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Linux kernel source tree
e64e469b9a
Heiner reported a lockdep splat [1]
This is caused by attempting GFP_KERNEL allocation while RCU lock is
held and BH blocked.
We believe that addrconf_verify_rtnl() could run for a long period,
so instead of using GFP_ATOMIC here as Ido suggested, we should break
the critical section and restart it after the allocation.
[1]
[86220.125562] =============================
[86220.125586] WARNING: suspicious RCU usage
[86220.125612] 4.15.0-rc7-next-20180110+ #7 Not tainted
[86220.125641] -----------------------------
[86220.125666] kernel/sched/core.c:6026 Illegal context switch in RCU-bh read-side critical section!
[86220.125711]
other info that might help us debug this:
[86220.125755]
rcu_scheduler_active = 2, debug_locks = 1
[86220.125792] 4 locks held by kworker/0:2/1003:
[86220.125817] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.125895] #1: ((addr_chk_work).work){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.125959] #2: (rtnl_mutex){+.+.}, at: [<00000000b06d9510>] rtnl_lock+0x12/0x20
[86220.126017] #3: (rcu_read_lock_bh){....}, at: [<00000000aef52299>] addrconf_verify_rtnl+0x1e/0x510 [ipv6]
[86220.126111]
stack backtrace:
[86220.126142] CPU: 0 PID: 1003 Comm: kworker/0:2 Not tainted 4.15.0-rc7-next-20180110+ #7
[86220.126185] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015
[86220.126250] Workqueue: ipv6_addrconf addrconf_verify_work [ipv6]
[86220.126288] Call Trace:
[86220.126312] dump_stack+0x70/0x9e
[86220.126337] lockdep_rcu_suspicious+0xce/0xf0
[86220.126365] ___might_sleep+0x1d3/0x240
[86220.126390] __might_sleep+0x45/0x80
[86220.126416] kmem_cache_alloc_trace+0x53/0x250
[86220.126458] ? ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.126498] ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.126538] ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.126580] ? ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.126623] addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.126664] ? addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.126708] addrconf_verify_work+0xe/0x20 [ipv6]
[86220.126738] process_one_work+0x258/0x680
[86220.126765] worker_thread+0x35/0x3f0
[86220.126790] kthread+0x124/0x140
[86220.126813] ? process_one_work+0x680/0x680
[86220.126839] ? kthread_create_worker_on_cpu+0x40/0x40
[86220.126869] ? umh_complete+0x40/0x40
[86220.126893] ? call_usermodehelper_exec_async+0x12a/0x160
[86220.126926] ret_from_fork+0x4b/0x60
[86220.126999] BUG: sleeping function called from invalid context at mm/slab.h:420
[86220.127041] in_atomic(): 1, irqs_disabled(): 0, pid: 1003, name: kworker/0:2
[86220.127082] 4 locks held by kworker/0:2/1003:
[86220.127107] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.127179] #1: ((addr_chk_work).work){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.127242] #2: (rtnl_mutex){+.+.}, at: [<00000000b06d9510>] rtnl_lock+0x12/0x20
[86220.127300] #3: (rcu_read_lock_bh){....}, at: [<00000000aef52299>] addrconf_verify_rtnl+0x1e/0x510 [ipv6]
[86220.127414] CPU: 0 PID: 1003 Comm: kworker/0:2 Not tainted 4.15.0-rc7-next-20180110+ #7
[86220.127463] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015
[86220.127528] Workqueue: ipv6_addrconf addrconf_verify_work [ipv6]
[86220.127568] Call Trace:
[86220.127591] dump_stack+0x70/0x9e
[86220.127616] ___might_sleep+0x14d/0x240
[86220.127644] __might_sleep+0x45/0x80
[86220.127672] kmem_cache_alloc_trace+0x53/0x250
[86220.127717] ? ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.127762] ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.127807] ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.127854] ? ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.127903] addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.127950] ? addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.127998] addrconf_verify_work+0xe/0x20 [ipv6]
[86220.128032] process_one_work+0x258/0x680
[86220.128063] worker_thread+0x35/0x3f0
[86220.128091] kthread+0x124/0x140
[86220.128117] ? process_one_work+0x680/0x680
[86220.128146] ? kthread_create_worker_on_cpu+0x40/0x40
[86220.128180] ? umh_complete+0x40/0x40
[86220.128207] ? call_usermodehelper_exec_async+0x12a/0x160
[86220.128243] ret_from_fork+0x4b/0x60
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.