AI Trajectory

Trajectory: (Expand/Collapse All)
Seq	Timestamp	Type	Name	Duration
0/0	2026/07/28 05:53	flow	patch-triage	0m Args: null Results: { "EnableConfigs": null, "FocusSymbols": [], "Reasoning": "The patch only contains modifications to Kconfig files, code comments, and selftests. It does not modify any executable kernel source code.", "WorthFuzzing": false }
1/1	2026/07/28 05:53	action	read-patch-diff	0m Args: null Results: { "PatchDiff": "commit 62a3a8121a04e0092593e65a5e4a10df36ceccdf\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Tue Jul 28 05:53:18 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig\nindex 0de419ed780f13..c98dca76859b11 100644\n--- a/arch/arm64/Kconfig\n+++ b/arch/arm64/Kconfig\n@@ -188,6 +188,8 @@ config ARM64\n \t\t CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)\n \tselect HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \\\n \t\tif DYNAMIC_FTRACE_WITH_ARGS\n+\tselect HAVE_SINGLE_FTRACE_DIRECT_OPS \\\n+\t\tif DYNAMIC_FTRACE_WITH_DIRECT_CALLS\n \tselect HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \\\n \t\tif (DYNAMIC_FTRACE_WITH_ARGS \u0026\u0026 !CFI \u0026\u0026 \\\n \t\t (CC_IS_CLANG \|\| !CC_OPTIMIZE_FOR_SIZE))\ndiff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c\nindex e1a3c0b3a05146..56ba72a87dfac0 100644\n--- a/arch/arm64/kernel/ftrace.c\n+++ b/arch/arm64/kernel/ftrace.c\n@@ -301,8 +301,7 @@ static bool ftrace_find_callable_addr(struct dyn_ftrace rec,\n \n \t/\n \t * If a custom trampoline is unreachable, rely on the ftrace_caller\n-\t * trampoline which knows how to indirectly reach that trampoline\n-\t * through ops-\u003edirect_call.\n+\t * trampoline which knows how to indirectly reach that trampoline.\n \t /\n \tif (addr != FTRACE_ADDR \u0026\u0026 !reachable_by_bl(addr, pc))\n \t\taddr = FTRACE_ADDR;\ndiff --git a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c\nindex f02ffc7f41d784..5aa48e09034044 100644\n--- a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c\n+++ b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c\n@@ -612,7 +612,7 @@ void serial_test_tracing_multi_bench_attach(void)\n \tstruct btf btf;\n \tint err;\n \n-#ifndef __x86_64__\n+#if !ARCH_SUPPORTS_TRACING_MULTI_LINK\n \ttest__skip();\n \treturn;\n #endif\n@@ -923,6 +923,11 @@ static void test_rollback_unlink(void)\n \n void serial_test_tracing_multi_attach_rollback(void)\n {\n+#if !ARCH_SUPPORTS_TRACING_MULTI_LINK\n+\ttest__skip();\n+\treturn;\n+#endif\n+\n \tif (test__start_subtest(\"put\"))\n \t\ttest_rollback_put();\n \tif (test__start_subtest(\"unlink\"))\n@@ -931,7 +936,7 @@ void serial_test_tracing_multi_attach_rollback(void)\n \n void test_tracing_multi_test(void)\n {\n-#ifndef __x86_64__\n+#if !ARCH_SUPPORTS_TRACING_MULTI_LINK\n \ttest__skip();\n \treturn;\n #endif\ndiff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h\nindex 2cf950afcd8543..b1498e84773c84 100644\n--- a/tools/testing/selftests/bpf/test_progs.h\n+++ b/tools/testing/selftests/bpf/test_progs.h\n@@ -567,4 +567,10 @@ void validate_msgs(const char log_buf, struct expected_msgs msgs,\n void free_msgs(struct expected_msgs msgs);\n void verify_test_stderr(struct bpf_object obj, struct bpf_program prog);\n \n+#if defined(__x86_64__) \|\| defined(__aarch64__)\n+#define ARCH_SUPPORTS_TRACING_MULTI_LINK 1\n+#else\n+#define ARCH_SUPPORTS_TRACING_MULTI_LINK 0\n+#endif\n+\n #endif /* __TEST_PROGS_H */\n" }
2/1	2026/07/28 05:53	agent	patch-evaluator	0m Model: best-expensive Args: null Results: { "EnableConfigs": null, "FocusSymbols": [], "Reasoning": "The patch only contains modifications to Kconfig files, code comments, and selftests. It does not modify any executable kernel source 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). - 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 62a3a8121a04e0092593e65a5e4a10df36ceccdf Author: syz-cluster <triage@syzkaller.com> Date: Tue Jul 28 05:53:18 2026 +0000 syz-cluster: applied patch under review diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 0de419ed780f13..c98dca76859b11 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -188,6 +188,8 @@ config ARM64 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ if DYNAMIC_FTRACE_WITH_ARGS + select HAVE_SINGLE_FTRACE_DIRECT_OPS \ + if DYNAMIC_FTRACE_WITH_DIRECT_CALLS select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \ (CC_IS_CLANG \|\| !CC_OPTIMIZE_FOR_SIZE)) diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index e1a3c0b3a05146..56ba72a87dfac0 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -301,8 +301,7 @@ static bool ftrace_find_callable_addr(struct dyn_ftrace rec, / * If a custom trampoline is unreachable, rely on the ftrace_caller - * trampoline which knows how to indirectly reach that trampoline - * through ops->direct_call. + * trampoline which knows how to indirectly reach that trampoline. / if (addr != FTRACE_ADDR && !reachable_by_bl(addr, pc)) addr = FTRACE_ADDR; diff --git a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c index f02ffc7f41d784..5aa48e09034044 100644 --- a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c +++ b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c @@ -612,7 +612,7 @@ void serial_test_tracing_multi_bench_attach(void) struct btf btf; int err; -#ifndef __x86_64__ +#if !ARCH_SUPPORTS_TRACING_MULTI_LINK test__skip(); return; #endif @@ -923,6 +923,11 @@ static void test_rollback_unlink(void) void serial_test_tracing_multi_attach_rollback(void) { +#if !ARCH_SUPPORTS_TRACING_MULTI_LINK + test__skip(); + return; +#endif + if (test__start_subtest("put")) test_rollback_put(); if (test__start_subtest("unlink")) @@ -931,7 +936,7 @@ void serial_test_tracing_multi_attach_rollback(void) void test_tracing_multi_test(void) { -#ifndef __x86_64__ +#if !ARCH_SUPPORTS_TRACING_MULTI_LINK test__skip(); return; #endif diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h index 2cf950afcd8543..b1498e84773c84 100644 --- a/tools/testing/selftests/bpf/test_progs.h +++ b/tools/testing/selftests/bpf/test_progs.h @@ -567,4 +567,10 @@ void validate_msgs(const char log_buf, struct expected_msgs msgs, void free_msgs(struct expected_msgs msgs); void verify_test_stderr(struct bpf_object obj, struct bpf_program prog); +#if defined(__x86_64__) \|\| defined(__aarch64__) +#define ARCH_SUPPORTS_TRACING_MULTI_LINK 1 +#else +#define ARCH_SUPPORTS_TRACING_MULTI_LINK 0 +#endif + #endif /* __TEST_PROGS_H */
3/2	2026/07/28 05:53	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 3004 output: 25 thoughts: 325 Thoughts: Analyzing a Patch: Minimal Functional Impact? Okay, so I'm looking at this patch and it touches a few files: `arch/arm64/Kconfig`, `arch/arm64/kernel/ftrace.c`, and some BPF selftests. Initially, it seems pretty straightforward. The `Kconfig` change looks like it's selecting `HAVE_SINGLE_FTRACE_DIRECT_OPS` if `DYNAMIC_FTRACE_WITH_DIRECT_CALLS` is enabled. Seems like a dependency or configuration flag related to ftrace and direct calls. Then, `arch/arm64/kernel/ftrace.c` is just a comment tweak, which is usually not a big deal. The BPF selftest changes in `tracing_multi.c` and `test_progs.h` update architecture checks, likely to account for the new configuration. But wait, is this just configuration and testing, or is there any actual kernel functionality being modified? It's important to be careful, even with seemingly innocuous changes. Let's break it down again to make sure: the Kconfig change adds a `select` statement. The ftrace.c change is just a comment. And the BPF files are definitely selftests. Okay, I'm getting a little uneasy about that `select HAVE_SINGLE_FTRACE_DIRECT_OPS` statement in the `Kconfig` file. Even though the other changes are clearly not functional, that select might enable some code paths within the kernel itself. I can't be sure until I know what `HAVE_SINGLE_FTRACE_DIRECT_OPS` actually does. I need to investigate that Kconfig option and see what it enables. That's the key to understanding the full impact here.
4/2	2026/07/28 05:53	tool	grepper	0m Args: { "Expression": "HAVE_SINGLE_FTRACE_DIRECT_OPS" } Results: { "Output": "arch/arm64/Kconfig=2=config ARM64\n--\narch/arm64/Kconfig-190-\t\tif DYNAMIC_FTRACE_WITH_ARGS\narch/arm64/Kconfig:191:\tselect HAVE_SINGLE_FTRACE_DIRECT_OPS \\\narch/arm64/Kconfig-192-\t\tif DYNAMIC_FTRACE_WITH_DIRECT_CALLS\n--\narch/x86/Kconfig=58=config X86\n--\narch/x86/Kconfig-337-\tselect ARCH_SUPPORTS_SCHED_MC\t\tif SMP\narch/x86/Kconfig:338:\tselect HAVE_SINGLE_FTRACE_DIRECT_OPS\tif X86_64 \u0026\u0026 DYNAMIC_FTRACE_WITH_DIRECT_CALLS\narch/x86/Kconfig-339-\n--\nkernel/bpf/trampoline.c=72=static const struct bpf_trampoline_ops trampoline_ops;\nkernel/bpf/trampoline.c-73-\nkernel/bpf/trampoline.c:74:#ifdef CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS\nkernel/bpf/trampoline.c-75-static struct bpf_trampoline direct_ops_ip_lookup(struct ftrace_ops ops, unsigned long ip)\n--\nkernel/bpf/trampoline.c=92=static struct bpf_trampoline direct_ops_ip_lookup(struct ftrace_ops ops, unsigned long ip)\n--\nkernel/bpf/trampoline.c-95-}\nkernel/bpf/trampoline.c:96:#endif /* CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS /\nkernel/bpf/trampoline.c-97-\n--\nkernel/bpf/trampoline.c=210=void bpf_image_ksym_del(struct bpf_ksym ksym)\n--\nkernel/bpf/trampoline.c-217-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS\nkernel/bpf/trampoline.c:218:#ifdef CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS\nkernel/bpf/trampoline.c-219-/\n--\nkernel/bpf/trampoline.c=337=static int direct_ops_mod(struct bpf_trampoline tr, void ptr, bool lock_direct_mutex)\n--\nkernel/bpf/trampoline.c-347-}\nkernel/bpf/trampoline.c:348:#endif / CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS /\nkernel/bpf/trampoline.c-349-#else\n--\nkernel/bpf/trampoline.c=1467=int __weak arch_bpf_trampoline_size(const struct btf_func_model m, u32 flags,\n--\nkernel/bpf/trampoline.c-1473-#if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) \u0026\u0026 \\\nkernel/bpf/trampoline.c:1474: defined(CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS) \u0026\u0026 \\\nkernel/bpf/trampoline.c-1475- defined(CONFIG_BPF_SYSCALL)\n--\nkernel/bpf/trampoline.c=1711=int bpf_trampoline_multi_detach(struct bpf_prog prog, struct bpf_tracing_multi_link link)\n--\nkernel/bpf/trampoline.c-1746-#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \u0026\u0026\nkernel/bpf/trampoline.c:1747:\t CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS \u0026\u0026\nkernel/bpf/trampoline.c-1748-\t CONFIG_BPF_SYSCALL /\n--\nkernel/trace/Kconfig=50=config HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS\n--\nkernel/trace/Kconfig-52-\nkernel/trace/Kconfig:53:config HAVE_SINGLE_FTRACE_DIRECT_OPS\nkernel/trace/Kconfig-54-\tbool\n--\nkernel/trace/bpf_trace.c=3680=__bpf_kfunc_end_defs();\n--\nkernel/trace/bpf_trace.c-3682-#if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) \u0026\u0026 \\\nkernel/trace/bpf_trace.c:3683: defined(CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS)\nkernel/trace/bpf_trace.c-3684-\n--\nkernel/trace/bpf_trace.c=3875=int bpf_tracing_multi_attach(struct bpf_prog prog, const union bpf_attr attr)\n--\nkernel/trace/bpf_trace.c-3879-\nkernel/trace/bpf_trace.c:3880:#endif / CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \u0026\u0026 CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS */\n--\nkernel/trace/ftrace.c=2649=static void call_direct_funcs(unsigned long ip, unsigned long pip,\n--\nkernel/trace/ftrace.c-2653-\nkernel/trace/ftrace.c:2654:#ifdef CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS\nkernel/trace/ftrace.c-2655-\taddr = ftrace_find_rec_direct(ip);\n" }
5/2	2026/07/28 05:53	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 5100 output: 59 thoughts: 867 Thoughts: WorthFuzzing Decision for the Patch Okay, let me break this down. This patch is enabling `CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS` on ARM64. That, in turn, enables some functionality in `kernel/bpf/trampoline.c`, `kernel/trace/bpf_trace.c`, and `kernel/trace/ftrace.c`. But hold on, the patch itself is only touching Kconfig, selftests, and a comment. It's enabling a feature (BPF multi-attach) on ARM64, but not actually modifying any C code directly, only activating existing code. The instructions say to return `WorthFuzzing=false` if the patch only contains modifications to documentation, Kconfig files, or code comments. And, I see that this patch's diff includes only: `arch/arm64/Kconfig`, which is a Kconfig file; `arch/arm64/kernel/ftrace.c`, which has a comment; and some selftests, specifically `tools/testing/selftests/bpf/prog_tests/tracing_multi.c` and `tools/testing/selftests/bpf/test_progs.h`. The rule is very clear: "Return WorthFuzzing=false if the patch only contains: - Modifications to Documentation/, Kconfig files, or code comments." This patch exactly fits that description. It's purely Kconfig, comments, and selftests. Now, I'm used to thinking about whether new features should be fuzzed, especially when they're enabled via Kconfig. Syzkaller usually works based on code coverage, so a new feature could be fuzz-worthy. But the prompt explicitly gives a rule, and I'm obligated to follow it. Okay, let's re-read the diff again to be absolutely sure. Nope, it's just Kconfig, comment, and selftests. The selftests are not kernel code and are user-space. Therefore, because this patch only contains changes to Kconfig files, code comments, and selftests, it directly matches the criteria in the prompt. I will return `WorthFuzzing=false`.
6/2	2026/07/28 05:53	tool	set-results	0m Args: { "EnableConfigs": [], "FocusSymbols": [], "Reasoning": "The patch only contains modifications to Kconfig files, code comments, and selftests. It does not modify any executable kernel source code.", "WorthFuzzing": false } Results: { "EnableConfigs": null, "FocusSymbols": [], "Reasoning": "The patch only contains modifications to Kconfig files, code comments, and selftests. It does not modify any executable kernel source code.", "WorthFuzzing": false }

Trajectory: (Expand/Collapse All)

Seq

Timestamp

Type

Name

Duration

0/0

2026/07/28 05:53

flow

patch-triage

Args:

null

Results:

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only contains modifications to Kconfig files, code comments, and selftests. It does not modify any executable kernel source code.",
  "WorthFuzzing": false
}

1/1

2026/07/28 05:53

action

read-patch-diff

Args:

null

Results:

{
  "PatchDiff": "commit 62a3a8121a04e0092593e65a5e4a10df36ceccdf\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Tue Jul 28 05:53:18 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig\nindex 0de419ed780f13..c98dca76859b11 100644\n--- a/arch/arm64/Kconfig\n+++ b/arch/arm64/Kconfig\n@@ -188,6 +188,8 @@ config ARM64\n \t\t    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)\n \tselect HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \\\n \t\tif DYNAMIC_FTRACE_WITH_ARGS\n+\tselect HAVE_SINGLE_FTRACE_DIRECT_OPS \\\n+\t\tif DYNAMIC_FTRACE_WITH_DIRECT_CALLS\n \tselect HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \\\n \t\tif (DYNAMIC_FTRACE_WITH_ARGS \u0026\u0026 !CFI \u0026\u0026 \\\n \t\t    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))\ndiff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c\nindex e1a3c0b3a05146..56ba72a87dfac0 100644\n--- a/arch/arm64/kernel/ftrace.c\n+++ b/arch/arm64/kernel/ftrace.c\n@@ -301,8 +301,7 @@ static bool ftrace_find_callable_addr(struct dyn_ftrace *rec,\n \n \t/*\n \t * If a custom trampoline is unreachable, rely on the ftrace_caller\n-\t * trampoline which knows how to indirectly reach that trampoline\n-\t * through ops-\u003edirect_call.\n+\t * trampoline which knows how to indirectly reach that trampoline.\n \t */\n \tif (*addr != FTRACE_ADDR \u0026\u0026 !reachable_by_bl(*addr, pc))\n \t\t*addr = FTRACE_ADDR;\ndiff --git a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c\nindex f02ffc7f41d784..5aa48e09034044 100644\n--- a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c\n+++ b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c\n@@ -612,7 +612,7 @@ void serial_test_tracing_multi_bench_attach(void)\n \tstruct btf *btf;\n \tint err;\n \n-#ifndef __x86_64__\n+#if !ARCH_SUPPORTS_TRACING_MULTI_LINK\n \ttest__skip();\n \treturn;\n #endif\n@@ -923,6 +923,11 @@ static void test_rollback_unlink(void)\n \n void serial_test_tracing_multi_attach_rollback(void)\n {\n+#if !ARCH_SUPPORTS_TRACING_MULTI_LINK\n+\ttest__skip();\n+\treturn;\n+#endif\n+\n \tif (test__start_subtest(\"put\"))\n \t\ttest_rollback_put();\n \tif (test__start_subtest(\"unlink\"))\n@@ -931,7 +936,7 @@ void serial_test_tracing_multi_attach_rollback(void)\n \n void test_tracing_multi_test(void)\n {\n-#ifndef __x86_64__\n+#if !ARCH_SUPPORTS_TRACING_MULTI_LINK\n \ttest__skip();\n \treturn;\n #endif\ndiff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h\nindex 2cf950afcd8543..b1498e84773c84 100644\n--- a/tools/testing/selftests/bpf/test_progs.h\n+++ b/tools/testing/selftests/bpf/test_progs.h\n@@ -567,4 +567,10 @@ void validate_msgs(const char *log_buf, struct expected_msgs *msgs,\n void free_msgs(struct expected_msgs *msgs);\n void verify_test_stderr(struct bpf_object *obj, struct bpf_program *prog);\n \n+#if defined(__x86_64__) || defined(__aarch64__)\n+#define ARCH_SUPPORTS_TRACING_MULTI_LINK 1\n+#else\n+#define ARCH_SUPPORTS_TRACING_MULTI_LINK 0\n+#endif\n+\n #endif /* __TEST_PROGS_H */\n"
}

2/1

2026/07/28 05:53

agent

patch-evaluator

Model:

best-expensive

Args:

null

Results:

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only contains modifications to Kconfig files, code comments, and selftests. It does not modify any executable kernel source 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).
- 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 62a3a8121a04e0092593e65a5e4a10df36ceccdf
Author: syz-cluster <triage@syzkaller.com>
Date:   Tue Jul 28 05:53:18 2026 +0000

    syz-cluster: applied patch under review

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 0de419ed780f13..c98dca76859b11 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -188,6 +188,8 @@ config ARM64
 		    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
 	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
 		if DYNAMIC_FTRACE_WITH_ARGS
+	select HAVE_SINGLE_FTRACE_DIRECT_OPS \
+		if DYNAMIC_FTRACE_WITH_DIRECT_CALLS
 	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
 		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \
 		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
index e1a3c0b3a05146..56ba72a87dfac0 100644
--- a/arch/arm64/kernel/ftrace.c
+++ b/arch/arm64/kernel/ftrace.c
@@ -301,8 +301,7 @@ static bool ftrace_find_callable_addr(struct dyn_ftrace *rec,
 
 	/*
 	 * If a custom trampoline is unreachable, rely on the ftrace_caller
-	 * trampoline which knows how to indirectly reach that trampoline
-	 * through ops->direct_call.
+	 * trampoline which knows how to indirectly reach that trampoline.
 	 */
 	if (*addr != FTRACE_ADDR && !reachable_by_bl(*addr, pc))
 		*addr = FTRACE_ADDR;
diff --git a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
index f02ffc7f41d784..5aa48e09034044 100644
--- a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
+++ b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
@@ -612,7 +612,7 @@ void serial_test_tracing_multi_bench_attach(void)
 	struct btf *btf;
 	int err;
 
-#ifndef __x86_64__
+#if !ARCH_SUPPORTS_TRACING_MULTI_LINK
 	test__skip();
 	return;
 #endif
@@ -923,6 +923,11 @@ static void test_rollback_unlink(void)
 
 void serial_test_tracing_multi_attach_rollback(void)
 {
+#if !ARCH_SUPPORTS_TRACING_MULTI_LINK
+	test__skip();
+	return;
+#endif
+
 	if (test__start_subtest("put"))
 		test_rollback_put();
 	if (test__start_subtest("unlink"))
@@ -931,7 +936,7 @@ void serial_test_tracing_multi_attach_rollback(void)
 
 void test_tracing_multi_test(void)
 {
-#ifndef __x86_64__
+#if !ARCH_SUPPORTS_TRACING_MULTI_LINK
 	test__skip();
 	return;
 #endif
diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index 2cf950afcd8543..b1498e84773c84 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -567,4 +567,10 @@ void validate_msgs(const char *log_buf, struct expected_msgs *msgs,
 void free_msgs(struct expected_msgs *msgs);
 void verify_test_stderr(struct bpf_object *obj, struct bpf_program *prog);
 
+#if defined(__x86_64__) || defined(__aarch64__)
+#define ARCH_SUPPORTS_TRACING_MULTI_LINK 1
+#else
+#define ARCH_SUPPORTS_TRACING_MULTI_LINK 0
+#endif
+
 #endif /* __TEST_PROGS_H */

3/2

2026/07/28 05:53

llm

patch-evaluator

Model:

gemini-3.1-pro-preview

Args:

null

Results:

null

Tokens:

							input: 3004
							output: 25
							thoughts: 325

Thoughts:

**Analyzing a Patch: Minimal Functional Impact?**

Okay, so I'm looking at this patch and it touches a few files: `arch/arm64/Kconfig`, `arch/arm64/kernel/ftrace.c`, and some BPF selftests. Initially, it seems pretty straightforward. The `Kconfig` change looks like it's selecting `HAVE_SINGLE_FTRACE_DIRECT_OPS` if `DYNAMIC_FTRACE_WITH_DIRECT_CALLS` is enabled. Seems like a dependency or configuration flag related to ftrace and direct calls. Then, `arch/arm64/kernel/ftrace.c` is just a comment tweak, which is usually not a big deal. The BPF selftest changes in `tracing_multi.c` and `test_progs.h` update architecture checks, likely to account for the new configuration.

But wait, is this *just* configuration and testing, or is there any actual kernel functionality being modified? It's important to be careful, even with seemingly innocuous changes. Let's break it down again to make sure: the Kconfig change adds a `select` statement. The ftrace.c change is just a comment. And the BPF files are definitely selftests.

Okay, I'm getting a little uneasy about that `select HAVE_SINGLE_FTRACE_DIRECT_OPS` statement in the `Kconfig` file. Even though the other changes are clearly not functional, that select might *enable* some code paths within the kernel itself. I can't be sure until I know what `HAVE_SINGLE_FTRACE_DIRECT_OPS` actually *does*. I need to investigate that Kconfig option and see what it enables. That's the key to understanding the full impact here.

4/2

2026/07/28 05:53

tool

grepper

Args:

{
  "Expression": "HAVE_SINGLE_FTRACE_DIRECT_OPS"
}

Results:

{
  "Output": "arch/arm64/Kconfig=2=config ARM64\n--\narch/arm64/Kconfig-190-\t\tif DYNAMIC_FTRACE_WITH_ARGS\narch/arm64/Kconfig:191:\tselect HAVE_SINGLE_FTRACE_DIRECT_OPS \\\narch/arm64/Kconfig-192-\t\tif DYNAMIC_FTRACE_WITH_DIRECT_CALLS\n--\narch/x86/Kconfig=58=config X86\n--\narch/x86/Kconfig-337-\tselect ARCH_SUPPORTS_SCHED_MC\t\tif SMP\narch/x86/Kconfig:338:\tselect HAVE_SINGLE_FTRACE_DIRECT_OPS\tif X86_64 \u0026\u0026 DYNAMIC_FTRACE_WITH_DIRECT_CALLS\narch/x86/Kconfig-339-\n--\nkernel/bpf/trampoline.c=72=static const struct bpf_trampoline_ops trampoline_ops;\nkernel/bpf/trampoline.c-73-\nkernel/bpf/trampoline.c:74:#ifdef CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS\nkernel/bpf/trampoline.c-75-static struct bpf_trampoline *direct_ops_ip_lookup(struct ftrace_ops *ops, unsigned long ip)\n--\nkernel/bpf/trampoline.c=92=static struct bpf_trampoline *direct_ops_ip_lookup(struct ftrace_ops *ops, unsigned long ip)\n--\nkernel/bpf/trampoline.c-95-}\nkernel/bpf/trampoline.c:96:#endif /* CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS */\nkernel/bpf/trampoline.c-97-\n--\nkernel/bpf/trampoline.c=210=void bpf_image_ksym_del(struct bpf_ksym *ksym)\n--\nkernel/bpf/trampoline.c-217-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS\nkernel/bpf/trampoline.c:218:#ifdef CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS\nkernel/bpf/trampoline.c-219-/*\n--\nkernel/bpf/trampoline.c=337=static int direct_ops_mod(struct bpf_trampoline *tr, void *ptr, bool lock_direct_mutex)\n--\nkernel/bpf/trampoline.c-347-}\nkernel/bpf/trampoline.c:348:#endif /* CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS */\nkernel/bpf/trampoline.c-349-#else\n--\nkernel/bpf/trampoline.c=1467=int __weak arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,\n--\nkernel/bpf/trampoline.c-1473-#if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) \u0026\u0026 \\\nkernel/bpf/trampoline.c:1474:    defined(CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS) \u0026\u0026 \\\nkernel/bpf/trampoline.c-1475-    defined(CONFIG_BPF_SYSCALL)\n--\nkernel/bpf/trampoline.c=1711=int bpf_trampoline_multi_detach(struct bpf_prog *prog, struct bpf_tracing_multi_link *link)\n--\nkernel/bpf/trampoline.c-1746-#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \u0026\u0026\nkernel/bpf/trampoline.c:1747:\t  CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS \u0026\u0026\nkernel/bpf/trampoline.c-1748-\t  CONFIG_BPF_SYSCALL */\n--\nkernel/trace/Kconfig=50=config HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS\n--\nkernel/trace/Kconfig-52-\nkernel/trace/Kconfig:53:config HAVE_SINGLE_FTRACE_DIRECT_OPS\nkernel/trace/Kconfig-54-\tbool\n--\nkernel/trace/bpf_trace.c=3680=__bpf_kfunc_end_defs();\n--\nkernel/trace/bpf_trace.c-3682-#if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) \u0026\u0026 \\\nkernel/trace/bpf_trace.c:3683:    defined(CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS)\nkernel/trace/bpf_trace.c-3684-\n--\nkernel/trace/bpf_trace.c=3875=int bpf_tracing_multi_attach(struct bpf_prog *prog, const union bpf_attr *attr)\n--\nkernel/trace/bpf_trace.c-3879-\nkernel/trace/bpf_trace.c:3880:#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \u0026\u0026 CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS */\n--\nkernel/trace/ftrace.c=2649=static void call_direct_funcs(unsigned long ip, unsigned long pip,\n--\nkernel/trace/ftrace.c-2653-\nkernel/trace/ftrace.c:2654:#ifdef CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS\nkernel/trace/ftrace.c-2655-\taddr = ftrace_find_rec_direct(ip);\n"
}

5/2

2026/07/28 05:53

llm

patch-evaluator

Model:

gemini-3.1-pro-preview

Args:

null

Results:

null

Tokens:

							input: 5100
							output: 59
							thoughts: 867

Thoughts:

**WorthFuzzing Decision for the Patch**

Okay, let me break this down. This patch is enabling `CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS` on ARM64. That, in turn, enables some functionality in `kernel/bpf/trampoline.c`, `kernel/trace/bpf_trace.c`, and `kernel/trace/ftrace.c`. But hold on, the patch *itself* is only touching Kconfig, selftests, and a comment. It's enabling a feature (BPF multi-attach) on ARM64, but not actually *modifying* any C code directly, only activating existing code.

The instructions say to return `WorthFuzzing=false` if the patch *only* contains modifications to documentation, Kconfig files, or code comments. And, I see that this patch's diff includes only: `arch/arm64/Kconfig`, which is a Kconfig file; `arch/arm64/kernel/ftrace.c`, which has a comment; and some selftests, specifically `tools/testing/selftests/bpf/prog_tests/tracing_multi.c` and `tools/testing/selftests/bpf/test_progs.h`.

The rule is very clear: "Return WorthFuzzing=false if the patch only contains: - Modifications to Documentation/, Kconfig files, or code comments." This patch *exactly* fits that description. It's purely Kconfig, comments, and selftests.

Now, I'm used to thinking about whether new features should be fuzzed, especially when they're enabled via Kconfig. Syzkaller usually works based on code coverage, so a new feature *could* be fuzz-worthy. But the prompt explicitly gives a rule, and I'm obligated to follow it.

Okay, let's re-read the diff again to be absolutely sure. Nope, it's just Kconfig, comment, and selftests. The selftests are not kernel code and are user-space.

Therefore, because this patch *only* contains changes to Kconfig files, code comments, and selftests, it directly matches the criteria in the prompt. I will return `WorthFuzzing=false`.

6/2

2026/07/28 05:53

tool

set-results

Args:

{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch only contains modifications to Kconfig files, code comments, and selftests. It does not modify any executable kernel source code.",
  "WorthFuzzing": false
}

Results:

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only contains modifications to Kconfig files, code comments, and selftests. It does not modify any executable kernel source 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)