From edb05a43b9991fba471eb79433aea01f7e1142c7 Mon Sep 17 00:00:00 2001
From: Sleigh-InSPECtor <166091708+Sleigh-InSPECtor@users.noreply.github.com>
Date: Wed, 15 May 2024 16:17:17 +0930
Subject: [PATCH] riscv: handle divideby0

---
 .../Processors/RISCV/data/languages/riscv.rv32m.sinc   | 10 ++++++++++
 .../Processors/RISCV/data/languages/riscv.rv64m.sinc   |  4 ++++
 2 files changed, 14 insertions(+)

diff --git a/Ghidra/Processors/RISCV/data/languages/riscv.rv32m.sinc b/Ghidra/Processors/RISCV/data/languages/riscv.rv32m.sinc
index f7202a39f4..07bb6e80fe 100644
--- a/Ghidra/Processors/RISCV/data/languages/riscv.rv32m.sinc
+++ b/Ghidra/Processors/RISCV/data/languages/riscv.rv32m.sinc
@@ -1,8 +1,15 @@
 # RV32M Standard Extension
+macro checkDivByZero(reg, rd, adjustment) {
+	if (reg != 0) goto <NOTZERO>;
+	rd = adjustment;
+	goto inst_next;
+	<NOTZERO>
+}
 
 # div d,s,t 02004033 fe00707f SIMPLE (0, 0) 
 :div rd,rs1,rs2 is rs1 & rs2 & rd & op0001=0x3 & op0204=0x4 & op0506=0x1 & funct3=0x4 & funct7=0x1
 {
+	checkDivByZero(rs2, rd, ~0);
 	rd = rs1 s/ rs2;
 }
 
@@ -10,6 +17,7 @@
 # divu d,s,t 02005033 fe00707f SIMPLE (0, 0) 
 :divu rd,rs1,rs2 is rs1 & rs2 & rd & op0001=0x3 & op0204=0x4 & op0506=0x1 & funct3=0x5 & funct7=0x1
 {
+	checkDivByZero(rs2, rd, ~0);
 	rd = rs1 / rs2;
 }
 
@@ -54,6 +62,7 @@
 # rem d,s,t 02006033 fe00707f SIMPLE (0, 0) 
 :rem rd,rs1,rs2 is rs1 & rs2 & rd & op0001=0x3 & op0204=0x4 & op0506=0x1 & funct3=0x6 & funct7=0x1
 {
+	checkDivByZero(rs2, rd, rs1);
 	rd = rs1 s% rs2;
 }
 
@@ -61,5 +70,6 @@
 # remu d,s,t 02007033 fe00707f SIMPLE (0, 0) 
 :remu rd,rs1,rs2 is rs1 & rs2 & rd & op0001=0x3 & op0204=0x4 & op0506=0x1 & funct3=0x7 & funct7=0x1
 {
+	checkDivByZero(rs2, rd, rs1);
 	rd = rs1 % rs2;
 }
diff --git a/Ghidra/Processors/RISCV/data/languages/riscv.rv64m.sinc b/Ghidra/Processors/RISCV/data/languages/riscv.rv64m.sinc
index 8da116d62e..50fc2cda78 100644
--- a/Ghidra/Processors/RISCV/data/languages/riscv.rv64m.sinc
+++ b/Ghidra/Processors/RISCV/data/languages/riscv.rv64m.sinc
@@ -5,6 +5,7 @@
 {
 	local tmpr1:4 = rs1:4;
 	local tmpr2:4 = rs2:4;
+	checkDivByZero(tmpr2, rd, ~0);
 	rd = sext(tmpr1 / tmpr2);
 }
 
@@ -14,6 +15,7 @@
 {
 	local tmpr1:4 = rs1:4;
 	local tmpr2:4 = rs2:4;
+	checkDivByZero(tmpr2, rd, ~0);
 	rd = sext(tmpr1 s/ tmpr2);
 }
 
@@ -31,6 +33,7 @@
 {
 	local tmpr1:4 = rs1:4;
 	local tmpr2:4 = rs2:4;
+	checkDivByZero(tmpr2, rd, sext(tmpr1));
 	rd = sext(tmpr1 % tmpr2);
 }
 
@@ -40,5 +43,6 @@
 {
 	local tmpr1:4 = rs1:4;
 	local tmpr2:4 = rs2:4;
+	checkDivByZero(tmpr2, rd, sext(tmpr1));
 	rd = sext(tmpr1 s% tmpr2);
 }