cannon: load-elf command

.gitignore

@@ -7,3 +7,4 @@ venv
 *.log
 example/bin
 contracts/out
+state.json

cmd/load_elf.go

 package cmd
 
-import "github.com/urfave/cli/v2"
+import (
+	"debug/elf"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/urfave/cli/v2"
+
+	"cannon/mipsevm"
+)
+
+var (
+	LoadELFPathFlag = &cli.PathFlag{
+		Name:      "path",
+		Usage:     "Path to 32-bit big-endian MIPS ELF file",
+		TakesFile: true,
+		Required:  true,
+	}
+	LoadELFPatchFlag = &cli.StringSliceFlag{
+		Name:     "patch",
+		Usage:    "Type of patching to do",
+		Value:    cli.NewStringSlice("go", "stack"),
+		Required: false,
+	}
+	LoadELFOutFlag = &cli.PathFlag{
+		Name:     "out",
+		Usage:    "Output path to write JSON state to. State is dumped to stdout if set to empty string.",
+		Value:    "state.json",
+		Required: false,
+	}
+)
 
 func LoadELF(ctx *cli.Context) error {
-	// TODO
+	elfPath := ctx.Path(LoadELFPathFlag.Name)
+	elfProgram, err := elf.Open(elfPath)
+	if err != nil {
+		return fmt.Errorf("failed to open ELF file %q: %w", elfPath, err)
+	}
+	state, err := mipsevm.LoadELF(elfProgram)
+	if err != nil {
+		return fmt.Errorf("failed to load ELF data into VM state: %w", err)
+	}
+	for _, typ := range ctx.StringSlice(LoadELFPatchFlag.Name) {
+		switch typ {
+		case "stack":
+			err = mipsevm.PatchStack(state)
+		case "go":
+			err = mipsevm.PatchGo(elfProgram, state)
+		default:
+			return fmt.Errorf("unrecognized form of patching: %q", typ)
+		}
+		if err != nil {
+			return fmt.Errorf("failed to apply patch %s: %w", typ, err)
+		}
+	}
+	p := ctx.Path(LoadELFOutFlag.Name)
+	var out io.Writer
+	if p != "" {
+		f, err := os.OpenFile(p, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0755)
+		if err != nil {
+			return fmt.Errorf("failed to open output file: %w", err)
+		}
+		defer f.Close()
+		out = f
+	} else {
+		out = os.Stdout
+	}
+	enc := json.NewEncoder(out)
+	if err := enc.Encode(state); err != nil {
+		return fmt.Errorf("failed to encode state to JSON: %w", err)
+	}
 	return nil
 }
 
 var LoadELFCommand = &cli.Command{
 	Name:        "load-elf",
-	Usage:       "",
-	Description: "",
+	Usage:       "Load ELF file into Cannon JSON state",
+	Description: "Load ELF file into Cannon JSON state, optionally patch out functions",
 	Action:      LoadELF,
-	Flags:       nil,
+	Flags: []cli.Flag{
+		LoadELFPathFlag,
+		LoadELFPatchFlag,
+		LoadELFOutFlag,
+	},
 }

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/ethereum/go-ethereum v1.11.5
 	github.com/stretchr/testify v1.8.2
 	github.com/unicorn-engine/unicorn v0.0.0-20230207094436-7b8c63dfe650
+	github.com/urfave/cli/v2 v2.25.3
 )
 
 require (
@@ -20,6 +21,7 @@ require (
 	github.com/cockroachdb/logtags v0.0.0-20230118201751-21c54148d20b // indirect
 	github.com/cockroachdb/pebble v0.0.0-20230209160836-829675f94811 // indirect
 	github.com/cockroachdb/redact v1.1.3 // indirect
+	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/deckarep/golang-set/v2 v2.1.0 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
@@ -47,10 +49,12 @@ require (
 	github.com/prometheus/common v0.39.0 // indirect
 	github.com/prometheus/procfs v0.9.0 // indirect
 	github.com/rogpeppe/go-internal v1.9.0 // indirect
+	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/shirou/gopsutil v3.21.4-0.20210419000835-c7a38de76ee5+incompatible // indirect
 	github.com/syndtr/goleveldb v1.0.1-0.20210819022825-2ae1ddf74ef7 // indirect
 	github.com/tklauser/go-sysconf v0.3.5 // indirect
 	github.com/tklauser/numcpus v0.2.2 // indirect
+	github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 // indirect
 	golang.org/x/crypto v0.8.0 // indirect
 	golang.org/x/exp v0.0.0-20230206171751-46f607a40771 // indirect
 	golang.org/x/sys v0.7.0 // indirect

go.sum

@@ -43,6 +43,8 @@ github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc
 github.com/coreos/go-etcd v2.0.0+incompatible/go.mod h1:Jez6KQU2B/sWsbdaef3ED8NzMklzPG4d5KIOhIy30Tk=
 github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwcJI5acqYI6dE=
+github.com/cpuguy83/go-md2man/v2 v2.0.2 h1:p1EgwI/C7NhT0JmVkwCD2ZBK8j4aeHQX2pMHHBfMQ6w=
+github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
@@ -235,6 +237,8 @@ github.com/rogpeppe/go-internal v1.8.1/go.mod h1:JeRgkft04UBgHMgCIwADu4Pn6Mtm5d4
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
+github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/ryanuber/columnize v2.1.0+incompatible/go.mod h1:sm1tb6uqfes/u+d4ooFouqFdy9/2g9QGwK3SQygK0Ts=
 github.com/schollz/closestmatch v2.1.0+incompatible/go.mod h1:RtP1ddjLong6gTkbtmuhtR2uUrrJOpYzYRvbcPAid+g=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
@@ -271,6 +275,10 @@ github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGr
 github.com/ugorji/go v1.1.7/go.mod h1:kZn38zHttfInRq0xu/PH0az30d+z6vm202qpg1oXVMw=
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/ugorji/go/codec v1.1.7/go.mod h1:Ax+UKWsSmolVDwsd+7N3ZtXu+yMGCf907BLYF3GoBXY=
+github.com/urfave/cli/v2 v2.17.2-0.20221006022127-8f469abc00aa h1:5SqCsI/2Qya2bCzK15ozrqo2sZxkh0FHynJZOTVoV6Q=
+github.com/urfave/cli/v2 v2.17.2-0.20221006022127-8f469abc00aa/go.mod h1:1CNUng3PtjQMtRzJO4FMXBQvkGtuYRxxiR9xMa7jMwI=
+github.com/urfave/cli/v2 v2.25.3 h1:VJkt6wvEBOoSjPFQvOkv6iWIrsJyCrKGtCtxXWwmGeY=
+github.com/urfave/cli/v2 v2.25.3/go.mod h1:GHupkWPMM0M/sj1a2b4wUrWBPzazNrIjouW6fmdJLxc=
 github.com/urfave/negroni v1.0.0/go.mod h1:Meg73S6kFm/4PpbYdq35yYWoCZ9mS/YSx+lKnmiohz4=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
 github.com/valyala/fasthttp v1.6.0/go.mod h1:FstJa9V+Pj9vQ7OJie2qMHdwemEDaDiSdBnvPM1Su9w=
@@ -281,6 +289,8 @@ github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f/go.mod h1:N2
 github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415/go.mod h1:GwrjFmJcFw6At/Gs6z4yjiIwzuJ1/+UwLxMQDVQXShQ=
 github.com/xeipuuv/gojsonschema v1.2.0/go.mod h1:anYRn/JVcOK2ZgGU+IjEV4nwlhoK5sQluxsYJ78Id3Y=
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
+github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 h1:bAn7/zixMGCfxrRTfdpNzjtPYqr8smhKouy9mxVdGPU=
+github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673/go.mod h1:N3UwUGtsrSj3ccvlPHLoLsHnpR27oXr4ZE984MbSER8=
 github.com/yalp/jsonpath v0.0.0-20180802001716-5cc68e5049a0/go.mod h1:/LWChgwKmvncFJFHJ7Gvn9wZArjbV5/FppcK2fKk/tI=
 github.com/yudai/gojsondiff v1.0.0/go.mod h1:AY32+k2cwILAkW1fbgxQ5mUmMiZFgLIV+FBNExI05xg=
 github.com/yudai/golcs v0.0.0-20170316035057-ecda9a501e82/go.mod h1:lgjkn3NuSvDfVJdfcVVdX+jpBxNmX4rDAzaS45IcYoM=

main.go

 package main
 
 import (
+	"fmt"
+	"os"
+
 	"github.com/urfave/cli/v2"
 
 	"cannon/cmd"
@@ -16,4 +19,9 @@ func main() {
 		cmd.RunStepsCommand,
 		cmd.GenProofCommand,
 	}
+	err := app.Run(os.Args)
+	if err != nil {
+		_, _ = fmt.Fprintf(os.Stderr, "error: %v", err)
+		os.Exit(1)
+	}
 }

mipsevm/README.md

@@ -15,7 +15,7 @@ Supported 55 instructions:
 
 To run:
 1. Load a program into a state, e.g. using `LoadELF`.
-2. Patch the program if necessary: e.g. using `PatchVM` for Go programs.
+2. Patch the program if necessary: e.g. using `PatchGo` for Go programs, `PatchStack` for empty initial stack, etc.
 3. Load the state into a MIPS-32 configured unicorn instance, using `NewUnicorn`, `LoadUnicorn`
 4. Implement the `PreimageOracle` interface
 5. Instrument the emulator with the state, and pre-image oracle, using `NewUnicornState`

mipsevm/evm_test.go

@@ -128,8 +128,9 @@ func TestHelloEVM(t *testing.T) {
 	state, err := LoadELF(elfProgram)
 	require.NoError(t, err, "load ELF into state")
 
-	err = PatchVM(elfProgram, state)
+	err = PatchGo(elfProgram, state)
 	require.NoError(t, err, "apply Go runtime patches")
+	require.NoError(t, PatchStack(state), "add initial stack")
 
 	mu, err := NewUnicorn()
 	require.NoError(t, err, "load unicorn")
@@ -199,8 +200,9 @@ func TestClaimEVM(t *testing.T) {
 	state, err := LoadELF(elfProgram)
 	require.NoError(t, err, "load ELF into state")
 
-	err = PatchVM(elfProgram, state)
+	err = PatchGo(elfProgram, state)
 	require.NoError(t, err, "apply Go runtime patches")
+	require.NoError(t, PatchStack(state), "add initial stack")
 
 	mu, err := NewUnicorn()
 	require.NoError(t, err, "load unicorn")

mipsevm/patch.go

@@ -51,7 +51,7 @@ func LoadELF(f *elf.File) (*State, error) {
 	return s, nil
 }
 
-func PatchVM(f *elf.File, st *State) error {
+func PatchGo(f *elf.File, st *State) error {
 	symbols, err := f.Symbols()
 	if err != nil {
 		return fmt.Errorf("failed to read symbols data, cannot patch program: %w", err)
@@ -82,7 +82,10 @@ func PatchVM(f *elf.File, st *State) error {
 			}
 		}
 	}
+	return nil
+}
 
+func PatchStack(st *State) error {
 	// setup stack pointer
 	sp := uint32(0x7f_ff_d0_00)
 	// allocate 1 page for the initial stack data, and 16KB = 4 pages for the stack to grow

mipsevm/state_test.go

@@ -92,8 +92,9 @@ func TestHello(t *testing.T) {
 	state, err := LoadELF(elfProgram)
 	require.NoError(t, err, "load ELF into state")
 
-	err = PatchVM(elfProgram, state)
+	err = PatchGo(elfProgram, state)
 	require.NoError(t, err, "apply Go runtime patches")
+	require.NoError(t, PatchStack(state), "add initial stack")
 
 	mu, err := NewUnicorn()
 	require.NoError(t, err, "load unicorn")
@@ -194,8 +195,9 @@ func TestClaim(t *testing.T) {
 	state, err := LoadELF(elfProgram)
 	require.NoError(t, err, "load ELF into state")
 
-	err = PatchVM(elfProgram, state)
+	err = PatchGo(elfProgram, state)
 	require.NoError(t, err, "apply Go runtime patches")
+	require.NoError(t, PatchStack(state), "add initial stack")
 
 	mu, err := NewUnicorn()
 	require.NoError(t, err, "load unicorn")