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Message-ID: <b39cdb9c-aa2a-0f49-318b-8632b2989433@linaro.org>
Date:   Thu, 9 Jun 2022 07:30:41 -0700
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Subject: Re: [cgroup] 3c87862ca1:
 WARNING:at_kernel/softirq.c:#__local_bh_enable_ip
Content-Language: en-US
To:     kernel test robot <oliver.sang@intel.com>
Cc:     0day robot <lkp@intel.com>, Tejun Heo <tj@kernel.org>,
        Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Christian Brauner <brauner@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, cgroups@vger.kernel.org,
        lkp@lists.01.org, Michal Koutny <mkoutny@suse.com>,
        netdev@vger.kernel.org, bpf@vger.kernel.org,
        stable@vger.kernel.org,
        syzbot+e42ae441c3b10acf9e9d@syzkaller.appspotmail.com,
        =?UTF-8?Q?Michal_Koutn=c3=bd?= <mkoutny@suse.com>
References: <20220609085641.GB17678@xsang-OptiPlex-9020>
From:   Tadeusz Struk <tadeusz.struk@linaro.org>
In-Reply-To: <20220609085641.GB17678@xsang-OptiPlex-9020>
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On 6/9/22 01:56, kernel test robot wrote:
> 
> Greeting,
> 
> FYI, we noticed the following commit (built with gcc-11):
> 
> commit: 3c87862ca13147416d900cf82ca56bb2f23910bf ("[PATCH v2] cgroup: serialize css kill and release paths")
> url:https://github.com/intel-lab-lkp/linux/commits/Tadeusz-Struk/cgroup-serialize-css-kill-and-release-paths/20220606-014132
> base:https://git.kernel.org/cgit/linux/kernel/git/tj/cgroup.git  for-next
> patch link:https://lore.kernel.org/netdev/20220603181321.443716-1-tadeusz.struk@linaro.org
> 
> in testcase: boot
> 
> on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> 
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
> 
> 
> 
> If you fix the issue, kindly add following tag
> Reported-by: kernel test robot<oliver.sang@intel.com>
> 
> 
> [ 55.821003][ C1] WARNING: CPU: 1 PID: 1 at kernel/softirq.c:363 __local_bh_enable_ip (kernel/softirq.c:363)

Looks like that will need to be spin_lock_irq(&css->lock) instead of spin_lock_bh(&css->lock)
I can respin the patch, but I would like to request some feedback on it first.

Tejun, Michal
Are you interested in fixing this at syzbot issue all? Do you have any more feedback on this?

-- 
Thanks,
Tadeusz