AI Trajectory


Trajectory: (Expand/Collapse All)
Seq Timestamp Type Name Duration
0/0 2026/08/12 20:42 flow patch-triage
0m Args:
null

Results:
{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "KMSANReasoning": "",
  "NeedsKMSAN": false,
  "Reasoning": "The patch removes the CONFIG_DEBUG_FORCE_WEAK_PER_CPU configuration option and its associated logic from Kconfig and header files. It does not introduce any new functional logic or alter execution flow in a way that requires fuzzing.",
  "WorthFuzzing": false
}

1/1 2026/08/12 20:42 action read-patch-diff
0m Args:
null

Results:
{
  "PatchDiff": "commit 9d38b98f01c24922816b571588f3e9132e6365db\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Wed Aug 12 20:41:59 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h\nindex 43c854a273c3a..0be4d0f23f1d0 100644\n--- a/include/linux/percpu-defs.h\n+++ b/include/linux/percpu-defs.h\n@@ -65,13 +65,8 @@\n  *\n  * Archs which need weak percpu definitions should set\n  * CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU when necessary.\n- *\n- * To ensure that the generic code observes the above two\n- * restrictions, if CONFIG_DEBUG_FORCE_WEAK_PER_CPU is set weak\n- * definition is used for all cases.\n  */\n-#if (defined(CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU) \u0026\u0026 defined(MODULE)) || \\\n-\tdefined(CONFIG_DEBUG_FORCE_WEAK_PER_CPU)\n+#if defined(CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU) \u0026\u0026 defined(MODULE)\n /*\n  * __pcpu_scope_* dummy variable is used to enforce scope.  It\n  * receives the static modifier when it's used in front of\ndiff --git a/include/rv/da_monitor.h b/include/rv/da_monitor.h\nindex 34b8fba9ecd44..6b641697106bf 100644\n--- a/include/rv/da_monitor.h\n+++ b/include/rv/da_monitor.h\n@@ -24,7 +24,7 @@\n \n /*\n  * Per-cpu variables require a unique name although static in some\n- * configurations (e.g. CONFIG_DEBUG_FORCE_WEAK_PER_CPU or alpha modules).\n+ * configurations (e.g. alpha modules).\n  */\n #define DA_MON_NAME CONCATENATE(da_mon_, MONITOR_NAME)\n \ndiff --git a/lib/Kconfig.debug b/lib/Kconfig.debug\nindex 1244dcac2294a..26c8b19d07958 100644\n--- a/lib/Kconfig.debug\n+++ b/lib/Kconfig.debug\n@@ -613,21 +613,6 @@ config BUILTIN_MODULE_RANGES\n \t It also records an anchor symbol to determine the load address of the\n \t section.\n \n-config DEBUG_FORCE_WEAK_PER_CPU\n-\tbool \"Force weak per-cpu definitions\"\n-\tdepends on DEBUG_KERNEL\n-\thelp\n-\t  s390 and alpha require percpu variables in modules to be\n-\t  defined weak to work around addressing range issue which\n-\t  puts the following two restrictions on percpu variable\n-\t  definitions.\n-\n-\t  1. percpu symbols must be unique whether static or not\n-\t  2. percpu variables can't be defined inside a function\n-\n-\t  To ensure that generic code follows the above rules, this\n-\t  option forces all percpu variables to be defined as weak.\n-\n config WARN_CONTEXT_ANALYSIS\n \tbool \"Compiler context-analysis warnings\"\n \tdepends on CC_IS_CLANG \u0026\u0026 CLANG_VERSION \u003e= 230000\n@@ -1053,7 +1038,6 @@ config MEM_ALLOC_PROFILING\n \tdefault n\n \tdepends on MMU\n \tdepends on PROC_FS\n-\tdepends on !DEBUG_FORCE_WEAK_PER_CPU\n \tselect CODE_TAGGING\n \tselect PAGE_EXTENSION\n \tselect SLAB_OBJ_EXT\n"
}

2/1 2026/08/12 20:42 agent patch-evaluator
0m Model:
best-expensive

Args:
null

Results:
{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch removes the CONFIG_DEBUG_FORCE_WEAK_PER_CPU configuration option and its associated logic from Kconfig and header files. It does not introduce any new functional logic or alter execution flow in a way that requires fuzzing.",
  "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).
- Code in vendor-specific PCIe switch, SmartNIC, or GPU drivers (e.g., mlxsw, pds_core, qed,
  ionic, amdgpu) that require physical PCIe hardware cards not emulated in standard QEMU.
- Driver .remove, .shutdown, or pci_unregister_driver teardown callbacks (e.g., igb_remove)
  that are executed only during PCI hot-unplug or sysfs driver unbind operations.

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.
   Prefer non-static, non-inlined API entrypoint functions over internal static helper functions
   (which are inlined by the compiler and do not have distinct symbol addresses).
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.
   Also check "depends on" lines in Kconfig to include any non-standard parent subsystem configs
   needed for Kbuild to compile the code statically into vmlinux. 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 9d38b98f01c24922816b571588f3e9132e6365db
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Aug 12 20:41:59 2026 +0000

    syz-cluster: applied patch under review

diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index 43c854a273c3a..0be4d0f23f1d0 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -65,13 +65,8 @@
  *
  * Archs which need weak percpu definitions should set
  * CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU when necessary.
- *
- * To ensure that the generic code observes the above two
- * restrictions, if CONFIG_DEBUG_FORCE_WEAK_PER_CPU is set weak
- * definition is used for all cases.
  */
-#if (defined(CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU) && defined(MODULE)) || \
-	defined(CONFIG_DEBUG_FORCE_WEAK_PER_CPU)
+#if defined(CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU) && defined(MODULE)
 /*
  * __pcpu_scope_* dummy variable is used to enforce scope.  It
  * receives the static modifier when it's used in front of
diff --git a/include/rv/da_monitor.h b/include/rv/da_monitor.h
index 34b8fba9ecd44..6b641697106bf 100644
--- a/include/rv/da_monitor.h
+++ b/include/rv/da_monitor.h
@@ -24,7 +24,7 @@
 
 /*
  * Per-cpu variables require a unique name although static in some
- * configurations (e.g. CONFIG_DEBUG_FORCE_WEAK_PER_CPU or alpha modules).
+ * configurations (e.g. alpha modules).
  */
 #define DA_MON_NAME CONCATENATE(da_mon_, MONITOR_NAME)
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1244dcac2294a..26c8b19d07958 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -613,21 +613,6 @@ config BUILTIN_MODULE_RANGES
 	 It also records an anchor symbol to determine the load address of the
 	 section.
 
-config DEBUG_FORCE_WEAK_PER_CPU
-	bool "Force weak per-cpu definitions"
-	depends on DEBUG_KERNEL
-	help
-	  s390 and alpha require percpu variables in modules to be
-	  defined weak to work around addressing range issue which
-	  puts the following two restrictions on percpu variable
-	  definitions.
-
-	  1. percpu symbols must be unique whether static or not
-	  2. percpu variables can't be defined inside a function
-
-	  To ensure that generic code follows the above rules, this
-	  option forces all percpu variables to be defined as weak.
-
 config WARN_CONTEXT_ANALYSIS
 	bool "Compiler context-analysis warnings"
 	depends on CC_IS_CLANG && CLANG_VERSION >= 230000
@@ -1053,7 +1038,6 @@ config MEM_ALLOC_PROFILING
 	default n
 	depends on MMU
 	depends on PROC_FS
-	depends on !DEBUG_FORCE_WEAK_PER_CPU
 	select CODE_TAGGING
 	select PAGE_EXTENSION
 	select SLAB_OBJ_EXT

3/2 2026/08/12 20:42 llm patch-evaluator
0m Model:
gemini-3.1-pro-preview

Args:
null

Results:
null

Tokens:
							input: 2676
							output: 80
							thoughts: 372
						

Thoughts:
**My Assessment of the Configuration Cleanup**

Okay, so this patch is pretty straightforward. It looks like a cleanup operation, specifically targeting the removal of the `CONFIG_DEBUG_FORCE_WEAK_PER_CPU` debug configuration option. My immediate impression is that this *shouldn't* introduce any functional regressions or necessitate any fuzzing efforts. Let's dig in and confirm that, though.

First, it’s yanked from a few spots: `include/linux/percpu-defs.h`, `include/rv/da_monitor.h`, and `lib/Kconfig.debug`. I need to ensure that the removal is clean and doesn't leave any dangling dependencies or introduce semantic changes.

Looking at `include/linux/percpu-defs.h`, the change is clear: it’s just removing the `#if defined(CONFIG_DEBUG_FORCE_WEAK_PER_CPU)` condition from a macro definition. No code is being added, just a conditional branch being removed. This aligns with a pure cleanup.

`include/rv/da_monitor.h` is just a comment change so nothing significant there.

Finally, in `lib/Kconfig.debug`, it's dropping the debug option itself and removing the `depends on !DEBUG_FORCE_WEAK_PER_CPU` dependency from `MEM_ALLOC_PROFILING`. This is precisely what the description states - a clean removal of the debugging feature and any constraints it imposed.

Given this analysis, I'm confident that this patch is solely a removal of a debugging configuration option and its associated logic. It doesn't modify execution flow, add new functional code, or change any core behavior. Therefore, this patch is **not worth fuzzing.**



4/2 2026/08/12 20:42 tool set-results
0m Args:
{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch removes the CONFIG_DEBUG_FORCE_WEAK_PER_CPU configuration option and its associated logic from Kconfig and header files. It does not introduce any new functional logic or alter execution flow in a way that requires fuzzing.",
  "WorthFuzzing": false
}

Results:
{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch removes the CONFIG_DEBUG_FORCE_WEAK_PER_CPU configuration option and its associated logic from Kconfig and header files. It does not introduce any new functional logic or alter execution flow in a way that requires fuzzing.",
  "WorthFuzzing": false
}

5/1 2026/08/12 20:42 action If
0m Args:
{
  "WorthFuzzing": false
}

Results:
null

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)