sys/openbsd: disable mknod sanitization as tests fail

TestSerializeDeserializeRandom fails from time to time
because program is different after we serialize/deserialize it.
Turns out openbsd SanitizeCall is not idempotent.
Add a test for this and disable the logic for now.

2 files changed, 37 insertions, 18 deletions

diff --git a/prog/prog_test.go b/prog/prog_test.go
index 967b93210..29b4d385e 100644
--- a/prog/prog_test.go
+++ b/prog/prog_test.go
@@ -397,3 +397,19 @@ fallback$0()
 		})
 	}
 }
+
+func TestSanitizeRandom(t *testing.T) {
+	testEachTargetRandom(t, func(t *testing.T, target *Target, rs rand.Source, iters int) {
+		for i := 0; i < iters; i++ {
+			p := target.Generate(rs, 10, nil)
+			s0 := string(p.Serialize())
+			for _, c := range p.Calls {
+				target.SanitizeCall(c)
+			}
+			s1 := string(p.Serialize())
+			if s0 != s1 {
+				t.Fatalf("non-sanitized program or non-idempotent sanitize\nwas: %v\ngot: %v", s0, s1)
+			}
+		}
+	})
+}
diff --git a/sys/openbsd/init.go b/sys/openbsd/init.go
index ac06ad644..3f4641405 100644
--- a/sys/openbsd/init.go
+++ b/sys/openbsd/init.go
@@ -26,24 +26,27 @@ func (arch *arch) SanitizeCall(c *prog.Call) {
 
 	// Prevent vnodes of type VBAD from being created. Such vnodes will
 	// likely trigger assertion errors by the kernel.
-	pos := 1
-	switch c.Meta.CallName {
-	case "mknodat":
-		pos = 2
-		fallthrough
-	case "mknod":
-		mode := c.Args[pos].(*prog.ConstArg)
-		if (mode.Val & arch.unix.S_IFMT) != arch.unix.S_IFMT {
-			return
-		}
-		saneMode := mode.Val & ^arch.unix.S_IFMT
-		switch {
-		case (mode.Val & arch.unix.S_IFCHR) == arch.unix.S_IFCHR:
-			mode.Val = saneMode | arch.unix.S_IFCHR
-		case (mode.Val & arch.unix.S_IFBLK) == arch.unix.S_IFBLK:
-			mode.Val = saneMode | arch.unix.S_IFBLK
-		case (mode.Val & arch.unix.S_IFIFO) == arch.unix.S_IFIFO:
-			mode.Val = saneMode | arch.unix.S_IFIFO
+	// TODO(dvyukov): this is disabled for now because TestSanitizeRandom fails.
+	if false {
+		pos := 1
+		switch c.Meta.CallName {
+		case "mknodat":
+			pos = 2
+			fallthrough
+		case "mknod":
+			mode := c.Args[pos].(*prog.ConstArg)
+			if mode.Val&arch.unix.S_IFMT != arch.unix.S_IFMT {
+				return
+			}
+			saneMode := mode.Val & ^arch.unix.S_IFMT
+			switch {
+			case mode.Val&arch.unix.S_IFCHR == arch.unix.S_IFCHR:
+				mode.Val = saneMode | arch.unix.S_IFCHR
+			case mode.Val&arch.unix.S_IFBLK == arch.unix.S_IFBLK:
+				mode.Val = saneMode | arch.unix.S_IFBLK
+			case mode.Val&arch.unix.S_IFIFO == arch.unix.S_IFIFO:
+				mode.Val = saneMode | arch.unix.S_IFIFO
+			}
 		}
 	}
 }