2013/4/26 Sedat Dilek <sedat.dilek@xxxxxxxxx>: > On Fri, Apr 26, 2013 at 8:22 PM, Tejun Heo <tj@xxxxxxxxxx> wrote: >> On Fri, Apr 26, 2013 at 07:40:20PM +0200, Sedat Dilek wrote: >>> Oops, NULL-pointer-deref [ __queue_work() ] >>> >>> [ 25.974932] BUG: unable to handle kernel NULL pointer dereference >>> at 0000000000000100 >>> [ 25.974944] IP: [<ffffffff81077502>] __queue_work+0x32/0x3d0 >> >> So, 0x100 deref near the top of the function. >> >> ... >>> [ 25.975037] RIP: 0010:[<ffffffff81077502>] [<ffffffff81077502>] >>> __queue_work+0x32/0x3d0 >>> [ 25.975047] RSP: 0018:ffff88008fed5c48 EFLAGS: 00010046 >>> [ 25.975052] RAX: 0000000000000096 RBX: 0000000000000292 RCX: 0000000000000000 >>> [ 25.975058] RDX: ffff880095281850 RSI: 0000000000000000 RDI: 0000000000000100 >>> [ 25.975063] RBP: ffff88008fed5c88 R08: 0000000000000000 R09: 0000000000000300 >>> [ 25.975069] R10: ffff880094981a00 R11: 0000000000000000 R12: ffff880095281850 >>> [ 25.975074] R13: 0000000000000000 R14: 0000000000000100 R15: 00000000000009c4 >>> [ 25.975081] FS: 00007f2f61707740(0000) GS:ffff88011fac0000(0000) >>> knlGS:0000000000000000 >>> [ 25.975088] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> [ 25.975093] CR2: 0000000000000100 CR3: 000000009101f000 CR4: 00000000000407e0 >>> [ 25.975099] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >>> [ 25.975104] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 >> ... >>> [ 25.975143] Call Trace: >>> [ 25.975151] [<ffffffff81077be5>] queue_work_on+0x45/0x50 >>> [ 25.975165] [<ffffffffa016e8ff>] hci_req_run+0xbf/0xf0 [bluetooth] >>> [ 25.975188] [<ffffffffa016ea06>] __hci_req_sync+0xd6/0x1c0 [bluetooth] >>> [ 25.975217] [<ffffffffa016fad5>] hci_dev_open+0x275/0x2e0 [bluetooth] >>> [ 25.975230] [<ffffffffa0182752>] hci_sock_ioctl+0x1f2/0x3f0 [bluetooth] >>> [ 25.975238] [<ffffffff815c6050>] sock_do_ioctl+0x30/0x70 >>> [ 25.975245] [<ffffffff815c75f9>] sock_ioctl+0x79/0x2f0 >>> [ 25.975254] [<ffffffff811a8046>] do_vfs_ioctl+0x96/0x560 >>> [ 25.975262] [<ffffffff811a85a1>] SyS_ioctl+0x91/0xb0 >>> [ 25.975271] [<ffffffff816d989d>] system_call_fastpath+0x1a/0x1f >>> [ 25.975276] Code: 89 e5 41 57 41 56 41 89 fe 41 55 49 89 f5 41 54 >>> 49 89 d4 53 48 83 ec 18 89 7d c8 9c 58 66 66 90 66 90 f6 c4 02 0f 85 >>> 56 02 00 00 <41> 8b 85 00 01 00 00 a9 00 00 01 00 0f 85 b0 02 00 00 48 >>> c7 c2 >> >> All code >> ======== >> 0: 89 e5 mov %esp,%ebp >> 2: 41 57 push %r15 >> 4: 41 56 push %r14 >> 6: 41 89 fe mov %edi,%r14d >> 9: 41 55 push %r13 >> b: 49 89 f5 mov %rsi,%r13 >> e: 41 54 push %r12 >> 10: 49 89 d4 mov %rdx,%r12 >> 13: 53 push %rbx >> 14: 48 83 ec 18 sub $0x18,%rsp >> 18: 89 7d c8 mov %edi,-0x38(%rbp) >> 1b: 9c pushfq >> 1c: 58 pop %rax >> 1d: 66 66 90 data32 xchg %ax,%ax >> 20: 66 90 xchg %ax,%ax >> 22: f6 c4 02 test $0x2,%ah >> 25: 0f 85 56 02 00 00 jne 0x281 >> 2b:* 41 8b 85 00 01 00 00 mov 0x100(%r13),%eax <-- trapping instruction >> 32: a9 00 00 01 00 test $0x10000,%eax >> 37: 0f 85 b0 02 00 00 jne 0x2ed >> 3d: 48 rex.W >> 3e: c7 .byte 0xc7 >> 3f: c2 .byte 0xc2 >> >> The second argument %rsi is zero, which got transferred to %r13 and >> then offset deref on it trapped. >> >> The second argument is @wq and the oopsing code is the wq->flags deref >> in the following if condition. >> >> /* if dying, only works from the same workqueue are allowed */ >> if (unlikely(wq->flags & __WQ_DRAINING) && >> WARN_ON_ONCE(!is_chained_work(wq))) >> return; >> >> So, umm, don't pass in NULL as @wq. :) >> > > [ CC Frederic (linux-dynticks) ] > > Great, Tejun! > Anyway a bug... > > Just wanted to mention I switched to a full-cpu-dynticks config-setup: > > 1. TICK_CPU_ACCOUNTING -> VIRT_CPU_ACCOUNTING_GEN > > 2. [X] NO_HZ_FULL > > From [2]: > > config VIRT_CPU_ACCOUNTING_GEN > bool "Full dynticks CPU time accounting" > - depends on HAVE_CONTEXT_TRACKING && 64BIT > + depends on HAVE_CONTEXT_TRACKING && 64BIT && NO_HZ_FULL > > Choosing NO_HZ_FULL depends leads to a different kernel-config which > seems not to show the trace. > > - Sedat - > > [1] http://git.kernel.org/cgit/linux/kernel/git/frederic/linux-dynticks.git/log/?h=timers/nohz > [2] http://git.kernel.org/cgit/linux/kernel/git/frederic/linux-dynticks.git/commit/?h=timers/nohz&id=7f40072a53838380e3902d94fae49efed506b34e Hmm that patch shouldn't change the kernel code itself. Do the warning shows unless you run full dynticks?
