From: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
To: "Ma, Xindong" <xindong.ma@intel.com>
Cc: "stable@vger.kernel.org" <stable@vger.kernel.org>,
"Wysocki, Rafael J" <rafael.j.wysocki@intel.com>,
"ccross@google.com" <ccross@google.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"dvhart@linux.intel.com" <dvhart@linux.intel.com>,
"mingo@kernel.org" <mingo@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Tu, Xiaobing" <xiaobing.tu@intel.com>
Subject: Re: Add memory barrier when waiting on futex
Date: Mon, 25 Nov 2013 06:32:31 -0800 [thread overview]
Message-ID: <20131125143231.GB4003@kroah.com> (raw)
In-Reply-To: <3917C05D9F83184EAA45CE249FF1B1DD0252FAEA@SHSMSX103.ccr.corp.intel.com>
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.ma@intel.com>
> Signed-off-by: xiaobing tu <xiaobing.tu@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>
next prev parent reply other threads:[~2013-11-25 14:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-25 13:15 Add memory barrier when waiting on futex Ma, Xindong
2013-11-25 14:32 ` gregkh [this message]
2013-11-25 14:39 ` Peter Zijlstra
2013-11-25 19:18 ` Darren Hart
2013-11-26 1:07 ` Ma, Xindong
2013-11-26 8:26 ` Peter Zijlstra
2013-11-27 0:28 ` Ma, Xindong
2013-11-26 8:50 ` Peter Zijlstra
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