[PATCH 01/11] riscv: kprobes: Move branch_rs2_idx to insn.h

Nam Cao namcao at linutronix.de
Sun May 11 14:17:53 PDT 2025


Similar to other instruction-processing macros/functions, branch_rs2_idx
should be in insn.h.

Move it into insn.h as RV_EXTRACT_RS2_REG. This new name matches the style
in insn.h.

Signed-off-by: Nam Cao <namcao at linutronix.de>
---
 arch/riscv/include/asm/insn.h            | 5 +++++
 arch/riscv/kernel/probes/simulate-insn.c | 5 +----
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/include/asm/insn.h b/arch/riscv/include/asm/insn.h
index 09fde95a5e8f..debac13a3476 100644
--- a/arch/riscv/include/asm/insn.h
+++ b/arch/riscv/include/asm/insn.h
@@ -64,6 +64,7 @@
 #define RVG_RS2_OPOFF		20
 #define RVG_RD_OPOFF		7
 #define RVG_RS1_MASK		GENMASK(4, 0)
+#define RVG_RS2_MASK		GENMASK(4, 0)
 #define RVG_RD_MASK		GENMASK(4, 0)
 
 /* The bit field of immediate value in RVC J instruction */
@@ -295,6 +296,10 @@ static __always_inline bool riscv_insn_is_c_jalr(u32 code)
 	({typeof(x) x_ = (x); \
 	(RV_X(x_, RVG_RS1_OPOFF, RVG_RS1_MASK)); })
 
+#define RV_EXTRACT_RS2_REG(x) \
+	({typeof(x) x_ = (x); \
+	(RV_X(x_, RVG_RS2_OPOFF, RVG_RS2_MASK)); })
+
 #define RV_EXTRACT_RD_REG(x) \
 	({typeof(x) x_ = (x); \
 	(RV_X(x_, RVG_RD_OPOFF, RVG_RD_MASK)); })
diff --git a/arch/riscv/kernel/probes/simulate-insn.c b/arch/riscv/kernel/probes/simulate-insn.c
index 6c166029079c..77be381bb8b4 100644
--- a/arch/riscv/kernel/probes/simulate-insn.c
+++ b/arch/riscv/kernel/probes/simulate-insn.c
@@ -121,9 +121,6 @@ bool __kprobes simulate_auipc(u32 opcode, unsigned long addr, struct pt_regs *re
 #define branch_rs1_idx(opcode) \
 	(((opcode) >> 15) & 0x1f)
 
-#define branch_rs2_idx(opcode) \
-	(((opcode) >> 20) & 0x1f)
-
 #define branch_funct3(opcode) \
 	(((opcode) >> 12) & 0x7)
 
@@ -157,7 +154,7 @@ bool __kprobes simulate_branch(u32 opcode, unsigned long addr, struct pt_regs *r
 	unsigned long rs2_val;
 
 	if (!rv_insn_reg_get_val(regs, branch_rs1_idx(opcode), &rs1_val) ||
-	    !rv_insn_reg_get_val(regs, branch_rs2_idx(opcode), &rs2_val))
+	    !rv_insn_reg_get_val(regs, RV_EXTRACT_RS2_REG(opcode), &rs2_val))
 		return false;
 
 	offset_tmp = branch_offset(opcode);
-- 
2.39.5




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