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Mali-400 r3p2#12

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mdrjr merged 3 commits intohardkernel:odroid-3.0.yfrom
rzk:odroid-3.0.y
Jan 16, 2013
Merged

Mali-400 r3p2#12
mdrjr merged 3 commits intohardkernel:odroid-3.0.yfrom
rzk:odroid-3.0.y

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@rzk rzk commented Jan 16, 2013

This pull req. introduces Mali-400 r3p2 support for exynos4412.
Old r2p4 is still here, selection is done using two CONFIGs, odroidx2_ubuntu_defconfig already updated for r3p2 usage.

Screenshots of r3p2 running on ubuntu:
http://imgur.com/a/f9pio es2gears glmark2
http://imgur.com/a/keaPD XBMC Eden

Stuff still missing:

  1. update for other _ubuntu defconfigs
  2. testing of r2p4 on android, I dont have r2p4 setup with android.
  3. GET_SECURE_ID_BUF1 and GET_SECURE_ID_BUF2 ioctls (we use Xorg drivers that dont use these, but in future we could benefit from them).

@ghost ghost assigned mdrjr Jan 16, 2013
mdrjr added a commit that referenced this pull request Jan 16, 2013
mali-400 r3p2 from rz2k ;) 

We now have r3p2 and r2p4 drivers on Kernel.

r3p2 is for Linux and r2p4 is for Android.

We should probably upgrade Android blobs as well.
@mdrjr mdrjr merged commit acc9bca into hardkernel:odroid-3.0.y Jan 16, 2013
hardkernel pushed a commit that referenced this pull request Mar 5, 2013
…d reasons

commit 5cf02d0 upstream.

We've had some reports of a deadlock where rpciod ends up with a stack
trace like this:

    PID: 2507   TASK: ffff88103691ab40  CPU: 14  COMMAND: "rpciod/14"
     #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9
     #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs]
     #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f
     #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8
     #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs]
     #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs]
     #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670
     #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271
     #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638
     #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f
    #10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e
    #11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f
    #12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad
    #13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942
    #14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a
    #15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9
    #16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b
    #17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808
    #18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c
    #19 [ffff8810343bfce8] inet_create at ffffffff81483ba6
    #20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7
    #21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc]
    #22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc]
    #23 [ffff8810343bfe38] worker_thread at ffffffff810887d0
    #24 [ffff8810343bfee8] kthread at ffffffff8108dd96
    #25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca

rpciod is trying to allocate memory for a new socket to talk to the
server. The VM ends up calling ->releasepage to get more memory, and it
tries to do a blocking commit. That commit can't succeed however without
a connected socket, so we deadlock.

Fix this by setting PF_FSTRANS on the workqueue task prior to doing the
socket allocation, and having nfs_release_page check for that flag when
deciding whether to do a commit call. Also, set PF_FSTRANS
unconditionally in rpc_async_schedule since that function can also do
allocations sometimes.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mdrjr pushed a commit that referenced this pull request Mar 27, 2013
[ Upstream commit 9cb6cb7 ]

The following script will produce a kernel oops:

    sudo ip netns add v
    sudo ip netns exec v ip ad add 127.0.0.1/8 dev lo
    sudo ip netns exec v ip link set lo up
    sudo ip netns exec v ip ro add 224.0.0.0/4 dev lo
    sudo ip netns exec v ip li add vxlan0 type vxlan id 42 group 239.1.1.1 dev lo
    sudo ip netns exec v ip link set vxlan0 up
    sudo ip netns del v

where inspect by gdb:

    Program received signal SIGSEGV, Segmentation fault.
    [Switching to Thread 107]
    0xffffffffa0289e33 in ?? ()
    (gdb) bt
    #0  vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
    #1  vxlan_stop (dev=0xffff88001bafa000) at drivers/net/vxlan.c:1087
    #2  0xffffffff812cc498 in __dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1299
    #3  0xffffffff812cd920 in dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1335
    #4  0xffffffff812cef31 in rollback_registered_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:4851
    #5  0xffffffff812cf040 in unregister_netdevice_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:5752
    #6  0xffffffff812cf1ba in default_device_exit_batch (net_list=0xffff88001f2e7e18) at net/core/dev.c:6170
    #7  0xffffffff812cab27 in cleanup_net (work=<optimized out>) at net/core/net_namespace.c:302
    #8  0xffffffff810540ef in process_one_work (worker=0xffff88001ba9ed40, work=0xffffffff8167d020) at kernel/workqueue.c:2157
    #9  0xffffffff810549d0 in worker_thread (__worker=__worker@entry=0xffff88001ba9ed40) at kernel/workqueue.c:2276
    #10 0xffffffff8105870c in kthread (_create=0xffff88001f2e5d68) at kernel/kthread.c:168
    #11 <signal handler called>
    #12 0x0000000000000000 in ?? ()
    #13 0x0000000000000000 in ?? ()
    (gdb) fr 0
    #0  vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
    533		struct sock *sk = vn->sock->sk;
    (gdb) l
    528	static int vxlan_leave_group(struct net_device *dev)
    529	{
    530		struct vxlan_dev *vxlan = netdev_priv(dev);
    531		struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
    532		int err = 0;
    533		struct sock *sk = vn->sock->sk;
    534		struct ip_mreqn mreq = {
    535			.imr_multiaddr.s_addr	= vxlan->gaddr,
    536			.imr_ifindex		= vxlan->link,
    537		};
    (gdb) p vn->sock
    $4 = (struct socket *) 0x0

The kernel calls `vxlan_exit_net` when deleting the netns before shutting down
vxlan interfaces. Later the removal of all vxlan interfaces, where `vn->sock`
is already gone causes the oops. so we should manually shutdown all interfaces
before deleting `vn->sock` as the patch does.

Signed-off-by: Zang MingJie <zealot0630@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hardkernel pushed a commit that referenced this pull request Jun 12, 2013
This patch fixes warnings due to missing lock on write error path.

  WARNING: at fs/hpfs/hpfs_fn.h:353 hpfs_truncate+0x75/0x80 [hpfs]()
  Hardware name: empty
  Pid: 26563, comm: dd Tainted: P           O 3.9.4 #12
  Call Trace:
    hpfs_truncate+0x75/0x80 [hpfs]
    hpfs_write_begin+0x84/0x90 [hpfs]
    _hpfs_bmap+0x10/0x10 [hpfs]
    generic_file_buffered_write+0x121/0x2c0
    __generic_file_aio_write+0x1c7/0x3f0
    generic_file_aio_write+0x7c/0x100
    do_sync_write+0x98/0xd0
    hpfs_file_write+0xd/0x50 [hpfs]
    vfs_write+0xa2/0x160
    sys_write+0x51/0xa0
    page_fault+0x22/0x30
    system_call_fastpath+0x1a/0x1f

Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: stable@kernel.org  # 2.6.39+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mdrjr pushed a commit that referenced this pull request Jun 22, 2013
commit bbd465d upstream.

This patch fixes warnings due to missing lock on write error path.

  WARNING: at fs/hpfs/hpfs_fn.h:353 hpfs_truncate+0x75/0x80 [hpfs]()
  Hardware name: empty
  Pid: 26563, comm: dd Tainted: P           O 3.9.4 #12
  Call Trace:
    hpfs_truncate+0x75/0x80 [hpfs]
    hpfs_write_begin+0x84/0x90 [hpfs]
    _hpfs_bmap+0x10/0x10 [hpfs]
    generic_file_buffered_write+0x121/0x2c0
    __generic_file_aio_write+0x1c7/0x3f0
    generic_file_aio_write+0x7c/0x100
    do_sync_write+0x98/0xd0
    hpfs_file_write+0xd/0x50 [hpfs]
    vfs_write+0xa2/0x160
    sys_write+0x51/0xa0
    page_fault+0x22/0x30
    system_call_fastpath+0x1a/0x1f

Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
hardkernel pushed a commit that referenced this pull request Jun 29, 2013
…d reasons

commit 5cf02d0 upstream.

We've had some reports of a deadlock where rpciod ends up with a stack
trace like this:

    PID: 2507   TASK: ffff88103691ab40  CPU: 14  COMMAND: "rpciod/14"
     #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9
     #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs]
     #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f
     #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8
     #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs]
     #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs]
     #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670
     #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271
     #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638
     #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f
    #10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e
    #11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f
    #12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad
    #13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942
    #14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a
    #15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9
    #16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b
    #17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808
    #18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c
    #19 [ffff8810343bfce8] inet_create at ffffffff81483ba6
    #20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7
    #21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc]
    #22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc]
    #23 [ffff8810343bfe38] worker_thread at ffffffff810887d0
    #24 [ffff8810343bfee8] kthread at ffffffff8108dd96
    #25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca

rpciod is trying to allocate memory for a new socket to talk to the
server. The VM ends up calling ->releasepage to get more memory, and it
tries to do a blocking commit. That commit can't succeed however without
a connected socket, so we deadlock.

Fix this by setting PF_FSTRANS on the workqueue task prior to doing the
socket allocation, and having nfs_release_page check for that flag when
deciding whether to do a commit call. Also, set PF_FSTRANS
unconditionally in rpc_async_schedule since that function can also do
allocations sometimes.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hardkernel pushed a commit that referenced this pull request Jul 3, 2013
If a too small MTU value is set with ioctl(HCISETACLMTU) or by a bogus
controller, memory corruption happens due to a memcpy() call with
negative length.

Fix this crash on either incoming or outgoing connections with a MTU
smaller than L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE:

[   46.885433] BUG: unable to handle kernel paging request at f56ad000
[   46.888037] IP: [<c03d94cd>] memcpy+0x1d/0x40
[   46.888037] *pdpt = 0000000000ac3001 *pde = 00000000373f8067 *pte = 80000000356ad060
[   46.888037] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC
[   46.888037] Modules linked in: hci_vhci bluetooth virtio_balloon i2c_piix4 uhci_hcd usbcore usb_common
[   46.888037] CPU: 0 PID: 1044 Comm: kworker/u3:0 Not tainted 3.10.0-rc1+ #12
[   46.888037] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[   46.888037] Workqueue: hci0 hci_rx_work [bluetooth]
[   46.888037] task: f59b15b0 ti: f55c4000 task.ti: f55c4000
[   46.888037] EIP: 0060:[<c03d94cd>] EFLAGS: 00010212 CPU: 0
[   46.888037] EIP is at memcpy+0x1d/0x40
[   46.888037] EAX: f56ac1c0 EBX: fffffff8 ECX: 3ffffc6e EDX: f55c5cf2
[   46.888037] ESI: f55c6b32 EDI: f56ad000 EBP: f55c5c68 ESP: f55c5c5c
[   46.888037]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[   46.888037] CR0: 8005003b CR2: f56ad000 CR3: 3557d000 CR4: 000006f0
[   46.888037] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[   46.888037] DR6: ffff0ff0 DR7: 00000400
[   46.888037] Stack:
[   46.888037]  fffffff8 00000010 00000003 f55c5cac f8c6a54c ffffffff f8c69eb2 00000000
[   46.888037]  f4783cdc f57f0070 f759c590 1001c580 00000003 0200000a 00000000 f5a88560
[   46.888037]  f5ba2600 f5a88560 00000041 00000000 f55c5d90 f8c6f4c7 00000008 f55c5cf2
[   46.888037] Call Trace:
[   46.888037]  [<f8c6a54c>] l2cap_send_cmd+0x1cc/0x230 [bluetooth]
[   46.888037]  [<f8c69eb2>] ? l2cap_global_chan_by_psm+0x152/0x1a0 [bluetooth]
[   46.888037]  [<f8c6f4c7>] l2cap_connect+0x3f7/0x540 [bluetooth]
[   46.888037]  [<c019b37b>] ? trace_hardirqs_off+0xb/0x10
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064ad20>] ? mutex_lock_nested+0x280/0x360
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<c064ad08>] ? mutex_lock_nested+0x268/0x360
[   46.888037]  [<c01a125b>] ? trace_hardirqs_on+0xb/0x10
[   46.888037]  [<f8c72f8d>] l2cap_recv_frame+0xb2d/0x1d30 [bluetooth]
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<f8c754f1>] l2cap_recv_acldata+0x2a1/0x320 [bluetooth]
[   46.888037]  [<f8c491d8>] hci_rx_work+0x518/0x810 [bluetooth]
[   46.888037]  [<f8c48df2>] ? hci_rx_work+0x132/0x810 [bluetooth]
[   46.888037]  [<c0158979>] process_one_work+0x1a9/0x600
[   46.888037]  [<c01588fb>] ? process_one_work+0x12b/0x600
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c0159187>] worker_thread+0xf7/0x320
[   46.888037]  [<c0159090>] ? rescuer_thread+0x290/0x290
[   46.888037]  [<c01602f8>] kthread+0xa8/0xb0
[   46.888037]  [<c0656777>] ret_from_kernel_thread+0x1b/0x28
[   46.888037]  [<c0160250>] ? flush_kthread_worker+0x120/0x120
[   46.888037] Code: c3 90 8d 74 26 00 e8 63 fc ff ff eb e8 90 55 89 e5 83 ec 0c 89 5d f4 89 75 f8 89 7d fc 3e 8d 74 26 00 89 cb 89 c7 c1 e9 02 89 d6 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 8b 5d f4 8b 75 f8 8b 7d fc 89
[   46.888037] EIP: [<c03d94cd>] memcpy+0x1d/0x40 SS:ESP 0068:f55c5c5c
[   46.888037] CR2: 00000000f56ad000
[   46.888037] ---[ end trace 0217c1f4d78714a9 ]---

Signed-off-by: Anderson Lizardo <anderson.lizardo@openbossa.org>
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
mdrjr pushed a commit that referenced this pull request Jul 7, 2013
commit 300b962 upstream.

If a too small MTU value is set with ioctl(HCISETACLMTU) or by a bogus
controller, memory corruption happens due to a memcpy() call with
negative length.

Fix this crash on either incoming or outgoing connections with a MTU
smaller than L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE:

[   46.885433] BUG: unable to handle kernel paging request at f56ad000
[   46.888037] IP: [<c03d94cd>] memcpy+0x1d/0x40
[   46.888037] *pdpt = 0000000000ac3001 *pde = 00000000373f8067 *pte = 80000000356ad060
[   46.888037] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC
[   46.888037] Modules linked in: hci_vhci bluetooth virtio_balloon i2c_piix4 uhci_hcd usbcore usb_common
[   46.888037] CPU: 0 PID: 1044 Comm: kworker/u3:0 Not tainted 3.10.0-rc1+ #12
[   46.888037] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[   46.888037] Workqueue: hci0 hci_rx_work [bluetooth]
[   46.888037] task: f59b15b0 ti: f55c4000 task.ti: f55c4000
[   46.888037] EIP: 0060:[<c03d94cd>] EFLAGS: 00010212 CPU: 0
[   46.888037] EIP is at memcpy+0x1d/0x40
[   46.888037] EAX: f56ac1c0 EBX: fffffff8 ECX: 3ffffc6e EDX: f55c5cf2
[   46.888037] ESI: f55c6b32 EDI: f56ad000 EBP: f55c5c68 ESP: f55c5c5c
[   46.888037]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[   46.888037] CR0: 8005003b CR2: f56ad000 CR3: 3557d000 CR4: 000006f0
[   46.888037] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[   46.888037] DR6: ffff0ff0 DR7: 00000400
[   46.888037] Stack:
[   46.888037]  fffffff8 00000010 00000003 f55c5cac f8c6a54c ffffffff f8c69eb2 00000000
[   46.888037]  f4783cdc f57f0070 f759c590 1001c580 00000003 0200000a 00000000 f5a88560
[   46.888037]  f5ba2600 f5a88560 00000041 00000000 f55c5d90 f8c6f4c7 00000008 f55c5cf2
[   46.888037] Call Trace:
[   46.888037]  [<f8c6a54c>] l2cap_send_cmd+0x1cc/0x230 [bluetooth]
[   46.888037]  [<f8c69eb2>] ? l2cap_global_chan_by_psm+0x152/0x1a0 [bluetooth]
[   46.888037]  [<f8c6f4c7>] l2cap_connect+0x3f7/0x540 [bluetooth]
[   46.888037]  [<c019b37b>] ? trace_hardirqs_off+0xb/0x10
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064ad20>] ? mutex_lock_nested+0x280/0x360
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<c064ad08>] ? mutex_lock_nested+0x268/0x360
[   46.888037]  [<c01a125b>] ? trace_hardirqs_on+0xb/0x10
[   46.888037]  [<f8c72f8d>] l2cap_recv_frame+0xb2d/0x1d30 [bluetooth]
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<f8c754f1>] l2cap_recv_acldata+0x2a1/0x320 [bluetooth]
[   46.888037]  [<f8c491d8>] hci_rx_work+0x518/0x810 [bluetooth]
[   46.888037]  [<f8c48df2>] ? hci_rx_work+0x132/0x810 [bluetooth]
[   46.888037]  [<c0158979>] process_one_work+0x1a9/0x600
[   46.888037]  [<c01588fb>] ? process_one_work+0x12b/0x600
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c0159187>] worker_thread+0xf7/0x320
[   46.888037]  [<c0159090>] ? rescuer_thread+0x290/0x290
[   46.888037]  [<c01602f8>] kthread+0xa8/0xb0
[   46.888037]  [<c0656777>] ret_from_kernel_thread+0x1b/0x28
[   46.888037]  [<c0160250>] ? flush_kthread_worker+0x120/0x120
[   46.888037] Code: c3 90 8d 74 26 00 e8 63 fc ff ff eb e8 90 55 89 e5 83 ec 0c 89 5d f4 89 75 f8 89 7d fc 3e 8d 74 26 00 89 cb 89 c7 c1 e9 02 89 d6 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 8b 5d f4 8b 75 f8 8b 7d fc 89
[   46.888037] EIP: [<c03d94cd>] memcpy+0x1d/0x40 SS:ESP 0068:f55c5c5c
[   46.888037] CR2: 00000000f56ad000
[   46.888037] ---[ end trace 0217c1f4d78714a9 ]---

Signed-off-by: Anderson Lizardo <anderson.lizardo@openbossa.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
ruppi pushed a commit that referenced this pull request Jul 16, 2013
Several people reported the warning: "kernel BUG at kernel/timer.c:729!"
and the stack trace is:

	#7 [ffff880214d25c10] mod_timer+501 at ffffffff8106d905
	#8 [ffff880214d25c50] br_multicast_del_pg.isra.20+261 at ffffffffa0731d25 [bridge]
	#9 [ffff880214d25c80] br_multicast_disable_port+88 at ffffffffa0732948 [bridge]
	#10 [ffff880214d25cb0] br_stp_disable_port+154 at ffffffffa072bcca [bridge]
	#11 [ffff880214d25ce8] br_device_event+520 at ffffffffa072a4e8 [bridge]
	#12 [ffff880214d25d18] notifier_call_chain+76 at ffffffff8164aafc
	#13 [ffff880214d25d50] raw_notifier_call_chain+22 at ffffffff810858f6
	#14 [ffff880214d25d60] call_netdevice_notifiers+45 at ffffffff81536aad
	#15 [ffff880214d25d80] dev_close_many+183 at ffffffff81536d17
	#16 [ffff880214d25dc0] rollback_registered_many+168 at ffffffff81537f68
	#17 [ffff880214d25de8] rollback_registered+49 at ffffffff81538101
	#18 [ffff880214d25e10] unregister_netdevice_queue+72 at ffffffff815390d8
	#19 [ffff880214d25e30] __tun_detach+272 at ffffffffa074c2f0 [tun]
	#20 [ffff880214d25e88] tun_chr_close+45 at ffffffffa074c4bd [tun]
	#21 [ffff880214d25ea8] __fput+225 at ffffffff8119b1f1
	#22 [ffff880214d25ef0] ____fput+14 at ffffffff8119b3fe
	#23 [ffff880214d25f00] task_work_run+159 at ffffffff8107cf7f
	#24 [ffff880214d25f30] do_notify_resume+97 at ffffffff810139e1
	#25 [ffff880214d25f50] int_signal+18 at ffffffff8164f292

this is due to I forgot to check if mp->timer is armed in
br_multicast_del_pg(). This bug is introduced by
commit 9f00b2e (bridge: only expire the mdb entry
when query is received).

Same for __br_mdb_del().

Tested-by: poma <pomidorabelisima@gmail.com>
Reported-by: LiYonghua <809674045@qq.com>
Reported-by: Robert Hancock <hancockrwd@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ruppi pushed a commit that referenced this pull request Jul 20, 2013
commit 300b962 upstream.

If a too small MTU value is set with ioctl(HCISETACLMTU) or by a bogus
controller, memory corruption happens due to a memcpy() call with
negative length.

Fix this crash on either incoming or outgoing connections with a MTU
smaller than L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE:

[   46.885433] BUG: unable to handle kernel paging request at f56ad000
[   46.888037] IP: [<c03d94cd>] memcpy+0x1d/0x40
[   46.888037] *pdpt = 0000000000ac3001 *pde = 00000000373f8067 *pte = 80000000356ad060
[   46.888037] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC
[   46.888037] Modules linked in: hci_vhci bluetooth virtio_balloon i2c_piix4 uhci_hcd usbcore usb_common
[   46.888037] CPU: 0 PID: 1044 Comm: kworker/u3:0 Not tainted 3.10.0-rc1+ #12
[   46.888037] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[   46.888037] Workqueue: hci0 hci_rx_work [bluetooth]
[   46.888037] task: f59b15b0 ti: f55c4000 task.ti: f55c4000
[   46.888037] EIP: 0060:[<c03d94cd>] EFLAGS: 00010212 CPU: 0
[   46.888037] EIP is at memcpy+0x1d/0x40
[   46.888037] EAX: f56ac1c0 EBX: fffffff8 ECX: 3ffffc6e EDX: f55c5cf2
[   46.888037] ESI: f55c6b32 EDI: f56ad000 EBP: f55c5c68 ESP: f55c5c5c
[   46.888037]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[   46.888037] CR0: 8005003b CR2: f56ad000 CR3: 3557d000 CR4: 000006f0
[   46.888037] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[   46.888037] DR6: ffff0ff0 DR7: 00000400
[   46.888037] Stack:
[   46.888037]  fffffff8 00000010 00000003 f55c5cac f8c6a54c ffffffff f8c69eb2 00000000
[   46.888037]  f4783cdc f57f0070 f759c590 1001c580 00000003 0200000a 00000000 f5a88560
[   46.888037]  f5ba2600 f5a88560 00000041 00000000 f55c5d90 f8c6f4c7 00000008 f55c5cf2
[   46.888037] Call Trace:
[   46.888037]  [<f8c6a54c>] l2cap_send_cmd+0x1cc/0x230 [bluetooth]
[   46.888037]  [<f8c69eb2>] ? l2cap_global_chan_by_psm+0x152/0x1a0 [bluetooth]
[   46.888037]  [<f8c6f4c7>] l2cap_connect+0x3f7/0x540 [bluetooth]
[   46.888037]  [<c019b37b>] ? trace_hardirqs_off+0xb/0x10
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064ad20>] ? mutex_lock_nested+0x280/0x360
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<c064ad08>] ? mutex_lock_nested+0x268/0x360
[   46.888037]  [<c01a125b>] ? trace_hardirqs_on+0xb/0x10
[   46.888037]  [<f8c72f8d>] l2cap_recv_frame+0xb2d/0x1d30 [bluetooth]
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<f8c754f1>] l2cap_recv_acldata+0x2a1/0x320 [bluetooth]
[   46.888037]  [<f8c491d8>] hci_rx_work+0x518/0x810 [bluetooth]
[   46.888037]  [<f8c48df2>] ? hci_rx_work+0x132/0x810 [bluetooth]
[   46.888037]  [<c0158979>] process_one_work+0x1a9/0x600
[   46.888037]  [<c01588fb>] ? process_one_work+0x12b/0x600
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c0159187>] worker_thread+0xf7/0x320
[   46.888037]  [<c0159090>] ? rescuer_thread+0x290/0x290
[   46.888037]  [<c01602f8>] kthread+0xa8/0xb0
[   46.888037]  [<c0656777>] ret_from_kernel_thread+0x1b/0x28
[   46.888037]  [<c0160250>] ? flush_kthread_worker+0x120/0x120
[   46.888037] Code: c3 90 8d 74 26 00 e8 63 fc ff ff eb e8 90 55 89 e5 83 ec 0c 89 5d f4 89 75 f8 89 7d fc 3e 8d 74 26 00 89 cb 89 c7 c1 e9 02 89 d6 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 8b 5d f4 8b 75 f8 8b 7d fc 89
[   46.888037] EIP: [<c03d94cd>] memcpy+0x1d/0x40 SS:ESP 0068:f55c5c5c
[   46.888037] CR2: 00000000f56ad000
[   46.888037] ---[ end trace 0217c1f4d78714a9 ]---

Signed-off-by: Anderson Lizardo <anderson.lizardo@openbossa.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hardkernel pushed a commit that referenced this pull request Jul 22, 2013
When we try to open a file with O_TMPFILE flag, we will trigger a bug.
The root cause is that in ext4_orphan_add() we check ->i_nlink == 0 and
this check always fails because we set ->i_nlink = 1 in
inode_init_always().  We can use the following program to trigger it:

int main(int argc, char *argv[])
{
	int fd;

	fd = open(argv[1], O_TMPFILE, 0666);
	if (fd < 0) {
		perror("open ");
		return -1;
	}
	close(fd);
	return 0;
}

The oops message looks like this:

kernel BUG at fs/ext4/namei.c:2572!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: dlci bridge stp hidp cmtp kernelcapi l2tp_ppp l2tp_netlink l2tp_core sctp libcrc32c rfcomm tun fuse nfnetli
nk can_raw ipt_ULOG can_bcm x25 scsi_transport_iscsi ipx p8023 p8022 appletalk phonet psnap vmw_vsock_vmci_transport af_key vmw_vmci rose vsock atm can netrom ax25 af_rxrpc ir
da pppoe pppox ppp_generic slhc bluetooth nfc rfkill rds caif_socket caif crc_ccitt af_802154 llc2 llc snd_hda_codec_realtek snd_hda_intel snd_hda_codec serio_raw snd_pcm pcsp
kr edac_core snd_page_alloc snd_timer snd soundcore r8169 mii sr_mod cdrom pata_atiixp radeon backlight drm_kms_helper ttm
CPU: 1 PID: 1812571 Comm: trinity-child2 Not tainted 3.11.0-rc1+ #12
Hardware name: Gigabyte Technology Co., Ltd. GA-MA78GM-S2H/GA-MA78GM-S2H, BIOS F12a 04/23/2010
task: ffff88007dfe69a0 ti: ffff88010f7b6000 task.ti: ffff88010f7b6000
RIP: 0010:[<ffffffff8125ce69>]  [<ffffffff8125ce69>] ext4_orphan_add+0x299/0x2b0
RSP: 0018:ffff88010f7b7cf8  EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff8800966d3020 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88007dfe70b8 RDI: 0000000000000001
RBP: ffff88010f7b7d40 R08: ffff880126a3c4e0 R09: ffff88010f7b7ca0
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801271fd668
R13: ffff8800966d2f78 R14: ffff88011d7089f0 R15: ffff88007dfe69a0
FS:  00007f70441a3740(0000) GS:ffff88012a800000(0000) knlGS:00000000f77c96c0
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002834000 CR3: 0000000107964000 CR4: 00000000000007e0
DR0: 0000000000780000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Stack:
 0000000000002000 00000020810b6dde 0000000000000000 ffff88011d46db00
 ffff8800966d3020 ffff88011d7089f0 ffff88009c7f4c10 ffff88010f7b7f2c
 ffff88007dfe69a0 ffff88010f7b7da8 ffffffff8125cfac ffff880100000004
Call Trace:
 [<ffffffff8125cfac>] ext4_tmpfile+0x12c/0x180
 [<ffffffff811cba78>] path_openat+0x238/0x700
 [<ffffffff8100afc4>] ? native_sched_clock+0x24/0x80
 [<ffffffff811cc647>] do_filp_open+0x47/0xa0
 [<ffffffff811db73f>] ? __alloc_fd+0xaf/0x200
 [<ffffffff811ba2e4>] do_sys_open+0x124/0x210
 [<ffffffff81010725>] ? syscall_trace_enter+0x25/0x290
 [<ffffffff811ba3ee>] SyS_open+0x1e/0x20
 [<ffffffff816ca8d4>] tracesys+0xdd/0xe2
 [<ffffffff81001001>] ? start_thread_common.constprop.6+0x1/0xa0
Code: 04 00 00 00 89 04 24 31 c0 e8 c4 77 04 00 e9 43 fe ff ff 66 25 00 d0 66 3d 00 80 0f 84 0e fe ff ff 83 7b 48 00 0f 84 04 fe ff ff <0f> 0b 49 8b 8c 24 50 07 00 00 e9 88 fe ff ff 0f 1f 84 00 00 00

Here we couldn't call clear_nlink() directly because in d_tmpfile() we
will call inode_dec_link_count() to decrease ->i_nlink.  So this commit
tries to call d_tmpfile() before ext4_orphan_add() to fix this problem.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Tested-by: Darrick J. Wong <darrick.wong@oracle.com>
Tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
hardkernel pushed a commit that referenced this pull request Jul 30, 2013
…s struct file

The following call chain:
------------------------------------------------------------
nfs4_get_vfs_file
- nfsd_open
  - dentry_open
    - do_dentry_open
      - __get_file_write_access
        - get_write_access
          - return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
------------------------------------------------------------

can result in the following state:
------------------------------------------------------------
struct nfs4_file {
...
  fi_fds = {0xffff880c1fa65c80, 0xffffffffffffffe6, 0x0},
  fi_access = {{
      counter = 0x1
    }, {
      counter = 0x0
    }},
...
------------------------------------------------------------

1) First time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NULL, hence nfsd_open() is called where we get status set to an error
and fp->fi_fds[O_WRONLY] to -ETXTBSY. Thus we do not reach
nfs4_file_get_access() and fi_access[O_WRONLY] is not incremented.

2) Second time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NOT NULL (-ETXTBSY), so nfsd_open() is NOT called, but
nfs4_file_get_access() IS called and fi_access[O_WRONLY] is incremented.
Thus we leave a landmine in the form of the nfs4_file data structure in
an incorrect state.

3) Eventually, when __nfs4_file_put_access() is called it finds
fi_access[O_WRONLY] being non-zero, it decrements it and calls
nfs4_file_put_fd() which tries to fput -ETXTBSY.
------------------------------------------------------------
...
     [exception RIP: fput+0x9]
     RIP: ffffffff81177fa9  RSP: ffff88062e365c90  RFLAGS: 00010282
     RAX: ffff880c2b3d99cc  RBX: ffff880c2b3d9978  RCX: 0000000000000002
     RDX: dead000000100101  RSI: 0000000000000001  RDI: ffffffffffffffe6
     RBP: ffff88062e365c90   R8: ffff88041fe797d8   R9: ffff88062e365d58
     R10: 0000000000000008  R11: 0000000000000000  R12: 0000000000000001
     R13: 0000000000000007  R14: 0000000000000000  R15: 0000000000000000
     ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
  #9 [ffff88062e365c98] __nfs4_file_put_access at ffffffffa0562334 [nfsd]
 #10 [ffff88062e365cc8] nfs4_file_put_access at ffffffffa05623ab [nfsd]
 #11 [ffff88062e365ce8] free_generic_stateid at ffffffffa056634d [nfsd]
 #12 [ffff88062e365d18] release_open_stateid at ffffffffa0566e4b [nfsd]
 #13 [ffff88062e365d38] nfsd4_close at ffffffffa0567401 [nfsd]
 #14 [ffff88062e365d88] nfsd4_proc_compound at ffffffffa0557f28 [nfsd]
 #15 [ffff88062e365dd8] nfsd_dispatch at ffffffffa054543e [nfsd]
 #16 [ffff88062e365e18] svc_process_common at ffffffffa04ba5a4 [sunrpc]
 #17 [ffff88062e365e98] svc_process at ffffffffa04babe0 [sunrpc]
 #18 [ffff88062e365eb8] nfsd at ffffffffa0545b62 [nfsd]
 #19 [ffff88062e365ee8] kthread at ffffffff81090886
 #20 [ffff88062e365f48] kernel_thread at ffffffff8100c14a
------------------------------------------------------------

Cc: stable@vger.kernel.org
Signed-off-by: Harshula Jayasuriya <harshula@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
hardkernel pushed a commit that referenced this pull request Aug 5, 2013
[  198.720048] ------------[ cut here ]------------
[  198.720108] WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:255 dev_watchdog+0x229/0x240()
[  198.720118] NETDEV WATCHDOG: eth0 (sis900): transmit queue 0 timed out
[  198.720125] Modules linked in: bridge stp llc dmfe sundance 3c59x sis900 mii
[  198.720159] CPU: 0 PID: 0 Comm: swapper Not tainted 3.11.0-rc3+ #12
[  198.720167] Hardware name: System Manufacturer System Name/TUSI-M, BIOS ASUS TUSI-M ACPI BIOS
Revision 1013 Beta 001 12/14/2001
[  198.720175]  000000ff c13fa6b9 c169ddcc c12208d6 c169ddf8 c1031e4d c1664a84 c169de24
[  198.720197]  00000000 c165f5ea 000000ff c13fa6b9 00000001 000000ff c1664a84 c169de10
[  198.720217]  c1031f13 00000009 c169de08 c1664a84 c169de24 c169de50 c13fa6b9 c165f5ea
[  198.720240] Call Trace:
[  198.720257]  [<c13fa6b9>] ? dev_watchdog+0x229/0x240
[  198.720274]  [<c12208d6>] dump_stack+0x16/0x20
[  198.720306]  [<c1031e4d>] warn_slowpath_common+0x7d/0xa0
[  198.720318]  [<c13fa6b9>] ? dev_watchdog+0x229/0x240
[  198.720330]  [<c1031f13>] warn_slowpath_fmt+0x33/0x40
[  198.720342]  [<c13fa6b9>] dev_watchdog+0x229/0x240
[  198.720357]  [<c103f158>] call_timer_fn+0x78/0x150
[  198.720369]  [<c103f0e0>] ? internal_add_timer+0x40/0x40
[  198.720381]  [<c13fa490>] ? dev_init_scheduler+0xa0/0xa0
[  198.720392]  [<c103f33f>] run_timer_softirq+0x10f/0x200
[  198.720412]  [<c103954f>] ? __do_softirq+0x6f/0x210
[  198.720424]  [<c13fa490>] ? dev_init_scheduler+0xa0/0xa0
[  198.720435]  [<c1039598>] __do_softirq+0xb8/0x210
[  198.720467]  [<c14b54d2>] ? _raw_spin_unlock+0x22/0x30
[  198.720484]  [<c1003245>] ? handle_irq+0x25/0xd0
[  198.720496]  [<c1039c0c>] irq_exit+0x9c/0xb0
[  198.720508]  [<c14bc9d7>] do_IRQ+0x47/0x94
[  198.720534]  [<c1056078>] ? hrtimer_start+0x28/0x30
[  198.720564]  [<c14bc8b1>] common_interrupt+0x31/0x38
[  198.720589]  [<c1008692>] ? default_idle+0x22/0xa0
[  198.720600]  [<c10083c7>] arch_cpu_idle+0x17/0x30
[  198.720631]  [<c106d23d>] cpu_startup_entry+0xcd/0x180
[  198.720643]  [<c14ae30a>] rest_init+0xaa/0xb0
[  198.720654]  [<c14ae260>] ? reciprocal_value+0x50/0x50
[  198.720668]  [<c17044e0>] ? repair_env_string+0x60/0x60
[  198.720679]  [<c1704bda>] start_kernel+0x29a/0x350
[  198.720690]  [<c17044e0>] ? repair_env_string+0x60/0x60
[  198.720721]  [<c1704269>] i386_start_kernel+0x39/0xa0
[  198.720729] ---[ end trace 81e0a6266f5c73a8 ]---
[  198.720740] eth0: Transmit timeout, status 00000204 00000000

timer routine checks the link status and if it's up calls
netif_carrier_on() allowing upper layer to start the tx queue
even if the auto-negotiation process is not finished.

Also remove ugly auto-negotiation check from the sis900_start_xmit()

CC: Duan Fugang <B38611@freescale.com>
CC: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
mdrjr pushed a commit that referenced this pull request Aug 26, 2013
…s struct file

commit e4daf1f upstream.

The following call chain:
------------------------------------------------------------
nfs4_get_vfs_file
- nfsd_open
  - dentry_open
    - do_dentry_open
      - __get_file_write_access
        - get_write_access
          - return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
------------------------------------------------------------

can result in the following state:
------------------------------------------------------------
struct nfs4_file {
...
  fi_fds = {0xffff880c1fa65c80, 0xffffffffffffffe6, 0x0},
  fi_access = {{
      counter = 0x1
    }, {
      counter = 0x0
    }},
...
------------------------------------------------------------

1) First time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NULL, hence nfsd_open() is called where we get status set to an error
and fp->fi_fds[O_WRONLY] to -ETXTBSY. Thus we do not reach
nfs4_file_get_access() and fi_access[O_WRONLY] is not incremented.

2) Second time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NOT NULL (-ETXTBSY), so nfsd_open() is NOT called, but
nfs4_file_get_access() IS called and fi_access[O_WRONLY] is incremented.
Thus we leave a landmine in the form of the nfs4_file data structure in
an incorrect state.

3) Eventually, when __nfs4_file_put_access() is called it finds
fi_access[O_WRONLY] being non-zero, it decrements it and calls
nfs4_file_put_fd() which tries to fput -ETXTBSY.
------------------------------------------------------------
...
     [exception RIP: fput+0x9]
     RIP: ffffffff81177fa9  RSP: ffff88062e365c90  RFLAGS: 00010282
     RAX: ffff880c2b3d99cc  RBX: ffff880c2b3d9978  RCX: 0000000000000002
     RDX: dead000000100101  RSI: 0000000000000001  RDI: ffffffffffffffe6
     RBP: ffff88062e365c90   R8: ffff88041fe797d8   R9: ffff88062e365d58
     R10: 0000000000000008  R11: 0000000000000000  R12: 0000000000000001
     R13: 0000000000000007  R14: 0000000000000000  R15: 0000000000000000
     ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
  #9 [ffff88062e365c98] __nfs4_file_put_access at ffffffffa0562334 [nfsd]
 #10 [ffff88062e365cc8] nfs4_file_put_access at ffffffffa05623ab [nfsd]
 #11 [ffff88062e365ce8] free_generic_stateid at ffffffffa056634d [nfsd]
 #12 [ffff88062e365d18] release_open_stateid at ffffffffa0566e4b [nfsd]
 #13 [ffff88062e365d38] nfsd4_close at ffffffffa0567401 [nfsd]
 #14 [ffff88062e365d88] nfsd4_proc_compound at ffffffffa0557f28 [nfsd]
 #15 [ffff88062e365dd8] nfsd_dispatch at ffffffffa054543e [nfsd]
 #16 [ffff88062e365e18] svc_process_common at ffffffffa04ba5a4 [sunrpc]
 #17 [ffff88062e365e98] svc_process at ffffffffa04babe0 [sunrpc]
 #18 [ffff88062e365eb8] nfsd at ffffffffa0545b62 [nfsd]
 #19 [ffff88062e365ee8] kthread at ffffffff81090886
 #20 [ffff88062e365f48] kernel_thread at ffffffff8100c14a
------------------------------------------------------------

Signed-off-by: Harshula Jayasuriya <harshula@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Gu1 pushed a commit to Gu1/linux that referenced this pull request Aug 30, 2013
…optimizations

Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.

For instance in the following function:

void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
	waiter->magic = waiter;
	INIT_LIST_HEAD(&waiter->list);
}

compiled as:

800554d0 <debug_mutex_lock_common>:
800554d0:       e92d4008        push    {r3, lr}
800554d4:       e1a00001        mov     r0, r1
800554d8:       e3a02010        mov     r2, hardkernel#16 ; 0x10
800554dc:       e3a01011        mov     r1, hardkernel#17 ; 0x11
800554e0:       eb04426e        bl      80165ea0 <memset>
800554e4:       e1a03000        mov     r3, r0
800554e8:       e583000c        str     r0, [r3, hardkernel#12]
800554ec:       e5830000        str     r0, [r3]
800554f:       e5830004        str     r0, [r3, hardkernel#4]
800554f4:       e8bd8008        pop     {r3, pc}

GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.

This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:

Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).

Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:

save r8:
-       str     lr, [sp, #-4]!
+       stmfd   sp!, {r8, lr}

and restore r8 on both exit paths:
-       ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+       ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
(...)
        tst     r2, hardkernel#16
        stmneia ip!, {r1, r3, r8, lr}
-       ldr     lr, [sp], hardkernel#4
+       ldmfd   sp!, {r8, lr}

Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:

save r8:
-       stmfd   sp!, {r4-r7, lr}
+       stmfd   sp!, {r4-r8, lr}

and restore r8 on both exit paths:
        bgt     3b
-       ldmeqfd sp!, {r4-r7, pc}
+       ldmeqfd sp!, {r4-r8, pc}
(...)
        tst     r2, hardkernel#16
        stmneia ip!, {r4-r7}
-       ldmfd   sp!, {r4-r7, lr}
+       ldmfd   sp!, {r4-r8, lr}

Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".

Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Gu1 pushed a commit to Gu1/linux that referenced this pull request Aug 30, 2013
The following script will produce a kernel oops:

    sudo ip netns add v
    sudo ip netns exec v ip ad add 127.0.0.1/8 dev lo
    sudo ip netns exec v ip link set lo up
    sudo ip netns exec v ip ro add 224.0.0.0/4 dev lo
    sudo ip netns exec v ip li add vxlan0 type vxlan id 42 group 239.1.1.1 dev lo
    sudo ip netns exec v ip link set vxlan0 up
    sudo ip netns del v

where inspect by gdb:

    Program received signal SIGSEGV, Segmentation fault.
    [Switching to Thread 107]
    0xffffffffa0289e33 in ?? ()
    (gdb) bt
    #0  vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
    hardkernel#1  vxlan_stop (dev=0xffff88001bafa000) at drivers/net/vxlan.c:1087
    hardkernel#2  0xffffffff812cc498 in __dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1299
    hardkernel#3  0xffffffff812cd920 in dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1335
    hardkernel#4  0xffffffff812cef31 in rollback_registered_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:4851
    hardkernel#5  0xffffffff812cf040 in unregister_netdevice_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:5752
    hardkernel#6  0xffffffff812cf1ba in default_device_exit_batch (net_list=0xffff88001f2e7e18) at net/core/dev.c:6170
    hardkernel#7  0xffffffff812cab27 in cleanup_net (work=<optimized out>) at net/core/net_namespace.c:302
    hardkernel#8  0xffffffff810540ef in process_one_work (worker=0xffff88001ba9ed40, work=0xffffffff8167d020) at kernel/workqueue.c:2157
    hardkernel#9  0xffffffff810549d0 in worker_thread (__worker=__worker@entry=0xffff88001ba9ed40) at kernel/workqueue.c:2276
    hardkernel#10 0xffffffff8105870c in kthread (_create=0xffff88001f2e5d68) at kernel/kthread.c:168
    hardkernel#11 <signal handler called>
    hardkernel#12 0x0000000000000000 in ?? ()
    hardkernel#13 0x0000000000000000 in ?? ()
    (gdb) fr 0
    #0  vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
    533		struct sock *sk = vn->sock->sk;
    (gdb) l
    528	static int vxlan_leave_group(struct net_device *dev)
    529	{
    530		struct vxlan_dev *vxlan = netdev_priv(dev);
    531		struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
    532		int err = 0;
    533		struct sock *sk = vn->sock->sk;
    534		struct ip_mreqn mreq = {
    535			.imr_multiaddr.s_addr	= vxlan->gaddr,
    536			.imr_ifindex		= vxlan->link,
    537		};
    (gdb) p vn->sock
    $4 = (struct socket *) 0x0

The kernel calls `vxlan_exit_net` when deleting the netns before shutting down
vxlan interfaces. Later the removal of all vxlan interfaces, where `vn->sock`
is already gone causes the oops. so we should manually shutdown all interfaces
before deleting `vn->sock` as the patch does.

Signed-off-by: Zang MingJie <zealot0630@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Gu1 pushed a commit to Gu1/linux that referenced this pull request Aug 30, 2013
…s struct file

commit e4daf1f upstream.

The following call chain:
------------------------------------------------------------
nfs4_get_vfs_file
- nfsd_open
  - dentry_open
    - do_dentry_open
      - __get_file_write_access
        - get_write_access
          - return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
------------------------------------------------------------

can result in the following state:
------------------------------------------------------------
struct nfs4_file {
...
  fi_fds = {0xffff880c1fa65c80, 0xffffffffffffffe6, 0x0},
  fi_access = {{
      counter = 0x1
    }, {
      counter = 0x0
    }},
...
------------------------------------------------------------

1) First time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NULL, hence nfsd_open() is called where we get status set to an error
and fp->fi_fds[O_WRONLY] to -ETXTBSY. Thus we do not reach
nfs4_file_get_access() and fi_access[O_WRONLY] is not incremented.

2) Second time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NOT NULL (-ETXTBSY), so nfsd_open() is NOT called, but
nfs4_file_get_access() IS called and fi_access[O_WRONLY] is incremented.
Thus we leave a landmine in the form of the nfs4_file data structure in
an incorrect state.

3) Eventually, when __nfs4_file_put_access() is called it finds
fi_access[O_WRONLY] being non-zero, it decrements it and calls
nfs4_file_put_fd() which tries to fput -ETXTBSY.
------------------------------------------------------------
...
     [exception RIP: fput+0x9]
     RIP: ffffffff81177fa9  RSP: ffff88062e365c90  RFLAGS: 00010282
     RAX: ffff880c2b3d99cc  RBX: ffff880c2b3d9978  RCX: 0000000000000002
     RDX: dead000000100101  RSI: 0000000000000001  RDI: ffffffffffffffe6
     RBP: ffff88062e365c90   R8: ffff88041fe797d8   R9: ffff88062e365d58
     R10: 0000000000000008  R11: 0000000000000000  R12: 0000000000000001
     R13: 0000000000000007  R14: 0000000000000000  R15: 0000000000000000
     ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
  hardkernel#9 [ffff88062e365c98] __nfs4_file_put_access at ffffffffa0562334 [nfsd]
 hardkernel#10 [ffff88062e365cc8] nfs4_file_put_access at ffffffffa05623ab [nfsd]
 hardkernel#11 [ffff88062e365ce8] free_generic_stateid at ffffffffa056634d [nfsd]
 hardkernel#12 [ffff88062e365d18] release_open_stateid at ffffffffa0566e4b [nfsd]
 hardkernel#13 [ffff88062e365d38] nfsd4_close at ffffffffa0567401 [nfsd]
 hardkernel#14 [ffff88062e365d88] nfsd4_proc_compound at ffffffffa0557f28 [nfsd]
 hardkernel#15 [ffff88062e365dd8] nfsd_dispatch at ffffffffa054543e [nfsd]
 hardkernel#16 [ffff88062e365e18] svc_process_common at ffffffffa04ba5a4 [sunrpc]
 hardkernel#17 [ffff88062e365e98] svc_process at ffffffffa04babe0 [sunrpc]
 hardkernel#18 [ffff88062e365eb8] nfsd at ffffffffa0545b62 [nfsd]
 hardkernel#19 [ffff88062e365ee8] kthread at ffffffff81090886
 hardkernel#20 [ffff88062e365f48] kernel_thread at ffffffff8100c14a
------------------------------------------------------------

Signed-off-by: Harshula Jayasuriya <harshula@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mdrjr pushed a commit that referenced this pull request Oct 6, 2013
…optimizations

Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.

For instance in the following function:

void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
	waiter->magic = waiter;
	INIT_LIST_HEAD(&waiter->list);
}

compiled as:

800554d0 <debug_mutex_lock_common>:
800554d0:       e92d4008        push    {r3, lr}
800554d4:       e1a00001        mov     r0, r1
800554d8:       e3a02010        mov     r2, #16 ; 0x10
800554dc:       e3a01011        mov     r1, #17 ; 0x11
800554e0:       eb04426e        bl      80165ea0 <memset>
800554e4:       e1a03000        mov     r3, r0
800554e8:       e583000c        str     r0, [r3, #12]
800554ec:       e5830000        str     r0, [r3]
800554f:       e5830004        str     r0, [r3, #4]
800554f4:       e8bd8008        pop     {r3, pc}

GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.

This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:

Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).

Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:

save r8:
-       str     lr, [sp, #-4]!
+       stmfd   sp!, {r8, lr}

and restore r8 on both exit paths:
-       ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+       ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
(...)
        tst     r2, #16
        stmneia ip!, {r1, r3, r8, lr}
-       ldr     lr, [sp], #4
+       ldmfd   sp!, {r8, lr}

Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:

save r8:
-       stmfd   sp!, {r4-r7, lr}
+       stmfd   sp!, {r4-r8, lr}

and restore r8 on both exit paths:
        bgt     3b
-       ldmeqfd sp!, {r4-r7, pc}
+       ldmeqfd sp!, {r4-r8, pc}
(...)
        tst     r2, #16
        stmneia ip!, {r4-r7}
-       ldmfd   sp!, {r4-r7, lr}
+       ldmfd   sp!, {r4-r8, lr}

Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".

Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
mdrjr pushed a commit that referenced this pull request Oct 25, 2013
…optimizations

Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.

For instance in the following function:

void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
	waiter->magic = waiter;
	INIT_LIST_HEAD(&waiter->list);
}

compiled as:

800554d0 <debug_mutex_lock_common>:
800554d0:       e92d4008        push    {r3, lr}
800554d4:       e1a00001        mov     r0, r1
800554d8:       e3a02010        mov     r2, #16 ; 0x10
800554dc:       e3a01011        mov     r1, #17 ; 0x11
800554e0:       eb04426e        bl      80165ea0 <memset>
800554e4:       e1a03000        mov     r3, r0
800554e8:       e583000c        str     r0, [r3, #12]
800554ec:       e5830000        str     r0, [r3]
800554f:       e5830004        str     r0, [r3, #4]
800554f4:       e8bd8008        pop     {r3, pc}

GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.

This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:

Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).

Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:

save r8:
-       str     lr, [sp, #-4]!
+       stmfd   sp!, {r8, lr}

and restore r8 on both exit paths:
-       ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+       ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
(...)
        tst     r2, #16
        stmneia ip!, {r1, r3, r8, lr}
-       ldr     lr, [sp], #4
+       ldmfd   sp!, {r8, lr}

Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:

save r8:
-       stmfd   sp!, {r4-r7, lr}
+       stmfd   sp!, {r4-r8, lr}

and restore r8 on both exit paths:
        bgt     3b
-       ldmeqfd sp!, {r4-r7, pc}
+       ldmeqfd sp!, {r4-r8, pc}
(...)
        tst     r2, #16
        stmneia ip!, {r4-r7}
-       ldmfd   sp!, {r4-r7, lr}
+       ldmfd   sp!, {r4-r8, lr}

Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".

Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
mdrjr pushed a commit that referenced this pull request Oct 29, 2013
commit 300b962 upstream.

If a too small MTU value is set with ioctl(HCISETACLMTU) or by a bogus
controller, memory corruption happens due to a memcpy() call with
negative length.

Fix this crash on either incoming or outgoing connections with a MTU
smaller than L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE:

[   46.885433] BUG: unable to handle kernel paging request at f56ad000
[   46.888037] IP: [<c03d94cd>] memcpy+0x1d/0x40
[   46.888037] *pdpt = 0000000000ac3001 *pde = 00000000373f8067 *pte = 80000000356ad060
[   46.888037] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC
[   46.888037] Modules linked in: hci_vhci bluetooth virtio_balloon i2c_piix4 uhci_hcd usbcore usb_common
[   46.888037] CPU: 0 PID: 1044 Comm: kworker/u3:0 Not tainted 3.10.0-rc1+ #12
[   46.888037] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[   46.888037] Workqueue: hci0 hci_rx_work [bluetooth]
[   46.888037] task: f59b15b0 ti: f55c4000 task.ti: f55c4000
[   46.888037] EIP: 0060:[<c03d94cd>] EFLAGS: 00010212 CPU: 0
[   46.888037] EIP is at memcpy+0x1d/0x40
[   46.888037] EAX: f56ac1c0 EBX: fffffff8 ECX: 3ffffc6e EDX: f55c5cf2
[   46.888037] ESI: f55c6b32 EDI: f56ad000 EBP: f55c5c68 ESP: f55c5c5c
[   46.888037]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[   46.888037] CR0: 8005003b CR2: f56ad000 CR3: 3557d000 CR4: 000006f0
[   46.888037] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[   46.888037] DR6: ffff0ff0 DR7: 00000400
[   46.888037] Stack:
[   46.888037]  fffffff8 00000010 00000003 f55c5cac f8c6a54c ffffffff f8c69eb2 00000000
[   46.888037]  f4783cdc f57f0070 f759c590 1001c580 00000003 0200000a 00000000 f5a88560
[   46.888037]  f5ba2600 f5a88560 00000041 00000000 f55c5d90 f8c6f4c7 00000008 f55c5cf2
[   46.888037] Call Trace:
[   46.888037]  [<f8c6a54c>] l2cap_send_cmd+0x1cc/0x230 [bluetooth]
[   46.888037]  [<f8c69eb2>] ? l2cap_global_chan_by_psm+0x152/0x1a0 [bluetooth]
[   46.888037]  [<f8c6f4c7>] l2cap_connect+0x3f7/0x540 [bluetooth]
[   46.888037]  [<c019b37b>] ? trace_hardirqs_off+0xb/0x10
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064ad20>] ? mutex_lock_nested+0x280/0x360
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<c064ad08>] ? mutex_lock_nested+0x268/0x360
[   46.888037]  [<c01a125b>] ? trace_hardirqs_on+0xb/0x10
[   46.888037]  [<f8c72f8d>] l2cap_recv_frame+0xb2d/0x1d30 [bluetooth]
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<f8c754f1>] l2cap_recv_acldata+0x2a1/0x320 [bluetooth]
[   46.888037]  [<f8c491d8>] hci_rx_work+0x518/0x810 [bluetooth]
[   46.888037]  [<f8c48df2>] ? hci_rx_work+0x132/0x810 [bluetooth]
[   46.888037]  [<c0158979>] process_one_work+0x1a9/0x600
[   46.888037]  [<c01588fb>] ? process_one_work+0x12b/0x600
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c0159187>] worker_thread+0xf7/0x320
[   46.888037]  [<c0159090>] ? rescuer_thread+0x290/0x290
[   46.888037]  [<c01602f8>] kthread+0xa8/0xb0
[   46.888037]  [<c0656777>] ret_from_kernel_thread+0x1b/0x28
[   46.888037]  [<c0160250>] ? flush_kthread_worker+0x120/0x120
[   46.888037] Code: c3 90 8d 74 26 00 e8 63 fc ff ff eb e8 90 55 89 e5 83 ec 0c 89 5d f4 89 75 f8 89 7d fc 3e 8d 74 26 00 89 cb 89 c7 c1 e9 02 89 d6 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 8b 5d f4 8b 75 f8 8b 7d fc 89
[   46.888037] EIP: [<c03d94cd>] memcpy+0x1d/0x40 SS:ESP 0068:f55c5c5c
[   46.888037] CR2: 00000000f56ad000
[   46.888037] ---[ end trace 0217c1f4d78714a9 ]---

Signed-off-by: Anderson Lizardo <anderson.lizardo@openbossa.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hardkernel pushed a commit that referenced this pull request Nov 8, 2013
When booting secondary CPUs, announce_cpu() is called to show which cpu has
been brought up. For example:

[    0.402751] smpboot: Booting Node   0, Processors  #1 #2 #3 #4 #5 OK
[    0.525667] smpboot: Booting Node   1, Processors  #6 #7 #8 #9 #10 #11 OK
[    0.755592] smpboot: Booting Node   0, Processors  #12 #13 #14 #15 #16 #17 OK
[    0.890495] smpboot: Booting Node   1, Processors  #18 #19 #20 #21 #22 #23

But the last "OK" is lost, because 'nr_cpu_ids-1' represents the maximum
possible cpu id. It should use the maximum present cpu id in case not all
CPUs booted up.

Signed-off-by: Libin <huawei.libin@huawei.com>
Cc: <guohanjun@huawei.com>
Cc: <wangyijing@huawei.com>
Cc: <fenghua.yu@intel.com>
Cc: <paul.gortmaker@windriver.com>
Link: http://lkml.kernel.org/r/1378378676-18276-1-git-send-email-huawei.libin@huawei.com
[ tweaked the changelog, removed unnecessary line break, tweaked the format to align the fields vertically. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hardkernel pushed a commit that referenced this pull request Nov 8, 2013
  Injecting memory failure for page 0x19d0 at 0xb77d2000
  MCE 0x19d0: non LRU page recovery: Ignored
  MCE: Software-unpoisoned page 0x19d0
  BUG: Bad page state in process bash  pfn:019d0
  page:f3461a00 count:0 mapcount:0 mapping:  (null) index:0x0
  page flags: 0x40000404(referenced|reserved)
  Modules linked in: nfsd auth_rpcgss i915 nfs_acl nfs lockd video drm_kms_helper drm bnep rfcomm sunrpc bluetooth psmouse parport_pc ppdev lp serio_raw fscache parport gpio_ich lpc_ich mac_hid i2c_algo_bit tpm_tis wmi usb_storage hid_generic usbhid hid e1000e firewire_ohci firewire_core ahci ptp libahci pps_core crc_itu_t
  CPU: 3 PID: 2123 Comm: bash Not tainted 3.11.0-rc6+ #12
  Hardware name: LENOVO 7034DD7/        , BIOS 9HKT47AUS 01//2012
   00000000 00000000 e9625ea c15ec49b f3461a00 e9625eb8 c15ea119 c17cbf18
   ef084314 000019d0 f3461a00 e9625ed8 c110dc8a f3461a00 00000001 00000000
   f3461a00 40000404 00000000 e9625ef8 c110dcc1 f3461a00 f3461a00 000019d0
  Call Trace:
    dump_stack+0x41/0x52
    bad_page+0xcf/0xeb
    free_pages_prepare+0x12a/0x140
    free_hot_cold_page+0x21/0x110
    __put_single_page+0x21/0x30
    put_page+0x25/0x40
    unpoison_memory+0x107/0x200
    hwpoison_unpoison+0x20/0x30
    simple_attr_write+0xb6/0xd0
    vfs_write+0xa0/0x1b0
    SyS_write+0x4f/0x90
    sysenter_do_call+0x12/0x22
  Disabling lock debugging due to kernel taint

Testcase:

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>

#define PAGES_TO_TEST 1
#define PAGE_SIZE	4096

int main(void)
{
	char *mem;

	mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
			PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);

	if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
		return -1;

	munmap(mem, PAGES_TO_TEST * PAGE_SIZE);

	return 0;
}

There is one page reference count for default empty zero page,
madvise_hwpoison add another one by get_user_pages_fast.  memory_hwpoison
reduce one page reference count since it's a non LRU page.
unpoison_memory release the last page reference count and free empty zero
page to buddy system which is not correct since empty zero page has
PG_reserved flag.  This patch fix it by don't reduce the page reference
count under 1 against empty zero page.

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hardkernel pushed a commit that referenced this pull request Nov 8, 2013
When parsing lines from objdump a line containing source code starting
with a numeric label is mistaken for a line of disassembly starting with
a memory address.

Current validation fails to recognise that the "memory address" is out
of range and calculates an invalid offset which later causes this
segfault:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000457315 in disasm__calc_percent (notes=0xc98970, evidx=0, offset=143705, end=2127526177, path=0x7fffffffbf50)
    at util/annotate.c:631
631				hits += h->addr[offset++];
(gdb) bt
 #0  0x0000000000457315 in disasm__calc_percent (notes=0xc98970, evidx=0, offset=143705, end=2127526177, path=0x7fffffffbf50)
    at util/annotate.c:631
 #1  0x00000000004d65e3 in annotate_browser__calc_percent (browser=0x7fffffffd130, evsel=0xa01da0) at ui/browsers/annotate.c:364
 #2  0x00000000004d7433 in annotate_browser__run (browser=0x7fffffffd130, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:672
 #3  0x00000000004d80c9 in symbol__tui_annotate (sym=0xc989a0, map=0xa02660, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:962
 #4  0x00000000004d7aa0 in hist_entry__tui_annotate (he=0xdf73f0, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:823
 #5  0x00000000004dd648 in perf_evsel__hists_browse (evsel=0xa01da0, nr_events=1, helpline=
    0x58b768 "For a higher level overview, try: perf report --sort comm,dso", ev_name=0xa02cd0 "cycles", left_exits=false, hbt=
    0x0, min_pcnt=0, env=0xa011e0) at ui/browsers/hists.c:1659
 #6  0x00000000004de372 in perf_evlist__tui_browse_hists (evlist=0xa01520, help=
    0x58b768 "For a higher level overview, try: perf report --sort comm,dso", hbt=0x0, min_pcnt=0, env=0xa011e0)
    at ui/browsers/hists.c:1950
 #7  0x000000000042cf6b in __cmd_report (rep=0x7fffffffd6c0) at builtin-report.c:581
 #8  0x000000000042e25d in cmd_report (argc=0, argv=0x7fffffffe4b0, prefix=0x0) at builtin-report.c:965
 #9  0x000000000041a0e1 in run_builtin (p=0x801548, argc=1, argv=0x7fffffffe4b0) at perf.c:319
 #10 0x000000000041a319 in handle_internal_command (argc=1, argv=0x7fffffffe4b0) at perf.c:376
 #11 0x000000000041a465 in run_argv (argcp=0x7fffffffe38c, argv=0x7fffffffe380) at perf.c:420
 #12 0x000000000041a707 in main (argc=1, argv=0x7fffffffe4b0) at perf.c:521

After the fix is applied the symbol can be annotated showing the
problematic line "1:      rep"

copy_user_generic_string  /usr/lib/debug/lib/modules/3.9.10-100.fc17.x86_64/vmlinux
             */
            ENTRY(copy_user_generic_string)
                    CFI_STARTPROC
                    ASM_STAC
                    andl %edx,%edx
              and    %edx,%edx
                    jz 4f
              je     37
                    cmpl $8,%edx
              cmp    $0x8,%edx
                    jb 2f           /* less than 8 bytes, go to byte copy loop */
              jb     33
                    ALIGN_DESTINATION
              mov    %edi,%ecx
              and    $0x7,%ecx
              je     28
              sub    $0x8,%ecx
              neg    %ecx
              sub    %ecx,%edx
        1a:   mov    (%rsi),%al
              mov    %al,(%rdi)
              inc    %rsi
              inc    %rdi
              dec    %ecx
              jne    1a
                    movl %edx,%ecx
        28:   mov    %edx,%ecx
                    shrl $3,%ecx
              shr    $0x3,%ecx
                    andl $7,%edx
              and    $0x7,%edx
            1:      rep
100.00        rep    movsq %ds:(%rsi),%es:(%rdi)
                    movsq
            2:      movl %edx,%ecx
        33:   mov    %edx,%ecx
            3:      rep
              rep    movsb %ds:(%rsi),%es:(%rdi)
                    movsb
            4:      xorl %eax,%eax
        37:   xor    %eax,%eax
              data32 xchg %ax,%ax
                    ASM_CLAC
                    ret
              retq

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1379009721-27667-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
ruppi pushed a commit that referenced this pull request Nov 17, 2013
As the new x86 CPU bootup printout format code maintainer, I am
taking immediate action to improve and clean (and thus indulge
my OCD) the reporting of the cores when coming up online.

Fix padding to a right-hand alignment, cleanup code and bind
reporting width to the max number of supported CPUs on the
system, like this:

 [    0.074509] smpboot: Booting Node   0, Processors:      #1  #2  #3  #4  #5  #6  #7 OK
 [    0.644008] smpboot: Booting Node   1, Processors:  #8  #9 #10 #11 #12 #13 #14 #15 OK
 [    1.245006] smpboot: Booting Node   2, Processors: #16 #17 #18 #19 #20 #21 #22 #23 OK
 [    1.864005] smpboot: Booting Node   3, Processors: #24 #25 #26 #27 #28 #29 #30 #31 OK
 [    2.489005] smpboot: Booting Node   4, Processors: #32 #33 #34 #35 #36 #37 #38 #39 OK
 [    3.093005] smpboot: Booting Node   5, Processors: #40 #41 #42 #43 #44 #45 #46 #47 OK
 [    3.698005] smpboot: Booting Node   6, Processors: #48 #49 #50 #51 #52 #53 #54 #55 OK
 [    4.304005] smpboot: Booting Node   7, Processors: #56 #57 #58 #59 #60 #61 #62 #63 OK
 [    4.961413] Brought up 64 CPUs

and this:

 [    0.072367] smpboot: Booting Node   0, Processors:    #1 #2 #3 #4 #5 #6 #7 OK
 [    0.686329] Brought up 8 CPUs

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Libin <huawei.libin@huawei.com>
Cc: wangyijing@huawei.com
Cc: fenghua.yu@intel.com
Cc: guohanjun@huawei.com
Cc: paul.gortmaker@windriver.com
Link: http://lkml.kernel.org/r/20130927143554.GF4422@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
ruppi pushed a commit that referenced this pull request Nov 17, 2013
Turn it into (for example):

[    0.073380] x86: Booting SMP configuration:
[    0.074005] .... node   #0, CPUs:          #1   #2   #3   #4   #5   #6   #7
[    0.603005] .... node   #1, CPUs:     #8   #9  #10  #11  #12  #13  #14  #15
[    1.200005] .... node   #2, CPUs:    #16  #17  #18  #19  #20  #21  #22  #23
[    1.796005] .... node   #3, CPUs:    #24  #25  #26  #27  #28  #29  #30  #31
[    2.393005] .... node   #4, CPUs:    #32  #33  #34  #35  #36  #37  #38  #39
[    2.996005] .... node   #5, CPUs:    #40  #41  #42  #43  #44  #45  #46  #47
[    3.600005] .... node   #6, CPUs:    #48  #49  #50  #51  #52  #53  #54  #55
[    4.202005] .... node   #7, CPUs:    #56  #57  #58  #59  #60  #61  #62  #63
[    4.811005] .... node   #8, CPUs:    #64  #65  #66  #67  #68  #69  #70  #71
[    5.421006] .... node   #9, CPUs:    #72  #73  #74  #75  #76  #77  #78  #79
[    6.032005] .... node  #10, CPUs:    #80  #81  #82  #83  #84  #85  #86  #87
[    6.648006] .... node  #11, CPUs:    #88  #89  #90  #91  #92  #93  #94  #95
[    7.262005] .... node  #12, CPUs:    #96  #97  #98  #99 #100 #101 #102 #103
[    7.865005] .... node  #13, CPUs:   #104 #105 #106 #107 #108 #109 #110 #111
[    8.466005] .... node  #14, CPUs:   #112 #113 #114 #115 #116 #117 #118 #119
[    9.073006] .... node  #15, CPUs:   #120 #121 #122 #123 #124 #125 #126 #127
[    9.679901] x86: Booted up 16 nodes, 128 CPUs

and drop useless elements.

Change num_digits() to hpa's division-avoiding, cell-phone-typed
version which he went at great lengths and pains to submit on a
Saturday evening.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: huawei.libin@huawei.com
Cc: wangyijing@huawei.com
Cc: fenghua.yu@intel.com
Cc: guohanjun@huawei.com
Cc: paul.gortmaker@windriver.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20130930095624.GB16383@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
ruppi pushed a commit to ruppi/linux that referenced this pull request Jan 7, 2014
…C (4.7.2) optimizations

Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.

For instance in the following function:

void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
	waiter->magic = waiter;
	INIT_LIST_HEAD(&waiter->list);
}

compiled as:

800554d0 <debug_mutex_lock_common>:
800554d0:       e92d4008        push    {r3, lr}
800554d4:       e1a00001        mov     r0, r1
800554d8:       e3a02010        mov     r2, hardkernel#16 ; 0x10
800554dc:       e3a01011        mov     r1, hardkernel#17 ; 0x11
800554e0:       eb04426e        bl      80165ea0 <memset>
800554e4:       e1a03000        mov     r3, r0
800554e8:       e583000c        str     r0, [r3, hardkernel#12]
800554ec:       e5830000        str     r0, [r3]
800554f:       e5830004        str     r0, [r3, hardkernel#4]
800554f4:       e8bd8008        pop     {r3, pc}

GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.

This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:

Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).

Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:

save r8:
-       str     lr, [sp, #-4]!
+       stmfd   sp!, {r8, lr}

and restore r8 on both exit paths:
-       ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+       ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
(...)
        tst     r2, hardkernel#16
        stmneia ip!, {r1, r3, r8, lr}
-       ldr     lr, [sp], hardkernel#4
+       ldmfd   sp!, {r8, lr}

Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:

save r8:
-       stmfd   sp!, {r4-r7, lr}
+       stmfd   sp!, {r4-r8, lr}

and restore r8 on both exit paths:
        bgt     3b
-       ldmeqfd sp!, {r4-r7, pc}
+       ldmeqfd sp!, {r4-r8, pc}
(...)
        tst     r2, hardkernel#16
        stmneia ip!, {r4-r7}
-       ldmfd   sp!, {r4-r7, lr}
+       ldmfd   sp!, {r4-r8, lr}

Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".

Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
(cherry picked from commit 455bd4c)

Change-Id: Idfbebdd48103e5fa4ae7faeae78dfabace28f0a7
Signed-off-by: Olof Johansson <olofj@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/47027
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/58754
Reviewed-by: Sonny Rao <sonnyrao@chromium.org>
Tested-by: Sonny Rao <sonnyrao@chromium.org>
Commit-Queue: Sonny Rao <sonnyrao@chromium.org>
hardkernel pushed a commit that referenced this pull request Jan 16, 2014
Function free_dmar_iommu() may access domain->iommu_lock by
	spin_unlock_irqrestore(&domain->iommu_lock, flags);
after freeing corresponding domain structure.

Sample stack dump:
[    8.912818] =========================
[    8.917072] [ BUG: held lock freed! ]
[    8.921335] 3.13.0-rc1-gerry+ #12 Not tainted
[    8.926375] -------------------------
[    8.930629] swapper/0/1 is freeing memory ffff880c23b56040-ffff880c23b5613f, with a lock still held there!
[    8.941675]  (&(&domain->iommu_lock)->rlock){......}, at: [<ffffffff81dc775c>] init_dmars+0x72c/0x95b
[    8.952582] 1 lock held by swapper/0/1:
[    8.957031]  #0:  (&(&domain->iommu_lock)->rlock){......}, at: [<ffffffff81dc775c>] init_dmars+0x72c/0x95b
[    8.968487]
[    8.968487] stack backtrace:
[    8.973602] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-rc1-gerry+ #12
[    8.981556] Hardware name: Intel Corporation LH Pass ........../SVRBD-ROW_T, BIOS SE5C600.86B.99.99.x059.091020121352 09/10/2012
[    8.994742]  ffff880c23b56040 ffff88042dd33c98 ffffffff815617fd ffff88042dd38b28
[    9.003566]  ffff88042dd33cd0 ffffffff810a977a ffff880c23b56040 0000000000000086
[    9.012403]  ffff88102c4923c0 ffff88042ddb4800 ffffffff81b1e8c0 ffff88042dd33d28
[    9.021240] Call Trace:
[    9.024138]  [<ffffffff815617fd>] dump_stack+0x4d/0x66
[    9.030057]  [<ffffffff810a977a>] debug_check_no_locks_freed+0x15a/0x160
[    9.037723]  [<ffffffff811aa1c2>] kmem_cache_free+0x62/0x5b0
[    9.044225]  [<ffffffff81465e27>] domain_exit+0x197/0x1c0
[    9.050418]  [<ffffffff81dc7788>] init_dmars+0x758/0x95b
[    9.056527]  [<ffffffff81dc7dfa>] intel_iommu_init+0x351/0x438
[    9.063207]  [<ffffffff81d8a711>] ? iommu_setup+0x27d/0x27d
[    9.069601]  [<ffffffff81d8a739>] pci_iommu_init+0x28/0x52
[    9.075910]  [<ffffffff81000342>] do_one_initcall+0x122/0x180
[    9.082509]  [<ffffffff81077738>] ? parse_args+0x1e8/0x320
[    9.088815]  [<ffffffff81d850e8>] kernel_init_freeable+0x1e1/0x26c
[    9.095895]  [<ffffffff81d84833>] ? do_early_param+0x88/0x88
[    9.102396]  [<ffffffff8154f580>] ? rest_init+0xd0/0xd0
[    9.108410]  [<ffffffff8154f58e>] kernel_init+0xe/0x130
[    9.114423]  [<ffffffff81574a2c>] ret_from_fork+0x7c/0xb0
[    9.120612]  [<ffffffff8154f580>] ? rest_init+0xd0/0xd0

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
hardkernel pushed a commit to ruppi/linux that referenced this pull request Apr 3, 2014
Commit 42f921a (cpufreq: remove sysfs files for CPUs which failed to
come back after resume) tried to do this but missed this piece of code
to fix.

Currently we are getting this on suspend/resume:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 877 at fs/sysfs/dir.c:52 sysfs_warn_dup+0x68/0x84()
sysfs: cannot create duplicate filename '/devices/system/cpu/cpu1/cpufreq'
Modules linked in: brcmfmac brcmutil
CPU: 0 PID: 877 Comm: test-rtc-resume Not tainted 3.14.0-rc2-00259-g9398a10cd964 hardkernel#12
[<c0015bac>] (unwind_backtrace) from [<c0011850>] (show_stack+0x10/0x14)
[<c0011850>] (show_stack) from [<c056e018>] (dump_stack+0x80/0xcc)
[<c056e018>] (dump_stack) from [<c0025e44>] (warn_slowpath_common+0x64/0x88)
[<c0025e44>] (warn_slowpath_common) from [<c0025efc>] (warn_slowpath_fmt+0x30/0x40)
[<c0025efc>] (warn_slowpath_fmt) from [<c012776c>] (sysfs_warn_dup+0x68/0x84)
[<c012776c>] (sysfs_warn_dup) from [<c0127a54>] (sysfs_do_create_link_sd+0xb0/0xb8)
[<c0127a54>] (sysfs_do_create_link_sd) from [<c038ef64>] (__cpufreq_add_dev.isra.27+0x2a8/0x814)
[<c038ef64>] (__cpufreq_add_dev.isra.27) from [<c038f548>] (cpufreq_cpu_callback+0x70/0x8c)
[<c038f548>] (cpufreq_cpu_callback) from [<c0043864>] (notifier_call_chain+0x44/0x84)
[<c0043864>] (notifier_call_chain) from [<c0025f60>] (__cpu_notify+0x28/0x44)
[<c0025f60>] (__cpu_notify) from [<c00261e8>] (_cpu_up+0xf0/0x140)
[<c00261e8>] (_cpu_up) from [<c0569eb8>] (enable_nonboot_cpus+0x68/0xb0)
[<c0569eb8>] (enable_nonboot_cpus) from [<c006339c>] (suspend_devices_and_enter+0x198/0x2dc)
[<c006339c>] (suspend_devices_and_enter) from [<c0063654>] (pm_suspend+0x174/0x1e8)
[<c0063654>] (pm_suspend) from [<c00624e0>] (state_store+0x6c/0xbc)
[<c00624e0>] (state_store) from [<c01fc200>] (kobj_attr_store+0x14/0x20)
[<c01fc200>] (kobj_attr_store) from [<c0126e50>] (sysfs_kf_write+0x44/0x48)
[<c0126e50>] (sysfs_kf_write) from [<c012a274>] (kernfs_fop_write+0xb4/0x14c)
[<c012a274>] (kernfs_fop_write) from [<c00d4818>] (vfs_write+0xa8/0x180)
[<c00d4818>] (vfs_write) from [<c00d4bb8>] (SyS_write+0x3c/0x70)
[<c00d4bb8>] (SyS_write) from [<c000e620>] (ret_fast_syscall+0x0/0x30)
---[ end trace 76969904b614c18f ]---

Fix this by removing sysfs link for cpufreq directory when cpu removed
isn't policy->cpu.

Revamps: 42f921a (cpufreq: remove sysfs files for CPUs which failed to come back after resume)
Reported-and-tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
mdrjr pushed a commit that referenced this pull request Apr 20, 2014
…optimizations

commit 455bd4c upstream.

Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.

For instance in the following function:

void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
	waiter->magic = waiter;
	INIT_LIST_HEAD(&waiter->list);
}

compiled as:

800554d0 <debug_mutex_lock_common>:
800554d0:       e92d4008        push    {r3, lr}
800554d4:       e1a00001        mov     r0, r1
800554d8:       e3a02010        mov     r2, #16 ; 0x10
800554dc:       e3a01011        mov     r1, #17 ; 0x11
800554e0:       eb04426e        bl      80165ea0 <memset>
800554e4:       e1a03000        mov     r3, r0
800554e8:       e583000c        str     r0, [r3, #12]
800554ec:       e5830000        str     r0, [r3]
800554f:       e5830004        str     r0, [r3, #4]
800554f4:       e8bd8008        pop     {r3, pc}

GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.

This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:

Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).

Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:

save r8:
-       str     lr, [sp, #-4]!
+       stmfd   sp!, {r8, lr}

and restore r8 on both exit paths:
-       ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+       ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
(...)
        tst     r2, #16
        stmneia ip!, {r1, r3, r8, lr}
-       ldr     lr, [sp], #4
+       ldmfd   sp!, {r8, lr}

Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:

save r8:
-       stmfd   sp!, {r4-r7, lr}
+       stmfd   sp!, {r4-r8, lr}

and restore r8 on both exit paths:
        bgt     3b
-       ldmeqfd sp!, {r4-r7, pc}
+       ldmeqfd sp!, {r4-r8, pc}
(...)
        tst     r2, #16
        stmneia ip!, {r4-r7}
-       ldmfd   sp!, {r4-r7, lr}
+       ldmfd   sp!, {r4-r8, lr}

Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".

Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
mdrjr pushed a commit to ruppi/linux that referenced this pull request Jun 16, 2014
commit 057db84 upstream.

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)
  hardkernel#1 ffffffff810dc6b0 (asan_check_region+0x30/0x40)
  hardkernel#2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20)
  hardkernel#3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260)
  hardkernel#4 ffffffff812a1065 (__fput+0x155/0x360)
  hardkernel#5 ffffffff812a12de (____fput+0x1e/0x30)
  hardkernel#6 ffffffff8111708d (task_work_run+0x10d/0x140)
  hardkernel#7 ffffffff810ea043 (do_exit+0x433/0x11f0)
  hardkernel#8 ffffffff810eaee4 (do_group_exit+0x84/0x130)
  hardkernel#9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30)
  hardkernel#10 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Allocated by thread T5167:
  #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0)
  hardkernel#1 ffffffff8128337c (__kmalloc+0xbc/0x500)
  hardkernel#2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90)
  hardkernel#3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0)
  hardkernel#4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40)
  hardkernel#5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430)
  hardkernel#6 ffffffff8129b668 (finish_open+0x68/0xa0)
  hardkernel#7 ffffffff812b66ac (do_last+0xb8c/0x1710)
  hardkernel#8 ffffffff812b7350 (path_openat+0x120/0xb50)
  hardkernel#9 ffffffff812b8884 (do_filp_open+0x54/0xb0)
  hardkernel#10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0)
  hardkernel#11 ffffffff8129d4b7 (SyS_open+0x37/0x50)
  hardkernel#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/20131009222323.04fd1a0d@gandalf.local.home

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dsd pushed a commit to dsd/linux that referenced this pull request Jun 19, 2014
Since the commit below, cfg80211_chandef_dfs_required()
will warn if it gets a an NL80211_IFTYPE_UNSPECIFIED iftype
as explicitely written in the commit log.
When an virtual monitor interface is added, its type is set
in ieee80211_sub_if_data.vif.type, but not in
ieee80211_sub_if_data.wdev.iftype which is passed to
cfg80211_chandef_dfs_required() hence resulting in the
following warning:

WARNING: CPU: 1 PID: 21265 at net/wireless/chan.c:376 cfg80211_chandef_dfs_required+0xbc/0x130 [cfg80211]()
Modules linked in: [...]
CPU: 1 PID: 21265 Comm: ifconfig Tainted: G        W  O 3.13.11+ hardkernel#12
Hardware name: Dell Inc. Latitude E6410/0667CC, BIOS A01 03/05/2010
 0000000000000009 ffff88008f5fdb08 ffffffff817d4219 ffff88008f5fdb50
 ffff88008f5fdb40 ffffffff8106f57d 0000000000000000 0000000000000000
 ffff880081062fb8 ffff8800810604e0 0000000000000001 ffff88008f5fdba0
Call Trace:
 [<ffffffff817d4219>] dump_stack+0x4d/0x66
 [<ffffffff8106f57d>] warn_slowpath_common+0x7d/0xa0
 [<ffffffff8106f5ec>] warn_slowpath_fmt+0x4c/0x50
 [<ffffffffa04ea4ec>] cfg80211_chandef_dfs_required+0xbc/0x130 [cfg80211]
 [<ffffffffa06b1024>] ieee80211_vif_use_channel+0x94/0x500 [mac80211]
 [<ffffffffa0684e6b>] ieee80211_add_virtual_monitor+0x1ab/0x5c0 [mac80211]
 [<ffffffffa0686ae5>] ieee80211_do_open+0xe75/0x1580 [mac80211]
 [<ffffffffa0687259>] ieee80211_open+0x69/0x70 [mac80211]
[snip]

Fixes: 00ec75f ("cfg80211: pass the actual iftype when calling cfg80211_chandef_dfs_required()")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Acked-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
dsd pushed a commit to dsd/linux that referenced this pull request Jul 7, 2014
This patch tries to fix this crash:

 hardkernel#5 [ffff88003c1cd690] do_invalid_op at ffffffff810166d5
 hardkernel#6 [ffff88003c1cd730] invalid_op at ffffffff8159b2de
    [exception RIP: ocfs2_direct_IO_get_blocks+359]
    RIP: ffffffffa05dfa27  RSP: ffff88003c1cd7e8  RFLAGS: 00010202
    RAX: 0000000000000000  RBX: ffff88003c1cdaa8  RCX: 0000000000000000
    RDX: 000000000000000c  RSI: ffff880027a95000  RDI: ffff88003c79b540
    RBP: ffff88003c1cd858   R8: 0000000000000000   R9: ffffffff815f6ba0
    R10: 00000000000001c9  R11: 00000000000001c9  R12: ffff88002d271500
    R13: 0000000000000001  R14: 0000000000000000  R15: 0000000000001000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 hardkernel#7 [ffff88003c1cd860] do_direct_IO at ffffffff811cd31b
 hardkernel#8 [ffff88003c1cd950] direct_IO_iovec at ffffffff811cde9c
 hardkernel#9 [ffff88003c1cd9b0] do_blockdev_direct_IO at ffffffff811ce764
hardkernel#10 [ffff88003c1cdb80] __blockdev_direct_IO at ffffffff811ce7cc
hardkernel#11 [ffff88003c1cdbb0] ocfs2_direct_IO at ffffffffa05df756 [ocfs2]
hardkernel#12 [ffff88003c1cdbe0] generic_file_direct_write_iter at ffffffff8112f935
hardkernel#13 [ffff88003c1cdc40] ocfs2_file_write_iter at ffffffffa0600ccc [ocfs2]
hardkernel#14 [ffff88003c1cdd50] do_aio_write at ffffffff8119126c
hardkernel#15 [ffff88003c1cddc0] aio_rw_vect_retry at ffffffff811d9bb4
hardkernel#16 [ffff88003c1cddf0] aio_run_iocb at ffffffff811db880
hardkernel#17 [ffff88003c1cde30] io_submit_one at ffffffff811dc238
hardkernel#18 [ffff88003c1cde80] do_io_submit at ffffffff811dc437
hardkernel#19 [ffff88003c1cdf70] sys_io_submit at ffffffff811dc530
hardkernel#20 [ffff88003c1cdf80] system_call_fastpath at ffffffff8159a159

It crashes at
        BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED));
in ocfs2_direct_IO_get_blocks.

ocfs2_direct_IO_get_blocks is expecting the OCFS2_EXT_REFCOUNTED be removed in
ocfs2_prepare_inode_for_write() if it was there. But no cluster lock is taken
during the time before (or inside) ocfs2_prepare_inode_for_write() and after
ocfs2_direct_IO_get_blocks().

It can happen in this case:

Node A(which crashes)				Node B
------------------------                 ---------------------------
ocfs2_file_aio_write
  ocfs2_prepare_inode_for_write
    ocfs2_inode_lock
    ...
    ocfs2_inode_unlock
  #no refcount found
....					ocfs2_reflink
                                          ocfs2_inode_lock
                                          ...
                                          ocfs2_inode_unlock
                                          #now, refcount flag set on extent

                                        ...
                                        flush change to disk

ocfs2_direct_IO_get_blocks
  ocfs2_get_clusters
    #extent map miss
    #buffer_head miss
    read extents from disk
  found refcount flag on extent
  crash..

Fix:
Take rw_lock in ocfs2_reflink path

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mdrjr pushed a commit that referenced this pull request Jul 14, 2014
…s struct file

commit e4daf1f upstream.

The following call chain:
------------------------------------------------------------
nfs4_get_vfs_file
- nfsd_open
  - dentry_open
    - do_dentry_open
      - __get_file_write_access
        - get_write_access
          - return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
------------------------------------------------------------

can result in the following state:
------------------------------------------------------------
struct nfs4_file {
...
  fi_fds = {0xffff880c1fa65c80, 0xffffffffffffffe6, 0x0},
  fi_access = {{
      counter = 0x1
    }, {
      counter = 0x0
    }},
...
------------------------------------------------------------

1) First time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NULL, hence nfsd_open() is called where we get status set to an error
and fp->fi_fds[O_WRONLY] to -ETXTBSY. Thus we do not reach
nfs4_file_get_access() and fi_access[O_WRONLY] is not incremented.

2) Second time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NOT NULL (-ETXTBSY), so nfsd_open() is NOT called, but
nfs4_file_get_access() IS called and fi_access[O_WRONLY] is incremented.
Thus we leave a landmine in the form of the nfs4_file data structure in
an incorrect state.

3) Eventually, when __nfs4_file_put_access() is called it finds
fi_access[O_WRONLY] being non-zero, it decrements it and calls
nfs4_file_put_fd() which tries to fput -ETXTBSY.
------------------------------------------------------------
...
     [exception RIP: fput+0x9]
     RIP: ffffffff81177fa9  RSP: ffff88062e365c90  RFLAGS: 00010282
     RAX: ffff880c2b3d99cc  RBX: ffff880c2b3d9978  RCX: 0000000000000002
     RDX: dead000000100101  RSI: 0000000000000001  RDI: ffffffffffffffe6
     RBP: ffff88062e365c90   R8: ffff88041fe797d8   R9: ffff88062e365d58
     R10: 0000000000000008  R11: 0000000000000000  R12: 0000000000000001
     R13: 0000000000000007  R14: 0000000000000000  R15: 0000000000000000
     ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
  #9 [ffff88062e365c98] __nfs4_file_put_access at ffffffffa0562334 [nfsd]
 #10 [ffff88062e365cc8] nfs4_file_put_access at ffffffffa05623ab [nfsd]
 #11 [ffff88062e365ce8] free_generic_stateid at ffffffffa056634d [nfsd]
 #12 [ffff88062e365d18] release_open_stateid at ffffffffa0566e4b [nfsd]
 #13 [ffff88062e365d38] nfsd4_close at ffffffffa0567401 [nfsd]
 #14 [ffff88062e365d88] nfsd4_proc_compound at ffffffffa0557f28 [nfsd]
 #15 [ffff88062e365dd8] nfsd_dispatch at ffffffffa054543e [nfsd]
 #16 [ffff88062e365e18] svc_process_common at ffffffffa04ba5a4 [sunrpc]
 #17 [ffff88062e365e98] svc_process at ffffffffa04babe0 [sunrpc]
 #18 [ffff88062e365eb8] nfsd at ffffffffa0545b62 [nfsd]
 #19 [ffff88062e365ee8] kthread at ffffffff81090886
 #20 [ffff88062e365f48] kernel_thread at ffffffff8100c14a
------------------------------------------------------------


Signed-off-by: Harshula Jayasuriya <harshula@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
[xr: Backported to 3.4: adjust context]
Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jepler pushed a commit to jepler/odroid-linux that referenced this pull request Aug 7, 2014
Mike Galbraith captered the following:
| >hardkernel#11 [ffff88017b243e90] _raw_spin_lock at ffffffff815d2596
| >hardkernel#12 [ffff88017b243e90] rt_mutex_trylock at ffffffff815d15be
| >hardkernel#13 [ffff88017b243eb0] get_next_timer_interrupt at ffffffff81063b42
| >hardkernel#14 [ffff88017b243f00] tick_nohz_stop_sched_tick at ffffffff810bd1fd
| >hardkernel#15 [ffff88017b243f70] tick_nohz_irq_exit at ffffffff810bd7d2
| >hardkernel#16 [ffff88017b243f90] irq_exit at ffffffff8105b02d
| >hardkernel#17 [ffff88017b243fb0] reschedule_interrupt at ffffffff815db3dd
| >--- <IRQ stack> ---
| >hardkernel#18 [ffff88017a2a9bc8] reschedule_interrupt at ffffffff815db3dd
| >    [exception RIP: task_blocks_on_rt_mutex+51]
| >hardkernel#19 [ffff88017a2a9ce0] rt_spin_lock_slowlock at ffffffff815d183c
| >hardkernel#20 [ffff88017a2a9da0] lock_timer_base.isra.35 at ffffffff81061cbf
| >hardkernel#21 [ffff88017a2a9dd0] schedule_timeout at ffffffff815cf1ce
| >hardkernel#22 [ffff88017a2a9e50] rcu_gp_kthread at ffffffff810f9bbb
| >hardkernel#23 [ffff88017a2a9ed0] kthread at ffffffff810796d5
| >hardkernel#24 [ffff88017a2a9f50] ret_from_fork at ffffffff815da04c

lock_timer_base() does a try_lock() which deadlocks on the waiter lock
not the lock itself.
This patch takes the waiter_lock with trylock so it should work from interrupt
context as well. If the fastpath doesn't work and the waiter_lock itself is
taken then it seems that the lock itself taken.
This patch also adds a "rt_spin_try_unlock" to keep lockdep happy. If we
managed to take the wait_lock in the first place we should also be able
to take it in the unlock path.

Cc: stable-rt@vger.kernel.org
Reported-by: Mike Galbraith <bitbucket@online.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
paralin pushed a commit to paralin/linux that referenced this pull request Aug 14, 2015
With the nonatomic PCM ops, the system may spew lockdep warnings like:

 =============================================
 [ INFO: possible recursive locking detected ]
 4.2.0-rc1-jeejaval3 hardkernel#12 Not tainted
 ---------------------------------------------
 aplay/4029 is trying to acquire lock:
  (snd_pcm_link_rwsem){.+.+.+}, at: [<ffffffff816fd473>] snd_pcm_stream_lock+0x43/0x60

 but task is already holding lock:
  (snd_pcm_link_rwsem){.+.+.+}, at: [<ffffffff816fcf29>] snd_pcm_action_nonatomic+0x29/0x80

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

        CPU0
        ----
   lock(snd_pcm_link_rwsem);
   lock(snd_pcm_link_rwsem);

Although this is false-positive as the rwsem is taken always as
read-only for these code paths, it's certainly annoying to see this at
any occasion.  A simple fix is to use down_read_nested() in
snd_pcm_stream_lock() that can be called inside another lock.

Reported-by: Vinod Koul <vinod.koul@intel.com>
Reported-by: Jeeja Kp <jeeja.kp@intel.com>
Tested-by: Jeeja Kp <jeeja.kp@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
paralin pushed a commit to paralin/linux that referenced this pull request Aug 14, 2015
Nikolay has reported a hang when a memcg reclaim got stuck with the
following backtrace:

PID: 18308  TASK: ffff883d7c9b0a30  CPU: 1   COMMAND: "rsync"
  #0 __schedule at ffffffff815ab152
  hardkernel#1 schedule at ffffffff815ab76e
  hardkernel#2 schedule_timeout at ffffffff815ae5e5
  hardkernel#3 io_schedule_timeout at ffffffff815aad6a
  hardkernel#4 bit_wait_io at ffffffff815abfc6
  hardkernel#5 __wait_on_bit at ffffffff815abda5
  hardkernel#6 wait_on_page_bit at ffffffff8111fd4f
  hardkernel#7 shrink_page_list at ffffffff81135445
  hardkernel#8 shrink_inactive_list at ffffffff81135845
  hardkernel#9 shrink_lruvec at ffffffff81135ead
 hardkernel#10 shrink_zone at ffffffff811360c3
 hardkernel#11 shrink_zones at ffffffff81136eff
 hardkernel#12 do_try_to_free_pages at ffffffff8113712f
 hardkernel#13 try_to_free_mem_cgroup_pages at ffffffff811372be
 hardkernel#14 try_charge at ffffffff81189423
 hardkernel#15 mem_cgroup_try_charge at ffffffff8118c6f5
 hardkernel#16 __add_to_page_cache_locked at ffffffff8112137d
 hardkernel#17 add_to_page_cache_lru at ffffffff81121618
 hardkernel#18 pagecache_get_page at ffffffff8112170b
 hardkernel#19 grow_dev_page at ffffffff811c8297
 hardkernel#20 __getblk_slow at ffffffff811c91d6
 hardkernel#21 __getblk_gfp at ffffffff811c92c1
 hardkernel#22 ext4_ext_grow_indepth at ffffffff8124565c
 hardkernel#23 ext4_ext_create_new_leaf at ffffffff81246ca8
 hardkernel#24 ext4_ext_insert_extent at ffffffff81246f09
 hardkernel#25 ext4_ext_map_blocks at ffffffff8124a848
 hardkernel#26 ext4_map_blocks at ffffffff8121a5b7
 hardkernel#27 mpage_map_one_extent at ffffffff8121b1fa
 hardkernel#28 mpage_map_and_submit_extent at ffffffff8121f07b
 hardkernel#29 ext4_writepages at ffffffff8121f6d5
 hardkernel#30 do_writepages at ffffffff8112c490
 hardkernel#31 __filemap_fdatawrite_range at ffffffff81120199
 hardkernel#32 filemap_flush at ffffffff8112041c
 hardkernel#33 ext4_alloc_da_blocks at ffffffff81219da1
 hardkernel#34 ext4_rename at ffffffff81229b91
 hardkernel#35 ext4_rename2 at ffffffff81229e32
 hardkernel#36 vfs_rename at ffffffff811a08a5
 hardkernel#37 SYSC_renameat2 at ffffffff811a3ffc
 hardkernel#38 sys_renameat2 at ffffffff811a408e
 hardkernel#39 sys_rename at ffffffff8119e51e
 hardkernel#40 system_call_fastpath at ffffffff815afa89

Dave Chinner has properly pointed out that this is a deadlock in the
reclaim code because ext4 doesn't submit pages which are marked by
PG_writeback right away.

The heuristic was introduced by commit e62e384 ("memcg: prevent OOM
with too many dirty pages") and it was applied only when may_enter_fs
was specified.  The code has been changed by c3b94f4 ("memcg:
further prevent OOM with too many dirty pages") which has removed the
__GFP_FS restriction with a reasoning that we do not get into the fs
code.  But this is not sufficient apparently because the fs doesn't
necessarily submit pages marked PG_writeback for IO right away.

ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily
submit the bio.  Instead it tries to map more pages into the bio and
mpage_map_one_extent might trigger memcg charge which might end up
waiting on a page which is marked PG_writeback but hasn't been submitted
yet so we would end up waiting for something that never finishes.

Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2)
before we go to wait on the writeback.  The page fault path, which is
the only path that triggers memcg oom killer since 3.12, shouldn't
require GFP_NOFS and so we shouldn't reintroduce the premature OOM
killer issue which was originally addressed by the heuristic.

As per David Chinner the xfs is doing similar thing since 2.6.15 already
so ext4 is not the only affected filesystem.  Moreover he notes:

: For example: IO completion might require unwritten extent conversion
: which executes filesystem transactions and GFP_NOFS allocations. The
: writeback flag on the pages can not be cleared until unwritten
: extent conversion completes. Hence memory reclaim cannot wait on
: page writeback to complete in GFP_NOFS context because it is not
: safe to do so, memcg reclaim or otherwise.

Cc: stable@vger.kernel.org # 3.9+
[tytso@mit.edu: corrected the control flow]
Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages")
Reported-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mihailescu2m pushed a commit to mihailescu2m/linux that referenced this pull request Aug 25, 2016
arm_pmu_mutex is never held long and we don't want to sleep while the
lock is being held as it's executed in the context of hotplug notifiers.
So it can be converted to a simple spinlock instead.

Without this patch we get the following warning:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/2
no locks held by swapper/2/0.
irq event stamp: 381314
hardirqs last  enabled at (381313): _raw_spin_unlock_irqrestore+0x7c/0x88
hardirqs last disabled at (381314): cpu_die+0x28/0x48
softirqs last  enabled at (381294): _local_bh_enable+0x28/0x50
softirqs last disabled at (381293): irq_enter+0x58/0x78
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.7.0 hardkernel#12
Call trace:
 dump_backtrace+0x0/0x220
 show_stack+0x24/0x30
 dump_stack+0xb4/0xf0
 ___might_sleep+0x1d8/0x1f0
 __might_sleep+0x5c/0x98
 mutex_lock_nested+0x54/0x400
 arm_perf_starting_cpu+0x34/0xb0
 cpuhp_invoke_callback+0x88/0x3d8
 notify_cpu_starting+0x78/0x98
 secondary_start_kernel+0x108/0x1a8

This patch converts the mutex to spinlock to eliminate the above
warnings. This constraints pmu->reset to be non-blocking call which is
the case with all the ARM PMU backends.

Cc: Stephen Boyd <sboyd@codeaurora.org>
Fixes: 37b502f ("arm/perf: Fix hotplug state machine conversion")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Dmole pushed a commit to Dmole/linux that referenced this pull request Oct 29, 2016
commit b6bc1c7 upstream.

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

The crash:

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

Fixes: 632bc3f ("IB/core, RDMA RW API: Do not exceed QP SGE send limit")
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dmole pushed a commit to Dmole/linux that referenced this pull request Jan 9, 2017
commit 4dfce57 upstream.

There have been several reports over the years of NULL pointer
dereferences in xfs_trans_log_inode during xfs_fsr processes,
when the process is doing an fput and tearing down extents
on the temporary inode, something like:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
PID: 29439  TASK: ffff880550584fa0  CPU: 6   COMMAND: "xfs_fsr"
    [exception RIP: xfs_trans_log_inode+0x10]
 hardkernel#9 [ffff8800a57bbbe0] xfs_bunmapi at ffffffffa037398e [xfs]
hardkernel#10 [ffff8800a57bbce8] xfs_itruncate_extents at ffffffffa0391b29 [xfs]
hardkernel#11 [ffff8800a57bbd88] xfs_inactive_truncate at ffffffffa0391d0c [xfs]
hardkernel#12 [ffff8800a57bbdb8] xfs_inactive at ffffffffa0392508 [xfs]
hardkernel#13 [ffff8800a57bbdd8] xfs_fs_evict_inode at ffffffffa035907e [xfs]
hardkernel#14 [ffff8800a57bbe00] evict at ffffffff811e1b67
hardkernel#15 [ffff8800a57bbe28] iput at ffffffff811e23a5
hardkernel#16 [ffff8800a57bbe58] dentry_kill at ffffffff811dcfc8
hardkernel#17 [ffff8800a57bbe88] dput at ffffffff811dd06c
hardkernel#18 [ffff8800a57bbea8] __fput at ffffffff811c823b
hardkernel#19 [ffff8800a57bbef0] ____fput at ffffffff811c846e
hardkernel#20 [ffff8800a57bbf00] task_work_run at ffffffff81093b27
hardkernel#21 [ffff8800a57bbf30] do_notify_resume at ffffffff81013b0c
hardkernel#22 [ffff8800a57bbf50] int_signal at ffffffff8161405d

As it turns out, this is because the i_itemp pointer, along
with the d_ops pointer, has been overwritten with zeros
when we tear down the extents during truncate.  When the in-core
inode fork on the temporary inode used by xfs_fsr was originally
set up during the extent swap, we mistakenly looked at di_nextents
to determine whether all extents fit inline, but this misses extents
generated by speculative preallocation; we should be using if_bytes
instead.

This mistake corrupts the in-memory inode, and code in
xfs_iext_remove_inline eventually gets bad inputs, causing
it to memmove and memset incorrect ranges; this became apparent
because the two values in ifp->if_u2.if_inline_ext[1] contained
what should have been in d_ops and i_itemp; they were memmoved due
to incorrect array indexing and then the original locations
were zeroed with memset, again due to an array overrun.

Fix this by properly using i_df.if_bytes to determine the number
of extents, not di_nextents.

Thanks to dchinner for looking at this with me and spotting the
root cause.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dmole pushed a commit to Dmole/linux that referenced this pull request Mar 22, 2017
[ Upstream commit 45caeaa ]

As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 hardkernel#8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 hardkernel#9 [] tcp_rcv_established at ffffffff81580b64
hardkernel#10 [] tcp_v4_do_rcv at ffffffff8158b54a
hardkernel#11 [] tcp_v4_rcv at ffffffff8158cd02
hardkernel#12 [] ip_local_deliver_finish at ffffffff815668f4
hardkernel#13 [] ip_local_deliver at ffffffff81566bd9
hardkernel#14 [] ip_rcv_finish at ffffffff8156656d
hardkernel#15 [] ip_rcv at ffffffff81566f06
hardkernel#16 [] __netif_receive_skb_core at ffffffff8152b3a2
hardkernel#17 [] __netif_receive_skb at ffffffff8152b608
hardkernel#18 [] netif_receive_skb at ffffffff8152b690
hardkernel#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
hardkernel#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
hardkernel#21 [] net_rx_action at ffffffff8152bac2
hardkernel#22 [] __do_softirq at ffffffff81084b4f
hardkernel#23 [] call_softirq at ffffffff8164845c
hardkernel#24 [] do_softirq at ffffffff81016fc5
hardkernel#25 [] irq_exit at ffffffff81084ee5
hardkernel#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)↩
 225 {↩
 226 ▹       const struct inet_connection_sock *icsk = inet_csk(sk);↩
 227 ▹       const struct dst_entry *dst = __sk_dst_get(sk);↩
 228 ↩
 229 ▹       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
 230 ▹       ▹       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
 231 }↩

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb3320 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <egarver@redhat.com>
Cc: Hannes Sowa <hsowa@redhat.com>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dmole pushed a commit to Dmole/linux that referenced this pull request Mar 22, 2017
[ Upstream commit 45caeaa ]

As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 hardkernel#8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 hardkernel#9 [] tcp_rcv_established at ffffffff81580b64
hardkernel#10 [] tcp_v4_do_rcv at ffffffff8158b54a
hardkernel#11 [] tcp_v4_rcv at ffffffff8158cd02
hardkernel#12 [] ip_local_deliver_finish at ffffffff815668f4
hardkernel#13 [] ip_local_deliver at ffffffff81566bd9
hardkernel#14 [] ip_rcv_finish at ffffffff8156656d
hardkernel#15 [] ip_rcv at ffffffff81566f06
hardkernel#16 [] __netif_receive_skb_core at ffffffff8152b3a2
hardkernel#17 [] __netif_receive_skb at ffffffff8152b608
hardkernel#18 [] netif_receive_skb at ffffffff8152b690
hardkernel#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
hardkernel#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
hardkernel#21 [] net_rx_action at ffffffff8152bac2
hardkernel#22 [] __do_softirq at ffffffff81084b4f
hardkernel#23 [] call_softirq at ffffffff8164845c
hardkernel#24 [] do_softirq at ffffffff81016fc5
hardkernel#25 [] irq_exit at ffffffff81084ee5
hardkernel#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)↩
 225 {↩
 226 ▹       const struct inet_connection_sock *icsk = inet_csk(sk);↩
 227 ▹       const struct dst_entry *dst = __sk_dst_get(sk);↩
 228 ↩
 229 ▹       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
 230 ▹       ▹       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
 231 }↩

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb3320 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <egarver@redhat.com>
Cc: Hannes Sowa <hsowa@redhat.com>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dmole pushed a commit to Dmole/linux that referenced this pull request Mar 30, 2017
commit 4dfce57 upstream.

There have been several reports over the years of NULL pointer
dereferences in xfs_trans_log_inode during xfs_fsr processes,
when the process is doing an fput and tearing down extents
on the temporary inode, something like:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
PID: 29439  TASK: ffff880550584fa0  CPU: 6   COMMAND: "xfs_fsr"
    [exception RIP: xfs_trans_log_inode+0x10]
 hardkernel#9 [ffff8800a57bbbe0] xfs_bunmapi at ffffffffa037398e [xfs]
hardkernel#10 [ffff8800a57bbce8] xfs_itruncate_extents at ffffffffa0391b29 [xfs]
hardkernel#11 [ffff8800a57bbd88] xfs_inactive_truncate at ffffffffa0391d0c [xfs]
hardkernel#12 [ffff8800a57bbdb8] xfs_inactive at ffffffffa0392508 [xfs]
hardkernel#13 [ffff8800a57bbdd8] xfs_fs_evict_inode at ffffffffa035907e [xfs]
hardkernel#14 [ffff8800a57bbe00] evict at ffffffff811e1b67
hardkernel#15 [ffff8800a57bbe28] iput at ffffffff811e23a5
hardkernel#16 [ffff8800a57bbe58] dentry_kill at ffffffff811dcfc8
hardkernel#17 [ffff8800a57bbe88] dput at ffffffff811dd06c
hardkernel#18 [ffff8800a57bbea8] __fput at ffffffff811c823b
hardkernel#19 [ffff8800a57bbef0] ____fput at ffffffff811c846e
hardkernel#20 [ffff8800a57bbf00] task_work_run at ffffffff81093b27
hardkernel#21 [ffff8800a57bbf30] do_notify_resume at ffffffff81013b0c
hardkernel#22 [ffff8800a57bbf50] int_signal at ffffffff8161405d

As it turns out, this is because the i_itemp pointer, along
with the d_ops pointer, has been overwritten with zeros
when we tear down the extents during truncate.  When the in-core
inode fork on the temporary inode used by xfs_fsr was originally
set up during the extent swap, we mistakenly looked at di_nextents
to determine whether all extents fit inline, but this misses extents
generated by speculative preallocation; we should be using if_bytes
instead.

This mistake corrupts the in-memory inode, and code in
xfs_iext_remove_inline eventually gets bad inputs, causing
it to memmove and memset incorrect ranges; this became apparent
because the two values in ifp->if_u2.if_inline_ext[1] contained
what should have been in d_ops and i_itemp; they were memmoved due
to incorrect array indexing and then the original locations
were zeroed with memset, again due to an array overrun.

Fix this by properly using i_df.if_bytes to determine the number
of extents, not di_nextents.

Thanks to dchinner for looking at this with me and spotting the
root cause.

[nborisov: backported to 4.4]

Cc: stable@vger.kernel.org
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--
 fs/xfs/xfs_bmap_util.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
Dmole pushed a commit to Dmole/linux that referenced this pull request Jun 24, 2017
commit ba80aa9 upstream.

This patch closes a long standing race in configfs between
the creation of a new symlink in create_link(), while the
symlink target's config_item is being concurrently removed
via configfs_rmdir().

This can happen because the symlink target's reference
is obtained by config_item_get() in create_link() before
the CONFIGFS_USET_DROPPING bit set by configfs_detach_prep()
during configfs_rmdir() shutdown is actually checked..

This originally manifested itself on ppc64 on v4.8.y under
heavy load using ibmvscsi target ports with Novalink API:

[ 7877.289863] rpadlpar_io: slot U8247.22L.212A91A-V1-C8 added
[ 7879.893760] ------------[ cut here ]------------
[ 7879.893768] WARNING: CPU: 15 PID: 17585 at ./include/linux/kref.h:46 config_item_get+0x7c/0x90 [configfs]
[ 7879.893811] CPU: 15 PID: 17585 Comm: targetcli Tainted: G           O 4.8.17-customv2.22 hardkernel#12
[ 7879.893812] task: c00000018a0d3400 task.stack: c0000001f3b40000
[ 7879.893813] NIP: d000000002c664ec LR: d000000002c60980 CTR: c000000000b70870
[ 7879.893814] REGS: c0000001f3b43810 TRAP: 0700   Tainted: G O     (4.8.17-customv2.22)
[ 7879.893815] MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 28222242  XER: 00000000
[ 7879.893820] CFAR: d000000002c664bc SOFTE: 1
                GPR00: d000000002c60980 c0000001f3b43a90 d000000002c70908 c0000000fbc06820
                GPR04: c0000001ef1bd900 0000000000000004 0000000000000001 0000000000000000
                GPR08: 0000000000000000 0000000000000001 d000000002c69560 d000000002c66d80
                GPR12: c000000000b70870 c00000000e798700 c0000001f3b43ca0 c0000001d4949d40
                GPR16: c00000014637e1c0 0000000000000000 0000000000000000 c0000000f2392940
                GPR20: c0000001f3b43b98 0000000000000041 0000000000600000 0000000000000000
                GPR24: fffffffffffff000 0000000000000000 d000000002c60be0 c0000001f1dac490
                GPR28: 0000000000000004 0000000000000000 c0000001ef1bd900 c0000000f2392940
[ 7879.893839] NIP [d000000002c664ec] config_item_get+0x7c/0x90 [configfs]
[ 7879.893841] LR [d000000002c60980] check_perm+0x80/0x2e0 [configfs]
[ 7879.893842] Call Trace:
[ 7879.893844] [c0000001f3b43ac0] [d000000002c60980] check_perm+0x80/0x2e0 [configfs]
[ 7879.893847] [c0000001f3b43b10] [c000000000329770] do_dentry_open+0x2c0/0x460
[ 7879.893849] [c0000001f3b43b70] [c000000000344480] path_openat+0x210/0x1490
[ 7879.893851] [c0000001f3b43c80] [c00000000034708c] do_filp_open+0xfc/0x170
[ 7879.893853] [c0000001f3b43db0] [c00000000032b5bc] do_sys_open+0x1cc/0x390
[ 7879.893856] [c0000001f3b43e30] [c000000000009584] system_call+0x38/0xec
[ 7879.893856] Instruction dump:
[ 7879.893858] 409d0014 38210030 e8010010 7c0803a6 4e800020 3d220000 e94981e0 892a0000
[ 7879.893861] 2f890000 409effe0 39200001 992a0000 <0fe00000> 4bffffd0 60000000 60000000
[ 7879.893866] ---[ end trace 14078f0b3b5ad0aa ]---

To close this race, go ahead and obtain the symlink's target
config_item reference only after the existing CONFIGFS_USET_DROPPING
check succeeds.

This way, if configfs_rmdir() wins create_link() will return -ENONET,
and if create_link() wins configfs_rmdir() will return -EBUSY.

Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dmole pushed a commit to Dmole/linux that referenced this pull request Jun 29, 2017
commit ba80aa9 upstream.

This patch closes a long standing race in configfs between
the creation of a new symlink in create_link(), while the
symlink target's config_item is being concurrently removed
via configfs_rmdir().

This can happen because the symlink target's reference
is obtained by config_item_get() in create_link() before
the CONFIGFS_USET_DROPPING bit set by configfs_detach_prep()
during configfs_rmdir() shutdown is actually checked..

This originally manifested itself on ppc64 on v4.8.y under
heavy load using ibmvscsi target ports with Novalink API:

[ 7877.289863] rpadlpar_io: slot U8247.22L.212A91A-V1-C8 added
[ 7879.893760] ------------[ cut here ]------------
[ 7879.893768] WARNING: CPU: 15 PID: 17585 at ./include/linux/kref.h:46 config_item_get+0x7c/0x90 [configfs]
[ 7879.893811] CPU: 15 PID: 17585 Comm: targetcli Tainted: G           O 4.8.17-customv2.22 hardkernel#12
[ 7879.893812] task: c00000018a0d3400 task.stack: c0000001f3b40000
[ 7879.893813] NIP: d000000002c664ec LR: d000000002c60980 CTR: c000000000b70870
[ 7879.893814] REGS: c0000001f3b43810 TRAP: 0700   Tainted: G O     (4.8.17-customv2.22)
[ 7879.893815] MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 28222242  XER: 00000000
[ 7879.893820] CFAR: d000000002c664bc SOFTE: 1
                GPR00: d000000002c60980 c0000001f3b43a90 d000000002c70908 c0000000fbc06820
                GPR04: c0000001ef1bd900 0000000000000004 0000000000000001 0000000000000000
                GPR08: 0000000000000000 0000000000000001 d000000002c69560 d000000002c66d80
                GPR12: c000000000b70870 c00000000e798700 c0000001f3b43ca0 c0000001d4949d40
                GPR16: c00000014637e1c0 0000000000000000 0000000000000000 c0000000f2392940
                GPR20: c0000001f3b43b98 0000000000000041 0000000000600000 0000000000000000
                GPR24: fffffffffffff000 0000000000000000 d000000002c60be0 c0000001f1dac490
                GPR28: 0000000000000004 0000000000000000 c0000001ef1bd900 c0000000f2392940
[ 7879.893839] NIP [d000000002c664ec] config_item_get+0x7c/0x90 [configfs]
[ 7879.893841] LR [d000000002c60980] check_perm+0x80/0x2e0 [configfs]
[ 7879.893842] Call Trace:
[ 7879.893844] [c0000001f3b43ac0] [d000000002c60980] check_perm+0x80/0x2e0 [configfs]
[ 7879.893847] [c0000001f3b43b10] [c000000000329770] do_dentry_open+0x2c0/0x460
[ 7879.893849] [c0000001f3b43b70] [c000000000344480] path_openat+0x210/0x1490
[ 7879.893851] [c0000001f3b43c80] [c00000000034708c] do_filp_open+0xfc/0x170
[ 7879.893853] [c0000001f3b43db0] [c00000000032b5bc] do_sys_open+0x1cc/0x390
[ 7879.893856] [c0000001f3b43e30] [c000000000009584] system_call+0x38/0xec
[ 7879.893856] Instruction dump:
[ 7879.893858] 409d0014 38210030 e8010010 7c0803a6 4e800020 3d220000 e94981e0 892a0000
[ 7879.893861] 2f890000 409effe0 39200001 992a0000 <0fe00000> 4bffffd0 60000000 60000000
[ 7879.893866] ---[ end trace 14078f0b3b5ad0aa ]---

To close this race, go ahead and obtain the symlink's target
config_item reference only after the existing CONFIGFS_USET_DROPPING
check succeeds.

This way, if configfs_rmdir() wins create_link() will return -ENONET,
and if create_link() wins configfs_rmdir() will return -EBUSY.

Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mdrjr pushed a commit that referenced this pull request Sep 4, 2017
commit 45caeaa upstream.

As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 #8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 #9 [] tcp_rcv_established at ffffffff81580b64
#10 [] tcp_v4_do_rcv at ffffffff8158b54a
#11 [] tcp_v4_rcv at ffffffff8158cd02
#12 [] ip_local_deliver_finish at ffffffff815668f4
#13 [] ip_local_deliver at ffffffff81566bd9
#14 [] ip_rcv_finish at ffffffff8156656d
#15 [] ip_rcv at ffffffff81566f06
#16 [] __netif_receive_skb_core at ffffffff8152b3a2
#17 [] __netif_receive_skb at ffffffff8152b608
#18 [] netif_receive_skb at ffffffff8152b690
#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
#21 [] net_rx_action at ffffffff8152bac2
#22 [] __do_softirq at ffffffff81084b4f
#23 [] call_softirq at ffffffff8164845c
#24 [] do_softirq at ffffffff81016fc5
#25 [] irq_exit at ffffffff81084ee5
#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)�
 225 {�
 226 �       const struct inet_connection_sock *icsk = inet_csk(sk);�
 227 �       const struct dst_entry *dst = __sk_dst_get(sk);�
 228 �
 229 �       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||�
 230 �       �       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);�
 231 }�

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb3320 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <egarver@redhat.com>
Cc: Hannes Sowa <hsowa@redhat.com>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
mihailescu2m pushed a commit to mihailescu2m/linux that referenced this pull request Oct 31, 2017
spin_lock/unlock of health->wq_lock should be IRQ safe.
It was changed to spin_lock_irqsave since adding commit 0179720
("net/mlx5: Introduce trigger_health_work function") which uses
spin_lock from asynchronous event (IRQ) context.
Thus, all spin_lock/unlock of health->wq_lock should have been moved
to IRQ safe mode.
However, one occurrence on new code using this lock missed that
change, resulting in possible deadlock:
  kernel: Possible unsafe locking scenario:
  kernel:       CPU0
  kernel:       ----
  kernel:  lock(&(&health->wq_lock)->rlock);
  kernel:  <Interrupt>
  kernel:    lock(&(&health->wq_lock)->rlock);
  kernel: hardkernel#12 *** DEADLOCK ***

Fixes: 2a0165a ("net/mlx5: Cancel delayed recovery work when unloading the driver")
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
mdrjr pushed a commit that referenced this pull request Apr 4, 2018
[ Upstream commit 191f86c ]

The seg6_build_state() function is called with RCU read lock held,
so we cannot use GFP_KERNEL. This patch uses GFP_ATOMIC instead.

[   92.770271] =============================
[   92.770628] WARNING: suspicious RCU usage
[   92.770921] 4.16.0-rc4+ #12 Not tainted
[   92.771277] -----------------------------
[   92.771585] ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section!
[   92.772279]
[   92.772279] other info that might help us debug this:
[   92.772279]
[   92.773067]
[   92.773067] rcu_scheduler_active = 2, debug_locks = 1
[   92.773514] 2 locks held by ip/2413:
[   92.773765]  #0:  (rtnl_mutex){+.+.}, at: [<00000000e5461720>] rtnetlink_rcv_msg+0x441/0x4d0
[   92.774377]  #1:  (rcu_read_lock){....}, at: [<00000000df4f161e>] lwtunnel_build_state+0x59/0x210
[   92.775065]
[   92.775065] stack backtrace:
[   92.775371] CPU: 0 PID: 2413 Comm: ip Not tainted 4.16.0-rc4+ #12
[   92.775791] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc27 04/01/2014
[   92.776608] Call Trace:
[   92.776852]  dump_stack+0x7d/0xbc
[   92.777130]  __schedule+0x133/0xf00
[   92.777393]  ? unwind_get_return_address_ptr+0x50/0x50
[   92.777783]  ? __sched_text_start+0x8/0x8
[   92.778073]  ? rcu_is_watching+0x19/0x30
[   92.778383]  ? kernel_text_address+0x49/0x60
[   92.778800]  ? __kernel_text_address+0x9/0x30
[   92.779241]  ? unwind_get_return_address+0x29/0x40
[   92.779727]  ? pcpu_alloc+0x102/0x8f0
[   92.780101]  _cond_resched+0x23/0x50
[   92.780459]  __mutex_lock+0xbd/0xad0
[   92.780818]  ? pcpu_alloc+0x102/0x8f0
[   92.781194]  ? seg6_build_state+0x11d/0x240
[   92.781611]  ? save_stack+0x9b/0xb0
[   92.781965]  ? __ww_mutex_wakeup_for_backoff+0xf0/0xf0
[   92.782480]  ? seg6_build_state+0x11d/0x240
[   92.782925]  ? lwtunnel_build_state+0x1bd/0x210
[   92.783393]  ? ip6_route_info_create+0x687/0x1640
[   92.783846]  ? ip6_route_add+0x74/0x110
[   92.784236]  ? inet6_rtm_newroute+0x8a/0xd0

Fixes: 6c8702c ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mdrjr pushed a commit that referenced this pull request May 22, 2018
[ Upstream commit af50e4b ]

syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dmole pushed a commit to Dmole/linux that referenced this pull request May 31, 2018
[ Upstream commit 2bbea6e ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 hardkernel#1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 hardkernel#2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 hardkernel#3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 hardkernel#4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 hardkernel#5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 hardkernel#6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 hardkernel#7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 hardkernel#8 [ffff880078447da8] mount_bdev at ffffffff81202570
 hardkernel#9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
hardkernel#10 [ffff880078447e28] mount_fs at ffffffff81202d09
hardkernel#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
hardkernel#12 [ffff880078447ea8] do_mount at ffffffff81220fee
hardkernel#13 [ffff880078447f28] sys_mount at ffffffff812218d6
hardkernel#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 hardkernel#1 [ffff880078417900] schedule at ffffffff8168dc59
 hardkernel#2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 hardkernel#3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 hardkernel#4 [ffff8800784179d0] down_read at ffffffff8168cde0
 hardkernel#5 [ffff8800784179e8] get_super at ffffffff81201cc7
 hardkernel#6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 hardkernel#7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 hardkernel#8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 hardkernel#9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
hardkernel#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
hardkernel#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
hardkernel#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
hardkernel#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
hardkernel#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
hardkernel#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
hardkernel#16 [ffff880078417d00] do_last at ffffffff8120d53d
hardkernel#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
hardkernel#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
hardkernel#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
hardkernel#20 [ffff880078417f70] sys_open at ffffffff811fde4e
hardkernel#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dmole pushed a commit to Dmole/linux that referenced this pull request May 31, 2018
[ Upstream commit fca3234 ]

Executing command 'perf stat -T -- ls' dumps core on x86 and s390.

Here is the call back chain (done on x86):

 # gdb ./perf
 ....
 (gdb) r stat -T -- ls
...
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
(gdb) where
 #0  0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
 hardkernel#1  0x00007ffff56ae484 in asprintf () from /lib64/libc.so.6
 hardkernel#2  0x00000000004f1982 in __parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930, auto_merge_stats=false) at util/parse-events.c:1233
 hardkernel#3  0x00000000004f1c8e in parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930) at util/parse-events.c:1288
 hardkernel#4  0x0000000000537ce3 in parse_events_parse (_parse_state=0x7fffffffd580,
    scanner=0xbf4210) at util/parse-events.y:234
 hardkernel#5  0x00000000004f2c7a in parse_events__scanner (str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}",
    parse_state=0x7fffffffd580, start_token=258) at util/parse-events.c:1673
 hardkernel#6  0x00000000004f2e23 in parse_events (evlist=0xbe9990, str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}", err=0x0)
    at util/parse-events.c:1713
 hardkernel#7  0x000000000044e137 in add_default_attributes () at builtin-stat.c:2281
 hardkernel#8  0x000000000044f7b5 in cmd_stat (argc=1, argv=0x7fffffffe3b0) at
    builtin-stat.c:2828
 hardkernel#9  0x00000000004c8b0f in run_builtin (p=0xab01a0 <commands+288>, argc=4,
    argv=0x7fffffffe3b0) at perf.c:297
 hardkernel#10 0x00000000004c8d7c in handle_internal_command (argc=4,
    argv=0x7fffffffe3b0) at perf.c:349
 hardkernel#11 0x00000000004c8ece in run_argv (argcp=0x7fffffffe20c,
   argv=0x7fffffffe200) at perf.c:393
 hardkernel#12 0x00000000004c929c in main (argc=4, argv=0x7fffffffe3b0) at perf.c:537
(gdb)

It turns out that a NULL pointer is referenced. Here are the
function calls:

  ...
  cmd_stat()
  +---> add_default_attributes()
	+---> parse_events(evsel_list, transaction_attrs, NULL);
	             3rd parameter set to NULL

Function parse_events(xx, xx, struct parse_events_error *err) dives
into a bison generated scanner and creates
parser state information for it first:

   struct parse_events_state parse_state = {
                .list   = LIST_HEAD_INIT(parse_state.list),
                .idx    = evlist->nr_entries,
                .error  = err,   <--- NULL POINTER !!!
                .evlist = evlist,
        };

Now various functions inside the bison scanner are called to end up in
__parse_events_add_pmu(struct parse_events_state *parse_state, ..) with
first parameter being a pointer to above structure definition.

Now the PMU event name is not found (because being executed in a VM) and
this function tries to create an error message with

   asprintf(&parse_state->error.str, ....)

which references a NULL pointer and dumps core.

Fix this by providing a pointer to the necessary error information
instead of NULL. Technically only the else part is needed to avoid the
core dump, just lets be safe...

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180308145735.64717-1-tmricht@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dmole pushed a commit to Dmole/linux that referenced this pull request May 31, 2018
[ Upstream commit 2bbea6e ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 hardkernel#1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 hardkernel#2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 hardkernel#3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 hardkernel#4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 hardkernel#5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 hardkernel#6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 hardkernel#7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 hardkernel#8 [ffff880078447da8] mount_bdev at ffffffff81202570
 hardkernel#9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
hardkernel#10 [ffff880078447e28] mount_fs at ffffffff81202d09
hardkernel#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
hardkernel#12 [ffff880078447ea8] do_mount at ffffffff81220fee
hardkernel#13 [ffff880078447f28] sys_mount at ffffffff812218d6
hardkernel#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 hardkernel#1 [ffff880078417900] schedule at ffffffff8168dc59
 hardkernel#2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 hardkernel#3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 hardkernel#4 [ffff8800784179d0] down_read at ffffffff8168cde0
 hardkernel#5 [ffff8800784179e8] get_super at ffffffff81201cc7
 hardkernel#6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 hardkernel#7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 hardkernel#8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 hardkernel#9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
hardkernel#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
hardkernel#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
hardkernel#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
hardkernel#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
hardkernel#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
hardkernel#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
hardkernel#16 [ffff880078417d00] do_last at ffffffff8120d53d
hardkernel#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
hardkernel#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
hardkernel#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
hardkernel#20 [ffff880078417f70] sys_open at ffffffff811fde4e
hardkernel#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dmole pushed a commit to Dmole/linux that referenced this pull request Jul 7, 2018
…sion

commit 8afb1d2 upstream.

Commit 40f70c0 ("serial: sh-sci: add locking to console write
function to avoid SMP lockup") copied the strategy to avoid locking
problems in conjuncture with the console from the UART8250
driver. Instead using directly spin_{try}lock_irqsave(),
local_irq_save() followed by spin_{try}lock() was used. While this is
correct on mainline, for -rt it is a problem. spin_{try}lock() will
check if it is running in a valid context. Since the local_irq_save()
has already been executed, the context has changed and
spin_{try}lock() will complain. The reason why spin_{try}lock()
complains is that on -rt the spin locks are turned into mutexes and
therefore can sleep. Sleeping with interrupts disabled is not valid.

BUG: sleeping function called from invalid context at /home/wagi/work/rt/v4.4-cip-rt/kernel/locking/rtmutex.c:995
in_atomic(): 0, irqs_disabled(): 128, pid: 778, name: irq/76-eth0
CPU: 0 PID: 778 Comm: irq/76-eth0 Not tainted 4.4.126-test-cip22-rt14-00403-gcd03665c8318 hardkernel#12
Hardware name: Generic RZ/G1 (Flattened Device Tree)
Backtrace:
[<c00140a0>] (dump_backtrace) from [<c001424c>] (show_stack+0x18/0x1c)
 r7:c06b01f0 r6:60010193 r5:00000000 r4:c06b01f0
[<c0014234>] (show_stack) from [<c01d3c94>] (dump_stack+0x78/0x94)
[<c01d3c1c>] (dump_stack) from [<c004c134>] (___might_sleep+0x134/0x194)
 r7:60010113 r6:c06d3559 r5:00000000 r4:ffffe000
[<c004c000>] (___might_sleep) from [<c04ded60>] (rt_spin_lock+0x20/0x74)
 r5:c06f4d60 r4:c06f4d60
[<c04ded40>] (rt_spin_lock) from [<c02577e4>] (serial_console_write+0x100/0x118)
 r5:c06f4d60 r4:c06f4d60
[<c02576e4>] (serial_console_write) from [<c0061060>] (call_console_drivers.constprop.15+0x10c/0x124)
 r10:c06d2894 r9:c04e18b0 r8:00000028 r7:00000000 r6:c06d3559 r5:c06d2798
 r4:c06b9914 r3:c02576e4
[<c0060f54>] (call_console_drivers.constprop.15) from [<c0062984>] (console_unlock+0x32c/0x430)
 r10:c06d30d8 r9:00000028 r8:c06dd518 r7:00000005 r6:00000000 r5:c06d2798
 r4:c06d2798 r3:00000028
[<c0062658>] (console_unlock) from [<c0062e1c>] (vprintk_emit+0x394/0x4f0)
 r10:c06d2798 r9:c06d30ee r8:00000006 r7:00000005 r6:c06a78fc r5:00000027
 r4:00000003
[<c0062a88>] (vprintk_emit) from [<c0062fa0>] (vprintk+0x28/0x30)
 r10:c060bd46 r9:00001000 r8:c06b9a90 r7:c06b9a90 r6:c06b994c r5:c06b9a3c
 r4:c0062fa8
[<c0062f78>] (vprintk) from [<c0062fb8>] (vprintk_default+0x10/0x14)
[<c0062fa8>] (vprintk_default) from [<c009cd30>] (printk+0x78/0x84)
[<c009ccbc>] (printk) from [<c025afdc>] (credit_entropy_bits+0x17c/0x2cc)
 r3:00000001 r2:decade60 r1:c061a5ee r0:c061a523
 r4:00000006
[<c025ae60>] (credit_entropy_bits) from [<c025bf74>] (add_interrupt_randomness+0x160/0x178)
 r10:466e7196 r9:1f536000 r8:fffeef74 r7:00000000 r6:c06b9a60 r5:c06b9a3c
 r4:dfbcf680
[<c025be14>] (add_interrupt_randomness) from [<c006536c>] (irq_thread+0x1e8/0x248)
 r10:c006537c r9:c06cdf21 r8:c0064fcc r7:df791c24 r6:df791c00 r5:ffffe000
 r4:df525180
[<c0065184>] (irq_thread) from [<c003fba4>] (kthread+0x108/0x11c)
 r10:00000000 r9:00000000 r8:c0065184 r7:df791c00 r6:00000000 r5:df791d00
 r4:decac000
[<c003fa9c>] (kthread) from [<c00101b8>] (ret_from_fork+0x14/0x3c)
 r8:00000000 r7:00000000 r6:00000000 r5:c003fa9c r4:df791d00

Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Wagner <daniel.wagner@siemens.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dmole pushed a commit to Dmole/linux that referenced this pull request Jul 8, 2018
…s_replace()

commit bbb8c61 upstream.

When a chain is updated, a counter can be attached. if so,
the nft_counters_enabled should be increased.

test commands:

   %nft add table ip filter
   %nft add chain ip filter input { type filter hook input priority 4\; }
   %iptables-compat -Z input
   %nft delete chain ip filter input

we can see below messages.

[  286.443720] jump label: negative count!
[  286.448278] WARNING: CPU: 0 PID: 1459 at kernel/jump_label.c:197 __static_key_slow_dec_cpuslocked+0x6f/0xf0
[  286.449144] Modules linked in: nf_tables nfnetlink ip_tables x_tables
[  286.449144] CPU: 0 PID: 1459 Comm: nft Tainted: G        W         4.17.0-rc2+ hardkernel#12
[  286.449144] RIP: 0010:__static_key_slow_dec_cpuslocked+0x6f/0xf0
[  286.449144] RSP: 0018:ffff88010e5176f0 EFLAGS: 00010286
[  286.449144] RAX: 000000000000001b RBX: ffffffffc0179500 RCX: ffffffffb8a82522
[  286.449144] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88011b7e5eac
[  286.449144] RBP: 0000000000000000 R08: ffffed00236fce5c R09: ffffed00236fce5b
[  286.449144] R10: ffffffffc0179503 R11: ffffed00236fce5c R12: 0000000000000000
[  286.449144] R13: ffff88011a28e448 R14: ffff88011a28e470 R15: dffffc0000000000
[  286.449144] FS:  00007f0384328700(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000
[  286.449144] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  286.449144] CR2: 00007f038394bf10 CR3: 0000000104a86000 CR4: 00000000001006f0
[  286.449144] Call Trace:
[  286.449144]  static_key_slow_dec+0x6a/0x70
[  286.449144]  nf_tables_chain_destroy+0x19d/0x210 [nf_tables]
[  286.449144]  nf_tables_commit+0x1891/0x1c50 [nf_tables]
[  286.449144]  nfnetlink_rcv+0x1148/0x13d0 [nfnetlink]
[ ... ]

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Owersun pushed a commit to Owersun/linux-hardkernel that referenced this pull request Jul 14, 2018
…sion

commit 8afb1d2 upstream.

Commit 40f70c0 ("serial: sh-sci: add locking to console write
function to avoid SMP lockup") copied the strategy to avoid locking
problems in conjuncture with the console from the UART8250
driver. Instead using directly spin_{try}lock_irqsave(),
local_irq_save() followed by spin_{try}lock() was used. While this is
correct on mainline, for -rt it is a problem. spin_{try}lock() will
check if it is running in a valid context. Since the local_irq_save()
has already been executed, the context has changed and
spin_{try}lock() will complain. The reason why spin_{try}lock()
complains is that on -rt the spin locks are turned into mutexes and
therefore can sleep. Sleeping with interrupts disabled is not valid.

BUG: sleeping function called from invalid context at /home/wagi/work/rt/v4.4-cip-rt/kernel/locking/rtmutex.c:995
in_atomic(): 0, irqs_disabled(): 128, pid: 778, name: irq/76-eth0
CPU: 0 PID: 778 Comm: irq/76-eth0 Not tainted 4.4.126-test-cip22-rt14-00403-gcd03665c8318 hardkernel#12
Hardware name: Generic RZ/G1 (Flattened Device Tree)
Backtrace:
[<c00140a0>] (dump_backtrace) from [<c001424c>] (show_stack+0x18/0x1c)
 r7:c06b01f0 r6:60010193 r5:00000000 r4:c06b01f0
[<c0014234>] (show_stack) from [<c01d3c94>] (dump_stack+0x78/0x94)
[<c01d3c1c>] (dump_stack) from [<c004c134>] (___might_sleep+0x134/0x194)
 r7:60010113 r6:c06d3559 r5:00000000 r4:ffffe000
[<c004c000>] (___might_sleep) from [<c04ded60>] (rt_spin_lock+0x20/0x74)
 r5:c06f4d60 r4:c06f4d60
[<c04ded40>] (rt_spin_lock) from [<c02577e4>] (serial_console_write+0x100/0x118)
 r5:c06f4d60 r4:c06f4d60
[<c02576e4>] (serial_console_write) from [<c0061060>] (call_console_drivers.constprop.15+0x10c/0x124)
 r10:c06d2894 r9:c04e18b0 r8:00000028 r7:00000000 r6:c06d3559 r5:c06d2798
 r4:c06b9914 r3:c02576e4
[<c0060f54>] (call_console_drivers.constprop.15) from [<c0062984>] (console_unlock+0x32c/0x430)
 r10:c06d30d8 r9:00000028 r8:c06dd518 r7:00000005 r6:00000000 r5:c06d2798
 r4:c06d2798 r3:00000028
[<c0062658>] (console_unlock) from [<c0062e1c>] (vprintk_emit+0x394/0x4f0)
 r10:c06d2798 r9:c06d30ee r8:00000006 r7:00000005 r6:c06a78fc r5:00000027
 r4:00000003
[<c0062a88>] (vprintk_emit) from [<c0062fa0>] (vprintk+0x28/0x30)
 r10:c060bd46 r9:00001000 r8:c06b9a90 r7:c06b9a90 r6:c06b994c r5:c06b9a3c
 r4:c0062fa8
[<c0062f78>] (vprintk) from [<c0062fb8>] (vprintk_default+0x10/0x14)
[<c0062fa8>] (vprintk_default) from [<c009cd30>] (printk+0x78/0x84)
[<c009ccbc>] (printk) from [<c025afdc>] (credit_entropy_bits+0x17c/0x2cc)
 r3:00000001 r2:decade60 r1:c061a5ee r0:c061a523
 r4:00000006
[<c025ae60>] (credit_entropy_bits) from [<c025bf74>] (add_interrupt_randomness+0x160/0x178)
 r10:466e7196 r9:1f536000 r8:fffeef74 r7:00000000 r6:c06b9a60 r5:c06b9a3c
 r4:dfbcf680
[<c025be14>] (add_interrupt_randomness) from [<c006536c>] (irq_thread+0x1e8/0x248)
 r10:c006537c r9:c06cdf21 r8:c0064fcc r7:df791c24 r6:df791c00 r5:ffffe000
 r4:df525180
[<c0065184>] (irq_thread) from [<c003fba4>] (kthread+0x108/0x11c)
 r10:00000000 r9:00000000 r8:c0065184 r7:df791c00 r6:00000000 r5:df791d00
 r4:decac000
[<c003fa9c>] (kthread) from [<c00101b8>] (ret_from_fork+0x14/0x3c)
 r8:00000000 r7:00000000 r6:00000000 r5:c003fa9c r4:df791d00

Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Wagner <daniel.wagner@siemens.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
[dw: Backported to 4.4.]
Signed-off-by: Daniel Wagner <daniel.wagner@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mdrjr pushed a commit that referenced this pull request Sep 10, 2018
commit a5ba1d9 upstream.

We have reports of the following crash:

    PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0"
    #0 [ffff88085c6db710] machine_kexec at ffffffff81046239
    #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248
    #2 [ffff88085c6db830] oops_end at ffffffff81008ae7
    #3 [ffff88085c6db860] no_context at ffffffff81050b8f
    #4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75
    #5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83
    #6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e
    #7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c
    #8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122
    [exception RIP: uart_put_char+149]
    RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006
    RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081
    RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120
    RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320
    R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000
    R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
    #9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544
    #10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c
    #11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b
    #12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2
    #13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b
    #14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a
    #15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016
    #16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194
    #17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a
    #18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2
    #19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d
    #20 [ffff88085c6dbeb0] kthread at ffffffff81096384
    #21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f​

after slogging through some dissasembly:

ffffffff814b6720 <uart_put_char>:
ffffffff814b6720:	55                   	push   %rbp
ffffffff814b6721:	48 89 e5             	mov    %rsp,%rbp
ffffffff814b6724:	48 83 ec 20          	sub    $0x20,%rsp
ffffffff814b6728:	48 89 1c 24          	mov    %rbx,(%rsp)
ffffffff814b672c:	4c 89 64 24 08       	mov    %r12,0x8(%rsp)
ffffffff814b6731:	4c 89 6c 24 10       	mov    %r13,0x10(%rsp)
ffffffff814b6736:	4c 89 74 24 18       	mov    %r14,0x18(%rsp)
ffffffff814b673b:	e8 b0 8e 58 00       	callq  ffffffff81a3f5f0 <mcount>
ffffffff814b6740:	4c 8b a7 88 02 00 00 	mov    0x288(%rdi),%r12
ffffffff814b6747:	45 31 ed             	xor    %r13d,%r13d
ffffffff814b674a:	41 89 f6             	mov    %esi,%r14d
ffffffff814b674d:	49 83 bc 24 70 01 00 	cmpq   $0x0,0x170(%r12)
ffffffff814b6754:	00 00
ffffffff814b6756:	49 8b 9c 24 80 01 00 	mov    0x180(%r12),%rbx
ffffffff814b675d:	00
ffffffff814b675e:	74 2f                	je     ffffffff814b678f <uart_put_char+0x6f>
ffffffff814b6760:	48 89 df             	mov    %rbx,%rdi
ffffffff814b6763:	e8 a8 67 58 00       	callq  ffffffff81a3cf10 <_raw_spin_lock_irqsave>
ffffffff814b6768:	41 8b 8c 24 78 01 00 	mov    0x178(%r12),%ecx
ffffffff814b676f:	00
ffffffff814b6770:	89 ca                	mov    %ecx,%edx
ffffffff814b6772:	f7 d2                	not    %edx
ffffffff814b6774:	41 03 94 24 7c 01 00 	add    0x17c(%r12),%edx
ffffffff814b677b:	00
ffffffff814b677c:	81 e2 ff 0f 00 00    	and    $0xfff,%edx
ffffffff814b6782:	75 23                	jne    ffffffff814b67a7 <uart_put_char+0x87>
ffffffff814b6784:	48 89 c6             	mov    %rax,%rsi
ffffffff814b6787:	48 89 df             	mov    %rbx,%rdi
ffffffff814b678a:	e8 e1 64 58 00       	callq  ffffffff81a3cc70 <_raw_spin_unlock_irqrestore>
ffffffff814b678f:	44 89 e8             	mov    %r13d,%eax
ffffffff814b6792:	48 8b 1c 24          	mov    (%rsp),%rbx
ffffffff814b6796:	4c 8b 64 24 08       	mov    0x8(%rsp),%r12
ffffffff814b679b:	4c 8b 6c 24 10       	mov    0x10(%rsp),%r13
ffffffff814b67a0:	4c 8b 74 24 18       	mov    0x18(%rsp),%r14
ffffffff814b67a5:	c9                   	leaveq
ffffffff814b67a6:	c3                   	retq
ffffffff814b67a7:	49 8b 94 24 70 01 00 	mov    0x170(%r12),%rdx
ffffffff814b67ae:	00
ffffffff814b67af:	48 63 c9             	movslq %ecx,%rcx
ffffffff814b67b2:	41 b5 01             	mov    $0x1,%r13b
ffffffff814b67b5:	44 88 34 0a          	mov    %r14b,(%rdx,%rcx,1)
ffffffff814b67b9:	41 8b 94 24 78 01 00 	mov    0x178(%r12),%edx
ffffffff814b67c0:	00
ffffffff814b67c1:	83 c2 01             	add    $0x1,%edx
ffffffff814b67c4:	81 e2 ff 0f 00 00    	and    $0xfff,%edx
ffffffff814b67ca:	41 89 94 24 78 01 00 	mov    %edx,0x178(%r12)
ffffffff814b67d1:	00
ffffffff814b67d2:	eb b0                	jmp    ffffffff814b6784 <uart_put_char+0x64>
ffffffff814b67d4:	66 66 66 2e 0f 1f 84 	data32 data32 nopw %cs:0x0(%rax,%rax,1)
ffffffff814b67db:	00 00 00 00 00

for our build, this is crashing at:

    circ->buf[circ->head] = c;

Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf)
protected by the "per-port mutex", which based on uart_port_check() is
state->port.mutex. Indeed, the lock acquired in uart_put_char() is
uport->lock, i.e. not the same lock.

Anyway, since the lock is not acquired, if uart_shutdown() is called, the
last chunk of that function may release state->xmit.buf before its assigned
to null, and cause the race above.

To fix it, let's lock uport->lock when allocating/deallocating
state->xmit.buf in addition to the per-port mutex.

v2: switch to locking uport->lock on allocation/deallocation instead of
    locking the per-port mutex in uart_put_char. Note that since
    uport->lock is a spin lock, we have to switch the allocation to
    GFP_ATOMIC.
v3: move the allocation outside the lock, so we can switch back to
    GFP_KERNEL

Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2 participants