prog: remove special knowledge about "mmap" syscall

Abstract "mmap" away as it can be called differently on another OS.

8 files changed, 23 insertions, 19 deletions

diff --git a/prog/hints.go b/prog/hints.go
index e268d46a6..b295b2151 100644
--- a/prog/hints.go
+++ b/prog/hints.go
@@ -36,16 +36,7 @@ const (
 	maxDataLength = 100
 )
 
-var (
-	specialIntsSet uint64Set
-
-	// A set of calls for which hints should not be generated.
-	hintNamesBlackList = map[string]bool{
-		"mmap":  true,
-		"open":  true,
-		"close": true,
-	}
-)
+var specialIntsSet uint64Set
 
 func (m CompMap) AddComp(arg1, arg2 uint64) {
 	if _, ok := m[arg1]; !ok {
@@ -58,7 +49,7 @@ func (m CompMap) AddComp(arg1, arg2 uint64) {
 // For each of the mutants executes the exec callback.
 func (p *Prog) MutateWithHints(compMaps []CompMap, exec func(newP *Prog)) {
 	for i, c := range p.Calls {
-		if _, ok := hintNamesBlackList[c.Meta.CallName]; ok {
+		if c.Meta == defaultTarget.MmapSyscall {
 			continue
 		}
 		foreachArg(c, func(arg, _ Arg, _ *[]Arg) {
diff --git a/prog/mutation.go b/prog/mutation.go
index e793e28e4..d92c96361 100644
--- a/prog/mutation.go
+++ b/prog/mutation.go
@@ -55,7 +55,7 @@ func (p *Prog) Mutate(rs rand.Source, ncalls int, ct *ChoiceTable, corpus []*Pro
 				continue
 			}
 			// Mutating mmap() arguments almost certainly doesn't give us new coverage.
-			if c.Meta.Name == "mmap" && r.nOutOf(99, 100) {
+			if c.Meta == defaultTarget.MmapSyscall && r.nOutOf(99, 100) {
 				retry = true
 				continue
 			}
@@ -289,7 +289,7 @@ func Minimize(p0 *Prog, callIndex0 int, pred0 func(*Prog, int) bool, crash bool)
 		// Remove all mmaps.
 		for i := 0; i < len(p.Calls); i++ {
 			c := p.Calls[i]
-			if i != callIndex && c.Meta.Name == "mmap" {
+			if i != callIndex && c.Meta == defaultTarget.MmapSyscall {
 				p.removeCall(i)
 				if i < callIndex {
 					callIndex--
diff --git a/prog/prio.go b/prog/prio.go
index c64ae319b..e4a9b334f 100644
--- a/prog/prio.go
+++ b/prog/prio.go
@@ -141,7 +141,8 @@ func calcDynamicPrio(corpus []*Prog) [][]float32 {
 				id0 := c0.Meta.ID
 				id1 := c1.Meta.ID
 				// There are too many mmap's anyway.
-				if id0 == id1 || c0.Meta.Name == "mmap" || c1.Meta.Name == "mmap" {
+				if id0 == id1 || c0.Meta == defaultTarget.MmapSyscall ||
+					c1.Meta == defaultTarget.MmapSyscall {
 					continue
 				}
 				prios[id0][id1] += 1.0
diff --git a/prog/rand.go b/prog/rand.go
index 5526427f5..8439015e7 100644
--- a/prog/rand.go
+++ b/prog/rand.go
@@ -438,7 +438,7 @@ func (r *randGen) generateCall(s *state, p *Prog) []*Call {
 			c := p.Calls[r.Intn(len(p.Calls))].Meta
 			call = c.ID
 			// There is roughly half of mmap's so ignore them.
-			if c.Name != "mmap" {
+			if c != defaultTarget.MmapSyscall {
 				break
 			}
 		}
diff --git a/prog/target.go b/prog/target.go
index 4faded023..b8e76919d 100644
--- a/prog/target.go
+++ b/prog/target.go
@@ -18,6 +18,10 @@ type Target struct {
 	Syscalls  []*Syscall
 	Resources []*ResourceDesc
 
+	// Syscall used by MakeMmap.
+	// It has some special meaning because there are usually too many of them.
+	MmapSyscall *Syscall
+
 	// MakeMmap creates call that maps [start, start+npages) page range.
 	MakeMmap func(start, npages uint64) *Call
 
@@ -59,6 +63,10 @@ func RegisterTarget(target *Target) {
 	targets[key] = target
 }
 
+func GetTarget(OS, arch string) *Target {
+	return targets[OS+"/"+arch]
+}
+
 // SetDefaultTarget sets default target for prog package.
 // Majority of the code is not prepared for multiple targets,
 // so we use default target as a temporary measure.
@@ -72,10 +80,12 @@ func SetDefaultTarget(OS, arch string) error {
 		}
 		return fmt.Errorf("unknown target: %v (supported: %v)", key, supported)
 	}
-	if len(Syscalls) != 0 {
+	if defaultTarget != nil {
 		return fmt.Errorf("default target is already set")
 	}
 
+	defaultTarget = target
+
 	Syscalls = target.Syscalls
 	SyscallMap = target.syscallMap
 	Resources = target.resourceMap
@@ -124,6 +134,8 @@ var (
 	pageSize   uint64
 	dataOffset uint64
 
+	defaultTarget *Target
+
 	Syscalls      []*Syscall
 	SyscallMap    map[string]*Syscall
 	Resources     map[string]*ResourceDesc
diff --git a/sys/linux/init.go b/sys/linux/init.go
index 8d96ac27a..cbf93e963 100644
--- a/sys/linux/init.go
+++ b/sys/linux/init.go
@@ -20,6 +20,7 @@ func initArch(syscalls []*prog.Syscall, resources []*prog.ResourceDesc,
 		DataOffset:   dataOffset,
 		Syscalls:     syscalls,
 		Resources:    resources,
+		MmapSyscall:  arch.mmapSyscall,
 		MakeMmap:     arch.makeMmap,
 		AnalyzeMmap:  arch.analyzeMmap,
 		SanitizeCall: arch.sanitizeCall,
diff --git a/syz-manager/manager.go b/syz-manager/manager.go
index 3d8933e81..a7216b709 100644
--- a/syz-manager/manager.go
+++ b/syz-manager/manager.go
@@ -121,6 +121,8 @@ func main() {
 	if err != nil {
 		Fatalf("%v", err)
 	}
+	// mmap is used to allocate memory.
+	syscalls[prog.GetTarget(cfg.TargetOS, cfg.TargetArch).MmapSyscall.ID] = true
 	initAllCover(cfg.Vmlinux)
 	RunManager(cfg, syscalls)
 }
diff --git a/syz-manager/mgrconfig/mgrconfig.go b/syz-manager/mgrconfig/mgrconfig.go
index 75df7e4dd..1f9819154 100644
--- a/syz-manager/mgrconfig/mgrconfig.go
+++ b/syz-manager/mgrconfig/mgrconfig.go
@@ -206,9 +206,6 @@ func ParseEnabledSyscalls(cfg *Config) (map[int]bool, error) {
 			return nil, fmt.Errorf("unknown disabled syscall: %v", c)
 		}
 	}
-	// mmap is used to allocate memory.
-	syscalls[prog.SyscallMap["mmap"].ID] = true
-
 	return syscalls, nil
 }