pkg/csource: exclude auto-generated syscalls from tests

Auto-generated syscall descriptions currently do not properly mark
arch-specific syscalls like socketcall (which is only available on 32
bit systems), which leads to TestGenerate breakages.

Until the syz-declextract tool is fixed and descriptions are
re-generated, don't use such calls in TestGenerate tests. It has
recently caused numerous syzkaller update erorrs on syzbot.

Cc #5410.
Closes #6468.

Author: a-nogikh

pkg/csource/csource_test.go

@@ -38,6 +38,10 @@ func TestGenerate(t *testing.T) {
 	t.Parallel()
 	checked := make(map[string]bool)
 	for _, target := range prog.AllTargets() {
+		// Auto-generated descriptions currently do not properly mark arch-specific syscalls, see
+		// https://github.com/google/syzkaller/issues/5410#issuecomment-3570190241.
+		// Until it's fixed, let's remove these syscalls from csource tests.
+		ct := target.NoAutoChoiceTable()
 		sysTarget := targets.Get(target.OS, target.Arch)
 		if runtime.GOOS != sysTarget.BuildOS {
 			continue
@@ -50,32 +54,32 @@ func TestGenerate(t *testing.T) {
 			if full || !testing.Short() {
 				checked[target.OS] = true
 				t.Parallel()
-				testTarget(t, target, full)
+				testTarget(t, target, full, ct)
 			}
-			testPseudoSyscalls(t, target)
+			testPseudoSyscalls(t, target, ct)
 		})
 	}
 }
 
-func testPseudoSyscalls(t *testing.T, target *prog.Target) {
+func testPseudoSyscalls(t *testing.T, target *prog.Target, ct *prog.ChoiceTable) {
 	// Use options that are as minimal as possible.
 	// We want to ensure that the code can always be compiled.
 	opts := Options{
 		Slowdown: 1,
 	}
 	rs := testutil.RandSource(t)
 	for _, meta := range target.PseudoSyscalls() {
-		p := target.GenSampleProg(meta, rs)
+		p := target.GenSampleProg(meta, rs, ct)
 		t.Run(fmt.Sprintf("single_%s", meta.CallName), func(t *testing.T) {
 			t.Parallel()
 			testOne(t, p, opts)
 		})
 	}
 }
 
-func testTarget(t *testing.T, target *prog.Target, full bool) {
+func testTarget(t *testing.T, target *prog.Target, full bool, ct *prog.ChoiceTable) {
 	rs := testutil.RandSource(t)
-	p := target.Generate(rs, 10, target.DefaultChoiceTable())
+	p := target.Generate(rs, 10, ct)
 	// Turns out that fully minimized program can trigger new interesting warnings,
 	// e.g. about NULL arguments for functions that require non-NULL arguments in syz_ functions.
 	// We could append both AllSyzProg as-is and a minimized version of it,

prog/rand.go

@@ -670,9 +670,9 @@ func (target *Target) PseudoSyscalls() []*Syscall {
 }
 
 // GenSampleProg generates a single sample program for the call.
-func (target *Target) GenSampleProg(meta *Syscall, rs rand.Source) *Prog {
+func (target *Target) GenSampleProg(meta *Syscall, rs rand.Source, ct *ChoiceTable) *Prog {
 	r := newRand(target, rs)
-	s := newState(target, target.DefaultChoiceTable(), nil)
+	s := newState(target, ct, nil)
 	p := &Prog{
 		Target: target,
 	}

prog/target.go

@@ -370,6 +370,17 @@ func (target *Target) DefaultChoiceTable() *ChoiceTable {
 	return target.defaultChoiceTable
 }
 
+func (target *Target) NoAutoChoiceTable() *ChoiceTable {
+	calls := map[*Syscall]bool{}
+	for _, c := range target.Syscalls {
+		if c.Attrs.Automatic {
+			continue
+		}
+		calls[c] = true
+	}
+	return target.BuildChoiceTable(nil, calls)
+}
+
 func (target *Target) RequiredGlobs() []string {
 	globs := make(map[string]bool)
 	ForeachType(target.Syscalls, func(typ Type, ctx *TypeCtx) {