In this paper, we propose ReDRAM, as a reconfigurable DRAM-based processing-in-memory (PIM) accelerator, which transforms current DRAM architecture to massively parallel computational units exploiting the high internal bandwidth of modern memory chips. ReDRAM uses the analog operation of DRAM sub-arrays and elevates it to implement a full set of 1- and 2-input bulk bit-wise operations (NOT, (N)AND, (N)OR, and even X(N)OR) between operands stored in the same bit-line, based on a new dual-row activation mechanism with a modest change to peripheral circuits such sense amplifiers. ReDRAM can be leveraged to greatly reduce energy consumption and latency of complex in-DRAM logic computations relying on state-of-the-art mechanisms based on triple-row activation, dual-contact cells, row initialization, NOR style, etc. The extensive circuit-architecture simulations show that ReDRAM achieves on average 54× and 7.1× higher throughput for performing bulk bit-wise operations compared with CPU and GPU, respectively. Besides, ReDRAM outperforms recent processing-in-DRAM platforms with up to 3.7× better performance.