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Subject: Re: general protection fault vs Oops
To:     =?UTF-8?Q?Valdis_Kl=c4=93tnieks?= <valdis.kletnieks@vt.edu>,
        Subhashini Rao Beerisetty <subhashbeerisetty@gmail.com>
Cc:     kernelnewbies <kernelnewbies@kernelnewbies.org>,
        linux-kernel@vger.kernel.org
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 <374485.1589637193@turing-police>
From:   Randy Dunlap <rdunlap@infradead.org>
Message-ID: <af03bee5-27b2-4e92-359a-b1cc8f500d6d@infradead.org>
Date:   Sat, 16 May 2020 08:59:53 -0700
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On 5/16/20 6:53 AM, Valdis Klētnieks wrote:
> On Sat, 16 May 2020 18:05:07 +0530, Subhashini Rao Beerisetty said:
> 
>> In the first attempt when I run that test case I landed into â€œgeneral
>> protection fault: 0000 [#1] SMP" .. Next I rebooted and ran the same
>> test , but now it resulted the â€œOops: 0002 [#1] SMP".
> 
> And the 0002 is telling you that there's been 2 previous bug/oops since the
> reboot, so you need to go back through your dmesg and find the *first* one.
> 
>> In both cases the call trace looks exactly same and RIP points to
>> â€œnative_queued_spin_lock_slowpath+0xfe/0x170"..
> 
> The first few entries in the call trace are the oops handler itself. So...
> 
> 
>> May 16 12:06:17 test-pc kernel: [96934.567347] Call Trace:
>> May 16 12:06:17 test-pc kernel: [96934.569475]  [<ffffffff8183c427>]__raw_spin_lock_irqsave+0x37/0x40
>> May 16 12:06:17 test-pc kernel: [96934.571686]  [<ffffffffc0606812>] event_raise+0x22/0x60 [osa]
>> May 16 12:06:17 test-pc kernel: [96934.573935]  [<ffffffffc06aa2a4>] multi_q_completed_one_buffer+0x34/0x40 [mcore]
> 
> The above line is the one where you hit the wall.
> 
>> May 16 12:59:22 test-pc kernel: [ 3011.405602] Call Trace:
>> May 16 12:59:22 test-pc kernel: [ 3011.407892]  [<ffffffff8183c427>] _raw_spin_lock_irqsave+0x37/0x40
>> May 16 12:59:22 test-pc kernel: [ 3011.410256]  [<ffffffffc0604812>] event_raise+0x22/0x60 [osa]
>> May 16 12:59:22 test-pc kernel: [ 3011.412652]  [<ffffffffc06b72a4>] multi_q_completed_one_buffer+0x34/0x40 [mcore]
> 
> And again.
> 
> However,  given that it's a 4.4 kernel from 4 years ago, it's going to be
> hard to find anybody who really cares.

Right.

> In fact. I'm wondering if this is from some out-of-tree or vendor patch,
> because I'm not finding any sign of that function in either the 5.7 or 4.4
> tree.  Not even a sign of ## catenation abuse - no relevant hits for
> "completed_one_buffer" or "multi_q" either

Modules linked in:
dbg(OE) mcore(OE) osa(OE)

Out-of-tree, unsigned modules loaded.
We don't know what those are or how to debug them.

> I don't think anybody's going to be able to help unless somebody first
> identifies where that function is....
> 


-- 
~Randy