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https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git
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| Filename | Latest commit message | Latest commit date |
|---|---|---|
7487017282
The problem is found during iwlagn driver testing on v2.6.27-rc4-176-gb8e6c91 kernel, but it turns out to be a lockdep bug. In our testing, we frequently load and unload the iwlagn driver (>50 times). Then the MAX_STACK_TRACE_ENTRIES is reached (expected behaviour?). The error message with the call trace is as below. BUG: MAX_STACK_TRACE_ENTRIES too low! turning off the locking correctness validator. Pid: 4895, comm: iwlagn Not tainted 2.6.27-rc4 #13 Call Trace: [<ffffffff81014aa1>] save_stack_trace+0x22/0x3e [<ffffffff8105390a>] save_trace+0x8b/0x91 [<ffffffff81054e60>] mark_lock+0x1b0/0x8fa [<ffffffff81056f71>] __lock_acquire+0x5b9/0x716 [<ffffffffa00d818a>] ieee80211_sta_work+0x0/0x6ea [mac80211] [<ffffffff81057120>] lock_acquire+0x52/0x6b [<ffffffff81045f0e>] run_workqueue+0x97/0x1ed [<ffffffff81045f5e>] run_workqueue+0xe7/0x1ed [<ffffffff81045f0e>] run_workqueue+0x97/0x1ed [<ffffffff81046ae4>] worker_thread+0xd8/0xe3 [<ffffffff81049503>] autoremove_wake_function+0x0/0x2e [<ffffffff81046a0c>] worker_thread+0x0/0xe3 [<ffffffff810493ec>] kthread+0x47/0x73 [<ffffffff8128e3ab>] trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff8100cea9>] child_rip+0xa/0x11 [<ffffffff8100c4df>] restore_args+0x0/0x30 [<ffffffff810316e1>] finish_task_switch+0x0/0xcc [<ffffffff810493a5>] kthread+0x0/0x73 [<ffffffff8100ce9f>] child_rip+0x0/0x11 Although the above is harmless, when the ilwagn module is removed later lockdep will trigger a kernel oops as below. BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: [<ffffffff810531e1>] zap_class+0x24/0x82 PGD 73128067 PUD 7448c067 PMD 0 Oops: 0002 [1] SMP CPU 0 Modules linked in: rfcomm l2cap bluetooth autofs4 sunrpc nf_conntrack_ipv6 xt_state nf_conntrack xt_tcpudp ip6t_ipv6header ip6t_REJECT ip6table_filter ip6_tables x_tables ipv6 cpufreq_ondemand acpi_cpufreq dm_mirror dm_log dm_multipath dm_mod snd_hda_intel sr_mod snd_seq_dummy snd_seq_oss snd_seq_midi_event battery snd_seq snd_seq_device cdrom button snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd_page_alloc e1000e snd_hwdep sg iTCO_wdt iTCO_vendor_support ac pcspkr i2c_i801 i2c_core snd soundcore video output ata_piix ata_generic libata sd_mod scsi_mod ext3 jbd mbcache uhci_hcd ohci_hcd ehci_hcd [last unloaded: mac80211] Pid: 4941, comm: modprobe Not tainted 2.6.27-rc4 #10 RIP: 0010:[<ffffffff810531e1>] [<ffffffff810531e1>] zap_class+0x24/0x82 RSP: 0000:ffff88007bcb3eb0 EFLAGS: 00010046 RAX: 0000000000068ee8 RBX: ffffffff8192a0a0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000001dfb RDI: ffffffff816e70b0 RBP: ffffffffa00cd000 R08: ffffffff816818f8 R09: ffff88007c923558 R10: ffffe20002ad2408 R11: ffffffff811028ec R12: ffffffff8192a0a0 R13: 000000000002bd90 R14: 0000000000000000 R15: 0000000000000296 FS: 00007f9d1cee56f0(0000) GS:ffffffff814a58c0(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000008 CR3: 0000000073047000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process modprobe (pid: 4941, threadinfo ffff88007bcb2000, task ffff8800758d1fc0) Stack: ffffffff81057376 0000000000000000 ffffffffa00f7b00 0000000000000000 0000000000000080 0000000000618278 00007fff24f16720 0000000000000000 ffffffff8105d37a ffffffffa00f7b00 ffffffff8105d591 313132303863616d Call Trace: [<ffffffff81057376>] ? lockdep_free_key_range+0x61/0xf5 [<ffffffff8105d37a>] ? free_module+0xd4/0xe4 [<ffffffff8105d591>] ? sys_delete_module+0x1de/0x1f9 [<ffffffff8106dbfa>] ? audit_syscall_entry+0x12d/0x160 [<ffffffff8100be2b>] ? system_call_fastpath+0x16/0x1b Code: b2 00 01 00 00 00 c3 31 f6 49 c7 c0 10 8a 61 81 eb 32 49 39 38 75 26 48 98 48 6b c0 38 48 8b 90 08 8a 61 81 48 8b 88 00 8a 61 81 <48> 89 51 08 48 89 0a 48 c7 80 08 8a 61 81 00 02 20 00 48 ff c6 RIP [<ffffffff810531e1>] zap_class+0x24/0x82 RSP <ffff88007bcb3eb0> CR2: 0000000000000008 ---[ end trace a1297e0c4abb0f2e ]--- The root cause for this oops is in add_lock_to_list() when save_trace() fails due to MAX_STACK_TRACE_ENTRIES is reached, entry->class is assigned but entry is never added into any lock list. This makes the list_del_rcu() in zap_class() oops later when the module is unloaded. This patch fixes the problem by assigning entry->class after save_trace() returns success. Signed-off-by: Zhu Yi <yi.zhu@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> |
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| irq | ||
| power | ||
| time | ||
| trace | ||
| .gitignore | ||
| acct.c | ||
| audit.c | ||
| audit.h | ||
| audit_tree.c | ||
| auditfilter.c | ||
| auditsc.c | ||
| backtracetest.c | ||
| bounds.c | ||
| capability.c | ||
| cgroup.c | ||
| cgroup_debug.c | ||
| compat.c | ||
| configs.c | ||
| cpu.c | ||
| cpuset.c | ||
| delayacct.c | ||
| dma-coherent.c | ||
| dma.c | ||
| exec_domain.c | ||
| exit.c | ||
| extable.c | ||
| fork.c | ||
| futex.c | ||
| futex_compat.c | ||
| hrtimer.c | ||
| itimer.c | ||
| kallsyms.c | ||
| Kconfig.hz | ||
| Kconfig.preempt | ||
| kexec.c | ||
| kfifo.c | ||
| kgdb.c | ||
| kmod.c | ||
| kprobes.c | ||
| ksysfs.c | ||
| kthread.c | ||
| latencytop.c | ||
| lockdep.c | ||
| lockdep_internals.h | ||
| lockdep_proc.c | ||
| Makefile | ||
| marker.c | ||
| module.c | ||
| mutex-debug.c | ||
| mutex-debug.h | ||
| mutex.c | ||
| mutex.h | ||
| notifier.c | ||
| ns_cgroup.c | ||
| nsproxy.c | ||
| panic.c | ||
| params.c | ||
| pid.c | ||
| pid_namespace.c | ||
| pm_qos_params.c | ||
| posix-cpu-timers.c | ||
| posix-timers.c | ||
| printk.c | ||
| profile.c | ||
| ptrace.c | ||
| rcuclassic.c | ||
| rcupdate.c | ||
| rcupreempt.c | ||
| rcupreempt_trace.c | ||
| rcutorture.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 | ||
| sched.c | ||
| sched_clock.c | ||
| sched_cpupri.c | ||
| sched_cpupri.h | ||
| sched_debug.c | ||
| sched_fair.c | ||
| sched_features.h | ||
| sched_idletask.c | ||
| sched_rt.c | ||
| sched_stats.h | ||
| seccomp.c | ||
| semaphore.c | ||
| signal.c | ||
| smp.c | ||
| softirq.c | ||
| softlockup.c | ||
| spinlock.c | ||
| srcu.c | ||
| stacktrace.c | ||
| stop_machine.c | ||
| sys.c | ||
| sys_ni.c | ||
| sysctl.c | ||
| sysctl_check.c | ||
| taskstats.c | ||
| test_kprobes.c | ||
| time.c | ||
| timeconst.pl | ||
| timer.c | ||
| tsacct.c | ||
| uid16.c | ||
| user.c | ||
| user_namespace.c | ||
| utsname.c | ||
| utsname_sysctl.c | ||
| wait.c | ||
| workqueue.c | ||