Re: [PATCH 4.19 21/57] proc: dont allow async path resolution of /proc/self components

From: Jens Axboe
Date: Tue Mar 02 2021 - 15:31:40 EST


On 3/2/21 1:40 AM, Yang Yingliang wrote:
> Hi,
>
> On 2020/12/1 16:53, Greg Kroah-Hartman wrote:
>> From: Jens Axboe <axboe@xxxxxxxxx>
>>
>> [ Upstream commit 8d4c3e76e3be11a64df95ddee52e99092d42fc19 ]
>>
>> If this is attempted by a kthread, then return -EOPNOTSUPP as we don't
>> currently support that. Once we can get task_pid_ptr() doing the right
>> thing, then this can go away again.
>
> https://www.spinics.net/lists/io-uring/msg05297.html
>
> This patch seems used for io-wq worker which is merged in
>
> v5.5-rc1, why we need this in linux-4.19.y ?

While that's true, it's also a sane safeguard in general.

--
Jens Axboe