Zhengjun Xing
7fc65d4c2b
xhci: Fix Kernel oops in xhci dbgtty
...
tty_unregister_driver may be called more than 1 time in some
hotplug cases,it will cause the kernel oops. This patch checked
dbc_tty_driver to make sure it is unregistered only 1 time.
[ 175.741404] BUG: unable to handle kernel NULL pointer dereference at 0000000000000034
[ 175.742309] IP: tty_unregister_driver+0x9/0x70
[ 175.743148] PGD 0 P4D 0
[ 175.743981] Oops: 0000 [#1 ] SMP PTI
[ 175.753904] RIP: 0010:tty_unregister_driver+0x9/0x70
[ 175.754817] RSP: 0018:ffffa8ff831d3bb0 EFLAGS: 00010246
[ 175.755753] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 175.756685] RDX: ffff92089c616000 RSI: ffffe64fe1b26080 RDI: 0000000000000000
[ 175.757608] RBP: ffff92086c988230 R08: 000000006c982701 R09: 00000001801e0016
[ 175.758533] R10: ffffa8ff831d3b48 R11: ffff92086c982100 R12: ffff92086c98827c
[ 175.759462] R13: ffff92086c988398 R14: 0000000000000060 R15: ffff92089c5e9b40
[ 175.760401] FS: 0000000000000000(0000) GS:ffff9208a0100000(0000) knlGS:0000000000000000
[ 175.761334] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 175.762270] CR2: 0000000000000034 CR3: 000000011800a003 CR4: 00000000003606e0
[ 175.763225] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 175.764164] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 175.765091] Call Trace:
[ 175.766014] xhci_dbc_tty_unregister_driver+0x11/0x30
[ 175.766960] xhci_dbc_exit+0x2a/0x40
[ 175.767889] xhci_stop+0x57/0x1c0
[ 175.768824] usb_remove_hcd+0x100/0x250
[ 175.769708] usb_hcd_pci_remove+0x68/0x130
[ 175.770574] pci_device_remove+0x3b/0xc0
[ 175.771435] device_release_driver_internal+0x157/0x230
[ 175.772343] pci_stop_bus_device+0x74/0xa0
[ 175.773205] pci_stop_bus_device+0x2b/0xa0
[ 175.774061] pci_stop_bus_device+0x2b/0xa0
[ 175.774907] pci_stop_bus_device+0x2b/0xa0
[ 175.775741] pci_stop_bus_device+0x2b/0xa0
[ 175.776618] pci_stop_bus_device+0x2b/0xa0
[ 175.777452] pci_stop_bus_device+0x2b/0xa0
[ 175.778273] pci_stop_bus_device+0x2b/0xa0
[ 175.779092] pci_stop_bus_device+0x2b/0xa0
[ 175.779908] pci_stop_bus_device+0x2b/0xa0
[ 175.780750] pci_stop_bus_device+0x2b/0xa0
[ 175.781543] pci_stop_and_remove_bus_device+0xe/0x20
[ 175.782338] pciehp_unconfigure_device+0xb8/0x160
[ 175.783128] pciehp_disable_slot+0x4f/0xd0
[ 175.783920] pciehp_power_thread+0x82/0xa0
[ 175.784766] process_one_work+0x147/0x3c0
[ 175.785564] worker_thread+0x4a/0x440
[ 175.786376] kthread+0xf8/0x130
[ 175.787174] ? rescuer_thread+0x360/0x360
[ 175.787964] ? kthread_associate_blkcg+0x90/0x90
[ 175.788798] ret_from_fork+0x35/0x40
Cc: <stable@vger.kernel.org> # 4.16
Fixes: dfba2174dc
2018-04-22 15:23:37 +02:00
Greg Kroah-Hartman
a8f25c36f7
Merge branch 4.16-rc6 into usb-next
...
We want the USB fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-20 09:56:08 +01:00
Dan Carpenter
29f653393e
usb: xhci: Clean up error code in xhci_dbc_tty_register_device()
...
tty_port_register_device() returns error pointers on error, never NULL.
The IS_ERR_OR_NULL() function returns either 1 or 0 so it means we
return 1 on error instead of a proper error code. The caller only
checks for zero vs non-zero so this doesn't affect runtime.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-16 15:40:18 +01:00
Lu Baolu
a098dc8b03
usb: xhci: dbc: Fix lockdep warning
...
The xHCI DbC implementation might enter a deadlock situation because
there is no sufficient protection against the shared data between
process and softirq contexts. This can lead to the following lockdep
warnings. This patch changes to use spin_{,un}lock_irq{save,restore}
to avoid potential deadlock.
[ 528.248084] ================================
[ 528.252914] WARNING: inconsistent lock state
[ 528.257756] 4.15.0-rc1+ #1630 Not tainted
[ 528.262305] --------------------------------
[ 528.267145] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[ 528.273953] ksoftirqd/1/17 [HC0[0]:SC1[1]:HE0:SE0] takes:
[ 528.280075] (&(&port->port_lock)->rlock){+.?.}, at: [<ffffffff815396a8>] dbc_rx_push+0x38/0x1c0
[ 528.290043] {SOFTIRQ-ON-W} state was registered at:
[ 528.295570] _raw_spin_lock+0x2f/0x40
[ 528.299818] dbc_write_complete+0x27/0xa0
[ 528.304458] xhci_dbc_giveback+0xd1/0x200
[ 528.309098] xhci_dbc_flush_endpoint_requests+0x50/0x70
[ 528.315116] xhci_dbc_handle_events+0x696/0x7b0
[ 528.320349] process_one_work+0x1ee/0x6e0
[ 528.324988] worker_thread+0x4a/0x430
[ 528.329236] kthread+0x13e/0x170
[ 528.332992] ret_from_fork+0x24/0x30
[ 528.337141] irq event stamp: 2861
[ 528.340897] hardirqs last enabled at (2860): [<ffffffff810674ea>] tasklet_action+0x6a/0x250
[ 528.350460] hardirqs last disabled at (2861): [<ffffffff817dc1ef>] _raw_spin_lock_irq+0xf/0x40
[ 528.360219] softirqs last enabled at (2852): [<ffffffff817e0e8c>] __do_softirq+0x3dc/0x4f9
[ 528.369683] softirqs last disabled at (2857): [<ffffffff8106805b>] run_ksoftirqd+0x1b/0x60
[ 528.379048]
[ 528.379048] other info that might help us debug this:
[ 528.386443] Possible unsafe locking scenario:
[ 528.386443]
[ 528.393150] CPU0
[ 528.395917] ----
[ 528.398687] lock(&(&port->port_lock)->rlock);
[ 528.403821] <Interrupt>
[ 528.406786] lock(&(&port->port_lock)->rlock);
[ 528.412116]
[ 528.412116] *** DEADLOCK ***
[ 528.412116]
[ 528.418825] no locks held by ksoftirqd/1/17.
[ 528.423662]
[ 528.423662] stack backtrace:
[ 528.428598] CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 4.15.0-rc1+ #1630
[ 528.436387] Call Trace:
[ 528.439158] dump_stack+0x5e/0x8e
[ 528.442914] print_usage_bug+0x1fc/0x220
[ 528.447357] mark_lock+0x4db/0x5a0
[ 528.451210] __lock_acquire+0x726/0x1130
[ 528.455655] ? __lock_acquire+0x557/0x1130
[ 528.460296] lock_acquire+0xa2/0x200
[ 528.464347] ? dbc_rx_push+0x38/0x1c0
[ 528.468496] _raw_spin_lock_irq+0x35/0x40
[ 528.473038] ? dbc_rx_push+0x38/0x1c0
[ 528.477186] dbc_rx_push+0x38/0x1c0
[ 528.481139] tasklet_action+0x1d2/0x250
[ 528.485483] __do_softirq+0x1dc/0x4f9
[ 528.489630] run_ksoftirqd+0x1b/0x60
[ 528.493682] smpboot_thread_fn+0x179/0x270
[ 528.498324] kthread+0x13e/0x170
[ 528.501981] ? sort_range+0x20/0x20
[ 528.505933] ? kthread_delayed_work_timer_fn+0x80/0x80
[ 528.511755] ret_from_fork+0x24/0x30
Fixes: dfba2174dc
2018-03-08 09:06:53 -08:00
Colin Ian King
66222f0d4b
usb: xhci: make function xhci_dbc_free_req static
...
Function xhci_dbc_free_req is local to the source and does not need to
be in global scope, so make it static.
Cleans up sparse warning:
symbol 'xhci_dbc_free_req' was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-12 13:16:07 +01:00
Lu Baolu
dfba2174dc
usb: xhci: Add DbC support in xHCI driver
...
xHCI compatible USB host controllers(i.e. super-speed USB3 controllers)
can be implemented with the Debug Capability(DbC). It presents a debug
device which is fully compliant with the USB framework and provides the
equivalent of a very high performance full-duplex serial link. The debug
capability operation model and registers interface are defined in 7.6.8
of the xHCI specification, revision 1.1.
The DbC debug device shares a root port with the xHCI host. By default,
the debug capability is disabled and the root port is assigned to xHCI.
When the DbC is enabled, the root port will be assigned to the DbC debug
device, and the xHCI sees nothing on this port. This implementation uses
a sysfs node named <dbc> under the xHCI device to manage the enabling
and disabling of the debug capability.
When the debug capability is enabled, it will present a debug device
through the debug port. This debug device is fully compliant with the
USB3 framework, and it can be enumerated by a debug host on the other
end of the USB link. As soon as the debug device is configured, a TTY
serial device named /dev/ttyDBC0 will be created.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-08 17:43:52 +01:00
