AI Trajectory


Trajectory: (Expand/Collapse All)
Seq Timestamp Type Name Duration
0/0 2026/06/22 17:55 flow patch-triage
0m Args: 
null

Results: 
{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch introduces a safe Rust wrapper for `synchronize_rcu()` and replaces existing unsafe FFI calls with this new wrapper. It does not change the functional logic or execution flow of the kernel.",
  "WorthFuzzing": false
}
1/1 2026/06/22 17:55 action read-patch-diff
0m Args: 
null

Results: 
{
  "PatchDiff": "commit a845741008ab6482fb08c711ebba9578ec8a43c7\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Mon Jun 22 17:55:41 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs\nindex 0f4ae673256d56..f539603349f1cb 100644\n--- a/rust/kernel/revocable.rs\n+++ b/rust/kernel/revocable.rs\n@@ -7,7 +7,11 @@\n \n use pin_init::Wrapper;\n \n-use crate::{bindings, prelude::*, sync::rcu, types::Opaque};\n+use crate::{\n+    prelude::*,\n+    sync::rcu,\n+    types::Opaque, //\n+};\n use core::{\n     marker::PhantomData,\n     ops::Deref,\n@@ -161,8 +165,7 @@ unsafe fn revoke_internal\u003cconst SYNC: bool\u003e(\u0026self) -\u003e bool {\n \n         if revoke {\n             if SYNC {\n-                // SAFETY: Just an FFI call, there are no further requirements.\n-                unsafe { bindings::synchronize_rcu() };\n+                rcu::synchronize_rcu();\n             }\n \n             // SAFETY: We know `self.data` is valid because only one CPU can succeed the\ndiff --git a/rust/kernel/sync/poll.rs b/rust/kernel/sync/poll.rs\nindex 0ec985d560c8d3..30ebeea1702f99 100644\n--- a/rust/kernel/sync/poll.rs\n+++ b/rust/kernel/sync/poll.rs\n@@ -8,7 +8,11 @@\n     bindings,\n     fs::File,\n     prelude::*,\n-    sync::{CondVar, LockClassKey},\n+    sync::{\n+        CondVar,\n+        LockClassKey,\n+        rcu::synchronize_rcu, //\n+    }, //\n };\n use core::{marker::PhantomData, ops::Deref};\n \n@@ -99,8 +103,6 @@ fn drop(self: Pin\u003c\u0026mut Self\u003e) {\n         unsafe { bindings::__wake_up_pollfree(self.inner.wait_queue_head.get()) };\n \n         // Wait for epoll items to be properly removed.\n-        //\n-        // SAFETY: Just an FFI call.\n-        unsafe { bindings::synchronize_rcu() };\n+        synchronize_rcu();\n     }\n }\ndiff --git a/rust/kernel/sync/rcu.rs b/rust/kernel/sync/rcu.rs\nindex a32bef6e490b0e..0d438ef3176635 100644\n--- a/rust/kernel/sync/rcu.rs\n+++ b/rust/kernel/sync/rcu.rs\n@@ -50,3 +50,12 @@ fn drop(\u0026mut self) {\n pub fn read_lock() -\u003e Guard {\n     Guard::new()\n }\n+\n+/// Wait for one RCU grace period.\n+///\n+/// You typically do this to wait for everyone holding a [`Guard`].\n+#[inline]\n+pub fn synchronize_rcu() {\n+    // SAFETY: `synchronize_rcu()` is always safe to be called. It just waits for a grace period.\n+    unsafe { bindings::synchronize_rcu() };\n+}\n"
}
2/1 2026/06/22 17:55 agent patch-evaluator
0m Model: 
gemini-3.1-pro-preview

Args: 
null

Results: 
{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch introduces a safe Rust wrapper for `synchronize_rcu()` and replaces existing unsafe FFI calls with this new wrapper. It does not change the functional logic or execution flow of the kernel.",
  "WorthFuzzing": false
}

Instruction: 
You are an expert Linux kernel maintainer.
Your job is to review a provided patch series and determine
if it makes functional changes to the kernel that should be fuzzed.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively
use your code access tools to examine the actual source code and confirm any assumptions.

Return WorthFuzzing=false if the patch only contains:
- Modifications to Documentation/, Kconfig files, or code comments.
- Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints.
- Changes to numeric constants or macros that do not functionally alter execution flow.
- Code paths that are impossible to reach in virtualized environments like GCE or QEMU,
even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim).

If it modifies reachable core kernel logic, drivers, or architectures, use your code search
tools to verify the code can be executed, then return WorthFuzzing=true.

When returning WorthFuzzing=true, you MUST ALSO:
1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols.
   Avoid listing generic hot-path functions to prevent skewed test distributions.
2. Identify any specific CONFIG_ options required to properly test this new/modified feature.
   Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions.
   Do not list too generic configs (we already have them enabled). Only list those that
   specifically cover the modified code. List them in the EnableConfigs output array,
   and DO NOT add a 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4").
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

Prompt: 
For your convenience, here is the diff of the changes:
commit a845741008ab6482fb08c711ebba9578ec8a43c7
Author: syz-cluster <triage@syzkaller.com>
Date:   Mon Jun 22 17:55:41 2026 +0000

    syz-cluster: applied patch under review

diff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs
index 0f4ae673256d56..f539603349f1cb 100644
--- a/rust/kernel/revocable.rs
+++ b/rust/kernel/revocable.rs
@@ -7,7 +7,11 @@
 
 use pin_init::Wrapper;
 
-use crate::{bindings, prelude::*, sync::rcu, types::Opaque};
+use crate::{
+    prelude::*,
+    sync::rcu,
+    types::Opaque, //
+};
 use core::{
     marker::PhantomData,
     ops::Deref,
@@ -161,8 +165,7 @@ unsafe fn revoke_internal<const SYNC: bool>(&self) -> bool {
 
         if revoke {
             if SYNC {
-                // SAFETY: Just an FFI call, there are no further requirements.
-                unsafe { bindings::synchronize_rcu() };
+                rcu::synchronize_rcu();
             }
 
             // SAFETY: We know `self.data` is valid because only one CPU can succeed the
diff --git a/rust/kernel/sync/poll.rs b/rust/kernel/sync/poll.rs
index 0ec985d560c8d3..30ebeea1702f99 100644
--- a/rust/kernel/sync/poll.rs
+++ b/rust/kernel/sync/poll.rs
@@ -8,7 +8,11 @@
     bindings,
     fs::File,
     prelude::*,
-    sync::{CondVar, LockClassKey},
+    sync::{
+        CondVar,
+        LockClassKey,
+        rcu::synchronize_rcu, //
+    }, //
 };
 use core::{marker::PhantomData, ops::Deref};
 
@@ -99,8 +103,6 @@ fn drop(self: Pin<&mut Self>) {
         unsafe { bindings::__wake_up_pollfree(self.inner.wait_queue_head.get()) };
 
         // Wait for epoll items to be properly removed.
-        //
-        // SAFETY: Just an FFI call.
-        unsafe { bindings::synchronize_rcu() };
+        synchronize_rcu();
     }
 }
diff --git a/rust/kernel/sync/rcu.rs b/rust/kernel/sync/rcu.rs
index a32bef6e490b0e..0d438ef3176635 100644
--- a/rust/kernel/sync/rcu.rs
+++ b/rust/kernel/sync/rcu.rs
@@ -50,3 +50,12 @@ fn drop(&mut self) {
 pub fn read_lock() -> Guard {
     Guard::new()
 }
+
+/// Wait for one RCU grace period.
+///
+/// You typically do this to wait for everyone holding a [`Guard`].
+#[inline]
+pub fn synchronize_rcu() {
+    // SAFETY: `synchronize_rcu()` is always safe to be called. It just waits for a grace period.
+    unsafe { bindings::synchronize_rcu() };
+}

3/2 2026/06/22 17:55 llm patch-evaluator
0m Model: 
gemini-3.1-pro-preview

Args: 
null

Results: 
null

Tokens: 
							input: 2433
							output: 72
							thoughts: 517

Thoughts: 
**Refactoring for Safety: `synchronize_rcu()` in Rust Kernel Code**

Okay, so I'm looking at this patch and, from a quick glance, it's a straightforward refactoring in the Rust kernel code. My initial assessment is that it seems localized and focused on enhancing safety. Specifically, it's replacing direct `unsafe` calls to `bindings::synchronize_rcu()` with a safe Rust wrapper, `rcu::synchronize_rcu()`. This is happening in `revocable.rs` and `poll.rs`, and it looks like the wrapper itself has been added in `rcu.rs`. The code appears sound and the comments are clear about the "wait for one RCU grace period".

I've just scanned the diff... Yup, that's exactly what's happening. The function, as expected, is a thin layer, re-exposing the underlying FFI call, but it does so behind a safe Rust API, which is good practice.

Now, considering the implications for fuzzing... given that the underlying logic remains unchanged, the execution flow is identical, and this is purely a change in the *how* of the call, not the *what*, I'm going to say this patch *doesn't* introduce any new surface area worth fuzzing. The functional behavior of the kernel is untouched. Therefore, `WorthFuzzing` should definitely be set to `false`. It's a clean refactoring for increased safety, but not a functional change warranting further fuzzing effort.

4/2 2026/06/22 17:55 tool set-results
0m Args: 
{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch introduces a safe Rust wrapper for `synchronize_rcu()` and replaces existing unsafe FFI calls with this new wrapper. It does not change the functional logic or execution flow of the kernel.",
  "WorthFuzzing": false
}

Results: 
{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch introduces a safe Rust wrapper for `synchronize_rcu()` and replaces existing unsafe FFI calls with this new wrapper. It does not change the functional logic or execution flow of the kernel.",
  "WorthFuzzing": false
}
LLM Calls Summary:
Total Calls Total Tokens Avg Tokens Total Duration (Seconds) Avg Duration (Seconds)
Tool Calls Summary:
Total Calls Total Duration (Seconds) Avg Duration (Seconds)