[CRIU] [PATCH v3 00/55] Nested pid namespaces support

[Kirill Tkhai]

On 13.04.2017 02:39, Andrei Vagin wrote:
> On Tue, Apr 11, 2017 at 03:10:27PM +0300, Kirill Tkhai wrote:
>> On 11.04.2017 07:26, Andrei Vagin wrote:
>>> [root at fc24 criu]# python test/zdtm.py run -t zdtm/static/pidns00 --iter 1
>>> Checking feature ns_pid
>>> === Run 1/1 ================ zdtm/static/pidns00
>>>
>>> ======================== Run zdtm/static/pidns00 in ns =========================
>>> make[1]: Nothing to be done for 'default'.
>>> Start test
>>> Test is SUID
>>> make[1]: Nothing to be done for 'default'.
>>> ./pidns00 --pidfile=pidns00.pid --outfile=pidns00.out
>>> Run criu dump
>>> Run criu restore
>>> ################ Test zdtm/static/pidns00 FAIL at CRIU restore #################
>>> ##################################### FAIL #####################################
>>> [root at fc24 criu]# dmesg -c
>>> [439441.751893] traps: pidns00[27458] general protection ip:7f9b3183d642 sp:7ffc2d9587c0 error:0
>>> [439441.751900]  in libc.so.6[7f9b31806000+1bd000]
>>> [439441.768416] systemd-journald[13102]: Successfully sent stream file descriptor to service manager.
>>> [439441.886503] systemd-journald[13102]: Compressed data object 1176 -> 652 using LZ4
>>> [439441.887834] systemd-journald[13102]: Compressed data object 1658 -> 653 using LZ4
>>> [439441.889093] systemd-journald[13102]: Compressed data object 3128 -> 1774 using LZ4
>>> [439442.037519] criu[27482]: segfault at 12 ip 000000000047e4d3 sp 00007ffc190820a8 error 4 in criu[400000+117000]
>>> [439442.058973] systemd-journald[13102]: Successfully sent stream file descriptor to service manager.
>>> [439442.211795] systemd-journald[13102]: Compressed data object 1150 -> 665 using LZ4
>>> [439442.213101] systemd-journald[13102]: Compressed data object 5493 -> 1619 using LZ4
>>> [root at fc24 criu]# 
>>> [root at fc24 criu]# git diff
>>> diff --git a/test/zdtm/static/pidns00.c b/test/zdtm/static/pidns00.c
>>> index e3ed74b..e86d488 100644
>>> --- a/test/zdtm/static/pidns00.c
>>> +++ b/test/zdtm/static/pidns00.c
>>> @@ -54,6 +54,11 @@ futex_t *futex;
>>>  
>>>  int child(void)
>>>  {
>>> +       int fd = open("/proc/self/ns/pid", O_RDONLY);
>>> +       unshare(CLONE_NEWPID);
>>> +       if (fork())
>>> +               setns(fd, CLONE_NEWPID);
>>> +       close(fd);
>>>         futex_wait_while_lt(futex, 1);
>>>         return 0;
>>>  }
>>
>> The below fixes the issue. Thanks for finding this!
>>
>> diff --git a/criu/pstree.c b/criu/pstree.c
>> index b2703dd01..d032957ae 100644
>> --- a/criu/pstree.c
>> +++ b/criu/pstree.c
>> @@ -844,7 +844,7 @@ int get_free_pid(struct ns_id *ns)
>>  		node = rb_next(&prev->ns[level].node);
>>  		if (node == NULL)
>>  			return pid;
>> -		next = rb_entry(node, struct pid, ns[0].node);
>> +		next = rb_entry(node, struct pid, ns[level].node);
> 
> Now criu restore hangs
> 
>  8270 pts/0    T      0:00              \_ python test/zdtm.py run -t zdtm/static/pidns00
>  8281 pts/0    T      0:00              |   \_ ./zdtm_ct zdtm.py
>  8282 pts/0    S      0:00              |       \_ python2 zdtm.py
>  8284 pts/0    T      0:00              |           \_ python2 zdtm.py
>  8343 pts/0    S      0:00              |               \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidns00.pid --ro
>  8348 pts/0    S      0:00              |                   \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidns00.pid 
>  8361 pts/0    S      0:00              |                   |   \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidns00.
>  8367 pts/0    S      0:00              |                   |   \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidns00.
>  8369 pts/0    S      0:00              |                   |   \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidns00.
>  8370 pts/0    S      0:00              |                   |   \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidns00.
>  8349 pts/0    S      0:00              |                   \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidns00.pid 
>  8362 pts/0    S      0:00              |                       \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidns00.
>  8363 pts/0    S      0:00              |                           \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidn
>  8366 pts/0    S      0:00              |                           |   \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/
>  8364 pts/0    S      0:00              |                           \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidn
>  8365 pts/0    S      0:00              |                           \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/pidn
>  8368 pts/0    S      0:00              |                               \_ ../criu/criu restore -o restore.log -D dump/zdtm/static/pidns00/29/1 -v4 --pidfile /root/git/criu/test/zdtm/static/
>  8371 pts/0    R+     0:00              \_ ps axf

Could you start the test with --sbs? I suppose, zombies are there for some reasons, and they are not appropriate dumped.