One of the problems I see with this kind of reflection is that one hash could have more than one name if you create aliases using GLOBs:

my *otherName = %hash1;
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If you pay the maximum attention, you could pass the name of the hash as a scalar string, then use eval variable name dereferencing (like %$name, as pointed out below by others) inside check_limit to access the actual hash. Did I already say that you have to carefully check every implication of such an approach?

Update: I realised that eval is overkill in this case, a simple %$name will do as suggested by others. Nonetheless, this must not be an excuse to drop a careful approach.