On Thu, Apr 20, 2017 at 02:00:27PM -0400, Nate Dailey wrote: > A trip through usb_hcd_pci_remove produces: > > BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:993 > in_atomic(): 0, irqs_disabled(): 1, pid: 4752, name: bash > INFO: lockdep is turned off. > irq event stamp: 0 > hardirqs last enabled at (0): [< (null)>] (null) > hardirqs last disabled at (0): [<ffffffff8108da9d>] copy_process.part.36+0x64d/0x2380 > softirqs last enabled at (0): [<ffffffff8108da9d>] copy_process.part.36+0x64d/0x2380 > softirqs last disabled at (0): [< (null)>] (null) > CPU: 1 PID: 4752 Comm: bash Tainted: G W I 4.9.0debug-rt16+ #2 > Hardware name: Stratus ftServer 2700/G7LAY, BIOS BIOS Version 6.3:58 09/18/2014 > ffffc90006e5fbd0 ffffffff813d243a ffff88016ac0b240 0000000000001290 > ffffc90006e5fbf8 ffffffff810c6907 ffff8801682f45d0 ffff8801682f1000 > ffff8801682f45d0 ffffc90006e5fc18 ffffffff817dee44 ffff88016b2aee18 > Call Trace: > [<ffffffff813d243a>] dump_stack+0x99/0xcf > [<ffffffff810c6907>] ___might_sleep+0x137/0x210 > [<ffffffff817dee44>] rt_spin_lock+0x24/0x60 > [<ffffffff815b526f>] ehci_irq+0x2f/0x400 > [<ffffffff814226b9>] ? pci_bus_read_config_word+0x99/0xb0 > [<ffffffff81592d66>] usb_hcd_irq+0x26/0x40 > [<ffffffff815a7a90>] usb_hcd_pci_remove+0x50/0x170 > [<ffffffff815b933a>] ehci_pci_remove+0x1a/0x20 > [<ffffffff8142fc39>] pci_device_remove+0x39/0xc0 > [<ffffffff8152c4da>] __device_release_driver+0x9a/0x150 > [<ffffffff8152c5b3>] device_release_driver+0x23/0x30 > [<ffffffff81427f6c>] pci_stop_bus_device+0x8c/0xa0 > [<ffffffff8142808a>] pci_stop_and_remove_bus_device_locked+0x1a/0x30 > [<ffffffff8143182c>] remove_store+0x7c/0x90 > [<ffffffff81526508>] dev_attr_store+0x18/0x30 > [<ffffffff81313444>] sysfs_kf_write+0x44/0x60 > [<ffffffff81312d7c>] kernfs_fop_write+0x13c/0x1d0 > [<ffffffff81279bb7>] __vfs_write+0x37/0x160 > [<ffffffff81118c82>] ? rcu_sync_lockdep_assert+0x12/0x60 > [<ffffffff8127e3c6>] ? __sb_start_write+0x176/0x260 > [<ffffffff8127a3f4>] ? vfs_write+0x184/0x1b0 > [<ffffffff8127a325>] vfs_write+0xb5/0x1b0 > [<ffffffff810025e0>] ? syscall_trace_enter+0x1d0/0x380 > [<ffffffff8127b7e8>] SyS_write+0x58/0xc0 > [<ffffffff81002d0a>] do_syscall_64+0x7a/0x230 > [<ffffffff817df6c9>] entry_SYSCALL64_slow_path+0x25/0x25 > > Repro via something like: > > > echo 1 > /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:01.0/0000:3d:00.0/0000:3e:01.0/0000:66:00.0/remove > > Switching usb_hcd_pci_remove to use _nort variants prevents the BUG. > > Signed-off-by: Nate Dailey <nate.dailey@xxxxxxxxxxx> > --- Acked-by: Luis Claudio R. Goncalves <lgoncalv@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html