1 files changed, 48 insertions, 0 deletions
diff --git a/arch/riscv/kernel/probes/decode-insn.c b/arch/riscv/kernel/probes/decode-insn.c
new file mode 100644
index 0000000000..65d9590bfb
--- /dev/null
+++ b/arch/riscv/kernel/probes/decode-insn.c
@@ -0,0 +1,48 @@
+// 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_jal,		insn);
+	RISCV_INSN_REJECTED(c_ebreak,		insn);
+
+	RISCV_INSN_SET_SIMULATE(c_j,		insn);
+	RISCV_INSN_SET_SIMULATE(c_jr,		insn);
+	RISCV_INSN_SET_SIMULATE(c_jalr,		insn);
+	RISCV_INSN_SET_SIMULATE(c_beqz,		insn);
+	RISCV_INSN_SET_SIMULATE(c_bnez,		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;
+}