AI Trajectory


Trajectory: (Expand/Collapse All)
Seq Timestamp Type Name Duration
0/0 2026/07/22 21:02 flow patch-triage
0m Args: 
null

Results: 
{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies a selftest tool (tools/testing/selftests/net/tcp_mmap.c) and does not change any kernel code.",
  "WorthFuzzing": false
}
1/1 2026/07/22 21:02 action read-patch-diff
0m Args: 
null

Results: 
{
  "PatchDiff": "commit 88c787770bfa324d96d641da2e5f5bcd5f82266a\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Wed Jul 22 21:02:37 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c\nindex 2544ae35d07a83..487ae659a1f183 100644\n--- a/tools/testing/selftests/net/tcp_mmap.c\n+++ b/tools/testing/selftests/net/tcp_mmap.c\n@@ -141,12 +141,12 @@ static void *mmap_large_buffer(size_t need, size_t *allocated)\n \tbuffer = mmap(NULL, sz, PROT_READ | PROT_WRITE,\n \t\t      MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);\n \n-\tif (buffer == (void *)-1) {\n+\tif (buffer == MAP_FAILED) {\n \t\tsz = need;\n \t\tbuffer = mmap(NULL, sz, PROT_READ | PROT_WRITE,\n \t\t\t      MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE,\n \t\t\t      -1, 0);\n-\t\tif (buffer != (void *)-1)\n+\t\tif (buffer != MAP_FAILED)\n \t\t\tfprintf(stderr, \"MAP_HUGETLB attempt failed, look at /sys/kernel/mm/hugepages for optimal performance\\n\");\n \t}\n \t*allocated = sz;\n@@ -189,13 +189,13 @@ void *child_thread(void *arg)\n \n \tfcntl(fd, F_SETFL, O_NDELAY);\n \tbuffer = mmap_large_buffer(chunk_size, \u0026buffer_sz);\n-\tif (buffer == (void *)-1) {\n+\tif (buffer == MAP_FAILED) {\n \t\tperror(\"mmap\");\n \t\tgoto error;\n \t}\n \tif (zflg) {\n \t\traddr = mmap(NULL, chunk_size + map_align, PROT_READ, flags, fd, 0);\n-\t\tif (raddr == (void *)-1) {\n+\t\tif (raddr == MAP_FAILED) {\n \t\t\tperror(\"mmap\");\n \t\t\tzflg = 0;\n \t\t} else {\n@@ -547,7 +547,7 @@ int main(int argc, char *argv[])\n \t}\n \n \tbuffer = mmap_large_buffer(chunk_size, \u0026buffer_sz);\n-\tif (buffer == (unsigned char *)-1) {\n+\tif (buffer == MAP_FAILED) {\n \t\tperror(\"mmap\");\n \t\texit(1);\n \t}\n"
}
2/1 2026/07/22 21:02 agent patch-evaluator
0m Model: 
best-expensive

Args: 
null

Results: 
{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies a selftest tool (tools/testing/selftests/net/tcp_mmap.c) and does not change any kernel code.",
  "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 88c787770bfa324d96d641da2e5f5bcd5f82266a
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Jul 22 21:02:37 2026 +0000

    syz-cluster: applied patch under review

diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c
index 2544ae35d07a83..487ae659a1f183 100644
--- a/tools/testing/selftests/net/tcp_mmap.c
+++ b/tools/testing/selftests/net/tcp_mmap.c
@@ -141,12 +141,12 @@ static void *mmap_large_buffer(size_t need, size_t *allocated)
 	buffer = mmap(NULL, sz, PROT_READ | PROT_WRITE,
 		      MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
 
-	if (buffer == (void *)-1) {
+	if (buffer == MAP_FAILED) {
 		sz = need;
 		buffer = mmap(NULL, sz, PROT_READ | PROT_WRITE,
 			      MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE,
 			      -1, 0);
-		if (buffer != (void *)-1)
+		if (buffer != MAP_FAILED)
 			fprintf(stderr, "MAP_HUGETLB attempt failed, look at /sys/kernel/mm/hugepages for optimal performance\n");
 	}
 	*allocated = sz;
@@ -189,13 +189,13 @@ void *child_thread(void *arg)
 
 	fcntl(fd, F_SETFL, O_NDELAY);
 	buffer = mmap_large_buffer(chunk_size, &buffer_sz);
-	if (buffer == (void *)-1) {
+	if (buffer == MAP_FAILED) {
 		perror("mmap");
 		goto error;
 	}
 	if (zflg) {
 		raddr = mmap(NULL, chunk_size + map_align, PROT_READ, flags, fd, 0);
-		if (raddr == (void *)-1) {
+		if (raddr == MAP_FAILED) {
 			perror("mmap");
 			zflg = 0;
 		} else {
@@ -547,7 +547,7 @@ int main(int argc, char *argv[])
 	}
 
 	buffer = mmap_large_buffer(chunk_size, &buffer_sz);
-	if (buffer == (unsigned char *)-1) {
+	if (buffer == MAP_FAILED) {
 		perror("mmap");
 		exit(1);
 	}

3/2 2026/07/22 21:02 llm patch-evaluator
0m Model: 
gemini-3.1-pro-preview

Args: 
null

Results: 
null

Tokens: 
							input: 2351
							output: 65
							thoughts: 301

Thoughts: 
**Analyzing a Selftest Patch**

Okay, so I'm looking at this patch for `tools/testing/selftests/net/tcp_mmap.c`. Immediately, I see it's a selftest, which is good. This means it's part of the user-space testing infrastructure and *not* core kernel code. That's a key distinction right away.

The patch itself is straightforward. It's replacing instances of `(void *)-1` and `(unsigned char *)-1` with `MAP_FAILED` in the mmap return value checks. This is a common and usually safer practice, aligning with standard library definitions and likely intended for better portability and clarity.

I've taken a quick look at the diff just to make sure; looks right. The change is confined to this selftest file.

Since this is a change solely within a testing tool, there's no impact on the kernel itself, no new functionality. Therefore, fuzzing this particular patch is not a productive use of resources. This change is purely for test code.

I'm confident in calling this "WorthFuzzing: false." Let's update the results.

4/2 2026/07/22 21:02 tool set-results
0m Args: 
{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies a selftest tool (tools/testing/selftests/net/tcp_mmap.c) and does not change any kernel code.",
  "WorthFuzzing": false
}

Results: 
{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies a selftest tool (tools/testing/selftests/net/tcp_mmap.c) and does not change any kernel code.",
  "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)