Re: CVS commit: src/sys/arch/x86/x86

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

Hi maxv@n.o,

On 2017/08/08 2:12, Maxime Villard wrote:
> Le 07/08/2017 à 10:38, Kengo NAKAHARA a écrit :
>> "intrctl affinity" in NetBSD-current causes panic. Here is the backtrace
>> ====================
>> panic: kernel diagnostic assertion "mutex_owned(&cpu_lock) || !mp_online" failed: file "/disk4/home/k-nakahara/repos/netbsd-src/sys/arch/x86/x86/idt.c", line 122
>> fatal breakpoint trap in supervisor mode
>> trap type 1 code 0 rip 0xffffffff802249e5 cs 0x8 rflags 0x246 cr2 0x72ca08412d98 ilevel 0 rsp 0xffffe4010e898dc0
>> curlwp 0xffffe4010e88a0c0 pid 0.22 lowest kstack 0xffffe4010e8952c0
>> Stopped in pid 0.22 (system) at netbsd:breakpoint+0x5:  leave
>> db{1}> bt
>> breakpoint() at netbsd:breakpoint+0x5
>> vpanic() at netbsd:vpanic+0x140
>> ch_voltag_convert_in() at netbsd:ch_voltag_convert_in
>> idt_vec_set() at netbsd:idt_vec_set+0x82
>> intr_activate_xcall() at netbsd:intr_activate_xcall+0x8a
>> xc_thread() at netbsd:xc_thread+0xd4
>> ====================
>>
>> ozaki-r@n.o bisects and finds the following commit causes this panic.
>>
>> On 2017/08/01 3:54, Maxime Villard wrote:
>>> Module Name:	src
>>> Committed By:	maxv
>>> Date:		Mon Jul 31 18:54:40 UTC 2017
>>>
>>> Modified Files:
>>> 	src/sys/arch/x86/x86: intr.c
>>>
>>> Log Message:
>>> Use idt_vec_set instead.
>>>
>>>
>>> To generate a diff of this commit:
>>> cvs rdiff -u -r1.101 -r1.102 src/sys/arch/x86/x86/intr.c
>>>
>>> Please note that diffs are not public domain; they are subject to the
>>> copyright notices on the relevant files.
>>
>> I think setgate() must be called with kpreempt_disable() and
>> x86_disable_intr(). However, I don't know why setgate() must be called
>> with mutex_onwed(&cpu_lock). Could you tell me why mutex_onwed(&cpu_lock)
>> is required?
> 
> setgate already disables preemption on amd64, but not on i386. I guess
> this needs to be investigated.

I see. Hmm, I also research about it when I can.


> Otherwise it's fixed, thanks

I test latest kernel(including idt.c:r1.5), and I confirm the bug is
fixed. Thank you.


Thanks,

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Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>