AI Trajectory

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only refactors the extraction of the 'nowait' flag into a local variable and passes it as the 'trylock' parameter to rwsem_acquire_read(). Since rwsem_acquire_read() is purely a lockdep annotation macro that expands to nothing when CONFIG_LOCKDEP is disabled, this patch does not functionally alter the execution flow of the kernel and is not worth fuzzing.",
  "WorthFuzzing": false
}

null

{
  "PatchDiff": "commit 85c3220a259f8f413eeb8e9fd8ac6cb09a64147d\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Sat Aug 1 07:11:19 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/block/blk-core.c b/block/blk-core.c\nindex 365641266c9e8..e5db54596e3dd 100644\n--- a/block/blk-core.c\n+++ b/block/blk-core.c\n@@ -347,9 +347,10 @@ bool blk_queue_start_drain(struct request_queue *q)\n int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)\n {\n \tconst bool pm = flags \u0026 BLK_MQ_REQ_PM;\n+\tconst bool nowait = flags \u0026 BLK_MQ_REQ_NOWAIT;\n \n \twhile (!blk_try_enter_queue(q, pm)) {\n-\t\tif (flags \u0026 BLK_MQ_REQ_NOWAIT)\n+\t\tif (nowait)\n \t\t\treturn -EAGAIN;\n \n \t\t/*\n@@ -368,17 +369,19 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)\n \t\t\treturn -ENODEV;\n \t}\n \n-\trwsem_acquire_read(\u0026q-\u003eq_lockdep_map, 0, 0, _RET_IP_);\n+\trwsem_acquire_read(\u0026q-\u003eq_lockdep_map, 0, nowait, _RET_IP_);\n \trwsem_release(\u0026q-\u003eq_lockdep_map, _RET_IP_);\n \treturn 0;\n }\n \n int __bio_queue_enter(struct request_queue *q, struct bio *bio)\n {\n+\tconst bool nowait = bio-\u003ebi_opf \u0026 REQ_NOWAIT;\n+\n \twhile (!blk_try_enter_queue(q, false)) {\n \t\tstruct gendisk *disk = bio-\u003ebi_bdev-\u003ebd_disk;\n \n-\t\tif (bio-\u003ebi_opf \u0026 REQ_NOWAIT) {\n+\t\tif (nowait) {\n \t\t\tif (test_bit(GD_DEAD, \u0026disk-\u003estate))\n \t\t\t\tgoto dead;\n \t\t\tbio_wouldblock_error(bio);\n@@ -401,7 +404,7 @@ int __bio_queue_enter(struct request_queue *q, struct bio *bio)\n \t\t\tgoto dead;\n \t}\n \n-\trwsem_acquire_read(\u0026q-\u003eio_lockdep_map, 0, 0, _RET_IP_);\n+\trwsem_acquire_read(\u0026q-\u003eio_lockdep_map, 0, nowait, _RET_IP_);\n \trwsem_release(\u0026q-\u003eio_lockdep_map, _RET_IP_);\n \treturn 0;\n dead:\n"
}

best-expensive

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only refactors the extraction of the 'nowait' flag into a local variable and passes it as the 'trylock' parameter to rwsem_acquire_read(). Since rwsem_acquire_read() is purely a lockdep annotation macro that expands to nothing when CONFIG_LOCKDEP is disabled, this patch does not functionally alter the execution flow of the kernel and is not worth fuzzing.",
  "WorthFuzzing": false
}

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 85c3220a259f8f413eeb8e9fd8ac6cb09a64147d
Author: syz-cluster <triage@syzkaller.com>
Date:   Sat Aug 1 07:11:19 2026 +0000

    syz-cluster: applied patch under review

diff --git a/block/blk-core.c b/block/blk-core.c
index 365641266c9e8..e5db54596e3dd 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -347,9 +347,10 @@ bool blk_queue_start_drain(struct request_queue *q)
 int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
 {
 	const bool pm = flags & BLK_MQ_REQ_PM;
+	const bool nowait = flags & BLK_MQ_REQ_NOWAIT;
 
 	while (!blk_try_enter_queue(q, pm)) {
-		if (flags & BLK_MQ_REQ_NOWAIT)
+		if (nowait)
 			return -EAGAIN;
 
 		/*
@@ -368,17 +369,19 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
 			return -ENODEV;
 	}
 
-	rwsem_acquire_read(&q->q_lockdep_map, 0, 0, _RET_IP_);
+	rwsem_acquire_read(&q->q_lockdep_map, 0, nowait, _RET_IP_);
 	rwsem_release(&q->q_lockdep_map, _RET_IP_);
 	return 0;
 }
 
 int __bio_queue_enter(struct request_queue *q, struct bio *bio)
 {
+	const bool nowait = bio->bi_opf & REQ_NOWAIT;
+
 	while (!blk_try_enter_queue(q, false)) {
 		struct gendisk *disk = bio->bi_bdev->bd_disk;
 
-		if (bio->bi_opf & REQ_NOWAIT) {
+		if (nowait) {
 			if (test_bit(GD_DEAD, &disk->state))
 				goto dead;
 			bio_wouldblock_error(bio);
@@ -401,7 +404,7 @@ int __bio_queue_enter(struct request_queue *q, struct bio *bio)
 			goto dead;
 	}
 
-	rwsem_acquire_read(&q->io_lockdep_map, 0, 0, _RET_IP_);
+	rwsem_acquire_read(&q->io_lockdep_map, 0, nowait, _RET_IP_);
 	rwsem_release(&q->io_lockdep_map, _RET_IP_);
 	return 0;
 dead:

gemini-3.1-pro-preview

null

null

							input: 2528
							output: 21
							thoughts: 235
						

**Analyzing a Patch: Lockdep Implications in Block Layer**

Okay, so I'm looking at this patch for `block/blk-core.c`. The core of the change seems to be in `blk_queue_enter` and `__bio_queue_enter`. It's tweaking how we're calling `rwsem_acquire_read`. Specifically, the `nowait` flag is being introduced as the `trylock` parameter. This immediately flags something – this has to be related to lockdep tracking for request queues.

Wait, `rwsem_acquire_read`... that's a lockdep annotation, isn't it? I need to confirm. I should check its definition. It should be in `include/linux/lockdep.h` or somewhere similar. If it *is* just a lockdep wrapper, then this might not be a direct functional change in terms of the *execution* flow. It's an important change, but it's *about* lockdep.

Wait, though… does it affect the execution flow *at all*? Hmm. `rwsem_acquire_read`... it's a macro. I need to know what it expands to. It expands to `lock_acquire` when `CONFIG_LOCKDEP` is enabled. If `CONFIG_LOCKDEP` is disabled, it probably expands to… nothing? This is important. I better double-check in `include/linux/lockdep.h` to be sure. This change could have more implications than I initially thought depending on how lockdep is configured in a system.

{
  "Expression": "define rwsem_acquire_read"
}

{
  "Output": "include/linux/lockdep.h=519=do {\t\t\t\t\t\t\t\t\t\\\n--\ninclude/linux/lockdep.h-537-#define rwsem_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\ninclude/linux/lockdep.h:538:#define rwsem_acquire_read(l, s, t, i)\t\tlock_acquire_shared(l, s, t, NULL, i)\ninclude/linux/lockdep.h-539-#define rwsem_release(l, i)\t\t\tlock_release(l, i)\n"
}

gemini-3.1-pro-preview

null

null

							input: 3280
							output: 22
							thoughts: 27
						

Here's my thought process, summarized as you requested:

**Investigating a Potential Lockdep Optimization**

Okay, let's dive into this. My immediate question is whether the `rwsem_acquire_read` function is simply a no-op, an empty definition, in the kernel's code when the `CONFIG_LOCKDEP` option is turned off. I need to quickly determine if we're dealing with a conditionally compiled section of code, or if `CONFIG_LOCKDEP` has no impact on this particular function. This will help me understand potential performance implications and whether we can streamline the code in a lockdep-free environment. I need to get this basic question answered before I can form an opinion about this code.

{
  "Expression": "#define rwsem_acquire_read"
}

{
  "Output": "include/linux/lockdep.h=519=do {\t\t\t\t\t\t\t\t\t\\\n--\ninclude/linux/lockdep.h-537-#define rwsem_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\ninclude/linux/lockdep.h:538:#define rwsem_acquire_read(l, s, t, i)\t\tlock_acquire_shared(l, s, t, NULL, i)\ninclude/linux/lockdep.h-539-#define rwsem_release(l, i)\t\t\tlock_release(l, i)\n"
}

gemini-3.1-pro-preview

null

null

							input: 3643
							output: 36
							thoughts: 21
						

Here's a summary of my thought process, keeping in mind my expert understanding:

**Deep Dive into Lockdep**

Okay, so I'm thinking, "Where's the best place to start untangling this issue?" My mind immediately jumps to `include/linux/lockdep.h` – that's the heart of the lock dependency detection mechanism in the kernel. Specifically, I'm zeroing in around line 538. I'm not going to pretend to know *exactly* what's there off the top of my head, but I know the general structure of the code around that area. Line 538 is likely a critical section of code related to reporting lockdep errors, handling lock classes, or perhaps the recursive locking detection. I have a feeling the problem I'm trying to solve will be rooted somewhere in that vicinity, so that's the logical jumping-off point for a deeper investigation. Let's see what we can find.

{
  "File": "include/linux/lockdep.h",
  "FirstLine": 520,
  "LineCount": 50
}

{
  "Contents": " 520:\t\tif (read_lock_is_recursive())\t\t\t\t\t\\\n 521:\t\t\tlock_acquire_shared_recursive(l, s, t, NULL, i);\t\\\n 522:\t\telse\t\t\t\t\t\t\t\t\\\n 523:\t\t\tlock_acquire_shared(l, s, t, NULL, i);\t\t\t\\\n 524:\t} while (0)\n 525:\t\n 526:\t#define rwlock_release(l, i)\t\t\tlock_release(l, i)\n 527:\t\n 528:\t#define seqcount_acquire(l, s, t, i)\t\tlock_acquire_exclusive(l, s, t, NULL, i)\n 529:\t#define seqcount_acquire_read(l, s, t, i)\tlock_acquire_shared_recursive(l, s, t, NULL, i)\n 530:\t#define seqcount_release(l, i)\t\t\tlock_release(l, i)\n 531:\t\n 532:\t#define mutex_acquire(l, s, t, i)\t\tlock_acquire_exclusive(l, s, t, NULL, i)\n 533:\t#define mutex_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\n 534:\t#define mutex_release(l, i)\t\t\tlock_release(l, i)\n 535:\t\n 536:\t#define rwsem_acquire(l, s, t, i)\t\tlock_acquire_exclusive(l, s, t, NULL, i)\n 537:\t#define rwsem_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\n 538:\t#define rwsem_acquire_read(l, s, t, i)\t\tlock_acquire_shared(l, s, t, NULL, i)\n 539:\t#define rwsem_release(l, i)\t\t\tlock_release(l, i)\n 540:\t\n 541:\t#define lock_map_acquire(l)\t\t\tlock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)\n 542:\t#define lock_map_acquire_try(l)\t\t\tlock_acquire_exclusive(l, 0, 1, NULL, _THIS_IP_)\n 543:\t#define lock_map_acquire_read(l)\t\tlock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)\n 544:\t#define lock_map_acquire_tryread(l)\t\tlock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)\n 545:\t#define lock_map_release(l)\t\t\tlock_release(l, _THIS_IP_)\n 546:\t#define lock_map_sync(l)\t\t\tlock_sync(l, 0, 0, 1, NULL, _THIS_IP_)\n 547:\t\n 548:\t#ifdef CONFIG_PROVE_LOCKING\n 549:\t# define might_lock(lock)\t\t\t\t\t\t\\\n 550:\tdo {\t\t\t\t\t\t\t\t\t\\\n 551:\t\ttypecheck(struct lockdep_map *, \u0026(lock)-\u003edep_map);\t\t\\\n 552:\t\tlock_acquire(\u0026(lock)-\u003edep_map, 0, 0, 0, 1, NULL, _THIS_IP_);\t\\\n 553:\t\tlock_release(\u0026(lock)-\u003edep_map, _THIS_IP_);\t\t\t\\\n 554:\t} while (0)\n 555:\t# define might_lock_read(lock)\t\t\t\t\t\t\\\n 556:\tdo {\t\t\t\t\t\t\t\t\t\\\n 557:\t\ttypecheck(struct lockdep_map *, \u0026(lock)-\u003edep_map);\t\t\\\n 558:\t\tlock_acquire(\u0026(lock)-\u003edep_map, 0, 0, 1, 1, NULL, _THIS_IP_);\t\\\n 559:\t\tlock_release(\u0026(lock)-\u003edep_map, _THIS_IP_);\t\t\t\\\n 560:\t} while (0)\n 561:\t# define might_lock_nested(lock, subclass)\t\t\t\t\\\n 562:\tdo {\t\t\t\t\t\t\t\t\t\\\n 563:\t\ttypecheck(struct lockdep_map *, \u0026(lock)-\u003edep_map);\t\t\\\n 564:\t\tlock_acquire(\u0026(lock)-\u003edep_map, subclass, 0, 1, 1, NULL,\t\t\\\n 565:\t\t\t     _THIS_IP_);\t\t\t\t\t\\\n 566:\t\tlock_release(\u0026(lock)-\u003edep_map, _THIS_IP_);\t\t\t\\\n 567:\t} while (0)\n 568:\t\n 569:\tDECLARE_PER_CPU(int, hardirqs_enabled);\n"
}

gemini-3.1-pro-preview

null

null

							input: 5121
							output: 36
							thoughts: 25
						

Okay, here's my summary, tailored for an expert audience, as if I'm thinking these things myself:

**Tracing the Definition of `rwsem_acquire_read` (CONFIG_LOCKDEP Disabled)**

Alright, so I need to find the definition of `rwsem_acquire_read` when `CONFIG_LOCKDEP` is *off*. That's the key. I know where to start looking, but it's important to remember that without `LOCKDEP`, the implementation likely takes a different path, probably a simpler one that bypasses some of the more elaborate locking dependency tracking. I expect it to be a more straightforward implementation involving atomic operations and potentially interrupt disabling, but I need to confirm this. I will look for preprocessor directives or conditional compilation to direct me to the correct definition. It's possible the core logic is in a general header, but I'll need to follow the includes carefully to ensure I'm getting the right version for a non-`LOCKDEP` configuration. Time to start digging in the kernel source.

{
  "Expression": "#define rwsem_acquire_read",
  "PathPrefix": "include/linux/lockdep.h"
}

{
  "Output": "include/linux/lockdep.h=519=do {\t\t\t\t\t\t\t\t\t\\\n--\ninclude/linux/lockdep.h-537-#define rwsem_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\ninclude/linux/lockdep.h:538:#define rwsem_acquire_read(l, s, t, i)\t\tlock_acquire_shared(l, s, t, NULL, i)\ninclude/linux/lockdep.h-539-#define rwsem_release(l, i)\t\t\tlock_release(l, i)\n"
}

gemini-3.1-pro-preview

null

null

							input: 5562
							output: 34
							thoughts: 26
						

Okay, here's my attempt at summarizing that thought process, keeping in mind I'm speaking to a fellow expert:

**Finding the Lockdep Definition**

Right, let's revisit that `rwsem_acquire_read` search. I need to nail down exactly how the lock dependency analysis, specifically within `lockdep`, handles read semaphore acquisitions. The most likely spot to find the core definition and related instrumentation is still `include/linux/lockdep.h`. I'll zero in on that file again, see if my intuition from the last search holds up or if I missed something subtle the first time around. Time to confirm my understanding of that crucial section.

{
  "Expression": "rwsem_acquire_read",
  "PathPrefix": "include/linux/lockdep.h"
}

{
  "Output": "include/linux/lockdep.h=519=do {\t\t\t\t\t\t\t\t\t\\\n--\ninclude/linux/lockdep.h-537-#define rwsem_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\ninclude/linux/lockdep.h:538:#define rwsem_acquire_read(l, s, t, i)\t\tlock_acquire_shared(l, s, t, NULL, i)\ninclude/linux/lockdep.h-539-#define rwsem_release(l, i)\t\t\tlock_release(l, i)\n"
}

gemini-3.1-pro-preview

null

null

							input: 5923
							output: 30
							thoughts: 55
						

Okay, let's see...

**Checking the Read-Write Semaphore Implementation with Lock Dependency Disabled**

Hmm, a question just popped into my head. If the kernel's lock dependency checker (`CONFIG_LOCKDEP`) is disabled, does that mean that the `rwsem_acquire_read` function becomes a no-op? I need to verify that and see what it's defined as when lockdep isn't enabled.

I know where to look. I'll check either `include/linux/rwsem.h` which should contain the core definition of read-write semaphores, or `include/linux/lockdep.h` to see if there's a conditional fallback implementation or a macro involved when `CONFIG_LOCKDEP` is turned off. Let's see what's actually going on under the hood. It's probably a macro, given the way that's usually handled.

{
  "Expression": "rwsem_acquire_read",
  "PathPrefix": "include/linux/"
}

{
  "Output": "include/linux/lockdep.h=519=do {\t\t\t\t\t\t\t\t\t\\\n--\ninclude/linux/lockdep.h-537-#define rwsem_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\ninclude/linux/lockdep.h:538:#define rwsem_acquire_read(l, s, t, i)\t\tlock_acquire_shared(l, s, t, NULL, i)\ninclude/linux/lockdep.h-539-#define rwsem_release(l, i)\t\t\tlock_release(l, i)\n--\ninclude/linux/percpu-rwsem.h=48=static inline void percpu_down_read_internal(struct percpu_rw_semaphore *sem,\n--\ninclude/linux/percpu-rwsem.h-52-\ninclude/linux/percpu-rwsem.h:53:\trwsem_acquire_read(\u0026sem-\u003edep_map, 0, 0, _RET_IP_);\ninclude/linux/percpu-rwsem.h-54-\n--\ninclude/linux/percpu-rwsem.h=86=static inline bool percpu_down_read_trylock(struct percpu_rw_semaphore *sem)\n--\ninclude/linux/percpu-rwsem.h-104-\tif (ret)\ninclude/linux/percpu-rwsem.h:105:\t\trwsem_acquire_read(\u0026sem-\u003edep_map, 0, 1, _RET_IP_);\ninclude/linux/percpu-rwsem.h-106-\n"
}

gemini-3.1-pro-preview

null

null

							input: 6601
							output: 37
							thoughts: 38
						

Here's my take on the thought process:

**Diving into the Kernel Lock Structures**

Okay, so I'm looking at this code and need to understand where `rwsem_acquire_read` is actually defined. I know it's related to read/write semaphores, so my gut feeling is that it's going to be somewhere in the core kernel headers. Let's see... ah, right! `rwsem_acquire_read` is defined in `include/linux/lockdep.h`. I recall that file being the home of lock debugging and analysis tools. Alright, let's open that file and head over to around line 538. I need to get a better sense of what this definition looks like in its context within the lockdep infrastructure. I'm hoping to get some details about exactly *how* this read semaphore acquire is tracked and implemented within the kernel's lock debugging framework.

{
  "File": "include/linux/lockdep.h",
  "FirstLine": 400,
  "LineCount": 100
}

{
  "Contents": " 400:\t\n 401:\t#define NIL_COOKIE (struct pin_cookie){ }\n 402:\t\n 403:\t#define lockdep_pin_lock(l)\t\t\t({ struct pin_cookie cookie = { }; cookie; })\n 404:\t#define lockdep_repin_lock(l, c)\t\tdo { (void)(l); (void)(c); } while (0)\n 405:\t#define lockdep_unpin_lock(l, c)\t\tdo { (void)(l); (void)(c); } while (0)\n 406:\t\n 407:\t#define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type)\t\\\n 408:\t\tstruct lockdep_map __maybe_unused _name = {}\n 409:\t\n 410:\t#endif /* !LOCKDEP */\n 411:\t\n 412:\t#ifdef CONFIG_PROVE_LOCKING\n 413:\tvoid lockdep_set_lock_cmp_fn(struct lockdep_map *, lock_cmp_fn, lock_print_fn);\n 414:\t\n 415:\t#define lock_set_cmp_fn(lock, ...)\tlockdep_set_lock_cmp_fn(\u0026(lock)-\u003edep_map, __VA_ARGS__)\n 416:\t#else\n 417:\t#define lock_set_cmp_fn(lock, ...)\tdo { } while (0)\n 418:\t#endif\n 419:\t\n 420:\tenum xhlock_context_t {\n 421:\t\tXHLOCK_HARD,\n 422:\t\tXHLOCK_SOFT,\n 423:\t\tXHLOCK_CTX_NR,\n 424:\t};\n 425:\t\n 426:\t/*\n 427:\t * To initialize a lockdep_map statically use this macro.\n 428:\t * Note that _name must not be NULL.\n 429:\t */\n 430:\t#define STATIC_LOCKDEP_MAP_INIT(_name, _key) \\\n 431:\t\t{ .name = (_name), .key = (void *)(_key), }\n 432:\t\n 433:\tstatic inline void lockdep_invariant_state(bool force) {}\n 434:\tstatic inline void lockdep_free_task(struct task_struct *task) {}\n 435:\t\n 436:\t#ifdef CONFIG_LOCK_STAT\n 437:\t\n 438:\textern void lock_contended(struct lockdep_map *lock, unsigned long ip);\n 439:\textern void lock_acquired(struct lockdep_map *lock, unsigned long ip);\n 440:\t\n 441:\t#define LOCK_CONTENDED(_lock, try, lock)\t\t\t\\\n 442:\tdo {\t\t\t\t\t\t\t\t\\\n 443:\t\tif (!try(_lock)) {\t\t\t\t\t\\\n 444:\t\t\tlock_contended(\u0026(_lock)-\u003edep_map, _RET_IP_);\t\\\n 445:\t\t\tlock(_lock);\t\t\t\t\t\\\n 446:\t\t}\t\t\t\t\t\t\t\\\n 447:\t\tlock_acquired(\u0026(_lock)-\u003edep_map, _RET_IP_);\t\t\t\\\n 448:\t} while (0)\n 449:\t\n 450:\t#define LOCK_CONTENDED_RETURN(_lock, try, lock)\t\t\t\\\n 451:\t({\t\t\t\t\t\t\t\t\\\n 452:\t\tint ____err = 0;\t\t\t\t\t\\\n 453:\t\tif (!try(_lock)) {\t\t\t\t\t\\\n 454:\t\t\tlock_contended(\u0026(_lock)-\u003edep_map, _RET_IP_);\t\\\n 455:\t\t\t____err = lock(_lock);\t\t\t\t\\\n 456:\t\t}\t\t\t\t\t\t\t\\\n 457:\t\tif (!____err)\t\t\t\t\t\t\\\n 458:\t\t\tlock_acquired(\u0026(_lock)-\u003edep_map, _RET_IP_);\t\\\n 459:\t\t____err;\t\t\t\t\t\t\\\n 460:\t})\n 461:\t\n 462:\t#else /* CONFIG_LOCK_STAT */\n 463:\t\n 464:\t#define lock_contended(lockdep_map, ip) do {} while (0)\n 465:\t#define lock_acquired(lockdep_map, ip) do {} while (0)\n 466:\t\n 467:\t#define LOCK_CONTENDED(_lock, try, lock) \\\n 468:\t\tlock(_lock)\n 469:\t\n 470:\t#define LOCK_CONTENDED_RETURN(_lock, try, lock) \\\n 471:\t\tlock(_lock)\n 472:\t\n 473:\t#endif /* CONFIG_LOCK_STAT */\n 474:\t\n 475:\t#ifdef CONFIG_PROVE_LOCKING\n 476:\textern void print_irqtrace_events(struct task_struct *curr);\n 477:\t#else\n 478:\tstatic inline void print_irqtrace_events(struct task_struct *curr)\n 479:\t{\n 480:\t}\n 481:\t#endif\n 482:\t\n 483:\t/* Variable used to make lockdep treat read_lock() as recursive in selftests */\n 484:\t#ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS\n 485:\textern unsigned int force_read_lock_recursive;\n 486:\t#else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */\n 487:\t#define force_read_lock_recursive 0\n 488:\t#endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */\n 489:\t\n 490:\t#ifdef CONFIG_LOCKDEP\n 491:\textern bool read_lock_is_recursive(void);\n 492:\t#else /* CONFIG_LOCKDEP */\n 493:\t/* If !LOCKDEP, the value is meaningless */\n 494:\t#define read_lock_is_recursive() 0\n 495:\t#endif\n 496:\t\n 497:\t/*\n 498:\t * For trivial one-depth nesting of a lock-class, the following\n 499:\t * global define can be used. (Subsystems with multiple levels\n"
}

gemini-3.1-pro-preview

null

null

							input: 8484
							output: 36
							thoughts: 73
						

**Analyzing the Conditional Compilation of `rwsem_acquire_read`**

Okay, so I'm looking at this code and trying to understand how `rwsem_acquire_read` is handled. Hmm, I thought it was defined within a `#ifdef CONFIG_LOCKDEP` block, but that's not quite right. It looks like it's around line 538. I need to get a better handle on how this function is defined, conditionally.

Since `rwsem_acquire_read` is not within the `#ifdef CONFIG_LOCKDEP` block, I need to understand what happens when that feature *isn't* enabled. To do this, I'm going to jump into `include/linux/lockdep.h` to check the `#else` branch that's probably being used. Specifically, I'll focus on lines 350-400 of that header file. That should give me a good picture of the alternative definition and any related conditional compilation, so I can understand the complete context.

{
  "File": "include/linux/lockdep.h",
  "FirstLine": 350,
  "LineCount": 50
}

{
  "Contents": " 350:\t\t\tdo { (void)(name); (void)(key); } while (0)\n 351:\t# define lockdep_set_class(lock, key)\t\tdo { (void)(key); } while (0)\n 352:\t# define lockdep_set_class_and_name(lock, key, name) \\\n 353:\t\t\tdo { (void)(key); (void)(name); } while (0)\n 354:\t#define lockdep_set_class_and_subclass(lock, key, sub) \\\n 355:\t\t\tdo { (void)(key); } while (0)\n 356:\t#define lockdep_set_subclass(lock, sub)\t\tdo { } while (0)\n 357:\t\n 358:\t#define lockdep_set_novalidate_class(lock) do { } while (0)\n 359:\t#define lockdep_set_notrack_class(lock) do { } while (0)\n 360:\t\n 361:\t/*\n 362:\t * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP\n 363:\t * case since the result is not well defined and the caller should rather\n 364:\t * #ifdef the call himself.\n 365:\t */\n 366:\t\n 367:\t# define lockdep_reset()\t\tdo { debug_locks = 1; } while (0)\n 368:\t# define lockdep_free_key_range(start, size)\tdo { } while (0)\n 369:\t# define lockdep_sys_exit() \t\t\tdo { } while (0)\n 370:\t\n 371:\tstatic inline void lockdep_register_key(struct lock_class_key *key)\n 372:\t{\n 373:\t}\n 374:\t\n 375:\tstatic inline void lockdep_unregister_key(struct lock_class_key *key)\n 376:\t{\n 377:\t}\n 378:\t\n 379:\t#define lockdep_depth(tsk)\t(0)\n 380:\t\n 381:\t/*\n 382:\t * Dummy forward declarations, allow users to write less ifdef-y code\n 383:\t * and depend on dead code elimination.\n 384:\t */\n 385:\textern int lock_is_held(const void *);\n 386:\textern int lockdep_is_held(const void *);\n 387:\t#define lockdep_is_held_type(l, r)\t\t(1)\n 388:\t\n 389:\t#define lockdep_assert(c)\t\t\tdo { } while (0)\n 390:\t#define lockdep_assert_once(c)\t\t\tdo { } while (0)\n 391:\t\n 392:\t#define lockdep_assert_held(l)\t\t\t__assume_ctx_lock(l)\n 393:\t#define lockdep_assert_not_held(l)\t\tdo { (void)(l); } while (0)\n 394:\t#define lockdep_assert_held_write(l)\t\t__assume_ctx_lock(l)\n 395:\t#define lockdep_assert_held_read(l)\t\t__assume_shared_ctx_lock(l)\n 396:\t#define lockdep_assert_held_once(l)\t\tdo { (void)(l); } while (0)\n 397:\t#define lockdep_assert_none_held_once()\tdo { } while (0)\n 398:\t\n 399:\t#define lockdep_recursing(tsk)\t\t\t(0)\n"
}

gemini-3.1-pro-preview

null

null

							input: 9778
							output: 36
							thoughts: 23
						

Here's a summary of my thought process, tailored for an expert like you:

**Investigating `rwsem_acquire_read` Definition (No Lockdep)**

Okay, my initial instinct is to pinpoint the definition of `rwsem_acquire_read` under the condition where `CONFIG_LOCKDEP` is *not* enabled. I need to understand its behavior in this specific, simpler locking scenario. Since I'm working with a configuration-dependent function, the preprocessor directives will be the key. I'll be sifting through the relevant kernel headers and source files to locate where that function is actually implemented when lockdep isn't in play. I anticipate there might be a separate macro definition, or perhaps a direct inline function implementation. I'll be looking for something that clarifies exactly how the read acquire is handled in this less complex setup, especially regarding how the semaphore's internal state is updated. I need to grasp the low-level mechanics without the lock dependency tracking overhead.

{
  "Expression": "#define rwsem_acquire_read",
  "PathPrefix": "include/linux/lockdep.h"
}

{
  "Output": "include/linux/lockdep.h=519=do {\t\t\t\t\t\t\t\t\t\\\n--\ninclude/linux/lockdep.h-537-#define rwsem_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\ninclude/linux/lockdep.h:538:#define rwsem_acquire_read(l, s, t, i)\t\tlock_acquire_shared(l, s, t, NULL, i)\ninclude/linux/lockdep.h-539-#define rwsem_release(l, i)\t\t\tlock_release(l, i)\n"
}

gemini-3.1-pro-preview

null

null

							input: 10204
							output: 36
							thoughts: 45
						

Here's my thought process, as if I were analyzing that code:

**Diving into the `rwsem_acquire_read` Definition**

Okay, so I need to understand where `rwsem_acquire_read` is defined. The hint says line 538, but I'm being thorough, so I want to confirm the surrounding context, and check if any conditional compilation macros are involved. I'll take a look at lines 500-550. Let's see what the code around that area reveals. It's a quick way to get the lay of the land, understand any surrounding definitions, and determine if `CONFIG_LOCKDEP` has any bearing on its actual declaration. No need to skim, I need full context of the code. This is essential for a complete understanding of how it's being used. Let's check those lines.

{
  "File": "include/linux/lockdep.h",
  "FirstLine": 500,
  "LineCount": 50
}

{
  "Contents": " 500:\t * of nesting should define their own lock-nesting subclasses.)\n 501:\t */\n 502:\t#define SINGLE_DEPTH_NESTING\t\t\t1\n 503:\t\n 504:\t/*\n 505:\t * Map the dependency ops to NOP or to real lockdep ops, depending\n 506:\t * on the per lock-class debug mode:\n 507:\t */\n 508:\t\n 509:\t#define lock_acquire_exclusive(l, s, t, n, i)\t\tlock_acquire(l, s, t, 0, 1, n, i)\n 510:\t#define lock_acquire_shared(l, s, t, n, i)\t\tlock_acquire(l, s, t, 1, 1, n, i)\n 511:\t#define lock_acquire_shared_recursive(l, s, t, n, i)\tlock_acquire(l, s, t, 2, 1, n, i)\n 512:\t\n 513:\t#define spin_acquire(l, s, t, i)\t\tlock_acquire_exclusive(l, s, t, NULL, i)\n 514:\t#define spin_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\n 515:\t#define spin_release(l, i)\t\t\tlock_release(l, i)\n 516:\t\n 517:\t#define rwlock_acquire(l, s, t, i)\t\tlock_acquire_exclusive(l, s, t, NULL, i)\n 518:\t#define rwlock_acquire_read(l, s, t, i)\t\t\t\t\t\\\n 519:\tdo {\t\t\t\t\t\t\t\t\t\\\n 520:\t\tif (read_lock_is_recursive())\t\t\t\t\t\\\n 521:\t\t\tlock_acquire_shared_recursive(l, s, t, NULL, i);\t\\\n 522:\t\telse\t\t\t\t\t\t\t\t\\\n 523:\t\t\tlock_acquire_shared(l, s, t, NULL, i);\t\t\t\\\n 524:\t} while (0)\n 525:\t\n 526:\t#define rwlock_release(l, i)\t\t\tlock_release(l, i)\n 527:\t\n 528:\t#define seqcount_acquire(l, s, t, i)\t\tlock_acquire_exclusive(l, s, t, NULL, i)\n 529:\t#define seqcount_acquire_read(l, s, t, i)\tlock_acquire_shared_recursive(l, s, t, NULL, i)\n 530:\t#define seqcount_release(l, i)\t\t\tlock_release(l, i)\n 531:\t\n 532:\t#define mutex_acquire(l, s, t, i)\t\tlock_acquire_exclusive(l, s, t, NULL, i)\n 533:\t#define mutex_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\n 534:\t#define mutex_release(l, i)\t\t\tlock_release(l, i)\n 535:\t\n 536:\t#define rwsem_acquire(l, s, t, i)\t\tlock_acquire_exclusive(l, s, t, NULL, i)\n 537:\t#define rwsem_acquire_nest(l, s, t, n, i)\tlock_acquire_exclusive(l, s, t, n, i)\n 538:\t#define rwsem_acquire_read(l, s, t, i)\t\tlock_acquire_shared(l, s, t, NULL, i)\n 539:\t#define rwsem_release(l, i)\t\t\tlock_release(l, i)\n 540:\t\n 541:\t#define lock_map_acquire(l)\t\t\tlock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)\n 542:\t#define lock_map_acquire_try(l)\t\t\tlock_acquire_exclusive(l, 0, 1, NULL, _THIS_IP_)\n 543:\t#define lock_map_acquire_read(l)\t\tlock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)\n 544:\t#define lock_map_acquire_tryread(l)\t\tlock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)\n 545:\t#define lock_map_release(l)\t\t\tlock_release(l, _THIS_IP_)\n 546:\t#define lock_map_sync(l)\t\t\tlock_sync(l, 0, 0, 1, NULL, _THIS_IP_)\n 547:\t\n 548:\t#ifdef CONFIG_PROVE_LOCKING\n 549:\t# define might_lock(lock)\t\t\t\t\t\t\\\n"
}

gemini-3.1-pro-preview

null

null

							input: 11732
							output: 33
							thoughts: 53
						

Here's my take on the thought process, summarized as you requested:

**Deconstructing a Lock Acquisition Call**

Okay, let's break this down. I see `lock_acquire_shared` is defined using a more general function call: `lock_acquire(l, s, t, 1, 1, n, i)`. Nothing surprising there - makes sense to have a core function. But hold on... if `CONFIG_LOCKDEP` is disabled, what *exactly* does `lock_acquire` *become*? I need to understand how the system behaves under different compilation scenarios. Is it a simple inline function, or does it resolve to something more primitive? Are any debugging aids disabled? I need to understand this to have any confidence in how this lock is behaving.

{
  "Expression": "#define lock_acquire",
  "PathPrefix": "include/linux/lockdep.h"
}

{
  "Output": "include/linux/lockdep.h=442=do {\t\t\t\t\t\t\t\t\\\n--\ninclude/linux/lockdep.h-464-#define lock_contended(lockdep_map, ip) do {} while (0)\ninclude/linux/lockdep.h:465:#define lock_acquired(lockdep_map, ip) do {} while (0)\ninclude/linux/lockdep.h-466-\n--\ninclude/linux/lockdep.h=491=extern bool read_lock_is_recursive(void);\n--\ninclude/linux/lockdep.h-508-\ninclude/linux/lockdep.h:509:#define lock_acquire_exclusive(l, s, t, n, i)\t\tlock_acquire(l, s, t, 0, 1, n, i)\ninclude/linux/lockdep.h:510:#define lock_acquire_shared(l, s, t, n, i)\t\tlock_acquire(l, s, t, 1, 1, n, i)\ninclude/linux/lockdep.h:511:#define lock_acquire_shared_recursive(l, s, t, n, i)\tlock_acquire(l, s, t, 2, 1, n, i)\ninclude/linux/lockdep.h-512-\n"
}

gemini-3.1-pro-preview

null

null

							input: 12311
							output: 32
							thoughts: 13
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Tracing `lock_acquire`'s Origin**

Okay, so I need to understand this `lock_acquire` function better. Where exactly is it defined within the codebase? I need to trace its origin to understand its implementation details and potential implications for concurrency. Is it a system call, a kernel function, a userspace library, or perhaps a custom implementation within this specific project? My immediate approach would be to use whatever tools are available: grep, find, the symbol browser in my IDE, or even a basic source code search. I'm looking for the definitive declaration – the header file, the actual source code where it's defined and what the surrounding context says. I need to figure out its prototype as well, for what arguments does it expect, and what does it return. The next step will be to check for any relevant header files or include paths to locate the definition. Ultimately, I need the concrete code to analyze its behavior. I anticipate needing to understand any synchronization primitives used internally and how it integrates with the overall locking scheme.

{
  "Expression": "define lock_acquire",
  "PathPrefix": "include/linux/lockdep.h"
}

{
  "Output": "include/linux/lockdep.h=332=static inline void lockdep_set_selftest_task(struct task_struct *task)\n--\ninclude/linux/lockdep.h-335-\ninclude/linux/lockdep.h:336:# define lock_acquire(l, s, t, r, c, n, i)\tdo { } while (0)\ninclude/linux/lockdep.h-337-# define lock_release(l, i)\t\t\tdo { } while (0)\n--\ninclude/linux/lockdep.h=442=do {\t\t\t\t\t\t\t\t\\\n--\ninclude/linux/lockdep.h-464-#define lock_contended(lockdep_map, ip) do {} while (0)\ninclude/linux/lockdep.h:465:#define lock_acquired(lockdep_map, ip) do {} while (0)\ninclude/linux/lockdep.h-466-\n--\ninclude/linux/lockdep.h=491=extern bool read_lock_is_recursive(void);\n--\ninclude/linux/lockdep.h-508-\ninclude/linux/lockdep.h:509:#define lock_acquire_exclusive(l, s, t, n, i)\t\tlock_acquire(l, s, t, 0, 1, n, i)\ninclude/linux/lockdep.h:510:#define lock_acquire_shared(l, s, t, n, i)\t\tlock_acquire(l, s, t, 1, 1, n, i)\ninclude/linux/lockdep.h:511:#define lock_acquire_shared_recursive(l, s, t, n, i)\tlock_acquire(l, s, t, 2, 1, n, i)\ninclude/linux/lockdep.h-512-\n"
}

gemini-3.1-pro-preview

null

null

							input: 13040
							output: 113
							thoughts: 990
						

**Analysis of the Proposed Patch**

Okay, so looking at this patch, my initial thought was that the changes to `rwsem_acquire_read` seemed purely related to lockdep annotations, given the `CONFIG_LOCKDEP` context. And the fact that when lockdep is disabled, `lock_acquire` is a no-op macro, that reinforced this.

The code snippets highlighted a refactoring to replace a direct flag check with a local `nowait` variable. The key change that caught my eye was passing this `nowait` variable to `rwsem_acquire_read`. This looked to be about conveying whether a "trylock" was attempted, a critical piece of info for lockdep's tracking.

Then, I went deeper. I verified that `rwsem_acquire_read` indeed maps to a series of `lock_acquire` calls. And the parameter being modified is the "trylock" parameter of that `lock_acquire` chain. If `nowait` is true, a trylock is indicated to lockdep; otherwise it's a regular lock.

The important point is this parameter change only impacts how lockdep monitors the locking behavior. The *actual* execution path, the *actual* locking behavior, isn't modified. `blk_try_enter_queue` isn't touched, nor are any of the underlying locking primitives directly changed by any of this.

Therefore, this patch boils down to these modifications:
1.  Extracting the `REQ_NOWAIT` flag into a `nowait` boolean for readability.
2.  Using the `nowait` boolean variable in conditional statements.
3.  Passing `nowait` to `rwsem_acquire_read` which, in turn, impacts lockdep annotation.

Given the nature of the changes, this patch doesn't introduce any new functional behavior into the kernel that should be prioritized for fuzzing. The changes are about the lockdep tracking, not about any functional modification. I'll flag this as WorthFuzzing=false.

{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch only refactors the extraction of the 'nowait' flag into a local variable and passes it as the 'trylock' parameter to rwsem_acquire_read(). Since rwsem_acquire_read() is purely a lockdep annotation macro that expands to nothing when CONFIG_LOCKDEP is disabled, this patch does not functionally alter the execution flow of the kernel and is not worth fuzzing.",
  "WorthFuzzing": false
}

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only refactors the extraction of the 'nowait' flag into a local variable and passes it as the 'trylock' parameter to rwsem_acquire_read(). Since rwsem_acquire_read() is purely a lockdep annotation macro that expands to nothing when CONFIG_LOCKDEP is disabled, this patch does not functionally alter the execution flow of the kernel and is not worth fuzzing.",
  "WorthFuzzing": false
}