mainlining shenanigans
6c5c748908
ibmvnic_reset can create and schedule a reset work item from an IRQ context, so do not use a mutex, which can sleep. Convert the reset work item mutex to a spin lock. Locking debugger generated the trace output below. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908 in_atomic(): 1, irqs_disabled(): 1, pid: 120, name: kworker/8:1 4 locks held by kworker/8:1/120: #0: 0000000017c05720 ((wq_completion)"events"){+.+.}, at: process_one_work+0x188/0x710 #1: 00000000ace90706 ((linkwatch_work).work){+.+.}, at: process_one_work+0x188/0x710 #2: 000000007632871f (rtnl_mutex){+.+.}, at: rtnl_lock+0x30/0x50 #3: 00000000fc36813a (&(&crq->lock)->rlock){..-.}, at: ibmvnic_tasklet+0x88/0x2010 [ibmvnic] irq event stamp: 26293 hardirqs last enabled at (26292): [<c000000000122468>] tasklet_action_common.isra.12+0x78/0x1c0 hardirqs last disabled at (26293): [<c000000000befce8>] _raw_spin_lock_irqsave+0x48/0xf0 softirqs last enabled at (26288): [<c000000000a8ac78>] dev_deactivate_queue.constprop.28+0xc8/0x160 softirqs last disabled at (26289): [<c0000000000306e0>] call_do_softirq+0x14/0x24 CPU: 8 PID: 120 Comm: kworker/8:1 Kdump: loaded Not tainted 4.20.0-rc6 #6 Workqueue: events linkwatch_event Call Trace: [c0000003fffa7a50] [c000000000bc83e4] dump_stack+0xe8/0x164 (unreliable) [c0000003fffa7aa0] [c00000000015ba0c] ___might_sleep+0x2dc/0x320 [c0000003fffa7b20] [c000000000be960c] __mutex_lock+0x8c/0xb40 [c0000003fffa7c30] [d000000006202ac8] ibmvnic_reset+0x78/0x330 [ibmvnic] [c0000003fffa7cc0] [d0000000062097f4] ibmvnic_tasklet+0x1054/0x2010 [ibmvnic] [c0000003fffa7e00] [c0000000001224c8] tasklet_action_common.isra.12+0xd8/0x1c0 [c0000003fffa7e60] [c000000000bf1238] __do_softirq+0x1a8/0x64c [c0000003fffa7f90] [c0000000000306e0] call_do_softirq+0x14/0x24 [c0000003f3f87980] [c00000000001ba50] do_softirq_own_stack+0x60/0xb0 [c0000003f3f879c0] [c0000000001218a8] do_softirq+0xa8/0x100 [c0000003f3f879f0] [c000000000121a74] __local_bh_enable_ip+0x174/0x180 [c0000003f3f87a60] [c000000000bf003c] _raw_spin_unlock_bh+0x5c/0x80 [c0000003f3f87a90] [c000000000a8ac78] dev_deactivate_queue.constprop.28+0xc8/0x160 [c0000003f3f87ad0] [c000000000a8c8b0] dev_deactivate_many+0xd0/0x520 [c0000003f3f87b70] [c000000000a8cd40] dev_deactivate+0x40/0x60 [c0000003f3f87ba0] [c000000000a5e0c4] linkwatch_do_dev+0x74/0xd0 [c0000003f3f87bd0] [c000000000a5e694] __linkwatch_run_queue+0x1a4/0x1f0 [c0000003f3f87c30] [c000000000a5e728] linkwatch_event+0x48/0x60 [c0000003f3f87c50] [c0000000001444e8] process_one_work+0x238/0x710 [c0000003f3f87d20] [c000000000144a48] worker_thread+0x88/0x4e0 [c0000003f3f87db0] [c00000000014e3a8] kthread+0x178/0x1c0 [c0000003f3f87e20] [c00000000000bfd0] ret_from_kernel_thread+0x5c/0x6c Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
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| README | ||
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.