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Date: Thu, 2 Apr 2026 09:25:55 -0500
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Subject: Re: Panic: "knote ... was already on knlist..." after
 main-n284826-d9d7b5948649
To: David Wolfskill <david@catwhisker.org>,
 Konstantin Belousov <kostikbel@gmail.com>, current@freebsd.org
References: <ac5mIAT2mREod9OK@albert.catwhisker.org>
 <ac5otmIUJkRwNY8q@kib.kiev.ua> <ac5tG2euI0F6INfM@albert.catwhisker.org>
Content-Language: en-US
From: Kyle Evans <kevans@FreeBSD.org>
In-Reply-To: <ac5tG2euI0F6INfM@albert.catwhisker.org>
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On 4/2/26 08:20, David Wolfskill wrote:
> On Thu, Apr 02, 2026 at 04:01:42PM +0300, Konstantin Belousov wrote:
>> ...
>> Peter Holm already reported this or similar issue.  Try this please.
> 
> Ah.
> 
>> commit 5da1dcf8b88ffa3591a84405a8ab29ebd846f2e0
>> Author: Konstantin Belousov <kib@FreeBSD.org>
>> Date:   Thu Apr 2 14:02:14 2026 +0300
>>
>>      kqueue_fork_copy_knote(): zero kn_knlist for the copy before calling knlist_add()
>> ...
> 
> Change made; works -- thanks!
> 

I know it's not much consolation *after* I've blown up your machines, but I wrote a regression
test that covers this scenario:

https://reviews.freebsd.org/D56223

Thanks,

Kyle Evan