This is what I found,
http://www.theatreontario.org/theatresafety/downloads/v_firearms-blades.pdf There are no federal laws concerning the lengths of knives allowed. However there are many informal
"blade length rules" in Canada. These vary from 3" to 4" for folding knives in various areas around the
country, depending on what differentiates a pocket-knife from a fighting knife to the police. There are no
federal laws about knife materials, as well there are no formal laws on serrations, or dual edged blades.
So as long as it's not concealed it seems to be up to the RCMP as to what a fighting knife is.