Update unimpl.EmitUnimplementedEvent interface to add the syscall number.

This catches up the interface to the `EmitUnimplementedEvent` method signature
on `kernel.Kernel`.

Also add build-time test to verify that `kernel.Kernel` implements this
interface, in order to catch such breakages at build time in the future.

PiperOrigin-RevId: 519000411

pkg/sentry/unimpl/BUILD

@@ -1,4 +1,4 @@
-load("//tools:defs.bzl", "go_library", "proto_library")
+load("//tools:defs.bzl", "go_library", "go_test", "proto_library")
 
 package(
     default_applicable_licenses = ["//:license"],
@@ -21,3 +21,12 @@ go_library(
         "//pkg/log",
     ],
 )
+
+go_test(
+    name = "events_test",
+    srcs = ["events_test.go"],
+    deps = [
+        ":unimpl",
+        "//pkg/sentry/kernel",
+    ],
+)

pkg/sentry/unimpl/events.go

@@ -31,15 +31,15 @@ const (
 
 // Events interface defines method to emit unsupported events.
 type Events interface {
-	EmitUnimplementedEvent(context.Context)
+	EmitUnimplementedEvent(ctx context.Context, sysno uintptr)
 }
 
 // EmitUnimplementedEvent emits unsupported syscall event to the context.
-func EmitUnimplementedEvent(ctx context.Context) {
+func EmitUnimplementedEvent(ctx context.Context, sysno uintptr) {
 	e := ctx.Value(CtxEvents)
 	if e == nil {
 		log.Warningf("Context.Value(CtxEvents) not present, unimplemented syscall event not reported.")
 		return
 	}
-	e.(Events).EmitUnimplementedEvent(ctx)
+	e.(Events).EmitUnimplementedEvent(ctx, sysno)
 }

pkg/sentry/unimpl/events_test.go

@@ -0,0 +1,28 @@
+// Copyright 2023 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package events_test verifies that kernel.Kernel implements interface unimpl.Events.
+package events_test
+
+import (
+	"testing"
+
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sentry/unimpl"
+)
+
+// TestInterfaceMatch verifies that kernel.Kernel implements interface unimpl.Events.
+func TestInterfaceMatch(t *testing.T) {
+	var _ = (unimpl.Events)((*kernel.Kernel)(nil))
+}