linux/arch/riscv/kernel/probes/decode-insn.c
Chen Lifu 67979e927d
riscv: kprobes: implement the branch instructions
This has been tested by probing a module that contains each of the
flavors of branches we have.

Signed-off-by: Chen Lifu <chenlifu@huawei.com>
[Palmer: commit message, fix kconfig errors]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-21 23:22:34 -07:00

48 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <asm/sections.h>
#include "decode-insn.h"
#include "simulate-insn.h"
/* Return:
* INSN_REJECTED If instruction is one not allowed to kprobe,
* INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
*/
enum probe_insn __kprobes
riscv_probe_decode_insn(probe_opcode_t *addr, struct arch_probe_insn *api)
{
probe_opcode_t insn = *addr;
/*
* Reject instructions list:
*/
RISCV_INSN_REJECTED(system, insn);
RISCV_INSN_REJECTED(fence, insn);
/*
* Simulate instructions list:
* TODO: the REJECTED ones below need to be implemented
*/
#ifdef CONFIG_RISCV_ISA_C
RISCV_INSN_REJECTED(c_j, insn);
RISCV_INSN_REJECTED(c_jr, insn);
RISCV_INSN_REJECTED(c_jal, insn);
RISCV_INSN_REJECTED(c_jalr, insn);
RISCV_INSN_REJECTED(c_beqz, insn);
RISCV_INSN_REJECTED(c_bnez, insn);
RISCV_INSN_REJECTED(c_ebreak, insn);
#endif
RISCV_INSN_SET_SIMULATE(jal, insn);
RISCV_INSN_SET_SIMULATE(jalr, insn);
RISCV_INSN_SET_SIMULATE(auipc, insn);
RISCV_INSN_SET_SIMULATE(branch, insn);
return INSN_GOOD;
}