[FS#206] zram-swap causes random application crashes

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Martin Tippmann (glycoknob) 

Attached to Project - LEDE Project
Summary - zram-swap causes random application crashes
Task Type - Bug Report
Category - Kernel
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - Using zram swap reliably causes application crashes. The issue seems to be older and already exists in Chaos Calmer

see https://dev.openwrt.org/ticket/21705 
and https://github.com/weimarnetz/weimarnetz/issues/251

The issue is still there with current trunk as of today. 

To reproduce: Enable zram-swap, printk and crash-logging and use the router e.g. luci - you will see random crashes appear. 



Mon Oct  3 22:43:45 2016 kern.info kernel: 
Mon Oct  3 22:43:45 2016 kern.info kernel: do_page_fault(): sending SIGSEGV to luci for invalid write access to 000083e0
Mon Oct  3 22:43:45 2016 kern.info kernel: epc = 77107d64 in libc.so[770e0000+90000]
Mon Oct  3 22:43:45 2016 kern.info kernel: ra  = 77107e74 in libc.so[770e0000+90000]
Mon Oct  3 22:43:45 2016 kern.info kernel: 
Mon Oct  3 22:43:51 2016 daemon.info dnsmasq-dhcp[1870]: DHCPREQUEST(wlan1-1) 10.63.192.11 90:68:c3:aa:b4:80 
Mon Oct  3 22:43:51 2016 daemon.info dnsmasq-dhcp[1870]: DHCPACK(wlan1-1) 10.63.192.11 90:68:c3:aa:b4:80 android-220e348d812bc28f
Mon Oct  3 22:44:10 2016 kern.info kernel: 
Mon Oct  3 22:44:10 2016 kern.info kernel: do_page_fault(): sending SIGSEGV to luci for invalid read access from 0000c138
Mon Oct  3 22:44:10 2016 kern.info kernel: epc = 770a7b37 in liblua.so.5.1.5[7709a000+2e000]
Mon Oct  3 22:44:10 2016 kern.info kernel: ra  = 770a7ad9 in liblua.so.5.1.5[7709a000+2e000]
Mon Oct  3 22:44:10 2016 kern.info kernel: 
Mon Oct  3 22:48:57 2016 daemon.info dnsmasq-dhcp[1870]: DHCPREQUEST(wlan1-1) 10.63.192.12 e8:de:27:19:b9:17 
Mon Oct  3 22:48:57 2016 daemon.info dnsmasq-dhcp[1870]: DHCPACK(wlan1-1) 10.63.192.12 e8:de:27:19:b9:17 zeno
Mon Oct  3 23:03:30 2016 kern.info kernel: 
Mon Oct  3 23:03:30 2016 kern.info kernel: do_page_fault(): sending SIGSEGV to luci for invalid write access to 0000c1b0
Mon Oct  3 23:03:30 2016 kern.info kernel: epc = 771d3d64 in libc.so[771ac000+90000]
Mon Oct  3 23:03:30 2016 kern.info kernel: ra  = 771d403c in libc.so[771ac000+90000]
Mon Oct  3 23:03:30 2016 kern.info kernel: 
Mon Oct  3 23:13:14 2016 daemon.info hostapd: wlan1-1: STA 90:68:c3:aa:b4:80 IEEE 802.11: disassociated due to inactivity
Mon Oct  3 23:13:15 2016 daemon.info hostapd: wlan1-1: STA 90:68:c3:aa:b4:80 IEEE 802.11: deauthenticated due to inactivity (timer DEAUTH/REMOVE)
Mon Oct  3 23:14:05 2016 daemon.info dnsmasq-dhcp[1870]: DHCPREQUEST(wlan1-1) 10.63.192.12 e8:de:27:19:b9:17 
Mon Oct  3 23:14:05 2016 daemon.info dnsmasq-dhcp[1870]: DHCPACK(wlan1-1) 10.63.192.12 e8:de:27:19:b9:17 zeno
Mon Oct  3 23:19:00 2016 kern.info kernel: 
Mon Oct  3 23:19:00 2016 kern.info kernel: do_page_fault(): sending SIGSEGV to luci for invalid read access from 00000288
Mon Oct  3 23:19:00 2016 kern.info kernel: epc = 77810c23 in libjson-c.so.2.0.2[7780c000+16000]
Mon Oct  3 23:19:00 2016 kern.info kernel: ra  = 77810bf5 in libjson-c.so.2.0.2[7780c000+16000]
Mon Oct  3 23:19:00 2016 kern.info kernel: 


More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=206