AI Trajectory

Trajectory: (Expand/Collapse All)
Seq	Timestamp	Type	Name	Duration
0/0	2026/08/02 16:39	flow	patch-triage	1m Args: null Results: { "EnableConfigs": [ "BPF_SYSCALL" ], "FocusSymbols": [ "resilient_queued_spin_lock_slowpath", "bpf_res_spin_lock", "bpf_res_spin_lock_irqsave" ], "Reasoning": "The patch modifies the deadlock handling logic in `resilient_queued_spin_lock_slowpath`, which is part of the BPF resilient queued spinlock implementation. This code is reachable from BPF programs using `bpf_res_spin_lock` kfuncs, as well as internally by various BPF maps. It is functional and should be fuzzed.", "WorthFuzzing": true }
1/1	2026/08/02 16:39	action	read-patch-diff	0m Args: null Results: { "PatchDiff": "commit 4f6d267d03f8af932f9b1423ab016ef556ae23bd\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Sun Aug 2 16:39:34 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/kernel/bpf/rqspinlock.c b/kernel/bpf/rqspinlock.c\nindex e4e338cdb437c..2129defc4a9a7 100644\n--- a/kernel/bpf/rqspinlock.c\n+++ b/kernel/bpf/rqspinlock.c\n@@ -572,9 +572,10 @@ int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t lock, u32 val)\n \n \t/ Disable queue destruction when we detect deadlocks. */\n \tif (ret == -EDEADLK) {\n-\t\tif (!next)\n+\t\tif (!try_cmpxchg_tail(lock, tail, 0)) {\n \t\t\tnext = smp_cond_load_relaxed(\u0026node-\u003enext, (VAL));\n-\t\tarch_mcs_spin_unlock_contended(\u0026next-\u003elocked);\n+\t\t\tarch_mcs_spin_unlock_contended(\u0026next-\u003elocked);\n+\t\t}\n \t\tgoto err_release_node;\n \t}\n \n" }
2/1	2026/08/02 16:39	agent	patch-evaluator	1m Model: best-expensive Args: null Results: { "EnableConfigs": [ "BPF_SYSCALL" ], "FocusSymbols": [ "resilient_queued_spin_lock_slowpath", "bpf_res_spin_lock", "bpf_res_spin_lock_irqsave" ], "Reasoning": "The patch modifies the deadlock handling logic in `resilient_queued_spin_lock_slowpath`, which is part of the BPF resilient queued spinlock implementation. This code is reachable from BPF programs using `bpf_res_spin_lock` kfuncs, as well as internally by various BPF maps. It is functional and should be fuzzed.", "WorthFuzzing": true } 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 4f6d267d03f8af932f9b1423ab016ef556ae23bd Author: syz-cluster <triage@syzkaller.com> Date: Sun Aug 2 16:39:34 2026 +0000 syz-cluster: applied patch under review diff --git a/kernel/bpf/rqspinlock.c b/kernel/bpf/rqspinlock.c index e4e338cdb437c..2129defc4a9a7 100644 --- a/kernel/bpf/rqspinlock.c +++ b/kernel/bpf/rqspinlock.c @@ -572,9 +572,10 @@ int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t lock, u32 val) / Disable queue destruction when we detect deadlocks. */ if (ret == -EDEADLK) { - if (!next) + if (!try_cmpxchg_tail(lock, tail, 0)) { next = smp_cond_load_relaxed(&node->next, (VAL)); - arch_mcs_spin_unlock_contended(&next->locked); + arch_mcs_spin_unlock_contended(&next->locked); + } goto err_release_node; }
3/2	2026/08/02 16:39	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 2107 output: 40 thoughts: 227 Thoughts: Analyzing a BPF Spinlock Patch Okay, so I've got this patch here that's touching `kernel/bpf/rqspinlock.c`. That immediately flags my attention – it's a very specific area, and anything related to BPF is always worth a close look. The modification seems to be targeting the `resilient_queued_spin_lock_slowpath` function, which suggests a deeper dive into the spinlock implementation is necessary. Let's dissect the code snippet itself. They've introduced a conditional within the deadlock handling (`-EDEADLK`). It looks like they're trying to improve how the lock behaves when a deadlock is detected. The original code unconditionally checked `if (!next)`. Now, they've replaced that with a `try_cmpxchg_tail` call and then the `arch_mcs_spin_unlock_contended` operation is performed unconditionally. This implies a potentially more robust mechanism for handling contended spinlock unlocking in the presence of deadlocks. The `try_cmpxchg_tail` is interesting; it suggests an attempt to atomically update the tail of the lock queue, which would make sense. This is a fundamental change to the spinlock itself, so I need to understand its context within BPF. What configurations are required for this to be active? What other functions in `rqspinlock.c` might be affected by this change? I'll need to check the file and surrounding code to get the complete picture. The goal will be to understand the impact on performance and correctness, and whether this change introduces any subtle side effects in the BPF environment.
4/2	2026/08/02 16:39	tool	grepper	0m Args: { "Expression": "resilient_queued_spin_lock_slowpath", "PathPrefix": "kernel/bpf/rqspinlock.c" } Results: { "Output": "kernel/bpf/rqspinlock.c=261=int __lockfunc resilient_tas_spin_lock(rqspinlock_t lock)\n--\nkernel/bpf/rqspinlock.c-269-\t deadlock detection entry when queued spinlocks are disabled, or from\nkernel/bpf/rqspinlock.c:270:\t * resilient_queued_spin_lock_slowpath after grabbing the deadlock\nkernel/bpf/rqspinlock.c-271-\t * detection entry. No need to obtain it here.\n--\nkernel/bpf/rqspinlock.c=305=static DEFINE_PER_CPU_ALIGNED(struct qnode, rqnodes[_Q_MAX_NODES]);\n--\nkernel/bpf/rqspinlock.c-313-/*\nkernel/bpf/rqspinlock.c:314: resilient_queued_spin_lock_slowpath - acquire the queued spinlock\nkernel/bpf/rqspinlock.c-315- * @lock: Pointer to queued spinlock structure\n--\nkernel/bpf/rqspinlock.c-338- /\nkernel/bpf/rqspinlock.c:339:int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t lock, u32 val)\nkernel/bpf/rqspinlock.c-340-{\n--\nkernel/bpf/rqspinlock.c-666-}\nkernel/bpf/rqspinlock.c:667:EXPORT_SYMBOL_GPL(resilient_queued_spin_lock_slowpath);\nkernel/bpf/rqspinlock.c-668-\n" }
5/2	2026/08/02 16:39	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 3109 output: 28 thoughts: 18 Thoughts: Here's my take on those thoughts: Kconfig Dive for BPF Spinlock Okay, so I need to track down the configuration options that control the build of `kernel/bpf/rqspinlock.c`. I need to figure out how that specific file gets included in the kernel. My first instinct, and the most logical starting point, is to examine the `Kconfig` files. That's where all the build-time configuration settings are defined, and where the dependencies are laid out. I need to figure out what options, if any, directly influence its inclusion, or if it's indirectly controlled through some broader BPF or scheduler configuration. Time to dig in and see what the build system is using.
6/2	2026/08/02 16:39	tool	grepper	0m Args: { "Expression": "rqspinlock", "PathPrefix": "kernel/bpf/Makefile" } Results: { "Output": "kernel/bpf/Makefile=17=obj-$(CONFIG_BPF_JIT) += trampoline.o\nkernel/bpf/Makefile:18:obj-$(CONFIG_BPF_SYSCALL) += btf.o memalloc.o rqspinlock.o stream.o\nkernel/bpf/Makefile-19-ifeq ($(CONFIG_MMU)$(CONFIG_64BIT),yy)\n--\nkernel/bpf/Makefile=75=CFLAGS_REMOVE_ringbuf.o = $(CC_FLAGS_FTRACE)\nkernel/bpf/Makefile:76:CFLAGS_REMOVE_rqspinlock.o = $(CC_FLAGS_FTRACE)\n" }
7/2	2026/08/02 16:39	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 3470 output: 31 thoughts: 77 Thoughts: Analyzing the `resilient_queued_spin_lock_slowpath` Function Okay, so I see this `resilient_queued_spin_lock_slowpath` function is involved, and it looks like it's only compiled when `CONFIG_BPF_SYSCALL` is enabled. That's a good starting point. I need to figure out the exact conditions under which this function will be active. Let's quickly check if there are any other configuration dependencies beyond the obvious one. The first thing I'll do is dive into `kernel/bpf/rqspinlock.c` and hunt for any `#ifdef` directives surrounding the definition or usage of `resilient_queued_spin_lock_slowpath`. I'm looking for anything that might further refine the compilation or behavior of this function, besides just the presence of `CONFIG_BPF_SYSCALL`. Finding these conditions will provide a clearer picture of how this function fits into the larger architecture. I want to build a complete mental model of its activation profile.
8/2	2026/08/02 16:39	tool	grepper	0m Args: { "Expression": "#ifdef", "PathPrefix": "kernel/bpf/rqspinlock.c" } Results: { "Output": "kernel/bpf/rqspinlock.c-25-#include \u003casm/byteorder.h\u003e\nkernel/bpf/rqspinlock.c:26:#ifdef CONFIG_QUEUED_SPINLOCKS\nkernel/bpf/rqspinlock.c-27-#include \u003casm/qspinlock.h\u003e\n--\nkernel/bpf/rqspinlock.c-35- */\nkernel/bpf/rqspinlock.c:36:#ifdef CONFIG_QUEUED_SPINLOCKS\nkernel/bpf/rqspinlock.c-37-#include \"../locking/qspinlock.h\"\n--\nkernel/bpf/rqspinlock.c=295=EXPORT_SYMBOL_GPL(resilient_tas_spin_lock);\nkernel/bpf/rqspinlock.c-296-\nkernel/bpf/rqspinlock.c:297:#ifdef CONFIG_QUEUED_SPINLOCKS\nkernel/bpf/rqspinlock.c-298-\n" }
9/2	2026/08/02 16:39	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 4032 output: 38 thoughts: 51 Thoughts: Okay, here's my take on those thoughts, framed as an expert's internal monologue: Investigating a Spinlock Dependency Alright, so I see that `resilient_queued_spin_lock_slowpath` is demanding `CONFIG_QUEUED_SPINLOCKS`. That's the key. I need to understand why. It's time to dig into the source. Specifically, I should check out `kernel/bpf/rqspinlock.c`, and I'll jump straight to line 297. That's usually where the meat of a check like this resides. I'm expecting to find the actual dependency check or implementation that's triggered when the CONFIG option is enabled. Time to get to it.
10/2	2026/08/02 16:39	tool	read-file	0m Args: { "File": "kernel/bpf/rqspinlock.c", "FirstLine": 290, "LineCount": 100 } Results: { "Contents": " 290:\t\treturn 0;\n 291:\tout:\n 292:\t\trelease_held_lock_entry();\n 293:\t\treturn ret;\n 294:\t}\n 295:\tEXPORT_SYMBOL_GPL(resilient_tas_spin_lock);\n 296:\t\n 297:\t#ifdef CONFIG_QUEUED_SPINLOCKS\n 298:\t\n 299:\t/\n 300:\t Per-CPU queue node structures; we can never have more than 4 nested\n 301:\t * contexts: task, softirq, hardirq, nmi.\n 302:\t \n 303:\t Exactly fits one 64-byte cacheline on a 64-bit architecture.\n 304:\t /\n 305:\tstatic DEFINE_PER_CPU_ALIGNED(struct qnode, rqnodes[_Q_MAX_NODES]);\n 306:\t\n 307:\t#ifndef res_smp_cond_load_acquire\n 308:\t#define res_smp_cond_load_acquire(v, c) smp_cond_load_acquire(v, c)\n 309:\t#endif\n 310:\t\n 311:\t#define res_atomic_cond_read_acquire(v, c) res_smp_cond_load_acquire(\u0026(v)-\u003ecounter, (c))\n 312:\t\n 313:\t/\n 314:\t resilient_queued_spin_lock_slowpath - acquire the queued spinlock\n 315:\t * @lock: Pointer to queued spinlock structure\n 316:\t * @val: Current value of the queued spinlock 32-bit word\n 317:\t \n 318:\t Return:\n 319:\t * * 0\t\t- Lock was acquired successfully.\n 320:\t * * -EDEADLK\t- Lock acquisition failed because of AA/ABBA deadlock.\n 321:\t * * -ETIMEDOUT - Lock acquisition failed because of timeout.\n 322:\t \n 323:\t (queue tail, pending bit, lock value)\n 324:\t \n 325:\t fast : slow : unlock\n 326:\t * : :\n 327:\t * uncontended (0,0,0) -:--\u003e (0,0,1) ------------------------------:--\u003e (,,0)\n 328:\t * : \| ^--------.------. / :\n 329:\t * : v \\ \\ \| :\n 330:\t * pending : (0,1,1) +--\u003e (0,1,0) \\ \| :\n 331:\t * : \| ^--' \| \| :\n 332:\t * : v \| \| :\n 333:\t * uncontended : (n,x,y) +--\u003e (n,0,0) --' \| :\n 334:\t * queue : \| ^--' \| :\n 335:\t * : v \| :\n 336:\t * contended : (,x,y) +--\u003e (,0,0) ---\u003e (,0,1) -' :\n 337:\t queue : ^--' :\n 338:\t /\n 339:\tint __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t lock, u32 val)\n 340:\t{\n 341:\t\tstruct mcs_spinlock prev, next, node;\n 342:\t\tstruct rqspinlock_timeout ts;\n 343:\t\tint idx, ret = 0;\n 344:\t\tu32 old, tail;\n 345:\t\n 346:\t\tBUILD_BUG_ON(CONFIG_NR_CPUS \u003e= (1U \u003c\u003c _Q_TAIL_CPU_BITS));\n 347:\t\n 348:\t\tif (resilient_virt_spin_lock_enabled())\n 349:\t\t\treturn resilient_virt_spin_lock(lock);\n 350:\t\n 351:\t\tRES_INIT_TIMEOUT(ts);\n 352:\t\n 353:\t\t/\n 354:\t\t * Wait for in-progress pending-\u003elocked hand-overs with a bounded\n 355:\t\t * number of spins so that we guarantee forward progress.\n 356:\t\t \n 357:\t\t 0,1,0 -\u003e 0,0,1\n 358:\t\t /\n 359:\t\tif (val == _Q_PENDING_VAL) {\n 360:\t\t\tint cnt = _Q_PENDING_LOOPS;\n 361:\t\t\tval = atomic_cond_read_relaxed(\u0026lock-\u003eval,\n 362:\t\t\t\t\t\t (VAL != _Q_PENDING_VAL) \|\| !cnt--);\n 363:\t\t}\n 364:\t\n 365:\t\t/\n 366:\t\t * If we observe any contention; queue.\n 367:\t\t /\n 368:\t\tif (val \u0026 ~_Q_LOCKED_MASK)\n 369:\t\t\tgoto queue;\n 370:\t\n 371:\t\t/\n 372:\t\t * trylock \|\| pending\n 373:\t\t \n 374:\t\t 0,0,* -\u003e 0,1,* -\u003e 0,0,1 pending, trylock\n 375:\t\t /\n 376:\t\tval = queued_fetch_set_pending_acquire(lock);\n 377:\t\n 378:\t\t/\n 379:\t\t * If we observe contention, there is a concurrent locker.\n 380:\t\t \n 381:\t\t Undo and queue; our setting of PENDING might have made the\n 382:\t\t * n,0,0 -\u003e 0,0,0 transition fail and it will now be waiting\n 383:\t\t * on @next to become !NULL.\n 384:\t\t /\n 385:\t\tif (unlikely(val \u0026 ~_Q_LOCKED_MASK)) {\n 386:\t\n 387:\t\t\t/ Undo PENDING if we set it. */\n 388:\t\t\tif (!(val \u0026 _Q_PENDING_MASK))\n 389:\t\t\t\tclear_pending(lock);\n" }
11/2	2026/08/02 16:39	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 5925 output: 28 thoughts: 67 Thoughts: Okay, let's see, my mental gears are turning... Analyzing `resilient_queued_spin_lock_slowpath` Right, so this `resilient_queued_spin_lock_slowpath` function is nestled inside the `#ifdef CONFIG_QUEUED_SPINLOCKS` block. That immediately flags a configuration dependency, of course. I need to figure out the scope of its relevance. Is `CONFIG_QUEUED_SPINLOCKS` the only configuration option at play here, or are there any related ones? I should really confirm this; knowing all the relevant options helps me understand the complete picture of what's going on. The obvious places to look would be either `kernel/bpf/Kconfig` (since we are discussing the kernel) or maybe even `init/Kconfig` to see if `QUEUED_SPINLOCKS` is defined there. I need to dive into those Kconfig files and verify. That should give me a solid understanding of the context.
12/2	2026/08/02 16:40	tool	grepper	0m Args: { "Expression": "config QUEUED_SPINLOCKS", "PathPrefix": "" } Results: { "Output": "kernel/Kconfig.locks=239=config ARCH_USE_QUEUED_SPINLOCKS\n--\nkernel/Kconfig.locks-241-\nkernel/Kconfig.locks:242:config QUEUED_SPINLOCKS\nkernel/Kconfig.locks-243-\tdef_bool y if ARCH_USE_QUEUED_SPINLOCKS\n" }
13/2	2026/08/02 16:40	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 6337 output: 38 thoughts: 83 Thoughts: Analyzing Spinlock Configuration and BPF Integration Okay, so I'm digging into how spinlocks are configured in this kernel build. It looks like `QUEUED_SPINLOCKS` is enabled by default, provided `ARCH_USE_QUEUED_SPINLOCKS` is also set. That's the typical behavior I'd expect. Now, here's where it gets interesting. I see that `kernel/bpf/rqspinlock.c` is being compiled only when `CONFIG_BPF_SYSCALL` is enabled. That suggests a direct relationship between BPF (Berkeley Packet Filter) and some specific queued spinlock implementations. I need to understand that. Let me jump into the code and focus on `kernel/bpf/rqspinlock.c`, specifically around line 572. I'm guessing that's where the critical BPF-related spinlock interaction is defined.
14/2	2026/08/02 16:40	tool	read-file	0m Args: { "File": "kernel/bpf/rqspinlock.c", "FirstLine": 550, "LineCount": 100 } Results: { "Contents": " 550:\t\t\t\tprefetchw(next);\n 551:\t\t}\n 552:\t\n 553:\t\t/\n 554:\t\t we're at the head of the waitqueue, wait for the owner \u0026 pending to\n 555:\t\t * go away.\n 556:\t\t \n 557:\t\t ,x,y -\u003e ,0,0\n 558:\t\t \n 559:\t\t this wait loop must use a load-acquire such that we match the\n 560:\t\t * store-release that clears the locked bit and create lock\n 561:\t\t * sequentiality; this is because the set_locked() function below\n 562:\t\t * does not imply a full barrier.\n 563:\t\t \n 564:\t\t We use RES_DEF_TIMEOUT * 2 as the duration, as RES_DEF_TIMEOUT is\n 565:\t\t * meant to span maximum allowed time per critical section, and we may\n 566:\t\t * have both the owner of the lock and the pending bit waiter ahead of\n 567:\t\t * us.\n 568:\t\t /\n 569:\t\tRES_RESET_TIMEOUT(ts, RES_DEF_TIMEOUT 2);\n 570:\t\tval = res_atomic_cond_read_acquire(\u0026lock-\u003eval, !(VAL \u0026 _Q_LOCKED_PENDING_MASK) \|\|\n 571:\t\t\t\t\t\t RES_CHECK_TIMEOUT(ts, ret, _Q_LOCKED_PENDING_MASK));\n 572:\t\n 573:\t\t/* Disable queue destruction when we detect deadlocks. /\n 574:\t\tif (ret == -EDEADLK) {\n 575:\t\t\tif (!try_cmpxchg_tail(lock, tail, 0)) {\n 576:\t\t\t\tnext = smp_cond_load_relaxed(\u0026node-\u003enext, (VAL));\n 577:\t\t\t\tarch_mcs_spin_unlock_contended(\u0026next-\u003elocked);\n 578:\t\t\t}\n 579:\t\t\tgoto err_release_node;\n 580:\t\t}\n 581:\t\n 582:\twaitq_timeout:\n 583:\t\tif (ret) {\n 584:\t\t\t/\n 585:\t\t\t * If the tail is still pointing to us, then we are the final waiter,\n 586:\t\t\t * and are responsible for resetting the tail back to 0. Otherwise, if\n 587:\t\t\t * the cmpxchg operation fails, we signal the next waiter to take exit\n 588:\t\t\t * and try the same. For a waiter with tail node 'n':\n 589:\t\t\t \n 590:\t\t\t n,, -\u003e 0,,\n 591:\t\t\t \n 592:\t\t\t When performing cmpxchg for the whole word (NR_CPUS \u003e 16k), it is\n 593:\t\t\t * possible locked/pending bits keep changing and we see failures even\n 594:\t\t\t * when we remain the head of wait queue. However, eventually,\n 595:\t\t\t * pending bit owner will unset the pending bit, and new waiters\n 596:\t\t\t * will queue behind us. This will leave the lock owner in\n 597:\t\t\t * charge, and it will eventually either set locked bit to 0, or\n 598:\t\t\t * leave it as 1, allowing us to make progress.\n 599:\t\t\t \n 600:\t\t\t We terminate the whole wait queue for two reasons. Firstly,\n 601:\t\t\t * we eschew per-waiter timeouts with one applied at the head of\n 602:\t\t\t * the wait queue. This allows everyone to break out faster\n 603:\t\t\t * once we've seen the owner / pending waiter not responding for\n 604:\t\t\t * the timeout duration from the head. Secondly, it avoids\n 605:\t\t\t * complicated synchronization, because when not leaving in FIFO\n 606:\t\t\t * order, prev's next pointer needs to be fixed up etc.\n 607:\t\t\t /\n 608:\t\t\tif (!try_cmpxchg_tail(lock, tail, 0)) {\n 609:\t\t\t\tnext = smp_cond_load_relaxed(\u0026node-\u003enext, VAL);\n 610:\t\t\t\tWRITE_ONCE(next-\u003elocked, RES_TIMEOUT_VAL);\n 611:\t\t\t}\n 612:\t\t\tlockevent_inc(rqspinlock_lock_timeout);\n 613:\t\t\tgoto err_release_node;\n 614:\t\t}\n 615:\t\n 616:\t\t/\n 617:\t\t * claim the lock:\n 618:\t\t \n 619:\t\t n,0,0 -\u003e 0,0,1 : lock, uncontended\n 620:\t\t * ,,0 -\u003e ,,1 : lock, contended\n 621:\t\t \n 622:\t\t If the queue head is the only one in the queue (lock value == tail)\n 623:\t\t * and nobody is pending, clear the tail code and grab the lock.\n 624:\t\t * Otherwise, we only need to grab the lock.\n 625:\t\t /\n 626:\t\n 627:\t\t/\n 628:\t\t * Note: at this point: (val \u0026 _Q_PENDING_MASK) == 0, because of the\n 629:\t\t * above wait condition, therefore any concurrent setting of\n 630:\t\t * PENDING will make the uncontended transition fail.\n 631:\t\t /\n 632:\t\tif ((val \u0026 _Q_TAIL_MASK) == tail) {\n 633:\t\t\tif (atomic_try_cmpxchg_relaxed(\u0026lock-\u003eval, \u0026val, _Q_LOCKED_VAL))\n 634:\t\t\t\tgoto release; / No contention /\n 635:\t\t}\n 636:\t\n 637:\t\t/\n 638:\t\t * Either somebody is queued behind us or _Q_PENDING_VAL got set\n 639:\t\t * which will then detect the remaining tail and queue behind us\n 640:\t\t * ensuring we'll see a @next.\n 641:\t\t /\n 642:\t\tset_locked(lock);\n 643:\t\n 644:\t\t/\n 645:\t\t * contended path; wait for next if not observed yet, release.\n 646:\t\t */\n 647:\t\tif (!next)\n 648:\t\t\tnext = smp_cond_load_relaxed(\u0026node-\u003enext, (VAL));\n 649:\t\n" }
15/2	2026/08/02 16:40	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 8300 output: 27 thoughts: 193 Thoughts: Fuzzing the Resilient Queued Spin Lock Slow Path Okay, so I've found a promising target: the `resilient_queued_spin_lock_slowpath` function. It's right there, exported, and deeply embedded within the core BPF locking mechanism. It's definitely functional code and well worth a fuzzing campaign. My initial thoughts on the configs needed were a little muddled. I needed to ensure `BPF_SYSCALL` is enabled, obviously. I also thought `QUEUED_SPINLOCKS` was a user-settable option. But after a second look, I realize `QUEUED_SPINLOCKS` is actually a `def_bool`, tied to `ARCH_USE_QUEUED_SPINLOCKS`. In other words, architecture-dependent. So, listing it might not be relevant, and listing `BPF_SYSCALL` is the crucial configuration. Hang on... what about `CONFIG_QUEUED_SPINLOCKS`? Ah, right, that's also not a direct user config, it is selected by the architecture. So the only thing I really need to check is `BPF_SYSCALL`. Now, before I launch into fuzzing, let me quickly double-check that there aren't any other related configs I'm missing...
16/2	2026/08/02 16:40	tool	grepper	0m Args: { "Expression": "config BPF_SYSCALL", "PathPrefix": "" } Results: { "Output": "kernel/bpf/Kconfig=25=menu \"BPF subsystem\"\nkernel/bpf/Kconfig-26-\nkernel/bpf/Kconfig:27:config BPF_SYSCALL\nkernel/bpf/Kconfig-28-\tbool \"Enable bpf() system call\"\n" }
17/2	2026/08/02 16:40	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 8893 output: 31 thoughts: 23 Thoughts: Okay, here's my summary, presented as a stream of thought: Checking the Callers of `resilient_queued_spin_lock_slowpath` Right, let's see. I need to understand where this `resilient_queued_spin_lock_slowpath` function is being used. It's a key part of the locking mechanism, and understanding its call sites is critical for analyzing performance, debugging concurrency issues, and maybe even identifying potential bottlenecks or areas for optimization. I'll need to identify all the places this slowpath is entered to get a handle on what might be going on, I need to know the context this is happening in. I'll probably start with a grep or a similar search, I should be able to track down its callers pretty quickly. Hopefully, the naming is clear and I can narrow down the search. This will give me a clear picture of how frequently the slow path is triggered and under what circumstances. The goal here is a full dependency graph!
18/2	2026/08/02 16:40	tool	grepper	0m Args: { "Expression": "resilient_queued_spin_lock_slowpath", "PathPrefix": "" } Results: { "Output": "include/asm-generic/rqspinlock.h=40=extern int resilient_tas_spin_lock(rqspinlock_t lock);\ninclude/asm-generic/rqspinlock.h-41-#ifdef CONFIG_QUEUED_SPINLOCKS\ninclude/asm-generic/rqspinlock.h:42:extern int resilient_queued_spin_lock_slowpath(rqspinlock_t lock, u32 val);\ninclude/asm-generic/rqspinlock.h-43-#endif\n--\ninclude/asm-generic/rqspinlock.h=169=static __always_inline int res_spin_lock(rqspinlock_t lock)\n--\ninclude/asm-generic/rqspinlock.h-188-\t\treturn 0;\ninclude/asm-generic/rqspinlock.h:189:\treturn resilient_queued_spin_lock_slowpath(lock, val);\ninclude/asm-generic/rqspinlock.h-190-}\n--\nkernel/bpf/rqspinlock.c=261=int __lockfunc resilient_tas_spin_lock(rqspinlock_t lock)\n--\nkernel/bpf/rqspinlock.c-269-\t * deadlock detection entry when queued spinlocks are disabled, or from\nkernel/bpf/rqspinlock.c:270:\t * resilient_queued_spin_lock_slowpath after grabbing the deadlock\nkernel/bpf/rqspinlock.c-271-\t * detection entry. No need to obtain it here.\n--\nkernel/bpf/rqspinlock.c=305=static DEFINE_PER_CPU_ALIGNED(struct qnode, rqnodes[_Q_MAX_NODES]);\n--\nkernel/bpf/rqspinlock.c-313-/*\nkernel/bpf/rqspinlock.c:314: resilient_queued_spin_lock_slowpath - acquire the queued spinlock\nkernel/bpf/rqspinlock.c-315- * @lock: Pointer to queued spinlock structure\n--\nkernel/bpf/rqspinlock.c-338- /\nkernel/bpf/rqspinlock.c:339:int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t lock, u32 val)\nkernel/bpf/rqspinlock.c-340-{\n--\nkernel/bpf/rqspinlock.c-666-}\nkernel/bpf/rqspinlock.c:667:EXPORT_SYMBOL_GPL(resilient_queued_spin_lock_slowpath);\nkernel/bpf/rqspinlock.c-668-\n" }
19/2	2026/08/02 16:40	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 9776 output: 25 thoughts: 40 Thoughts: Okay, here's my take on those thoughts, framed as an expert's internal monologue: Investigating the `res_spin_lock` Usage Right, so this is called from `res_spin_lock` within `include/asm-generic/rqspinlock.h`. The `rqspinlock.h` header file suggests we're dealing with resource-aware spinlocks, probably something related to runqueue management. That tells me a lot already, actually. Now, I need to understand the context. Knowing where `res_spin_lock` is used is absolutely critical here. I need to trace its callers. I'll need to use my tools - grep, `cscope`... whatever's appropriate for this codebase - to quickly identify all the call sites of `res_spin_lock`. I need to understand why these locks are being acquired and what data they're protecting to get the bigger picture. Are these runqueue locks, or something else entirely? A quick check should tell me all I need to know about the function calls to `res_spin_lock`, and what context it is called in. From there, I can figure out the problem.
20/2	2026/08/02 16:40	tool	grepper	0m Args: { "Expression": "res_spin_lock", "PathPrefix": "" } Results: { "Output": "\nFull output is too long, showing 500 out of 865 lines.\nUse more precise expression if possible.\n\ninclude/asm-generic/rqspinlock.h=19=struct rqspinlock {\n--\ninclude/asm-generic/rqspinlock.h-28- /\ninclude/asm-generic/rqspinlock.h:29:struct bpf_res_spin_lock {\ninclude/asm-generic/rqspinlock.h-30-\tu32 val;\n--\ninclude/asm-generic/rqspinlock.h=110=static __always_inline void release_held_lock_entry(void)\n--\ninclude/asm-generic/rqspinlock.h-160-/\ninclude/asm-generic/rqspinlock.h:161: res_spin_lock - acquire a queued spinlock\ninclude/asm-generic/rqspinlock.h-162- * @lock: Pointer to queued spinlock structure\n--\ninclude/asm-generic/rqspinlock.h-168- /\ninclude/asm-generic/rqspinlock.h:169:static __always_inline int res_spin_lock(rqspinlock_t lock)\ninclude/asm-generic/rqspinlock.h-170-{\n--\ninclude/asm-generic/rqspinlock.h-180-\t * \u003cNMI\u003e\ninclude/asm-generic/rqspinlock.h:181:\t * res_spin_lock(A) --\u003e missed AA, leads to timeout\ninclude/asm-generic/rqspinlock.h-182-\t * \u003c/NMI\u003e\n--\ninclude/asm-generic/rqspinlock.h-193-\ninclude/asm-generic/rqspinlock.h:194:#define res_spin_lock(lock) ({ grab_held_lock_entry(lock); resilient_tas_spin_lock(lock); })\ninclude/asm-generic/rqspinlock.h-195-\n--\ninclude/asm-generic/rqspinlock.h=198=static __always_inline void res_spin_unlock(rqspinlock_t lock)\n--\ninclude/asm-generic/rqspinlock.h-213-\t \u003cNMI\u003e\ninclude/asm-generic/rqspinlock.h:214:\t * res_spin_lock(A) --\u003e missed AA, leads to timeout\ninclude/asm-generic/rqspinlock.h-215-\t * \u003c/NMI\u003e\n--\ninclude/asm-generic/rqspinlock.h-224-#ifdef CONFIG_QUEUED_SPINLOCKS\ninclude/asm-generic/rqspinlock.h:225:#define raw_res_spin_lock_init(lock) ({ (lock) = (rqspinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; })\ninclude/asm-generic/rqspinlock.h-226-#else\ninclude/asm-generic/rqspinlock.h:227:#define raw_res_spin_lock_init(lock) ({ (lock) = (rqspinlock_t){0}; })\ninclude/asm-generic/rqspinlock.h-228-#endif\ninclude/asm-generic/rqspinlock.h-229-\ninclude/asm-generic/rqspinlock.h:230:#define raw_res_spin_lock(lock) \\\ninclude/asm-generic/rqspinlock.h-231-\t({ \\\n--\ninclude/asm-generic/rqspinlock.h-233-\t\tpreempt_disable(); \\\ninclude/asm-generic/rqspinlock.h:234:\t\t__ret = res_spin_lock(lock);\t \\\ninclude/asm-generic/rqspinlock.h-235-\t\tif (__ret) \\\n--\ninclude/asm-generic/rqspinlock.h-241-\ninclude/asm-generic/rqspinlock.h:242:#define raw_res_spin_lock_irqsave(lock, flags) \\\ninclude/asm-generic/rqspinlock.h-243-\t({ \\\n--\ninclude/asm-generic/rqspinlock.h-246-\t\tpreempt_disable(); \\\ninclude/asm-generic/rqspinlock.h:247:\t\t__ret = res_spin_lock(lock); \\\ninclude/asm-generic/rqspinlock.h-248-\t\tif (__ret) { \\\n--\ninclude/linux/bpf.h=261=struct btf_record {\n--\ninclude/linux/bpf.h-264-\tint spin_lock_off;\ninclude/linux/bpf.h:265:\tint res_spin_lock_off;\ninclude/linux/bpf.h-266-\tint timer_off;\n--\ninclude/linux/bpf.h=346=static inline const char btf_field_type_name(enum btf_field_type type)\n--\ninclude/linux/bpf.h-351-\tcase BPF_RES_SPIN_LOCK:\ninclude/linux/bpf.h:352:\t\treturn \"bpf_res_spin_lock\";\ninclude/linux/bpf.h-353-\tcase BPF_TIMER:\n--\ninclude/linux/bpf.h=388=static inline u32 btf_field_type_size(enum btf_field_type type)\n--\ninclude/linux/bpf.h-393-\tcase BPF_RES_SPIN_LOCK:\ninclude/linux/bpf.h:394:\t\treturn sizeof(struct bpf_res_spin_lock);\ninclude/linux/bpf.h-395-\tcase BPF_TIMER:\n--\ninclude/linux/bpf.h=422=static inline u32 btf_field_type_align(enum btf_field_type type)\n--\ninclude/linux/bpf.h-427-\tcase BPF_RES_SPIN_LOCK:\ninclude/linux/bpf.h:428:\t\treturn __alignof__(struct bpf_res_spin_lock);\ninclude/linux/bpf.h-429-\tcase BPF_TIMER:\n--\nkernel/bpf/arena.c=262=static struct bpf_map arena_map_alloc(union bpf_attr attr)\n--\nkernel/bpf/arena.c-320-\tmutex_init(\u0026arena-\u003ezap_mutex);\nkernel/bpf/arena.c:321:\traw_res_spin_lock_init(\u0026arena-\u003espinlock);\nkernel/bpf/arena.c-322-\terr = populate_pgtable_except_pte(arena);\n--\nkernel/bpf/arena.c=473=static vm_fault_t arena_vm_fault(struct vm_fault vmf)\n--\nkernel/bpf/arena.c-485-\nkernel/bpf/arena.c:486:\tif (raw_res_spin_lock_irqsave(\u0026arena-\u003espinlock, flags))\nkernel/bpf/arena.c-487-\t\t/* Make a reasonable effort to address impossible case /\n--\nkernel/bpf/arena.c=659=static long arena_alloc_pages(struct bpf_arena arena, long uaddr, long page_cnt, int node_id,\n--\nkernel/bpf/arena.c-701-\nkernel/bpf/arena.c:702:\tif (raw_res_spin_lock_irqsave(\u0026arena-\u003espinlock, flags))\nkernel/bpf/arena.c-703-\t\tgoto out_free_pages;\n--\nkernel/bpf/arena.c=838=static void arena_free_pages(struct bpf_arena arena, long uaddr, long page_cnt, bool sleepable)\n--\nkernel/bpf/arena.c-866-\nkernel/bpf/arena.c:867:\tret = raw_res_spin_lock_irqsave(\u0026arena-\u003espinlock, flags);\nkernel/bpf/arena.c-868-\n--\nkernel/bpf/arena.c=928=static int arena_reserve_pages(struct bpf_arena arena, long uaddr, u32 page_cnt)\n--\nkernel/bpf/arena.c-942-\nkernel/bpf/arena.c:943:\tif (raw_res_spin_lock_irqsave(\u0026arena-\u003espinlock, flags))\nkernel/bpf/arena.c-944-\t\treturn -EBUSY;\n--\nkernel/bpf/arena.c=962=static void arena_free_worker(struct work_struct work)\n--\nkernel/bpf/arena.c-975-\nkernel/bpf/arena.c:976:\tif (raw_res_spin_lock_irqsave(\u0026arena-\u003espinlock, flags)) {\nkernel/bpf/arena.c-977-\t\tschedule_work(work);\n--\nkernel/bpf/bpf_local_storage.c=243=static int bpf_selem_unlink_map(struct bpf_local_storage_elem selem)\n--\nkernel/bpf/bpf_local_storage.c-254-\tb = select_bucket(smap, local_storage);\nkernel/bpf/bpf_local_storage.c:255:\terr = raw_res_spin_lock_irqsave(\u0026b-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-256-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=270=int bpf_selem_link_map(struct bpf_local_storage_map smap,\n--\nkernel/bpf/bpf_local_storage.c-279-\nkernel/bpf/bpf_local_storage.c:280:\terr = raw_res_spin_lock_irqsave(\u0026b-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-281-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=300=int bpf_selem_unlink(struct bpf_local_storage_elem selem)\n--\nkernel/bpf/bpf_local_storage.c-317-\nkernel/bpf/bpf_local_storage.c:318:\terr = raw_res_spin_lock_irqsave(\u0026local_storage-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-319-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=350=static void bpf_selem_unlink_nofail(struct bpf_local_storage_elem selem,\n--\nkernel/bpf/bpf_local_storage.c-363-\t\tb = b ? : select_bucket(smap, local_storage);\nkernel/bpf/bpf_local_storage.c:364:\t\terr = raw_res_spin_lock_irqsave(\u0026b-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-365-\t\tif (!err) {\n--\nkernel/bpf/bpf_local_storage.c-384-\t\t destroy(selem1) will be able to free the special field associated\nkernel/bpf/bpf_local_storage.c:385:\t\t * with selem1 as raw_res_spin_lock_irqsave() returns -ETIMEDOUT.\nkernel/bpf/bpf_local_storage.c-386-\t\t /\n--\nkernel/bpf/bpf_local_storage.c-392-\tif (local_storage) {\nkernel/bpf/bpf_local_storage.c:393:\t\terr = raw_res_spin_lock_irqsave(\u0026local_storage-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-394-\t\tif (!err) {\n--\nkernel/bpf/bpf_local_storage.c=441=void __bpf_local_storage_insert_cache(struct bpf_local_storage local_storage,\n--\nkernel/bpf/bpf_local_storage.c-452-\t /\nkernel/bpf/bpf_local_storage.c:453:\terr = raw_res_spin_lock_irqsave(\u0026local_storage-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-454-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=476=int bpf_local_storage_alloc(void owner,\n--\nkernel/bpf/bpf_local_storage.c-497-\tINIT_HLIST_HEAD(\u0026storage-\u003elist);\nkernel/bpf/bpf_local_storage.c:498:\traw_res_spin_lock_init(\u0026storage-\u003elock);\nkernel/bpf/bpf_local_storage.c-499-\tstorage-\u003eowner = owner;\n--\nkernel/bpf/bpf_local_storage.c-505-\tb = select_bucket(smap, storage);\nkernel/bpf/bpf_local_storage.c:506:\terr = raw_res_spin_lock_irqsave(\u0026b-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-507-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=547=bpf_local_storage_update(void owner, struct bpf_local_storage_map smap,\n--\nkernel/bpf/bpf_local_storage.c-610-\nkernel/bpf/bpf_local_storage.c:611:\terr = raw_res_spin_lock_irqsave(\u0026local_storage-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-612-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c-639-\nkernel/bpf/bpf_local_storage.c:640:\terr = raw_res_spin_lock_irqsave(\u0026b-\u003elock, b_flags);\nkernel/bpf/bpf_local_storage.c-641-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=773=bpf_local_storage_map_alloc(union bpf_attr attr,\n--\nkernel/bpf/bpf_local_storage.c-799-\t\tINIT_HLIST_HEAD(\u0026smap-\u003ebuckets[i].list);\nkernel/bpf/bpf_local_storage.c:800:\t\traw_res_spin_lock_init(\u0026smap-\u003ebuckets[i].lock);\nkernel/bpf/bpf_local_storage.c-801-\t}\n--\nkernel/bpf/bpf_lru_list.c=296=static void bpf_lru_list_push_free(struct bpf_lru_list l,\n--\nkernel/bpf/bpf_lru_list.c-303-\nkernel/bpf/bpf_lru_list.c:304:\tif (raw_res_spin_lock_irqsave(\u0026l-\u003elock, flags)) {\nkernel/bpf/bpf_lru_list.c-305-\t\tWRITE_ONCE(node-\u003epending_free, 1);\n--\nkernel/bpf/bpf_lru_list.c=312=static void bpf_lru_list_pop_free_to_local(struct bpf_lru lru,\n--\nkernel/bpf/bpf_lru_list.c-319-\nkernel/bpf/bpf_lru_list.c:320:\tif (raw_res_spin_lock(\u0026l-\u003elock))\nkernel/bpf/bpf_lru_list.c-321-\t\treturn;\n--\nkernel/bpf/bpf_lru_list.c=403=static struct bpf_lru_node bpf_percpu_lru_pop_free(struct bpf_lru lru,\n--\nkernel/bpf/bpf_lru_list.c-413-\nkernel/bpf/bpf_lru_list.c:414:\tif (raw_res_spin_lock_irqsave(\u0026l-\u003elock, flags))\nkernel/bpf/bpf_lru_list.c-415-\t\treturn NULL;\n--\nkernel/bpf/bpf_lru_list.c=436=static struct bpf_lru_node bpf_common_lru_pop_free(struct bpf_lru lru,\n--\nkernel/bpf/bpf_lru_list.c-447-\nkernel/bpf/bpf_lru_list.c:448:\tif (raw_res_spin_lock_irqsave(\u0026loc_l-\u003elock, flags))\nkernel/bpf/bpf_lru_list.c-449-\t\treturn NULL;\n--\nkernel/bpf/bpf_lru_list.c-482-\nkernel/bpf/bpf_lru_list.c:483:\t\tif (!raw_res_spin_lock_irqsave(\u0026steal_loc_l-\u003elock, flags)) {\nkernel/bpf/bpf_lru_list.c-484-\t\t\tnode = __local_list_pop_free(steal_loc_l);\n--\nkernel/bpf/bpf_lru_list.c-497-\nkernel/bpf/bpf_lru_list.c:498:\tif (raw_res_spin_lock_irqsave(\u0026loc_l-\u003elock, flags)) {\nkernel/bpf/bpf_lru_list.c-499-\t\t/\n--\nkernel/bpf/bpf_lru_list.c=525=static void bpf_common_lru_push_free(struct bpf_lru lru,\n--\nkernel/bpf/bpf_lru_list.c-539-\nkernel/bpf/bpf_lru_list.c:540:\t\tif (raw_res_spin_lock_irqsave(\u0026loc_l-\u003elock, flags)) {\nkernel/bpf/bpf_lru_list.c-541-\t\t\tWRITE_ONCE(node-\u003epending_free, 1);\n--\nkernel/bpf/bpf_lru_list.c=565=static void bpf_percpu_lru_push_free(struct bpf_lru lru,\n--\nkernel/bpf/bpf_lru_list.c-572-\nkernel/bpf/bpf_lru_list.c:573:\tif (raw_res_spin_lock_irqsave(\u0026l-\u003elock, flags)) {\nkernel/bpf/bpf_lru_list.c-574-\t\tWRITE_ONCE(node-\u003epending_free, 1);\n--\nkernel/bpf/bpf_lru_list.c=656=static void bpf_lru_locallist_init(struct bpf_lru_locallist loc_l, int cpu)\n--\nkernel/bpf/bpf_lru_list.c-662-\nkernel/bpf/bpf_lru_list.c:663:\traw_res_spin_lock_init(\u0026loc_l-\u003elock);\nkernel/bpf/bpf_lru_list.c-664-}\n--\nkernel/bpf/bpf_lru_list.c=666=static void bpf_lru_list_init(struct bpf_lru_list l)\n--\nkernel/bpf/bpf_lru_list.c-677-\nkernel/bpf/bpf_lru_list.c:678:\traw_res_spin_lock_init(\u0026l-\u003elock);\nkernel/bpf/bpf_lru_list.c-679-}\n--\nkernel/bpf/btf.c=3655=static int btf_get_field_type(const struct btf btf, const struct btf_type var_type,\n--\nkernel/bpf/btf.c-3663-\t\t{ BPF_SPIN_LOCK, \"bpf_spin_lock\", true },\nkernel/bpf/btf.c:3664:\t\t{ BPF_RES_SPIN_LOCK, \"bpf_res_spin_lock\", true },\nkernel/bpf/btf.c-3665-\t\t{ BPF_TIMER, \"bpf_timer\", true },\n--\nkernel/bpf/btf.c=4118=struct btf_record btf_parse_fields(const struct btf btf, const struct btf_type t,\n--\nkernel/bpf/btf.c-4140-\trec-\u003espin_lock_off = -EINVAL;\nkernel/bpf/btf.c:4141:\trec-\u003eres_spin_lock_off = -EINVAL;\nkernel/bpf/btf.c-4142-\trec-\u003etimer_off = -EINVAL;\n--\nkernel/bpf/btf.c-4172-\t\t\t/ Cache offset for faster lookup at runtime /\nkernel/bpf/btf.c:4173:\t\t\trec-\u003eres_spin_lock_off = rec-\u003efields[i].offset;\nkernel/bpf/btf.c-4174-\t\t\tbreak;\n--\nkernel/bpf/btf.c-4221-\nkernel/bpf/btf.c:4222:\tif (rec-\u003espin_lock_off \u003e= 0 \u0026\u0026 rec-\u003eres_spin_lock_off \u003e= 0) {\nkernel/bpf/btf.c-4223-\t\tret = -EINVAL;\n--\nkernel/bpf/btf.c-4229-\t btf_record_has_field(rec, BPF_RB_ROOT)) \u0026\u0026\nkernel/bpf/btf.c:4230:\t\t (rec-\u003espin_lock_off \u003c 0 \u0026\u0026 rec-\u003eres_spin_lock_off \u003c 0)) {\nkernel/bpf/btf.c-4231-\t\tret = -EINVAL;\n--\nkernel/bpf/hashtab.c=139=static void htab_init_buckets(struct bpf_htab htab)\n--\nkernel/bpf/hashtab.c-144-\t\tINIT_HLIST_NULLS_HEAD(\u0026htab-\u003ebuckets[i].head, i);\nkernel/bpf/hashtab.c:145:\t\traw_res_spin_lock_init(\u0026htab-\u003ebuckets[i].raw_lock);\nkernel/bpf/hashtab.c-146-\t\tcond_resched();\n--\nkernel/bpf/hashtab.c=150=static inline int htab_lock_bucket(struct bucket b, unsigned long pflags)\n--\nkernel/bpf/hashtab.c-154-\nkernel/bpf/hashtab.c:155:\tret = raw_res_spin_lock_irqsave(\u0026b-\u003eraw_lock, flags);\nkernel/bpf/hashtab.c-156-\tif (ret)\n--\nkernel/bpf/lpm_trie.c=322=static long trie_update_elem(struct bpf_map map,\n--\nkernel/bpf/lpm_trie.c-345-\nkernel/bpf/lpm_trie.c:346:\tret = raw_res_spin_lock_irqsave(\u0026trie-\u003elock, irq_flags);\nkernel/bpf/lpm_trie.c-347-\tif (ret)\n--\nkernel/bpf/lpm_trie.c=457=static long trie_delete_elem(struct bpf_map map, void _key)\n--\nkernel/bpf/lpm_trie.c-471-\nkernel/bpf/lpm_trie.c:472:\tret = raw_res_spin_lock_irqsave(\u0026trie-\u003elock, irq_flags);\nkernel/bpf/lpm_trie.c-473-\tif (ret)\n--\nkernel/bpf/lpm_trie.c=571=static struct bpf_map trie_alloc(union bpf_attr attr)\n--\nkernel/bpf/lpm_trie.c-597-\nkernel/bpf/lpm_trie.c:598:\traw_res_spin_lock_init(\u0026trie-\u003elock);\nkernel/bpf/lpm_trie.c-599-\n--\nkernel/bpf/percpu_freelist.c=6=int pcpu_freelist_init(struct pcpu_freelist s)\n--\nkernel/bpf/percpu_freelist.c-16-\nkernel/bpf/percpu_freelist.c:17:\t\traw_res_spin_lock_init(\u0026head-\u003elock);\nkernel/bpf/percpu_freelist.c-18-\t\thead-\u003efirst = NULL;\n--\nkernel/bpf/percpu_freelist.c=35=static inline bool ___pcpu_freelist_push(struct pcpu_freelist_head head,\n--\nkernel/bpf/percpu_freelist.c-37-{\nkernel/bpf/percpu_freelist.c:38:\tif (raw_res_spin_lock(\u0026head-\u003elock))\nkernel/bpf/percpu_freelist.c-39-\t\treturn false;\n--\nkernel/bpf/percpu_freelist.c=45=void __pcpu_freelist_push(struct pcpu_freelist s,\n--\nkernel/bpf/percpu_freelist.c-58-\t\t\thead = per_cpu_ptr(s-\u003efreelist, cpu);\nkernel/bpf/percpu_freelist.c:59:\t\t\tif (raw_res_spin_lock(\u0026head-\u003elock))\nkernel/bpf/percpu_freelist.c-60-\t\t\t\tcontinue;\n--\nkernel/bpf/percpu_freelist.c=100=static struct pcpu_freelist_node ___pcpu_freelist_pop(struct pcpu_freelist s)\n--\nkernel/bpf/percpu_freelist.c-109-\t\t\tcontinue;\nkernel/bpf/percpu_freelist.c:110:\t\tif (raw_res_spin_lock(\u0026head-\u003elock))\nkernel/bpf/percpu_freelist.c-111-\t\t\tcontinue;\n--\nkernel/bpf/queue_stack_maps.c=65=static struct bpf_map queue_stack_map_alloc(union bpf_attr attr)\n--\nkernel/bpf/queue_stack_maps.c-81-\nkernel/bpf/queue_stack_maps.c:82:\traw_res_spin_lock_init(\u0026qs-\u003elock);\nkernel/bpf/queue_stack_maps.c-83-\n--\nkernel/bpf/queue_stack_maps.c=95=static long __queue_map_get(struct bpf_map map, void value, bool delete)\n--\nkernel/bpf/queue_stack_maps.c-101-\nkernel/bpf/queue_stack_maps.c:102:\tif (raw_res_spin_lock_irqsave(\u0026qs-\u003elock, flags))\nkernel/bpf/queue_stack_maps.c-103-\t\treturn -EBUSY;\n--\nkernel/bpf/queue_stack_maps.c=125=static long __stack_map_get(struct bpf_map map, void value, bool delete)\n--\nkernel/bpf/queue_stack_maps.c-132-\nkernel/bpf/queue_stack_maps.c:133:\tif (raw_res_spin_lock_irqsave(\u0026qs-\u003elock, flags))\nkernel/bpf/queue_stack_maps.c-134-\t\treturn -EBUSY;\n--\nkernel/bpf/queue_stack_maps.c=182=static long queue_stack_map_push_elem(struct bpf_map map, void value,\n--\nkernel/bpf/queue_stack_maps.c-198-\nkernel/bpf/queue_stack_maps.c:199:\tif (raw_res_spin_lock_irqsave(\u0026qs-\u003elock, irq_flags))\nkernel/bpf/queue_stack_maps.c-200-\t\treturn -EBUSY;\n--\nkernel/bpf/ringbuf.c=172=static struct bpf_ringbuf bpf_ringbuf_alloc(size_t data_sz, int numa_node, bool overwrite_mode)\n--\nkernel/bpf/ringbuf.c-179-\nkernel/bpf/ringbuf.c:180:\traw_res_spin_lock_init(\u0026rb-\u003espinlock);\nkernel/bpf/ringbuf.c-181-\tatomic_set(\u0026rb-\u003ebusy, 0);\n--\nkernel/bpf/ringbuf.c=463=static void __bpf_ringbuf_reserve(struct bpf_ringbuf rb, u64 size)\n--\nkernel/bpf/ringbuf.c-477-\nkernel/bpf/ringbuf.c:478:\tif (raw_res_spin_lock_irqsave(\u0026rb-\u003espinlock, flags))\nkernel/bpf/ringbuf.c-479-\t\treturn NULL;\n--\nkernel/bpf/rqspinlock.c=261=int __lockfunc resilient_tas_spin_lock(rqspinlock_t lock)\n--\nkernel/bpf/rqspinlock.c-267-\t/\nkernel/bpf/rqspinlock.c:268:\t We are either called directly from res_spin_lock after grabbing the\nkernel/bpf/rqspinlock.c-269-\t * deadlock detection entry when queued spinlocks are disabled, or from\n--\nkernel/bpf/rqspinlock.c=673=static void bpf_prog_report_rqspinlock_violation(const char str, void lock, bool irqsave)\n--\nkernel/bpf/rqspinlock.c-682-\tbpf_stream_stage(ss, prog, BPF_STDERR, ({\nkernel/bpf/rqspinlock.c:683:\t\tbpf_stream_printk(ss, \"ERROR: %s for bpf_res_spin_lock%s\\n\", str, irqsave ? \"_irqsave\" : \"\");\nkernel/bpf/rqspinlock.c-684-\t\tbpf_stream_printk(ss, \"Attempted lock = 0x%px\\n\", lock);\n--\nkernel/bpf/rqspinlock.c-693-\nkernel/bpf/rqspinlock.c:694:__bpf_kfunc int bpf_res_spin_lock(struct bpf_res_spin_lock lock)\nkernel/bpf/rqspinlock.c-695-{\n--\nkernel/bpf/rqspinlock.c-697-\nkernel/bpf/rqspinlock.c:698:\tBUILD_BUG_ON(sizeof(rqspinlock_t) != sizeof(struct bpf_res_spin_lock));\nkernel/bpf/rqspinlock.c-699-\nkernel/bpf/rqspinlock.c-700-\tpreempt_disable();\nkernel/bpf/rqspinlock.c:701:\tret = res_spin_lock((rqspinlock_t )lock);\nkernel/bpf/rqspinlock.c-702-\tif (unlikely(ret)) {\n--\nkernel/bpf/rqspinlock.c-709-\nkernel/bpf/rqspinlock.c:710:__bpf_kfunc void bpf_res_spin_unlock(struct bpf_res_spin_lock lock)\nkernel/bpf/rqspinlock.c-711-{\n--\nkernel/bpf/rqspinlock.c-715-\nkernel/bpf/rqspinlock.c:716:__bpf_kfunc int bpf_res_spin_lock_irqsave(struct bpf_res_spin_lock lock, unsigned long flags__irq_flag)\nkernel/bpf/rqspinlock.c-717-{\n--\nkernel/bpf/rqspinlock.c-723-\tlocal_irq_save(flags);\nkernel/bpf/rqspinlock.c:724:\tret = res_spin_lock((rqspinlock_t )lock);\nkernel/bpf/rqspinlock.c-725-\tif (unlikely(ret)) {\n--\nkernel/bpf/rqspinlock.c-734-\nkernel/bpf/rqspinlock.c:735:__bpf_kfunc void bpf_res_spin_unlock_irqrestore(struct bpf_res_spin_lock lock, unsigned long flags__irq_flag)\nkernel/bpf/rqspinlock.c-736-{\n--\nkernel/bpf/rqspinlock.c=747=BTF_KFUNCS_START(rqspinlock_kfunc_ids)\nkernel/bpf/rqspinlock.c:748:BTF_ID_FLAGS(func, bpf_res_spin_lock, KF_RET_NULL)\nkernel/bpf/rqspinlock.c-749-BTF_ID_FLAGS(func, bpf_res_spin_unlock)\nkernel/bpf/rqspinlock.c:750:BTF_ID_FLAGS(func, bpf_res_spin_lock_irqsave, KF_RET_NULL)\nkernel/bpf/rqspinlock.c-751-BTF_ID_FLAGS(func, bpf_res_spin_unlock_irqrestore)\n--\nkernel/bpf/verifier.c=6976=static int process_spin_lock(struct bpf_verifier_env env, struct bpf_reg_state reg, argno_t argno, int flags)\n--\nkernel/bpf/verifier.c-7013-\t}\nkernel/bpf/verifier.c:7014:\tspin_lock_off = is_res_lock ? rec-\u003eres_spin_lock_off : rec-\u003espin_lock_off;\nkernel/bpf/verifier.c-7015-\tif (spin_lock_off != val) {\n--\nkernel/bpf/verifier.c=10823=BTF_ID(struct, bpf_wq)\nkernel/bpf/verifier.c:10824:BTF_ID(struct, bpf_res_spin_lock)\nkernel/bpf/verifier.c-10825-BTF_ID(struct, bpf_task_work)\n--\nkernel/bpf/verifier.c=10881=static bool is_kfunc_arg_task_work(const struct btf btf, const struct btf_param arg)\n--\nkernel/bpf/verifier.c-10885-\nkernel/bpf/verifier.c:10886:static bool is_kfunc_arg_res_spin_lock(const struct btf btf, const struct btf_param arg)\nkernel/bpf/verifier.c-10887-{\n--\nkernel/bpf/verifier.c=11004=enum special_kfunc_type {\n--\nkernel/bpf/verifier.c-11059-\tKF_bpf_remove_dentry_xattr,\nkernel/bpf/verifier.c:11060:\tKF_bpf_res_spin_lock,\nkernel/bpf/verifier.c-11061-\tKF_bpf_res_spin_unlock,\nkernel/bpf/verifier.c:11062:\tKF_bpf_res_spin_lock_irqsave,\nkernel/bpf/verifier.c-11063-\tKF_bpf_res_spin_unlock_irqrestore,\n--\nkernel/bpf/verifier.c=11151=BTF_ID_UNUSED\nkernel/bpf/verifier.c-11152-#endif\nkernel/bpf/verifier.c:11153:BTF_ID(func, bpf_res_spin_lock)\nkernel/bpf/verifier.c-11154-BTF_ID(func, bpf_res_spin_unlock)\nkernel/bpf/verifier.c:11155:BTF_ID(func, bpf_res_spin_lock_irqsave)\nkernel/bpf/verifier.c-11156-BTF_ID(func, bpf_res_spin_unlock_irqrestore)\n--\nkernel/bpf/verifier.c=11258=get_kfunc_ptr_arg_type(struct bpf_verifier_env env, struct bpf_func_state caller,\n--\nkernel/bpf/verifier.c-11329-\nkernel/bpf/verifier.c:11330:\tif (is_kfunc_arg_res_spin_lock(meta-\u003ebtf, \u0026args[arg]))\nkernel/bpf/verifier.c-11331-\t\treturn KF_ARG_PTR_TO_RES_SPIN_LOCK;\n--\nkernel/bpf/verifier.c=11433=static int process_irq_flag(struct bpf_verifier_env env, struct bpf_reg_state reg, argno_t argno,\n--\nkernel/bpf/verifier.c-11439-\tif (meta-\u003efunc_id == special_kfunc_list[KF_bpf_local_irq_save] \|\|\nkernel/bpf/verifier.c:11440:\t meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave]) {\nkernel/bpf/verifier.c-11441-\t\tirq_save = true;\nkernel/bpf/verifier.c:11442:\t\tif (meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave])\nkernel/bpf/verifier.c-11443-\t\t\tkfunc_class = IRQ_LOCK_KFUNC;\n--\nkernel/bpf/verifier.c=11632=static bool is_bpf_graph_api_kfunc(u32 btf_id)\n--\nkernel/bpf/verifier.c-11638-\nkernel/bpf/verifier.c:11639:static bool is_bpf_res_spin_lock_kfunc(u32 btf_id)\nkernel/bpf/verifier.c-11640-{\nkernel/bpf/verifier.c:11641:\treturn btf_id == special_kfunc_list[KF_bpf_res_spin_lock] \|\|\nkernel/bpf/verifier.c-11642-\t btf_id == special_kfunc_list[KF_bpf_res_spin_unlock] \|\|\nkernel/bpf/verifier.c:11643:\t btf_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave] \|\|\nkernel/bpf/verifier.c-11644-\t btf_id == special_kfunc_list[KF_bpf_res_spin_unlock_irqrestore];\n--\nkernel/bpf/verifier.c=11660=static bool kfunc_spin_allowed(u32 btf_id)\n--\nkernel/bpf/verifier.c-11662-\treturn is_bpf_graph_api_kfunc(btf_id) \|\| is_bpf_iter_num_api_kfunc(btf_id) \|\|\nkernel/bpf/verifier.c:11663:\t is_bpf_res_spin_lock_kfunc(btf_id) \|\| is_bpf_arena_kfunc(btf_id) \|\|\nkernel/bpf/verifier.c-11664-\t is_bpf_stream_kfunc(btf_id);\n--\nkernel/bpf/verifier.c=11928=static int check_kfunc_args(struct bpf_verifier_env env, struct bpf_kfunc_call_arg_meta meta,\n--\nkernel/bpf/verifier.c-12499-\nkernel/bpf/verifier.c:12500:\t\t\tif (!is_bpf_res_spin_lock_kfunc(meta-\u003efunc_id))\nkernel/bpf/verifier.c-12501-\t\t\t\treturn -EFAULT;\nkernel/bpf/verifier.c:12502:\t\t\tif (meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_lock] \|\|\nkernel/bpf/verifier.c:12503:\t\t\t meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave])\nkernel/bpf/verifier.c-12504-\t\t\t\tflags \|= PROCESS_SPIN_LOCK;\nkernel/bpf/verifier.c:12505:\t\t\tif (meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave] \|\|\nkernel/bpf/verifier.c-12506-\t\t\t meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_unlock_irqrestore])\n--\nkernel/bpf/verifier.c=12913=static int check_kfunc_call(struct bpf_verifier_env env, struct bpf_insn insn,\n--\nkernel/bpf/verifier.c-12944-\tif (!insn-\u003eoff \u0026\u0026\nkernel/bpf/verifier.c:12945:\t (insn-\u003eimm == special_kfunc_list[KF_bpf_res_spin_lock] \|\|\nkernel/bpf/verifier.c:12946:\t insn-\u003eimm == special_kfunc_list[KF_bpf_res_spin_lock_irqsave])) {\nkernel/bpf/verifier.c-12947-\t\tstruct bpf_verifier_state *branch;\n--\nkernel/bpf/verifier.c-13141-\t\tmark_reg_unknown(env, regs, BPF_REG_0);\nkernel/bpf/verifier.c:13142:\t\tif (meta.btf == btf_vmlinux \u0026\u0026 (meta.func_id == special_kfunc_list[KF_bpf_res_spin_lock] \|\|\nkernel/bpf/verifier.c:13143:\t\t meta.func_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave]))\nkernel/bpf/verifier.c-13144-\t\t\t__mark_reg_const_zero(env, \u0026regs[BPF_REG_0]);\n--\nkernel/locking/locktorture.c=370=static int torture_raw_res_spin_write_lock(int tid __maybe_unused)\nkernel/locking/locktorture.c-371-{\nkernel/locking/locktorture.c:372:\traw_res_spin_lock(\u0026rqspinlock);\nkernel/locking/locktorture.c-373-\treturn 0;\n--\nkernel/locking/locktorture.c=376=static void torture_raw_res_spin_write_unlock(int tid __maybe_unused)\n--\nkernel/locking/locktorture.c-380-\nkernel/locking/locktorture.c:381:static struct lock_torture_ops raw_res_spin_lock_ops = {\nkernel/locking/locktorture.c-382-\t.writelock\t= torture_raw_res_spin_write_lock,\n--\nkernel/locking/locktorture.c-388-\t.readunlock = NULL,\nkernel/locking/locktorture.c:389:\t.name\t\t= \"raw_res_spin_lock\"\nkernel/locking/locktorture.c-390-};\n--\nkernel/locking/locktorture.c=392=static int torture_raw_res_spin_write_lock_irq(int tid __maybe_unused)\n--\nkernel/locking/locktorture.c-395-\nkernel/locking/locktorture.c:396:\traw_res_spin_lock_irqsave(\u0026rqspinlock, flags);\nkernel/locking/locktorture.c-397-\tcxt.cur_ops-\u003eflags = flags;\n--\nkernel/locking/locktorture.c=401=static void torture_raw_res_spin_write_unlock_irq(int tid __maybe_unused)\n--\nkernel/locking/locktorture.c-405-\nkernel/locking/locktorture.c:406:static struct lock_torture_ops raw_res_spin_lock_irq_ops = {\nkernel/locking/locktorture.c-407-\t.writelock\t= torture_raw_res_spin_write_lock_irq,\n\n" }
21/2	2026/08/02 16:40	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 21279 output: 37 thoughts: 202 Thoughts: Analyzing BPF Spin Lock Usage Okay, so I'm thinking about this `resilient_queued_spin_lock_slowpath`. I know that function is crucial because it's at the heart of `bpf_res_spin_lock` and `bpf_res_spin_lock_irqsave`, both of which are, of course, BPF kfuncs. It's also utilized by `raw_res_spin_lock`, and that's used across the BPF codebase – arena management, local storage, the LRU list, all of it. Given that widespread usage, it's definitely reachable from BPF syscalls. Therefore, the key symbols I need to focus on right now are `resilient_queued_spin_lock_slowpath`, `bpf_res_spin_lock`, and `bpf_res_spin_lock_irqsave`. I need to confirm that `bpf_res_spin_lock` and `bpf_res_spin_lock_irqsave` aren't exported as standard functions, but are defined purely as kfuncs. Checks internal documentation Yes, they are indeed kfuncs. Now, I'm going to take another look at `kernel/bpf/rqspinlock.c` and make sure I haven't missed anything.
22/2	2026/08/02 16:40	tool	grepper	0m Args: { "Expression": "bpf_res_spin_lock", "PathPrefix": "kernel/bpf/rqspinlock.c" } Results: { "Output": "kernel/bpf/rqspinlock.c=673=static void bpf_prog_report_rqspinlock_violation(const char str, void lock, bool irqsave)\n--\nkernel/bpf/rqspinlock.c-682-\tbpf_stream_stage(ss, prog, BPF_STDERR, ({\nkernel/bpf/rqspinlock.c:683:\t\tbpf_stream_printk(ss, \"ERROR: %s for bpf_res_spin_lock%s\\n\", str, irqsave ? \"_irqsave\" : \"\");\nkernel/bpf/rqspinlock.c-684-\t\tbpf_stream_printk(ss, \"Attempted lock = 0x%px\\n\", lock);\n--\nkernel/bpf/rqspinlock.c-693-\nkernel/bpf/rqspinlock.c:694:__bpf_kfunc int bpf_res_spin_lock(struct bpf_res_spin_lock lock)\nkernel/bpf/rqspinlock.c-695-{\n--\nkernel/bpf/rqspinlock.c-697-\nkernel/bpf/rqspinlock.c:698:\tBUILD_BUG_ON(sizeof(rqspinlock_t) != sizeof(struct bpf_res_spin_lock));\nkernel/bpf/rqspinlock.c-699-\n--\nkernel/bpf/rqspinlock.c-709-\nkernel/bpf/rqspinlock.c:710:__bpf_kfunc void bpf_res_spin_unlock(struct bpf_res_spin_lock lock)\nkernel/bpf/rqspinlock.c-711-{\n--\nkernel/bpf/rqspinlock.c-715-\nkernel/bpf/rqspinlock.c:716:__bpf_kfunc int bpf_res_spin_lock_irqsave(struct bpf_res_spin_lock lock, unsigned long flags__irq_flag)\nkernel/bpf/rqspinlock.c-717-{\n--\nkernel/bpf/rqspinlock.c-734-\nkernel/bpf/rqspinlock.c:735:__bpf_kfunc void bpf_res_spin_unlock_irqrestore(struct bpf_res_spin_lock lock, unsigned long flags__irq_flag)\nkernel/bpf/rqspinlock.c-736-{\n--\nkernel/bpf/rqspinlock.c=747=BTF_KFUNCS_START(rqspinlock_kfunc_ids)\nkernel/bpf/rqspinlock.c:748:BTF_ID_FLAGS(func, bpf_res_spin_lock, KF_RET_NULL)\nkernel/bpf/rqspinlock.c-749-BTF_ID_FLAGS(func, bpf_res_spin_unlock)\nkernel/bpf/rqspinlock.c:750:BTF_ID_FLAGS(func, bpf_res_spin_lock_irqsave, KF_RET_NULL)\nkernel/bpf/rqspinlock.c-751-BTF_ID_FLAGS(func, bpf_res_spin_unlock_irqrestore)\n" }
23/2	2026/08/02 16:40	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 22580 output: 34 thoughts: 101 Thoughts: Analyzing BPF Spin Locks and Configuration Dependencies Okay, so I'm looking at these BPF spin lock functions, specifically `bpf_res_spin_lock` and `bpf_res_spin_lock_irqsave`. They seem like prime candidates to include in `FocusSymbols`. That makes sense. Also, I'm noting that `resilient_queued_spin_lock_slowpath` is the one that's been modified, which is important to remember. Now, the configuration in play here is `BPF_SYSCALL`. But wait a minute... is that all? I need to be sure I've got the full picture. Let's dig into `kernel/bpf/Kconfig` and see if there are any other dependencies associated with `BPF_SYSCALL`. I need to understand all the conditions that might impact this code. Gotta make sure I'm not missing any pieces of the puzzle.
24/2	2026/08/02 16:40	tool	grepper	0m Args: { "Expression": "config BPF_SYSCALL", "PathPrefix": "kernel/bpf/Kconfig" } Results: { "Output": "kernel/bpf/Kconfig=25=menu \"BPF subsystem\"\nkernel/bpf/Kconfig-26-\nkernel/bpf/Kconfig:27:config BPF_SYSCALL\nkernel/bpf/Kconfig-28-\tbool \"Enable bpf() system call\"\n" }
25/2	2026/08/02 16:41	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 23002 output: 154 thoughts: 384 Thoughts: Analyzing a BPF Spinlock Patch Okay, so this is about `BPF_SYSCALL`, nothing too obscure. Let's start by seeing if there are any architecture-specific configurations that might be relevant. Right, `CONFIG_QUEUED_SPINLOCKS` is selected by `ARCH_USE_QUEUED_SPINLOCKS`. Good, good, we can just focus on `BPF_SYSCALL` then. Alright, let's take another look at this patch. It seems to be cleaning up a deadlock scenario. Specifically, it seems like the fix addresses a bug in `resilient_queued_spin_lock_slowpath`. I see the code snippet now, changing the logic where it's handling `EDEADLK`, looks like they're trying to prevent queue destruction on deadlock, with a `try_cmpxchg_tail`. This looks functional and reachable, which is important. This path is definitely called, specifically by the `resilient_queued_spin_lock_slowpath` function. And that's part of the BPF resilient queued spinlock implementation. This spinlock gets used by `bpf_res_spin_lock` and `bpf_res_spin_lock_irqsave` kfuncs, and by BPF maps internally. This is an area we should definitely fuzz.
26/2	2026/08/02 16:41	tool	set-results	0m Args: { "EnableConfigs": [ "BPF_SYSCALL" ], "FocusSymbols": [ "resilient_queued_spin_lock_slowpath", "bpf_res_spin_lock", "bpf_res_spin_lock_irqsave" ], "Reasoning": "The patch modifies the deadlock handling logic in `resilient_queued_spin_lock_slowpath`, which is part of the BPF resilient queued spinlock implementation. This code is reachable from BPF programs using `bpf_res_spin_lock` kfuncs, as well as internally by various BPF maps. It is functional and should be fuzzed.", "WorthFuzzing": true } Results: { "EnableConfigs": [ "BPF_SYSCALL" ], "FocusSymbols": [ "resilient_queued_spin_lock_slowpath", "bpf_res_spin_lock", "bpf_res_spin_lock_irqsave" ], "Reasoning": "The patch modifies the deadlock handling logic in `resilient_queued_spin_lock_slowpath`, which is part of the BPF resilient queued spinlock implementation. This code is reachable from BPF programs using `bpf_res_spin_lock` kfuncs, as well as internally by various BPF maps. It is functional and should be fuzzed.", "WorthFuzzing": true }

{
  "EnableConfigs": [
    "BPF_SYSCALL"
  ],
  "FocusSymbols": [
    "resilient_queued_spin_lock_slowpath",
    "bpf_res_spin_lock",
    "bpf_res_spin_lock_irqsave"
  ],
  "Reasoning": "The patch modifies the deadlock handling logic in `resilient_queued_spin_lock_slowpath`, which is part of the BPF resilient queued spinlock implementation. This code is reachable from BPF programs using `bpf_res_spin_lock` kfuncs, as well as internally by various BPF maps. It is functional and should be fuzzed.",
  "WorthFuzzing": true
}

{
  "PatchDiff": "commit 4f6d267d03f8af932f9b1423ab016ef556ae23bd\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Sun Aug 2 16:39:34 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/kernel/bpf/rqspinlock.c b/kernel/bpf/rqspinlock.c\nindex e4e338cdb437c..2129defc4a9a7 100644\n--- a/kernel/bpf/rqspinlock.c\n+++ b/kernel/bpf/rqspinlock.c\n@@ -572,9 +572,10 @@ int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val)\n \n \t/* Disable queue destruction when we detect deadlocks. */\n \tif (ret == -EDEADLK) {\n-\t\tif (!next)\n+\t\tif (!try_cmpxchg_tail(lock, tail, 0)) {\n \t\t\tnext = smp_cond_load_relaxed(\u0026node-\u003enext, (VAL));\n-\t\tarch_mcs_spin_unlock_contended(\u0026next-\u003elocked);\n+\t\t\tarch_mcs_spin_unlock_contended(\u0026next-\u003elocked);\n+\t\t}\n \t\tgoto err_release_node;\n \t}\n \n"
}

{
  "EnableConfigs": [
    "BPF_SYSCALL"
  ],
  "FocusSymbols": [
    "resilient_queued_spin_lock_slowpath",
    "bpf_res_spin_lock",
    "bpf_res_spin_lock_irqsave"
  ],
  "Reasoning": "The patch modifies the deadlock handling logic in `resilient_queued_spin_lock_slowpath`, which is part of the BPF resilient queued spinlock implementation. This code is reachable from BPF programs using `bpf_res_spin_lock` kfuncs, as well as internally by various BPF maps. It is functional and should be fuzzed.",
  "WorthFuzzing": true
}

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.

For your convenience, here is the diff of the changes:
commit 4f6d267d03f8af932f9b1423ab016ef556ae23bd
Author: syz-cluster <triage@syzkaller.com>
Date:   Sun Aug 2 16:39:34 2026 +0000

    syz-cluster: applied patch under review

diff --git a/kernel/bpf/rqspinlock.c b/kernel/bpf/rqspinlock.c
index e4e338cdb437c..2129defc4a9a7 100644
--- a/kernel/bpf/rqspinlock.c
+++ b/kernel/bpf/rqspinlock.c
@@ -572,9 +572,10 @@ int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val)
 
 	/* Disable queue destruction when we detect deadlocks. */
 	if (ret == -EDEADLK) {
-		if (!next)
+		if (!try_cmpxchg_tail(lock, tail, 0)) {
 			next = smp_cond_load_relaxed(&node->next, (VAL));
-		arch_mcs_spin_unlock_contended(&next->locked);
+			arch_mcs_spin_unlock_contended(&next->locked);
+		}
 		goto err_release_node;
 	}

gemini-3.1-pro-preview

							input: 2107
							output: 40
							thoughts: 227

**Analyzing a BPF Spinlock Patch**

Okay, so I've got this patch here that's touching `kernel/bpf/rqspinlock.c`. That immediately flags my attention – it's a very specific area, and anything related to BPF is always worth a close look. The modification seems to be targeting the `resilient_queued_spin_lock_slowpath` function, which suggests a deeper dive into the spinlock implementation is necessary.

Let's dissect the code snippet itself. They've introduced a conditional within the deadlock handling (`-EDEADLK`). It looks like they're trying to improve how the lock behaves when a deadlock is detected. The original code unconditionally checked `if (!next)`. Now, they've replaced that with a `try_cmpxchg_tail` call and then the `arch_mcs_spin_unlock_contended` operation is performed unconditionally. This implies a potentially more robust mechanism for handling contended spinlock unlocking in the presence of deadlocks. The `try_cmpxchg_tail` is interesting; it suggests an attempt to atomically update the tail of the lock queue, which would make sense.

This is a fundamental change to the spinlock itself, so I need to understand its context within BPF. What configurations are required for this to be active? What other functions in `rqspinlock.c` might be affected by this change? I'll need to check the file and surrounding code to get the complete picture. The goal will be to understand the impact on performance and correctness, and whether this change introduces any subtle side effects in the BPF environment.

{
  "Expression": "resilient_queued_spin_lock_slowpath",
  "PathPrefix": "kernel/bpf/rqspinlock.c"
}

{
  "Output": "kernel/bpf/rqspinlock.c=261=int __lockfunc resilient_tas_spin_lock(rqspinlock_t *lock)\n--\nkernel/bpf/rqspinlock.c-269-\t * deadlock detection entry when queued spinlocks are disabled, or from\nkernel/bpf/rqspinlock.c:270:\t * resilient_queued_spin_lock_slowpath after grabbing the deadlock\nkernel/bpf/rqspinlock.c-271-\t * detection entry. No need to obtain it here.\n--\nkernel/bpf/rqspinlock.c=305=static DEFINE_PER_CPU_ALIGNED(struct qnode, rqnodes[_Q_MAX_NODES]);\n--\nkernel/bpf/rqspinlock.c-313-/**\nkernel/bpf/rqspinlock.c:314: * resilient_queued_spin_lock_slowpath - acquire the queued spinlock\nkernel/bpf/rqspinlock.c-315- * @lock: Pointer to queued spinlock structure\n--\nkernel/bpf/rqspinlock.c-338- */\nkernel/bpf/rqspinlock.c:339:int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val)\nkernel/bpf/rqspinlock.c-340-{\n--\nkernel/bpf/rqspinlock.c-666-}\nkernel/bpf/rqspinlock.c:667:EXPORT_SYMBOL_GPL(resilient_queued_spin_lock_slowpath);\nkernel/bpf/rqspinlock.c-668-\n"
}

gemini-3.1-pro-preview

							input: 3109
							output: 28
							thoughts: 18

Here's my take on those thoughts:

**Kconfig Dive for BPF Spinlock**

Okay, so I need to track down the configuration options that control the build of `kernel/bpf/rqspinlock.c`. I need to figure out how that specific file gets included in the kernel. My first instinct, and the most logical starting point, is to examine the `Kconfig` files. That's where all the build-time configuration settings are defined, and where the dependencies are laid out. I need to figure out what options, if any, directly influence its inclusion, or if it's indirectly controlled through some broader BPF or scheduler configuration. Time to dig in and see what the build system is using.

{
  "Expression": "rqspinlock",
  "PathPrefix": "kernel/bpf/Makefile"
}

{
  "Output": "kernel/bpf/Makefile=17=obj-$(CONFIG_BPF_JIT) += trampoline.o\nkernel/bpf/Makefile:18:obj-$(CONFIG_BPF_SYSCALL) += btf.o memalloc.o rqspinlock.o stream.o\nkernel/bpf/Makefile-19-ifeq ($(CONFIG_MMU)$(CONFIG_64BIT),yy)\n--\nkernel/bpf/Makefile=75=CFLAGS_REMOVE_ringbuf.o = $(CC_FLAGS_FTRACE)\nkernel/bpf/Makefile:76:CFLAGS_REMOVE_rqspinlock.o = $(CC_FLAGS_FTRACE)\n"
}

gemini-3.1-pro-preview

							input: 3470
							output: 31
							thoughts: 77

**Analyzing the `resilient_queued_spin_lock_slowpath` Function**

Okay, so I see this `resilient_queued_spin_lock_slowpath` function is involved, and it looks like it's only compiled when `CONFIG_BPF_SYSCALL` is enabled. That's a good starting point. I need to figure out the exact conditions under which this function will be active.

Let's quickly check if there are any other configuration dependencies beyond the obvious one. The first thing I'll do is dive into `kernel/bpf/rqspinlock.c` and hunt for any `#ifdef` directives surrounding the definition or usage of `resilient_queued_spin_lock_slowpath`. I'm looking for anything that might further refine the compilation or behavior of this function, besides just the presence of `CONFIG_BPF_SYSCALL`. Finding these conditions will provide a clearer picture of how this function fits into the larger architecture. I want to build a complete mental model of its activation profile.

{
  "Expression": "#ifdef",
  "PathPrefix": "kernel/bpf/rqspinlock.c"
}

{
  "Output": "kernel/bpf/rqspinlock.c-25-#include \u003casm/byteorder.h\u003e\nkernel/bpf/rqspinlock.c:26:#ifdef CONFIG_QUEUED_SPINLOCKS\nkernel/bpf/rqspinlock.c-27-#include \u003casm/qspinlock.h\u003e\n--\nkernel/bpf/rqspinlock.c-35- */\nkernel/bpf/rqspinlock.c:36:#ifdef CONFIG_QUEUED_SPINLOCKS\nkernel/bpf/rqspinlock.c-37-#include \"../locking/qspinlock.h\"\n--\nkernel/bpf/rqspinlock.c=295=EXPORT_SYMBOL_GPL(resilient_tas_spin_lock);\nkernel/bpf/rqspinlock.c-296-\nkernel/bpf/rqspinlock.c:297:#ifdef CONFIG_QUEUED_SPINLOCKS\nkernel/bpf/rqspinlock.c-298-\n"
}

gemini-3.1-pro-preview

							input: 4032
							output: 38
							thoughts: 51

Okay, here's my take on those thoughts, framed as an expert's internal monologue:

**Investigating a Spinlock Dependency**

Alright, so I see that `resilient_queued_spin_lock_slowpath` is demanding `CONFIG_QUEUED_SPINLOCKS`. That's the key. I need to understand why. It's time to dig into the source. Specifically, I should check out `kernel/bpf/rqspinlock.c`, and I'll jump straight to line 297. That's usually where the meat of a check like this resides. I'm expecting to find the actual dependency check or implementation that's triggered when the CONFIG option is enabled. Time to get to it.

{
  "File": "kernel/bpf/rqspinlock.c",
  "FirstLine": 290,
  "LineCount": 100
}

{
  "Contents": " 290:\t\treturn 0;\n 291:\tout:\n 292:\t\trelease_held_lock_entry();\n 293:\t\treturn ret;\n 294:\t}\n 295:\tEXPORT_SYMBOL_GPL(resilient_tas_spin_lock);\n 296:\t\n 297:\t#ifdef CONFIG_QUEUED_SPINLOCKS\n 298:\t\n 299:\t/*\n 300:\t * Per-CPU queue node structures; we can never have more than 4 nested\n 301:\t * contexts: task, softirq, hardirq, nmi.\n 302:\t *\n 303:\t * Exactly fits one 64-byte cacheline on a 64-bit architecture.\n 304:\t */\n 305:\tstatic DEFINE_PER_CPU_ALIGNED(struct qnode, rqnodes[_Q_MAX_NODES]);\n 306:\t\n 307:\t#ifndef res_smp_cond_load_acquire\n 308:\t#define res_smp_cond_load_acquire(v, c) smp_cond_load_acquire(v, c)\n 309:\t#endif\n 310:\t\n 311:\t#define res_atomic_cond_read_acquire(v, c) res_smp_cond_load_acquire(\u0026(v)-\u003ecounter, (c))\n 312:\t\n 313:\t/**\n 314:\t * resilient_queued_spin_lock_slowpath - acquire the queued spinlock\n 315:\t * @lock: Pointer to queued spinlock structure\n 316:\t * @val: Current value of the queued spinlock 32-bit word\n 317:\t *\n 318:\t * Return:\n 319:\t * * 0\t\t- Lock was acquired successfully.\n 320:\t * * -EDEADLK\t- Lock acquisition failed because of AA/ABBA deadlock.\n 321:\t * * -ETIMEDOUT - Lock acquisition failed because of timeout.\n 322:\t *\n 323:\t * (queue tail, pending bit, lock value)\n 324:\t *\n 325:\t *              fast     :    slow                                  :    unlock\n 326:\t *                       :                                          :\n 327:\t * uncontended  (0,0,0) -:--\u003e (0,0,1) ------------------------------:--\u003e (*,*,0)\n 328:\t *                       :       | ^--------.------.             /  :\n 329:\t *                       :       v           \\      \\            |  :\n 330:\t * pending               :    (0,1,1) +--\u003e (0,1,0)   \\           |  :\n 331:\t *                       :       | ^--'              |           |  :\n 332:\t *                       :       v                   |           |  :\n 333:\t * uncontended           :    (n,x,y) +--\u003e (n,0,0) --'           |  :\n 334:\t *   queue               :       | ^--'                          |  :\n 335:\t *                       :       v                               |  :\n 336:\t * contended             :    (*,x,y) +--\u003e (*,0,0) ---\u003e (*,0,1) -'  :\n 337:\t *   queue               :         ^--'                             :\n 338:\t */\n 339:\tint __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val)\n 340:\t{\n 341:\t\tstruct mcs_spinlock *prev, *next, *node;\n 342:\t\tstruct rqspinlock_timeout ts;\n 343:\t\tint idx, ret = 0;\n 344:\t\tu32 old, tail;\n 345:\t\n 346:\t\tBUILD_BUG_ON(CONFIG_NR_CPUS \u003e= (1U \u003c\u003c _Q_TAIL_CPU_BITS));\n 347:\t\n 348:\t\tif (resilient_virt_spin_lock_enabled())\n 349:\t\t\treturn resilient_virt_spin_lock(lock);\n 350:\t\n 351:\t\tRES_INIT_TIMEOUT(ts);\n 352:\t\n 353:\t\t/*\n 354:\t\t * Wait for in-progress pending-\u003elocked hand-overs with a bounded\n 355:\t\t * number of spins so that we guarantee forward progress.\n 356:\t\t *\n 357:\t\t * 0,1,0 -\u003e 0,0,1\n 358:\t\t */\n 359:\t\tif (val == _Q_PENDING_VAL) {\n 360:\t\t\tint cnt = _Q_PENDING_LOOPS;\n 361:\t\t\tval = atomic_cond_read_relaxed(\u0026lock-\u003eval,\n 362:\t\t\t\t\t\t       (VAL != _Q_PENDING_VAL) || !cnt--);\n 363:\t\t}\n 364:\t\n 365:\t\t/*\n 366:\t\t * If we observe any contention; queue.\n 367:\t\t */\n 368:\t\tif (val \u0026 ~_Q_LOCKED_MASK)\n 369:\t\t\tgoto queue;\n 370:\t\n 371:\t\t/*\n 372:\t\t * trylock || pending\n 373:\t\t *\n 374:\t\t * 0,0,* -\u003e 0,1,* -\u003e 0,0,1 pending, trylock\n 375:\t\t */\n 376:\t\tval = queued_fetch_set_pending_acquire(lock);\n 377:\t\n 378:\t\t/*\n 379:\t\t * If we observe contention, there is a concurrent locker.\n 380:\t\t *\n 381:\t\t * Undo and queue; our setting of PENDING might have made the\n 382:\t\t * n,0,0 -\u003e 0,0,0 transition fail and it will now be waiting\n 383:\t\t * on @next to become !NULL.\n 384:\t\t */\n 385:\t\tif (unlikely(val \u0026 ~_Q_LOCKED_MASK)) {\n 386:\t\n 387:\t\t\t/* Undo PENDING if we set it. */\n 388:\t\t\tif (!(val \u0026 _Q_PENDING_MASK))\n 389:\t\t\t\tclear_pending(lock);\n"
}

gemini-3.1-pro-preview

							input: 5925
							output: 28
							thoughts: 67

Okay, let's see, my mental gears are turning...

**Analyzing `resilient_queued_spin_lock_slowpath`**

Right, so this `resilient_queued_spin_lock_slowpath` function is nestled inside the `#ifdef CONFIG_QUEUED_SPINLOCKS` block.  That immediately flags a configuration dependency, of course.  I need to figure out the scope of its relevance.  Is `CONFIG_QUEUED_SPINLOCKS` the *only* configuration option at play here, or are there any related ones? I should really confirm this; knowing all the relevant options helps me understand the complete picture of what's going on. The obvious places to look would be either `kernel/bpf/Kconfig` (since we are discussing the kernel) or maybe even `init/Kconfig` to see if `QUEUED_SPINLOCKS` is defined there. I need to dive into those Kconfig files and verify. That should give me a solid understanding of the context.

{
  "Expression": "config QUEUED_SPINLOCKS",
  "PathPrefix": ""
}

{
  "Output": "kernel/Kconfig.locks=239=config ARCH_USE_QUEUED_SPINLOCKS\n--\nkernel/Kconfig.locks-241-\nkernel/Kconfig.locks:242:config QUEUED_SPINLOCKS\nkernel/Kconfig.locks-243-\tdef_bool y if ARCH_USE_QUEUED_SPINLOCKS\n"
}

gemini-3.1-pro-preview

							input: 6337
							output: 38
							thoughts: 83

**Analyzing Spinlock Configuration and BPF Integration**

Okay, so I'm digging into how spinlocks are configured in this kernel build. It looks like `QUEUED_SPINLOCKS` is enabled by default, *provided* `ARCH_USE_QUEUED_SPINLOCKS` is also set. That's the typical behavior I'd expect. Now, here's where it gets interesting. I see that `kernel/bpf/rqspinlock.c` is being compiled *only* when `CONFIG_BPF_SYSCALL` is enabled. That suggests a direct relationship between BPF (Berkeley Packet Filter) and some specific queued spinlock implementations. I need to understand that. Let me jump into the code and focus on `kernel/bpf/rqspinlock.c`, specifically around line 572. I'm guessing that's where the critical BPF-related spinlock interaction is defined.

{
  "File": "kernel/bpf/rqspinlock.c",
  "FirstLine": 550,
  "LineCount": 100
}

{
  "Contents": " 550:\t\t\t\tprefetchw(next);\n 551:\t\t}\n 552:\t\n 553:\t\t/*\n 554:\t\t * we're at the head of the waitqueue, wait for the owner \u0026 pending to\n 555:\t\t * go away.\n 556:\t\t *\n 557:\t\t * *,x,y -\u003e *,0,0\n 558:\t\t *\n 559:\t\t * this wait loop must use a load-acquire such that we match the\n 560:\t\t * store-release that clears the locked bit and create lock\n 561:\t\t * sequentiality; this is because the set_locked() function below\n 562:\t\t * does not imply a full barrier.\n 563:\t\t *\n 564:\t\t * We use RES_DEF_TIMEOUT * 2 as the duration, as RES_DEF_TIMEOUT is\n 565:\t\t * meant to span maximum allowed time per critical section, and we may\n 566:\t\t * have both the owner of the lock and the pending bit waiter ahead of\n 567:\t\t * us.\n 568:\t\t */\n 569:\t\tRES_RESET_TIMEOUT(ts, RES_DEF_TIMEOUT * 2);\n 570:\t\tval = res_atomic_cond_read_acquire(\u0026lock-\u003eval, !(VAL \u0026 _Q_LOCKED_PENDING_MASK) ||\n 571:\t\t\t\t\t\t   RES_CHECK_TIMEOUT(ts, ret, _Q_LOCKED_PENDING_MASK));\n 572:\t\n 573:\t\t/* Disable queue destruction when we detect deadlocks. */\n 574:\t\tif (ret == -EDEADLK) {\n 575:\t\t\tif (!try_cmpxchg_tail(lock, tail, 0)) {\n 576:\t\t\t\tnext = smp_cond_load_relaxed(\u0026node-\u003enext, (VAL));\n 577:\t\t\t\tarch_mcs_spin_unlock_contended(\u0026next-\u003elocked);\n 578:\t\t\t}\n 579:\t\t\tgoto err_release_node;\n 580:\t\t}\n 581:\t\n 582:\twaitq_timeout:\n 583:\t\tif (ret) {\n 584:\t\t\t/*\n 585:\t\t\t * If the tail is still pointing to us, then we are the final waiter,\n 586:\t\t\t * and are responsible for resetting the tail back to 0. Otherwise, if\n 587:\t\t\t * the cmpxchg operation fails, we signal the next waiter to take exit\n 588:\t\t\t * and try the same. For a waiter with tail node 'n':\n 589:\t\t\t *\n 590:\t\t\t * n,*,* -\u003e 0,*,*\n 591:\t\t\t *\n 592:\t\t\t * When performing cmpxchg for the whole word (NR_CPUS \u003e 16k), it is\n 593:\t\t\t * possible locked/pending bits keep changing and we see failures even\n 594:\t\t\t * when we remain the head of wait queue. However, eventually,\n 595:\t\t\t * pending bit owner will unset the pending bit, and new waiters\n 596:\t\t\t * will queue behind us. This will leave the lock owner in\n 597:\t\t\t * charge, and it will eventually either set locked bit to 0, or\n 598:\t\t\t * leave it as 1, allowing us to make progress.\n 599:\t\t\t *\n 600:\t\t\t * We terminate the whole wait queue for two reasons. Firstly,\n 601:\t\t\t * we eschew per-waiter timeouts with one applied at the head of\n 602:\t\t\t * the wait queue.  This allows everyone to break out faster\n 603:\t\t\t * once we've seen the owner / pending waiter not responding for\n 604:\t\t\t * the timeout duration from the head.  Secondly, it avoids\n 605:\t\t\t * complicated synchronization, because when not leaving in FIFO\n 606:\t\t\t * order, prev's next pointer needs to be fixed up etc.\n 607:\t\t\t */\n 608:\t\t\tif (!try_cmpxchg_tail(lock, tail, 0)) {\n 609:\t\t\t\tnext = smp_cond_load_relaxed(\u0026node-\u003enext, VAL);\n 610:\t\t\t\tWRITE_ONCE(next-\u003elocked, RES_TIMEOUT_VAL);\n 611:\t\t\t}\n 612:\t\t\tlockevent_inc(rqspinlock_lock_timeout);\n 613:\t\t\tgoto err_release_node;\n 614:\t\t}\n 615:\t\n 616:\t\t/*\n 617:\t\t * claim the lock:\n 618:\t\t *\n 619:\t\t * n,0,0 -\u003e 0,0,1 : lock, uncontended\n 620:\t\t * *,*,0 -\u003e *,*,1 : lock, contended\n 621:\t\t *\n 622:\t\t * If the queue head is the only one in the queue (lock value == tail)\n 623:\t\t * and nobody is pending, clear the tail code and grab the lock.\n 624:\t\t * Otherwise, we only need to grab the lock.\n 625:\t\t */\n 626:\t\n 627:\t\t/*\n 628:\t\t * Note: at this point: (val \u0026 _Q_PENDING_MASK) == 0, because of the\n 629:\t\t *       above wait condition, therefore any concurrent setting of\n 630:\t\t *       PENDING will make the uncontended transition fail.\n 631:\t\t */\n 632:\t\tif ((val \u0026 _Q_TAIL_MASK) == tail) {\n 633:\t\t\tif (atomic_try_cmpxchg_relaxed(\u0026lock-\u003eval, \u0026val, _Q_LOCKED_VAL))\n 634:\t\t\t\tgoto release; /* No contention */\n 635:\t\t}\n 636:\t\n 637:\t\t/*\n 638:\t\t * Either somebody is queued behind us or _Q_PENDING_VAL got set\n 639:\t\t * which will then detect the remaining tail and queue behind us\n 640:\t\t * ensuring we'll see a @next.\n 641:\t\t */\n 642:\t\tset_locked(lock);\n 643:\t\n 644:\t\t/*\n 645:\t\t * contended path; wait for next if not observed yet, release.\n 646:\t\t */\n 647:\t\tif (!next)\n 648:\t\t\tnext = smp_cond_load_relaxed(\u0026node-\u003enext, (VAL));\n 649:\t\n"
}

gemini-3.1-pro-preview

							input: 8300
							output: 27
							thoughts: 193

**Fuzzing the Resilient Queued Spin Lock Slow Path**

Okay, so I've found a promising target: the `resilient_queued_spin_lock_slowpath` function. It's right there, exported, and deeply embedded within the core BPF locking mechanism. It's definitely functional code and well worth a fuzzing campaign.

My initial thoughts on the configs needed were a little muddled. I needed to ensure `BPF_SYSCALL` is enabled, obviously. I also thought `QUEUED_SPINLOCKS` was a user-settable option. But after a second look, I realize `QUEUED_SPINLOCKS` is actually a `def_bool`, tied to `ARCH_USE_QUEUED_SPINLOCKS`. In other words, architecture-dependent. So, listing it might not be relevant, and listing `BPF_SYSCALL` is the crucial configuration.

Hang on... what about `CONFIG_QUEUED_SPINLOCKS`? Ah, right, that's *also* not a direct user config, it is selected by the architecture. So the *only* thing I really need to check is `BPF_SYSCALL`.

Now, before I launch into fuzzing, let me quickly double-check that there aren't any other related configs I'm missing...

{
  "Expression": "config BPF_SYSCALL",
  "PathPrefix": ""
}

{
  "Output": "kernel/bpf/Kconfig=25=menu \"BPF subsystem\"\nkernel/bpf/Kconfig-26-\nkernel/bpf/Kconfig:27:config BPF_SYSCALL\nkernel/bpf/Kconfig-28-\tbool \"Enable bpf() system call\"\n"
}

gemini-3.1-pro-preview

							input: 8893
							output: 31
							thoughts: 23

Okay, here's my summary, presented as a stream of thought:

**Checking the Callers of `resilient_queued_spin_lock_slowpath`**

Right, let's see. I need to understand where this `resilient_queued_spin_lock_slowpath` function is being used. It's a key part of the locking mechanism, and understanding its call sites is critical for analyzing performance, debugging concurrency issues, and maybe even identifying potential bottlenecks or areas for optimization. I'll need to identify *all* the places this slowpath is entered to get a handle on what might be going on, I need to know the context this is happening in. I'll probably start with a grep or a similar search, I should be able to track down its callers pretty quickly. Hopefully, the naming is clear and I can narrow down the search. This will give me a clear picture of how frequently the slow path is triggered and under what circumstances. The goal here is a full dependency graph!

{
  "Expression": "resilient_queued_spin_lock_slowpath",
  "PathPrefix": ""
}

{
  "Output": "include/asm-generic/rqspinlock.h=40=extern int resilient_tas_spin_lock(rqspinlock_t *lock);\ninclude/asm-generic/rqspinlock.h-41-#ifdef CONFIG_QUEUED_SPINLOCKS\ninclude/asm-generic/rqspinlock.h:42:extern int resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val);\ninclude/asm-generic/rqspinlock.h-43-#endif\n--\ninclude/asm-generic/rqspinlock.h=169=static __always_inline int res_spin_lock(rqspinlock_t *lock)\n--\ninclude/asm-generic/rqspinlock.h-188-\t\treturn 0;\ninclude/asm-generic/rqspinlock.h:189:\treturn resilient_queued_spin_lock_slowpath(lock, val);\ninclude/asm-generic/rqspinlock.h-190-}\n--\nkernel/bpf/rqspinlock.c=261=int __lockfunc resilient_tas_spin_lock(rqspinlock_t *lock)\n--\nkernel/bpf/rqspinlock.c-269-\t * deadlock detection entry when queued spinlocks are disabled, or from\nkernel/bpf/rqspinlock.c:270:\t * resilient_queued_spin_lock_slowpath after grabbing the deadlock\nkernel/bpf/rqspinlock.c-271-\t * detection entry. No need to obtain it here.\n--\nkernel/bpf/rqspinlock.c=305=static DEFINE_PER_CPU_ALIGNED(struct qnode, rqnodes[_Q_MAX_NODES]);\n--\nkernel/bpf/rqspinlock.c-313-/**\nkernel/bpf/rqspinlock.c:314: * resilient_queued_spin_lock_slowpath - acquire the queued spinlock\nkernel/bpf/rqspinlock.c-315- * @lock: Pointer to queued spinlock structure\n--\nkernel/bpf/rqspinlock.c-338- */\nkernel/bpf/rqspinlock.c:339:int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val)\nkernel/bpf/rqspinlock.c-340-{\n--\nkernel/bpf/rqspinlock.c-666-}\nkernel/bpf/rqspinlock.c:667:EXPORT_SYMBOL_GPL(resilient_queued_spin_lock_slowpath);\nkernel/bpf/rqspinlock.c-668-\n"
}

gemini-3.1-pro-preview

							input: 9776
							output: 25
							thoughts: 40

Okay, here's my take on those thoughts, framed as an expert's internal monologue:

**Investigating the `res_spin_lock` Usage**

Right, so this is called from `res_spin_lock` within `include/asm-generic/rqspinlock.h`. The `rqspinlock.h` header file suggests we're dealing with resource-aware spinlocks, probably something related to runqueue management. That tells me a lot already, actually. Now, I need to understand the *context*. Knowing where `res_spin_lock` is used is absolutely critical here. I need to trace its callers. I'll need to use my tools - grep, `cscope`... whatever's appropriate for this codebase - to quickly identify all the call sites of `res_spin_lock`. I need to understand *why* these locks are being acquired and what data they're protecting to get the bigger picture. Are these runqueue locks, or something else entirely? A quick check should tell me all I need to know about the function calls to `res_spin_lock`, and what context it is called in. From there, I can figure out the problem.

{
  "Expression": "res_spin_lock",
  "PathPrefix": ""
}

{
  "Output": "\nFull output is too long, showing 500 out of 865 lines.\nUse more precise expression if possible.\n\ninclude/asm-generic/rqspinlock.h=19=struct rqspinlock {\n--\ninclude/asm-generic/rqspinlock.h-28- */\ninclude/asm-generic/rqspinlock.h:29:struct bpf_res_spin_lock {\ninclude/asm-generic/rqspinlock.h-30-\tu32 val;\n--\ninclude/asm-generic/rqspinlock.h=110=static __always_inline void release_held_lock_entry(void)\n--\ninclude/asm-generic/rqspinlock.h-160-/**\ninclude/asm-generic/rqspinlock.h:161: * res_spin_lock - acquire a queued spinlock\ninclude/asm-generic/rqspinlock.h-162- * @lock: Pointer to queued spinlock structure\n--\ninclude/asm-generic/rqspinlock.h-168- */\ninclude/asm-generic/rqspinlock.h:169:static __always_inline int res_spin_lock(rqspinlock_t *lock)\ninclude/asm-generic/rqspinlock.h-170-{\n--\ninclude/asm-generic/rqspinlock.h-180-\t * \u003cNMI\u003e\ninclude/asm-generic/rqspinlock.h:181:\t * res_spin_lock(A) --\u003e missed AA, leads to timeout\ninclude/asm-generic/rqspinlock.h-182-\t * \u003c/NMI\u003e\n--\ninclude/asm-generic/rqspinlock.h-193-\ninclude/asm-generic/rqspinlock.h:194:#define res_spin_lock(lock) ({ grab_held_lock_entry(lock); resilient_tas_spin_lock(lock); })\ninclude/asm-generic/rqspinlock.h-195-\n--\ninclude/asm-generic/rqspinlock.h=198=static __always_inline void res_spin_unlock(rqspinlock_t *lock)\n--\ninclude/asm-generic/rqspinlock.h-213-\t * \u003cNMI\u003e\ninclude/asm-generic/rqspinlock.h:214:\t * res_spin_lock(A) --\u003e missed AA, leads to timeout\ninclude/asm-generic/rqspinlock.h-215-\t * \u003c/NMI\u003e\n--\ninclude/asm-generic/rqspinlock.h-224-#ifdef CONFIG_QUEUED_SPINLOCKS\ninclude/asm-generic/rqspinlock.h:225:#define raw_res_spin_lock_init(lock) ({ *(lock) = (rqspinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; })\ninclude/asm-generic/rqspinlock.h-226-#else\ninclude/asm-generic/rqspinlock.h:227:#define raw_res_spin_lock_init(lock) ({ *(lock) = (rqspinlock_t){0}; })\ninclude/asm-generic/rqspinlock.h-228-#endif\ninclude/asm-generic/rqspinlock.h-229-\ninclude/asm-generic/rqspinlock.h:230:#define raw_res_spin_lock(lock)                    \\\ninclude/asm-generic/rqspinlock.h-231-\t({                                         \\\n--\ninclude/asm-generic/rqspinlock.h-233-\t\tpreempt_disable();                 \\\ninclude/asm-generic/rqspinlock.h:234:\t\t__ret = res_spin_lock(lock);\t   \\\ninclude/asm-generic/rqspinlock.h-235-\t\tif (__ret)                         \\\n--\ninclude/asm-generic/rqspinlock.h-241-\ninclude/asm-generic/rqspinlock.h:242:#define raw_res_spin_lock_irqsave(lock, flags)    \\\ninclude/asm-generic/rqspinlock.h-243-\t({                                        \\\n--\ninclude/asm-generic/rqspinlock.h-246-\t\tpreempt_disable();                \\\ninclude/asm-generic/rqspinlock.h:247:\t\t__ret = res_spin_lock(lock);      \\\ninclude/asm-generic/rqspinlock.h-248-\t\tif (__ret) {                      \\\n--\ninclude/linux/bpf.h=261=struct btf_record {\n--\ninclude/linux/bpf.h-264-\tint spin_lock_off;\ninclude/linux/bpf.h:265:\tint res_spin_lock_off;\ninclude/linux/bpf.h-266-\tint timer_off;\n--\ninclude/linux/bpf.h=346=static inline const char *btf_field_type_name(enum btf_field_type type)\n--\ninclude/linux/bpf.h-351-\tcase BPF_RES_SPIN_LOCK:\ninclude/linux/bpf.h:352:\t\treturn \"bpf_res_spin_lock\";\ninclude/linux/bpf.h-353-\tcase BPF_TIMER:\n--\ninclude/linux/bpf.h=388=static inline u32 btf_field_type_size(enum btf_field_type type)\n--\ninclude/linux/bpf.h-393-\tcase BPF_RES_SPIN_LOCK:\ninclude/linux/bpf.h:394:\t\treturn sizeof(struct bpf_res_spin_lock);\ninclude/linux/bpf.h-395-\tcase BPF_TIMER:\n--\ninclude/linux/bpf.h=422=static inline u32 btf_field_type_align(enum btf_field_type type)\n--\ninclude/linux/bpf.h-427-\tcase BPF_RES_SPIN_LOCK:\ninclude/linux/bpf.h:428:\t\treturn __alignof__(struct bpf_res_spin_lock);\ninclude/linux/bpf.h-429-\tcase BPF_TIMER:\n--\nkernel/bpf/arena.c=262=static struct bpf_map *arena_map_alloc(union bpf_attr *attr)\n--\nkernel/bpf/arena.c-320-\tmutex_init(\u0026arena-\u003ezap_mutex);\nkernel/bpf/arena.c:321:\traw_res_spin_lock_init(\u0026arena-\u003espinlock);\nkernel/bpf/arena.c-322-\terr = populate_pgtable_except_pte(arena);\n--\nkernel/bpf/arena.c=473=static vm_fault_t arena_vm_fault(struct vm_fault *vmf)\n--\nkernel/bpf/arena.c-485-\nkernel/bpf/arena.c:486:\tif (raw_res_spin_lock_irqsave(\u0026arena-\u003espinlock, flags))\nkernel/bpf/arena.c-487-\t\t/* Make a reasonable effort to address impossible case */\n--\nkernel/bpf/arena.c=659=static long arena_alloc_pages(struct bpf_arena *arena, long uaddr, long page_cnt, int node_id,\n--\nkernel/bpf/arena.c-701-\nkernel/bpf/arena.c:702:\tif (raw_res_spin_lock_irqsave(\u0026arena-\u003espinlock, flags))\nkernel/bpf/arena.c-703-\t\tgoto out_free_pages;\n--\nkernel/bpf/arena.c=838=static void arena_free_pages(struct bpf_arena *arena, long uaddr, long page_cnt, bool sleepable)\n--\nkernel/bpf/arena.c-866-\nkernel/bpf/arena.c:867:\tret = raw_res_spin_lock_irqsave(\u0026arena-\u003espinlock, flags);\nkernel/bpf/arena.c-868-\n--\nkernel/bpf/arena.c=928=static int arena_reserve_pages(struct bpf_arena *arena, long uaddr, u32 page_cnt)\n--\nkernel/bpf/arena.c-942-\nkernel/bpf/arena.c:943:\tif (raw_res_spin_lock_irqsave(\u0026arena-\u003espinlock, flags))\nkernel/bpf/arena.c-944-\t\treturn -EBUSY;\n--\nkernel/bpf/arena.c=962=static void arena_free_worker(struct work_struct *work)\n--\nkernel/bpf/arena.c-975-\nkernel/bpf/arena.c:976:\tif (raw_res_spin_lock_irqsave(\u0026arena-\u003espinlock, flags)) {\nkernel/bpf/arena.c-977-\t\tschedule_work(work);\n--\nkernel/bpf/bpf_local_storage.c=243=static int bpf_selem_unlink_map(struct bpf_local_storage_elem *selem)\n--\nkernel/bpf/bpf_local_storage.c-254-\tb = select_bucket(smap, local_storage);\nkernel/bpf/bpf_local_storage.c:255:\terr = raw_res_spin_lock_irqsave(\u0026b-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-256-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=270=int bpf_selem_link_map(struct bpf_local_storage_map *smap,\n--\nkernel/bpf/bpf_local_storage.c-279-\nkernel/bpf/bpf_local_storage.c:280:\terr = raw_res_spin_lock_irqsave(\u0026b-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-281-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=300=int bpf_selem_unlink(struct bpf_local_storage_elem *selem)\n--\nkernel/bpf/bpf_local_storage.c-317-\nkernel/bpf/bpf_local_storage.c:318:\terr = raw_res_spin_lock_irqsave(\u0026local_storage-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-319-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=350=static void bpf_selem_unlink_nofail(struct bpf_local_storage_elem *selem,\n--\nkernel/bpf/bpf_local_storage.c-363-\t\tb = b ? : select_bucket(smap, local_storage);\nkernel/bpf/bpf_local_storage.c:364:\t\terr = raw_res_spin_lock_irqsave(\u0026b-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-365-\t\tif (!err) {\n--\nkernel/bpf/bpf_local_storage.c-384-\t\t * destroy(selem1) will be able to free the special field associated\nkernel/bpf/bpf_local_storage.c:385:\t\t * with selem1 as raw_res_spin_lock_irqsave() returns -ETIMEDOUT.\nkernel/bpf/bpf_local_storage.c-386-\t\t */\n--\nkernel/bpf/bpf_local_storage.c-392-\tif (local_storage) {\nkernel/bpf/bpf_local_storage.c:393:\t\terr = raw_res_spin_lock_irqsave(\u0026local_storage-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-394-\t\tif (!err) {\n--\nkernel/bpf/bpf_local_storage.c=441=void __bpf_local_storage_insert_cache(struct bpf_local_storage *local_storage,\n--\nkernel/bpf/bpf_local_storage.c-452-\t */\nkernel/bpf/bpf_local_storage.c:453:\terr = raw_res_spin_lock_irqsave(\u0026local_storage-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-454-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=476=int bpf_local_storage_alloc(void *owner,\n--\nkernel/bpf/bpf_local_storage.c-497-\tINIT_HLIST_HEAD(\u0026storage-\u003elist);\nkernel/bpf/bpf_local_storage.c:498:\traw_res_spin_lock_init(\u0026storage-\u003elock);\nkernel/bpf/bpf_local_storage.c-499-\tstorage-\u003eowner = owner;\n--\nkernel/bpf/bpf_local_storage.c-505-\tb = select_bucket(smap, storage);\nkernel/bpf/bpf_local_storage.c:506:\terr = raw_res_spin_lock_irqsave(\u0026b-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-507-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=547=bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap,\n--\nkernel/bpf/bpf_local_storage.c-610-\nkernel/bpf/bpf_local_storage.c:611:\terr = raw_res_spin_lock_irqsave(\u0026local_storage-\u003elock, flags);\nkernel/bpf/bpf_local_storage.c-612-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c-639-\nkernel/bpf/bpf_local_storage.c:640:\terr = raw_res_spin_lock_irqsave(\u0026b-\u003elock, b_flags);\nkernel/bpf/bpf_local_storage.c-641-\tif (err)\n--\nkernel/bpf/bpf_local_storage.c=773=bpf_local_storage_map_alloc(union bpf_attr *attr,\n--\nkernel/bpf/bpf_local_storage.c-799-\t\tINIT_HLIST_HEAD(\u0026smap-\u003ebuckets[i].list);\nkernel/bpf/bpf_local_storage.c:800:\t\traw_res_spin_lock_init(\u0026smap-\u003ebuckets[i].lock);\nkernel/bpf/bpf_local_storage.c-801-\t}\n--\nkernel/bpf/bpf_lru_list.c=296=static void bpf_lru_list_push_free(struct bpf_lru_list *l,\n--\nkernel/bpf/bpf_lru_list.c-303-\nkernel/bpf/bpf_lru_list.c:304:\tif (raw_res_spin_lock_irqsave(\u0026l-\u003elock, flags)) {\nkernel/bpf/bpf_lru_list.c-305-\t\tWRITE_ONCE(node-\u003epending_free, 1);\n--\nkernel/bpf/bpf_lru_list.c=312=static void bpf_lru_list_pop_free_to_local(struct bpf_lru *lru,\n--\nkernel/bpf/bpf_lru_list.c-319-\nkernel/bpf/bpf_lru_list.c:320:\tif (raw_res_spin_lock(\u0026l-\u003elock))\nkernel/bpf/bpf_lru_list.c-321-\t\treturn;\n--\nkernel/bpf/bpf_lru_list.c=403=static struct bpf_lru_node *bpf_percpu_lru_pop_free(struct bpf_lru *lru,\n--\nkernel/bpf/bpf_lru_list.c-413-\nkernel/bpf/bpf_lru_list.c:414:\tif (raw_res_spin_lock_irqsave(\u0026l-\u003elock, flags))\nkernel/bpf/bpf_lru_list.c-415-\t\treturn NULL;\n--\nkernel/bpf/bpf_lru_list.c=436=static struct bpf_lru_node *bpf_common_lru_pop_free(struct bpf_lru *lru,\n--\nkernel/bpf/bpf_lru_list.c-447-\nkernel/bpf/bpf_lru_list.c:448:\tif (raw_res_spin_lock_irqsave(\u0026loc_l-\u003elock, flags))\nkernel/bpf/bpf_lru_list.c-449-\t\treturn NULL;\n--\nkernel/bpf/bpf_lru_list.c-482-\nkernel/bpf/bpf_lru_list.c:483:\t\tif (!raw_res_spin_lock_irqsave(\u0026steal_loc_l-\u003elock, flags)) {\nkernel/bpf/bpf_lru_list.c-484-\t\t\tnode = __local_list_pop_free(steal_loc_l);\n--\nkernel/bpf/bpf_lru_list.c-497-\nkernel/bpf/bpf_lru_list.c:498:\tif (raw_res_spin_lock_irqsave(\u0026loc_l-\u003elock, flags)) {\nkernel/bpf/bpf_lru_list.c-499-\t\t/*\n--\nkernel/bpf/bpf_lru_list.c=525=static void bpf_common_lru_push_free(struct bpf_lru *lru,\n--\nkernel/bpf/bpf_lru_list.c-539-\nkernel/bpf/bpf_lru_list.c:540:\t\tif (raw_res_spin_lock_irqsave(\u0026loc_l-\u003elock, flags)) {\nkernel/bpf/bpf_lru_list.c-541-\t\t\tWRITE_ONCE(node-\u003epending_free, 1);\n--\nkernel/bpf/bpf_lru_list.c=565=static void bpf_percpu_lru_push_free(struct bpf_lru *lru,\n--\nkernel/bpf/bpf_lru_list.c-572-\nkernel/bpf/bpf_lru_list.c:573:\tif (raw_res_spin_lock_irqsave(\u0026l-\u003elock, flags)) {\nkernel/bpf/bpf_lru_list.c-574-\t\tWRITE_ONCE(node-\u003epending_free, 1);\n--\nkernel/bpf/bpf_lru_list.c=656=static void bpf_lru_locallist_init(struct bpf_lru_locallist *loc_l, int cpu)\n--\nkernel/bpf/bpf_lru_list.c-662-\nkernel/bpf/bpf_lru_list.c:663:\traw_res_spin_lock_init(\u0026loc_l-\u003elock);\nkernel/bpf/bpf_lru_list.c-664-}\n--\nkernel/bpf/bpf_lru_list.c=666=static void bpf_lru_list_init(struct bpf_lru_list *l)\n--\nkernel/bpf/bpf_lru_list.c-677-\nkernel/bpf/bpf_lru_list.c:678:\traw_res_spin_lock_init(\u0026l-\u003elock);\nkernel/bpf/bpf_lru_list.c-679-}\n--\nkernel/bpf/btf.c=3655=static int btf_get_field_type(const struct btf *btf, const struct btf_type *var_type,\n--\nkernel/bpf/btf.c-3663-\t\t{ BPF_SPIN_LOCK, \"bpf_spin_lock\", true },\nkernel/bpf/btf.c:3664:\t\t{ BPF_RES_SPIN_LOCK, \"bpf_res_spin_lock\", true },\nkernel/bpf/btf.c-3665-\t\t{ BPF_TIMER, \"bpf_timer\", true },\n--\nkernel/bpf/btf.c=4118=struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,\n--\nkernel/bpf/btf.c-4140-\trec-\u003espin_lock_off = -EINVAL;\nkernel/bpf/btf.c:4141:\trec-\u003eres_spin_lock_off = -EINVAL;\nkernel/bpf/btf.c-4142-\trec-\u003etimer_off = -EINVAL;\n--\nkernel/bpf/btf.c-4172-\t\t\t/* Cache offset for faster lookup at runtime */\nkernel/bpf/btf.c:4173:\t\t\trec-\u003eres_spin_lock_off = rec-\u003efields[i].offset;\nkernel/bpf/btf.c-4174-\t\t\tbreak;\n--\nkernel/bpf/btf.c-4221-\nkernel/bpf/btf.c:4222:\tif (rec-\u003espin_lock_off \u003e= 0 \u0026\u0026 rec-\u003eres_spin_lock_off \u003e= 0) {\nkernel/bpf/btf.c-4223-\t\tret = -EINVAL;\n--\nkernel/bpf/btf.c-4229-\t     btf_record_has_field(rec, BPF_RB_ROOT)) \u0026\u0026\nkernel/bpf/btf.c:4230:\t\t (rec-\u003espin_lock_off \u003c 0 \u0026\u0026 rec-\u003eres_spin_lock_off \u003c 0)) {\nkernel/bpf/btf.c-4231-\t\tret = -EINVAL;\n--\nkernel/bpf/hashtab.c=139=static void htab_init_buckets(struct bpf_htab *htab)\n--\nkernel/bpf/hashtab.c-144-\t\tINIT_HLIST_NULLS_HEAD(\u0026htab-\u003ebuckets[i].head, i);\nkernel/bpf/hashtab.c:145:\t\traw_res_spin_lock_init(\u0026htab-\u003ebuckets[i].raw_lock);\nkernel/bpf/hashtab.c-146-\t\tcond_resched();\n--\nkernel/bpf/hashtab.c=150=static inline int htab_lock_bucket(struct bucket *b, unsigned long *pflags)\n--\nkernel/bpf/hashtab.c-154-\nkernel/bpf/hashtab.c:155:\tret = raw_res_spin_lock_irqsave(\u0026b-\u003eraw_lock, flags);\nkernel/bpf/hashtab.c-156-\tif (ret)\n--\nkernel/bpf/lpm_trie.c=322=static long trie_update_elem(struct bpf_map *map,\n--\nkernel/bpf/lpm_trie.c-345-\nkernel/bpf/lpm_trie.c:346:\tret = raw_res_spin_lock_irqsave(\u0026trie-\u003elock, irq_flags);\nkernel/bpf/lpm_trie.c-347-\tif (ret)\n--\nkernel/bpf/lpm_trie.c=457=static long trie_delete_elem(struct bpf_map *map, void *_key)\n--\nkernel/bpf/lpm_trie.c-471-\nkernel/bpf/lpm_trie.c:472:\tret = raw_res_spin_lock_irqsave(\u0026trie-\u003elock, irq_flags);\nkernel/bpf/lpm_trie.c-473-\tif (ret)\n--\nkernel/bpf/lpm_trie.c=571=static struct bpf_map *trie_alloc(union bpf_attr *attr)\n--\nkernel/bpf/lpm_trie.c-597-\nkernel/bpf/lpm_trie.c:598:\traw_res_spin_lock_init(\u0026trie-\u003elock);\nkernel/bpf/lpm_trie.c-599-\n--\nkernel/bpf/percpu_freelist.c=6=int pcpu_freelist_init(struct pcpu_freelist *s)\n--\nkernel/bpf/percpu_freelist.c-16-\nkernel/bpf/percpu_freelist.c:17:\t\traw_res_spin_lock_init(\u0026head-\u003elock);\nkernel/bpf/percpu_freelist.c-18-\t\thead-\u003efirst = NULL;\n--\nkernel/bpf/percpu_freelist.c=35=static inline bool ___pcpu_freelist_push(struct pcpu_freelist_head *head,\n--\nkernel/bpf/percpu_freelist.c-37-{\nkernel/bpf/percpu_freelist.c:38:\tif (raw_res_spin_lock(\u0026head-\u003elock))\nkernel/bpf/percpu_freelist.c-39-\t\treturn false;\n--\nkernel/bpf/percpu_freelist.c=45=void __pcpu_freelist_push(struct pcpu_freelist *s,\n--\nkernel/bpf/percpu_freelist.c-58-\t\t\thead = per_cpu_ptr(s-\u003efreelist, cpu);\nkernel/bpf/percpu_freelist.c:59:\t\t\tif (raw_res_spin_lock(\u0026head-\u003elock))\nkernel/bpf/percpu_freelist.c-60-\t\t\t\tcontinue;\n--\nkernel/bpf/percpu_freelist.c=100=static struct pcpu_freelist_node *___pcpu_freelist_pop(struct pcpu_freelist *s)\n--\nkernel/bpf/percpu_freelist.c-109-\t\t\tcontinue;\nkernel/bpf/percpu_freelist.c:110:\t\tif (raw_res_spin_lock(\u0026head-\u003elock))\nkernel/bpf/percpu_freelist.c-111-\t\t\tcontinue;\n--\nkernel/bpf/queue_stack_maps.c=65=static struct bpf_map *queue_stack_map_alloc(union bpf_attr *attr)\n--\nkernel/bpf/queue_stack_maps.c-81-\nkernel/bpf/queue_stack_maps.c:82:\traw_res_spin_lock_init(\u0026qs-\u003elock);\nkernel/bpf/queue_stack_maps.c-83-\n--\nkernel/bpf/queue_stack_maps.c=95=static long __queue_map_get(struct bpf_map *map, void *value, bool delete)\n--\nkernel/bpf/queue_stack_maps.c-101-\nkernel/bpf/queue_stack_maps.c:102:\tif (raw_res_spin_lock_irqsave(\u0026qs-\u003elock, flags))\nkernel/bpf/queue_stack_maps.c-103-\t\treturn -EBUSY;\n--\nkernel/bpf/queue_stack_maps.c=125=static long __stack_map_get(struct bpf_map *map, void *value, bool delete)\n--\nkernel/bpf/queue_stack_maps.c-132-\nkernel/bpf/queue_stack_maps.c:133:\tif (raw_res_spin_lock_irqsave(\u0026qs-\u003elock, flags))\nkernel/bpf/queue_stack_maps.c-134-\t\treturn -EBUSY;\n--\nkernel/bpf/queue_stack_maps.c=182=static long queue_stack_map_push_elem(struct bpf_map *map, void *value,\n--\nkernel/bpf/queue_stack_maps.c-198-\nkernel/bpf/queue_stack_maps.c:199:\tif (raw_res_spin_lock_irqsave(\u0026qs-\u003elock, irq_flags))\nkernel/bpf/queue_stack_maps.c-200-\t\treturn -EBUSY;\n--\nkernel/bpf/ringbuf.c=172=static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node, bool overwrite_mode)\n--\nkernel/bpf/ringbuf.c-179-\nkernel/bpf/ringbuf.c:180:\traw_res_spin_lock_init(\u0026rb-\u003espinlock);\nkernel/bpf/ringbuf.c-181-\tatomic_set(\u0026rb-\u003ebusy, 0);\n--\nkernel/bpf/ringbuf.c=463=static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size)\n--\nkernel/bpf/ringbuf.c-477-\nkernel/bpf/ringbuf.c:478:\tif (raw_res_spin_lock_irqsave(\u0026rb-\u003espinlock, flags))\nkernel/bpf/ringbuf.c-479-\t\treturn NULL;\n--\nkernel/bpf/rqspinlock.c=261=int __lockfunc resilient_tas_spin_lock(rqspinlock_t *lock)\n--\nkernel/bpf/rqspinlock.c-267-\t/*\nkernel/bpf/rqspinlock.c:268:\t * We are either called directly from res_spin_lock after grabbing the\nkernel/bpf/rqspinlock.c-269-\t * deadlock detection entry when queued spinlocks are disabled, or from\n--\nkernel/bpf/rqspinlock.c=673=static void bpf_prog_report_rqspinlock_violation(const char *str, void *lock, bool irqsave)\n--\nkernel/bpf/rqspinlock.c-682-\tbpf_stream_stage(ss, prog, BPF_STDERR, ({\nkernel/bpf/rqspinlock.c:683:\t\tbpf_stream_printk(ss, \"ERROR: %s for bpf_res_spin_lock%s\\n\", str, irqsave ? \"_irqsave\" : \"\");\nkernel/bpf/rqspinlock.c-684-\t\tbpf_stream_printk(ss, \"Attempted lock   = 0x%px\\n\", lock);\n--\nkernel/bpf/rqspinlock.c-693-\nkernel/bpf/rqspinlock.c:694:__bpf_kfunc int bpf_res_spin_lock(struct bpf_res_spin_lock *lock)\nkernel/bpf/rqspinlock.c-695-{\n--\nkernel/bpf/rqspinlock.c-697-\nkernel/bpf/rqspinlock.c:698:\tBUILD_BUG_ON(sizeof(rqspinlock_t) != sizeof(struct bpf_res_spin_lock));\nkernel/bpf/rqspinlock.c-699-\nkernel/bpf/rqspinlock.c-700-\tpreempt_disable();\nkernel/bpf/rqspinlock.c:701:\tret = res_spin_lock((rqspinlock_t *)lock);\nkernel/bpf/rqspinlock.c-702-\tif (unlikely(ret)) {\n--\nkernel/bpf/rqspinlock.c-709-\nkernel/bpf/rqspinlock.c:710:__bpf_kfunc void bpf_res_spin_unlock(struct bpf_res_spin_lock *lock)\nkernel/bpf/rqspinlock.c-711-{\n--\nkernel/bpf/rqspinlock.c-715-\nkernel/bpf/rqspinlock.c:716:__bpf_kfunc int bpf_res_spin_lock_irqsave(struct bpf_res_spin_lock *lock, unsigned long *flags__irq_flag)\nkernel/bpf/rqspinlock.c-717-{\n--\nkernel/bpf/rqspinlock.c-723-\tlocal_irq_save(flags);\nkernel/bpf/rqspinlock.c:724:\tret = res_spin_lock((rqspinlock_t *)lock);\nkernel/bpf/rqspinlock.c-725-\tif (unlikely(ret)) {\n--\nkernel/bpf/rqspinlock.c-734-\nkernel/bpf/rqspinlock.c:735:__bpf_kfunc void bpf_res_spin_unlock_irqrestore(struct bpf_res_spin_lock *lock, unsigned long *flags__irq_flag)\nkernel/bpf/rqspinlock.c-736-{\n--\nkernel/bpf/rqspinlock.c=747=BTF_KFUNCS_START(rqspinlock_kfunc_ids)\nkernel/bpf/rqspinlock.c:748:BTF_ID_FLAGS(func, bpf_res_spin_lock, KF_RET_NULL)\nkernel/bpf/rqspinlock.c-749-BTF_ID_FLAGS(func, bpf_res_spin_unlock)\nkernel/bpf/rqspinlock.c:750:BTF_ID_FLAGS(func, bpf_res_spin_lock_irqsave, KF_RET_NULL)\nkernel/bpf/rqspinlock.c-751-BTF_ID_FLAGS(func, bpf_res_spin_unlock_irqrestore)\n--\nkernel/bpf/verifier.c=6976=static int process_spin_lock(struct bpf_verifier_env *env, struct bpf_reg_state *reg, argno_t argno, int flags)\n--\nkernel/bpf/verifier.c-7013-\t}\nkernel/bpf/verifier.c:7014:\tspin_lock_off = is_res_lock ? rec-\u003eres_spin_lock_off : rec-\u003espin_lock_off;\nkernel/bpf/verifier.c-7015-\tif (spin_lock_off != val) {\n--\nkernel/bpf/verifier.c=10823=BTF_ID(struct, bpf_wq)\nkernel/bpf/verifier.c:10824:BTF_ID(struct, bpf_res_spin_lock)\nkernel/bpf/verifier.c-10825-BTF_ID(struct, bpf_task_work)\n--\nkernel/bpf/verifier.c=10881=static bool is_kfunc_arg_task_work(const struct btf *btf, const struct btf_param *arg)\n--\nkernel/bpf/verifier.c-10885-\nkernel/bpf/verifier.c:10886:static bool is_kfunc_arg_res_spin_lock(const struct btf *btf, const struct btf_param *arg)\nkernel/bpf/verifier.c-10887-{\n--\nkernel/bpf/verifier.c=11004=enum special_kfunc_type {\n--\nkernel/bpf/verifier.c-11059-\tKF_bpf_remove_dentry_xattr,\nkernel/bpf/verifier.c:11060:\tKF_bpf_res_spin_lock,\nkernel/bpf/verifier.c-11061-\tKF_bpf_res_spin_unlock,\nkernel/bpf/verifier.c:11062:\tKF_bpf_res_spin_lock_irqsave,\nkernel/bpf/verifier.c-11063-\tKF_bpf_res_spin_unlock_irqrestore,\n--\nkernel/bpf/verifier.c=11151=BTF_ID_UNUSED\nkernel/bpf/verifier.c-11152-#endif\nkernel/bpf/verifier.c:11153:BTF_ID(func, bpf_res_spin_lock)\nkernel/bpf/verifier.c-11154-BTF_ID(func, bpf_res_spin_unlock)\nkernel/bpf/verifier.c:11155:BTF_ID(func, bpf_res_spin_lock_irqsave)\nkernel/bpf/verifier.c-11156-BTF_ID(func, bpf_res_spin_unlock_irqrestore)\n--\nkernel/bpf/verifier.c=11258=get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, struct bpf_func_state *caller,\n--\nkernel/bpf/verifier.c-11329-\nkernel/bpf/verifier.c:11330:\tif (is_kfunc_arg_res_spin_lock(meta-\u003ebtf, \u0026args[arg]))\nkernel/bpf/verifier.c-11331-\t\treturn KF_ARG_PTR_TO_RES_SPIN_LOCK;\n--\nkernel/bpf/verifier.c=11433=static int process_irq_flag(struct bpf_verifier_env *env, struct bpf_reg_state *reg, argno_t argno,\n--\nkernel/bpf/verifier.c-11439-\tif (meta-\u003efunc_id == special_kfunc_list[KF_bpf_local_irq_save] ||\nkernel/bpf/verifier.c:11440:\t    meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave]) {\nkernel/bpf/verifier.c-11441-\t\tirq_save = true;\nkernel/bpf/verifier.c:11442:\t\tif (meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave])\nkernel/bpf/verifier.c-11443-\t\t\tkfunc_class = IRQ_LOCK_KFUNC;\n--\nkernel/bpf/verifier.c=11632=static bool is_bpf_graph_api_kfunc(u32 btf_id)\n--\nkernel/bpf/verifier.c-11638-\nkernel/bpf/verifier.c:11639:static bool is_bpf_res_spin_lock_kfunc(u32 btf_id)\nkernel/bpf/verifier.c-11640-{\nkernel/bpf/verifier.c:11641:\treturn btf_id == special_kfunc_list[KF_bpf_res_spin_lock] ||\nkernel/bpf/verifier.c-11642-\t       btf_id == special_kfunc_list[KF_bpf_res_spin_unlock] ||\nkernel/bpf/verifier.c:11643:\t       btf_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave] ||\nkernel/bpf/verifier.c-11644-\t       btf_id == special_kfunc_list[KF_bpf_res_spin_unlock_irqrestore];\n--\nkernel/bpf/verifier.c=11660=static bool kfunc_spin_allowed(u32 btf_id)\n--\nkernel/bpf/verifier.c-11662-\treturn is_bpf_graph_api_kfunc(btf_id) || is_bpf_iter_num_api_kfunc(btf_id) ||\nkernel/bpf/verifier.c:11663:\t       is_bpf_res_spin_lock_kfunc(btf_id) || is_bpf_arena_kfunc(btf_id) ||\nkernel/bpf/verifier.c-11664-\t       is_bpf_stream_kfunc(btf_id);\n--\nkernel/bpf/verifier.c=11928=static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_arg_meta *meta,\n--\nkernel/bpf/verifier.c-12499-\nkernel/bpf/verifier.c:12500:\t\t\tif (!is_bpf_res_spin_lock_kfunc(meta-\u003efunc_id))\nkernel/bpf/verifier.c-12501-\t\t\t\treturn -EFAULT;\nkernel/bpf/verifier.c:12502:\t\t\tif (meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_lock] ||\nkernel/bpf/verifier.c:12503:\t\t\t    meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave])\nkernel/bpf/verifier.c-12504-\t\t\t\tflags |= PROCESS_SPIN_LOCK;\nkernel/bpf/verifier.c:12505:\t\t\tif (meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave] ||\nkernel/bpf/verifier.c-12506-\t\t\t    meta-\u003efunc_id == special_kfunc_list[KF_bpf_res_spin_unlock_irqrestore])\n--\nkernel/bpf/verifier.c=12913=static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,\n--\nkernel/bpf/verifier.c-12944-\tif (!insn-\u003eoff \u0026\u0026\nkernel/bpf/verifier.c:12945:\t    (insn-\u003eimm == special_kfunc_list[KF_bpf_res_spin_lock] ||\nkernel/bpf/verifier.c:12946:\t     insn-\u003eimm == special_kfunc_list[KF_bpf_res_spin_lock_irqsave])) {\nkernel/bpf/verifier.c-12947-\t\tstruct bpf_verifier_state *branch;\n--\nkernel/bpf/verifier.c-13141-\t\tmark_reg_unknown(env, regs, BPF_REG_0);\nkernel/bpf/verifier.c:13142:\t\tif (meta.btf == btf_vmlinux \u0026\u0026 (meta.func_id == special_kfunc_list[KF_bpf_res_spin_lock] ||\nkernel/bpf/verifier.c:13143:\t\t    meta.func_id == special_kfunc_list[KF_bpf_res_spin_lock_irqsave]))\nkernel/bpf/verifier.c-13144-\t\t\t__mark_reg_const_zero(env, \u0026regs[BPF_REG_0]);\n--\nkernel/locking/locktorture.c=370=static int torture_raw_res_spin_write_lock(int tid __maybe_unused)\nkernel/locking/locktorture.c-371-{\nkernel/locking/locktorture.c:372:\traw_res_spin_lock(\u0026rqspinlock);\nkernel/locking/locktorture.c-373-\treturn 0;\n--\nkernel/locking/locktorture.c=376=static void torture_raw_res_spin_write_unlock(int tid __maybe_unused)\n--\nkernel/locking/locktorture.c-380-\nkernel/locking/locktorture.c:381:static struct lock_torture_ops raw_res_spin_lock_ops = {\nkernel/locking/locktorture.c-382-\t.writelock\t= torture_raw_res_spin_write_lock,\n--\nkernel/locking/locktorture.c-388-\t.readunlock     = NULL,\nkernel/locking/locktorture.c:389:\t.name\t\t= \"raw_res_spin_lock\"\nkernel/locking/locktorture.c-390-};\n--\nkernel/locking/locktorture.c=392=static int torture_raw_res_spin_write_lock_irq(int tid __maybe_unused)\n--\nkernel/locking/locktorture.c-395-\nkernel/locking/locktorture.c:396:\traw_res_spin_lock_irqsave(\u0026rqspinlock, flags);\nkernel/locking/locktorture.c-397-\tcxt.cur_ops-\u003eflags = flags;\n--\nkernel/locking/locktorture.c=401=static void torture_raw_res_spin_write_unlock_irq(int tid __maybe_unused)\n--\nkernel/locking/locktorture.c-405-\nkernel/locking/locktorture.c:406:static struct lock_torture_ops raw_res_spin_lock_irq_ops = {\nkernel/locking/locktorture.c-407-\t.writelock\t= torture_raw_res_spin_write_lock_irq,\n\n"
}

gemini-3.1-pro-preview

							input: 21279
							output: 37
							thoughts: 202

**Analyzing BPF Spin Lock Usage**

Okay, so I'm thinking about this `resilient_queued_spin_lock_slowpath`. I know that function is crucial because it's at the heart of `bpf_res_spin_lock` and `bpf_res_spin_lock_irqsave`, both of which are, of course, BPF kfuncs. It's also utilized by `raw_res_spin_lock`, and that's used across the BPF codebase – arena management, local storage, the LRU list, all of it. Given that widespread usage, it's definitely reachable from BPF syscalls.

Therefore, the key symbols I need to focus on right now are `resilient_queued_spin_lock_slowpath`, `bpf_res_spin_lock`, and `bpf_res_spin_lock_irqsave`. I need to confirm that `bpf_res_spin_lock` and `bpf_res_spin_lock_irqsave` aren't exported as standard functions, but are defined purely as kfuncs. *Checks internal documentation* Yes, they are indeed kfuncs. Now, I'm going to take another look at `kernel/bpf/rqspinlock.c` and make sure I haven't missed anything.

{
  "Expression": "bpf_res_spin_lock",
  "PathPrefix": "kernel/bpf/rqspinlock.c"
}

{
  "Output": "kernel/bpf/rqspinlock.c=673=static void bpf_prog_report_rqspinlock_violation(const char *str, void *lock, bool irqsave)\n--\nkernel/bpf/rqspinlock.c-682-\tbpf_stream_stage(ss, prog, BPF_STDERR, ({\nkernel/bpf/rqspinlock.c:683:\t\tbpf_stream_printk(ss, \"ERROR: %s for bpf_res_spin_lock%s\\n\", str, irqsave ? \"_irqsave\" : \"\");\nkernel/bpf/rqspinlock.c-684-\t\tbpf_stream_printk(ss, \"Attempted lock   = 0x%px\\n\", lock);\n--\nkernel/bpf/rqspinlock.c-693-\nkernel/bpf/rqspinlock.c:694:__bpf_kfunc int bpf_res_spin_lock(struct bpf_res_spin_lock *lock)\nkernel/bpf/rqspinlock.c-695-{\n--\nkernel/bpf/rqspinlock.c-697-\nkernel/bpf/rqspinlock.c:698:\tBUILD_BUG_ON(sizeof(rqspinlock_t) != sizeof(struct bpf_res_spin_lock));\nkernel/bpf/rqspinlock.c-699-\n--\nkernel/bpf/rqspinlock.c-709-\nkernel/bpf/rqspinlock.c:710:__bpf_kfunc void bpf_res_spin_unlock(struct bpf_res_spin_lock *lock)\nkernel/bpf/rqspinlock.c-711-{\n--\nkernel/bpf/rqspinlock.c-715-\nkernel/bpf/rqspinlock.c:716:__bpf_kfunc int bpf_res_spin_lock_irqsave(struct bpf_res_spin_lock *lock, unsigned long *flags__irq_flag)\nkernel/bpf/rqspinlock.c-717-{\n--\nkernel/bpf/rqspinlock.c-734-\nkernel/bpf/rqspinlock.c:735:__bpf_kfunc void bpf_res_spin_unlock_irqrestore(struct bpf_res_spin_lock *lock, unsigned long *flags__irq_flag)\nkernel/bpf/rqspinlock.c-736-{\n--\nkernel/bpf/rqspinlock.c=747=BTF_KFUNCS_START(rqspinlock_kfunc_ids)\nkernel/bpf/rqspinlock.c:748:BTF_ID_FLAGS(func, bpf_res_spin_lock, KF_RET_NULL)\nkernel/bpf/rqspinlock.c-749-BTF_ID_FLAGS(func, bpf_res_spin_unlock)\nkernel/bpf/rqspinlock.c:750:BTF_ID_FLAGS(func, bpf_res_spin_lock_irqsave, KF_RET_NULL)\nkernel/bpf/rqspinlock.c-751-BTF_ID_FLAGS(func, bpf_res_spin_unlock_irqrestore)\n"
}

gemini-3.1-pro-preview

							input: 22580
							output: 34
							thoughts: 101

**Analyzing BPF Spin Locks and Configuration Dependencies**

Okay, so I'm looking at these BPF spin lock functions, specifically `bpf_res_spin_lock` and `bpf_res_spin_lock_irqsave`. They seem like prime candidates to include in `FocusSymbols`. That makes sense. Also, I'm noting that `resilient_queued_spin_lock_slowpath` is the one that's been modified, which is important to remember.

Now, the configuration in play here is `BPF_SYSCALL`. But wait a minute... is that *all*? I need to be sure I've got the full picture. Let's dig into `kernel/bpf/Kconfig` and see if there are any other dependencies associated with `BPF_SYSCALL`. I need to understand all the conditions that might impact this code. Gotta make sure I'm not missing any pieces of the puzzle.

{
  "Expression": "config BPF_SYSCALL",
  "PathPrefix": "kernel/bpf/Kconfig"
}

{
  "Output": "kernel/bpf/Kconfig=25=menu \"BPF subsystem\"\nkernel/bpf/Kconfig-26-\nkernel/bpf/Kconfig:27:config BPF_SYSCALL\nkernel/bpf/Kconfig-28-\tbool \"Enable bpf() system call\"\n"
}

gemini-3.1-pro-preview

							input: 23002
							output: 154
							thoughts: 384

**Analyzing a BPF Spinlock Patch**

Okay, so this is about `BPF_SYSCALL`, nothing too obscure. Let's start by seeing if there are any architecture-specific configurations that might be relevant. Right, `CONFIG_QUEUED_SPINLOCKS` is selected by `ARCH_USE_QUEUED_SPINLOCKS`. Good, good, we can just focus on `BPF_SYSCALL` then.

Alright, let's take another look at this patch. It seems to be cleaning up a deadlock scenario. Specifically, it seems like the fix addresses a bug in `resilient_queued_spin_lock_slowpath`. I see the code snippet now, changing the logic where it's handling `EDEADLK`, looks like they're trying to prevent queue destruction on deadlock, with a `try_cmpxchg_tail`.

This looks functional and reachable, which is important. This path is definitely called, specifically by the `resilient_queued_spin_lock_slowpath` function. And that's part of the BPF resilient queued spinlock implementation. This spinlock gets used by `bpf_res_spin_lock` and `bpf_res_spin_lock_irqsave` kfuncs, and by BPF maps internally. This is an area we should definitely fuzz.

{
  "EnableConfigs": [
    "BPF_SYSCALL"
  ],
  "FocusSymbols": [
    "resilient_queued_spin_lock_slowpath",
    "bpf_res_spin_lock",
    "bpf_res_spin_lock_irqsave"
  ],
  "Reasoning": "The patch modifies the deadlock handling logic in `resilient_queued_spin_lock_slowpath`, which is part of the BPF resilient queued spinlock implementation. This code is reachable from BPF programs using `bpf_res_spin_lock` kfuncs, as well as internally by various BPF maps. It is functional and should be fuzzed.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "BPF_SYSCALL"
  ],
  "FocusSymbols": [
    "resilient_queued_spin_lock_slowpath",
    "bpf_res_spin_lock",
    "bpf_res_spin_lock_irqsave"
  ],
  "Reasoning": "The patch modifies the deadlock handling logic in `resilient_queued_spin_lock_slowpath`, which is part of the BPF resilient queued spinlock implementation. This code is reachable from BPF programs using `bpf_res_spin_lock` kfuncs, as well as internally by various BPF maps. It is functional and should be fuzzed.",
  "WorthFuzzing": true
}

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)