I have shares of a company I got from exercising before the company went public. Some shares I've held for less than a year, some for more. I exercised all the options after holding them for a year.

I transferred them to a brokerage, but they don't have any cost basis or lot information; they're all the same as far as the brokerage is concerned.

If I sell the shares I've held for over a year and report it correctly, will I get long-term capital gains, or is there a reporting or bookkeeping requirement on the brokerage's end that will cause a problem?