sys/targets: add OS/Arch name consts

We use strings to identify OS/Arch.
These strings are duplicated throughout the code base massively.
golangci-lint points to possiblity of typos and duplication.
We already had to define these names in pkg/csource
and disable checking for prog package. A future change triggers
such warnings in another package.

Add OS/Arch name consts to sys/targets so that they can be used
to refer to OS/Arch. Use the consts everywhere.

8 files changed, 107 insertions, 76 deletions

diff --git a/sys/fuchsia/fidlgen/main.go b/sys/fuchsia/fidlgen/main.go
index 8c48ac312..b4942a08d 100644
--- a/sys/fuchsia/fidlgen/main.go
+++ b/sys/fuchsia/fidlgen/main.go
@@ -19,7 +19,7 @@ import (
 
 func main() {
 	targetArch := os.Getenv("TARGETARCH")
-	target := targets.Get("fuchsia", targetArch)
+	target := targets.Get(targets.Fuchsia, targetArch)
 	if target == nil {
 		failf("unknown TARGETARCH %s", targetArch)
 	}
diff --git a/sys/linux/init.go b/sys/linux/init.go
index 928ba17e5..a18fa99c4 100644
--- a/sys/linux/init.go
+++ b/sys/linux/init.go
@@ -79,11 +79,11 @@ func InitTarget(target *prog.Target) {
 	}
 
 	switch target.Arch {
-	case "amd64":
+	case targets.AMD64:
 		target.SpecialPointers = []uint64{
 			0xffffffff81000000, // kernel text
 		}
-	case "386", "arm64", "arm", "ppc64le", "mips64le", "s390x", "riscv64":
+	case targets.I386, targets.ARM64, targets.ARM, targets.PPC64LE, targets.MIPS64LE, targets.S390x, targets.RiscV64:
 	default:
 		panic("unknown arch")
 	}
diff --git a/sys/linux/init_test.go b/sys/linux/init_test.go
index df0622ba3..201ce762b 100644
--- a/sys/linux/init_test.go
+++ b/sys/linux/init_test.go
@@ -8,10 +8,11 @@ import (
 
 	"github.com/google/syzkaller/prog"
 	_ "github.com/google/syzkaller/sys/linux/gen"
+	"github.com/google/syzkaller/sys/targets"
 )
 
 func TestNeutralize(t *testing.T) {
-	prog.TestDeserializeHelper(t, "linux", "amd64", nil, []prog.DeserializeTest{
+	prog.TestDeserializeHelper(t, targets.Linux, targets.AMD64, nil, []prog.DeserializeTest{
 		{
 			In:  `syslog(0x10000000006, 0x0, 0x0)`,
 			Out: `syslog(0x9, 0x0, 0x0)`,
diff --git a/sys/openbsd/init_test.go b/sys/openbsd/init_test.go
index 7f3d9a489..3a6c2c14c 100644
--- a/sys/openbsd/init_test.go
+++ b/sys/openbsd/init_test.go
@@ -8,10 +8,11 @@ import (
 
 	"github.com/google/syzkaller/prog"
 	_ "github.com/google/syzkaller/sys/openbsd/gen"
+	"github.com/google/syzkaller/sys/targets"
 )
 
 func TestNeutralize(t *testing.T) {
-	prog.TestDeserializeHelper(t, "openbsd", "amd64", nil, []prog.DeserializeTest{
+	prog.TestDeserializeHelper(t, targets.OpenBSD, targets.AMD64, nil, []prog.DeserializeTest{
 		{
 			In:  `chflagsat(0x0, 0x0, 0x60004, 0x0)`,
 			Out: `chflagsat(0x0, 0x0, 0x0, 0x0)`,
diff --git a/sys/syz-extract/extract.go b/sys/syz-extract/extract.go
index 10b8b6541..a1ddaa86c 100644
--- a/sys/syz-extract/extract.go
+++ b/sys/syz-extract/extract.go
@@ -57,15 +57,15 @@ type Extractor interface {
 }
 
 var extractors = map[string]Extractor{
-	"akaros":  new(akaros),
-	"linux":   new(linux),
-	"freebsd": new(freebsd),
-	"netbsd":  new(netbsd),
-	"openbsd": new(openbsd),
-	"android": new(linux),
-	"fuchsia": new(fuchsia),
-	"windows": new(windows),
-	"trusty":  new(trusty),
+	targets.Akaros:  new(akaros),
+	targets.Linux:   new(linux),
+	targets.FreeBSD: new(freebsd),
+	targets.NetBSD:  new(netbsd),
+	targets.OpenBSD: new(openbsd),
+	"android":       new(linux),
+	targets.Fuchsia: new(fuchsia),
+	targets.Windows: new(windows),
+	targets.Trusty:  new(trusty),
 }
 
 func main() {
@@ -243,7 +243,7 @@ func archFileList(os, arch string, files []string) (string, []string, []string,
 	android := false
 	if os == "android" {
 		android = true
-		os = "linux"
+		os = targets.Linux
 	}
 	var arches []string
 	if arch != "" {
@@ -253,7 +253,7 @@ func archFileList(os, arch string, files []string) (string, []string, []string,
 			arches = append(arches, arch)
 		}
 		if android {
-			arches = []string{"386", "amd64", "arm", "arm64"}
+			arches = []string{targets.I386, targets.AMD64, targets.ARM, targets.ARM64}
 		}
 		sort.Strings(arches)
 	}
@@ -278,7 +278,7 @@ func archFileList(os, arch string, files []string) (string, []string, []string,
 		}
 		for _, f := range matches {
 			f = filepath.Base(f)
-			if manualFiles[f] || os == "linux" && android != androidFiles[f] {
+			if manualFiles[f] || os == targets.Linux && android != androidFiles[f] {
 				continue
 			}
 			files = append(files, f)
diff --git a/sys/syz-extract/linux.go b/sys/syz-extract/linux.go
index 05789ef55..47e5d20e6 100644
--- a/sys/syz-extract/linux.go
+++ b/sys/syz-extract/linux.go
@@ -12,6 +12,7 @@ import (
 
 	"github.com/google/syzkaller/pkg/compiler"
 	"github.com/google/syzkaller/pkg/osutil"
+	"github.com/google/syzkaller/sys/targets"
 )
 
 type linux struct{}
@@ -134,7 +135,8 @@ func (*linux) prepareArch(arch *Arch) error {
 }
 
 func (*linux) processFile(arch *Arch, info *compiler.ConstInfo) (map[string]uint64, map[string]bool, error) {
-	if strings.HasSuffix(info.File, "_kvm.txt") && (arch.target.Arch == "arm" || arch.target.Arch == "riscv64") {
+	if strings.HasSuffix(info.File, "_kvm.txt") &&
+		(arch.target.Arch == targets.ARM || arch.target.Arch == targets.RiscV64) {
 		// Hack: KVM is not supported on ARM anymore. We may want some more official support
 		// for marking descriptions arch-specific, but so far this combination is the only
 		// one. For riscv64, KVM is not supported yet but might be in the future.
diff --git a/sys/syz-sysgen/sysgen.go b/sys/syz-sysgen/sysgen.go
index 8dfedb6a2..62f36c3d3 100644
--- a/sys/syz-sysgen/sysgen.go
+++ b/sys/syz-sysgen/sysgen.go
@@ -115,7 +115,7 @@ func main() {
 				}
 				consts := constFile.Arch(job.Target.Arch)
 				top := descriptions
-				if OS == "linux" && (job.Target.Arch == "arm" || job.Target.Arch == "riscv64") {
+				if OS == targets.Linux && (job.Target.Arch == targets.ARM || job.Target.Arch == targets.RiscV64) {
 					// Hack: KVM is not supported on ARM anymore. On riscv64 it
 					// is not supported yet but might be in the future.
 					// Note: syz-extract also ignores this file for arm and
@@ -125,7 +125,7 @@ func main() {
 						return !strings.HasSuffix(pos.File, "_kvm.txt")
 					})
 				}
-				if OS == "test" {
+				if OS == targets.TestOS {
 					constInfo := compiler.ExtractConsts(top, job.Target, eh)
 					compiler.FabricateSyscallConsts(job.Target, constInfo, consts)
 				}
diff --git a/sys/targets/targets.go b/sys/targets/targets.go
index 28ee5b376..ff218aa6c 100644
--- a/sys/targets/targets.go
+++ b/sys/targets/targets.go
@@ -78,6 +78,31 @@ type osCommon struct {
 	cflags []string
 }
 
+const (
+	Akaros  = "akaros"
+	FreeBSD = "freebsd"
+	Fuchsia = "fuchsia"
+	Linux   = "linux"
+	NetBSD  = "netbsd"
+	OpenBSD = "openbsd"
+	TestOS  = "test"
+	Trusty  = "trusty"
+	Windows = "windows"
+
+	AMD64               = "amd64"
+	ARM64               = "arm64"
+	ARM                 = "arm"
+	I386                = "386"
+	MIPS64LE            = "mips64le"
+	PPC64LE             = "ppc64le"
+	S390x               = "s390x"
+	RiscV64             = "riscv64"
+	TestArch64          = "64"
+	TestArch64Fork      = "64_fork"
+	TestArch32Shmem     = "32_shmem"
+	TestArch32ForkShmem = "32_fork_shmem"
+)
+
 func Get(OS, arch string) *Target {
 	return GetEx(OS, arch, useClang)
 }
@@ -103,8 +128,8 @@ func GetEx(OS, arch string, clang bool) *Target {
 
 // nolint: lll
 var List = map[string]map[string]*Target{
-	"test": {
-		"64": {
+	TestOS: {
+		TestArch64: {
 			PtrSize:  8,
 			PageSize: 4 << 10,
 			// Compile with -no-pie due to issues with ASan + ASLR on ppc64le.
@@ -116,7 +141,7 @@ var List = map[string]map[string]*Target{
 				ExecutorUsesForkServer: false,
 			},
 		},
-		"64_fork": {
+		TestArch64Fork: {
 			PtrSize:  8,
 			PageSize: 8 << 10,
 			// Compile with -no-pie due to issues with ASan + ASLR on ppc64le.
@@ -128,7 +153,7 @@ var List = map[string]map[string]*Target{
 				ExecutorUsesForkServer: true,
 			},
 		},
-		"32_shmem": {
+		TestArch32Shmem: {
 			PtrSize:        4,
 			PageSize:       8 << 10,
 			Int64Alignment: 4,
@@ -141,7 +166,7 @@ var List = map[string]map[string]*Target{
 				ExecutorUsesForkServer: false,
 			},
 		},
-		"32_fork_shmem": {
+		TestArch32ForkShmem: {
 			PtrSize:  4,
 			PageSize: 4 << 10,
 			CFlags:   []string{"-m32", "-static"},
@@ -155,8 +180,8 @@ var List = map[string]map[string]*Target{
 			},
 		},
 	},
-	"linux": {
-		"amd64": {
+	Linux: {
+		AMD64: {
 			PtrSize:          8,
 			PageSize:         4 << 10,
 			LittleEndian:     true,
@@ -170,8 +195,8 @@ var List = map[string]map[string]*Target{
 				return nr >= 313
 			},
 		},
-		"386": {
-			VMArch:           "amd64",
+		I386: {
+			VMArch:           AMD64,
 			PtrSize:          4,
 			PageSize:         4 << 10,
 			Int64Alignment:   4,
@@ -181,7 +206,7 @@ var List = map[string]map[string]*Target{
 			KernelArch:       "i386",
 			KernelHeaderArch: "x86",
 		},
-		"arm64": {
+		ARM64: {
 			PtrSize:          8,
 			PageSize:         4 << 10,
 			LittleEndian:     true,
@@ -189,8 +214,8 @@ var List = map[string]map[string]*Target{
 			KernelArch:       "arm64",
 			KernelHeaderArch: "arm64",
 		},
-		"arm": {
-			VMArch:           "arm64",
+		ARM: {
+			VMArch:           ARM64,
 			PtrSize:          4,
 			PageSize:         4 << 10,
 			LittleEndian:     true,
@@ -199,8 +224,7 @@ var List = map[string]map[string]*Target{
 			KernelArch:       "arm",
 			KernelHeaderArch: "arm",
 		},
-		"mips64le": {
-			VMArch:           "mips64le",
+		MIPS64LE: {
 			PtrSize:          8,
 			PageSize:         4 << 10,
 			LittleEndian:     true,
@@ -209,7 +233,7 @@ var List = map[string]map[string]*Target{
 			KernelArch:       "mips",
 			KernelHeaderArch: "mips",
 		},
-		"ppc64le": {
+		PPC64LE: {
 			PtrSize:          8,
 			PageSize:         64 << 10,
 			LittleEndian:     true,
@@ -218,7 +242,7 @@ var List = map[string]map[string]*Target{
 			KernelArch:       "powerpc",
 			KernelHeaderArch: "powerpc",
 		},
-		"s390x": {
+		S390x: {
 			PtrSize:          8,
 			PageSize:         4 << 10,
 			DataOffset:       0xfffff000,
@@ -234,7 +258,7 @@ var List = map[string]map[string]*Target{
 				"mmap": "mmap",
 			},
 		},
-		"riscv64": {
+		RiscV64: {
 			PtrSize:          8,
 			PageSize:         4 << 10,
 			LittleEndian:     true,
@@ -243,8 +267,8 @@ var List = map[string]map[string]*Target{
 			KernelHeaderArch: "riscv",
 		},
 	},
-	"freebsd": {
-		"amd64": {
+	FreeBSD: {
+		AMD64: {
 			PtrSize:           8,
 			PageSize:          4 << 10,
 			LittleEndian:      true,
@@ -252,8 +276,8 @@ var List = map[string]map[string]*Target{
 			CFlags:            []string{"-m64"},
 			NeedSyscallDefine: dontNeedSyscallDefine,
 		},
-		"386": {
-			VMArch:   "amd64",
+		I386: {
+			VMArch:   AMD64,
 			PtrSize:  4,
 			PageSize: 4 << 10,
 			// The default DataOffset doesn't work with 32-bit
@@ -266,8 +290,8 @@ var List = map[string]map[string]*Target{
 			NeedSyscallDefine: dontNeedSyscallDefine,
 		},
 	},
-	"netbsd": {
-		"amd64": {
+	NetBSD: {
+		AMD64: {
 			PtrSize:      8,
 			PageSize:     4 << 10,
 			LittleEndian: true,
@@ -279,8 +303,8 @@ var List = map[string]map[string]*Target{
 			CCompiler: sourceDirVar + "/tools/bin/x86_64--netbsd-g++",
 		},
 	},
-	"openbsd": {
-		"amd64": {
+	OpenBSD: {
+		AMD64: {
 			PtrSize:      8,
 			PageSize:     4 << 10,
 			LittleEndian: true,
@@ -313,8 +337,8 @@ var List = map[string]map[string]*Target{
 			},
 		},
 	},
-	"fuchsia": {
-		"amd64": {
+	Fuchsia: {
+		AMD64: {
 			PtrSize:          8,
 			PageSize:         4 << 10,
 			LittleEndian:     true,
@@ -323,26 +347,26 @@ var List = map[string]map[string]*Target{
 			Objdump:          sourceDirVar + "/prebuilt/third_party/clang/linux-x64/bin/llvm-objdump",
 			CFlags:           fuchsiaCFlags("x64", "x86_64"),
 		},
-		"arm64": {
+		ARM64: {
 			PtrSize:          8,
 			PageSize:         4 << 10,
 			LittleEndian:     true,
-			KernelHeaderArch: "arm64",
+			KernelHeaderArch: ARM64,
 			CCompiler:        sourceDirVar + "/prebuilt/third_party/clang/linux-x64/bin/clang",
 			Objdump:          sourceDirVar + "/prebuilt/third_party/clang/linux-x64/bin/llvm-objdump",
-			CFlags:           fuchsiaCFlags("arm64", "aarch64"),
+			CFlags:           fuchsiaCFlags(ARM64, "aarch64"),
 		},
 	},
-	"windows": {
-		"amd64": {
+	Windows: {
+		AMD64: {
 			PtrSize: 8,
 			// TODO(dvyukov): what should we do about 4k vs 64k?
 			PageSize:     4 << 10,
 			LittleEndian: true,
 		},
 	},
-	"akaros": {
-		"amd64": {
+	Akaros: {
+		AMD64: {
 			PtrSize:           8,
 			PageSize:          4 << 10,
 			LittleEndian:      true,
@@ -354,8 +378,8 @@ var List = map[string]map[string]*Target{
 			},
 		},
 	},
-	"trusty": {
-		"arm": {
+	Trusty: {
+		ARM: {
 			PtrSize:           4,
 			PageSize:          4 << 10,
 			LittleEndian:      true,
@@ -365,7 +389,7 @@ var List = map[string]map[string]*Target{
 }
 
 var oses = map[string]osCommon{
-	"linux": {
+	Linux: {
 		SyscallNumbers:         true,
 		SyscallPrefix:          "__NR_",
 		ExecutorUsesShmem:      true,
@@ -373,7 +397,7 @@ var oses = map[string]osCommon{
 		KernelObject:           "vmlinux",
 		cflags:                 []string{"-static"},
 	},
-	"freebsd": {
+	FreeBSD: {
 		SyscallNumbers:         true,
 		Int64SyscallArgs:       true,
 		SyscallPrefix:          "SYS_",
@@ -383,15 +407,15 @@ var oses = map[string]osCommon{
 		CPP:                    "g++",
 		cflags:                 []string{"-static", "-lc++"},
 	},
-	"netbsd": {
-		BuildOS:                "linux",
+	NetBSD: {
+		BuildOS:                Linux,
 		SyscallNumbers:         true,
 		SyscallPrefix:          "SYS_",
 		ExecutorUsesShmem:      true,
 		ExecutorUsesForkServer: true,
 		KernelObject:           "netbsd.gdb",
 	},
-	"openbsd": {
+	OpenBSD: {
 		SyscallNumbers:         true,
 		SyscallPrefix:          "SYS_",
 		ExecutorUsesShmem:      true,
@@ -399,8 +423,8 @@ var oses = map[string]osCommon{
 		KernelObject:           "bsd.gdb",
 		CPP:                    "ecpp",
 	},
-	"fuchsia": {
-		BuildOS:                "linux",
+	Fuchsia: {
+		BuildOS:                Linux,
 		SyscallNumbers:         false,
 		ExecutorUsesShmem:      false,
 		ExecutorUsesForkServer: false,
@@ -408,15 +432,15 @@ var oses = map[string]osCommon{
 		SyzExecutorCmd:         "syz-executor",
 		KernelObject:           "zircon.elf",
 	},
-	"windows": {
+	Windows: {
 		SyscallNumbers:         false,
 		ExecutorUsesShmem:      false,
 		ExecutorUsesForkServer: false,
 		ExeExtension:           ".exe",
 		KernelObject:           "vmlinux",
 	},
-	"akaros": {
-		BuildOS:                "linux",
+	Akaros: {
+		BuildOS:                Linux,
 		SyscallNumbers:         true,
 		SyscallPrefix:          "SYS_",
 		ExecutorUsesShmem:      false,
@@ -424,7 +448,7 @@ var oses = map[string]osCommon{
 		HostFuzzer:             true,
 		KernelObject:           "akaros-kernel-64b",
 	},
-	"trusty": {
+	Trusty: {
 		SyscallNumbers:   true,
 		Int64SyscallArgs: true,
 		SyscallPrefix:    "__NR_",
@@ -479,14 +503,14 @@ func init() {
 	goarch := runtime.GOARCH
 	goos := runtime.GOOS
 	if goos == "android" {
-		goos = "linux"
+		goos = Linux
 	}
-	for _, target := range List["test"] {
+	for _, target := range List[TestOS] {
 		if List[goos] != nil {
 			if host := List[goos][goarch]; host != nil {
 				target.CCompiler = host.CCompiler
 				target.CPP = host.CPP
-				if goos == "freebsd" {
+				if goos == FreeBSD {
 					// For some configurations -no-pie is passed to the compiler,
 					// which is not used by clang.
 					// Ensure clang does not complain about it.
@@ -498,18 +522,18 @@ func init() {
 				// In ESA/390 mode, the CPU is able to address only 31bit of memory but
 				// arithmetic operations are still 32bit
 				// Fix cflags by replacing compiler's -m32 option with -m31
-				if goarch == "s390x" {
+				if goarch == S390x {
 					for i := range target.CFlags {
 						target.CFlags[i] = strings.Replace(target.CFlags[i], "-m32", "-m31", -1)
 					}
 				}
 			}
-			if target.PtrSize == 4 && goos == "freebsd" && goarch == "amd64" {
+			if target.PtrSize == 4 && goos == FreeBSD && goarch == AMD64 {
 				// A hack to let 32-bit "test" target tests run on FreeBSD:
 				// freebsd/386 requires a non-default DataOffset to avoid
 				// clobbering mappings created by the C runtime. Since that is the
 				// only target with this constraint, just special-case it for now.
-				target.DataOffset = List[goos]["386"].DataOffset
+				target.DataOffset = List[goos][I386].DataOffset
 			}
 		}
 		target.BuildOS = goos
@@ -524,6 +548,9 @@ func initTarget(target *Target, OS, arch string) {
 	target.initOther = new(sync.Once)
 	target.OS = OS
 	target.Arch = arch
+	if target.KernelArch == "" {
+		target.KernelArch = target.Arch
+	}
 	if target.NeedSyscallDefine == nil {
 		target.NeedSyscallDefine = needSyscallDefine
 	}
@@ -543,7 +570,7 @@ func initTarget(target *Target, OS, arch string) {
 	for i := range target.CFlags {
 		target.replaceSourceDir(&target.CFlags[i], sourceDir)
 	}
-	if OS == "linux" && arch == runtime.GOARCH {
+	if OS == Linux && arch == runtime.GOARCH {
 		// Don't use cross-compiler for native compilation, there are cases when this does not work:
 		// https://github.com/google/syzkaller/pull/619
 		// https://github.com/google/syzkaller/issues/387
@@ -573,8 +600,8 @@ func initTarget(target *Target, OS, arch string) {
 	for _, flags := range [][]string{commonCFlags, target.osCommon.cflags} {
 		target.CFlags = append(target.CFlags, flags...)
 	}
-	if OS == "test" {
-		if runtime.GOARCH != "s390x" {
+	if OS == TestOS {
+		if runtime.GOARCH != S390x {
 			target.LittleEndian = true
 		} else {
 			target.LittleEndian = false