linux/drivers/usb
Jiri Slaby 19cd80a214 usblp: do not set TASK_INTERRUPTIBLE before lock
It is not permitted to set task state before lock. usblp_wwait sets
the state to TASK_INTERRUPTIBLE and calls mutex_lock_interruptible.
Upon return from that function, the state will be TASK_RUNNING again.

This is clearly a bug and a warning is generated with LOCKDEP too:
WARNING: CPU: 1 PID: 5109 at kernel/sched/core.c:7404 __might_sleep+0x7d/0x90()
do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffffa0c588d0>] usblp_wwait+0xa0/0x310 [usblp]
Modules linked in: ...
CPU: 1 PID: 5109 Comm: captmon Tainted: G        W       4.2.5-0.gef2823b-default #1
Hardware name: LENOVO 23252SG/23252SG, BIOS G2ET33WW (1.13 ) 07/24/2012
 ffffffff81a4edce ffff880236ec7ba8 ffffffff81716651 0000000000000000
 ffff880236ec7bf8 ffff880236ec7be8 ffffffff8106e146 0000000000000282
 ffffffff81a50119 000000000000028b 0000000000000000 ffff8802dab7c508
Call Trace:
...
 [<ffffffff8106e1c6>] warn_slowpath_fmt+0x46/0x50
 [<ffffffff8109a8bd>] __might_sleep+0x7d/0x90
 [<ffffffff8171b20f>] mutex_lock_interruptible_nested+0x2f/0x4b0
 [<ffffffffa0c588fc>] usblp_wwait+0xcc/0x310 [usblp]
 [<ffffffffa0c58bb2>] usblp_write+0x72/0x350 [usblp]
 [<ffffffff8121ed98>] __vfs_write+0x28/0xf0
...

Commit 7f477358e2 (usblp: Implement the
ENOSPC convention) moved the set prior locking. So move it back after
the lock.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Fixes: 7f477358e2 ("usblp: Implement the ENOSPC convention")
Acked-By: Pete Zaitcev <zaitcev@yahoo.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-19 16:31:42 -08:00
..
atm USB: atm: cxacru: fix blank line after declaration 2015-07-22 14:55:22 -07:00
c67x00 c67x00-hcd: use USB_DT_HUB 2015-04-03 19:03:16 +02:00
chipidea usb: chipidea: imx: fix a possible NULL dereference 2015-11-18 15:27:31 +08:00
class usblp: do not set TASK_INTERRUPTIBLE before lock 2015-11-19 16:31:42 -08:00
common usb: common: of_usb_get_dr_mode to usb_get_dr_mode 2015-09-27 10:54:31 -05:00
core usb: kconfig: fix warning of select USB_OTG 2015-11-19 16:31:42 -08:00
dwc2 usb: dwc2: host: Fix remote wakeup when not in DWC2_L2 2015-11-17 11:35:38 -06:00
dwc3 usb: dwc3: gadget: let us set lower max_speed 2015-11-17 11:35:48 -06:00
early
gadget usb: gadget: atmel_usba_udc: Expose correct device speed 2015-11-17 11:35:49 -06:00
host xhci: Fix a race in usb2 LPM resume, blocking U3 for usb2 devices 2015-11-18 09:24:41 -08:00
image scsi: Do not set cmd_per_lun to 1 in the host template 2015-05-31 18:06:28 -07:00
isp1760 usb: isp1760: udc: add ep capabilities support 2015-08-04 12:26:55 -05:00
misc usb: misc: usb3503: Use i2c_add_driver helper macro 2015-10-24 19:53:53 -07:00
mon USB: mon_stat.c: move assignment out of if () block 2015-05-10 16:01:11 +02:00
musb usb: musb: enable usb_dma parameter 2015-11-17 11:35:49 -06:00
phy usb: kconfig: fix warning of select USB_OTG 2015-11-19 16:31:42 -08:00
renesas_usbhs This is the big bulk of pin control changes for the 2015-11-02 12:30:39 -08:00
serial USB: option: add XS Stick W100-2 from 4G Systems 2015-11-19 16:31:42 -08:00
storage SCSI misc on 20151113 2015-11-13 20:35:54 -08:00
usbip usbip: vhci_hcd: at unlink, return -EIDRM if vhci_rx took the urb 2015-10-04 10:59:03 +01:00
wusbcore wusbcore: rh: use USB_DT_HUB 2015-04-03 19:03:15 +02:00
Kconfig usb: isp1760: Move driver from drivers/usb/host/ to drivers/usb/isp1760/ 2015-01-27 09:39:38 -06:00
Makefile usb-host: Remove fusbh200 driver 2015-10-16 23:44:33 -07:00
README
usb-skeleton.c

README

To understand all the Linux-USB framework, you'll use these resources:

    * This source code.  This is necessarily an evolving work, and
      includes kerneldoc that should help you get a current overview.
      ("make pdfdocs", and then look at "usb.pdf" for host side and
      "gadget.pdf" for peripheral side.)  Also, Documentation/usb has
      more information.

    * The USB 2.0 specification (from www.usb.org), with supplements
      such as those for USB OTG and the various device classes.
      The USB specification has a good overview chapter, and USB
      peripherals conform to the widely known "Chapter 9".

    * Chip specifications for USB controllers.  Examples include
      host controllers (on PCs, servers, and more); peripheral
      controllers (in devices with Linux firmware, like printers or
      cell phones); and hard-wired peripherals like Ethernet adapters.

    * Specifications for other protocols implemented by USB peripheral
      functions.  Some are vendor-specific; others are vendor-neutral
      but just standardized outside of the www.usb.org team.

Here is a list of what each subdirectory here is, and what is contained in
them.

core/		- This is for the core USB host code, including the
		  usbfs files and the hub class driver ("hub_wq").

host/		- This is for USB host controller drivers.  This
		  includes UHCI, OHCI, EHCI, and others that might
		  be used with more specialized "embedded" systems.

gadget/		- This is for USB peripheral controller drivers and
		  the various gadget drivers which talk to them.


Individual USB driver directories.  A new driver should be added to the
first subdirectory in the list below that it fits into.

image/		- This is for still image drivers, like scanners or
		  digital cameras.
../input/	- This is for any driver that uses the input subsystem,
		  like keyboard, mice, touchscreens, tablets, etc.
../media/	- This is for multimedia drivers, like video cameras,
		  radios, and any other drivers that talk to the v4l
		  subsystem.
../net/		- This is for network drivers.
serial/		- This is for USB to serial drivers.
storage/	- This is for USB mass-storage drivers.
class/		- This is for all USB device drivers that do not fit
		  into any of the above categories, and work for a range
		  of USB Class specified devices. 
misc/		- This is for all USB device drivers that do not fit
		  into any of the above categories.