security_secctx_to_secid question

[Mr Dash Four]

One simple query: the above function (from include/linux/security.h) 
maps the specified security context to a number. Are there any instances 
where this number would change while the kernel is still running? I am 
aware that the number *might* change on kernel reboot, but need to know 
if this number is likely to change if that is not the case.

In other words, if I use the above function to get a specific security 
context mapped to a number and later on, say after a month, I try to 
retrieve that same security context (assuming the kernel has been 
running continuously in that period) what is the likelihood that I will 
get a different number? Thanks!