From: "Shi, Yang" <yang.shi@linaro.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: tglx@linutronix.de, rostedt@goodmis.org,
linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org,
linaro-kernel@lists.linaro.org
Subject: Re: [PATCH] rt: x86: extend signal send delay to 32 bit
Date: Fri, 11 Dec 2015 11:43:22 -0800 [thread overview]
Message-ID: <566B275A.5070300@linaro.org> (raw)
In-Reply-To: <20151211180532.GO6720@linutronix.de>
On 12/11/2015 10:05 AM, Sebastian Andrzej Siewior wrote:
> * Yang Shi | 2015-12-10 10:58:51 [-0800]:
>
>> When running some ptrace single step tests on x86-32 machine, the below problem
>> is triggered:
>>
>> BUG: sleeping function called from invalid context at linux-rt/kernel/locking/rtmutex.c:917
>> in_atomic(): 1, irqs_disabled(): 0, pid: 1041, name: dummy2
>> INFO: lockdep is turned off.
>> Preemption disabled at:[<c100326f>] do_debug+0x1f/0x1a0
>>
>> CPU: 10 PID: 1041 Comm: dummy2 Tainted: G W 4.1.13-rt13 #1
>> Hardware name: Intel Corporation S5520HC/S5520HC, BIOS S5500.86B.01.10.0025.030220091519 03/02/2009
>> 00000000 00000000 e1811e80 c1aa8306 00000000 e1811ea8 c1080517 c1d8b2e8
>> c100326f c100326f 00000411 e5b7d5b4 e1d521c4 00000005 e1811f74 e1811ec4
>> c1ab0eff e1d51cc0 e5b7d180 c1081403 e5b7d180 e5b7d180 e1811ee4 c1064b5a
>> Call Trace:
>> [<c1aa8306>] dump_stack+0x46/0x5c
>> [<c1080517>] ___might_sleep+0x137/0x220
>> [<c100326f>] ? do_debug+0x1f/0x1a0
>> [<c100326f>] ? do_debug+0x1f/0x1a0
>> [<c1ab0eff>] rt_spin_lock+0x1f/0x80
>> [<c1081403>] ? preempt_count_sub+0xb3/0x110
>> [<c1064b5a>] do_force_sig_info+0x2a/0xc0
>> [<c106567d>] force_sig_info+0xd/0x10
>> [<c1010cff>] send_sigtrap+0x6f/0x80
>> [<c10033b1>] do_debug+0x161/0x1a0
>> [<c1ab2921>] debug_stack_correct+0x2e/0x35
>>
>> Signal send delay is just available for x86-64, x86-32 needs it too.
>
> This is new, this was not the case earlier. New means since v4.0-rc1 which
Yes, it is. We didn't find this problem in earlier version kernel (I'd
say 3.x).
> is when 959274753857 ("x86, traps: Track entry into and exit from IST
> context") got merged.
> Since now ist_enter() disables preemption in any case, our hacks to
> conditional_sti_ist() are pointless and could be removed.
I'm supposed you will revert it and not need a revert patch from me.
Thanks for the deeper cause analysis.
Yang
>
> Sebastian
>
next prev parent reply other threads:[~2015-12-11 19:43 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-10 18:58 [PATCH] rt: x86: extend signal send delay to 32 bit Yang Shi
2015-12-11 18:05 ` Sebastian Andrzej Siewior
2015-12-11 19:43 ` Shi, Yang [this message]
2015-12-12 14:35 ` Thomas Gleixner
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