02667f2>]  [<ffffffffa02667f2>] rt2x00usb_kick_tx_entry+0x12/0x160 [rt2x00usb]
[ 2212.356481] RSP: 0018:ffff880212f67750  EFLAGS: 00010202
[ 2212.356519] RAX: 000000000000000c RBX: 000000000000000c RCX: 0000000000000293
[ 2212.356568] RDX: ffff8801f4dc219a RSI: 0000000000000000 RDI: 0000000000000240
[ 2212.356617] RBP: ffff880212f67778 R08: ffffffffa02667e0 R09: 0000000000000002
[ 2212.356665] R10: 0001f95254ab4b40 R11: ffff880212f675be R12: ffff8801f4dc2150
[ 2212.356712] R13: 0000000000000000 R14: ffffffffa02667e0 R15: 000000000000000d
[ 2212.356761] FS:  0000000000000000(0000) GS:ffff88021e200000(0000) knlGS:0000000000000000
[ 2212.356813] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2212.356852] CR2: 0000000000000250 CR3: 0000000001a0c000 CR4: 00000000001407f0
[ 2212.356899] Stack:
[ 2212.356917]  000000000000000c ffff8801f4dc2150 0000000000000000 ffffffffa02667e0
[ 2212.356980]  000000000000000d ffff880212f677b8 ffffffffa03a31ad ffff8801f4dc219a
[ 2212.357038]  ffff8801f4dc2150 0000000000000000 ffff8800b93217a0 ffff8801f49bc800
[ 2212.357099] Call Trace:
[ 2212.357122]  [<ffffffffa02667e0>] ? rt2x00usb_interrupt_txdone+0x90/0x90 [rt2x00usb]
[ 2212.357174]  [<ffffffffa03a31ad>] rt2x00queue_for_each_entry+0xed/0x170 [rt2x00lib]
[ 2212.357244]  [<ffffffffa026701c>] rt2x00usb_kick_queue+0x5c/0x60 [rt2x00usb]
[ 2212.357314]  [<ffffffffa03a3682>] rt2x00queue_flush_queue+0x62/0xa0 [rt2x00lib]
[ 2212.357386]  [<ffffffffa03a2930>] rt2x00mac_flush+0x30/0x70 [rt2x00lib]
[ 2212.357470]  [<ffffffffa04edded>] ieee80211_flush_queues+0xbd/0x140 [mac80211]
[ 2212.357555]  [<ffffffffa0502e52>] ieee80211_set_disassoc+0x2d2/0x3d0 [mac80211]
[ 2212.357645]  [<ffffffffa0506da3>] ieee80211_mgd_deauth+0x1d3/0x240 [mac80211]
[ 2212.357718]  [<ffffffff8108b17c>] ? try_to_wake_up+0xec/0x290
[ 2212.357788]  [<ffffffffa04dbd18>] ieee80211_deauth+0x18/0x20 [mac80211]
[ 2212.357872]  [<ffffffffa0418ddc>] cfg80211_mlme_deauth+0x9c/0x140 [cfg80211]
[ 2212.357913]  [<ffffffffa041907c>] cfg80211_mlme_down+0x5c/0x60 [cfg80211]
[ 2212.357962]  [<ffffffffa041cd18>] cfg80211_disconnect+0x188/0x1a0 [cfg80211]
[ 2212.358014]  [<ffffffffa04013bc>] ? __cfg80211_stop_sched_scan+0x1c/0x130 [cfg80211]
[ 2212.358067]  [<ffffffffa03f8954>] cfg80211_leave+0xc4/0xe0 [cfg80211]
[ 2212.358124]  [<ffffffffa03f8d1b>] cfg80211_netdev_notifier_call+0x3ab/0x5e0 [cfg80211]
[ 2212.358177]  [<ffffffff815140f8>] ? inetdev_event+0x38/0x510
[ 2212.358217]  [<ffffffff81085a94>] ? __wake_up+0x44/0x50
[ 2212.358254]  [<ffffffff8155995c>] notifier_call_chain+0x4c/0x70
[ 2212.358293]  [<ffffffff81081156>] raw_notifier_call_chain+0x16/0x20
[ 2212.358361]  [<ffffffff814b6dd5>] call_netdevice_notifiers_info+0x35/0x60
[ 2212.358429]  [<ffffffff814b6ec9>] __dev_close_many+0x49/0xd0
[ 2212.358487]  [<ffffffff814b7028>] dev_close_many+0x88/0x100
[ 2212.358546]  [<ffffffff814b8150>] rollback_registered_many+0xb0/0x220
[ 2212.358612]  [<ffffffff814b8319>] unregister_netdevice_many+0x19/0x60
[ 2212.358694]  [<ffffffffa04d8eb2>] ieee80211_remove_interfaces+0x112/0x190 [mac80211]
[ 2212.358791]  [<ffffffffa04c585f>] ieee80211_unregister_hw+0x4f/0x100 [mac80211]
[ 2212.361994]  [<ffffffffa03a1221>] rt2x00lib_remove_dev+0x161/0x1a0 [rt2x00lib]
[ 2212.365240]  [<ffffffffa0266e2e>] rt2x00usb_disconnect+0x2e/0x70 [rt2x00usb]
[ 2212.368470]  [<ffffffff81419ce4>] usb_unbind_interface+0x64/0x1c0
[ 2212.371734]  [<ffffffff813b446f>] __device_release_driver+0x7f/0xf0
[ 2212.374999]  [<ffffffff813b4503>] device_release_driver+0x23/0x30
[ 2212.378131]  [<ffffffff813b3c98>] bus_remove_device+0x108/0x180
[ 2212.381358]  [<ffffffff813b0565>] device_del+0x135/0x1d0
[ 2212.384454]  [<ffffffff81417760>] usb_disable_device+0xb0/0x270
[ 2212.387451]  [<ffffffff8140d9cd>] usb_disconnect+0xad/0x1d0
[ 2212.390294]  [<ffffffff8140f6cd>] hub_thread+0x63d/0x1660
[ 2212.393034]  [<ffffffff8107c860>] ? wake_up_atomic_t+0x30/0x30
[ 2212.395728]  [<ffffffff8140f090>] ? hub_port_debounce+0x130/0x130
[ 2212.398412]  [<ffffffff8107baa0>] kthread+0xc0/0xd0
[ 2212.401058]  [<ffffffff8107b9e0>] ? insert_kthread_work+0x40/0x40
[ 2212.403639]  [<ffffffff8155de3c>] ret_from_fork+0x7c/0xb0
[ 2212.406193]  [<ffffffff8107b9e0>] ? insert_kthread_work+0x40/0x40
[ 2212.408732] Code: 24 58 08 00 00 bf 80 00 00 00 e8 3a c3 e0 e0 5b 41 5c 5d c3 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 <48> 8b 47 10 48 89 fb 4c 8b 6f 28 4c 8b 20 49 8b 04 24 4c 8b 30
[ 2212.414671] RIP  [<ffffffffa02667f2>] rt2x00usb_kick_tx_entry+0x12/0x160 [rt2x00usb]
[ 2212.417646]  RSP <ffff880212f67750>
[ 2212.420547] CR2: 0000000000000250
[ 2212.441024] ---[ end trace 5442918f33832bce ]---

Cc: [email protected]
Signed-off-by: Stanislaw Gruszka <[email protected]>
Acked-by: Helmut Schaa <[email protected]>
Signed-off-by: John W. Linville <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
Fedora Ruby maintainer reported latest Ruby doesn't work on Fedora Rawhide
on ARM. (http://bugs.ruby-lang.org/issues/9008)

Because of, commit 1c6b39a (alarmtimers: Return -ENOTSUPP if no
RTC device is present) intruduced to return ENOTSUPP when
clock_get{time,res} can't find a RTC device. However this is incorrect.

First, ENOTSUPP isn't exported to userland (ENOTSUP or EOPNOTSUP are the
closest userland equivlents).

Second, Posix and Linux man pages agree that clock_gettime and
clock_getres should return EINVAL if clk_id argument is invalid.
While the arugment that the clockid is valid, but just not supported
on this hardware could be made, this is just a technicality that
doesn't help userspace applicaitons, and only complicates error
handling.

Thus, this patch changes the code to use EINVAL.

Cc: Thomas Gleixner <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: stable <[email protected]>  #3.0 and up
Reported-by: Vit Ondruch <[email protected]>
Signed-off-by: KOSAKI Motohiro <[email protected]>
[jstultz: Tweaks to commit message to include full rational]
Signed-off-by: John Stultz <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
Andrey reported the following report:

ERROR: AddressSanitizer: heap-buffer-overflow on address ffff8800359c99f3
ffff8800359c99f3 is located 0 bytes to the right of 243-byte region [ffff8800359c9900, ffff8800359c99f3)
Accessed by thread T13003:
  #0 ffffffff810dd2da (asan_report_error+0x32a/0x440)
  #1 ffffffff810dc6b0 (asan_check_region+0x30/0x40)
  #2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20)
  #3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260)
  #4 ffffffff812a1065 (__fput+0x155/0x360)
  #5 ffffffff812a12de (____fput+0x1e/0x30)
  torvalds#6 ffffffff8111708d (task_work_run+0x10d/0x140)
  torvalds#7 ffffffff810ea043 (do_exit+0x433/0x11f0)
  torvalds#8 ffffffff810eaee4 (do_group_exit+0x84/0x130)
  torvalds#9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30)
  torvalds#10 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Allocated by thread T5167:
  #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0)
  #1 ffffffff8128337c (__kmalloc+0xbc/0x500)
  #2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90)
  #3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0)
  #4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40)
  #5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430)
  torvalds#6 ffffffff8129b668 (finish_open+0x68/0xa0)
  torvalds#7 ffffffff812b66ac (do_last+0xb8c/0x1710)
  torvalds#8 ffffffff812b7350 (path_openat+0x120/0xb50)
  torvalds#9 ffffffff812b8884 (do_filp_open+0x54/0xb0)
  torvalds#10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0)
  torvalds#11 ffffffff8129d4b7 (SyS_open+0x37/0x50)
  torvalds#12 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Shadow bytes around the buggy address:
  ffff8800359c9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  ffff8800359c9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa
  ffff8800359c9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9880: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>ffff8800359c9980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[03]fb
  ffff8800359c9a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9b00: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
  ffff8800359c9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff8800359c9c00: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap redzone:          fa
  Heap kmalloc redzone:  fb
  Freed heap region:     fd
  Shadow gap:            fe

The out-of-bounds access happens on 'parser->buffer[parser->idx] = 0;'

Although the crash happened in ftrace_regex_open() the real bug
occurred in trace_get_user() where there's an incrementation to
parser->idx without a check against the size. The way it is triggered
is if userspace sends in 128 characters (EVENT_BUF_SIZE + 1), the loop
that reads the last character stores it and then breaks out because
there is no more characters. Then the last character is read to determine
what to do next, and the index is incremented without checking size.

Then the caller of trace_get_user() usually nulls out the last character
with a zero, but since the index is equal to the size, it writes a nul
character after the allocated space, which can corrupt memory.

Luckily, only root user has write access to this file.

Link: http://lkml.kernel.org/r/[email protected]

Reported-by: Andrey Konovalov <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
…pacing

When interrupt pacing is enabled, receive/transmit statistics are not
updated properly by hardware which leads to ISR return with IRQ_NONE
and inturn kernel disables the interrupt. This patch removed the checking
of receive/transmit statistics from ISR.

This patch is verified with AM335x Beagle Bone Black and below is the
kernel warn when interrupt pacing is enabled.

[  104.298254] irq 58: nobody cared (try booting with the "irqpoll" option)
[  104.305356] CPU: 0 PID: 1073 Comm: iperf Not tainted 3.12.0-rc3-00342-g77d4015 #3
[  104.313284] [<c001bb84>] (unwind_backtrace+0x0/0xf0) from [<c0017db0>] (show_stack+0x10/0x14)
[  104.322282] [<c0017db0>] (show_stack+0x10/0x14) from [<c0507920>] (dump_stack+0x78/0x94)
[  104.330816] [<c0507920>] (dump_stack+0x78/0x94) from [<c0088c1c>] (__report_bad_irq+0x20/0xc0)
[  104.339889] [<c0088c1c>] (__report_bad_irq+0x20/0xc0) from [<c008912c>] (note_interrupt+0x1dc/0x23c)
[  104.349505] [<c008912c>] (note_interrupt+0x1dc/0x23c) from [<c0086d74>] (handle_irq_event_percpu+0xc4/0x238)
[  104.359851] [<c0086d74>] (handle_irq_event_percpu+0xc4/0x238) from [<c0086f24>] (handle_irq_event+0x3c/0x5c)
[  104.370198] [<c0086f24>] (handle_irq_event+0x3c/0x5c) from [<c008991c>] (handle_level_irq+0xac/0x10c)
[  104.379907] [<c008991c>] (handle_level_irq+0xac/0x10c) from [<c00866d8>] (generic_handle_irq+0x20/0x30)
[  104.389812] [<c00866d8>] (generic_handle_irq+0x20/0x30) from [<c0014ce8>] (handle_IRQ+0x4c/0xb0)
[  104.399066] [<c0014ce8>] (handle_IRQ+0x4c/0xb0) from [<c000856c>] (omap3_intc_handle_irq+0x60/0x74)
[  104.408598] [<c000856c>] (omap3_intc_handle_irq+0x60/0x74) from [<c050d8e4>] (__irq_svc+0x44/0x5c)
[  104.418021] Exception stack(0xde4f7c00 to 0xde4f7c48)
[  104.423345] 7c00: 00000001 00000000 00000000 dd002140 60000013 de006e54 00000002 00000000
[  104.431952] 7c20: de345748 00000040 c11c8588 00018ee0 00000000 de4f7c48 c009dfc8 c050d300
[  104.440553] 7c40: 60000013 ffffffff
[  104.444237] [<c050d8e4>] (__irq_svc+0x44/0x5c) from [<c050d300>] (_raw_spin_unlock_irqrestore+0x34/0x44)
[  104.454220] [<c050d300>] (_raw_spin_unlock_irqrestore+0x34/0x44) from [<c00868c0>] (__irq_put_desc_unlock+0x14/0x38)
[  104.465295] [<c00868c0>] (__irq_put_desc_unlock+0x14/0x38) from [<c0088068>] (enable_irq+0x4c/0x74)
[  104.474829] [<c0088068>] (enable_irq+0x4c/0x74) from [<c03abd24>] (cpsw_poll+0xb8/0xdc)
[  104.483276] [<c03abd24>] (cpsw_poll+0xb8/0xdc) from [<c044ef68>] (net_rx_action+0xc0/0x1e8)
[  104.492085] [<c044ef68>] (net_rx_action+0xc0/0x1e8) from [<c0048a90>] (__do_softirq+0x100/0x27c)
[  104.501338] [<c0048a90>] (__do_softirq+0x100/0x27c) from [<c0048cd0>] (do_softirq+0x68/0x70)
[  104.510224] [<c0048cd0>] (do_softirq+0x68/0x70) from [<c0048e8c>] (local_bh_enable+0xd0/0xe4)
[  104.519211] [<c0048e8c>] (local_bh_enable+0xd0/0xe4) from [<c048c774>] (tcp_rcv_established+0x450/0x648)
[  104.529201] [<c048c774>] (tcp_rcv_established+0x450/0x648) from [<c0494904>] (tcp_v4_do_rcv+0x154/0x474)
[  104.539195] [<c0494904>] (tcp_v4_do_rcv+0x154/0x474) from [<c043d750>] (release_sock+0xac/0x1ac)
[  104.548448] [<c043d750>] (release_sock+0xac/0x1ac) from [<c04844e8>] (tcp_recvmsg+0x4d0/0xa8c)
[  104.557528] [<c04844e8>] (tcp_recvmsg+0x4d0/0xa8c) from [<c04a8720>] (inet_recvmsg+0xcc/0xf0)
[  104.566507] [<c04a8720>] (inet_recvmsg+0xcc/0xf0) from [<c0439744>] (sock_recvmsg+0x90/0xb0)
[  104.575394] [<c0439744>] (sock_recvmsg+0x90/0xb0) from [<c043b778>] (SyS_recvfrom+0x88/0xd8)
[  104.584280] [<c043b778>] (SyS_recvfrom+0x88/0xd8) from [<c043b7e0>] (sys_recv+0x18/0x20)
[  104.592805] [<c043b7e0>] (sys_recv+0x18/0x20) from [<c0013da0>] (ret_fast_syscall+0x0/0x48)
[  104.601587] handlers:
[  104.603992] [<c03acd94>] cpsw_interrupt
[  104.608040] Disabling IRQ #58

Cc: Sebastian Siewior <[email protected]>
Signed-off-by: Mugunthan V N <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
_nfs4_opendata_reclaim_to_nfs4_state doesn't expect to see a cached
open CLAIM_PREVIOUS, but this can happen. An example is when there are
RDWR openers and RDONLY openers on a delegation stateid. The recovery
path will first try an open CLAIM_PREVIOUS for the RDWR openers, this
marks the delegation as not needing RECLAIM anymore, so the open
CLAIM_PREVIOUS for the RDONLY openers will not actually send an rpc.

The NULL dereference is due to _nfs4_opendata_reclaim_to_nfs4_state
returning PTR_ERR(rpc_status) when !rpc_done. When the open is
cached, rpc_done == 0 and rpc_status == 0, thus
_nfs4_opendata_reclaim_to_nfs4_state returns NULL - this is unexpected
by callers of nfs4_opendata_to_nfs4_state().

This can be reproduced easily by opening the same file two times on an
NFSv4.0 mount with delegations enabled, once as RDWR and once as RDONLY then
sleeping for a long time.  While the files are held open, kick off state
recovery and this NULL dereference will be hit every time.

An example OOPS:

[   65.003602] BUG: unable to handle kernel NULL pointer dereference at 00000000
00000030
[   65.005312] IP: [<ffffffffa037d6ee>] __nfs4_close+0x1e/0x160 [nfsv4]
[   65.006820] PGD 7b0ea067 PUD 791ff067 PMD 0
[   65.008075] Oops: 0000 [#1] SMP
[   65.008802] Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache
snd_ens1371 gameport nfsd snd_rawmidi snd_ac97_codec ac97_bus btusb snd_seq snd
_seq_device snd_pcm ppdev bluetooth auth_rpcgss coretemp snd_page_alloc crc32_pc
lmul crc32c_intel ghash_clmulni_intel microcode rfkill nfs_acl vmw_balloon serio
_raw snd_timer lockd parport_pc e1000 snd soundcore parport i2c_piix4 shpchp vmw
_vmci sunrpc ata_generic mperf pata_acpi mptspi vmwgfx ttm scsi_transport_spi dr
m mptscsih mptbase i2c_core
[   65.018684] CPU: 0 PID: 473 Comm: 192.168.10.85-m Not tainted 3.11.2-201.fc19
.x86_64 #1
[   65.020113] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop
Reference Platform, BIOS 6.00 07/31/2013
[   65.022012] task: ffff88003707e320 ti: ffff88007b906000 task.ti: ffff88007b906000
[   65.023414] RIP: 0010:[<ffffffffa037d6ee>]  [<ffffffffa037d6ee>] __nfs4_close+0x1e/0x160 [nfsv4]
[   65.025079] RSP: 0018:ffff88007b907d10  EFLAGS: 00010246
[   65.026042] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   65.027321] RDX: 0000000000000050 RSI: 0000000000000001 RDI: 0000000000000000
[   65.028691] RBP: ffff88007b907d38 R08: 0000000000016f60 R09: 0000000000000000
[   65.029990] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
[   65.031295] R13: 0000000000000050 R14: 0000000000000000 R15: 0000000000000001
[   65.032527] FS:  0000000000000000(0000) GS:ffff88007f600000(0000) knlGS:0000000000000000
[   65.033981] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   65.035177] CR2: 0000000000000030 CR3: 000000007b27f000 CR4: 00000000000407f0
[   65.036568] Stack:
[   65.037011]  0000000000000000 0000000000000001 ffff88007b907d90 ffff88007a880220
[   65.038472]  ffff88007b768de8 ffff88007b907d48 ffffffffa037e4a5 ffff88007b907d80
[   65.039935]  ffffffffa036a6c8 ffff880037020e40 ffff88007a880000 ffff880037020e40
[   65.041468] Call Trace:
[   65.042050]  [<ffffffffa037e4a5>] nfs4_close_state+0x15/0x20 [nfsv4]
[   65.043209]  [<ffffffffa036a6c8>] nfs4_open_recover_helper+0x148/0x1f0 [nfsv4]
[   65.044529]  [<ffffffffa036a886>] nfs4_open_recover+0x116/0x150 [nfsv4]
[   65.045730]  [<ffffffffa036d98d>] nfs4_open_reclaim+0xad/0x150 [nfsv4]
[   65.046905]  [<ffffffffa037d979>] nfs4_do_reclaim+0x149/0x5f0 [nfsv4]
[   65.048071]  [<ffffffffa037e1dc>] nfs4_run_state_manager+0x3bc/0x670 [nfsv4]
[   65.049436]  [<ffffffffa037de20>] ? nfs4_do_reclaim+0x5f0/0x5f0 [nfsv4]
[   65.050686]  [<ffffffffa037de20>] ? nfs4_do_reclaim+0x5f0/0x5f0 [nfsv4]
[   65.051943]  [<ffffffff81088640>] kthread+0xc0/0xd0
[   65.052831]  [<ffffffff81088580>] ? insert_kthread_work+0x40/0x40
[   65.054697]  [<ffffffff8165686c>] ret_from_fork+0x7c/0xb0
[   65.056396]  [<ffffffff81088580>] ? insert_kthread_work+0x40/0x40
[   65.058208] Code: 5c 41 5d 5d c3 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48 89 e5 41 57 41 89 f7 41 56 41 89 ce 41 55 41 89 d5 41 54 53 48 89 fb <4c> 8b 67 30 f0 41 ff 44 24 44 49 8d 7c 24 40 e8 0e 0a 2d e1 44
[   65.065225] RIP  [<ffffffffa037d6ee>] __nfs4_close+0x1e/0x160 [nfsv4]
[   65.067175]  RSP <ffff88007b907d10>
[   65.068570] CR2: 0000000000000030
[   65.070098] ---[ end trace 0d1fe4f5c7dd6f8b ]---

Cc: <[email protected]> #3.7+
Signed-off-by: Weston Andros Adamson <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
I've seen a fair number of issues with kswapd and other processes
appearing to get stuck in v3.12-rc.  Using sysrq-p many times seems to
indicate that it gets stuck somewhere in list_lru_walk_node(), called
from prune_icache_sb() and super_cache_scan().

I never seem to be able to trigger a calltrace for functions above that
point.

So I decided to add the following to super_cache_scan():

    @@ -81,10 +81,14 @@ static unsigned long super_cache_scan(struct shrinker *shrink,
            inodes = list_lru_count_node(&sb->s_inode_lru, sc->nid);
            dentries = list_lru_count_node(&sb->s_dentry_lru, sc->nid);
            total_objects = dentries + inodes + fs_objects + 1;
    +printk("%s:%u: %s: dentries %lu inodes %lu total %lu\n", current->comm, current->pid, __func__, dentries, inodes, total_objects);

            /* proportion the scan between the caches */
            dentries = mult_frac(sc->nr_to_scan, dentries, total_objects);
            inodes = mult_frac(sc->nr_to_scan, inodes, total_objects);
    +printk("%s:%u: %s: dentries %lu inodes %lu\n", current->comm, current->pid, __func__, dentries, inodes);
    +BUG_ON(dentries == 0);
    +BUG_ON(inodes == 0);

            /*
             * prune the dcache first as the icache is pinned by it, then
    @@ -99,7 +103,7 @@ static unsigned long super_cache_scan(struct shrinker *shrink,
                    freed += sb->s_op->free_cached_objects(sb, fs_objects,
                                                           sc->nid);
            }
    -
    +printk("%s:%u: %s: dentries %lu inodes %lu freed %lu\n", current->comm, current->pid, __func__, dentries, inodes, freed);
            drop_super(sb);
            return freed;
     }

and shortly thereafter, having applied some pressure, I got this:

    update-apt-xapi:1616: super_cache_scan: dentries 25632 inodes 2 total 25635
    update-apt-xapi:1616: super_cache_scan: dentries 1023 inodes 0
    ------------[ cut here ]------------
    Kernel BUG at c0101994 [verbose debug info unavailable]
    Internal error: Oops - BUG: 0 [#3] SMP ARM
    Modules linked in: fuse rfcomm bnep bluetooth hid_cypress
    CPU: 0 PID: 1616 Comm: update-apt-xapi Tainted: G      D      3.12.0-rc7+ torvalds#154
    task: daea1200 ti: c3bf8000 task.ti: c3bf8000
    PC is at super_cache_scan+0x1c0/0x278
    LR is at trace_hardirqs_on+0x14/0x18
    Process update-apt-xapi (pid: 1616, stack limit = 0xc3bf8240)
    ...
    Backtrace:
      (super_cache_scan) from [<c00cd69c>] (shrink_slab+0x254/0x4c8)
      (shrink_slab) from [<c00d09a0>] (try_to_free_pages+0x3a0/0x5e0)
      (try_to_free_pages) from [<c00c59cc>] (__alloc_pages_nodemask+0x5)
      (__alloc_pages_nodemask) from [<c00e07c0>] (__pte_alloc+0x2c/0x13)
      (__pte_alloc) from [<c00e3a70>] (handle_mm_fault+0x84c/0x914)
      (handle_mm_fault) from [<c001a4cc>] (do_page_fault+0x1f0/0x3bc)
      (do_page_fault) from [<c001a7b0>] (do_translation_fault+0xac/0xb8)
      (do_translation_fault) from [<c000840c>] (do_DataAbort+0x38/0xa0)
      (do_DataAbort) from [<c00133f8>] (__dabt_usr+0x38/0x40)

Notice that we had a very low number of inodes, which were reduced to
zero my mult_frac().

Now, prune_icache_sb() calls list_lru_walk_node() passing that number of
inodes (0) into that as the number of objects to scan:

    long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
                         int nid)
    {
            LIST_HEAD(freeable);
            long freed;

            freed = list_lru_walk_node(&sb->s_inode_lru, nid, inode_lru_isolate,
                                           &freeable, &nr_to_scan);

which does:

    unsigned long
    list_lru_walk_node(struct list_lru *lru, int nid, list_lru_walk_cb isolate,
                       void *cb_arg, unsigned long *nr_to_walk)
    {

            struct list_lru_node    *nlru = &lru->node[nid];
            struct list_head *item, *n;
            unsigned long isolated = 0;

            spin_lock(&nlru->lock);
    restart:
            list_for_each_safe(item, n, &nlru->list) {
                    enum lru_status ret;

                    /*
                     * decrement nr_to_walk first so that we don't livelock if we
                     * get stuck on large numbesr of LRU_RETRY items
                     */
                    if (--(*nr_to_walk) == 0)
                            break;

So, if *nr_to_walk was zero when this function was entered, that means
we're wanting to operate on (~0UL)+1 objects - which might as well be
infinite.

Clearly this is not correct behaviour.  If we think about the behaviour
of this function when *nr_to_walk is 1, then clearly it's wrong - we
decrement first and then test for zero - which results in us doing
nothing at all.  A post-decrement would give the desired behaviour -
we'd try to walk one object and one object only if *nr_to_walk were one.

It also gives the correct behaviour for zero - we exit at this point.

Fixes: 5cedf72 ("list_lru: fix broken LRU_RETRY behaviour")
Signed-off-by: Russell King <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andrew Morton <[email protected]>
[ Modified to make sure we never underflow the count: this function gets
  called in a loop, so the 0 -> ~0ul transition is dangerous  - Linus ]
Signed-off-by: Linus Torvalds <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
A vmalloc fault needs to sync up PGD/PTE entry from init_mm to current
task's "active_mm".  ARC vmalloc fault handler however was using mm.

A vmalloc fault for non user task context (actually pre-userland, from
init thread's open for /dev/console) caused the handler to deref NULL mm
(for mm->pgd)

The reasons it worked so far is amazing:

1. By default (!SMP), vmalloc fault handler uses a cached value of PGD.
   In SMP that MMU register is repurposed hence need for mm pointer deref.

2. In pre-3.12 SMP kernel, the problem triggering vmalloc didn't exist in
   pre-userland code path - it was introduced with commit 20bafb3
   "n_tty: Move buffers into n_tty_data"

Signed-off-by: Vineet Gupta <[email protected]>
Cc: Gilad Ben-Yossef <[email protected]>
Cc: Noam Camus <[email protected]>
Cc: [email protected]    #3.10 and 3.11
Cc: Peter Hurley <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
With Line length being constant now, we can fold the 2 helpers into 1.
This allows applying any optimizations (forthcoming) to single place.

Signed-off-by: Vineet Gupta <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
…/kernel/git/vgupta/arc

Pull ARC changes from Vineet Gupta:
 - Towards a working SMP setup (ASID allocation, TLB Flush,...)
 - Support for TRACE_IRQFLAGS, LOCKDEP
 - cacheflush backend consolidation for I/D
 - Lots of allmodconfig fixlets from Chen
 - Other improvements/fixes

* tag 'arc-v3.13-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (25 commits)
  ARC: [plat-arcfpga] defconfig update
  smp, ARC: kill SMP single function call interrupt
  ARC: [SMP] Disallow RTSC
  ARC: [SMP] Fix build failures for large NR_CPUS
  ARC: [SMP] enlarge possible NR_CPUS
  ARC: [SMP] TLB flush
  ARC: [SMP] ASID allocation
  arc: export symbol for pm_power_off in reset.c
  arc: export symbol for save_stack_trace() in stacktrace.c
  arc: remove '__init' for get_hw_config_num_irq()
  arc: remove '__init' for first_lines_of_secondary()
  arc: remove '__init' for setup_processor() and arc_init_IRQ()
  arc: kgdb: add default implementation for kgdb_roundup_cpus()
  ARC: Fix bogus gcc warning and micro-optimise TLB iteration loop
  ARC: Add support for irqflags tracing and lockdep
  ARC: Reset the value of Interrupt Priority Register
  ARC: Reduce #ifdef'ery for unaligned access emulation
  ARC: Change calling convention of do_page_fault()
  ARC: cacheflush optim - PTAG can be loop invariant if V-P is const
  ARC: cacheflush refactor #3: Unify the {d,i}cache flush leaf helpers
  ...
mitake pushed a commit that referenced this issue Jan 12, 2014
…ux/kernel/git/tip/tip

Pull x86 boot changes from Ingo Molnar:
 "Two changes that prettify and compactify the SMP bootup output from:

     smpboot: Booting Node   0, Processors  #1 #2 #3 OK
     smpboot: Booting Node   1, Processors  #4 #5 torvalds#6 torvalds#7 OK
     smpboot: Booting Node   2, Processors  torvalds#8 torvalds#9 torvalds#10 torvalds#11 OK
     smpboot: Booting Node   3, Processors  torvalds#12 torvalds#13 torvalds#14 torvalds#15 OK
     Brought up 16 CPUs

  to something like:

     x86: Booting SMP configuration:
     .... node  #0, CPUs:        #1  #2  #3
     .... node  #1, CPUs:    #4  #5  torvalds#6  torvalds#7
     .... node  #2, CPUs:    torvalds#8  torvalds#9 torvalds#10 torvalds#11
     .... node  #3, CPUs:   torvalds#12 torvalds#13 torvalds#14 torvalds#15
     x86: Booted up 4 nodes, 16 CPUs"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Further compress CPUs bootup message
  x86: Improve the printout of the SMP bootup CPU table
mitake pushed a commit that referenced this issue Jan 12, 2014
This patch fixes a bug in delayed Task Aborted Status (TAS) handling,
where transport_send_task_abort() was not returning for the case
when the se_tfo->write_pending() callback indicated that last fabric
specific WRITE PDU had not yet been received.

It also adds an explicit cmd->scsi_status = SAM_STAT_TASK_ABORTED
assignment within transport_check_aborted_status() to avoid the case
where se_tfo->queue_status() is called when the SAM_STAT_TASK_ABORTED
assignment + ->queue_status() in transport_send_task_abort() does not
occur once SCF_SENT_DELAYED_TAS has been set.

Cc: <[email protected]> #3.2+
Signed-off-by: Nicholas Bellinger <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
Hayes Wang says:

====================
r8152 bug fixes

For the patch #3, I add netif_tx_lock() before checking the
netif_queue_stopped(). Besides, I add checking the skb queue
length before waking the tx queue.
====================

Signed-off-by: David S. Miller <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
extract_param() is called with max_length set to the total size of the
output buffer.  It's not safe to allow a parameter length equal to the
buffer size as the terminating null would be written one byte past the
end of the output buffer.

Signed-off-by: Eric Seppanen <[email protected]>
Cc: <[email protected]> #3.1+
Signed-off-by: Nicholas Bellinger <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
In iSCSI negotiations with initiator CHAP enabled, usernames with
trailing garbage are permitted, because the string comparison only
checks the strlen of the configured username.

e.g. "usernameXXXXX" will be permitted to match "username".

Just check one more byte so the trailing null char is also matched.

Signed-off-by: Eric Seppanen <[email protected]>
Cc: <[email protected]> #3.1+
Signed-off-by: Nicholas Bellinger <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
The following two commits implemented mmap support in the regular file
path and merged bin file support into the regular path.

 73d9714 ("sysfs: copy bin mmap support from fs/sysfs/bin.c to fs/sysfs/file.c")
 3124eb1 ("sysfs: merge regular and bin file handling")

After the merge, the following commands trigger a spurious lockdep
warning.  "test-mmap-read" simply mmaps the file and dumps the
content.

  $ cat /sys/block/sda/trace/act_mask
  $ test-mmap-read /sys/devices/pci0000\:00/0000\:00\:03.0/resource0 4096

  ======================================================
  [ INFO: possible circular locking dependency detected ]
  3.12.0-work+ torvalds#378 Not tainted
  -------------------------------------------------------
  test-mmap-read/567 is trying to acquire lock:
   (&of->mutex){+.+.+.}, at: [<ffffffff8120a8df>] sysfs_bin_mmap+0x4f/0x120

  but task is already holding lock:
   (&mm->mmap_sem){++++++}, at: [<ffffffff8114b399>] vm_mmap_pgoff+0x49/0xa0

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #3 (&mm->mmap_sem){++++++}:
  ...
  -> #2 (sr_mutex){+.+.+.}:
  ...
  -> #1 (&bdev->bd_mutex){+.+.+.}:
  ...
  -> #0 (&of->mutex){+.+.+.}:
  ...

  other info that might help us debug this:

  Chain exists of:
   &of->mutex --> sr_mutex --> &mm->mmap_sem

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(&mm->mmap_sem);
				 lock(sr_mutex);
				 lock(&mm->mmap_sem);
    lock(&of->mutex);

   *** DEADLOCK ***

  1 lock held by test-mmap-read/567:
   #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8114b399>] vm_mmap_pgoff+0x49/0xa0

  stack backtrace:
  CPU: 3 PID: 567 Comm: test-mmap-read Not tainted 3.12.0-work+ torvalds#378
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
   ffffffff81ed41a0 ffff880009441bc8 ffffffff81611ad2 ffffffff81eccb80
   ffff880009441c08 ffffffff8160f215 ffff880009441c60 ffff880009c75208
   0000000000000000 ffff880009c751e0 ffff880009c75208 ffff880009c74ac0
  Call Trace:
   [<ffffffff81611ad2>] dump_stack+0x4e/0x7a
   [<ffffffff8160f215>] print_circular_bug+0x2b0/0x2bf
   [<ffffffff8109ca0a>] __lock_acquire+0x1a3a/0x1e60
   [<ffffffff8109d6ba>] lock_acquire+0x9a/0x1d0
   [<ffffffff81615547>] mutex_lock_nested+0x67/0x3f0
   [<ffffffff8120a8df>] sysfs_bin_mmap+0x4f/0x120
   [<ffffffff8115d363>] mmap_region+0x3b3/0x5b0
   [<ffffffff8115d8ae>] do_mmap_pgoff+0x34e/0x3d0
   [<ffffffff8114b3ba>] vm_mmap_pgoff+0x6a/0xa0
   [<ffffffff8115be3e>] SyS_mmap_pgoff+0xbe/0x250
   [<ffffffff81008282>] SyS_mmap+0x22/0x30
   [<ffffffff8161a4d2>] system_call_fastpath+0x16/0x1b

This happens because one file nests sr_mutex, which nests mm->mmap_sem
under it, under of->mutex while mmap implementation naturally nests
of->mutex under mm->mmap_sem.  The warning is false positive as
of->mutex is per open-file and the two paths belong to two different
files.  This warning didn't trigger before regular and bin file
supports were merged because only bin file supported mmap and the
other side of locking happened only on regular files which used
equivalent but separate locking.

It'd be best if we give separate locking classes per file but we can't
easily do that.  Let's differentiate on ->mmap() for now.  Later we'll
add explicit file operations struct and can add per-ops lockdep key
there.

Signed-off-by: Tejun Heo <[email protected]>
Reported-by: Dave Jones <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
When booting Nokia N900 smartphone with v3.12 + omap2plus_defconfig
(LOCKDEP enabled) and CONFIG_DISPLAY_PANEL_SONY_ACX565AKM enabled,
the following BUG is seen during the boot:

[    7.302154] =====================================
[    7.307128] [ BUG: bad unlock balance detected! ]
[    7.312103] 3.12.0-los.git-2093492-00120-g5e01dc7 #3 Not tainted
[    7.318450] -------------------------------------
[    7.323425] kworker/u2:1/12 is trying to release lock (&ddata->mutex) at:
[    7.330657] [<c031b760>] acx565akm_enable+0x12c/0x18c
[    7.335998] but there are no more locks to release!

Fix by removing double unlock and handling the locking completely inside
acx565akm_panel_power_on() when doing the power on.

Reported-by: Eduardo Valentin <[email protected]>
Signed-off-by: Aaro Koskinen <[email protected]>
Cc: [email protected]
Signed-off-by: Tomi Valkeinen <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
With some devices, transfer hangs during I2C frame transmission. This issue
disappears when reducing the internal frequency of the TWI IP. Even if it is
indicated that internal clock max frequency is 66MHz, it seems we have
oversampling on I2C signals making TWI believe that a transfer in progress
is done.

This fix has no impact on the I2C bus frequency.

Cc: <[email protected]> #3.10+
Signed-off-by: Ludovic Desroches <[email protected]>
Acked-by: Wolfram Sang <[email protected]>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <[email protected]>
Signed-off-by: Nicolas Ferre <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
This patch changes special case handling for ISCSI_OP_SCSI_CMD
where an initiator sends a zero length Expected Data Transfer
Length (EDTL), but still sets the WRITE and/or READ flag bits
when no payload transfer is requested.

Many, many moons ago two special cases where added for an ancient
version of ESX that has long since been fixed, so instead of adding
a new special case for the reported bug with a Broadcom 57800 NIC,
go ahead and always strip off the incorrect WRITE + READ flag bits.

Also, avoid sending a reject here, as RFC-3720 does mandate this
case be handled without protocol error.

Reported-by: Witold Bazakbal <[email protected]>
Tested-by: Witold Bazakbal <[email protected]>
Cc: <[email protected]> #3.1+
Signed-off-by: Nicholas Bellinger <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun <[email protected]>
Cc: <[email protected]> #3.10+
Signed-off-by: Nicholas Bellinger <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
This patch fixes two cases in qla_target.c code where the
schedule_delayed_work() value was being incorrectly calculated
from sess->expires - jiffies.

Signed-off-by: Shivaram U <[email protected]>
Cc: <[email protected]> #3.6+
Signed-off-by: Nicholas Bellinger <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
The Allwinner A20 uses the ARM GIC as its internal interrupts controller. The
GIC can work on several interrupt triggers, and the A20 was actually setting it
up to use a rising edge as a trigger, while it was actually a level high
trigger, leading to some interrupts that would be completely ignored if the
edge was missed.

Signed-off-by: Maxime Ripard <[email protected]>
Acked-by: Hans de Goede <[email protected]>
Cc: [email protected] #3.12+
Signed-off-by: Olof Johansson <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
When shutting down a target there is a race condition between
iscsit_del_np() and __iscsi_target_login_thread().
The latter sets the thread pointer to NULL, and the former
tries to issue kthread_stop() on that pointer without any
synchronization.

This patch moves the np->np_thread NULL assignment into
iscsit_del_np(), after kthread_stop() has completed. It also
removes the signal_pending() + np_state check, and only
exits when kthread_should_stop() is true.

Reported-by: Hannes Reinecke <[email protected]>
Cc: <[email protected]> #3.12+
Signed-off-by: Nicholas Bellinger <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
This patch moves INIT_WORK setup for cq_desc->cq_[rx,tx]_work into
isert_create_device_ib_res(), instead of being done each callback
invocation in isert_cq_[rx,tx]_callback().

This also fixes a 'INFO: trying to register non-static key' warning
when cancel_work_sync() is called before INIT_WORK has setup the
struct work_struct.

Reported-by: Or Gerlitz <[email protected]>
Cc: <[email protected]> #3.12+
Signed-off-by: Nicholas Bellinger <[email protected]>
mitake pushed a commit that referenced this issue Jan 12, 2014
This patch allows FILEIO to update hw_max_sectors based on the current
max_bytes_per_io.  This is required because vfs_[writev,readv]() can accept
a maximum of 2048 iovecs per call, so the enforced hw_max_sectors really
needs to be calculated based on block_size.

This addresses a >= v3.5 bug where block_size=512 was rejecting > 1M
sized I/O requests, because FD_MAX_SECTORS was hardcoded to 2048 for
the block_size=4096 case.

(v2: Use max_bytes_per_io instead of ->update_hw_max_sectors)

Reported-by: Henrik Goldman <[email protected]>
Cc: <[email protected]> #3.5+
Signed-off-by: Nicholas Bellinger <[email protected]>
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