resolv/tst-resolv-res_init fails with unshare (CLONE_NEWUTS) failed: Operation not permitted

resolv/tst-resolv-res_init fails with unshare (CLONE_NEWUTS) failed: Operation not permitted

[John Lumby]

Apologies if this has been answered elsewhere.

under linux-5.16.9 I am building and testing glibc-2.35 and get one FAIL in the test suite :   glibc-build/resolv/tst-resolv-res_init.out contains :

warning: could not become root outside namespace (Operation not permitted)
warning: unshare (CLONE_NEWUTS) failed: Operation not permitted
warning: could not enter network namespace

I think the cause if that is this code in support/support_become_root.c

       unshare (CLONE_NEWUSER | CLONE_NEWNS)

is getting EPERM.

After reading the man page for unshare() I am none the wiser about whether  :
    .   the userid running the test is missing some capability that is needed in order to run the test  -  if so ,   what?
    .   there is some environmental problem   -  if so ,   how can I find out what?
    .  or is this test supposed to be run by root? (I think not but unclear)

I am sure the answer is buried somewhere in some doc but if anyone can help me get there I would be grateful.

Cheers,   John Lumby

Re: resolv/tst-resolv-res_init fails with unshare (CLONE_NEWUTS) failed: Operation not permitted

[Florian Weimer]

* John Lumby via Libc-help:

> Apologies if this has been answered elsewhere.
>
> under linux-5.16.9 I am building and testing glibc-2.35 and get one FAIL in the test suite :   glibc-build/resolv/tst-resolv-res_init.out contains :
>
> warning: could not become root outside namespace (Operation not permitted)
> warning: unshare (CLONE_NEWUTS) failed: Operation not permitted
> warning: could not enter network namespace
>
> I think the cause if that is this code in support/support_become_root.c
>
>        unshare (CLONE_NEWUSER | CLONE_NEWNS)
>
> is getting EPERM.

It's just a warning, so it shouldn't cause a test failure.

Are there any other messages in the resolv/tst-resolv-res_init.out file?

Thanks,
Florian

Re: resolv/tst-resolv-res_init fails with unshare (CLONE_NEWUTS) failed: Operation not permitted

[John Lumby]

Thanks Florian  -

My ooppss  -    the FAIL was actually on
FAIL: resolv/tst-resolv-res_init-multi

But I looked in tst-resolv-res_init.out -    I should have looked in tst-resolv-res_init-multi.out   -    where I see something completely different  - a timeout  (which I think I have seen before)

Sorry for false alarm   (although now I have learned about unshare :-)

Cheers,   John Lumby

From: Florian Weimer <fweimer@redhat.com>
Sent: March 1, 2022 2:25 PM
To: John Lumby via Libc-help <libc-help@sourceware.org>
Cc: John Lumby <johnlumby@hotmail.com>
Subject: Re: resolv/tst-resolv-res_init fails with unshare (CLONE_NEWUTS) failed: Operation not permitted 
 
* John Lumby via Libc-help:

> Apologies if this has been answered elsewhere.
>
> under linux-5.16.9 I am building and testing glibc-2.35 and get one FAIL in the test suite :   glibc-build/resolv/tst-resolv-res_init.out contains :
>
> warning: could not become root outside namespace (Operation not permitted)
> warning: unshare (CLONE_NEWUTS) failed: Operation not permitted
> warning: could not enter network namespace
>
> I think the cause if that is this code in support/support_become_root.c
>
>        unshare (CLONE_NEWUSER | CLONE_NEWNS)
>
> is getting EPERM.

It's just a warning, so it shouldn't cause a test failure.

Are there any other messages in the resolv/tst-resolv-res_init.out file?

Thanks,
Florian