On Mon, Nov 25, 2013 at 01:15:17PM +0000, Ma, Xindong wrote: > We encountered following panic several times: > [ 74.671982] BUG: unable to handle kernel NULL pointer dereference at > 00000008 > [ 74.672101] IP: [<c129bb27>] wake_futex+0x47/0x80 > [ 74.672185] *pdpt = 0000000010108001 *pde = 0000000000000000 > [ 74.672278] Oops: 0002 [#1] PREEMPT SMP > [ 74.672403] Modules linked in: atomisp_css2400b0_v2 atomisp_css2400_v2 > dfrgx bcm_bt_lpm videobuf_vmalloc videobuf_core hdmi_audio tngdisp bcm4335 > kct_daemon(O) cfg80211 > [ 74.672815] CPU: 0 PID: 1477 Comm: zygote Tainted: G W O > 3.10.1-259934-g0bfb86e #1 > [ 74.672855] Hardware name: Intel Corporation Merrifield/SALT BAY, BIOS 404 > 2013.10.09:15.29.48 > [ 74.672894] task: d4c97220 ti: cfaa8000 task.ti: cfaa8000 > [ 74.672933] EIP: 0060:[<c129bb27>] EFLAGS: 00210246 CPU: 0 > [ 74.672975] EIP is at wake_futex+0x47/0x80 > [ 74.673012] EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: 00000000 > [ 74.673049] ESI: def4de5c EDI: ffffffff EBP: cfaa9eb4 ESP: cfaa9ea0 > [ 74.673086] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 > [ 74.673123] CR0: 8005003b CR2: 00000008 CR3: 10109000 CR4: 001007f0 > [ 74.673160] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 > [ 74.673196] DR6: ffff0ff0 DR7: 00000400 > [ 74.673229] Stack: > [ 74.673260] 00000000 00000001 00000000 def4de5c c225eb50 cfaa9ee4 > c129bc29 00000000 > [ 74.673536] 00000000 7fffffff c225eb30 b4f38000 ec1a4b40 00000f90 > 7fffffff 00000001 > [ 74.673814] b4f38f90 cfaa9f58 c129da0b ffffffff ffffffff cfaa9f10 > c195d835 00000001 > [ 74.674092] Call Trace: > [ 74.674144] [<c129bc29>] futex_wake+0xc9/0x110 > [ 74.674195] [<c129da0b>] do_futex+0xeb/0x950 > [ 74.674246] [<c195d835>] ? sub_preempt_count+0x55/0xe0 > [ 74.674293] [<c1275aee>] ? wake_up_new_task+0xee/0x190 > [ 74.674341] [<c195a31b>] ? _raw_spin_unlock_irqrestore+0x3b/0x70 > [ 74.674388] [<c1275aee>] ? wake_up_new_task+0xee/0x190 > [ 74.674436] [<c1241afc>] ? do_fork+0xec/0x350 > [ 74.674484] [<c129e30b>] SyS_futex+0x9b/0x140 > [ 74.674533] [<c1312298>] ? SyS_mprotect+0x188/0x1e0 > [ 74.674582] [<c195a718>] syscall_call+0x7/0xb > > On smp systems, setting current task to q->task in queue_me() may > not visible immediately to another cpu, some times this will > cause panic in wake_futex(). Adding memory barrier to avoid this. > > Signed-off-by: Leon Ma <xindong...@intel.com> > Signed-off-by: xiaobing tu <xiaobing...@intel.com> > --- > kernel/futex.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-)
<formletter> This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read Documentation/stable_kernel_rules.txt for how to do this properly. </formletter> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
