TWIMC: this mail is primarily send for documentation purposes and for
regzbot, my Linux kernel regression tracking bot. These mails usually
contain '#forregzbot' in the subject, to make them easy to spot and filter.
On 06.09.22 12:48, David Laight wrote:
> From: Alexey Dobriyan
>> Sent: 05 September 2022 18:33
>>>> -----Original Message-----
>>>> From: David Laight <David.Laight@xxxxxxxxxx>
>>>> Sent: 04 September 2022 15:05
>>>>
>>>> Sometime after 5.10.105 (5.10.132 and 6.0) there is a change that
>>>> makes setns(open("/proc/1/ns/net")) in the main process changes
>>>> the behaviour of other process threads.
>>
>> Not again...
>
> I've realised what is going on.
> It really isn't obvious at all.
> Quite possibly the last change did fix it - even though
> it broke our code.
In that case this seems to be appropriate, unless I misunderstood things:
#regzbot invalid: apparently not a regression
> /proc/net is a symlink to /proc/self/net.
> But that isn't what the code wants to open.
> What it needs is /proc/self/task/self/net.
> But there isn't a 'self' in /proc/self/task.
> Which makes it all a bit tedious (especially without gettid() in glibc).
> (This is a busybox/buildroot system, maybe I could add it!)
>
> I'd probably have noticed earlier if the /proc/net
> symlink didn't exist.
> I guess that is for compatibility with pre-netns kernels.
>
> David
