mirror of https://gitee.com/openkylin/linux.git
942e443127
DEBUG_KOBJECT_RELEASE helps to find the issue attached below. After some investigation, it seems the reason is: The mod->mkobj.kobj(ffffffffa01600d0 below) is freed together with mod itself in free_module(). However, its children still hold references to it, as the delay caused by DEBUG_KOBJECT_RELEASE. So when the child(holders below) tries to decrease the reference count to its parent in kobject_del(), BUG happens as it tries to access already freed memory. This patch tries to fix it by waiting for the mod->mkobj.kobj to be really released in the module removing process (and some error code paths). [ 1844.175287] kobject: 'holders' (ffff88007c1f1600): kobject_release, parent ffffffffa01600d0 (delayed) [ 1844.178991] kobject: 'notes' (ffff8800370b2a00): kobject_release, parent ffffffffa01600d0 (delayed) [ 1845.180118] kobject: 'holders' (ffff88007c1f1600): kobject_cleanup, parent ffffffffa01600d0 [ 1845.182130] kobject: 'holders' (ffff88007c1f1600): auto cleanup kobject_del [ 1845.184120] BUG: unable to handle kernel paging request at ffffffffa01601d0 [ 1845.185026] IP: [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] PGD 1a13067 PUD 1a14063 PMD 7bd30067 PTE 0 [ 1845.185026] Oops: 0000 [#1] PREEMPT [ 1845.185026] Modules linked in: xfs libcrc32c [last unloaded: kprobe_example] [ 1845.185026] CPU: 0 PID: 18 Comm: kworker/0:1 Tainted: G O 3.11.0-rc6-next-20130819+ #1 [ 1845.185026] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 1845.185026] Workqueue: events kobject_delayed_cleanup [ 1845.185026] task: ffff88007ca51f00 ti: ffff88007ca5c000 task.ti: ffff88007ca5c000 [ 1845.185026] RIP: 0010:[<ffffffff812cda81>] [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] RSP: 0018:ffff88007ca5dd08 EFLAGS: 00010282 [ 1845.185026] RAX: 0000000000002000 RBX: ffffffffa01600d0 RCX: ffffffff8177d638 [ 1845.185026] RDX: ffff88007ca5dc18 RSI: 0000000000000000 RDI: ffffffffa01600d0 [ 1845.185026] RBP: ffff88007ca5dd18 R08: ffffffff824e9810 R09: ffffffffffffffff [ 1845.185026] R10: ffff8800ffffffff R11: dead4ead00000001 R12: ffffffff81a95040 [ 1845.185026] R13: ffff88007b27a960 R14: ffff88007c1f1600 R15: 0000000000000000 [ 1845.185026] FS: 0000000000000000(0000) GS:ffffffff81a23000(0000) knlGS:0000000000000000 [ 1845.185026] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1845.185026] CR2: ffffffffa01601d0 CR3: 0000000037207000 CR4: 00000000000006b0 [ 1845.185026] Stack: [ 1845.185026] ffff88007c1f1600 ffff88007c1f1600 ffff88007ca5dd38 ffffffff812cdb7e [ 1845.185026] 0000000000000000 ffff88007c1f1640 ffff88007ca5dd68 ffffffff812cdbfe [ 1845.185026] ffff88007c974800 ffff88007c1f1640 ffff88007ff61a00 0000000000000000 [ 1845.185026] Call Trace: [ 1845.185026] [<ffffffff812cdb7e>] kobject_del+0x2e/0x40 [ 1845.185026] [<ffffffff812cdbfe>] kobject_delayed_cleanup+0x6e/0x1d0 [ 1845.185026] [<ffffffff81063a45>] process_one_work+0x1e5/0x670 [ 1845.185026] [<ffffffff810639e3>] ? process_one_work+0x183/0x670 [ 1845.185026] [<ffffffff810642b3>] worker_thread+0x113/0x370 [ 1845.185026] [<ffffffff810641a0>] ? rescuer_thread+0x290/0x290 [ 1845.185026] [<ffffffff8106bfba>] kthread+0xda/0xe0 [ 1845.185026] [<ffffffff814ff0f0>] ? _raw_spin_unlock_irq+0x30/0x60 [ 1845.185026] [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130 [ 1845.185026] [<ffffffff8150751a>] ret_from_fork+0x7a/0xb0 [ 1845.185026] [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130 [ 1845.185026] Code: 81 48 c7 c7 28 95 ad 81 31 c0 e8 9b da 01 00 e9 4f ff ff ff 66 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 85 ff 74 1d <f6> 87 00 01 00 00 01 74 1e 48 8d 7b 38 83 6b 38 01 0f 94 c0 84 [ 1845.185026] RIP [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] RSP <ffff88007ca5dd08> [ 1845.185026] CR2: ffffffffa01601d0 [ 1845.185026] ---[ end trace 49a70afd109f5653 ]--- Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> |
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| .. | ||
| cpu | ||
| debug | ||
| events | ||
| gcov | ||
| irq | ||
| power | ||
| sched | ||
| time | ||
| trace | ||
| .gitignore | ||
| Kconfig.freezer | ||
| Kconfig.hz | ||
| Kconfig.locks | ||
| Kconfig.preempt | ||
| Makefile | ||
| acct.c | ||
| async.c | ||
| audit.c | ||
| audit.h | ||
| audit_tree.c | ||
| audit_watch.c | ||
| auditfilter.c | ||
| auditsc.c | ||
| backtracetest.c | ||
| bounds.c | ||
| capability.c | ||
| cgroup.c | ||
| cgroup_freezer.c | ||
| compat.c | ||
| configs.c | ||
| context_tracking.c | ||
| cpu.c | ||
| cpu_pm.c | ||
| cpuset.c | ||
| crash_dump.c | ||
| cred.c | ||
| delayacct.c | ||
| dma.c | ||
| elfcore.c | ||
| exec_domain.c | ||
| exit.c | ||
| extable.c | ||
| fork.c | ||
| freezer.c | ||
| futex.c | ||
| futex_compat.c | ||
| groups.c | ||
| hrtimer.c | ||
| hung_task.c | ||
| irq_work.c | ||
| itimer.c | ||
| jump_label.c | ||
| kallsyms.c | ||
| kcmp.c | ||
| kexec.c | ||
| kmod.c | ||
| kprobes.c | ||
| ksysfs.c | ||
| kthread.c | ||
| latencytop.c | ||
| lglock.c | ||
| lockdep.c | ||
| lockdep_internals.h | ||
| lockdep_proc.c | ||
| lockdep_states.h | ||
| modsign_certificate.S | ||
| modsign_pubkey.c | ||
| module-internal.h | ||
| module.c | ||
| module_signing.c | ||
| mutex-debug.c | ||
| mutex-debug.h | ||
| mutex.c | ||
| mutex.h | ||
| notifier.c | ||
| nsproxy.c | ||
| padata.c | ||
| panic.c | ||
| params.c | ||
| pid.c | ||
| pid_namespace.c | ||
| posix-cpu-timers.c | ||
| posix-timers.c | ||
| printk.c | ||
| profile.c | ||
| ptrace.c | ||
| range.c | ||
| rcu.h | ||
| rcupdate.c | ||
| rcutiny.c | ||
| rcutiny_plugin.h | ||
| rcutorture.c | ||
| rcutree.c | ||
| rcutree.h | ||
| rcutree_plugin.h | ||
| rcutree_trace.c | ||
| reboot.c | ||
| relay.c | ||
| res_counter.c | ||
| resource.c | ||
| rtmutex-debug.c | ||
| rtmutex-debug.h | ||
| rtmutex-tester.c | ||
| rtmutex.c | ||
| rtmutex.h | ||
| rtmutex_common.h | ||
| rwsem.c | ||
| seccomp.c | ||
| semaphore.c | ||
| signal.c | ||
| smp.c | ||
| smpboot.c | ||
| smpboot.h | ||
| softirq.c | ||
| spinlock.c | ||
| srcu.c | ||
| stacktrace.c | ||
| stop_machine.c | ||
| sys.c | ||
| sys_ni.c | ||
| sysctl.c | ||
| sysctl_binary.c | ||
| task_work.c | ||
| taskstats.c | ||
| test_kprobes.c | ||
| time.c | ||
| timeconst.bc | ||
| timer.c | ||
| tracepoint.c | ||
| tsacct.c | ||
| uid16.c | ||
| up.c | ||
| user-return-notifier.c | ||
| user.c | ||
| user_namespace.c | ||
| utsname.c | ||
| utsname_sysctl.c | ||
| wait.c | ||
| watchdog.c | ||
| workqueue.c | ||
| workqueue_internal.h | ||