luci is blocked when invoking shell commands（c source can also find similar error）

[truelv]

platform： openwrt CC / mips ( 4 cpu core)

Repetition frequency： sometimes happen

wrong lines： luci/modules/admin-full/luasrc/view/admin_status/index.html line97 mac = luci.sys.exec("ifconfig eth0 | awk '/HWaddr/{print $5}'")

PS info： 15 treebear 0 SW [ksoftirqd/2] 16 treebear 0 SW [kworker/2:0] 17 treebear 0 SW< [kworker/2:0H] 18 treebear 0 SW [migration/3] 19 treebear 0 SW [ksoftirqd/3] 20 treebear 0 SW [kworker/3:0] 21 treebear 0 SW< [kworker/3:0H] 22 treebear 0 SW< [khelper] 100 treebear 0 SW< [writeback] 102 treebear 0 SW< [bioset] 104 treebear 0 SW< [kblockd] 117 treebear 0 SW [khubd] 144 treebear 0 RW [kworker/0:1] 150 treebear 0 SW [kswapd0] 194 treebear 0 SW [fsnotify_mark] 266 treebear 0 SW [kworker/3:1] 267 treebear 0 SW [kworker/2:1] 268 treebear 0 SW [kworker/1:1] 280 treebear 0 SW< [deferwq] 382 treebear 0 SWN [jffs2_gcd_mtd6] 461 treebear 888 S /sbin/ubusd 470 treebear 768 S /sbin/askfirst ttyS0 /bin/ash --login 912 treebear 0 SW< [rpciod] 933 treebear 0 SW< [nfsiod] 1164 treebear 1504 S /sbin/klogd 1165 treebear 1528 S /sbin/syslogd -l 7 -O /etc/log/system.log -s 1000 -b 10 -U /tmp/user.log 1166 treebear 0 SW [kworker/0:2] 1202 treebear 1544 S /sbin/netifd 1353 treebear 1508 S udhcpc -R -p /var/run/udhcpc-eth0.5.pid -s /lib/netifd/dhcp.script -f -t 0 -i eth0.5 -H Witown -V #AP:Tre 1466 treebear 1208 S /usr/sbin/dnsmasq -C /var/etc/dnsmasq.conf -k -u treebear 1468 treebear 0 SW< [kworker/1:1H] 1486 treebear 0 SW [RtmpCmdQTask] 1487 treebear 0 SW [RtmpWscTask] 1488 treebear 0 SW [RtmpMlmeTask] 1650 treebear 0 SW [RtmpCmdQTask] 1651 treebear 0 SW [RtmpWscTask] 1652 treebear 0 SW [RtmpMlmeTask] 1745 treebear 1508 S /usr/sbin/telnetd 1769 treebear 1084 S /sbin/mountd -f 1791 treebear 1508 S /usr/sbin/ntpd -n -u 86400 -r 600 -p 0.cn.pool.ntp.org -p 1.cn.pool.ntp.org -p 2.cn.pool.ntp.org -p 3.cn. 1815 treebear 4032 S /usr/sbin/lighttpd -f /etc/lighttpd/lighttpd.conf 1819 treebear 1504 S {runing_status_m} /bin/sh /usr/sbin/runing_status_monitor 1833 treebear 1520 S {update_cur_stat} /bin/sh /usr/sbin/update_cur_status 1870 treebear 1508 S {witownapp.sh} /bin/sh /usr/sbin/witownapp.sh 1905 treebear 980 S arp_broadcast lan 1911 treebear 1508 S /usr/sbin/crond start 1930 treebear 37408 S /usr/bin/ppcloud 2005 treebear 0 SW [kworker/u8:2] 6786 treebear 1520 S -ash 15051 treebear 3320 S {luci} /usr/bin/lua /www/cgi-bin/luci //these three lines below are bocked one bye one 15120 treebear 1512 S sh -c ifconfig eth0 | awk '/HWaddr/{print $5}' 15122 treebear 1512 R sh -c ifconfig eth0 | awk '/HWaddr/{print $5}' 22209 treebear 1500 S sleep 10 22214 treebear 1508 R ps w

Top info： Mem: 83636K used, 172364K free, 0K shrd, 5748K buff, 22196K cached CPU: 4% usr 29% sys 0% nic 50% idle 0% io 0% irq 15% sirq Load average: 1.23 1.33 1.45 2/77 24291 PID PPID USER STAT VSZ %VSZ %CPU COMMAND 15122 15120 treebear R 1512 1% 25% sh -c ifconfig eth0 | awk '/HWaddr/{p //wrong line 1 3 2 treebear SW 0 0% 7% [ksoftirqd/0] 1930 1870 treebear S 37412 15% 2% /usr/bin/ppcloud 24289 6786 treebear R 1512 1% 2% top 1815 1 treebear S 4032 2% 0% /usr/sbin/lighttpd -f /etc/lighttpd/l 15051 1815 treebear S 3320 1% 0% {luci} /usr/bin/lua /www/cgi-bin/luci //wrong line 3 1202 1 treebear S 1544 1% 0% /sbin/netifd 1165 1 treebear S 1528 1% 0% /sbin/syslogd -l 7 -O /etc/log/system 1833 1819 treebear S 1520 1% 0% {update_cur_stat} /bin/sh /usr/sbin/u 6786 1745 treebear S 1520 1% 0% -ash 15120 15051 treebear S 1512 1% 0% sh -c ifconfig eth0 | awk '/HWaddr/{p //wrong line 2 1745 1 treebear S 1508 1% 0% /usr/sbin/telnetd 1911 1 treebear S 1508 1% 0% /usr/sbin/crond start 1353 1202 treebear S 1508 1% 0% udhcpc -R -p /var/run/udhcpc-eth0.5.p 1791 1 treebear S 1508 1% 0% /usr/sbin/ntpd -n -u 86400 -r 600 -p 1870 1 treebear S 1508 1% 0% {witownapp.sh} /bin/sh /usr/sbin/wito 1164 1 treebear S 1504 1% 0% /sbin/klogd 1819 1 treebear S 1504 1% 0% {runing_status_m} /bin/sh /usr/sbin/r 24282 1833 treebear S 1500 1% 0% sleep 10 1 0 treebear S 1360 1% 0% /sbin/procd

wrong line 3 is blocked by wrong line 2 and wrong line 2 is blocked by wrong line 1.

Hopes for your reply soon. Thanks a lot.