clone09.c: EROFS error when open FILE '/proc/sys/net/ipv4/conf/lo/tag' in container env

[coolgw]

Reproduce Step:

1. Using container file create docker img: https://github.com/richiejp/ltp/blob/alpine-container/Containerfile
2. docker run -it --rm xxx /bin/sh
3. run following command
   /opt/ltp # ./testcases/bin/clone09
   tst_test.c:1684: TINFO: LTP version: 20220930-713-g126db850c
   tst_test.c:1568: TINFO: Timeout per run is 0h 00m 30s
   clone09.c:59: TINFO: create clone in a new netns with 'CLONE_NEWNET' flag
   clone09.c:62: TBROK: Failed to open FILE '/proc/sys/net/ipv4/conf/lo/tag' for writing: EROFS (30)

Other info in container:
/opt/ltp # ls -l /proc/sys/net/ipv4/conf/lo/tag
-rw-r--r-- 1 root root 0 Sep 26 07:02 /proc/sys/net/ipv4/conf/lo/tag
/opt/ltp # whoami
root
/opt/ltp # mount
proc on /proc/sys type proc (ro,nosuid,nodev,noexec,relatime)

[Martchus]

Maybe a change similar to what I did for #1082 should be applied here as well?

[coolgw]

Maybe a change similar to what I did for #1082 should be applied here as well?
I suggest wait @pevik @richiejp 's feedback, change code or tune the setup of container etc..

[coolgw]

Just FYI @Martchus
Following patch change the container's setup and use normal user instead of root, then if you run case with normal user the error will not happen.
https://patchwork.ozlabs.org/project/ltp/patch/20230926090101.7565-1-rpalethorpe@suse.com/

[coolgw]

Just FYI @Martchus Following patch change the container's setup and use normal user instead of root, then if you run case with normal user the error will not happen. https://patchwork.ozlabs.org/project/ltp/patch/20230926090101.7565-1-rpalethorpe@suse.com/

https://patchwork.ozlabs.org/project/ltp/patch/20231009102405.26471-1-rpalethorpe@suse.com/ merge in LTP.