tools/syz-declextract: export info about file ops interfaces

4 files changed, 130 insertions, 18 deletions

diff --git a/pkg/declextract/declextract.go b/pkg/declextract/declextract.go
index 0bf63f2e6..7320279bc 100644
--- a/pkg/declextract/declextract.go
+++ b/pkg/declextract/declextract.go
@@ -213,7 +213,7 @@ func (ctx *context) emitSyscall(syscalls *[]*Syscall, call *Syscall,
 			IdentifyingConst: identifyingConst,
 			Files:            []string{call.SourceFile},
 			Func:             call.Func,
-			AutoDescriptions: true,
+			AutoDescriptions: TristateYes,
 			scopeArg:         scopeArg,
 			scopeVal:         scopeVal,
 		})
@@ -232,6 +232,7 @@ func (ctx *context) processIouring() {
 			Files:            []string{op.SourceFile},
 			Func:             op.Func,
 			Access:           AccessUser,
+			AutoDescriptions: TristateNo,
 		})
 	}
 }
diff --git a/pkg/declextract/fileops.go b/pkg/declextract/fileops.go
index 408ccc4fc..47a01ce53 100644
--- a/pkg/declextract/fileops.go
+++ b/pkg/declextract/fileops.go
@@ -9,7 +9,10 @@ import (
 	"strings"
 )
 
-// TODO: also emit interface entry for file_operations.
+const (
+	ioctlCmdArg = 1
+	ioctlArgArg = 2
+)
 
 func (ctx *context) serializeFileOps() {
 	for _, ioctl := range ctx.Ioctls {
@@ -18,14 +21,60 @@ func (ctx *context) serializeFileOps() {
 	fopsToFiles := ctx.mapFopsToFiles()
 	for _, fops := range ctx.FileOps {
 		files := fopsToFiles[fops]
+		canGenerate := Tristate(len(files) != 0)
+		for _, op := range []string{fops.Read, fops.Write, fops.Mmap} {
+			if op == "" {
+				continue
+			}
+			file := ctx.funcDefinitionFile(op, fops.SourceFile)
+			if file == "" {
+				// TODO: in some cases we misparse fops defined via macros, e.g. for:
+				//	.write = (foo) ? bar : baz,
+				// We extract "foo".
+				continue
+			}
+			ctx.noteInterface(&Interface{
+				Type:             IfaceFileop,
+				Name:             op,
+				Func:             op,
+				Files:            []string{file},
+				AutoDescriptions: canGenerate,
+			})
+		}
+		var ioctlCmds []string
+		if fops.Ioctl != "" {
+			ioctlCmds = ctx.inferCommandVariants(fops.Ioctl, fops.SourceFile, ioctlCmdArg)
+			file := ctx.funcDefinitionFile(fops.Ioctl, fops.SourceFile)
+			for _, cmd := range ioctlCmds {
+				ctx.noteInterface(&Interface{
+					Type:             IfaceIoctl,
+					Name:             cmd,
+					IdentifyingConst: cmd,
+					Files:            []string{file},
+					Func:             fops.Ioctl,
+					AutoDescriptions: canGenerate,
+					scopeArg:         ioctlCmdArg,
+					scopeVal:         cmd,
+				})
+			}
+			if len(ioctlCmds) == 0 {
+				ctx.noteInterface(&Interface{
+					Type:             IfaceIoctl,
+					Name:             fops.Ioctl,
+					Files:            []string{file},
+					Func:             fops.Ioctl,
+					AutoDescriptions: canGenerate,
+				})
+			}
+		}
 		if len(files) == 0 {
 			continue // each unmapped entry means some code we don't know how to cover yet
 		}
-		ctx.createFops(fops, files)
+		ctx.createFops(fops, files, ioctlCmds)
 	}
 }
 
-func (ctx *context) createFops(fops *FileOps, files []string) {
+func (ctx *context) createFops(fops *FileOps, files, ioctlCmds []string) {
 	// If it has only open, then emit only openat that returns generic fd.
 	fdt := "fd"
 	if len(fops.ops()) > 1 || fops.Open == "" {
@@ -55,21 +104,17 @@ func (ctx *context) createFops(fops *FileOps, files []string) {
 			" flags flags[mmap_flags], fd %v, offset fileoff)\n", suffix, fdt)
 	}
 	if fops.Ioctl != "" {
-		ctx.createIoctls(fops, suffix, fdt)
+		ctx.createIoctls(fops, ioctlCmds, suffix, fdt)
 	}
 	ctx.fmt("\n")
 }
 
-func (ctx *context) createIoctls(fops *FileOps, suffix, fdt string) {
-	const (
-		cmdArg         = 1
-		argArg         = 2
-		defaultArgType = "ptr[in, array[int8]]"
-	)
-	cmds := ctx.inferCommandVariants(fops.Ioctl, fops.SourceFile, cmdArg)
+func (ctx *context) createIoctls(fops *FileOps, ioctlCmds []string, suffix, fdt string) {
+	const defaultArgType = "ptr[in, array[int8]]"
+	cmds := ctx.inferCommandVariants(fops.Ioctl, fops.SourceFile, ioctlCmdArg)
 	if len(cmds) == 0 {
 		retType := ctx.inferReturnType(fops.Ioctl, fops.SourceFile, -1, "")
-		argType := ctx.inferArgType(fops.Ioctl, fops.SourceFile, argArg, -1, "")
+		argType := ctx.inferArgType(fops.Ioctl, fops.SourceFile, ioctlArgArg, -1, "")
 		if argType == "" {
 			argType = defaultArgType
 		}
@@ -85,12 +130,12 @@ func (ctx *context) createIoctls(fops *FileOps, suffix, fdt string) {
 			}
 			argType = ctx.fieldType(f, nil, "", false)
 		} else {
-			argType = ctx.inferArgType(fops.Ioctl, fops.SourceFile, argArg, cmdArg, cmd)
+			argType = ctx.inferArgType(fops.Ioctl, fops.SourceFile, ioctlArgArg, ioctlCmdArg, cmd)
 			if argType == "" {
 				argType = defaultArgType
 			}
 		}
-		retType := ctx.inferReturnType(fops.Ioctl, fops.SourceFile, cmdArg, cmd)
+		retType := ctx.inferReturnType(fops.Ioctl, fops.SourceFile, ioctlCmdArg, cmd)
 		name := ctx.uniqualize("ioctl cmd", cmd)
 		ctx.fmt("ioctl%v_%v(fd %v, cmd const[%v], arg %v) %v\n",
 			autoSuffix, name, fdt, cmd, argType, retType)
diff --git a/pkg/declextract/interface.go b/pkg/declextract/interface.go
index dd5bfa1d4..e8ace450b 100644
--- a/pkg/declextract/interface.go
+++ b/pkg/declextract/interface.go
@@ -18,8 +18,8 @@ type Interface struct {
 	Func               string
 	Access             string
 	Subsystems         []string
-	ManualDescriptions bool
-	AutoDescriptions   bool
+	ManualDescriptions TristateVal
+	AutoDescriptions   TristateVal
 	ReachableLOC       int
 	CoveredBlocks      int
 	TotalBlocks        int
@@ -28,9 +28,19 @@ type Interface struct {
 	scopeVal string
 }
 
+type TristateVal int
+
+const (
+	TristateUnknown TristateVal = iota
+	TristateYes
+	TristateNo
+)
+
 const (
 	IfaceSyscall   = "SYSCALL"
 	IfaceNetlinkOp = "NETLINK"
+	IfaceFileop    = "FILEOP"
+	IfaceIoctl     = "IOCTL"
 	IfaceIouring   = "IOURING"
 
 	AccessUnknown = "unknown"
@@ -44,6 +54,17 @@ func (ctx *context) noteInterface(iface *Interface) {
 }
 
 func (ctx *context) finishInterfaces() {
+	ctx.interfaces = sortAndDedupSlice(ctx.interfaces)
+	count := make(map[string]int)
+	for _, iface := range ctx.interfaces {
+		count[iface.Type+iface.Name]++
+	}
+	// Lots of file ops have the same name, add file name to them.
+	for _, iface := range ctx.interfaces {
+		if count[iface.Type+iface.Name] > 1 {
+			iface.Name = iface.Name + "_" + fileNameSuffix(iface.Files[0])
+		}
+	}
 	for _, iface := range ctx.interfaces {
 		ctx.calculateLOC(iface)
 		slices.Sort(iface.Files)
@@ -51,6 +72,9 @@ func (ctx *context) finishInterfaces() {
 		if iface.Access == "" {
 			iface.Access = AccessUnknown
 		}
+		if iface.Access == "" {
+			iface.Access = AccessUnknown
+		}
 	}
 	ctx.interfaces = sortAndDedupSlice(ctx.interfaces)
 }
@@ -148,3 +172,45 @@ func (ctx *context) findFunc(name, file string) *Function {
 	}
 	return ctx.funcs[name]
 }
+
+func (ctx *context) funcDefinitionFile(name, calledFrom string) string {
+	fn := ctx.findFunc(name, calledFrom)
+	if fn == nil {
+		return ""
+	}
+	return fn.File
+}
+
+func fileNameSuffix(file string) string {
+	// Remove file extension.
+	ext := strings.LastIndexByte(file, '.')
+	if ext != -1 {
+		file = file[:ext]
+	}
+	raw := []byte(file)
+	for i, v := range raw {
+		if v >= 'a' && v <= 'z' || v >= 'A' && v <= 'Z' || v >= '0' && v <= '9' {
+			continue
+		}
+		raw[i] = '_'
+	}
+	return string(raw)
+}
+
+func Tristate(v bool) TristateVal {
+	if v {
+		return TristateYes
+	}
+	return TristateNo
+}
+
+func (tv TristateVal) String() string {
+	switch tv {
+	case TristateYes:
+		return "true"
+	case TristateNo:
+		return "false"
+	default:
+		return "unknown"
+	}
+}
diff --git a/pkg/declextract/netlink.go b/pkg/declextract/netlink.go
index 0adec5bc4..1b49bbd63 100644
--- a/pkg/declextract/netlink.go
+++ b/pkg/declextract/netlink.go
@@ -47,7 +47,7 @@ func (ctx *context) serializeNetlink() {
 				Files:            []string{fam.SourceFile},
 				Func:             op.Func,
 				Access:           op.Access,
-				AutoDescriptions: true,
+				AutoDescriptions: TristateYes,
 			})
 		}