| // SPDX-License-Identifier: GPL-2.0+ |
| |
| #include <linux/bitops.h> |
| #include <linux/kernel.h> |
| #include <linux/kprobes.h> |
| |
| #include "decode-insn.h" |
| #include "simulate-insn.h" |
| |
| static inline bool rv_insn_reg_get_val(struct pt_regs *regs, u32 index, |
| unsigned long *ptr) |
| { |
| if (index == 0) |
| *ptr = 0; |
| else if (index <= 31) |
| *ptr = *((unsigned long *)regs + index); |
| else |
| return false; |
| |
| return true; |
| } |
| |
| static inline bool rv_insn_reg_set_val(struct pt_regs *regs, u32 index, |
| unsigned long val) |
| { |
| if (index == 0) |
| return false; |
| else if (index <= 31) |
| *((unsigned long *)regs + index) = val; |
| else |
| return false; |
| |
| return true; |
| } |
| |
| bool __kprobes simulate_jal(u32 opcode, unsigned long addr, struct pt_regs *regs) |
| { |
| /* |
| * 31 30 21 20 19 12 11 7 6 0 |
| * imm [20] | imm[10:1] | imm[11] | imm[19:12] | rd | opcode |
| * 1 10 1 8 5 JAL/J |
| */ |
| bool ret; |
| u32 imm; |
| u32 index = (opcode >> 7) & 0x1f; |
| |
| ret = rv_insn_reg_set_val(regs, index, addr + 4); |
| if (!ret) |
| return ret; |
| |
| imm = ((opcode >> 21) & 0x3ff) << 1; |
| imm |= ((opcode >> 20) & 0x1) << 11; |
| imm |= ((opcode >> 12) & 0xff) << 12; |
| imm |= ((opcode >> 31) & 0x1) << 20; |
| |
| instruction_pointer_set(regs, addr + sign_extend32((imm), 20)); |
| |
| return ret; |
| } |
| |
| bool __kprobes simulate_jalr(u32 opcode, unsigned long addr, struct pt_regs *regs) |
| { |
| /* |
| * 31 20 19 15 14 12 11 7 6 0 |
| * offset[11:0] | rs1 | 010 | rd | opcode |
| * 12 5 3 5 JALR/JR |
| */ |
| bool ret; |
| unsigned long base_addr; |
| u32 imm = (opcode >> 20) & 0xfff; |
| u32 rd_index = (opcode >> 7) & 0x1f; |
| u32 rs1_index = (opcode >> 15) & 0x1f; |
| |
| ret = rv_insn_reg_set_val(regs, rd_index, addr + 4); |
| if (!ret) |
| return ret; |
| |
| ret = rv_insn_reg_get_val(regs, rs1_index, &base_addr); |
| if (!ret) |
| return ret; |
| |
| instruction_pointer_set(regs, (base_addr + sign_extend32((imm), 11))&~1); |
| |
| return ret; |
| } |