DISEASE CHARACTERISTICS: Histologically or cytologically confirmed resectable primary hepatocellular carcinoma or cholangiocarcinoma No metastatic disease outside of the liver

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life expectancy: Not specified Hematopoietic: Absolute neutrophil count greater than 1,500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 9 g/dL Hepatic: Bilirubin no greater than 2 times upper limit of normal (ULN) SGOT or SGPT no greater than 5 times ULN Albumin at least 2.5 g/dL INR less than 1.3 Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: QTc prolongation no greater than 440 msec Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective barrier contraception No malabsorption or other gastrointestinal (GI) condition that would preclude ability to take oral medication and/or GI absorption (e.g., partial small bowel obstruction) No non-malignant systemic disease that would preclude study No active uncontrolled infection No grade II nausea or grade I vomiting despite antiemetic medication

PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent immunotherapy Chemotherapy: No other concurrent chemotherapy Endocrine therapy: No concurrent hormonal therapy including estrogen therapy No concurrent oral contraceptives or other hormonal methods Concurrent megestrol acetate allowed No concurrent corticosteroids (except for nausea/vomiting during gemcitabine administration) Radiotherapy: At least 6 weeks since prior radiotherapy and recovered No concurrent radiotherapy Surgery: See Disease Characteristics At least 6 weeks since prior surgery and recovered Other: At least 6 weeks since prior systemic therapy and recovered No concurrent CYP3A4 inhibitors or inducers including: Azoles (e.g., itraconazole, clotrimazole, fluconazole, or ketoconazole) Macrolide antibiotics (e.g., azithromycin, clarithromycin, or erythromycin) Cyclosporine Grapefruit Antiepileptic medication (e.g., phenytoin, carbamazepine, or phenobarbital) Antibiotics for tuberculosis (e.g., rifampin or isoniazid) No concurrent HIV protease inhibitors (e.g., amprenavir, ritonavir, or saquinavir mesylate) No concurrent cisapride No other concurrent investigational therapy