Greetings, FYI, an old WARNING that still exists in upstream and linux-next. Note that the second "NULL pointer dereference" bug has been fixed in latest upstream and linux-next. [ 1.717904] Testing tracer wakeup_rt: ret = 0 [ 1.960950] PASSED [ 1.990036] Testing tracer branch: [ 2.123408] ------------[ cut here ]------------ [ 2.124080] WARNING: at /c/kernel-tests/src/tip/kernel/lockdep.c:3539 check_flags.part.41+0xc0/0x200() [ 2.125245] DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled) [ 2.125984] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.10.0-rc1-00058-g57b8c53 #16 [ 2.126666] 0000000000000009 ffff88000dc03cf8 ffffffff81aef1b9 ffff88000dc03d30 [ 2.126666] ffffffff810c0113 ffff88000d2e1fd8 0000000000000000 0000000000000000 [ 2.126666] 0000000000000002 0000000000000000 ffff88000dc03d90 ffffffff810c019c [ 2.126666] Call Trace: [ 2.126666] [] dump_stack+0x19/0x1b [ 2.126666] [] warn_slowpath_common+0x73/0x90 [ 2.126666] [] warn_slowpath_fmt+0x4c/0x50 [ 2.126666] [] check_flags.part.41+0xc0/0x200 [ 2.126666] [] lock_acquire+0x119/0x240 [ 2.126666] [] ? ring_buffer_unlock_commit+0x33/0x290 [ 2.126666] [] ? ftrace_raw_output_itimer_expire+0x80/0x80 [ 2.126666] [] call_timer_fn+0x83/0x530 [ 2.126666] [] ? call_timer_fn+0x5/0x530 [ 2.126666] [] run_timer_softirq+0x314/0x520 [ 2.126666] [] ? trace_hardirqs_on+0xd/0x10 [ 2.126666] [] ? ftrace_raw_output_itimer_expire+0x80/0x80 [ 2.126666] [] __do_softirq+0x1f8/0x6f0 [ 2.126666] [] irq_exit+0xd5/0xe0 [ 2.126666] [] smp_apic_timer_interrupt+0x86/0xc0 [ 2.126666] [] apic_timer_interrupt+0x6f/0x80 [ 2.126666] [] ? ftrace_likely_update+0x11e/0x250 [ 2.126666] [] ? native_safe_halt+0x6/0x10 [ 2.126666] [] default_idle+0x124/0x440 [ 2.126666] [] arch_cpu_idle+0x36/0x40 [ 2.126666] [] cpu_startup_entry+0x436/0x7e0 [ 2.126666] [] ? clockevents_register_device+0x11c/0x1d0 [ 2.126666] [] start_secondary+0x2b8/0x2c0 [ 2.126666] ---[ end trace 7bbf806df5469d34 ]--- [ 2.126666] possible reason: unannotated irqs-on. [ 2.126666] irq event stamp: 16541 [ 2.126666] hardirqs last enabled at (16540): [] _raw_spin_unlock_irq+0x2e/0x80 [ 2.126666] hardirqs last disabled at (16541): [] ftrace_likely_update+0x87/0x250 [ 2.126666] softirqs last enabled at (16532): [] irq_enter+0x90/0xa0 [ 2.126666] softirqs last disabled at (16533): [] irq_exit+0xd5/0xe0 [ 2.183568] BUG: unable to handle kernel NULL pointer dereference at (null) [ 2.186666] IP: [] find_next_bit+0x141/0x190 [ 2.186666] PGD 0 [ 2.186666] Oops: 0000 [#1] SMP [ 2.186666] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 3.10.0-rc1-00058-g57b8c53 #16 [ 2.186666] task: ffff88000d0d8000 ti: ffff88000d140000 task.ti: ffff88000d140000 [ 2.186666] RIP: 0010:[] [] find_next_bit+0x141/0x190 [ 2.186666] RSP: 0000:ffff88000d141de0 EFLAGS: 00010046 [ 2.186666] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 2.186666] RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000002 [ 2.186666] RBP: ffff88000d141de0 R08: 0000000000000000 R09: 0000000000000000 [ 2.186666] R10: 0000000000000000 R11: 00012f2478ebe8ab R12: ffffffff82478830 [ 2.186666] R13: 00000000ffffffff R14: ffffffff82a08020 R15: 0000000000000000 [ 2.186666] FS: 0000000000000000(0000) GS:ffff88000dc00000(0000) knlGS:0000000000000000 [ 2.186666] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 2.186666] CR2: 0000000000000000 CR3: 0000000002409000 CR4: 00000000000006e0 [ 2.186666] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2.186666] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 2.186666] Stack: [ 2.186666] ffff88000d141e10 ffffffff8118900c ffff88000d15b200 ffffffff83705860 [ 2.186666] 0000000000000000 ffffffff83705860 ffff88000d141e60 ffffffff8118e48f [ 2.186666] ffff88000d141e70 ffff88000d141e48 0000000000000282 ffffffff83705860 [ 2.186666] Call Trace: [ 2.186666] [] ring_buffer_entries+0x6c/0xb0 [ 2.186666] [] trace_test_buffer+0x7f/0x250 [ 2.186666] [] trace_selftest_startup_branch+0x47/0xc0 [ 2.186666] [] register_tracer+0x1f7/0x300 [ 2.186666] [] ? init_mmio_trace+0x12/0x12 [ 2.186666] [] init_branch_tracer+0x33/0x35 [ 2.186666] [] do_one_initcall+0x87/0x191 [ 2.186666] [] kernel_init_freeable+0x10d/0x1c5 [ 2.186666] [] ? do_early_param+0xc1/0xc1 [ 2.186666] [] ? rest_init+0x180/0x180 [ 2.186666] [] kernel_init+0xe/0x210 [ 2.186666] [] ret_from_fork+0x7c/0xb0 [ 2.186666] [] ? rest_init+0x180/0x180 [ 2.186666] Code: ff ff ff 0f 1f 80 00 00 00 00 48 85 f6 0f 94 c1 0f b6 c1 48 83 c0 02 48 83 04 c5 68 66 73 82 01 84 c9 4c 89 c 0 0f 85 78 ff ff ff <48> 8b 02 b9 40 00 00 00 48 c7 c2 ff ff ff ff 29 f1 48 d3 ea 48 [ 2.186666] RIP [] find_next_bit+0x141/0x190 [ 2.186666] RSP [ 2.186666] CR2: 0000000000000000 [ 2.186666] ---[ end trace 7bbf806df5469d35 ]--- [ 2.186666] Kernel panic - not syncing: Fatal exception git bisect bad 57b8c53a06365253d83d4fae03353107dd059884 # 22:00 0- KVM: MMU: document fast invalidate all mmio sptes git bisect bad 8915aa27d5efbb9185357175b0acf884325565f9 # 22:01 0- KVM: x86: handle idiv overflow at kvm_write_tsc git bisect bad c1be5a5b1b355d40e6cf79cc979eb66dafa24ad1 # 22:07 0- Linux 3.9 git bisect bad 19f949f52599ba7c3f67a5897ac6be14bfcb1200 # 22:11 0- Linux 3.8 git bisect bad 29594404d7fe73cd80eaa4ee8c43dcc53970c60e # 22:16 0- Linux 3.7 git bisect bad a0d271cbfed1dd50278c6b06bead3d00ba0a88f9 # 22:21 0- Linux 3.6 git bisect bad 28a33cbc24e4256c143dce96c7d93bf423229f92 # 22:25 0- Linux 3.5 git bisect bad 76e10d158efb6d4516018846f60c2ab5501900bc # 22:29 0- Linux 3.4 git bisect bad c16fa4f2ad19908a47c63d8fa436a1178438c7e7 # 22:33 0- Linux 3.3 git bisect bad 805a6af8dba5dfdd35ec35dc52ec0122400b2610 # 22:37 0- Linux 3.2 git bisect bad c3b92c8787367a8bb53d57d9789b558f1295cc96 # 22:40 0- Linux 3.1 git bisect bad 02f8c6aee8df3cdc935e9bdd4f2d020306035dbe # 22:44 0- Linux 3.0 git bisect bad 61c4f2c81c61f73549928dfd9f3e8f26aa36a8cf # 22:48 0- Linux 2.6.39 git bisect bad f71194a7d47c1da787555d27aac63973ca72323b # 23:30 0- Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect bad e1a86578747376f08985627c84df088a5d0d1e92 # 23:34 0- Add linux-next specific files for 20130621 Thanks, Fengguang