Remove stackoverflow error, have one CORE_INTERNAL error for catastrophic crash

apps/makefile.common

@@ -1,8 +1,9 @@
 PREFIX:=riscv64-elf-
+OPT ?= -Os
 CFLAGS+=-I${TOPDIR}/common
 CFLAGS+=-fno-stack-protector
 CFLAGS+=-static-libgcc -fdata-sections -ffunction-sections
-CFLAGS+=-g -Os -march=rv32im -mabi=ilp32 -static
+CFLAGS+=-g ${OPT} -march=rv32im -mabi=ilp32 -static
 LDFLAGS:= -T ${TOPDIR}/apps/linker.ld -nostdlib -Wl,--gc-sections
 LIBS:= -lgcc # needed for softfp
 
@@ -21,8 +22,8 @@ else
 endif
 
 all_common:
-	${PREFIX}gcc -o ${PROJECT}.elf ${CFLAGS} ${LDFLAGS} ${SRCS} ${LIBS}
+	@${PREFIX}gcc -o ${PROJECT}.elf ${CFLAGS} ${LDFLAGS} ${SRCS} ${LIBS}
-	$(PREFIX)objcopy ${PROJECT}.elf -O binary ${PROJECT}.bin
+	@$(PREFIX)objcopy ${PROJECT}.elf -O binary ${PROJECT}.bin
 
 disasm_common: all
 	$(PREFIX)objdump -S -d -f ${PROJECT}.elf

test/Makefile

@@ -1,5 +1,8 @@
 all:
-	make -C example_1
+	@make -C example_1
+	@make -C stackoverflow
 
 clean:
 	make -C example_1 clean
+	make -C stackoverflow clean
+

test/example_1/Makefile

@@ -17,15 +17,15 @@ INC_DIRS=-I$(UNITY_ROOT)/src -I../../uvm32/ -I../../common -Irom
 .PHONY: rom
 
 default: $(SRC_FILES1) rom
-	$(C_COMPILER) $(CFLAGS) $(INC_DIRS) $(SYMBOLS) $(SRC_FILES1) rom/rom-header.c -o $(TARGET1)
+	@$(C_COMPILER) $(CFLAGS) $(INC_DIRS) $(SYMBOLS) $(SRC_FILES1) rom/rom-header.c -o $(TARGET1)
-	- ./$(TARGET1)
+	@- ./$(TARGET1)
 
 rom:
-	(cd rom && make)
+	@(cd rom && make)
 
 test/test_runners/${SUITE_NAME}_Runner.c: test/${SUITE_NAME}.c
-	mkdir -p test/test_runners
+	@mkdir -p test/test_runners
-	ruby $(UNITY_ROOT)/auto/generate_test_runner.rb test/${SUITE_NAME}.c  test/test_runners/${SUITE_NAME}_Runner.c
+	@ruby $(UNITY_ROOT)/auto/generate_test_runner.rb test/${SUITE_NAME}.c  test/test_runners/${SUITE_NAME}_Runner.c
 
 clean:
 	rm -rf $(TARGET1) test/test_runners

test/example_1/rom/Makefile

@@ -2,9 +2,9 @@ TOPDIR=../../../
 PROJECT:=$(shell basename ${PWD})
 SRCS=${PROJECT}.c ${TOPDIR}/apps/crt0.S
 all: all_common
-	# Convert ROM to C file and header
+	@# Convert ROM to C file and header
-	xxd -i ${PROJECT}.bin > ${PROJECT}-header.c
+	@xxd -i ${PROJECT}.bin > ${PROJECT}-header.c
-	echo "extern unsigned char ${PROJECT}_bin[]; extern int ${PROJECT}_bin_len;" > ${PROJECT}-header.h
+	@echo "extern unsigned char ${PROJECT}_bin[]; extern int ${PROJECT}_bin_len;" > ${PROJECT}-header.h
 
 test: test_common
 clean: clean_common

test/stackoverflow/Makefile

@@ -0,0 +1,33 @@
+C_COMPILER=gcc
+
+UNITY_ROOT=../unity
+
+CFLAGS=-std=c99
+CFLAGS += -Wall
+CFLAGS += -Werror
+CFLAGS += -DUVM32_MEMORY_SIZE=512
+
+SUITE_NAME=tests
+
+TARGET_BASE1=test1
+TARGET1 = $(TARGET_BASE1)
+SRC_FILES1=$(UNITY_ROOT)/src/unity.c test/${SUITE_NAME}.c  test/test_runners/${SUITE_NAME}_Runner.c ../../uvm32/uvm32.c
+INC_DIRS=-I$(UNITY_ROOT)/src -I../../uvm32/ -I../../common -Irom
+
+.PHONY: rom
+
+default: $(SRC_FILES1) rom
+	@$(C_COMPILER) $(CFLAGS) $(INC_DIRS) $(SYMBOLS) $(SRC_FILES1) rom/rom-header.c -o $(TARGET1)
+	@- ./$(TARGET1)
+
+rom:
+	@(cd rom && make)
+
+test/test_runners/${SUITE_NAME}_Runner.c: test/${SUITE_NAME}.c
+	@mkdir -p test/test_runners
+	@ruby $(UNITY_ROOT)/auto/generate_test_runner.rb test/${SUITE_NAME}.c  test/test_runners/${SUITE_NAME}_Runner.c
+
+clean:
+	rm -rf $(TARGET1) test/test_runners
+	(cd rom && make clean)
+

test/stackoverflow/rom/Makefile

@@ -0,0 +1,14 @@
+TOPDIR=../../../
+PROJECT:=$(shell basename ${PWD})
+SRCS=${PROJECT}.c ${TOPDIR}/apps/crt0.S
+OPT=-O0 # don't optimise
+all: all_common
+	@# Convert ROM to C file and header
+	@xxd -i ${PROJECT}.bin > ${PROJECT}-header.c
+	@echo "extern unsigned char ${PROJECT}_bin[]; extern int ${PROJECT}_bin_len;" > ${PROJECT}-header.h
+
+test: test_common
+clean: clean_common
+	rm -f ${PROJECT}-header.h ${PROJECT}-header.c
+
+include ${TOPDIR}/apps/makefile.common

test/stackoverflow/rom/rom.c

@@ -0,0 +1,12 @@
+#include "uvm32_target.h"
+
+int foo(int a) {
+    yield(0);
+    printdec(a);
+    return foo(a+1);
+}
+
+void main(void) {
+    foo(1);
+}
+

test/stackoverflow/test/tests.c

@@ -0,0 +1,34 @@
+#include <string.h>
+#include "unity.h"
+#include "uvm32.h"
+#include "../common/uvm32_common_custom.h"
+
+#include "rom-header.h"
+
+static uvm32_state_t vmst;
+static uvm32_evt_t evt;
+
+void setUp(void) {
+    // runs before each test
+    uvm32_init(&vmst);
+    uvm32_load(&vmst, rom_bin, rom_bin_len);
+}
+
+void tearDown(void) {
+}
+
+void test_stackoverflow(void) {
+    // run the vm
+    while(1) {
+        uvm32_run(&vmst, &evt, 100);
+        if (evt.typ == UVM32_EVT_SYSCALL) {
+            // ignore syscalls
+        } else {
+            TEST_ASSERT_EQUAL(UVM32_EVT_ERR, evt.typ);
+            TEST_ASSERT_EQUAL(UVM32_ERR_INTERNAL_CORE, evt.data.err.errcode);
+            break;
+        }
+    }
+}
+
+

uvm32/uvm32.c

@@ -141,7 +141,7 @@ uint32_t uvm32_run(uvm32_state_t *vmst, uvm32_evt_t *evt, uint32_t instr_meter)
     uint32_t num_instr = 0;
 
     if (vmst->stack_canary != UVM32_NULL && *vmst->stack_canary != STACK_CANARY_VALUE) {
-        setStatusErr(vmst, UVM32_ERR_STACKOVERFLOW);
+        setStatusErr(vmst, UVM32_ERR_INTERNAL_CORE);
         setup_err_evt(vmst, evt);
         return num_instr;
     }
@@ -159,50 +159,58 @@ uint32_t uvm32_run(uvm32_state_t *vmst, uvm32_evt_t *evt, uint32_t instr_meter)
         uint64_t elapsedUs = 1;
         uint32_t ret;
         ret = MiniRV32IMAStep(vmst, &vmst->core, vmst->memory, 0, elapsedUs, 1);
-        if (3 == ret) {
+    
-            // Fetch registers used by syscall
+        switch(ret) {
-            const uint32_t syscall = vmst->core.regs[17];  // a7
+            case 0:  // ok
-            // on exception we should jump to mtvec, but we handle directly
+            break;
-            // and skip over the ecall instruction
+            case 12: { // ecall
-            vmst->core.pc += 4;
+                // Fetch registers used by syscall
-            switch(syscall) {
+                const uint32_t syscall = vmst->core.regs[17];  // a7
-                // inbuilt syscalls
+                // on exception we should jump to mtvec, but we handle directly
-                 case UVM32_SYSCALL_HALT:
+                // and skip over the ecall instruction
-                    setStatus(vmst, UVM32_STATUS_ENDED);
+                vmst->core.pc += 4;
-                break;
+                switch(syscall) {
-                case UVM32_SYSCALL_STACKPROTECT: {
+                    // inbuilt syscalls
-                    // don't allow errant code to change it once set
+                     case UVM32_SYSCALL_HALT:
-                    if (vmst->stack_canary == (uint8_t *)UVM32_NULL) {
+                        setStatus(vmst, UVM32_STATUS_ENDED);
-                        uint32_t param0 = vmst->core.regs[10]; // a0
+                    break;
-                        uint32_t mem_offset = param0 - MINIRV32_RAM_IMAGE_OFFSET;
+                    case UVM32_SYSCALL_STACKPROTECT: {
+                        // don't allow errant code to change it once set
+                        if (vmst->stack_canary == (uint8_t *)UVM32_NULL) {
+                            uint32_t param0 = vmst->core.regs[10]; // a0
+                            uint32_t mem_offset = param0 - MINIRV32_RAM_IMAGE_OFFSET;
+                            mem_offset &= ~0xF; // round up by 16 bytes
+                            mem_offset += 16*4;
 
-                        // check data fits in ram
+                            // check data fits in ram
-                        if (mem_offset > UVM32_MEMORY_SIZE) {
+                            if (mem_offset > UVM32_MEMORY_SIZE) {
-                            setStatusErr(vmst, UVM32_ERR_STACKOVERFLOW);
+                                setStatusErr(vmst, UVM32_ERR_INTERNAL_CORE);
-                            setup_err_evt(vmst, evt);
+                                setup_err_evt(vmst, evt);
+                            }
+                            // check canary is inside valid memory
+                            if (mem_offset < UVM32_MEMORY_SIZE) {
+                                // set canary
+                                vmst->stack_canary = &vmst->memory[mem_offset];
+                                *vmst->stack_canary = STACK_CANARY_VALUE;
+                            }
                         }
-                        // check canary is inside valid memory
+                    } break;
-                        if (mem_offset < UVM32_MEMORY_SIZE) {
+                    default:
-                            // set canary
+                        // user defined syscalls
-                            vmst->stack_canary = &vmst->memory[mem_offset];
+                        vmst->ioevt.typ = UVM32_EVT_SYSCALL;
-                            *vmst->stack_canary = STACK_CANARY_VALUE;
+                        vmst->ioevt.data.syscall.code = syscall;
-                        }
+                        vmst->ioevt.data.syscall.ret = &vmst->core.regs[12];        // a2
-                    }
+                        vmst->ioevt.data.syscall.params[0] = &vmst->core.regs[10];  // a0
-                } break;
+                        vmst->ioevt.data.syscall.params[1] = &vmst->core.regs[11];  // a1
-                default:
+                        setStatus(vmst, UVM32_STATUS_PAUSED);
-                    // user defined syscalls
+                    break;
-                    vmst->ioevt.typ = UVM32_EVT_SYSCALL;
+                }   // end switch(syscall)
-                    vmst->ioevt.data.syscall.code = syscall;
+            } break; // end ecall
-                    vmst->ioevt.data.syscall.ret = &vmst->core.regs[12];        // a2
+            default:
-                    vmst->ioevt.data.syscall.params[0] = &vmst->core.regs[10];  // a0
+                // unhandled exception
-                    vmst->ioevt.data.syscall.params[1] = &vmst->core.regs[11];  // a1
+                setStatusErr(vmst, UVM32_ERR_INTERNAL_CORE);
-                    setStatus(vmst, UVM32_STATUS_PAUSED);
+                setup_err_evt(vmst, evt);
-                break;
+            break;
-            }
-        } else if (ret != 0) {
-            // unhandled exception
-            setStatusErr(vmst, UVM32_ERR_INTERNAL_CORE);
-            setup_err_evt(vmst, evt);
         }
 
         num_instr++;
@@ -213,8 +221,10 @@ uint32_t uvm32_run(uvm32_state_t *vmst, uvm32_evt_t *evt, uint32_t instr_meter)
             setup_err_evt(vmst, evt);
             return num_instr;
         }
+
     }
 
+
     if (vmst->status == UVM32_STATUS_ENDED) {
         evt->typ = UVM32_EVT_END;
         return num_instr;

uvm32/uvm32.h

@@ -20,7 +20,6 @@
     X(UVM32_ERR_INTERNAL_CORE) \
     X(UVM32_ERR_INTERNAL_STATE) \
     X(UVM32_ERR_ARGS) \
-    X(UVM32_ERR_STACKOVERFLOW) \
 
 #define X(name) name,
 typedef enum {
@@ -55,7 +54,7 @@ typedef struct {
 
 #define MINIRV32_DECORATE static
 #define MINI_RV32_RAM_SIZE UVM32_MEMORY_SIZE
-#define MINIRV32_POSTEXEC(pc, ir, retval) {if (retval > 0) return 3;}
+#define MINIRV32_POSTEXEC(pc, ir, retval) {if (retval > 0) return retval;}
 #ifndef MINIRV32_IMPLEMENTATION
 #define MINIRV32_STEPPROTO
 #endif