[oe] [OE-core] [PATCH] telnetd:Fix deadlock on cleanup

[Seiichi Ishitsuka]

> Please check will latest master, if you can reporduce the issue with master then we can revive this discussion on the patch.

I was able to reproduce this issue on qemux86 with the latest version.

Build Configuration:
BB_VERSION           = "1.37.0"
BUILD_SYS            = "x86_64-linux"
NATIVELSBSTRING      = "universal"
TARGET_SYS           = "i586-poky-linux"
MACHINE              = "qemux86"
DISTRO               = "poky"
DISTRO_VERSION       = "2.5"
TUNE_FEATURES        = "m32 i586"
TARGET_FPU           = ""
meta
meta-poky
meta-yocto-bsp       = "master:719d068bde55ef29a3468bc0779d4cb0c11e8c1d"
meta-oe
meta-python
meta-networking      = "master:bb57bac845f3cd1634862fa9868bc8e294ba74a9"

How to reproduce:

1. telnet from host(192.168.7.1) to qemux86(192.168.7.2)

$ cat ./telnetd.sh
 #!/bin/sh

 HOST="192.168.7.2"
 USER="root"

 while :
 do
   expect -c "
   set timeout 10
   spawn telnet $HOST
   expect login:\  ; send \"$USER\r\"
   expect \"# \" ; send \"exit\r\"
 "> /dev/null
 done

$ ./telnetd.sh &
$ ./telnetd.sh &

2. Check process status on qemux86

root       325     1  0 04:41 ?        00:00:01 /usr/sbin/xinetd -pidfile /var/r
root      3328   325  0 04:43 ?        00:00:00 in.telnetd: 192.168.7.1
root      3330  3328  0 04:43 ?        00:00:00 [sh] <defunct>
root      3374   325  0 04:43 ?        00:00:00 in.telnetd: 192.168.7.1
root      3376  3374  0 04:43 ?        00:00:00 [sh] <defunct>
root      3417   306  0 04:44 ttyS0    00:00:00 ps -ef

-> Found defunct sh and in.telnetd(waiting futex). 

root at qemux86:~# strace -p 3328
strace: Process 3328 attached
futex(0x45055a18, FUTEX_WAIT_PRIVATE, 2, NULL^Cstrace: Process 3328 detached
 <detached ...>

root at qemux86:~# strace -p 3374
strace: Process 3374 attached
futex(0x45055a18, FUTEX_WAIT_PRIVATE, 2, NULL^Cstrace: Process 3374 detached
 <detached ...>

Best regards,
Seiichi Ishitsuka