SA_IMMUTABLE and the hazards of messing with signals

> I think some effort on your side would need to happen both initially to drive it then there's an ongoing maintenance commitment.

I'm sure you're right about this too. Unfortunately I'm not confident the expected value *for us* of doing this would actually be greater than what we're currently doing; we could easily do a bunch of work and then the CI test failures end up being ignored (unless we do the work to diagnose and chase down each regression, which is not all that different from what we have to do today). At a less rational level, it grates to be a tiny, unpaid team doing work to clean up the messes of people being paid megabucks to do kernel development; this is already the case, but upping the stakes in the hope of a net win makes it more so.