pkg/aflow/flow/patching: use recent commit subjects

Give LLM the recent commit subjects when it generates description,
so that it can use the same style.

Add infrastrcuture to write end-to-end action tests to test it.

8 files changed, 163 insertions, 11 deletions

diff --git a/pkg/aflow/flow.go b/pkg/aflow/flow.go
index 467e28880..960c034dc 100644
--- a/pkg/aflow/flow.go
+++ b/pkg/aflow/flow.go
@@ -63,14 +63,7 @@ func register[Inputs, Outputs any](typ ai.WorkflowType, description string,
 			_, err := convertFromMap[Inputs](inputs, false, false)
 			return err
 		},
-		extractOutputs: func(state map[string]any) map[string]any {
-			// Ensure that we actually have all outputs.
-			tmp, err := convertFromMap[Outputs](state, false, false)
-			if err != nil {
-				panic(err)
-			}
-			return convertToMap(tmp)
-		},
+		extractOutputs: extractOutputs[Outputs],
 	}
 	for _, flow := range flows {
 		if flow.Name == "" {
diff --git a/pkg/aflow/flow/patching/actions.go b/pkg/aflow/flow/patching/actions.go
index 2c98e9306..d42c24fa1 100644
--- a/pkg/aflow/flow/patching/actions.go
+++ b/pkg/aflow/flow/patching/actions.go
@@ -4,6 +4,8 @@
 package patching
 
 import (
+	"errors"
+	"fmt"
 	"os/exec"
 	"path/filepath"
 	"strings"
@@ -108,3 +110,33 @@ func maintainers(ctx *aflow.Context, args maintainersArgs) (maintainersResult, e
 	}
 	return res, nil
 }
+
+var getRecentCommits = aflow.NewFuncAction("get-recent-commits", recentCommits)
+
+type recentCommitsArgs struct {
+	KernelSrc    string
+	KernelCommit string
+	PatchDiff    string
+}
+
+type recentCommitsResult struct {
+	RecentCommits string
+}
+
+func recentCommits(ctx *aflow.Context, args recentCommitsArgs) (recentCommitsResult, error) {
+	var res recentCommitsResult
+	var files []string
+	for _, file := range vcs.ParseGitDiff([]byte(args.PatchDiff)) {
+		files = append(files, file.Name)
+	}
+	if len(files) == 0 {
+		return res, aflow.FlowError(errors.New("patch diff does not contain any modified files"))
+	}
+	gitArgs := append([]string{"log", "--format=%s", "--no-merges", "-n", "20", args.KernelCommit}, files...)
+	output, err := osutil.RunCmd(10*time.Minute, args.KernelSrc, "git", gitArgs...)
+	if err != nil {
+		return res, aflow.FlowError(fmt.Errorf("%w\n%s", err, output))
+	}
+	res.RecentCommits = string(output)
+	return res, nil
+}
diff --git a/pkg/aflow/flow/patching/actions_test.go b/pkg/aflow/flow/patching/actions_test.go
new file mode 100644
index 000000000..c6f3011e7
--- /dev/null
+++ b/pkg/aflow/flow/patching/actions_test.go
@@ -0,0 +1,59 @@
+// Copyright 2026 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package patching
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/google/syzkaller/pkg/aflow"
+)
+
+func TestRecentCommits(t *testing.T) {
+	// To avoid creating a fake git repo, we use the syzkaller repo itself.
+	// On CI we have a shallow git checkout that does not have the commit.
+	if os.Getenv("CI") != "" {
+		t.Skip("skipping on CI because of shallow git checkout")
+	}
+	aflow.TestAction(t, getRecentCommits, recentCommitsArgs{
+		KernelSrc:    filepath.FromSlash("../../../.."),
+		KernelCommit: "e01a0ca6c12c9851ea7090f13879255ef82291e7",
+		PatchDiff: `
+diff --git a/dashboard/app/ai.go b/dashboard/app/ai.go
+index d4539113c..1d7401e61 100644
+--- a/dashboard/app/ai.go
++++ b/dashboard/app/ai.go
+@@ -1,2 +1,2 @@
+-// Copyright 2025 syzkaller project authors. All rights reserved.
++// Copyright 2026 syzkaller project authors. All rights reserved.
+ // Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+diff --git a/syz-cluster/pkg/fuzzconfig/generate.go b/syz-cluster/pkg/fuzzconfig/generate.go
+index fa7d082e6..74ec57b49 100644
+--- a/syz-cluster/pkg/fuzzconfig/generate.go
++++ b/syz-cluster/pkg/fuzzconfig/generate.go
+@@ -1,2 +1,2 @@
+-// Copyright 2025 syzkaller project authors. All rights reserved.
++// Copyright 2026 syzkaller project authors. All rights reserved.
+ // Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+`,
+	}, recentCommitsResult{RecentCommits: `dashboard: run patching ai jobs on custom base commits
+dashboard/app: upload AI-generated patches to gerrit
+dashboard: journal user actions on the ai dashboard
+pkg/aflow/trajectory: add token usage
+dashboard/app: add AI job running status
+dashboard: filter AI jobs by workflows
+syz-cluster: disable some trace calls for non-bpf targets
+pkg/aflow: make LLM model per-agent rather than per-flow
+dashboard/app: show crash report on AI job page
+dashboard/app: improve AI UI
+pkg/aflow: allow to specify model per-flow
+dashboard/app: add race harmfullness label
+dashboard/app: add manual AI job triage
+pkg/aflow/flow/assessment: add UAF moderation workflow
+dashboard/app: add support for AI workflows
+syz-cluster: rewrite fuzz config generation
+`,
+	}, "")
+}
diff --git a/pkg/aflow/flow/patching/patching.go b/pkg/aflow/flow/patching/patching.go
index 1906204ec..f8ee75a31 100644
--- a/pkg/aflow/flow/patching/patching.go
+++ b/pkg/aflow/flow/patching/patching.go
@@ -75,6 +75,7 @@ func createPatchingFlow(name string, summaryWindow int) *aflow.Flow {
 				MaxIterations: 10,
 			},
 			getMaintainers,
+			getRecentCommits,
 			&aflow.LLMAgent{
 				Name:          "description-generator",
 				Model:         aflow.BestExpensiveModel,
@@ -222,6 +223,12 @@ Additional description of the patch:
 
 {{.PatchExplanation}}
 
+Here are summaries of recent commits that touched the same files.
+Format the summary line consistently with these, look how prefixes
+are specified, letter capitalization, style, etc. 
+
+{{.RecentCommits}}
+
 {{if titleIsWarning .BugTitle}}
 If the patch removes the WARN_ON macro, refer to the fact that WARN_ON
 must not be used for conditions that can legitimately happen, and that pr_err
diff --git a/pkg/aflow/func_action.go b/pkg/aflow/func_action.go
index 4b6fe11f1..bcc9e5592 100644
--- a/pkg/aflow/func_action.go
+++ b/pkg/aflow/func_action.go
@@ -5,8 +5,11 @@ package aflow
 
 import (
 	"maps"
+	"reflect"
+	"testing"
 
 	"github.com/google/syzkaller/pkg/aflow/trajectory"
+	"github.com/stretchr/testify/require"
 )
 
 func NewFuncAction[Args, Results any](name string, fn func(*Context, Args) (Results, error)) Action {
@@ -44,3 +47,13 @@ func (a *funcAction[Args, Results]) verify(ctx *verifyContext) {
 	requireInputs[Args](ctx, a.name)
 	provideOutputs[Results](ctx, a.name)
 }
+
+func (a *funcAction[Args, Results]) testVerify(t *testing.T, ctx *verifyContext, args, results any) (
+	map[string]any, map[string]any, func(map[string]any) map[string]any) {
+	require.Equal(t, reflect.TypeFor[Args](), reflect.TypeOf(args))
+	require.Equal(t, reflect.TypeFor[Results](), reflect.TypeOf(results))
+	provideOutputs[Args](ctx, "args")
+	a.verify(ctx)
+	requireInputs[Results](ctx, "results")
+	return convertToMap(args.(Args)), convertToMap(results.(Results)), extractOutputs[Results]
+}
diff --git a/pkg/aflow/schema.go b/pkg/aflow/schema.go
index 8c96578a7..52924d99a 100644
--- a/pkg/aflow/schema.go
+++ b/pkg/aflow/schema.go
@@ -151,6 +151,15 @@ func setField(field reflect.Value, val, f any, name string, tool bool) error {
 		val, name, f, field.Type().Name())
 }
 
+func extractOutputs[T any](state map[string]any) map[string]any {
+	// Ensure that we actually have all outputs.
+	tmp, err := convertFromMap[T](state, false, false)
+	if err != nil {
+		panic(err)
+	}
+	return convertToMap(tmp)
+}
+
 // foreachField iterates over all public fields of the struct provided in data.
 func foreachField(data any) iter.Seq2[string, reflect.Value] {
 	return func(yield func(string, reflect.Value) bool) {
diff --git a/pkg/aflow/test_action.go b/pkg/aflow/test_action.go
new file mode 100644
index 000000000..0bf49ed69
--- /dev/null
+++ b/pkg/aflow/test_action.go
@@ -0,0 +1,41 @@
+// Copyright 2026 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package aflow
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/syzkaller/pkg/aflow/trajectory"
+	"github.com/stretchr/testify/require"
+)
+
+func TestAction(t *testing.T, a Action, initArgs, wantResults any, wantError string) {
+	type tester interface {
+		testVerify(t *testing.T, ctx *verifyContext, args, results any) (
+			map[string]any, map[string]any, func(map[string]any) map[string]any)
+	}
+	vctx := newVerifyContext()
+	args, results, extractOutputs := a.(tester).testVerify(t, vctx, initArgs, wantResults)
+	require.NoError(t, vctx.finalize())
+	// We don't init all fields, init more, if necessary.
+	ctx := &Context{
+		state:   args,
+		onEvent: func(*trajectory.Span) error { return nil },
+		stubContext: stubContext{
+			timeNow: time.Now,
+		},
+	}
+	defer ctx.close()
+	err := a.execute(ctx)
+	gotResults := map[string]any{}
+	gotError := ""
+	if err != nil {
+		gotError = err.Error()
+	} else {
+		gotResults = extractOutputs(ctx.state)
+	}
+	require.Equal(t, wantError, gotError)
+	require.Equal(t, results, gotResults)
+}
diff --git a/pkg/aflow/test_tool.go b/pkg/aflow/test_tool.go
index 4b9cb6a4a..a4755d639 100644
--- a/pkg/aflow/test_tool.go
+++ b/pkg/aflow/test_tool.go
@@ -17,9 +17,7 @@ func TestTool(t *testing.T, tool Tool, initState, initArgs, wantResults any, wan
 	vctx := newVerifyContext()
 	state, args, results := tool.(toolTester).checkTestTypes(t, vctx, initState, initArgs, wantResults)
 	tool.verify(vctx)
-	if err := vctx.finalize(); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, vctx.finalize())
 	// Just ensure it does not crash.
 	_ = tool.declaration()
 	// We don't init all fields, init more, if necessary.