➜ ~ xmodmap
xmodmap: up to 3 keys per modifier, (keycodes in parentheses):
shift Shift_L (0x32), Shift_R (0x3e)
lock Caps_Lock (0x42)
control Control_L (0x25), Control_R (0x69)
mod1 Alt_L (0x40), Alt_R (0x6c), Meta_L (0xcd)
mod2 Num_Lock (0x4d)
mod3
mod4 Super_L (0x85), Super_L (0xce), Hyper_L (0xcf)
mod5 ISO_Level3_Shift (0x5c), Mode_switch (0xcb)
Copy current xmodmap config:
xmodmap -pke > ~/.xmodmap
Do its backup just in case
cp ~/.xmodmap ~/.xmodmap.bak
Drop Super_L from mod4:
xmodmap -e "remove mod4 = Super_L"
And add it to Control:
xmodmap -e "add Control = Super_L"
As a result:
➜ ~ xmodmap
xmodmap: up to 4 keys per modifier, (keycodes in parentheses):
shift Shift_L (0x32), Shift_R (0x3e)
lock Caps_Lock (0x42)
control Control_L (0x25), Control_R (0x69), Super_L (0x85), Super_L (0xce)
mod1 Alt_L (0x40), Alt_R (0x6c), Meta_L (0xcd)
mod2 Num_Lock (0x4d)
mod3
mod4 Hyper_L (0xcf)
mod5 ISO_Level3_Shift (0x5c), Mode_switch (0xcb)
After this your Super_L button will work as Control.
Don’t forget to update .xmodmap config in your $HOME folder:
xmodmap -pke > ~/.xmodmap