Re: Maintaining Service Program signatures

On 2/19/13 1:48 PM, Alan Campin wrote:

I am strongly opposed to the idea of using fixed signatures. It is the
equivalent to turning off level checks on a table. Just playing Russian
Roulette. Eventually you are going to blow out your brains.

Signatures exist for a reason.

Yes, they do. Which is why you need to know exactly what you're doing when you change a service program's interface, and why, when using fixed signatures, and you do anything with the sequence of entry points other than tack new ones onto the end, you need to invalidate any fixed signatures that denote no-longer-valid entry point sequences.

But the option of using one or more fixed signatures also exists for a reason. If you add or remove entry points without using fixed signatures, then anything that uses the service program is going to break if it's not re-linked to the new version, even if the change doesn't invalidate the old entry point sequence, and when it throws the signature violation, you might not be around to pick up the pieces.

Either way, you need to know what you're doing.

--
JHHL