Test metering, prove that system can resume after a hang error with a range of meter sizes

This commit is contained in:
Toby Jaffey 2025-12-10 22:30:19 +00:00
parent 9d9e7542fc
commit ac1975a820
14 changed files with 222 additions and 53 deletions

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@ -171,6 +171,7 @@ int main(int argc, char *argv[]) {
printf("UVM32_EVT_ERR '%s' (%d)\n", evt.data.err.errstr, (int)evt.data.err.errcode);
if (evt.data.err.errcode == UVM32_ERR_HUNG) {
printf("VM may have hung, increase max_instrs_per_run\n");
uvm32_clearError(&vmst); // allow to continue
} else {
isrunning = false;
}

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@ -1,4 +1,10 @@
TESTS = example_1 stackoverflow custom_syscall
TESTS = \
basic_syscalls \
stackoverflow \
custom_syscall \
syscall_args \
meter
RUNCMD = $(foreach TEST,${TESTS},make -C ${TEST} &&)
CLEANCMD = $(foreach TEST,${TESTS},make -C ${TEST} clean &&)

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@ -0,0 +1,10 @@
#include "uvm32_target.h"
void main(void) {
println("Hello world");
print("Hello world");
printdec(42);
printhex(0xDEADBEEF);
putc('G');
}

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@ -0,0 +1,56 @@
#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_syscalls(void) {
// check for println syscall
uvm32_run(&vmst, &evt, 1000);
TEST_ASSERT_EQUAL(evt.typ, UVM32_EVT_SYSCALL);
TEST_ASSERT_EQUAL(evt.data.syscall.code, UVM32_SYSCALL_PRINTLN);
TEST_ASSERT_EQUAL(0, strcmp(uvm32_getcstr(&vmst, &evt, ARG0), "Hello world"));
// check for print syscall
uvm32_run(&vmst, &evt, 1000);
TEST_ASSERT_EQUAL(evt.typ, UVM32_EVT_SYSCALL);
TEST_ASSERT_EQUAL(evt.data.syscall.code, UVM32_SYSCALL_PRINT);
TEST_ASSERT_EQUAL(0, strcmp(uvm32_getcstr(&vmst, &evt, ARG0), "Hello world"));
// check for printdec syscall
uvm32_run(&vmst, &evt, 1000);
TEST_ASSERT_EQUAL(evt.typ, UVM32_EVT_SYSCALL);
TEST_ASSERT_EQUAL(evt.data.syscall.code, UVM32_SYSCALL_PRINTDEC);
TEST_ASSERT_EQUAL(42, uvm32_getval(&vmst, &evt, ARG0));
// check for printhex syscall
uvm32_run(&vmst, &evt, 1000);
TEST_ASSERT_EQUAL(evt.typ, UVM32_EVT_SYSCALL);
TEST_ASSERT_EQUAL(evt.data.syscall.code, UVM32_SYSCALL_PRINTHEX);
TEST_ASSERT_EQUAL(0xDEADBEEF, uvm32_getval(&vmst, &evt, ARG0));
// check for putc syscall
uvm32_run(&vmst, &evt, 1000);
TEST_ASSERT_EQUAL(evt.typ, UVM32_EVT_SYSCALL);
TEST_ASSERT_EQUAL(evt.data.syscall.code, UVM32_SYSCALL_PUTC);
TEST_ASSERT_EQUAL('G', uvm32_getval(&vmst, &evt, ARG0));
// run vm to completion
uvm32_run(&vmst, &evt, 10000);
TEST_ASSERT_EQUAL(evt.typ, UVM32_EVT_END);
}

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@ -1,6 +0,0 @@
#include "uvm32_target.h"
void main(void) {
println("Hello world");
}

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@ -1,33 +0,0 @@
#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_helloworld1(void) {
// run the vm
uvm32_run(&vmst, &evt, 10000);
// check for println syscall
TEST_ASSERT_EQUAL(evt.typ, UVM32_EVT_SYSCALL);
TEST_ASSERT_EQUAL(evt.data.syscall.code, UVM32_SYSCALL_PRINTLN);
const char *str = uvm32_getcstr(&vmst, &evt, ARG0);
TEST_ASSERT_EQUAL(0, strcmp(str, "Hello world"));
// run vm to completion
uvm32_run(&vmst, &evt, 10000);
TEST_ASSERT_EQUAL(evt.typ, UVM32_EVT_END);
}

33
test/meter/Makefile Normal file
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@ -0,0 +1,33 @@
C_COMPILER=gcc
UNITY_ROOT=../unity
CFLAGS=-std=c99
CFLAGS += -Wall
CFLAGS += -Werror
CFLAGS += -DUVM32_MEMORY_SIZE=16384
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)

14
test/meter/rom/Makefile Normal file
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@ -0,0 +1,14 @@
TOPDIR=../../../
PROJECT:=$(shell basename ${PWD})
SRCS=${PROJECT}.c ${TOPDIR}/apps/crt0.S
OPT=-O0 # don't let optimiser remove stall loop
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

15
test/meter/rom/rom.c Normal file
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@ -0,0 +1,15 @@
#include "uvm32_target.h"
void stall(void) {
volatile uint32_t i;
for (i=0;i<100;i++) {
}
}
void main(void) {
for (int i=0;i<100;i++) {
stall();
printdec(i);
}
}

58
test/meter/test/tests.c Normal file
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@ -0,0 +1,58 @@
#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) {
}
// run program until printdec() reaches 100
// every time it hangs, resume
// run in batches of num_instr
void metered_run(uint32_t num_instr) {
uint32_t expected = 0;
while(expected < 100) {
uvm32_run(&vmst, &evt, num_instr);
switch(evt.typ) {
case UVM32_EVT_SYSCALL: {
TEST_ASSERT_EQUAL(UVM32_SYSCALL_PRINTDEC, evt.data.syscall.code);
uint32_t val = uvm32_getval(&vmst, &evt, ARG0);
TEST_ASSERT_EQUAL(val, expected);
expected++;
} break;
case UVM32_EVT_ERR:
TEST_ASSERT_EQUAL(evt.data.err.errcode, UVM32_ERR_HUNG);
uvm32_clearError(&vmst); // clear the hung error so it can continue
break;
case UVM32_EVT_END:
TEST_ASSERT_EQUAL(0, 1); // trigger an assert, we didn't get to 100000 yet
break;
}
}
// run vm to completion
uvm32_run(&vmst, &evt, 10000);
TEST_ASSERT_EQUAL(evt.typ, UVM32_EVT_END);
}
void test_meter(void) {
// test many different meter values, including 0 (which should run 1 instruction, as 0 is going to hang)
for (uint32_t i=0;i<1000;i++) {
uvm32_init(&vmst);
uvm32_load(&vmst, rom_bin, rom_bin_len);
metered_run(i);
}
}

View file

@ -138,27 +138,33 @@ void uvm32_clearError(uvm32_state_t *vmst) {
}
uint32_t uvm32_run(uvm32_state_t *vmst, uvm32_evt_t *evt, uint32_t instr_meter) {
uint32_t num_instr = 0;
const uint32_t min_instrs = 1;
uint32_t orig_instr_meter = instr_meter;
if (instr_meter < min_instrs) {
instr_meter = min_instrs;
}
if (vmst->stack_canary != UVM32_NULL && *vmst->stack_canary != STACK_CANARY_VALUE) {
setStatusErr(vmst, UVM32_ERR_INTERNAL_CORE);
setup_err_evt(vmst, evt);
return num_instr;
return orig_instr_meter - instr_meter;
}
if (vmst->status != UVM32_STATUS_PAUSED) {
setStatusErr(vmst, UVM32_ERR_NOTREADY);
setup_err_evt(vmst, evt);
return num_instr;
return orig_instr_meter - instr_meter;
}
setStatus(vmst, UVM32_STATUS_RUNNING);
// run CPU until no longer in running state
while(vmst->status == UVM32_STATUS_RUNNING) {
while(vmst->status == UVM32_STATUS_RUNNING && instr_meter > 0) {
uint64_t elapsedUs = 1;
uint32_t ret;
ret = MiniRV32IMAStep(vmst, &vmst->core, vmst->memory, 0, elapsedUs, 1);
instr_meter--;
switch(ret) {
case 0: // ok
@ -213,28 +219,25 @@ uint32_t uvm32_run(uvm32_state_t *vmst, uvm32_evt_t *evt, uint32_t instr_meter)
break;
}
num_instr++;
// check instruction meter, in case of hang/infinite loop
if (instr_meter-- == 0) {
if (vmst->status == UVM32_STATUS_RUNNING && instr_meter == 0) {
// no syscall occurred, so we've hung
setStatusErr(vmst, UVM32_ERR_HUNG);
setup_err_evt(vmst, evt);
return num_instr;
return orig_instr_meter - instr_meter;
}
}
if (vmst->status == UVM32_STATUS_ENDED) {
evt->typ = UVM32_EVT_END;
return num_instr;
return orig_instr_meter - instr_meter;
}
// an event is ready
if (vmst->status == UVM32_STATUS_PAUSED) {
// send back the built up event
UVM32_MEMCPY(evt, &vmst->ioevt, sizeof(uvm32_evt_t));
return num_instr;
return orig_instr_meter - instr_meter;
} else {
if (vmst->status == UVM32_STATUS_ERROR) {
setup_err_evt(vmst, evt);
@ -242,7 +245,7 @@ uint32_t uvm32_run(uvm32_state_t *vmst, uvm32_evt_t *evt, uint32_t instr_meter)
setStatusErr(vmst, UVM32_ERR_INTERNAL_STATE);
setup_err_evt(vmst, evt);
}
return num_instr;
return orig_instr_meter - instr_meter;
}
}
@ -301,3 +304,14 @@ uvm32_evt_syscall_buf_t uvm32_getbuf(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm3
return scb;
}
uvm32_evt_syscall_buf_t uvm32_getbuf_fixed(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm32_arg_t argPtr, uint32_t len) {
uvm32_evt_syscall_buf_t scb;
if (!get_safeptr(vmst, uvm32_getval(vmst, evt, argPtr), len, &scb)) {
setStatusErr(vmst, UVM32_ERR_MEM_RD);
garbage = 0;
scb.ptr = (uint8_t *)&garbage;
scb.len = 0;
}
return scb;
}

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@ -97,6 +97,7 @@ uint32_t uvm32_getval(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm32_arg_t);
const char *uvm32_getcstr(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm32_arg_t);
void uvm32_setval(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm32_arg_t, uint32_t val);
uvm32_evt_syscall_buf_t uvm32_getbuf(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm32_arg_t argPtr, uvm32_arg_t argLen);
uvm32_evt_syscall_buf_t uvm32_getbuf_fixed(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm32_arg_t argPtr, uint32_t len);
void uvm32_clearError(uvm32_state_t *vmst);