target/riscv: Set env->bins in gen_exception_illegal

While we set env->bins when unwinding for ILLEGAL_INST,
from e.g. csrrw, we weren't setting it for immediately
illegal instructions.

Add a testcase for mtval via both exception paths.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1060
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220604231004.49990-2-richard.henderson@linaro.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/translate.c

@@ -240,6 +240,8 @@ static void generate_exception_mtval(DisasContext *ctx, int excp)
 
 static void gen_exception_illegal(DisasContext *ctx)
 {
+    tcg_gen_st_i32(tcg_constant_i32(ctx->opcode), cpu_env,
+                   offsetof(CPURISCVState, bins));
     generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
 }
 

tests/tcg/riscv64/Makefile.softmmu-target

@@ -0,0 +1,21 @@
+#
+# RISC-V system tests
+#
+
+TEST_SRC = $(SRC_PATH)/tests/tcg/riscv64
+VPATH += $(TEST_SRC)
+
+LINK_SCRIPT = $(TEST_SRC)/semihost.ld
+LDFLAGS = -T $(LINK_SCRIPT)
+CFLAGS += -g -Og
+
+%.o: %.S
+	$(CC) $(CFLAGS) $< -c -o $@
+%: %.o $(LINK_SCRIPT)
+	$(LD) $(LDFLAGS) $< -o $@
+
+QEMU_OPTS += -M virt -display none -semihosting -device loader,file=
+
+EXTRA_RUNS += run-issue1060
+run-issue1060: issue1060
+	$(call run-test, $<, $(QEMU) $(QEMU_OPTS)$<)

tests/tcg/riscv64/issue1060.S

@@ -0,0 +1,53 @@
+	.option	norvc
+
+	.text
+	.global _start
+_start:
+	lla	t0, trap
+	csrw	mtvec, t0
+
+	# These are all illegal instructions
+	csrw	time, x0
+	.insn	i CUSTOM_0, 0, x0, x0, 0x321
+	csrw	time, x0
+	.insn	i CUSTOM_0, 0, x0, x0, 0x123
+	csrw	cycle, x0
+
+	# Success!
+	li	a0, 0
+	j	_exit
+
+trap:
+	# When an instruction traps, compare it to the insn in memory.
+	csrr	t0, mepc
+	csrr	t1, mtval
+	lwu	t2, 0(t0)
+	bne	t1, t2, fail
+
+	# Skip the insn and continue.
+	addi	t0, t0, 4
+	csrw	mepc, t0
+	mret
+
+fail:
+	li	a0, 1
+
+# Exit code in a0
+_exit:
+	lla	a1, semiargs
+	li	t0, 0x20026	# ADP_Stopped_ApplicationExit
+	sd	t0, 0(a1)
+	sd	a0, 8(a1)
+	li	a0, 0x20	# TARGET_SYS_EXIT_EXTENDED
+
+	# Semihosting call sequence
+	.balign	16
+	slli	zero, zero, 0x1f
+	ebreak
+	srai	zero, zero, 0x7
+	j	.
+
+	.data
+	.balign	16
+semiargs:
+	.space	16

tests/tcg/riscv64/semihost.ld

@@ -0,0 +1,21 @@
+ENTRY(_start)
+
+SECTIONS
+{
+    /* virt machine, RAM starts at 2gb */
+    . = 0x80000000;
+    .text : {
+        *(.text)
+    }
+    .rodata : {
+        *(.rodata)
+    }
+    /* align r/w section to next 2mb */
+    . = ALIGN(1 << 21);
+    .data : {
+        *(.data)
+    }
+    .bss : {
+        *(.bss)
+    }
+}