0c9e8b3cad
stub_probe() and stub_disconnect() call functions which could call sleeping function in invalid context whil holding busid_lock. Fix the problem by refining the lock holds to short critical sections to change the busid_priv fields. This fix restructures the code to limit the lock holds in stub_probe() and stub_disconnect(). stub_probe(): [15217.927028] BUG: sleeping function called from invalid context at mm/slab.h:418 [15217.927038] in_atomic(): 1, irqs_disabled(): 0, pid: 29087, name: usbip [15217.927044] 5 locks held by usbip/29087: [15217.927047] #0: 0000000091647f28 (sb_writers#6){....}, at: vfs_write+0x191/0x1c0 [15217.927062] #1: 000000008f9ba75b (&of->mutex){....}, at: kernfs_fop_write+0xf7/0x1b0 [15217.927072] #2: 00000000872e5b4b (&dev->mutex){....}, at: __device_driver_lock+0x3b/0x50 [15217.927082] #3: 00000000e74ececc (&dev->mutex){....}, at: __device_driver_lock+0x46/0x50 [15217.927090] #4: 00000000b20abbe0 (&(&busid_table[i].busid_lock)->rlock){....}, at: get_busid_priv+0x48/0x60 [usbip_host] [15217.927103] CPU: 3 PID: 29087 Comm: usbip Tainted: G W 5.1.0-rc6+ #40 [15217.927106] Hardware name: Dell Inc. OptiPlex 790/0HY9JP, BIOS A18 09/24/2013 [15217.927109] Call Trace: [15217.927118] dump_stack+0x63/0x85 [15217.927127] ___might_sleep+0xff/0x120 [15217.927133] __might_sleep+0x4a/0x80 [15217.927143] kmem_cache_alloc_trace+0x1aa/0x210 [15217.927156] stub_probe+0xe8/0x440 [usbip_host] [15217.927171] usb_probe_device+0x34/0x70 stub_disconnect(): [15279.182478] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908 [15279.182487] in_atomic(): 1, irqs_disabled(): 0, pid: 29114, name: usbip [15279.182492] 5 locks held by usbip/29114: [15279.182494] #0: 0000000091647f28 (sb_writers#6){....}, at: vfs_write+0x191/0x1c0 [15279.182506] #1: 00000000702cf0f3 (&of->mutex){....}, at: kernfs_fop_write+0xf7/0x1b0 [15279.182514] #2: 00000000872e5b4b (&dev->mutex){....}, at: __device_driver_lock+0x3b/0x50 [15279.182522] #3: 00000000e74ececc (&dev->mutex){....}, at: __device_driver_lock+0x46/0x50 [15279.182529] #4: 00000000b20abbe0 (&(&busid_table[i].busid_lock)->rlock){....}, at: get_busid_priv+0x48/0x60 [usbip_host] [15279.182541] CPU: 0 PID: 29114 Comm: usbip Tainted: G W 5.1.0-rc6+ #40 [15279.182543] Hardware name: Dell Inc. OptiPlex 790/0HY9JP, BIOS A18 09/24/2013 [15279.182546] Call Trace: [15279.182554] dump_stack+0x63/0x85 [15279.182561] ___might_sleep+0xff/0x120 [15279.182566] __might_sleep+0x4a/0x80 [15279.182574] __mutex_lock+0x55/0x950 [15279.182582] ? get_busid_priv+0x48/0x60 [usbip_host] [15279.182587] ? reacquire_held_locks+0xec/0x1a0 [15279.182591] ? get_busid_priv+0x48/0x60 [usbip_host] [15279.182597] ? find_held_lock+0x94/0xa0 [15279.182609] mutex_lock_nested+0x1b/0x20 [15279.182614] ? mutex_lock_nested+0x1b/0x20 [15279.182618] kernfs_remove_by_name_ns+0x2a/0x90 [15279.182625] sysfs_remove_file_ns+0x15/0x20 [15279.182629] device_remove_file+0x19/0x20 [15279.182634] stub_disconnect+0x6d/0x180 [usbip_host] [15279.182643] usb_unbind_device+0x27/0x60 Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.