AI Trajectory

Trajectory: (Expand/Collapse All)
Seq	Timestamp	Type	Name	Duration
0/0	2026/09/25 11:20	flow	patch-triage	2m Args: null Results: { "EnableConfigs": [ "LIBNVDIMM", "BLK_DEV_PMEM" ], "FocusSymbols": [ "pmem_mkpage_present", "__pmem_clear_poison", "pmem_clear_poison", "pmem_recovery_write", "pmem_do_write", "pmem_submit_bio" ], "KMSANReasoning": "The patch is a cleanup/refactoring that removes a driver-specific wrapper (`test_and_clear_pmem_poison`) in `drivers/nvdimm/pmem.h` and instead provides the standard `TESTSCFLAG_FALSE(HWPoison, hwpoison)` fallback in `include/linux/page-flags.h` for when `CONFIG_MEMORY_FAILURE` is disabled. This allows `drivers/nvdimm/pmem.c` to call `TestClearPageHWPoison(page)` directly.\n\nThis change does not allocate or copy any memory, does not modify any data structures passed to userspace or across security boundaries, and does not alter variable initialization or introduce uninitialized memory reads. Consequently, there are no uninitialized memory risks or info-leak hazards that would require KMSAN detection. Standard test/sanitizer coverage (e.g. KASAN) is sufficient.", "NeedsKMSAN": false, "Reasoning": "The patch introduces TESTSCFLAG_FALSE(HWPoison, hwpoison) to core memory management (include/linux/page-flags.h) for !CONFIG_MEMORY_FAILURE builds, and removes a custom wrapper in pmem.h by switching callers in drivers/nvdimm/pmem.c (pmem_mkpage_present) directly to TestClearPageHWPoison. The modified code resides in core mm headers and the PMEM block driver, which is reachable in virtualized environments (QEMU/virtio-pmem, memmap, ACPI NFIT). Refactoring helper abstractions in reachable code paths warrants fuzzing.", "WorthFuzzing": true }
1/1	2026/09/25 11:20	action	read-patch-diff	0m Args: null Results: { "PatchDiff": "commit 3b682ae789c01f7ba36ce00392c9724354d94fc6\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Fri Sep 25 11:20:43 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c\nindex 30a51c365ce8b..5fb86595e8bd7 100644\n--- a/drivers/nvdimm/pmem.c\n+++ b/drivers/nvdimm/pmem.c\n@@ -80,7 +80,7 @@ static void pmem_mkpage_present(struct pmem_device pmem, phys_addr_t offset,\n \t\t here since we're in the driver I/O path and\n \t\t * outstanding I/O requests pin the dev_pagemap.\n \t\t /\n-\t\tif (test_and_clear_pmem_poison(page))\n+\t\tif (TestClearPageHWPoison(page))\n \t\t\tclear_mce_nospec(pfn);\n \t}\n }\ndiff --git a/drivers/nvdimm/pmem.h b/drivers/nvdimm/pmem.h\nindex a48509f901968..76870505dd797 100644\n--- a/drivers/nvdimm/pmem.h\n+++ b/drivers/nvdimm/pmem.h\n@@ -1,7 +1,6 @@\n / SPDX-License-Identifier: GPL-2.0 /\n #ifndef __NVDIMM_PMEM_H__\n #define __NVDIMM_PMEM_H__\n-#include \u003clinux/page-flags.h\u003e\n #include \u003clinux/badblocks.h\u003e\n #include \u003clinux/memremap.h\u003e\n #include \u003clinux/types.h\u003e\n@@ -31,15 +30,4 @@ long __pmem_direct_access(struct pmem_device pmem, pgoff_t pgoff,\n \t\tlong nr_pages, enum dax_access_mode mode, void *kaddr,\n \t\tunsigned long pfn);\n \n-#ifdef CONFIG_MEMORY_FAILURE\n-static inline bool test_and_clear_pmem_poison(struct page page)\n-{\n-\treturn TestClearPageHWPoison(page);\n-}\n-#else\n-static inline bool test_and_clear_pmem_poison(struct page page)\n-{\n-\treturn false;\n-}\n-#endif\n #endif /* __NVDIMM_PMEM_H__ */\ndiff --git a/include/linux/page-flags.h b/include/linux/page-flags.h\nindex ae2ebaed6d4d9..3dc79c0c5adf0 100644\n--- a/include/linux/page-flags.h\n+++ b/include/linux/page-flags.h\n@@ -655,6 +655,7 @@ TESTSCFLAG(HWPoison, hwpoison, PF_ANY)\n #define __PG_HWPOISON (1UL \u003c\u003c PG_hwpoison)\n #else\n PAGEFLAG_FALSE(HWPoison, hwpoison)\n+TESTSCFLAG_FALSE(HWPoison, hwpoison)\n #define __PG_HWPOISON 0\n #endif\n \n" }
2/1	2026/09/25 11:20	agent	patch-evaluator	2m Model: core Args: null Results: { "EnableConfigs": [ "LIBNVDIMM", "BLK_DEV_PMEM" ], "FocusSymbols": [ "pmem_mkpage_present", "__pmem_clear_poison", "pmem_clear_poison", "pmem_recovery_write", "pmem_do_write", "pmem_submit_bio" ], "Reasoning": "The patch introduces TESTSCFLAG_FALSE(HWPoison, hwpoison) to core memory management (include/linux/page-flags.h) for !CONFIG_MEMORY_FAILURE builds, and removes a custom wrapper in pmem.h by switching callers in drivers/nvdimm/pmem.c (pmem_mkpage_present) directly to TestClearPageHWPoison. The modified code resides in core mm headers and the PMEM block driver, which is reachable in virtualized environments (QEMU/virtio-pmem, memmap, ACPI NFIT). Refactoring helper abstractions in reachable code paths warrants fuzzing.", "WorthFuzzing": true } Instruction: You are an expert Linux kernel maintainer and security engineer. Your job is to review a provided patch series and evaluate whether it warrants fuzzing with syzkaller. IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in your workspace. Do NOT rely on internal assumptions. You must actively use your code access tools to inspect the actual source code, callers, and surrounding context. ================================================================================ 1. CORE TRIAGE PHILOSOPHY ================================================================================ The goal of patch fuzzing is to discover crashes, regressions, exposed latent bugs, and newly triggered assertions introduced by the patch series. - REACHABILITY IS THE PRIMARY GATE: Fuzzing can only discover bugs in code that can actually execute in standard virtualized environments (GCE or QEMU, utilizing software-emulated devices like USB gadgets, netdev, tun/tap). If the modified code is structurally unreachable (see Section 2), it MUST NOT be fuzzed, regardless of whether it adds assertions or complex logic. - DO NOT BLINDLY TRUST "NO FUNCTIONAL CHANGE" (NFCI) OR "REFACTORING" CLAIMS: Patch authors routinely label changes as "cleanups", "refactorings", or state "No functional change intended". Do NOT take these claims at face value. Code refactorings that rearrange logic, introduce helper functions, or alter state management in core subsystems frequently introduce subtle semantic shifts or uncover latent kernel bugs. If reachable executable code is modified or refactored, it MUST be fuzzed. - NEW OR MODIFIED ASSERTIONS IN REACHABLE CODE MUST BE FUZZED: When a patch introduces or modifies runtime checks or assertions (e.g., WARN_ON, VM_WARN_ON, BUG_ON, lockdep_assert) in reachable code paths, it enforces new or stricter invariants. Even if the author believes the invariant always holds, fuzzing is essential to verify whether an unusual sequence of operations can violate it. ================================================================================ 2. WHEN TO RETURN WorthFuzzing=false (NEGATIVE CRITERIA) ================================================================================ Return WorthFuzzing=false ONLY IF all modified code falls strictly into one or more of these categories: - Non-kernel and non-executable changes: * Modifications to Documentation/, comments, or spelling fixes. * User-space directories, self-tests, samples, or scripts (e.g., tools/, samples/, scripts/, usr/) that do not affect the compiled kernel image (vmlinux) or kernel modules. * Purely decorative logging (e.g., message strings in pr_err, printk, dev_info) or tracepoints that do not alter control flow or data structures. * Build system or Kconfig changes that do not alter compiled C logic. - Structurally unreachable hardware: * Vendor-specific PCIe switches, SmartNICs, or GPU drivers (e.g., mlxsw, pds_core, qed, ionic, amdgpu) requiring physical ASIC/PCIe cards not emulated in standard QEMU. - Unreachable execution paths: * Driver teardown callbacks (.remove, .shutdown, pci_unregister_driver) executed only during physical PCI hot-unplug or manual sysfs driver unbinding. * Code paths exclusive to architectures other than the target architecture. ================================================================================ 3. WHEN TO RETURN WorthFuzzing=true (POSITIVE CRITERIA) ================================================================================ Return WorthFuzzing=true whenever the patch touches reachable executable code, including: - Core Subsystems: * Any logic modifications in memory management (mm/), synchronization/locking (kernel/locking/), BPF, scheduler, core networking, VFS, or syscall handling. - Refactorings and Code Cleanups: * Any restructuring of reachable data structures, helper abstractions, or algorithm flows. - Runtime Assertions and Defensive Checks: * Any introduction or alteration of assertions (WARN_ON, VM_WARN_ON, BUG_ON, etc.) in reachable paths. - Reachable Drivers and Protocols: Drivers accessible via virtual buses (virtio, USB gadget, loopback, netlink, binder, sockets, etc.). ================================================================================ 4. EXTRACTING FocusSymbols (PREVENTING DILUTION) ================================================================================ When WorthFuzzing=true, you must extract specific kernel functions into FocusSymbols to guide the fuzzer: - AVOID UBIQUITOUS LIFECYCLE HOT-PATHS: Do NOT list generic, ubiquitous functions called by almost every program in the corpus (including, but not limited to: general memory allocators and deallocators, page fault and trap handlers, or core synchronization primitives; this is not an exhaustive list). Listing ubiquitous functions causes the fuzzer to classify thousands of unrelated tests as "focused", which severely dilutes fuzzing effort away from the actual changes. - TARGET SPECIFIC FEATURE LOGIC AND ENTRYPOINTS: List functions that specifically implement the logic being added or altered, or direct API entrypoints for the subsystem feature under review. - HANDLING STATIC INLINE FUNCTIONS IN HEADERS (.h): Compiler-inlined static functions (such as static inlines in mm/.h or include/linux/.h) lack distinct symbol addresses in vmlinux and cannot be targeted directly by symbol coverage filters. If the changes are primarily in static inline helpers, identify non-static, feature-specific caller functions in .c files that exercise them (avoiding ubiquitous lifecycle wrappers). ================================================================================ 5. IDENTIFYING EnableConfigs ================================================================================ Identify any specific CONFIG_ options required to properly compile and reach the modified code: - Inspect Kconfig files and #ifdef guards; do not make assumptions. - Check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed. - Strip any '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: Target architecture: amd64 For your convenience, here is the diff of the changes: commit 3b682ae789c01f7ba36ce00392c9724354d94fc6 Author: syz-cluster <triage@syzkaller.com> Date: Fri Sep 25 11:20:43 2026 +0000 syz-cluster: applied patch under review diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 30a51c365ce8b..5fb86595e8bd7 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -80,7 +80,7 @@ static void pmem_mkpage_present(struct pmem_device pmem, phys_addr_t offset, here since we're in the driver I/O path and * outstanding I/O requests pin the dev_pagemap. / - if (test_and_clear_pmem_poison(page)) + if (TestClearPageHWPoison(page)) clear_mce_nospec(pfn); } } diff --git a/drivers/nvdimm/pmem.h b/drivers/nvdimm/pmem.h index a48509f901968..76870505dd797 100644 --- a/drivers/nvdimm/pmem.h +++ b/drivers/nvdimm/pmem.h @@ -1,7 +1,6 @@ / SPDX-License-Identifier: GPL-2.0 / #ifndef __NVDIMM_PMEM_H__ #define __NVDIMM_PMEM_H__ -#include <linux/page-flags.h> #include <linux/badblocks.h> #include <linux/memremap.h> #include <linux/types.h> @@ -31,15 +30,4 @@ long __pmem_direct_access(struct pmem_device pmem, pgoff_t pgoff, long nr_pages, enum dax_access_mode mode, void *kaddr, unsigned long pfn); -#ifdef CONFIG_MEMORY_FAILURE -static inline bool test_and_clear_pmem_poison(struct page page) -{ - return TestClearPageHWPoison(page); -} -#else -static inline bool test_and_clear_pmem_poison(struct page page) -{ - return false; -} -#endif #endif /* __NVDIMM_PMEM_H__ */ diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index ae2ebaed6d4d9..3dc79c0c5adf0 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -655,6 +655,7 @@ TESTSCFLAG(HWPoison, hwpoison, PF_ANY) #define __PG_HWPOISON (1UL << PG_hwpoison) #else PAGEFLAG_FALSE(HWPoison, hwpoison) +TESTSCFLAG_FALSE(HWPoison, hwpoison) #define __PG_HWPOISON 0 #endif
3/2	2026/09/25 11:20	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 3415 output: 21 thoughts: 304 Thoughts: Analyzing the Proposed Patch: NVDIMM Poison Handling Okay, so I'm looking at this patch and it seems pretty straightforward on the surface, but let's dig into the details. I see that this modification is focused on how we're handling hardware-poisoned pages within the NVDIMM driver, specifically the persistent memory part of it. First, I see a change in `drivers/nvdimm/pmem.c`. Specifically, the `pmem_mkpage_present` function is being updated. It appears we're replacing a call to `test_and_clear_pmem_poison(page)` with `TestClearPageHWPoison(page)`. My immediate thought is that this likely simplifies the logic or consolidates a function, but I need to understand why. Next, I see that the header `drivers/nvdimm/pmem.h` is changing. The function `test_and_clear_pmem_poison(struct page *page)` is being removed entirely. This function appears to have been an ifdef wrapper around `CONFIG_MEMORY_FAILURE`, which makes me think that the change could affect what happens with error handling in systems which have the `MEMORY_FAILURE` config option enabled vs disabled. Lastly, I see the change in `include/linux/page-flags.h`. I recognize this file as the central location for defining page flags. The key here is the conditional compilation based on `CONFIG_MEMORY_FAILURE`. The original code used an ifdef that would define the `HWPoison` flag with either `TESTSCFLAG` or `PAGEFLAG_FALSE`. The ifdef also defined `__PG_HWPOISON` as either `(1UL << PG_hwpoison)` or `0`. The changes here are removing the `PAGEFLAG_FALSE` declaration and adding a `TESTSCFLAG_FALSE`, and the important thing here is the change to the `TESTSCFLAG_FALSE` macro, which is new to me. My immediate assumption is that this patch is refining the way we test for and clear hardware poison on pages, with the underlying goal of optimizing or simplifying the code. The fact that the ifdef is there makes me think that the patch might be about improving behavior under different configurations. I know I need to delve further and check the definitions of the new and existing macros, especially `TestClearPageHWPoison` and `TESTSCFLAG`, to fully understand what's happening. I should probably use `read-file` or `grepper` to see how those macros are defined and used.
4/2	2026/09/25 11:20	tool	grepper	0m Args: { "Expression": "pmem_mkpage_present" } Results: { "Output": "drivers/nvdimm/pmem.c=58=static phys_addr_t to_offset(struct pmem_device pmem, sector_t sector)\n--\ndrivers/nvdimm/pmem.c-62-\ndrivers/nvdimm/pmem.c:63:static void pmem_mkpage_present(struct pmem_device pmem, phys_addr_t offset,\ndrivers/nvdimm/pmem.c-64-\t\tunsigned int len)\n--\ndrivers/nvdimm/pmem.c=97=static long __pmem_clear_poison(struct pmem_device *pmem,\n--\ndrivers/nvdimm/pmem.c-103-\tif (cleared \u003e 0) {\ndrivers/nvdimm/pmem.c:104:\t\tpmem_mkpage_present(pmem, offset, cleared);\ndrivers/nvdimm/pmem.c-105-\t\tarch_invalidate_pmem(pmem-\u003evirt_addr + offset, len);\n" }
5/2	2026/09/25 11:20	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 4545 output: 37 thoughts: 22 Thoughts: Here's my attempt at summarizing the thought process, tailored for an expert audience: Diving into Page Flags Okay, time to get my hands dirty. I need to take a look at the core of how the kernel manages physical pages. I'm going to navigate directly into `include/linux/page-flags.h`, specifically focusing on the code around line 655. That's where I expect to find the detailed definitions and usage of the various page flags – the bitfields that control page behavior, tracking things like dirty state, referenced status, mapping information, and NUMA node assignment. I'm anticipating that this section will shed light on how the kernel optimizes page allocation, reclaim, and management, or perhaps show how different memory zones and architectures interact with the underlying flags. It's time to refresh my memory and maybe find a subtle nuance about how the flags are used!
6/2	2026/09/25 11:20	tool	read-file	0m Args: { "File": "include/linux/page-flags.h", "FirstLine": 645, "LineCount": 25 } Results: { "Contents": " 645:\t#else\n 646:\tFOLIO_FLAG_FALSE(mlocked)\n 647:\t\t__FOLIO_CLEAR_FLAG_NOOP(mlocked)\n 648:\t\tFOLIO_TEST_CLEAR_FLAG_FALSE(mlocked)\n 649:\t\tFOLIO_TEST_SET_FLAG_FALSE(mlocked)\n 650:\t#endif\n 651:\t\n 652:\t#ifdef CONFIG_MEMORY_FAILURE\n 653:\tPAGEFLAG(HWPoison, hwpoison, PF_ANY)\n 654:\tTESTSCFLAG(HWPoison, hwpoison, PF_ANY)\n 655:\t#define __PG_HWPOISON (1UL \u003c\u003c PG_hwpoison)\n 656:\t#else\n 657:\tPAGEFLAG_FALSE(HWPoison, hwpoison)\n 658:\tTESTSCFLAG_FALSE(HWPoison, hwpoison)\n 659:\t#define __PG_HWPOISON 0\n 660:\t#endif\n 661:\t\n 662:\t#ifdef CONFIG_PAGE_IDLE_FLAG\n 663:\t#ifdef CONFIG_64BIT\n 664:\tFOLIO_TEST_FLAG(young, FOLIO_HEAD_PAGE)\n 665:\tFOLIO_SET_FLAG(young, FOLIO_HEAD_PAGE)\n 666:\tFOLIO_TEST_CLEAR_FLAG(young, FOLIO_HEAD_PAGE)\n 667:\tFOLIO_FLAG(idle, FOLIO_HEAD_PAGE)\n 668:\t#endif\n 669:\t/* See page_idle.h for !64BIT workaround */\n" }
7/2	2026/09/25 11:20	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 5225 output: 19 thoughts: 25 Thoughts: Here's my attempt at summarizing the thought process, tailored for an expert audience: Investigating TESTSCFLAG_FALSE Okay, so I'm diving into `include/linux/page-flags.h` to refresh my memory on what `TESTSCFLAG_FALSE` actually does. I suspect it's a macro or definition related to testing set/clear conditions in the page flags, probably some kind of pre-processor construct for efficient checks. I need to understand its exact semantics – whether it's simply a boolean false literal, a bitmask, or potentially something more complex, like a comparison operation that always evaluates to false for flag checks. Knowing precisely what it expands to will inform how it's used within the various kernel subsystems; especially if it's potentially architecturally sensitive or could introduce performance bottlenecks. I need to avoid making assumptions, it's always worth double-checking. Time to crack open the include file and see what's what.
8/2	2026/09/25 11:21	tool	grepper	0m Args: { "Expression": "TESTSCFLAG_FALSE" } Results: { "Output": "include/linux/page-flags.h=537=static inline int TestClearPage##uname(struct page *page) { return 0; }\n--\ninclude/linux/page-flags.h-541-\ninclude/linux/page-flags.h:542:#define TESTSCFLAG_FALSE(uname, lname)\t\t\t\t\t\\\ninclude/linux/page-flags.h-543-\tTESTSETFLAG_FALSE(uname, lname) TESTCLEARFLAG_FALSE(uname, lname)\n--\ninclude/linux/page-flags.h=657=PAGEFLAG_FALSE(HWPoison, hwpoison)\ninclude/linux/page-flags.h:658:TESTSCFLAG_FALSE(HWPoison, hwpoison)\ninclude/linux/page-flags.h-659-#define __PG_HWPOISON 0\n" }
9/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 5681 output: 35 thoughts: 872 Thoughts: Fuzzing Analysis of NVDIMM/PMEM Poisoning Code Okay, so I'm looking at this patch and it seems to be refactoring some memory poisoning code, specifically around `HWPoison`. The key change is the introduction of `TESTSCFLAG_FALSE(HWPoison, hwpoison)`, which simplifies how we clear hardware poison on pages, essentially removing a conditional `test_and_clear_pmem_poison` function in `pmem.h`. This now allows for a direct call to `TestClearPageHWPoison(page)`. My initial thought is to assess the fuzzing implications. Is this code even reachable? The triage guidelines are pretty clear: reachability is the primary gate for fuzzing. If it's not reachable, we don't need to fuzz it. That's the baseline. I immediately start questioning whether pmem/nvdimm is emulatable or fuzzed in standard environments like QEMU or syzkaller. Can we reliably trigger this code path? I need to determine if pmem/nvdimm are reachable. Syzkaller fuzzes nvdimm/pmem. I'm going to consult the triage guidelines - they're crucial. They make it clear: if reachable executable code is modified, we fuzz. If there are new or modified assertions in reachable code, we fuzz. The guidelines are pretty black and white about this. Okay, let's break this down. `include/linux/page-flags.h` is where that `TESTSCFLAG_FALSE` macro resides, and that's core memory management territory. The patch also modifies `drivers/nvdimm/pmem.c`. That's a red flag. This seems like it's touching reachable, executable code. Now I need to address the reachability of pmem. I know QEMU supports NVDIMM and PMEM emulation using `-machine ...,nvdimm=on`, `memdisk` or memmap/ACPI NFIT configurations. My understanding is that this is the common way to test this functionality. I also know that syzkaller likely has support as well. So I need to check what configurations are needed to build `drivers/nvdimm/pmem.c`. I will check both `drivers/nvdimm/Kconfig` and `drivers/nvdimm/Makefile` files.
10/2	2026/09/25 11:21	tool	grepper	0m Args: { "Expression": "obj-\\$\\(CONFIG.pmem\\.o", "PathPrefix": "drivers/nvdimm" } Results:* { "Output": "drivers/nvdimm/Makefile=2=obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o\ndrivers/nvdimm/Makefile:3:obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o\ndrivers/nvdimm/Makefile-4-obj-$(CONFIG_ND_BTT) += nd_btt.o\ndrivers/nvdimm/Makefile=5=obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o\ndrivers/nvdimm/Makefile:6:obj-$(CONFIG_OF_PMEM) += of_pmem.o\ndrivers/nvdimm/Makefile:7:obj-$(CONFIG_VIRTIO_PMEM) += virtio_pmem.o nd_virtio.o\ndrivers/nvdimm/Makefile-8-obj-$(CONFIG_RAMDAX) += ramdax.o\n" }
11/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 7320 output: 29 thoughts: 13 Thoughts: Okay, here's my summary, tailored for an expert audience, as if I'm thinking these things myself: Diving into the Makefile for nd_pmem Alright, time to get my hands dirty and understand how this `nd_pmem` module is actually built. First things first, I need to check out its `Makefile`. Gotta see what the build process looks like – what flags are being used, what dependencies are present, how the object files are linked, and crucially, are there any interesting optimizations or specific configurations for persistent memory integration. I want to identify the key components. Does it utilize specific libraries or headers for pmem operations? Are there conditional compilation steps based on the target architecture or the presence of specific pmem features? I'm hoping to quickly grasp the high-level build flow and then maybe zoom in on any areas of concern or interest. This `Makefile` is the blueprint, and I need to understand its construction to truly understand the module. Let's get to it.
12/2	2026/09/25 11:21	tool	grepper	0m Args: { "Expression": "nd_pmem", "PathPrefix": "drivers/nvdimm" } Results: { "Output": "drivers/nvdimm/Makefile=2=obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o\ndrivers/nvdimm/Makefile:3:obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o\ndrivers/nvdimm/Makefile-4-obj-$(CONFIG_ND_BTT) += nd_btt.o\n--\ndrivers/nvdimm/Makefile=8=obj-$(CONFIG_RAMDAX) += ramdax.o\ndrivers/nvdimm/Makefile-9-\ndrivers/nvdimm/Makefile:10:nd_pmem-y := pmem.o\ndrivers/nvdimm/Makefile-11-\n--\ndrivers/nvdimm/bus.c=933=void wait_nvdimm_bus_probe_idle(struct device dev)\n--\ndrivers/nvdimm/bus.c-948-\ndrivers/nvdimm/bus.c:949:static int nd_pmem_forget_poison_check(struct device dev, void data)\ndrivers/nvdimm/bus.c-950-{\n--\ndrivers/nvdimm/bus.c=990=static int nd_ns_forget_poison_check(struct device dev, void data)\ndrivers/nvdimm/bus.c-991-{\ndrivers/nvdimm/bus.c:992:\treturn device_for_each_child(dev, data, nd_pmem_forget_poison_check);\ndrivers/nvdimm/bus.c-993-}\n--\ndrivers/nvdimm/dimm_devs.c=693=static unsigned long dpa_align(struct nd_region nd_region)\n--\ndrivers/nvdimm/dimm_devs.c-708-/*\ndrivers/nvdimm/dimm_devs.c:709: nd_pmem_max_contiguous_dpa - For the given dimm+region, return the max\ndrivers/nvdimm/dimm_devs.c-710- \t\t\t contiguous unallocated dpa range.\n--\ndrivers/nvdimm/dimm_devs.c-716- /\ndrivers/nvdimm/dimm_devs.c:717:resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region nd_region,\ndrivers/nvdimm/dimm_devs.c-718-\t\t\t\t\t struct nd_mapping nd_mapping)\n--\ndrivers/nvdimm/dimm_devs.c-754-/*\ndrivers/nvdimm/dimm_devs.c:755: nd_pmem_available_dpa - for the given dimm+region account unallocated dpa\ndrivers/nvdimm/dimm_devs.c-756- * @nd_mapping: container of dpa-resource-root + labels\n--\ndrivers/nvdimm/dimm_devs.c-763- /\ndrivers/nvdimm/dimm_devs.c:764:resource_size_t nd_pmem_available_dpa(struct nd_region nd_region,\ndrivers/nvdimm/dimm_devs.c-765-\t\t\t\t struct nd_mapping nd_mapping)\n--\ndrivers/nvdimm/label.c=1023=static int del_labels(struct nd_mapping nd_mapping, uuid_t uuid)\n--\ndrivers/nvdimm/label.c-1067-\ndrivers/nvdimm/label.c:1068:int nd_pmem_namespace_label_update(struct nd_region nd_region,\ndrivers/nvdimm/label.c-1069-\t\tstruct nd_namespace_pmem nspm, resource_size_t size)\n--\ndrivers/nvdimm/label.h=223=struct nd_namespace_pmem;\ndrivers/nvdimm/label.h:224:int nd_pmem_namespace_label_update(struct nd_region nd_region,\ndrivers/nvdimm/label.h-225-\t\tstruct nd_namespace_pmem nspm, resource_size_t size);\n--\ndrivers/nvdimm/namespace_devs.c=235=static int nd_namespace_label_update(struct nd_region nd_region,\n--\ndrivers/nvdimm/namespace_devs.c-255-\ndrivers/nvdimm/namespace_devs.c:256:\t\treturn nd_pmem_namespace_label_update(nd_region, nspm, size);\ndrivers/nvdimm/namespace_devs.c-257-\t} else\n--\ndrivers/nvdimm/namespace_devs.c=607=int __reserve_free_pmem(struct device dev, void data)\n--\ndrivers/nvdimm/namespace_devs.c-629-\ndrivers/nvdimm/namespace_devs.c:630:\t\tn = nd_pmem_available_dpa(nd_region, nd_mapping);\ndrivers/nvdimm/namespace_devs.c-631-\t\tif (n == 0)\n--\ndrivers/nvdimm/nd-core.h=85=bool is_nvdimm(const struct device dev);\ndrivers/nvdimm/nd-core.h:86:bool is_nd_pmem(const struct device dev);\ndrivers/nvdimm/nd-core.h-87-bool is_nd_volatile(const struct device dev);\ndrivers/nvdimm/nd-core.h=88=static inline bool is_nd_region(const struct device dev)\ndrivers/nvdimm/nd-core.h-89-{\ndrivers/nvdimm/nd-core.h:90:\treturn is_nd_pmem(dev) \|\| is_nd_volatile(dev);\ndrivers/nvdimm/nd-core.h-91-}\ndrivers/nvdimm/nd-core.h=92=static inline bool is_memory(const struct device dev)\ndrivers/nvdimm/nd-core.h-93-{\ndrivers/nvdimm/nd-core.h:94:\treturn is_nd_pmem(dev) \|\| is_nd_volatile(dev);\ndrivers/nvdimm/nd-core.h-95-}\n--\ndrivers/nvdimm/nd-core.h=121=void release_free_pmem(struct nvdimm_bus nvdimm_bus,\n--\ndrivers/nvdimm/nd-core.h-123-\ndrivers/nvdimm/nd-core.h:124:resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region nd_region,\ndrivers/nvdimm/nd-core.h-125-\t\t\t\t\t struct nd_mapping nd_mapping);\ndrivers/nvdimm/nd-core.h=126=resource_size_t nd_region_allocatable_dpa(struct nd_region nd_region);\ndrivers/nvdimm/nd-core.h:127:resource_size_t nd_pmem_available_dpa(struct nd_region nd_region,\ndrivers/nvdimm/nd-core.h-128-\t\t\t\t struct nd_mapping nd_mapping);\n--\ndrivers/nvdimm/pmem.c=463=static int pmem_attach_disk(struct device dev,\n--\ndrivers/nvdimm/pmem.c-610-\ndrivers/nvdimm/pmem.c:611:static int nd_pmem_probe(struct device dev)\ndrivers/nvdimm/pmem.c-612-{\n--\ndrivers/nvdimm/pmem.c-662-\ndrivers/nvdimm/pmem.c:663:static void nd_pmem_remove(struct device dev)\ndrivers/nvdimm/pmem.c-664-{\n--\ndrivers/nvdimm/pmem.c-671-\t\t * Note, this assumes device_lock() context to not\ndrivers/nvdimm/pmem.c:672:\t\t * race nd_pmem_notify()\ndrivers/nvdimm/pmem.c-673-\t\t /\n--\ndrivers/nvdimm/pmem.c-679-\ndrivers/nvdimm/pmem.c:680:static void nd_pmem_shutdown(struct device dev)\ndrivers/nvdimm/pmem.c-681-{\n--\ndrivers/nvdimm/pmem.c=732=static void pmem_revalidate_region(struct device dev)\n--\ndrivers/nvdimm/pmem.c-747-\ndrivers/nvdimm/pmem.c:748:static void nd_pmem_notify(struct device dev, enum nvdimm_event event)\ndrivers/nvdimm/pmem.c-749-{\n--\ndrivers/nvdimm/pmem.c=765=MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);\ndrivers/nvdimm/pmem.c:766:static struct nd_device_driver nd_pmem_driver = {\ndrivers/nvdimm/pmem.c:767:\t.probe = nd_pmem_probe,\ndrivers/nvdimm/pmem.c:768:\t.remove = nd_pmem_remove,\ndrivers/nvdimm/pmem.c:769:\t.notify = nd_pmem_notify,\ndrivers/nvdimm/pmem.c:770:\t.shutdown = nd_pmem_shutdown,\ndrivers/nvdimm/pmem.c-771-\t.drv = {\ndrivers/nvdimm/pmem.c:772:\t\t.name = \"nd_pmem\",\ndrivers/nvdimm/pmem.c-773-\t},\n--\ndrivers/nvdimm/pmem.c-776-\ndrivers/nvdimm/pmem.c:777:module_nd_driver(nd_pmem_driver);\ndrivers/nvdimm/pmem.c-778-\n--\ndrivers/nvdimm/region_devs.c=368=resource_size_t nd_region_available_dpa(struct nd_region nd_region)\n--\ndrivers/nvdimm/region_devs.c-383-\ndrivers/nvdimm/region_devs.c:384:\t\tavailable += nd_pmem_available_dpa(nd_region, nd_mapping);\ndrivers/nvdimm/region_devs.c-385-\t}\n--\ndrivers/nvdimm/region_devs.c=390=resource_size_t nd_region_allocatable_dpa(struct nd_region nd_region)\n--\ndrivers/nvdimm/region_devs.c-398-\ndrivers/nvdimm/region_devs.c:399:\t\tavail = min_not_zero(avail, nd_pmem_max_contiguous_dpa(\ndrivers/nvdimm/region_devs.c-400-\t\t\t\t\t\t nd_region, nd_mapping));\n--\ndrivers/nvdimm/region_devs.c=808=static const struct attribute_group nd_region_attribute_groups[] = {\n--\ndrivers/nvdimm/region_devs.c-815-\ndrivers/nvdimm/region_devs.c:816:static const struct device_type nd_pmem_device_type = {\ndrivers/nvdimm/region_devs.c:817:\t.name = \"nd_pmem\",\ndrivers/nvdimm/region_devs.c-818-\t.release = nd_region_release,\n--\ndrivers/nvdimm/region_devs.c=822=static const struct device_type nd_volatile_device_type = {\n--\ndrivers/nvdimm/region_devs.c-827-\ndrivers/nvdimm/region_devs.c:828:bool is_nd_pmem(const struct device dev)\ndrivers/nvdimm/region_devs.c-829-{\ndrivers/nvdimm/region_devs.c:830:\treturn dev ? dev-\u003etype == \u0026nd_pmem_device_type : false;\ndrivers/nvdimm/region_devs.c-831-}\n--\ndrivers/nvdimm/region_devs.c=1063=struct nd_region nvdimm_pmem_region_create(struct nvdimm_bus nvdimm_bus,\n--\ndrivers/nvdimm/region_devs.c-1066-\tndr_desc-\u003enum_lanes = ND_MAX_LANES;\ndrivers/nvdimm/region_devs.c:1067:\treturn nd_region_create(nvdimm_bus, ndr_desc, \u0026nd_pmem_device_type,\ndrivers/nvdimm/region_devs.c-1068-\t\t\t__func__);\n--\ndrivers/nvdimm/region_devs.c=1176=int nvdimm_has_cache(struct nd_region nd_region)\ndrivers/nvdimm/region_devs.c-1177-{\ndrivers/nvdimm/region_devs.c:1178:\treturn is_nd_pmem(\u0026nd_region-\u003edev) \u0026\u0026\ndrivers/nvdimm/region_devs.c-1179-\t\t!test_bit(ND_REGION_PERSIST_CACHE, \u0026nd_region-\u003eflags);\n--\ndrivers/nvdimm/region_devs.c=1183=bool is_nvdimm_sync(struct nd_region nd_region)\n--\ndrivers/nvdimm/region_devs.c-1187-\ndrivers/nvdimm/region_devs.c:1188:\treturn is_nd_pmem(\u0026nd_region-\u003edev) \u0026\u0026\ndrivers/nvdimm/region_devs.c-1189-\t\t!test_bit(ND_REGION_ASYNC, \u0026nd_region-\u003eflags);\n" }
13/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 11071 output: 37 thoughts: 56 Thoughts: Okay, let's dive into this. Here's how I'd approach understanding the code: Digging into `pmem_mkpage_present` in `drivers/nvdimm/pmem.c` Right, so I need to understand the call sites of `pmem_mkpage_present`. It's a key function in that driver, and I want a clear picture of its role. So, my first step is to locate all the invocations of that function within `drivers/nvdimm/pmem.c`. I expect it'll be fairly focused since it's likely dealing with a specific aspect of persistent memory management. Now, let's get into the specifics, I think it will be helpful to look at lines 50 to 120 of `drivers/nvdimm/pmem.c`. I have a feeling that this will provide important context around how `pmem_mkpage_present` fits into the broader picture of the driver's operation. I'm hoping I'll see some clear patterns or specific data structures that are related to persistent memory allocation or page management within the NVDIMM framework. I'm keeping an open mind for now, but I'm expecting this section to provide some critical insight into the design decisions around handling persistent memory in this specific context.
14/2	2026/09/25 11:21	tool	read-file	0m Args: { "File": "drivers/nvdimm/pmem.c", "FirstLine": 55, "LineCount": 60 } Results: { "Contents": " 55:\t\treturn (offset - pmem-\u003edata_offset) \u003e\u003e SECTOR_SHIFT;\n 56:\t}\n 57:\t\n 58:\tstatic phys_addr_t to_offset(struct pmem_device pmem, sector_t sector)\n 59:\t{\n 60:\t\treturn (sector \u003c\u003c SECTOR_SHIFT) + pmem-\u003edata_offset;\n 61:\t}\n 62:\t\n 63:\tstatic void pmem_mkpage_present(struct pmem_device pmem, phys_addr_t offset,\n 64:\t\t\tunsigned int len)\n 65:\t{\n 66:\t\tphys_addr_t phys = pmem_to_phys(pmem, offset);\n 67:\t\tunsigned long pfn_start, pfn_end, pfn;\n 68:\t\n 69:\t\t/* only pmem in the linear map supports HWPoison /\n 70:\t\tif (is_vmalloc_addr(pmem-\u003evirt_addr))\n 71:\t\t\treturn;\n 72:\t\n 73:\t\tpfn_start = PHYS_PFN(phys);\n 74:\t\tpfn_end = pfn_start + PHYS_PFN(len);\n 75:\t\tfor (pfn = pfn_start; pfn \u003c pfn_end; pfn++) {\n 76:\t\t\tstruct page page = pfn_to_page(pfn);\n 77:\t\n 78:\t\t\t/\n 79:\t\t\t Note, no need to hold a get_dev_pagemap() reference\n 80:\t\t\t * here since we're in the driver I/O path and\n 81:\t\t\t * outstanding I/O requests pin the dev_pagemap.\n 82:\t\t\t /\n 83:\t\t\tif (TestClearPageHWPoison(page))\n 84:\t\t\t\tclear_mce_nospec(pfn);\n 85:\t\t}\n 86:\t}\n 87:\t\n 88:\tstatic void pmem_clear_bb(struct pmem_device pmem, sector_t sector, long blks)\n 89:\t{\n 90:\t\tif (blks == 0)\n 91:\t\t\treturn;\n 92:\t\tbadblocks_clear(\u0026pmem-\u003ebb, sector, blks);\n 93:\t\tif (pmem-\u003ebb_state)\n 94:\t\t\tsysfs_notify_dirent(pmem-\u003ebb_state);\n 95:\t}\n 96:\t\n 97:\tstatic long __pmem_clear_poison(struct pmem_device pmem,\n 98:\t\t\tphys_addr_t offset, unsigned int len)\n 99:\t{\n 100:\t\tphys_addr_t phys = pmem_to_phys(pmem, offset);\n 101:\t\tlong cleared = nvdimm_clear_poison(to_dev(pmem), phys, len);\n 102:\t\n 103:\t\tif (cleared \u003e 0) {\n 104:\t\t\tpmem_mkpage_present(pmem, offset, cleared);\n 105:\t\t\tarch_invalidate_pmem(pmem-\u003evirt_addr + offset, len);\n 106:\t\t}\n 107:\t\treturn cleared;\n 108:\t}\n 109:\t\n 110:\tstatic blk_status_t pmem_clear_poison(struct pmem_device pmem,\n 111:\t\t\tphys_addr_t offset, unsigned int len)\n 112:\t{\n 113:\t\tlong cleared = __pmem_clear_poison(pmem, offset, len);\n 114:\t\n" }
15/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 12379 output: 31 thoughts: 54 Thoughts: Okay, let's break this down. Investigating the `pmem_clear_poison` Function Right, so I'm trying to understand the circumstances that trigger `pmem_clear_poison`. From what I'm seeing here, it's connected to clearing "badblocks" or "poison" during write operations. Specifically, this happens during the write requests themselves, that is, inside `pmem_do_write` or at the point of bio submission. My next logical step is to pinpoint where exactly this crucial `pmem_clear_poison` function is being called. That's where I need to dig in a bit further to see the larger context.
16/2	2026/09/25 11:21	tool	grepper	0m Args: { "Expression": "pmem_clear_poison", "PathPrefix": "drivers/nvdimm" } Results: { "Output": "drivers/nvdimm/pmem.c=88=static void pmem_clear_bb(struct pmem_device pmem, sector_t sector, long blks)\n--\ndrivers/nvdimm/pmem.c-96-\ndrivers/nvdimm/pmem.c:97:static long __pmem_clear_poison(struct pmem_device pmem,\ndrivers/nvdimm/pmem.c-98-\t\tphys_addr_t offset, unsigned int len)\n--\ndrivers/nvdimm/pmem.c-109-\ndrivers/nvdimm/pmem.c:110:static blk_status_t pmem_clear_poison(struct pmem_device pmem,\ndrivers/nvdimm/pmem.c-111-\t\tphys_addr_t offset, unsigned int len)\ndrivers/nvdimm/pmem.c-112-{\ndrivers/nvdimm/pmem.c:113:\tlong cleared = __pmem_clear_poison(pmem, offset, len);\ndrivers/nvdimm/pmem.c-114-\n--\ndrivers/nvdimm/pmem.c=180=static blk_status_t pmem_do_write(struct pmem_device pmem,\n--\ndrivers/nvdimm/pmem.c-187-\tif (unlikely(is_bad_pmem(\u0026pmem-\u003ebb, sector, len))) {\ndrivers/nvdimm/pmem.c:188:\t\tblk_status_t rc = pmem_clear_poison(pmem, pmem_off, len);\ndrivers/nvdimm/pmem.c-189-\n--\ndrivers/nvdimm/pmem.c=340=static size_t pmem_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff,\n--\ndrivers/nvdimm/pmem.c-364-\tpmem_off = PFN_PHYS(pgoff) + pmem-\u003edata_offset;\ndrivers/nvdimm/pmem.c:365:\tcleared = __pmem_clear_poison(pmem, pmem_off, len);\ndrivers/nvdimm/pmem.c-366-\tif (cleared \u003e 0 \u0026\u0026 cleared \u003c len) {\n" }
17/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 13193 output: 31 thoughts: 37 Thoughts: Okay, let's break this down. Diving into the pmem Write Path Alright, so I'm focusing on the pmem block device write path. The initial clue is `pmem_do_write`, which I suspect is the entry point. Now, to understand how writes are actually handled, I need to trace the execution flow from there. My next move is clear: I'm going straight to investigate `pmem_submit_bio`. It's almost guaranteed to be the next significant function involved in the process, likely handling the submission of a bio (Block IO) to the underlying pmem device. This is where the real work of initiating the write operation will likely be done. Let's see what we've got.
18/2	2026/09/25 11:21	tool	grepper	0m Args: { "Expression": "pmem_do_write", "PathPrefix": "drivers/nvdimm" } Results: { "Output": "drivers/nvdimm/pmem.c=164=static blk_status_t pmem_do_read(struct pmem_device pmem,\n--\ndrivers/nvdimm/pmem.c-179-\ndrivers/nvdimm/pmem.c:180:static blk_status_t pmem_do_write(struct pmem_device pmem,\ndrivers/nvdimm/pmem.c-181-\t\t\tstruct page page, unsigned int page_off,\n--\ndrivers/nvdimm/pmem.c=200=static void pmem_submit_bio(struct bio bio)\n--\ndrivers/nvdimm/pmem.c-225-\t\t\tif (op_is_write(bio_op(bio)))\ndrivers/nvdimm/pmem.c:226:\t\t\t\trc = pmem_do_write(pmem, bvec.bv_page,\ndrivers/nvdimm/pmem.c-227-\t\t\t\t\t\t bvec.bv_offset,\n--\ndrivers/nvdimm/pmem.c=308=static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,\n--\ndrivers/nvdimm/pmem.c-312-\ndrivers/nvdimm/pmem.c:313:\treturn blk_status_to_errno(pmem_do_write(pmem, ZERO_PAGE(0), 0,\ndrivers/nvdimm/pmem.c-314-\t\t\t\t PFN_PHYS(pgoff) \u003e\u003e SECTOR_SHIFT,\n" }
19/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 13831 output: 20 thoughts: 37 Thoughts: Okay, here's my take on those thoughts, tailored for an expert audience: Analyzing the Code Change Right, let's dive into this patch. Before I even think about merging it or suggesting modifications, my first step is always a thorough examination. I need to understand precisely what this commit is modifying. I'm going to start by pulling up the `git log` output for that specific commit, or the commit message if it's well-written. The goal here isn't just to see the surface-level changes, but to get a clear picture of the reasoning behind them. What problem was the developer trying to solve? What was the context? Understanding the 'why' is just as crucial as understanding the 'what'. This is where I begin the analysis process.
20/2	2026/09/25 11:21	tool	grepper	0m Args: { "Expression": "TestClearPageHWPoison" } Results: { "Output": "drivers/nvdimm/pmem.c=63=static void pmem_mkpage_present(struct pmem_device pmem, phys_addr_t offset,\n--\ndrivers/nvdimm/pmem.c-82-\t\t /\ndrivers/nvdimm/pmem.c:83:\t\tif (TestClearPageHWPoison(page))\ndrivers/nvdimm/pmem.c-84-\t\t\tclear_mce_nospec(pfn);\n--\nmm/memory-failure.c=2736=int unpoison_memory(unsigned long pfn)\n--\nmm/memory-failure.c-2822-\t\tfolio_put(folio);\nmm/memory-failure.c:2823:\t\tif (TestClearPageHWPoison(p)) {\nmm/memory-failure.c-2824-\t\t\tfolio_put(folio);\n--\nmm/page_alloc.c=7854=bool put_page_back_buddy(struct page *page)\n--\nmm/page_alloc.c-7864-\t\t__free_one_page(page, pfn, zone, 0, migratetype, FPI_NONE);\nmm/page_alloc.c:7865:\t\tif (TestClearPageHWPoison(page))\nmm/page_alloc.c-7866-\t\t\treturn true;\n" }
21/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 14398 output: 36 thoughts: 133 Thoughts: Okay, let's see... I need to get a handle on this. My initial instinct is to dive into a few key files: `mm/page_alloc.c`, `mm/memory-failure.c`, and `drivers/nvdimm/pmem.c`. Those seem like the logical places to start given what I'm trying to grok. Deconstructing the Memory Allocation and Failure Mechanism Hold on... I'm noticing something crucial in `mm/page_alloc.c`: `if (TestClearPageHWPoison(page))`. This immediately piques my interest. It implies some hardware-level checking or marking is going on. Now, a follow-up question. Hang on... This is important: let me get this straight, inside of `mm/page_alloc.c`, is that file compiled with or without `CONFIG_MEMORY_FAILURE`? That conditional compilation is the key. Is this feature enabled or disabled? I need to know how these failure mechanisms are actually integrated into the core allocation path. Okay, let's check it: I need to verify whether `mm/page_alloc.c` has `#ifdef CONFIG_MEMORY_FAILURE` blocks around `put_page_back_buddy`. That'll confirm whether the memory failure handling is conditionally compiled within the buddy allocator's return path. Gotta see how tightly integrated these failure paths are with the normal allocation path.
22/2	2026/09/25 11:21	tool	read-file	0m Args: { "File": "mm/page_alloc.c", "FirstLine": 7850, "LineCount": 25 } Results: { "Contents": "7850:\t\n7851:\t/\n7852:\t Cancel takeoff done by take_page_off_buddy().\n7853:\t /\n7854:\tbool put_page_back_buddy(struct page page)\n7855:\t{\n7856:\t\tstruct zone *zone = page_zone(page);\n7857:\t\n7858:\t\tguard(spinlock_irqsave)(\u0026zone-\u003elock);\n7859:\t\tif (put_page_testzero(page)) {\n7860:\t\t\tunsigned long pfn = page_to_pfn(page);\n7861:\t\t\tint migratetype = get_pfnblock_migratetype(page, pfn);\n7862:\t\n7863:\t\t\tClearPageHWPoisonTakenOff(page);\n7864:\t\t\t__free_one_page(page, pfn, zone, 0, migratetype, FPI_NONE);\n7865:\t\t\tif (TestClearPageHWPoison(page))\n7866:\t\t\t\treturn true;\n7867:\t\t}\n7868:\t\n7869:\t\treturn false;\n7870:\t}\n7871:\t#endif\n7872:\t\n7873:\tbool has_managed_zone(enum zone_type zone)\n7874:\t{\n" }
23/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 15225 output: 36 thoughts: 27 Thoughts: Here's my thought process, summarized as you requested: Navigating a Code Block Okay, so I'm at line 7871 and I see a `#endif`. This immediately triggers me to look for the corresponding conditional compilation block. Since I see the `#endif`, I know there should be a `#if`, `#ifdef`, or something similar higher up. I want to see what that condition is. I figure that to understand the scope and intent of this `#endif`, I need to see what's being conditionally compiled. I'm going to start by quickly glancing back at line 7850 and then just scanning upwards to find the beginning of the block that this `#endif` is closing out. I'm hoping to quickly identify the `#if` statement or the relevant preprocessor directive to understand what's being conditionally included or excluded.
24/2	2026/09/25 11:21	tool	read-file	0m Args: { "File": "mm/page_alloc.c", "FirstLine": 7840, "LineCount": 15 } Results: { "Contents": "7840:\t\t\t\tbreak_down_buddy_pages(zone, page_head, page, 0,\n7841:\t\t\t\t\t\t\tpage_order, migratetype);\n7842:\t\t\t\tSetPageHWPoisonTakenOff(page);\n7843:\t\t\t\treturn true;\n7844:\t\t\t}\n7845:\t\t\tif (page_count(page_head) \u003e 0)\n7846:\t\t\t\tbreak;\n7847:\t\t}\n7848:\t\treturn false;\n7849:\t}\n7850:\t\n7851:\t/\n7852:\t Cancel takeoff done by take_page_off_buddy().\n7853:\t /\n7854:\tbool put_page_back_buddy(struct page page)\n" }
25/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 15680 output: 33 thoughts: 1881 Thoughts: Analyzing a NVDIMM Patch for Fuzzing Suitability Okay, so I'm looking at this patch and immediately, my brain zeroes in on those preprocessor directives `#ifdef CONFIG_MEMORY_FAILURE`. That's always a red flag, meaning that parts of the code are conditionally compiled, and I need to understand the impact of the configuration. The patch modifies `take_page_off_buddy` and `put_page_back_buddy` via those directives. But more importantly, there's `TESTSCFLAG_FALSE(HWPoison, hwpoison)` being added in `include/linux/page-flags.h`. It seems the reason for this is to ensure `TestClearPageHWPoison(page)` exists even when `CONFIG_MEMORY_FAILURE` isn't defined. Without it, the compiler would choke because `pmem.h` was defining its own wrapper `test_and_clear_pmem_poison()`. This patch then removes this custom wrapper, replacing it with the standard function. My initial thought is "no functional change," but I can't be complacent. I have to verify if this is reachable code that needs to be fuzzed. The triage instructions are very clear: don't trust claims of no functional change without careful analysis, as even refactorings can introduce subtle bugs. The change in `drivers/nvdimm/pmem.c` is a straightforward replacement: `test_and_clear_pmem_poison(page)` becomes `TestClearPageHWPoison(page)`. When `CONFIG_MEMORY_FAILURE` is active, the behavior is identical; with `CONFIG_MEMORY_FAILURE` inactive, the custom wrapper returns false, and now, the replaced function also returns 0, which is functionally the same result. So, the generated assembly should be identical. However, I've seen enough to know to not blindly trust that statement. The triage instructions are very clear. Section 2, the "negative criteria," states that if all modified code falls into certain categories, then fuzzing is not needed. But if it touches reachable executable code, fuzzing is needed. I need to meticulously re-examine the negative criteria to see if this patch is exempt. - Is it a non-kernel or non-executable change? No, it touches `include/linux/page-flags.h` and `drivers/nvdimm/pmem.c`, which are critical parts of the kernel. - Is it structurally unreachable hardware? I need to determine if NVDIMM and pmem are reachable. I know that NVDIMM can be emulated in QEMU (using `qemu-system-x86_64 -machine pc,nvdimm=on`, ACPI NFIT, virtio-pmem, or `memmap=`). - Is it structurally unreachable code path? It doesn't appear to be driver teardown/hot-unplug or architecture-specific, so that's not the issue. Given that NVDIMM/pmem is emulated in QEMU, this code path is reachable. Does syzkaller test NVDIMM? While I don't have access to the syzkaller specification tools in this context, the presence of NVDIMM emulation in QEMU heavily suggests that this code can be reached during testing. I can probe to see if `nd_pmem` or `pmem` is loadable or usable. And I'll double check `CONFIG_BLK_DEV_PMEM`. Therefore, the patch does modify reachable executable code. Therefore, based on the triage instructions, this patch needs to be fuzzed.
26/2	2026/09/25 11:21	tool	grepper	0m Args: { "Expression": "config BLK_DEV_PMEM", "PathPrefix": "drivers/nvdimm" } Results: { "Output": "drivers/nvdimm/Kconfig=17=if LIBNVDIMM\ndrivers/nvdimm/Kconfig-18-\ndrivers/nvdimm/Kconfig:19:config BLK_DEV_PMEM\ndrivers/nvdimm/Kconfig-20-\ttristate \"PMEM: Persistent memory block device support\"\n" }
27/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 18471 output: 34 thoughts: 20 Thoughts: Here's a summary of my thought process, as requested: Navigating the NVDIMM Kconfig Configuration Okay, so I'm diving into the `drivers/nvdimm/Kconfig` file. I'm focusing specifically around line 17. That's usually where the core configuration options for a driver begin, or at least the section for the overall NVDIMM subsystem. I'm guessing that this will be where the fundamental `CONFIG_NVDIMM` option is defined, along with maybe some of the basic prerequisites or dependencies. This is where I can get a sense of the scope of the configuration options. I need to understand this to determine the appropriate options.
28/2	2026/09/25 11:21	tool	read-file	0m Args: { "File": "drivers/nvdimm/Kconfig", "FirstLine": 1, "LineCount": 50 } Results: { "Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0-only\n 2:\tmenuconfig LIBNVDIMM\n 3:\t\ttristate \"NVDIMM (Non-Volatile Memory Device) Support\"\n 4:\t\tdepends on PHYS_ADDR_T_64BIT\n 5:\t\tdepends on HAS_IOMEM\n 6:\t\tdepends on BLK_DEV\n 7:\t\tselect MEMREGION\n 8:\t\thelp\n 9:\t\t Generic support for non-volatile memory devices including\n 10:\t\t ACPI-6-NFIT defined resources. On platforms that define an\n 11:\t\t NFIT, or otherwise can discover NVDIMM resources, a libnvdimm\n 12:\t\t bus is registered to advertise PMEM (persistent memory)\n 13:\t\t namespaces (/dev/pmemX). A PMEM namespace refers to a\n 14:\t\t memory resource that may span multiple DIMMs and support DAX\n 15:\t\t (see CONFIG_DAX).\n 16:\t\n 17:\tif LIBNVDIMM\n 18:\t\n 19:\tconfig BLK_DEV_PMEM\n 20:\t\ttristate \"PMEM: Persistent memory block device support\"\n 21:\t\tdefault LIBNVDIMM\n 22:\t\tselect DAX\n 23:\t\tselect ND_BTT if BTT\n 24:\t\tselect ND_PFN if NVDIMM_PFN\n 25:\t\thelp\n 26:\t\t Memory ranges for PMEM are described by either an NFIT\n 27:\t\t (NVDIMM Firmware Interface Table, see CONFIG_ACPI_NFIT), a\n 28:\t\t non-standard OEM-specific E820 memory type (type-12, see\n 29:\t\t CONFIG_X86_PMEM_LEGACY), or it is manually specified by the\n 30:\t\t 'memmap=nn[KMG]!ss[KMG]' kernel command line (see\n 31:\t\t Documentation/admin-guide/kernel-parameters.rst). This driver converts\n 32:\t\t these persistent memory ranges into block devices that are\n 33:\t\t capable of DAX (direct-access) file system mappings. See\n 34:\t\t Documentation/driver-api/nvdimm/nvdimm.rst for more details.\n 35:\t\n 36:\t\t Say Y if you want to use an NVDIMM\n 37:\t\n 38:\tconfig ND_CLAIM\n 39:\t\tbool\n 40:\t\n 41:\tconfig ND_BTT\n 42:\t\ttristate\n 43:\t\n 44:\tconfig BTT\n 45:\t\tbool \"BTT: Block Translation Table (atomic sector updates)\"\n 46:\t\tdefault y if LIBNVDIMM\n 47:\t\tselect ND_CLAIM\n 48:\t\thelp\n 49:\t\t The Block Translation Table (BTT) provides atomic sector\n 50:\t\t update semantics for persistent memory devices, so that\n" }
29/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 19420 output: 31 thoughts: 1985 Thoughts: Fuzzing Decision for the PMEM Poison Cleanup Patch Okay, let's break this down. First, I see this patch is about cleaning up how hardware poisoning flags are handled in the Persistent Memory (PMEM) driver. It's essentially refactoring by exposing `TestClearPageHWPoison` and removing a custom wrapper function. The files touched are core: `include/linux/page-flags.h`, `drivers/nvdimm/pmem.c`, and a header in the same directory. This touches core memory management and driver code; there's some change in logic within this area, specifically around how the hardware poisoning is tested/cleared. My initial thought is to see if this is worth fuzzing, and I need to be really careful and apply the criteria precisely. Let's see if this falls into any of the negative criteria. It's not documentation or comments. It's not unreachable hardware like a niche PCIe switch – the PMEM driver is definitely within the realm of potential emulation, even if it might need a specific configuration. The most critical question here is reachability. Can `pmem_mkpage_present` be executed in standard fuzzing environments? Does syzkaller, QEMU, or any other standard setup support PMEM or NVDIMM devices? Do they even have `CONFIG_BLK_DEV_PMEM` enabled? It's not a vendor-specific piece of hardware that's impossible to emulate. These are more accessible through standard memory interfaces, right? The key here is not whether I have a PMEM device on my machine, but whether standard fuzzing setups do. Reading the instructions closely, this definitely sounds like the "Refactorings and Code Cleanups" positive criteria: "Any restructuring of reachable data structures, helper abstractions, or algorithm flows." It touches core mm header, refactors a driver function to use a standard call. This isn't a simple cosmetic change. It touches reachable code in a driver that, potentially, can be accessed. I can't definitively say "no," this is unreachable. I need to establish whether a standard QEMU / Syzkaller environment could trigger code affected by this patch. Thus, this is worth fuzzing.
30/2	2026/09/25 11:21	tool	grepper	0m Args: { "Expression": "nd_pmem_driver", "PathPrefix": "drivers/nvdimm" } Results: { "Output": "drivers/nvdimm/pmem.c=765=MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);\ndrivers/nvdimm/pmem.c:766:static struct nd_device_driver nd_pmem_driver = {\ndrivers/nvdimm/pmem.c-767-\t.probe = nd_pmem_probe,\n--\ndrivers/nvdimm/pmem.c-776-\ndrivers/nvdimm/pmem.c:777:module_nd_driver(nd_pmem_driver);\ndrivers/nvdimm/pmem.c-778-\n" }
31/2	2026/09/25 11:21	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 22084 output: 29 thoughts: 27 Thoughts: Okay, let's dive into this. Here's how I'd approach summarizing those thoughts, focusing on the core ideas: Namespace Exploration - A Quick Detour Alright, I'm thinking about namespaces and how they're handled. Specifically, I need to refresh my memory on how the system probes for and creates them. Got to get the details correct to inform whatever design I'm working on. Wait a second, though... I'm getting a nagging feeling that I'm forgetting something crucial. Did I miss something related to `nd_e820.c`? Gotta make sure I'm not overlooking a critical piece of information related to that file as it may affect how this works overall.
32/2	2026/09/25 11:22	tool	grepper	0m Args: { "Expression": "e820", "PathPrefix": "drivers/nvdimm" } Results: { "Output": "drivers/nvdimm/Kconfig=100=config RAMDAX\n--\ndrivers/nvdimm/Kconfig-113-\t (see 'ndctl create-namespace --help').\ndrivers/nvdimm/Kconfig:114:\t The driver should be force bound to e820_pmem or pmem-region platform\ndrivers/nvdimm/Kconfig-115-\t devices using 'driver_override' device attribute.\n--\ndrivers/nvdimm/Makefile=4=obj-$(CONFIG_ND_BTT) += nd_btt.o\ndrivers/nvdimm/Makefile:5:obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o\ndrivers/nvdimm/Makefile-6-obj-$(CONFIG_OF_PMEM) += of_pmem.o\n--\ndrivers/nvdimm/Makefile=12=nd_btt-y := btt.o\ndrivers/nvdimm/Makefile-13-\ndrivers/nvdimm/Makefile:14:nd_e820-y := e820.o\ndrivers/nvdimm/Makefile-15-\n--\ndrivers/nvdimm/e820.c-11-\ndrivers/nvdimm/e820.c:12:static void e820_pmem_remove(struct platform_device pdev)\ndrivers/nvdimm/e820.c-13-{\n--\ndrivers/nvdimm/e820.c-18-\ndrivers/nvdimm/e820.c:19:static int e820_register_one(struct resource res, void data)\ndrivers/nvdimm/e820.c-20-{\n--\ndrivers/nvdimm/e820.c-34-\ndrivers/nvdimm/e820.c:35:static int e820_pmem_probe(struct platform_device pdev)\ndrivers/nvdimm/e820.c-36-{\n--\ndrivers/nvdimm/e820.c-41-\ndrivers/nvdimm/e820.c:42:\tnd_desc.provider_name = \"e820\";\ndrivers/nvdimm/e820.c-43-\tnd_desc.module = THIS_MODULE;\n--\ndrivers/nvdimm/e820.c-49-\trc = walk_iomem_res_desc(IORES_DESC_PERSISTENT_MEMORY_LEGACY,\ndrivers/nvdimm/e820.c:50:\t\t\tIORESOURCE_MEM, 0, -1, nvdimm_bus, e820_register_one);\ndrivers/nvdimm/e820.c-51-\tif (rc)\n--\ndrivers/nvdimm/e820.c-59-\ndrivers/nvdimm/e820.c:60:static struct platform_driver e820_pmem_driver = {\ndrivers/nvdimm/e820.c:61:\t.probe = e820_pmem_probe,\ndrivers/nvdimm/e820.c:62:\t.remove = e820_pmem_remove,\ndrivers/nvdimm/e820.c-63-\t.driver = {\ndrivers/nvdimm/e820.c:64:\t\t.name = \"e820_pmem\",\ndrivers/nvdimm/e820.c-65-\t},\n--\ndrivers/nvdimm/e820.c-67-\ndrivers/nvdimm/e820.c:68:module_platform_driver(e820_pmem_driver);\ndrivers/nvdimm/e820.c-69-\ndrivers/nvdimm/e820.c:70:MODULE_ALIAS(\"platform:e820_pmem\");\ndrivers/nvdimm/e820.c:71:MODULE_DESCRIPTION(\"NVDIMM support for e820 type-12 memory\");\ndrivers/nvdimm/e820.c-72-MODULE_LICENSE(\"GPL v2\");\n--\ndrivers/nvdimm/ramdax.c-4- \ndrivers/nvdimm/ramdax.c:5: * Based on e820 pmem driver:\ndrivers/nvdimm/ramdax.c-6- * Copyright (c) 2015, Christoph Hellwig.\n--\ndrivers/nvdimm/ramdax.c=278=module_platform_driver(ramdax_driver);\ndrivers/nvdimm/ramdax.c-279-\ndrivers/nvdimm/ramdax.c:280:MODULE_DESCRIPTION(\"NVDIMM support for e820 type-12 memory and OF pmem-region\");\ndrivers/nvdimm/ramdax.c-281-MODULE_LICENSE(\"GPL\");\n" }
33/2	2026/09/25 11:22	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 23529 output: 18 thoughts: 570 Thoughts: My Line of Inquiry: PMEM Poison Clearing and Fuzzing Relevance Okay, first things first, my mind immediately jumps to a few key areas I need to investigate further. What about `nfit_test`, `nd_btt`, or `pmem`? These are all potentially relevant drivers or tools in the PMEM ecosystem. The bigger question is: can we even reach `pmem_mkpage_present`? That's the critical piece here. Let's trace the execution path. During PMEM I/O, specifically when writing to a block device, it looks like this: `pmem_submit_bio` triggers `pmem_do_write`. If there are any bad blocks, `pmem_clear_poison` kicks in, which calls `__pmem_clear_poison`, eventually leading to the `pmem_mkpage_present` function. The same path is taken in `pmem_recovery_write`, when there's DAX recovery. Now, let's examine `pmem_mkpage_present` itself. The function's critical. It takes a `pmem_device`, an offset, and a length. The interesting part is that it clears the hardware poison on pages within the PMEM region, but only if the PMEM is in the linear map. It uses `TestClearPageHWPoison` and `clear_mce_nospec`. But can syzkaller actually trigger this code path? That's the crux of the matter. So, my next thought is, can this code be reached during fuzzing? The next question is, does the standard QEMU fuzzing VM even include PMEM block devices by default? Even if it doesn't, is it possible to configure one, or even emulate PMEM, or create a PMEM device using ACPI, QEMU configuration, `nfit_test`, or even a device using dev_dax? That's what I need to check. To start, let me immediately delve into `nfit_test` in the `tools/testing/nvdimm/` directory. That seems like the most obvious starting point.
34/2	2026/09/25 11:22	tool	grepper	0m Args: { "Expression": "nfit_test" } Results: { "Output": "\nFull output is too long, showing 500 out of 1059 lines.\nUse more precise expression if possible.\n\nDocumentation/driver-api/nvdimm/nvdimm.rst=178=a dynamically assigned id.\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst-191- This bus is provided by the kernel under the device\nDocumentation/driver-api/nvdimm/nvdimm.rst:192: /sys/devices/platform/nfit_test.0 when the nfit_test.ko module from\nDocumentation/driver-api/nvdimm/nvdimm.rst-193- tools/testing/nvdimm is loaded. This module is a unit test for\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst=250=LIBNVDIMM: bus\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst-259-\nDocumentation/driver-api/nvdimm/nvdimm.rst:260:\t/sys/devices/platform/nfit_test.0/ndbus0\nDocumentation/driver-api/nvdimm/nvdimm.rst-261-\t\|-- commands\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst=282=Find the bus handle that describes the bus from Example NVDIMM Platform::\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst-295-\nDocumentation/driver-api/nvdimm/nvdimm.rst:296:\tbus = get_bus_by_provider(ctx, \"nfit_test.0\");\nDocumentation/driver-api/nvdimm/nvdimm.rst-297-\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst=312=LIBNVDIMM: DIMM (NMEM)\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst-322-\nDocumentation/driver-api/nvdimm/nvdimm.rst:323:\t/sys/devices/platform/nfit_test.0/ndbus0\nDocumentation/driver-api/nvdimm/nvdimm.rst-324-\t\|-- nmem0\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst=383=A generic REGION device is registered for each PMEM interleave-set /\nDocumentation/driver-api/nvdimm/nvdimm.rst:384:range. Per the example there are 2 PMEM regions on the \"nfit_test.0\"\nDocumentation/driver-api/nvdimm/nvdimm.rst-385-bus. The primary role of regions are to be a container of \"mappings\". A\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst=400=LIBNVDIMM: region::\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst-406-\nDocumentation/driver-api/nvdimm/nvdimm.rst:407:\t/sys/devices/platform/nfit_test.0/ndbus0\nDocumentation/driver-api/nvdimm/nvdimm.rst-408-\t\|-- region0\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst=468=attribute due to not support a LABEL)\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst-471-\nDocumentation/driver-api/nvdimm/nvdimm.rst:472:\t/sys/devices/platform/nfit_test.0/ndbus0/region0/namespace0.0\nDocumentation/driver-api/nvdimm/nvdimm.rst-473-\t\|-- alt_name\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst-484-\t`-- uuid\nDocumentation/driver-api/nvdimm/nvdimm.rst:485:\t/sys/devices/platform/nfit_test.1/ndbus1/region1/namespace1.0\nDocumentation/driver-api/nvdimm/nvdimm.rst-486-\t\|-- block\n--\nDocumentation/driver-api/nvdimm/nvdimm.rst=577=nd_blk driver depending on the region type::\nDocumentation/driver-api/nvdimm/nvdimm.rst-578-\nDocumentation/driver-api/nvdimm/nvdimm.rst:579:\t/sys/devices/platform/nfit_test.1/ndbus0/region0/btt0/\nDocumentation/driver-api/nvdimm/nvdimm.rst-580-\t\|-- namespace\n--\ndrivers/acpi/nfit/core.c=2131=static void acpi_nfit_init_dsms(struct acpi_nfit_desc acpi_desc)\n--\ndrivers/acpi/nfit/core.c-2141-\ndrivers/acpi/nfit/core.c:2142:\t/ enable nfit_test to inject bus command emulation /\ndrivers/acpi/nfit/core.c-2143-\tif (acpi_desc-\u003ebus_cmd_force_en) {\n--\ntools/testing/nvdimm/Kbuild=40=nfit-$(CONFIG_X86_MCE) += $(ACPI_SRC)/mce.o\ntools/testing/nvdimm/Kbuild:41:nfit-y += acpi_nfit_test.o\ntools/testing/nvdimm/Kbuild-42-nfit-y += config_check.o\n--\ntools/testing/nvdimm/acpi_nfit_test.c-8-\ntools/testing/nvdimm/acpi_nfit_test.c:9:nfit_test_watermark(acpi_nfit);\ntools/testing/nvdimm/acpi_nfit_test.c-10-\n--\ntools/testing/nvdimm/config_check.c=4=void check(void)\n--\ntools/testing/nvdimm/config_check.c-6-\t/\ntools/testing/nvdimm/config_check.c:7:\t * These kconfig symbols must be set to \"m\" for nfit_test to\ntools/testing/nvdimm/config_check.c-8-\t * load and operate.\n--\ntools/testing/nvdimm/dax-dev.c-4- /\ntools/testing/nvdimm/dax-dev.c:5:#include \"test/nfit_test.h\"\ntools/testing/nvdimm/dax-dev.c-6-#include \u003clinux/mm.h\u003e\n--\ntools/testing/nvdimm/dax_pmem_test.c-7-\ntools/testing/nvdimm/dax_pmem_test.c:8:nfit_test_watermark(dax_pmem);\n--\ntools/testing/nvdimm/device_dax_test.c-7-\ntools/testing/nvdimm/device_dax_test.c:8:nfit_test_watermark(device_dax);\n--\ntools/testing/nvdimm/libnvdimm_test.c-7-\ntools/testing/nvdimm/libnvdimm_test.c:8:nfit_test_watermark(libnvdimm);\n--\ntools/testing/nvdimm/pmem-dax.c-4- /\ntools/testing/nvdimm/pmem-dax.c:5:#include \"test/nfit_test.h\"\ntools/testing/nvdimm/pmem-dax.c-6-#include \u003clinux/blkdev.h\u003e\n--\ntools/testing/nvdimm/pmem-dax.c=11=long __pmem_direct_access(struct pmem_device pmem, pgoff_t pgoff,\n--\ntools/testing/nvdimm/pmem-dax.c-22-\t Limit dax to a single page at a time given vmalloc()-backed\ntools/testing/nvdimm/pmem-dax.c:23:\t * in the nfit_test case.\ntools/testing/nvdimm/pmem-dax.c-24-\t /\n--\ntools/testing/nvdimm/pmem_test.c-7-\ntools/testing/nvdimm/pmem_test.c:8:nfit_test_watermark(pmem);\n--\ntools/testing/nvdimm/test/Kbuild=3=ccflags-y += -I$(srctree)/drivers/acpi/nfit/\ntools/testing/nvdimm/test/Kbuild-4-\ntools/testing/nvdimm/test/Kbuild:5:obj-m += nfit_test.o\ntools/testing/nvdimm/test/Kbuild:6:obj-m += nfit_test_iomap.o\ntools/testing/nvdimm/test/Kbuild-7-\ntools/testing/nvdimm/test/Kbuild=8=ifeq ($(CONFIG_ACPI_NFIT),m)\ntools/testing/nvdimm/test/Kbuild:9:\tnfit_test-y := nfit.o\ntools/testing/nvdimm/test/Kbuild-10-\tobj-m += ndtest.o\ntools/testing/nvdimm/test/Kbuild=11=else\ntools/testing/nvdimm/test/Kbuild:12:\tnfit_test-y := ndtest.o\ntools/testing/nvdimm/test/Kbuild-13-endif\ntools/testing/nvdimm/test/Kbuild:14:nfit_test_iomap-y := iomap.o\n--\ntools/testing/nvdimm/test/iomap.c-13-#include \u003clinux/mm.h\u003e\ntools/testing/nvdimm/test/iomap.c:14:#include \"nfit_test.h\"\ntools/testing/nvdimm/test/iomap.c-15-\n--\ntools/testing/nvdimm/test/iomap.c=18=static struct iomap_ops {\ntools/testing/nvdimm/test/iomap.c:19:\tnfit_test_lookup_fn nfit_test_lookup;\ntools/testing/nvdimm/test/iomap.c:20:\tnfit_test_evaluate_dsm_fn evaluate_dsm;\ntools/testing/nvdimm/test/iomap.c-21-\tstruct list_head list;\n--\ntools/testing/nvdimm/test/iomap.c-25-\ntools/testing/nvdimm/test/iomap.c:26:void nfit_test_setup(nfit_test_lookup_fn lookup,\ntools/testing/nvdimm/test/iomap.c:27:\t\tnfit_test_evaluate_dsm_fn evaluate)\ntools/testing/nvdimm/test/iomap.c-28-{\ntools/testing/nvdimm/test/iomap.c:29:\tiomap_ops.nfit_test_lookup = lookup;\ntools/testing/nvdimm/test/iomap.c-30-\tiomap_ops.evaluate_dsm = evaluate;\n--\ntools/testing/nvdimm/test/iomap.c-32-}\ntools/testing/nvdimm/test/iomap.c:33:EXPORT_SYMBOL(nfit_test_setup);\ntools/testing/nvdimm/test/iomap.c-34-\ntools/testing/nvdimm/test/iomap.c:35:void nfit_test_teardown(void)\ntools/testing/nvdimm/test/iomap.c-36-{\n--\ntools/testing/nvdimm/test/iomap.c-39-}\ntools/testing/nvdimm/test/iomap.c:40:EXPORT_SYMBOL(nfit_test_teardown);\ntools/testing/nvdimm/test/iomap.c-41-\ntools/testing/nvdimm/test/iomap.c:42:static struct nfit_test_resource __get_nfit_res(resource_size_t resource)\ntools/testing/nvdimm/test/iomap.c-43-{\n--\ntools/testing/nvdimm/test/iomap.c-47-\tif (ops)\ntools/testing/nvdimm/test/iomap.c:48:\t\treturn ops-\u003enfit_test_lookup(resource);\ntools/testing/nvdimm/test/iomap.c-49-\treturn NULL;\n--\ntools/testing/nvdimm/test/iomap.c-51-\ntools/testing/nvdimm/test/iomap.c:52:struct nfit_test_resource get_nfit_res(resource_size_t resource)\ntools/testing/nvdimm/test/iomap.c-53-{\ntools/testing/nvdimm/test/iomap.c:54:\tstruct nfit_test_resource res;\ntools/testing/nvdimm/test/iomap.c-55-\n--\ntools/testing/nvdimm/test/iomap.c=62=EXPORT_SYMBOL(get_nfit_res);\ntools/testing/nvdimm/test/iomap.c-63-\ntools/testing/nvdimm/test/iomap.c:64:#define __nfit_test_ioremap(offset, size, fallback_fn) ({\t\t\\\ntools/testing/nvdimm/test/iomap.c:65:\tstruct nfit_test_resource nfit_res = get_nfit_res(offset);\t\\\ntools/testing/nvdimm/test/iomap.c-66-\tnfit_res ?\t\t\t\t\t\t\t\\\n--\ntools/testing/nvdimm/test/iomap.c=73=void __iomem __wrap_devm_ioremap(struct device dev,\n--\ntools/testing/nvdimm/test/iomap.c-75-{\ntools/testing/nvdimm/test/iomap.c:76:\tstruct nfit_test_resource nfit_res = get_nfit_res(offset);\ntools/testing/nvdimm/test/iomap.c-77-\n--\ntools/testing/nvdimm/test/iomap.c=85=void __wrap_devm_memremap(struct device dev, resource_size_t offset,\n--\ntools/testing/nvdimm/test/iomap.c-87-{\ntools/testing/nvdimm/test/iomap.c:88:\tstruct nfit_test_resource nfit_res = get_nfit_res(offset);\ntools/testing/nvdimm/test/iomap.c-89-\n--\ntools/testing/nvdimm/test/iomap.c=94=EXPORT_SYMBOL(__wrap_devm_memremap);\ntools/testing/nvdimm/test/iomap.c-95-\ntools/testing/nvdimm/test/iomap.c:96:static void nfit_test_kill(void _pgmap)\ntools/testing/nvdimm/test/iomap.c-97-{\n--\ntools/testing/nvdimm/test/iomap.c=115=void __wrap_devm_memremap_pages(struct device dev, struct dev_pagemap pgmap)\n--\ntools/testing/nvdimm/test/iomap.c-118-\tresource_size_t offset = pgmap-\u003erange.start;\ntools/testing/nvdimm/test/iomap.c:119:\tstruct nfit_test_resource nfit_res = get_nfit_res(offset);\ntools/testing/nvdimm/test/iomap.c-120-\n--\ntools/testing/nvdimm/test/iomap.c-129-\ntools/testing/nvdimm/test/iomap.c:130:\terror = devm_add_action_or_reset(dev, nfit_test_kill, pgmap);\ntools/testing/nvdimm/test/iomap.c-131-\tif (error)\n--\ntools/testing/nvdimm/test/iomap.c=137=void __wrap_memremap(resource_size_t offset, size_t size,\n--\ntools/testing/nvdimm/test/iomap.c-139-{\ntools/testing/nvdimm/test/iomap.c:140:\tstruct nfit_test_resource nfit_res = get_nfit_res(offset);\ntools/testing/nvdimm/test/iomap.c-141-\n--\ntools/testing/nvdimm/test/iomap.c=148=void __wrap_devm_memunmap(struct device dev, void addr)\ntools/testing/nvdimm/test/iomap.c-149-{\ntools/testing/nvdimm/test/iomap.c:150:\tstruct nfit_test_resource nfit_res = get_nfit_res((long) addr);\ntools/testing/nvdimm/test/iomap.c-151-\n--\ntools/testing/nvdimm/test/iomap.c=158=void __iomem __wrap_ioremap(resource_size_t offset, unsigned long size)\ntools/testing/nvdimm/test/iomap.c-159-{\ntools/testing/nvdimm/test/iomap.c:160:\treturn __nfit_test_ioremap(offset, size, ioremap);\ntools/testing/nvdimm/test/iomap.c-161-}\n--\ntools/testing/nvdimm/test/iomap.c=164=void __iomem __wrap_ioremap_wc(resource_size_t offset, unsigned long size)\ntools/testing/nvdimm/test/iomap.c-165-{\ntools/testing/nvdimm/test/iomap.c:166:\treturn __nfit_test_ioremap(offset, size, ioremap_wc);\ntools/testing/nvdimm/test/iomap.c-167-}\n--\ntools/testing/nvdimm/test/iomap.c=170=void __wrap_iounmap(volatile void __iomem addr)\ntools/testing/nvdimm/test/iomap.c-171-{\ntools/testing/nvdimm/test/iomap.c:172:\tstruct nfit_test_resource nfit_res = get_nfit_res((long) addr);\ntools/testing/nvdimm/test/iomap.c-173-\tif (nfit_res)\n--\ntools/testing/nvdimm/test/iomap.c=179=void __wrap_memunmap(void addr)\ntools/testing/nvdimm/test/iomap.c-180-{\ntools/testing/nvdimm/test/iomap.c:181:\tstruct nfit_test_resource nfit_res = get_nfit_res((long) addr);\ntools/testing/nvdimm/test/iomap.c-182-\n--\ntools/testing/nvdimm/test/iomap.c=187=EXPORT_SYMBOL(__wrap_memunmap);\ntools/testing/nvdimm/test/iomap.c-188-\ntools/testing/nvdimm/test/iomap.c:189:static bool nfit_test_release_region(struct device dev,\ntools/testing/nvdimm/test/iomap.c-190-\t\tstruct resource parent, resource_size_t start,\n--\ntools/testing/nvdimm/test/iomap.c=193=static void nfit_devres_release(struct device dev, void data)\n--\ntools/testing/nvdimm/test/iomap.c-196-\ntools/testing/nvdimm/test/iomap.c:197:\tWARN_ON(!nfit_test_release_region(NULL, \u0026iomem_resource, res-\u003estart,\ntools/testing/nvdimm/test/iomap.c-198-\t\t\tresource_size(res)));\n--\ntools/testing/nvdimm/test/iomap.c=201=static int match(struct device dev, void __res, void match_data)\n--\ntools/testing/nvdimm/test/iomap.c-208-\ntools/testing/nvdimm/test/iomap.c:209:static bool nfit_test_release_region(struct device dev,\ntools/testing/nvdimm/test/iomap.c-210-\t\tstruct resource parent, resource_size_t start,\n--\ntools/testing/nvdimm/test/iomap.c-213-\tif (parent == \u0026iomem_resource) {\ntools/testing/nvdimm/test/iomap.c:214:\t\tstruct nfit_test_resource nfit_res = get_nfit_res(start);\ntools/testing/nvdimm/test/iomap.c-215-\ntools/testing/nvdimm/test/iomap.c-216-\t\tif (nfit_res) {\ntools/testing/nvdimm/test/iomap.c:217:\t\t\tstruct nfit_test_request req;\ntools/testing/nvdimm/test/iomap.c-218-\t\t\tstruct resource res = NULL;\n--\ntools/testing/nvdimm/test/iomap.c-245-\ntools/testing/nvdimm/test/iomap.c:246:static struct resource nfit_test_request_region(struct device dev,\ntools/testing/nvdimm/test/iomap.c-247-\t\tstruct resource parent, resource_size_t start,\n--\ntools/testing/nvdimm/test/iomap.c-249-{\ntools/testing/nvdimm/test/iomap.c:250:\tstruct nfit_test_resource nfit_res;\ntools/testing/nvdimm/test/iomap.c-251-\n--\ntools/testing/nvdimm/test/iomap.c-254-\t\tif (nfit_res) {\ntools/testing/nvdimm/test/iomap.c:255:\t\t\tstruct nfit_test_request req;\ntools/testing/nvdimm/test/iomap.c-256-\t\t\tstruct resource res = NULL;\n--\ntools/testing/nvdimm/test/iomap.c=315=struct resource __wrap___request_region(struct resource parent,\n--\ntools/testing/nvdimm/test/iomap.c-318-{\ntools/testing/nvdimm/test/iomap.c:319:\treturn nfit_test_request_region(NULL, parent, start, n, name, flags);\ntools/testing/nvdimm/test/iomap.c-320-}\n--\ntools/testing/nvdimm/test/iomap.c=339=struct resource __wrap___devm_request_region(struct device dev,\n--\ntools/testing/nvdimm/test/iomap.c-344-\t\treturn NULL;\ntools/testing/nvdimm/test/iomap.c:345:\treturn nfit_test_request_region(dev, parent, start, n, name, 0);\ntools/testing/nvdimm/test/iomap.c-346-}\n--\ntools/testing/nvdimm/test/iomap.c=349=void __wrap___release_region(struct resource parent, resource_size_t start,\n--\ntools/testing/nvdimm/test/iomap.c-351-{\ntools/testing/nvdimm/test/iomap.c:352:\tif (!nfit_test_release_region(NULL, parent, start, n))\ntools/testing/nvdimm/test/iomap.c-353-\t\t__release_region(parent, start, n);\n--\ntools/testing/nvdimm/test/iomap.c=357=void __wrap___devm_release_region(struct device dev, struct resource parent,\n--\ntools/testing/nvdimm/test/iomap.c-359-{\ntools/testing/nvdimm/test/iomap.c:360:\tif (!nfit_test_release_region(dev, parent, start, n))\ntools/testing/nvdimm/test/iomap.c-361-\t\t__devm_release_region(dev, parent, start, n);\n--\ntools/testing/nvdimm/test/iomap.c=365=acpi_status __wrap_acpi_evaluate_object(acpi_handle handle, acpi_string path,\n--\ntools/testing/nvdimm/test/iomap.c-367-{\ntools/testing/nvdimm/test/iomap.c:368:\tstruct nfit_test_resource nfit_res = get_nfit_res((long) handle);\ntools/testing/nvdimm/test/iomap.c-369-\tunion acpi_object obj;\n--\ntools/testing/nvdimm/test/ndtest.c-19-#include \"../watermark.h\"\ntools/testing/nvdimm/test/ndtest.c:20:#include \"nfit_test.h\"\ntools/testing/nvdimm/test/ndtest.c-21-#include \"ndtest.h\"\n--\ntools/testing/nvdimm/test/ndtest.c=44=static const struct class ndtest_dimm_class = {\ntools/testing/nvdimm/test/ndtest.c:45:\t.name = \"nfit_test_dimm\",\ntools/testing/nvdimm/test/ndtest.c-46-};\n--\ntools/testing/nvdimm/test/ndtest.c=244=static int ndtest_ctl(struct nvdimm_bus_descriptor nd_desc,\n--\ntools/testing/nvdimm/test/ndtest.c-285-\ntools/testing/nvdimm/test/ndtest.c:286:static struct nfit_test_resource ndtest_resource_lookup(resource_size_t addr)\ntools/testing/nvdimm/test/ndtest.c-287-{\n--\ntools/testing/nvdimm/test/ndtest.c-290-\tfor (i = 0; i \u003c NUM_INSTANCES; i++) {\ntools/testing/nvdimm/test/ndtest.c:291:\t\tstruct nfit_test_resource n, nfit_res = NULL;\ntools/testing/nvdimm/test/ndtest.c-292-\t\tstruct ndtest_priv t = instances[i];\n--\ntools/testing/nvdimm/test/ndtest.c=319=static void ndtest_release_resource(void data)\ntools/testing/nvdimm/test/ndtest.c-320-{\ntools/testing/nvdimm/test/ndtest.c:321:\tstruct nfit_test_resource res = data;\ntools/testing/nvdimm/test/ndtest.c-322-\n--\ntools/testing/nvdimm/test/ndtest.c=334=static void ndtest_alloc_resource(struct ndtest_priv p, size_t size,\n--\ntools/testing/nvdimm/test/ndtest.c-338-\tvoid buf;\ntools/testing/nvdimm/test/ndtest.c:339:\tstruct nfit_test_resource res;\ntools/testing/nvdimm/test/ndtest.c-340-\tstruct genpool_data_align data = {\n--\ntools/testing/nvdimm/test/ndtest.c=910=static void cleanup_devices(void)\n--\ntools/testing/nvdimm/test/ndtest.c-917-\ntools/testing/nvdimm/test/ndtest.c:918:\tnfit_test_teardown();\ntools/testing/nvdimm/test/ndtest.c-919-\n--\ntools/testing/nvdimm/test/ndtest.c=927=static __init int ndtest_init(void)\n--\ntools/testing/nvdimm/test/ndtest.c-935-\ntools/testing/nvdimm/test/ndtest.c:936:\tnfit_test_setup(ndtest_resource_lookup, NULL);\ntools/testing/nvdimm/test/ndtest.c-937-\n--\ntools/testing/nvdimm/test/nfit.c-22-#include \u003cnd.h\u003e\ntools/testing/nvdimm/test/nfit.c:23:#include \"nfit_test.h\"\ntools/testing/nvdimm/test/nfit.c-24-#include \"../watermark.h\"\n--\ntools/testing/nvdimm/test/nfit.c=95=enum {\n--\ntools/testing/nvdimm/test/nfit.c-113-\ntools/testing/nvdimm/test/nfit.c:114:struct nfit_test_dcr {\ntools/testing/nvdimm/test/nfit.c-115-\t__le64 bdw_addr;\n--\ntools/testing/nvdimm/test/nfit.c=135=static int dimm_fail_cmd_code[ARRAY_SIZE(handle)];\ntools/testing/nvdimm/test/nfit.c:136:struct nfit_test_sec {\ntools/testing/nvdimm/test/nfit.c-137-\tu8 state;\n--\ntools/testing/nvdimm/test/nfit.c=145=static const struct nd_intel_smart smart_def = {\n--\ntools/testing/nvdimm/test/nfit.c-167-\ntools/testing/nvdimm/test/nfit.c:168:struct nfit_test_fw {\ntools/testing/nvdimm/test/nfit.c-169-\tenum intel_fw_update_state state;\n--\ntools/testing/nvdimm/test/nfit.c-178-\ntools/testing/nvdimm/test/nfit.c:179:struct nfit_test {\ntools/testing/nvdimm/test/nfit.c-180-\tstruct acpi_nfit_desc acpi_desc;\n--\ntools/testing/nvdimm/test/nfit.c-197-\tdma_addr_t spa_set_dma;\ntools/testing/nvdimm/test/nfit.c:198:\tstruct nfit_test_dcr dcr;\ntools/testing/nvdimm/test/nfit.c-199-\tdma_addr_t dcr_dma;\ntools/testing/nvdimm/test/nfit.c:200:\tint (alloc)(struct nfit_test t);\ntools/testing/nvdimm/test/nfit.c:201:\tvoid (setup)(struct nfit_test t);\ntools/testing/nvdimm/test/nfit.c-202-\tint setup_hotplug;\n--\ntools/testing/nvdimm/test/nfit.c-214-\tstruct work_struct work;\ntools/testing/nvdimm/test/nfit.c:215:\tstruct nfit_test_fw fw;\ntools/testing/nvdimm/test/nfit.c-216-};\n--\ntools/testing/nvdimm/test/nfit.c=222=static const char zero_key[NVDIMM_PASSPHRASE_LEN];\ntools/testing/nvdimm/test/nfit.c-223-\ntools/testing/nvdimm/test/nfit.c:224:static struct nfit_test to_nfit_test(struct device dev)\ntools/testing/nvdimm/test/nfit.c-225-{\n--\ntools/testing/nvdimm/test/nfit.c-227-\ntools/testing/nvdimm/test/nfit.c:228:\treturn container_of(pdev, struct nfit_test, pdev);\ntools/testing/nvdimm/test/nfit.c-229-}\ntools/testing/nvdimm/test/nfit.c-230-\ntools/testing/nvdimm/test/nfit.c:231:static int nd_intel_test_get_fw_info(struct nfit_test t,\ntools/testing/nvdimm/test/nfit.c-232-\t\tstruct nd_intel_fw_info nd_cmd, unsigned int buf_len,\n--\ntools/testing/nvdimm/test/nfit.c-235-\tstruct device dev = \u0026t-\u003epdev.dev;\ntools/testing/nvdimm/test/nfit.c:236:\tstruct nfit_test_fw fw = \u0026t-\u003efw[idx];\ntools/testing/nvdimm/test/nfit.c-237-\ntools/testing/nvdimm/test/nfit.c:238:\tdev_dbg(dev, \"%s(nfit_test: %p nd_cmd: %p, buf_len: %u, idx: %d\\n\",\ntools/testing/nvdimm/test/nfit.c-239-\t\t\t__func__, t, nd_cmd, buf_len, idx);\n--\ntools/testing/nvdimm/test/nfit.c-256-\ntools/testing/nvdimm/test/nfit.c:257:static int nd_intel_test_start_update(struct nfit_test t,\ntools/testing/nvdimm/test/nfit.c-258-\t\tstruct nd_intel_fw_start nd_cmd, unsigned int buf_len,\n--\ntools/testing/nvdimm/test/nfit.c-261-\tstruct device dev = \u0026t-\u003epdev.dev;\ntools/testing/nvdimm/test/nfit.c:262:\tstruct nfit_test_fw fw = \u0026t-\u003efw[idx];\ntools/testing/nvdimm/test/nfit.c-263-\ntools/testing/nvdimm/test/nfit.c:264:\tdev_dbg(dev, \"%s(nfit_test: %p nd_cmd: %p buf_len: %u idx: %d)\\n\",\ntools/testing/nvdimm/test/nfit.c-265-\t\t\t__func__, t, nd_cmd, buf_len, idx);\n--\ntools/testing/nvdimm/test/nfit.c-286-\ntools/testing/nvdimm/test/nfit.c:287:static int nd_intel_test_send_data(struct nfit_test t,\ntools/testing/nvdimm/test/nfit.c-288-\t\tstruct nd_intel_fw_send_data nd_cmd, unsigned int buf_len,\n--\ntools/testing/nvdimm/test/nfit.c-291-\tstruct device dev = \u0026t-\u003epdev.dev;\ntools/testing/nvdimm/test/nfit.c:292:\tstruct nfit_test_fw fw = \u0026t-\u003efw[idx];\ntools/testing/nvdimm/test/nfit.c-293-\tu32 status = (u32 )\u0026nd_cmd-\u003edata[nd_cmd-\u003elength];\ntools/testing/nvdimm/test/nfit.c-294-\ntools/testing/nvdimm/test/nfit.c:295:\tdev_dbg(dev, \"%s(nfit_test: %p nd_cmd: %p buf_len: %u idx: %d)\\n\",\ntools/testing/nvdimm/test/nfit.c-296-\t\t\t__func__, t, nd_cmd, buf_len, idx);\n--\ntools/testing/nvdimm/test/nfit.c-337-\ntools/testing/nvdimm/test/nfit.c:338:static int nd_intel_test_finish_fw(struct nfit_test t,\ntools/testing/nvdimm/test/nfit.c-339-\t\tstruct nd_intel_fw_finish_update nd_cmd,\n--\ntools/testing/nvdimm/test/nfit.c-342-\tstruct device dev = \u0026t-\u003epdev.dev;\ntools/testing/nvdimm/test/nfit.c:343:\tstruct nfit_test_fw fw = \u0026t-\u003efw[idx];\ntools/testing/nvdimm/test/nfit.c-344-\ntools/testing/nvdimm/test/nfit.c:345:\tdev_dbg(dev, \"%s(nfit_test: %p nd_cmd: %p buf_len: %u idx: %d)\\n\",\ntools/testing/nvdimm/test/nfit.c-346-\t\t\t__func__, t, nd_cmd, buf_len, idx);\n--\ntools/testing/nvdimm/test/nfit.c-388-\ntools/testing/nvdimm/test/nfit.c:389:static int nd_intel_test_finish_query(struct nfit_test t,\ntools/testing/nvdimm/test/nfit.c-390-\t\tstruct nd_intel_fw_finish_query nd_cmd,\n--\ntools/testing/nvdimm/test/nfit.c-393-\tstruct device dev = \u0026t-\u003epdev.dev;\ntools/testing/nvdimm/test/nfit.c:394:\tstruct nfit_test_fw fw = \u0026t-\u003efw[idx];\ntools/testing/nvdimm/test/nfit.c-395-\ntools/testing/nvdimm/test/nfit.c:396:\tdev_dbg(dev, \"%s(nfit_test: %p nd_cmd: %p buf_len: %u idx: %d)\\n\",\ntools/testing/nvdimm/test/nfit.c-397-\t\t\t__func__, t, nd_cmd, buf_len, idx);\n--\ntools/testing/nvdimm/test/nfit.c-450-\ntools/testing/nvdimm/test/nfit.c:451:static int nfit_test_cmd_get_config_size(struct nd_cmd_get_config_size nd_cmd,\ntools/testing/nvdimm/test/nfit.c-452-\t\tunsigned int buf_len)\n--\ntools/testing/nvdimm/test/nfit.c-463-\ntools/testing/nvdimm/test/nfit.c:464:static int nfit_test_cmd_get_config_data(struct nd_cmd_get_config_data_hdr\ntools/testing/nvdimm/test/nfit.c-465-\t\tnd_cmd, unsigned int buf_len, void label)\n--\ntools/testing/nvdimm/test/nfit.c-484-\ntools/testing/nvdimm/test/nfit.c:485:static int nfit_test_cmd_set_config_data(struct nd_cmd_set_config_hdr nd_cmd,\ntools/testing/nvdimm/test/nfit.c-486-\t\tunsigned int buf_len, void label)\n--\ntools/testing/nvdimm/test/nfit.c-509-\ntools/testing/nvdimm/test/nfit.c:510:static int nfit_test_cmd_ars_cap(struct nd_cmd_ars_cap nd_cmd,\ntools/testing/nvdimm/test/nfit.c-511-\t\tunsigned int buf_len)\n--\ntools/testing/nvdimm/test/nfit.c=529=static void post_ars_status(struct ars_state ars_state,\n--\ntools/testing/nvdimm/test/nfit.c-567-\ntools/testing/nvdimm/test/nfit.c:568:static int nfit_test_cmd_ars_start(struct nfit_test t,\ntools/testing/nvdimm/test/nfit.c-569-\t\tstruct ars_state ars_state,\n--\ntools/testing/nvdimm/test/nfit.c-591-\ntools/testing/nvdimm/test/nfit.c:592:static int nfit_test_cmd_ars_status(struct ars_state ars_state,\ntools/testing/nvdimm/test/nfit.c-593-\t\tstruct nd_cmd_ars_status ars_status, unsigned int buf_len,\n--\ntools/testing/nvdimm/test/nfit.c-613-\ntools/testing/nvdimm/test/nfit.c:614:static int nfit_test_cmd_clear_error(struct nfit_test t,\ntools/testing/nvdimm/test/nfit.c-615-\t\tstruct nd_cmd_clear_error clear_err,\n--\ntools/testing/nvdimm/test/nfit.c=637=static int is_region_device(struct device dev)\n--\ntools/testing/nvdimm/test/nfit.c-641-\ntools/testing/nvdimm/test/nfit.c:642:static int nfit_test_search_region_spa(struct device dev, void data)\ntools/testing/nvdimm/test/nfit.c-643-{\n--\ntools/testing/nvdimm/test/nfit.c-661-\ntools/testing/nvdimm/test/nfit.c:662:static int nfit_test_search_spa(struct nvdimm_bus bus,\ntools/testing/nvdimm/test/nfit.c-663-\t\tstruct nd_cmd_translate_spa spa)\n--\ntools/testing/nvdimm/test/nfit.c-676-\tret = device_for_each_child(\u0026bus-\u003edev, \u0026ctx,\ntools/testing/nvdimm/test/nfit.c:677:\t\t\t\tnfit_test_search_region_spa);\ntools/testing/nvdimm/test/nfit.c-678-\n--\ntools/testing/nvdimm/test/nfit.c-702-\ntools/testing/nvdimm/test/nfit.c:703:static int nfit_test_cmd_translate_spa(struct nvdimm_bus bus,\ntools/testing/nvdimm/test/nfit.c-704-\t\tstruct nd_cmd_translate_spa spa, unsigned int buf_len)\n--\ntools/testing/nvdimm/test/nfit.c-708-\ntools/testing/nvdimm/test/nfit.c:709:\tif (nfit_test_search_spa(bus, spa) \u003c 0 \|\| !spa-\u003enum_nvdimms)\ntools/testing/nvdimm/test/nfit.c-710-\t\tspa-\u003estatus = 2;\n--\ntools/testing/nvdimm/test/nfit.c-714-\ntools/testing/nvdimm/test/nfit.c:715:static int nfit_test_cmd_smart(struct nd_intel_smart smart, unsigned int buf_len,\ntools/testing/nvdimm/test/nfit.c-716-\t\tstruct nd_intel_smart smart_data)\n--\ntools/testing/nvdimm/test/nfit.c-723-\ntools/testing/nvdimm/test/nfit.c:724:static int nfit_test_cmd_smart_threshold(\ntools/testing/nvdimm/test/nfit.c-725-\t\tstruct nd_intel_smart_threshold out,\n--\ntools/testing/nvdimm/test/nfit.c=735=static void smart_notify(struct device bus_dev,\n--\ntools/testing/nvdimm/test/nfit.c-760-\ntools/testing/nvdimm/test/nfit.c:761:static int nfit_test_cmd_smart_set_threshold(\ntools/testing/nvdimm/test/nfit.c-762-\t\tstruct nd_intel_smart_set_threshold in,\n--\ntools/testing/nvdimm/test/nfit.c-779-\ntools/testing/nvdimm/test/nfit.c:780:static int nfit_test_cmd_smart_inject(\ntools/testing/nvdimm/test/nfit.c-781-\t\tstruct nd_intel_smart_inject inj,\n--\ntools/testing/nvdimm/test/nfit.c=821=static void uc_error_notify(struct work_struct work)\ntools/testing/nvdimm/test/nfit.c-822-{\ntools/testing/nvdimm/test/nfit.c:823:\tstruct nfit_test t = container_of(work, typeof(t), work);\ntools/testing/nvdimm/test/nfit.c-824-\n--\ntools/testing/nvdimm/test/nfit.c-827-\ntools/testing/nvdimm/test/nfit.c:828:static int nfit_test_cmd_ars_error_inject(struct nfit_test t,\ntools/testing/nvdimm/test/nfit.c-829-\t\tstruct nd_cmd_ars_err_inj err_inj, unsigned int buf_len)\n--\ntools/testing/nvdimm/test/nfit.c-858-\ntools/testing/nvdimm/test/nfit.c:859:static int nfit_test_cmd_ars_inject_clear(struct nfit_test t,\ntools/testing/nvdimm/test/nfit.c-860-\t\tstruct nd_cmd_ars_err_inj_clr err_clr, unsigned int buf_len)\n--\ntools/testing/nvdimm/test/nfit.c-884-\ntools/testing/nvdimm/test/nfit.c:885:static int nfit_test_cmd_ars_inject_status(struct nfit_test t,\ntools/testing/nvdimm/test/nfit.c-886-\t\tstruct nd_cmd_ars_err_inj_stat err_stat,\n--\ntools/testing/nvdimm/test/nfit.c-907-\ntools/testing/nvdimm/test/nfit.c:908:static int nd_intel_test_cmd_set_lss_status(struct nfit_test *t,\n\n" }
35/2	2026/09/25 11:22	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 36394 output: 30 thoughts: 1433 Thoughts: Fuzzing Analysis of NVDIMM/PMEM Changes Okay, so I'm looking at this patch and immediately my brain jumps to `tools/testing/nvdimm`—that's the in-tree unit testing infrastructure for NVDIMM. But wait, we need to think beyond that: what about the production kernel drivers? `CONFIG_BLK_DEV_PMEM` builds `drivers/nvdimm/pmem.c`, right? Can syzkaller, our primary fuzzer, reach `pmem.c`? Syzkaller runs in standard QEMU or GCE VMs. Does standard QEMU or GCE VM have access to a PMEM block device? Does QEMU pass NVDIMM or memmap in standard syzkaller? We need to go back to fundamentals. Let me go back to the triage philosophy outlined. We need to re-read the criteria. The core principle is reachability. The patch fuzzing goal is to find crashes, regressions, exposed latent bugs, and new assertions introduced by the patch. Fuzzing is only useful for code that executes in standard virtualized environments. If the code is unreachable, don't fuzz it. Don't be fooled by "no functional change" or "refactoring" claims. Those can introduce subtle shifts. If reachable executable code is modified, we must fuzz it. Okay, now for the negative criteria. We only return `WorthFuzzing=false` if all modified code falls into these categories. Is it non-kernel, non-executable stuff? No. Is it structurally unreachable hardware? We need to be precise. The definition is vendor-specific PCIe switches, SmartNICs, or GPU drivers requiring physical ASIC/PCIe cards not emulated in standard QEMU. PMEM/NVDIMM does not fall into that. It's not vendor-specific hardware requiring a physical ASIC that QEMU can't emulate. This is not the case here, because, on top of that, the change is in `include/linux/page-flags.h` (Memory management), and `drivers/nvdimm/pmem.c`! Is `include/linux/page-flags.h` a core subsystem? YES! That's the memory management subsystem (`mm/`) defining page flags. The change in `include/linux/page-flags.h` is this: adding `TESTSCFLAG_FALSE(HWPoison, hwpoison)` and changing `drivers/nvdimm/pmem.c` to use `TestClearPageHWPoison(page)`. This is a core memory management change! Therefore, we have a positive criterion! Any change to reachable executable code is to be fuzzed! It includes core subsystems. So, can `virtio-pmem` or `pmem` or `dax` be fuzzed? Let's check. Ah-ha! `CONFIG_VIRTIO_PMEM` exists! There's a virtio driver for pmem, `drivers/nvdimm/virtio_pmem.c`. Bingo!
36/2	2026/09/25 11:22	tool	grepper	0m Args: { "Expression": "virtio_pmem", "PathPrefix": "drivers/nvdimm" } Results: { "Output": "drivers/nvdimm/Makefile=6=obj-$(CONFIG_OF_PMEM) += of_pmem.o\ndrivers/nvdimm/Makefile:7:obj-$(CONFIG_VIRTIO_PMEM) += virtio_pmem.o nd_virtio.o\ndrivers/nvdimm/Makefile-8-obj-$(CONFIG_RAMDAX) += ramdax.o\n--\ndrivers/nvdimm/nd_virtio.c-2-/\ndrivers/nvdimm/nd_virtio.c:3: virtio_pmem.c: Virtio pmem Driver\ndrivers/nvdimm/nd_virtio.c-4- \n--\ndrivers/nvdimm/nd_virtio.c-8- /\ndrivers/nvdimm/nd_virtio.c:9:#include \"virtio_pmem.h\"\ndrivers/nvdimm/nd_virtio.c-10-#include \"nd.h\"\ndrivers/nvdimm/nd_virtio.c-11-\ndrivers/nvdimm/nd_virtio.c:12:struct virtio_pmem_flush_work {\ndrivers/nvdimm/nd_virtio.c-13-\tstruct work_struct work;\n--\ndrivers/nvdimm/nd_virtio.c-17-\ndrivers/nvdimm/nd_virtio.c:18:static void virtio_pmem_req_release(struct kref kref)\ndrivers/nvdimm/nd_virtio.c-19-{\ndrivers/nvdimm/nd_virtio.c:20:\tstruct virtio_pmem_request req;\ndrivers/nvdimm/nd_virtio.c-21-\ndrivers/nvdimm/nd_virtio.c:22:\treq = container_of(kref, struct virtio_pmem_request, kref);\ndrivers/nvdimm/nd_virtio.c-23-\tkfree(req);\n--\ndrivers/nvdimm/nd_virtio.c-25-\ndrivers/nvdimm/nd_virtio.c:26:static void virtio_pmem_signal_done(struct virtio_pmem_request req)\ndrivers/nvdimm/nd_virtio.c-27-{\ndrivers/nvdimm/nd_virtio.c:28:\t/ Pairs with smp_load_acquire() in virtio_pmem_req_done(). /\ndrivers/nvdimm/nd_virtio.c-29-\tsmp_store_release(\u0026req-\u003edone, true);\n--\ndrivers/nvdimm/nd_virtio.c-32-\ndrivers/nvdimm/nd_virtio.c:33:static bool virtio_pmem_req_done(struct virtio_pmem_request req)\ndrivers/nvdimm/nd_virtio.c-34-{\ndrivers/nvdimm/nd_virtio.c:35:\t/* Pairs with smp_store_release() in virtio_pmem_signal_done(). /\ndrivers/nvdimm/nd_virtio.c-36-\treturn smp_load_acquire(\u0026req-\u003edone);\n--\ndrivers/nvdimm/nd_virtio.c-38-\ndrivers/nvdimm/nd_virtio.c:39:static void virtio_pmem_complete_err(struct virtio_pmem_request req)\ndrivers/nvdimm/nd_virtio.c-40-{\ndrivers/nvdimm/nd_virtio.c-41-\treq-\u003eresp.ret = cpu_to_le32(1);\ndrivers/nvdimm/nd_virtio.c:42:\tvirtio_pmem_signal_done(req);\ndrivers/nvdimm/nd_virtio.c-43-}\ndrivers/nvdimm/nd_virtio.c-44-\ndrivers/nvdimm/nd_virtio.c:45:static void virtio_pmem_wake_one_waiter(struct virtio_pmem vpmem)\ndrivers/nvdimm/nd_virtio.c-46-{\ndrivers/nvdimm/nd_virtio.c:47:\tstruct virtio_pmem_request req_buf;\ndrivers/nvdimm/nd_virtio.c-48-\n--\ndrivers/nvdimm/nd_virtio.c-52-\treq_buf = list_first_entry(\u0026vpmem-\u003ereq_list,\ndrivers/nvdimm/nd_virtio.c:53:\t\t\t\t struct virtio_pmem_request, list);\ndrivers/nvdimm/nd_virtio.c-54-\tlist_del_init(\u0026req_buf-\u003elist);\n--\ndrivers/nvdimm/nd_virtio.c-58-\ndrivers/nvdimm/nd_virtio.c:59:static void virtio_pmem_wake_all_waiters(struct virtio_pmem vpmem)\ndrivers/nvdimm/nd_virtio.c-60-{\ndrivers/nvdimm/nd_virtio.c:61:\tstruct virtio_pmem_request req, tmp;\ndrivers/nvdimm/nd_virtio.c-62-\n--\ndrivers/nvdimm/nd_virtio.c-69-\ndrivers/nvdimm/nd_virtio.c:70:static void virtio_pmem_clear_inflight(struct virtio_pmem vpmem,\ndrivers/nvdimm/nd_virtio.c:71:\t\t\t\t struct virtio_pmem_request req)\ndrivers/nvdimm/nd_virtio.c-72-{\n--\ndrivers/nvdimm/nd_virtio.c-76-\ndrivers/nvdimm/nd_virtio.c:77:static void virtio_pmem_wake_inflight(struct virtio_pmem vpmem)\ndrivers/nvdimm/nd_virtio.c-78-{\ndrivers/nvdimm/nd_virtio.c:79:\tstruct virtio_pmem_request req = vpmem-\u003ereq_inflight;\ndrivers/nvdimm/nd_virtio.c-80-\n--\ndrivers/nvdimm/nd_virtio.c-84-\ndrivers/nvdimm/nd_virtio.c:85:void virtio_pmem_mark_broken(struct virtio_pmem vpmem)\ndrivers/nvdimm/nd_virtio.c-86-{\n--\ndrivers/nvdimm/nd_virtio.c-91-\ndrivers/nvdimm/nd_virtio.c:92:\tvirtio_pmem_wake_inflight(vpmem);\ndrivers/nvdimm/nd_virtio.c:93:\tvirtio_pmem_wake_all_waiters(vpmem);\ndrivers/nvdimm/nd_virtio.c-94-}\ndrivers/nvdimm/nd_virtio.c:95:EXPORT_SYMBOL_GPL(virtio_pmem_mark_broken);\ndrivers/nvdimm/nd_virtio.c-96-\ndrivers/nvdimm/nd_virtio.c:97:void virtio_pmem_drain(struct virtio_pmem vpmem)\ndrivers/nvdimm/nd_virtio.c-98-{\ndrivers/nvdimm/nd_virtio.c:99:\tstruct virtio_pmem_request req;\ndrivers/nvdimm/nd_virtio.c-100-\tunsigned int len;\n--\ndrivers/nvdimm/nd_virtio.c-105-\twhile ((req = virtqueue_get_buf(vpmem-\u003ereq_vq, \u0026len)) != NULL) {\ndrivers/nvdimm/nd_virtio.c:106:\t\tvirtio_pmem_clear_inflight(vpmem, req);\ndrivers/nvdimm/nd_virtio.c:107:\t\tvirtio_pmem_complete_err(req);\ndrivers/nvdimm/nd_virtio.c:108:\t\tkref_put(\u0026req-\u003ekref, virtio_pmem_req_release);\ndrivers/nvdimm/nd_virtio.c-109-\t}\n--\ndrivers/nvdimm/nd_virtio.c-111-\twhile ((req = virtqueue_detach_unused_buf(vpmem-\u003ereq_vq)) != NULL) {\ndrivers/nvdimm/nd_virtio.c:112:\t\tvirtio_pmem_clear_inflight(vpmem, req);\ndrivers/nvdimm/nd_virtio.c:113:\t\tvirtio_pmem_complete_err(req);\ndrivers/nvdimm/nd_virtio.c:114:\t\tkref_put(\u0026req-\u003ekref, virtio_pmem_req_release);\ndrivers/nvdimm/nd_virtio.c-115-\t}\ndrivers/nvdimm/nd_virtio.c-116-}\ndrivers/nvdimm/nd_virtio.c:117:EXPORT_SYMBOL_GPL(virtio_pmem_drain);\ndrivers/nvdimm/nd_virtio.c-118-\ndrivers/nvdimm/nd_virtio.c-119- /* The interrupt handler /\ndrivers/nvdimm/nd_virtio.c:120:void virtio_pmem_host_ack(struct virtqueue vq)\ndrivers/nvdimm/nd_virtio.c-121-{\ndrivers/nvdimm/nd_virtio.c:122:\tstruct virtio_pmem vpmem = vq-\u003evdev-\u003epriv;\ndrivers/nvdimm/nd_virtio.c:123:\tstruct virtio_pmem_request req_data;\ndrivers/nvdimm/nd_virtio.c-124-\tunsigned long flags;\n--\ndrivers/nvdimm/nd_virtio.c-128-\twhile ((req_data = virtqueue_get_buf(vq, \u0026len)) != NULL) {\ndrivers/nvdimm/nd_virtio.c:129:\t\tvirtio_pmem_clear_inflight(vpmem, req_data);\ndrivers/nvdimm/nd_virtio.c:130:\t\tvirtio_pmem_wake_one_waiter(vpmem);\ndrivers/nvdimm/nd_virtio.c-131-\t\tif (READ_ONCE(vpmem-\u003ebroken))\ndrivers/nvdimm/nd_virtio.c:132:\t\t\tvirtio_pmem_complete_err(req_data);\ndrivers/nvdimm/nd_virtio.c-133-\t\telse\ndrivers/nvdimm/nd_virtio.c:134:\t\t\tvirtio_pmem_signal_done(req_data);\ndrivers/nvdimm/nd_virtio.c:135:\t\tkref_put(\u0026req_data-\u003ekref, virtio_pmem_req_release);\ndrivers/nvdimm/nd_virtio.c-136-\t}\n--\ndrivers/nvdimm/nd_virtio.c-138-}\ndrivers/nvdimm/nd_virtio.c:139:EXPORT_SYMBOL_GPL(virtio_pmem_host_ack);\ndrivers/nvdimm/nd_virtio.c-140-\ndrivers/nvdimm/nd_virtio.c-141- /* The request submission function /\ndrivers/nvdimm/nd_virtio.c:142:static int virtio_pmem_flush(struct nd_region nd_region)\ndrivers/nvdimm/nd_virtio.c-143-{\ndrivers/nvdimm/nd_virtio.c-144-\tstruct virtio_device vdev = nd_region-\u003eprovider_data;\ndrivers/nvdimm/nd_virtio.c:145:\tstruct virtio_pmem vpmem = vdev-\u003epriv;\ndrivers/nvdimm/nd_virtio.c:146:\tstruct virtio_pmem_request req_data;\ndrivers/nvdimm/nd_virtio.c-147-\tstruct scatterlist sgs[2], sg, ret;\n--\ndrivers/nvdimm/nd_virtio.c-226-\tif (err == -EIO \|\| virtqueue_is_broken(vpmem-\u003ereq_vq))\ndrivers/nvdimm/nd_virtio.c:227:\t\tvirtio_pmem_mark_broken(vpmem);\ndrivers/nvdimm/nd_virtio.c-228-\n--\ndrivers/nvdimm/nd_virtio.c-232-\t\tif (!err1)\ndrivers/nvdimm/nd_virtio.c:233:\t\t\tvirtio_pmem_mark_broken(vpmem);\ndrivers/nvdimm/nd_virtio.c-234-\t}\n--\ndrivers/nvdimm/nd_virtio.c-245-\t\twait_event(req_data-\u003ehost_acked,\ndrivers/nvdimm/nd_virtio.c:246:\t\t\t virtio_pmem_req_done(req_data) \|\|\ndrivers/nvdimm/nd_virtio.c-247-\t\t\t READ_ONCE(vpmem-\u003ebroken));\ndrivers/nvdimm/nd_virtio.c:248:\t\tif (virtio_pmem_req_done(req_data))\ndrivers/nvdimm/nd_virtio.c-249-\t\t\terr = le32_to_cpu(req_data-\u003eresp.ret);\n--\ndrivers/nvdimm/nd_virtio.c-253-\ndrivers/nvdimm/nd_virtio.c:254:\tkref_put(\u0026req_data-\u003ekref, virtio_pmem_req_release);\ndrivers/nvdimm/nd_virtio.c-255-\treturn err;\n--\ndrivers/nvdimm/nd_virtio.c-257-\ndrivers/nvdimm/nd_virtio.c:258:static void virtio_pmem_flush_work(struct work_struct work)\ndrivers/nvdimm/nd_virtio.c-259-{\ndrivers/nvdimm/nd_virtio.c:260:\tstruct virtio_pmem_flush_work flush;\ndrivers/nvdimm/nd_virtio.c-261-\tint err;\ndrivers/nvdimm/nd_virtio.c-262-\ndrivers/nvdimm/nd_virtio.c:263:\tflush = container_of(work, struct virtio_pmem_flush_work, work);\ndrivers/nvdimm/nd_virtio.c:264:\terr = virtio_pmem_flush(flush-\u003end_region);\ndrivers/nvdimm/nd_virtio.c-265-\tif (err \u003e 0)\n--\ndrivers/nvdimm/nd_virtio.c=274=int async_pmem_flush(struct nd_region nd_region, struct bio bio)\n--\ndrivers/nvdimm/nd_virtio.c-276-\tstruct virtio_device vdev = nd_region-\u003eprovider_data;\ndrivers/nvdimm/nd_virtio.c:277:\tstruct virtio_pmem vpmem = vdev-\u003epriv;\ndrivers/nvdimm/nd_virtio.c:278:\tstruct virtio_pmem_flush_work flush;\ndrivers/nvdimm/nd_virtio.c-279-\tunsigned long flags;\n--\ndrivers/nvdimm/nd_virtio.c-286-\ndrivers/nvdimm/nd_virtio.c:287:\t\tINIT_WORK(\u0026flush-\u003ework, virtio_pmem_flush_work);\ndrivers/nvdimm/nd_virtio.c-288-\t\tflush-\u003end_region = nd_region;\n--\ndrivers/nvdimm/nd_virtio.c-301-\ndrivers/nvdimm/nd_virtio.c:302:\terr = virtio_pmem_flush(nd_region);\ndrivers/nvdimm/nd_virtio.c-303-\tif (err \u003e 0)\n--\ndrivers/nvdimm/virtio_pmem.c-2-/\ndrivers/nvdimm/virtio_pmem.c:3: * virtio_pmem.c: Virtio pmem Driver\ndrivers/nvdimm/virtio_pmem.c-4- \n--\ndrivers/nvdimm/virtio_pmem.c-8- /\ndrivers/nvdimm/virtio_pmem.c:9:#include \"virtio_pmem.h\"\ndrivers/nvdimm/virtio_pmem.c-10-#include \"nd.h\"\n--\ndrivers/nvdimm/virtio_pmem.c=12=static struct virtio_device_id id_table[] = {\n--\ndrivers/nvdimm/virtio_pmem.c-17- /* Initialize virt queue /\ndrivers/nvdimm/virtio_pmem.c:18:static int init_vq(struct virtio_pmem vpmem)\ndrivers/nvdimm/virtio_pmem.c-19-{\n--\ndrivers/nvdimm/virtio_pmem.c-23-\tvpmem-\u003ereq_vq = virtio_find_single_vq(vpmem-\u003evdev,\ndrivers/nvdimm/virtio_pmem.c:24:\t\t\t\t\tvirtio_pmem_host_ack, \"flush_queue\");\ndrivers/nvdimm/virtio_pmem.c-25-\tif (IS_ERR(vpmem-\u003ereq_vq)) {\n--\ndrivers/nvdimm/virtio_pmem.c-38-\ndrivers/nvdimm/virtio_pmem.c:39:static void virtio_pmem_del_vqs(struct virtio_pmem vpmem)\ndrivers/nvdimm/virtio_pmem.c-40-{\n--\ndrivers/nvdimm/virtio_pmem.c-47-\ndrivers/nvdimm/virtio_pmem.c:48:static int virtio_pmem_validate(struct virtio_device vdev)\ndrivers/nvdimm/virtio_pmem.c-49-{\n--\ndrivers/nvdimm/virtio_pmem.c-61-\ndrivers/nvdimm/virtio_pmem.c:62:static int virtio_pmem_probe(struct virtio_device vdev)\ndrivers/nvdimm/virtio_pmem.c-63-{\n--\ndrivers/nvdimm/virtio_pmem.c-65-\tstruct nd_region nd_region;\ndrivers/nvdimm/virtio_pmem.c:66:\tstruct virtio_pmem vpmem;\ndrivers/nvdimm/virtio_pmem.c-67-\tstruct resource res;\n--\ndrivers/nvdimm/virtio_pmem.c-103-\t} else {\ndrivers/nvdimm/virtio_pmem.c:104:\t\tvirtio_cread_le(vpmem-\u003evdev, struct virtio_pmem_config,\ndrivers/nvdimm/virtio_pmem.c-105-\t\t\t\tstart, \u0026vpmem-\u003estart);\ndrivers/nvdimm/virtio_pmem.c:106:\t\tvirtio_cread_le(vpmem-\u003evdev, struct virtio_pmem_config,\ndrivers/nvdimm/virtio_pmem.c-107-\t\t\t\tsize, \u0026vpmem-\u003esize);\n--\ndrivers/nvdimm/virtio_pmem.c-155-out_vq:\ndrivers/nvdimm/virtio_pmem.c:156:\tvirtio_pmem_del_vqs(vpmem);\ndrivers/nvdimm/virtio_pmem.c-157-out_wq:\n--\ndrivers/nvdimm/virtio_pmem.c-162-\ndrivers/nvdimm/virtio_pmem.c:163:static void virtio_pmem_remove(struct virtio_device vdev)\ndrivers/nvdimm/virtio_pmem.c-164-{\ndrivers/nvdimm/virtio_pmem.c-165-\tstruct nvdimm_bus nvdimm_bus = dev_get_drvdata(\u0026vdev-\u003edev);\ndrivers/nvdimm/virtio_pmem.c:166:\tstruct virtio_pmem vpmem = vdev-\u003epriv;\ndrivers/nvdimm/virtio_pmem.c-167-\tunsigned long flags;\n--\ndrivers/nvdimm/virtio_pmem.c-169-\tspin_lock_irqsave(\u0026vpmem-\u003epmem_lock, flags);\ndrivers/nvdimm/virtio_pmem.c:170:\tvirtio_pmem_mark_broken(vpmem);\ndrivers/nvdimm/virtio_pmem.c-171-\tspin_unlock_irqrestore(\u0026vpmem-\u003epmem_lock, flags);\n--\ndrivers/nvdimm/virtio_pmem.c-176-\tspin_lock_irqsave(\u0026vpmem-\u003epmem_lock, flags);\ndrivers/nvdimm/virtio_pmem.c:177:\tvirtio_pmem_drain(vpmem);\ndrivers/nvdimm/virtio_pmem.c-178-\tspin_unlock_irqrestore(\u0026vpmem-\u003epmem_lock, flags);\n--\ndrivers/nvdimm/virtio_pmem.c-180-\tnvdimm_bus_unregister(nvdimm_bus);\ndrivers/nvdimm/virtio_pmem.c:181:\tvirtio_pmem_del_vqs(vpmem);\ndrivers/nvdimm/virtio_pmem.c-182-\tdestroy_workqueue(vpmem-\u003eflush_wq);\n--\ndrivers/nvdimm/virtio_pmem.c-184-\ndrivers/nvdimm/virtio_pmem.c:185:static int virtio_pmem_freeze(struct virtio_device vdev)\ndrivers/nvdimm/virtio_pmem.c-186-{\ndrivers/nvdimm/virtio_pmem.c:187:\tstruct virtio_pmem vpmem = vdev-\u003epriv;\ndrivers/nvdimm/virtio_pmem.c-188-\tunsigned long flags;\n--\ndrivers/nvdimm/virtio_pmem.c-190-\tspin_lock_irqsave(\u0026vpmem-\u003epmem_lock, flags);\ndrivers/nvdimm/virtio_pmem.c:191:\tvirtio_pmem_mark_broken(vpmem);\ndrivers/nvdimm/virtio_pmem.c-192-\tspin_unlock_irqrestore(\u0026vpmem-\u003epmem_lock, flags);\n--\ndrivers/nvdimm/virtio_pmem.c-197-\tspin_lock_irqsave(\u0026vpmem-\u003epmem_lock, flags);\ndrivers/nvdimm/virtio_pmem.c:198:\tvirtio_pmem_drain(vpmem);\ndrivers/nvdimm/virtio_pmem.c-199-\tspin_unlock_irqrestore(\u0026vpmem-\u003epmem_lock, flags);\ndrivers/nvdimm/virtio_pmem.c-200-\ndrivers/nvdimm/virtio_pmem.c:201:\tvirtio_pmem_del_vqs(vpmem);\ndrivers/nvdimm/virtio_pmem.c-202-\n--\ndrivers/nvdimm/virtio_pmem.c-205-\ndrivers/nvdimm/virtio_pmem.c:206:static int virtio_pmem_restore(struct virtio_device vdev)\ndrivers/nvdimm/virtio_pmem.c-207-{\n--\ndrivers/nvdimm/virtio_pmem.c=220=static unsigned int features[] = {\n--\ndrivers/nvdimm/virtio_pmem.c-223-\ndrivers/nvdimm/virtio_pmem.c:224:static struct virtio_driver virtio_pmem_driver = {\ndrivers/nvdimm/virtio_pmem.c-225-\t.feature_table\t\t= features,\n--\ndrivers/nvdimm/virtio_pmem.c-228-\t.id_table\t\t= id_table,\ndrivers/nvdimm/virtio_pmem.c:229:\t.validate\t\t= virtio_pmem_validate,\ndrivers/nvdimm/virtio_pmem.c:230:\t.probe\t\t\t= virtio_pmem_probe,\ndrivers/nvdimm/virtio_pmem.c:231:\t.remove\t\t\t= virtio_pmem_remove,\ndrivers/nvdimm/virtio_pmem.c:232:\t.freeze\t\t\t= virtio_pmem_freeze,\ndrivers/nvdimm/virtio_pmem.c:233:\t.restore\t\t= virtio_pmem_restore,\ndrivers/nvdimm/virtio_pmem.c-234-};\ndrivers/nvdimm/virtio_pmem.c-235-\ndrivers/nvdimm/virtio_pmem.c:236:module_virtio_driver(virtio_pmem_driver);\ndrivers/nvdimm/virtio_pmem.c-237-MODULE_DEVICE_TABLE(virtio, id_table);\n--\ndrivers/nvdimm/virtio_pmem.h-2-/\ndrivers/nvdimm/virtio_pmem.h:3: * virtio_pmem.h: virtio pmem Driver\ndrivers/nvdimm/virtio_pmem.h-4- \n--\ndrivers/nvdimm/virtio_pmem.h-14-#include \u003clinux/module.h\u003e\ndrivers/nvdimm/virtio_pmem.h:15:#include \u003cuapi/linux/virtio_pmem.h\u003e\ndrivers/nvdimm/virtio_pmem.h-16-#include \u003clinux/kref.h\u003e\n--\ndrivers/nvdimm/virtio_pmem.h-21-\ndrivers/nvdimm/virtio_pmem.h:22:struct virtio_pmem_request {\ndrivers/nvdimm/virtio_pmem.h-23-\tstruct kref kref;\n--\ndrivers/nvdimm/virtio_pmem.h-33-\ndrivers/nvdimm/virtio_pmem.h:34:\tstruct virtio_pmem_req req;\ndrivers/nvdimm/virtio_pmem.h-35-\t__dma_from_device_group_begin(resp);\ndrivers/nvdimm/virtio_pmem.h:36:\tstruct virtio_pmem_resp resp;\ndrivers/nvdimm/virtio_pmem.h-37-\t__dma_from_device_group_end(resp);\n--\ndrivers/nvdimm/virtio_pmem.h-39-\ndrivers/nvdimm/virtio_pmem.h:40:struct virtio_pmem {\ndrivers/nvdimm/virtio_pmem.h-41-\tstruct virtio_device vdev;\n--\ndrivers/nvdimm/virtio_pmem.h-59-\t/* Request currently owned by the virtqueue. /\ndrivers/nvdimm/virtio_pmem.h:60:\tstruct virtio_pmem_request req_inflight;\ndrivers/nvdimm/virtio_pmem.h-61-\n--\ndrivers/nvdimm/virtio_pmem.h-72-\ndrivers/nvdimm/virtio_pmem.h:73:void virtio_pmem_host_ack(struct virtqueue vq);\ndrivers/nvdimm/virtio_pmem.h:74:void virtio_pmem_mark_broken(struct virtio_pmem vpmem);\ndrivers/nvdimm/virtio_pmem.h:75:void virtio_pmem_drain(struct virtio_pmem vpmem);\ndrivers/nvdimm/virtio_pmem.h-76-int async_pmem_flush(struct nd_region nd_region, struct bio *bio);\n" }
37/2	2026/09/25 11:22	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 45651 output: 52 thoughts: 803 Thoughts: Fuzzing Decision for virtio_pmem Patch Okay, let's break this down. First, this patch deals with `virtio_pmem`, which registers a region, binds to `nd_pmem`, and ultimately leverages `pmem.c`. I need to consider all the different ways a virtio device can be instantiated, including standard QEMU, syzkaller's emulation, or through netlink/driver binds. The patch also modifies `include/linux/page-flags.h` and `drivers/nvdimm/pmem.c`, which raises my immediate attention. Now, let's apply the fuzzing rules: 1. Core Triage Philosophy: I can't just blindly trust claims of "no functional change" or "refactoring." Code refactorings, especially those touching core subsystems, are notorious for introducing subtle bugs or revealing latent issues. This is a must-fuzz situation if I see refactored code that's reachable. 2. *Negative Criteria (When to not* fuzz):** I only exempt patches when all modifications fall into strictly non-executable changes, unreachable hardware, or teardown paths. 3. Positive Criteria (When to fuzz): I'm fuzzing if the patch touches reachable executable code, especially within core subsystems, refactorings, or reachable drivers/protocols. Here's my assessment: * The patch modifies `include/linux/page-flags.h` which directly relates to core memory management (`mm/`) and introduces a new flag `TESTSCFLAG_FALSE(HWPoison, hwpoison)`. This is definitely a core subsystem change. * The patch refactors `pmem_mkpage_present()` in `drivers/nvdimm/pmem.c`, removing a local wrapper and directly using `TestClearPageHWPoison(page)`. This is a refactoring of reachable code. * The PMEM driver is absolutely reachable. It's accessible via `virtio-pmem` on the `virtio` virtual bus, plus ACPI NFIT or memmap/e820 in QEMU. That covers a few potential trigger points. * None of the negative criteria apply. This is kernel code, within an executable path (`pmem_mkpage_present` in I/O operations), not a teardown path, and it's not specific to some arcane hardware. Therefore, `WorthFuzzing` is true. This patch warrants fuzzing. Now, I need to define the `FocusSymbols`. What functions are most critical? I need to focus on the functions that are touched or directly executing the modified logic. Looking at `pmem.c`: * `pmem_mkpage_present` (static) is touched directly in the patch. * `__pmem_clear_poison` (static) * `pmem_clear_poison` (static) * `pmem_do_write` (static) * `pmem_recovery_write` (static) * `pmem_submit_bio` (static, is the block device entry point). But that's not the whole story... What aren't static or entrypoint functions? Those are the keys. Now, I will check what functions in `pmem.c` are exported, non-static, or direct callers.
38/2	2026/09/25 11:22	tool	grepper	0m Args: { "Expression": "pmem_mkpage_present\|__pmem_clear_poison\|pmem_clear_poison", "PathPrefix": "drivers/nvdimm/pmem.c" } Results: { "Output": "drivers/nvdimm/pmem.c=58=static phys_addr_t to_offset(struct pmem_device pmem, sector_t sector)\n--\ndrivers/nvdimm/pmem.c-62-\ndrivers/nvdimm/pmem.c:63:static void pmem_mkpage_present(struct pmem_device pmem, phys_addr_t offset,\ndrivers/nvdimm/pmem.c-64-\t\tunsigned int len)\n--\ndrivers/nvdimm/pmem.c=88=static void pmem_clear_bb(struct pmem_device pmem, sector_t sector, long blks)\n--\ndrivers/nvdimm/pmem.c-96-\ndrivers/nvdimm/pmem.c:97:static long __pmem_clear_poison(struct pmem_device pmem,\ndrivers/nvdimm/pmem.c-98-\t\tphys_addr_t offset, unsigned int len)\n--\ndrivers/nvdimm/pmem.c-103-\tif (cleared \u003e 0) {\ndrivers/nvdimm/pmem.c:104:\t\tpmem_mkpage_present(pmem, offset, cleared);\ndrivers/nvdimm/pmem.c-105-\t\tarch_invalidate_pmem(pmem-\u003evirt_addr + offset, len);\n--\ndrivers/nvdimm/pmem.c-109-\ndrivers/nvdimm/pmem.c:110:static blk_status_t pmem_clear_poison(struct pmem_device pmem,\ndrivers/nvdimm/pmem.c-111-\t\tphys_addr_t offset, unsigned int len)\ndrivers/nvdimm/pmem.c-112-{\ndrivers/nvdimm/pmem.c:113:\tlong cleared = __pmem_clear_poison(pmem, offset, len);\ndrivers/nvdimm/pmem.c-114-\n--\ndrivers/nvdimm/pmem.c=180=static blk_status_t pmem_do_write(struct pmem_device pmem,\n--\ndrivers/nvdimm/pmem.c-187-\tif (unlikely(is_bad_pmem(\u0026pmem-\u003ebb, sector, len))) {\ndrivers/nvdimm/pmem.c:188:\t\tblk_status_t rc = pmem_clear_poison(pmem, pmem_off, len);\ndrivers/nvdimm/pmem.c-189-\n--\ndrivers/nvdimm/pmem.c=340=static size_t pmem_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff,\n--\ndrivers/nvdimm/pmem.c-364-\tpmem_off = PFN_PHYS(pgoff) + pmem-\u003edata_offset;\ndrivers/nvdimm/pmem.c:365:\tcleared = __pmem_clear_poison(pmem, pmem_off, len);\ndrivers/nvdimm/pmem.c-366-\tif (cleared \u003e 0 \u0026\u0026 cleared \u003c len) {\n" }
39/2	2026/09/25 11:22	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 48046 output: 38 thoughts: 469 Thoughts: Analyzing Symbol Coverage for Persistent Memory Operations Okay, let's break this down. My initial question was, who's calling `pmem_mkpage_present`? I know `__pmem_clear_poison` calls it, which itself is called by `pmem_clear_poison`. That then gets called by `pmem_do_write`, which is called by `pmem_submit_bio`. And, I also see `pmem_recovery_write` calls `__pmem_clear_poison`. This is about coverage, so this is good to know. Now, I need to make sure I'm approaching this correctly, and I remember something about static functions. Can I use symbol coverage filters on static functions within `.c` files? I recall from Section 4 that compiler-inlined static functions defined in headers don't have distinct symbols in `vmlinux`, so you can't target them directly with coverage filters. That makes sense; inline functions lose their distinct identity. It says to identify non-static callers that exercise these static inline functions. But, hang on... static functions in `.c` files (unless inlined by the compiler) do have symbols. So functions like `pmem_mkpage_present` and `pmem_clear_poison` are fine. The key, it seems, is making sure we have their callers to cover them properly. Seeing the full call chain with functions like `pmem_submit_bio`, `pmem_recovery_write`, and `pmem_do_write` is actually ideal in this scenario. These are the entry points. Just to be thorough, I'm going to scan the surrounding code in `drivers/nvdimm/pmem.c` around lines 200-240 and 340-380 to see if I'm missing any related calls or functionality. Gotta be sure I'm covering everything.
40/2	2026/09/25 11:22	tool	read-file	0m Args: { "File": "drivers/nvdimm/pmem.c", "FirstLine": 180, "LineCount": 60 } Results: { "Contents": " 180:\tstatic blk_status_t pmem_do_write(struct pmem_device pmem,\n 181:\t\t\t\tstruct page page, unsigned int page_off,\n 182:\t\t\t\tsector_t sector, unsigned int len)\n 183:\t{\n 184:\t\tphys_addr_t pmem_off = to_offset(pmem, sector);\n 185:\t\tvoid pmem_addr = pmem-\u003evirt_addr + pmem_off;\n 186:\t\n 187:\t\tif (unlikely(is_bad_pmem(\u0026pmem-\u003ebb, sector, len))) {\n 188:\t\t\tblk_status_t rc = pmem_clear_poison(pmem, pmem_off, len);\n 189:\t\n 190:\t\t\tif (rc != BLK_STS_OK)\n 191:\t\t\t\treturn rc;\n 192:\t\t}\n 193:\t\n 194:\t\tflush_dcache_page(page);\n 195:\t\twrite_pmem(pmem_addr, page, page_off, len);\n 196:\t\n 197:\t\treturn BLK_STS_OK;\n 198:\t}\n 199:\t\n 200:\tstatic void pmem_submit_bio(struct bio bio)\n 201:\t{\n 202:\t\tint ret = 0;\n 203:\t\tblk_status_t rc = 0;\n 204:\t\tbool do_acct;\n 205:\t\tunsigned long start;\n 206:\t\tstruct bio_vec bvec;\n 207:\t\tstruct bvec_iter iter;\n 208:\t\tstruct pmem_device pmem = bio-\u003ebi_bdev-\u003ebd_disk-\u003eprivate_data;\n 209:\t\tstruct nd_region nd_region = to_region(pmem);\n 210:\t\n 211:\t\tif (bio-\u003ebi_opf \u0026 REQ_PREFLUSH) {\n 212:\t\t\tret = nvdimm_flush(nd_region, NULL);\n 213:\t\t\tif (ret) {\n 214:\t\t\t\tbio-\u003ebi_status = errno_to_blk_status(ret);\n 215:\t\t\t\tbio_endio(bio);\n 216:\t\t\t\treturn;\n 217:\t\t\t}\n 218:\t\t}\n 219:\t\n 220:\t\tif (bio_has_data(bio)) {\n 221:\t\t\tdo_acct = blk_queue_io_stat(bio-\u003ebi_bdev-\u003ebd_disk-\u003equeue);\n 222:\t\t\tif (do_acct)\n 223:\t\t\t\tstart = bio_start_io_acct(bio);\n 224:\t\t\tbio_for_each_segment(bvec, bio, iter) {\n 225:\t\t\t\tif (op_is_write(bio_op(bio)))\n 226:\t\t\t\t\trc = pmem_do_write(pmem, bvec.bv_page,\n 227:\t\t\t\t\t\t\t bvec.bv_offset,\n 228:\t\t\t\t\t\t\t iter.bi_sector,\n 229:\t\t\t\t\t\t\t bvec.bv_len);\n 230:\t\t\t\telse\n 231:\t\t\t\t\trc = pmem_do_read(pmem, bvec.bv_page,\n 232:\t\t\t\t\t\t\t bvec.bv_offset,\n 233:\t\t\t\t\t\t\t iter.bi_sector,\n 234:\t\t\t\t\t\t\t bvec.bv_len);\n 235:\t\t\t\tif (rc) {\n 236:\t\t\t\t\tbio-\u003ebi_status = rc;\n 237:\t\t\t\t\tbreak;\n 238:\t\t\t\t}\n 239:\t\t\t}\n" }
41/2	2026/09/25 11:22	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 49931 output: 38 thoughts: 68 Thoughts: Okay, let's break this down. Decoding the pmem Block Device Operation Right, so `pmem_submit_bio`... that rings a bell. Ah yes, it's the critical `.submit_bio` callback function for the pmem block device, isn't it? The core mechanism to handle block I/O. Now, what's this `pmem_recovery_write` function all about? I need a refresher on how that fits into the picture. Time to dive into the source. Let me quickly jump over to `drivers/nvdimm/pmem.c` and take a look specifically at lines 340-375. That should give me the context I need.
42/2	2026/09/25 11:22	tool	read-file	0m Args: { "File": "drivers/nvdimm/pmem.c", "FirstLine": 340, "LineCount": 40 } Results: { "Contents": " 340:\tstatic size_t pmem_recovery_write(struct dax_device dax_dev, pgoff_t pgoff,\n 341:\t\t\tvoid addr, size_t bytes, struct iov_iter i)\n 342:\t{\n 343:\t\tstruct pmem_device pmem = dax_get_private(dax_dev);\n 344:\t\tsize_t olen, len, off;\n 345:\t\tphys_addr_t pmem_off;\n 346:\t\tstruct device dev = pmem-\u003ebb.dev;\n 347:\t\tlong cleared;\n 348:\t\n 349:\t\toff = offset_in_page(addr);\n 350:\t\tlen = PFN_PHYS(PFN_UP(off + bytes));\n 351:\t\tif (!is_bad_pmem(\u0026pmem-\u003ebb, PFN_PHYS(pgoff) \u003e\u003e SECTOR_SHIFT, len))\n 352:\t\t\treturn _copy_from_iter_flushcache(addr, bytes, i);\n 353:\t\n 354:\t\t/\n 355:\t\t * Not page-aligned range cannot be recovered. This should not\n 356:\t\t * happen unless something else went wrong.\n 357:\t\t */\n 358:\t\tif (off \|\| !PAGE_ALIGNED(bytes)) {\n 359:\t\t\tdev_dbg(dev, \"Found poison, but addr(%p) or bytes(%#zx) not page aligned\\n\",\n 360:\t\t\t\taddr, bytes);\n 361:\t\t\treturn 0;\n 362:\t\t}\n 363:\t\n 364:\t\tpmem_off = PFN_PHYS(pgoff) + pmem-\u003edata_offset;\n 365:\t\tcleared = __pmem_clear_poison(pmem, pmem_off, len);\n 366:\t\tif (cleared \u003e 0 \u0026\u0026 cleared \u003c len) {\n 367:\t\t\tdev_dbg(dev, \"poison cleared only %ld out of %zu bytes\\n\",\n 368:\t\t\t\tcleared, len);\n 369:\t\t\treturn 0;\n 370:\t\t}\n 371:\t\tif (cleared \u003c 0) {\n 372:\t\t\tdev_dbg(dev, \"poison clear failed: %ld\\n\", cleared);\n 373:\t\t\treturn 0;\n 374:\t\t}\n 375:\t\n 376:\t\tolen = _copy_from_iter_flushcache(addr, bytes, i);\n 377:\t\tpmem_clear_bb(pmem, to_sect(pmem, pmem_off), cleared \u003e\u003e SECTOR_SHIFT);\n 378:\t\n 379:\t\treturn olen;\n" }
43/2	2026/09/25 11:22	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 50903 output: 36 thoughts: 16 Thoughts: Okay, here's my summary, tailored for an expert audience, as if I'm thinking these things myself: Tracing the Usage of `pmem_recovery_write` Alright, time to dive in. I need to understand where `pmem_recovery_write` is being used. This function is likely critical to persistent memory recovery, so understanding its call graph is paramount. I'll need to use my usual tools – probably `grep` with some careful filtering to pinpoint the exact locations, or maybe even fire up a source code browser if this project is set up with one. I'll be looking for both direct calls and any indirect usage – perhaps through function pointers or macros. Understanding the context surrounding those references will give me a better understanding of the overall recovery logic. It's important to differentiate between reads and writes, and how the recovery function fits into that picture.
44/2	2026/09/25 11:22	tool	grepper	0m Args: { "Expression": "pmem_recovery_write", "PathPrefix": "drivers/nvdimm/pmem.c" } Results: { "Output": "drivers/nvdimm/pmem.c=318=static long pmem_dax_direct_access(struct dax_device dax_dev,\n--\ndrivers/nvdimm/pmem.c-339- /\ndrivers/nvdimm/pmem.c:340:static size_t pmem_recovery_write(struct dax_device dax_dev, pgoff_t pgoff,\ndrivers/nvdimm/pmem.c-341-\t\tvoid addr, size_t bytes, struct iov_iter *i)\n--\ndrivers/nvdimm/pmem.c=382=static const struct dax_operations pmem_dax_ops = {\n--\ndrivers/nvdimm/pmem.c-384-\t.zero_page_range = pmem_dax_zero_page_range,\ndrivers/nvdimm/pmem.c:385:\t.recovery_write = pmem_recovery_write,\ndrivers/nvdimm/pmem.c-386-};\n" }
45/2	2026/09/25 11:22	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 51409 output: 19 thoughts: 474 Thoughts: Analyzing HWPoison and PMEM Integration Okay, let's dive into the configurations related to `BLK_DEV_PMEM` and, crucially, how `TESTSCFLAG_FALSE` interacts with the `HWPoison` page flag. My initial observation is focused on `include/linux/page-flags.h`, specifically how the `HWPoison` flag is handled based on the presence or absence of `CONFIG_MEMORY_FAILURE`. When `CONFIG_MEMORY_FAILURE` is not defined, we end up using `TESTSCFLAG_FALSE(HWPoison, hwpoison)`. My next thought is about where this comes into play; it's `pmem_mkpage_present` in `pmem.c`, which calls `TestClearPageHWPoison(page)`. So, which configurations actually compile `pmem.c`? This requires a quick check of `drivers/nvdimm/Kconfig`. `CONFIG_BLK_DEV_PMEM` is clearly the key here. It's tristate, and that means it can be built in. It depends on `LIBNVDIMM`, and after going through the dependencies, `LIBNVDIMM` is dependent on the `PHYS_ADDR_T_64BIT`, `HAS_IOMEM`, `BLK_DEV`, and selects `MEMREGION`. Okay, so to thoroughly test both branches of that `#ifdef CONFIG_MEMORY_FAILURE`, I need to consider both scenarios: where it's enabled and where it's disabled. `MEMORY_FAILURE` can be considered in this case, but in particular, I should be looking at `BLK_DEV_PMEM` and `LIBNVDIMM`. Now, the crucial question: can `BLK_DEV_PMEM` be effectively built-in (`=y`)? Given that it's tristate/bool, the answer is yes. I'm also wondering about `CONFIG_MEMORY_FAILURE` itself. Let me just quickly check `mm/Kconfig` to be certain.
46/2	2026/09/25 11:22	tool	grepper	0m Args: { "Expression": "config MEMORY_FAILURE" } Results: { "Output": "mm/Kconfig=757=config ARCH_SUPPORTS_MEMORY_FAILURE\n--\nmm/Kconfig-759-\nmm/Kconfig:760:config MEMORY_FAILURE\nmm/Kconfig-761-\tdepends on MMU\n" }
47/2	2026/09/25 11:22	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 52411 output: 32 thoughts: 17 Thoughts: Okay, here's my interpretation of that thought process, assuming I'm deep in kernel configuration: Navigating the Kernel Configuration Labyrinth Alright, I need to investigate something related to the memory management subsystem. Thinking about where the relevant configuration options reside, `mm/Kconfig` is the likely candidate. That's usually the place to start when digging into memory-related settings. I remember that file is huge, but it's well-structured. Let me zero in on the area around line 760. That feels like a reasonable starting point. Hopefully, what I'm looking for is there or at least leads me to the right section within that Kconfig file. Let's see what that area of the code has to say. Time to start digging!
48/2	2026/09/25 11:22	tool	read-file	0m Args: { "File": "mm/Kconfig", "FirstLine": 757, "LineCount": 20 } Results: { "Contents": " 757:\tconfig ARCH_SUPPORTS_MEMORY_FAILURE\n 758:\t\tbool\n 759:\t\n 760:\tconfig MEMORY_FAILURE\n 761:\t\tdepends on MMU\n 762:\t\tdepends on ARCH_SUPPORTS_MEMORY_FAILURE\n 763:\t\tbool \"Enable recovery from hardware memory errors\"\n 764:\t\tselect INTERVAL_TREE\n 765:\t\tselect MIGRATION\n 766:\t\thelp\n 767:\t\t Enables code to recover from some memory failures on systems\n 768:\t\t with MCA recovery. This allows a system to continue running\n 769:\t\t even when some of its memory has uncorrected errors. This requires\n 770:\t\t special hardware support and typically ECC memory.\n 771:\t\n 772:\tconfig HWPOISON_INJECT\n 773:\t\ttristate \"HWPoison pages injector\"\n 774:\t\tdepends on MEMORY_FAILURE \u0026\u0026 DEBUG_KERNEL \u0026\u0026 PROC_FS\n 775:\t\tselect PROC_PAGE_MONITOR\n 776:\t\n" }
49/2	2026/09/25 11:22	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 52909 output: 236 thoughts: 689 Thoughts: Analysis of Persistent Memory Driver Code for Fuzzing Okay, let's break this down. My initial thought process is centered around the persistent memory (`pmem`) driver within the kernel. I see that `pmem.c` is compiled when `CONFIG_BLK_DEV_PMEM` and `CONFIG_LIBNVDIMM` are enabled. I need to be precise, so I confirm that if `CONFIG_BLK_DEV_PMEM` is directly set to `y`, the `pmem.o` object file will be built into the kernel, which is what I want to see. Next, I'm noting the dependency on `CONFIG_MEMORY_FAILURE`. The new `TESTSCFLAG_FALSE` macro in `include/linux/page-flags.h` is used when it's not set. If it is set, then `TestClearPageHWPoison` is directly called instead. I'm also ensuring I don't miss anything, so I'm checking if `CONFIG_DAX`, `CONFIG_X86_PMEM_LEGACY`, or `CONFIG_VIRTIO_PMEM` have any impact here. `CONFIG_BLK_DEV_PMEM` selects `CONFIG_DAX`, and `CONFIG_LIBNVDIMM` is a prerequisite for `CONFIG_BLK_DEV_PMEM` to be available. Now I'm focusing on key symbols within `pmem.c` to identify potential fuzzing targets. I see specific functions like `pmem_mkpage_present`, `__pmem_clear_poison`, `pmem_clear_poison`, `pmem_recovery_write`, `pmem_do_write`, and `pmem_submit_bio`. My immediate assessment is that these are specific to the PMEM driver and are not ubiquitous kernel functions. That's good, it makes the scope more manageable and less likely to introduce false positives. Let me double-check all angles. The patch in question defines `TESTSCFLAG_FALSE` and refactors `pmem_mkpage_present()` to use `TestClearPageHWPoison(page)` directly. Reachability is clear: it's accessible in virtualized environments like QEMU with virtio-pmem, or on systems with ACPI NFIT or memmap/e820 persistent memory block devices. It checks all of my boxes for fuzzing: it modifies memory management flags and involves reachable driver code. It doesn't fall into any of the negative criteria I have. The relevant configuration options are `LIBNVDIMM` and `BLK_DEV_PMEM`, and those `FocusSymbols` are correct and relevant. Alright, I'm confident in this analysis. Everything checks out. I'll provide this as the final reply with `set-results`.
50/2	2026/09/25 11:22	tool	set-results	0m Args: { "EnableConfigs": [ "LIBNVDIMM", "BLK_DEV_PMEM" ], "FocusSymbols": [ "pmem_mkpage_present", "__pmem_clear_poison", "pmem_clear_poison", "pmem_recovery_write", "pmem_do_write", "pmem_submit_bio" ], "Reasoning": "The patch introduces TESTSCFLAG_FALSE(HWPoison, hwpoison) to core memory management (include/linux/page-flags.h) for !CONFIG_MEMORY_FAILURE builds, and removes a custom wrapper in pmem.h by switching callers in drivers/nvdimm/pmem.c (pmem_mkpage_present) directly to TestClearPageHWPoison. The modified code resides in core mm headers and the PMEM block driver, which is reachable in virtualized environments (QEMU/virtio-pmem, memmap, ACPI NFIT). Refactoring helper abstractions in reachable code paths warrants fuzzing.", "WorthFuzzing": true } Results: { "EnableConfigs": [ "LIBNVDIMM", "BLK_DEV_PMEM" ], "FocusSymbols": [ "pmem_mkpage_present", "__pmem_clear_poison", "pmem_clear_poison", "pmem_recovery_write", "pmem_do_write", "pmem_submit_bio" ], "Reasoning": "The patch introduces TESTSCFLAG_FALSE(HWPoison, hwpoison) to core memory management (include/linux/page-flags.h) for !CONFIG_MEMORY_FAILURE builds, and removes a custom wrapper in pmem.h by switching callers in drivers/nvdimm/pmem.c (pmem_mkpage_present) directly to TestClearPageHWPoison. The modified code resides in core mm headers and the PMEM block driver, which is reachable in virtualized environments (QEMU/virtio-pmem, memmap, ACPI NFIT). Refactoring helper abstractions in reachable code paths warrants fuzzing.", "WorthFuzzing": true }
51/1	2026/09/25 11:22	action	If	0m Args: { "WorthFuzzing": true } Results: null
52/2	2026/09/25 11:22	agent	kmsan-evaluator	0m Model: core Args: null Results: { "KMSANReasoning": "The patch is a cleanup/refactoring that removes a driver-specific wrapper (`test_and_clear_pmem_poison`) in `drivers/nvdimm/pmem.h` and instead provides the standard `TESTSCFLAG_FALSE(HWPoison, hwpoison)` fallback in `include/linux/page-flags.h` for when `CONFIG_MEMORY_FAILURE` is disabled. This allows `drivers/nvdimm/pmem.c` to call `TestClearPageHWPoison(page)` directly.\n\nThis change does not allocate or copy any memory, does not modify any data structures passed to userspace or across security boundaries, and does not alter variable initialization or introduce uninitialized memory reads. Consequently, there are no uninitialized memory risks or info-leak hazards that would require KMSAN detection. Standard test/sanitizer coverage (e.g. KASAN) is sufficient.", "NeedsKMSAN": false } Instruction: You are an expert Linux kernel security engineer specializing in kernel memory error detectors (KASAN and KMSAN). Your job is to review the provided patch series and determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer) fuzzing session in addition to standard KASAN fuzzing. CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN: - Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable a comprehensive suite of debugging tools and sanitizers, including KASAN (out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP (locking bugs and deadlocks), UB-sanitizers, and memory corruption checks. - KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap, or page allocations) and kernel-to-user memory info-leaks. Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN, LOCKDEP, OR OTHER STANDARD BUG DETECTORS. A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks that are detected ONLY by KMSAN. Look holistically at the patch series and surrounding code. Even if no direct uninitialized field accesses or new buffer allocations are added in the diff itself, a patch may alter control flow, bounds checking, or data length calculations in ways that change how the rest of the code operates on existing buffers (e.g. allowing uninitialized stack/heap memory to be read, copied to user space, or used in control flow). Do not hesitate to use your code access tools to inspect the surrounding code, called functions, and callers. Set NeedsKMSAN=true ONLY IF the patch introduces or modifies: 1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb attributes, ioctl output arguments, socket options, or BPF buffers) where fields or structure padding might not be fully initialized/zeroed. 2. Conditional logic or branching that depends on potentially uninitialized variables or struct fields. 3. Allocation or initialization of complex data structures where uninitialized fields could be read later in reachable code paths. 4. Bounds checks, lengths, or logic in a way that allows surrounding code to access uninitialized bytes of existing buffers. Set NeedsKMSAN=false IF: - The code changes primarily risk out-of-bounds access, array overflows, NULL pointer dereferences, locking deadlocks, or use-after-free bugs (these are already caught by KASAN, LOCKDEP, or standard bug detectors). - All stack/heap structures touched or introduced by the patch are fully zeroed or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied. - The patch does not introduce any risk of uninitialized memory usage or info-leaks. Use your code access tools to inspect the surrounding code if necessary, then provide detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch. 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: Target architecture: amd64 For your convenience, here is the diff of the changes: commit 3b682ae789c01f7ba36ce00392c9724354d94fc6 Author: syz-cluster <triage@syzkaller.com> Date: Fri Sep 25 11:20:43 2026 +0000 syz-cluster: applied patch under review diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 30a51c365ce8b..5fb86595e8bd7 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -80,7 +80,7 @@ static void pmem_mkpage_present(struct pmem_device pmem, phys_addr_t offset, here since we're in the driver I/O path and * outstanding I/O requests pin the dev_pagemap. / - if (test_and_clear_pmem_poison(page)) + if (TestClearPageHWPoison(page)) clear_mce_nospec(pfn); } } diff --git a/drivers/nvdimm/pmem.h b/drivers/nvdimm/pmem.h index a48509f901968..76870505dd797 100644 --- a/drivers/nvdimm/pmem.h +++ b/drivers/nvdimm/pmem.h @@ -1,7 +1,6 @@ / SPDX-License-Identifier: GPL-2.0 / #ifndef __NVDIMM_PMEM_H__ #define __NVDIMM_PMEM_H__ -#include <linux/page-flags.h> #include <linux/badblocks.h> #include <linux/memremap.h> #include <linux/types.h> @@ -31,15 +30,4 @@ long __pmem_direct_access(struct pmem_device pmem, pgoff_t pgoff, long nr_pages, enum dax_access_mode mode, void *kaddr, unsigned long pfn); -#ifdef CONFIG_MEMORY_FAILURE -static inline bool test_and_clear_pmem_poison(struct page page) -{ - return TestClearPageHWPoison(page); -} -#else -static inline bool test_and_clear_pmem_poison(struct page page) -{ - return false; -} -#endif #endif /* __NVDIMM_PMEM_H__ */ diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index ae2ebaed6d4d9..3dc79c0c5adf0 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -655,6 +655,7 @@ TESTSCFLAG(HWPoison, hwpoison, PF_ANY) #define __PG_HWPOISON (1UL << PG_hwpoison) #else PAGEFLAG_FALSE(HWPoison, hwpoison) +TESTSCFLAG_FALSE(HWPoison, hwpoison) #define __PG_HWPOISON 0 #endif
53/3	2026/09/25 11:22	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 2627 output: 34 thoughts: 995 Thoughts: Analyzing the NVDIMM PMEM Patch Okay, let's break this down. My initial assessment is that this is a fairly straightforward cleanup and optimization patch for the NVDIMM persistent memory driver. Specifically, it's about how the driver handles hardware-detected memory errors, or "poisoned" pages. I see they've updated `include/linux/page-flags.h` – specifically around the definition of the `HWPoison` page flag. It looks like they're now using the standard `TESTSCFLAG_FALSE` macro, which is the correct approach. In `drivers/nvdimm/pmem.h`, the custom helper function `test_and_clear_pmem_poison` defined in earlier versions is now gone. The core of the change lies in how the driver interacts with the `HWPoison` flag. Previously, there was a custom function defined within the PMEM driver. Now, the driver directly calls the kernel's `TestClearPageHWPoison` function. This indicates a move toward using the kernel's standardized interface for this functionality. Specifically, when `CONFIG_MEMORY_FAILURE` is not enabled, the custom helper was defined to return false, now the change is being done within the kernel's `page-flags.h`. The net effect is that they've replaced a driver-specific abstraction with the standard kernel abstraction, improving code consistency and maintainability. It simplifies the code in `pmem.c`, making it easier to read and understand. This is a good practice because it avoids code duplication and ensures that the driver integrates with the core memory management subsystem correctly. It's likely an effort to modernize the code, potentially removing a now-unnecessary layer of abstraction. I'd want to quickly review the `TestClearPageHWPoison` definition in the relevant architecture-specific code to make sure there are no subtle architecture-specific details that need to be considered, but overall, it looks like a clean and sensible change.
54/3	2026/09/25 11:22	tool	grepper	0m Args: { "Expression": "TESTSCFLAG_FALSE", "PathPrefix": "include/linux/page-flags.h" } Results: { "Output": "include/linux/page-flags.h=537=static inline int TestClearPage##uname(struct page *page) { return 0; }\n--\ninclude/linux/page-flags.h-541-\ninclude/linux/page-flags.h:542:#define TESTSCFLAG_FALSE(uname, lname)\t\t\t\t\t\\\ninclude/linux/page-flags.h-543-\tTESTSETFLAG_FALSE(uname, lname) TESTCLEARFLAG_FALSE(uname, lname)\n--\ninclude/linux/page-flags.h=657=PAGEFLAG_FALSE(HWPoison, hwpoison)\ninclude/linux/page-flags.h:658:TESTSCFLAG_FALSE(HWPoison, hwpoison)\ninclude/linux/page-flags.h-659-#define __PG_HWPOISON 0\n" }
55/3	2026/09/25 11:22	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 4289 output: 217 thoughts: 631 Thoughts: Analyzing a Refactoring Patch for Potential Memory Safety Issues Okay, let's break this down. I'm looking at a patch that essentially cleans up some code in the `drivers/nvdimm/pmem.c` file. Specifically, it's about removing a redundant wrapper function, `test_and_clear_pmem_poison()`, and directly calling `TestClearPageHWPoison(page)` now. The key here is the conditional compilation based on `CONFIG_MEMORY_FAILURE`. When this feature is enabled, `TestClearPageHWPoison` gets its definition through the `TESTSCFLAG` macro, but when disabled, it uses `TESTSCFLAG_FALSE`, which ultimately defines `TestClearPageHWPoison` to simply return 0. My immediate concern, as always, is memory safety. Could this change introduce or expose uninitialized memory issues? I need to meticulously go through the logic. First, I need to consider if this change affects any of the below: 1. Kernel structures sent to userspace: Nope. The code in question operates on a `struct page`, which is internal to the kernel, so this is not a concern. 2. Conditional logic based on potentially uninitialized variables: No. `TestClearPageHWPoison(page)` either works on the `page->flags` in an atomic manner or simply returns 0 in the `!CONFIG_MEMORY_FAILURE` case. 3. Allocation or initialization of complex data structures: Not involved. The patch works on an existing `struct page`. 4. Bounds checks: No. This doesn't seem to affect any bounds checks or introduce any way to leak uninitialized data. So, the existing `page` structure is passed to the function, and it is either modified or just returns 0, depending on the configuration. There are no allocations or direct handling of user space buffers here. Therefore, the `NeedsKMSAN` flag is `false`. There are no new risks related to uninitialized memory introduced, nor is anything leaked to user space. This is a refactoring patch that simplifies the code while maintaining its existing behavior regarding memory safety. Let's make sure that's clearly stated in the reasoning.
56/3	2026/09/25 11:23	tool	set-results	0m Args: { "KMSANReasoning": "The patch is a cleanup/refactoring that removes a driver-specific wrapper (`test_and_clear_pmem_poison`) in `drivers/nvdimm/pmem.h` and instead provides the standard `TESTSCFLAG_FALSE(HWPoison, hwpoison)` fallback in `include/linux/page-flags.h` for when `CONFIG_MEMORY_FAILURE` is disabled. This allows `drivers/nvdimm/pmem.c` to call `TestClearPageHWPoison(page)` directly.\n\nThis change does not allocate or copy any memory, does not modify any data structures passed to userspace or across security boundaries, and does not alter variable initialization or introduce uninitialized memory reads. Consequently, there are no uninitialized memory risks or info-leak hazards that would require KMSAN detection. Standard test/sanitizer coverage (e.g. KASAN) is sufficient.", "NeedsKMSAN": false } Results: { "KMSANReasoning": "The patch is a cleanup/refactoring that removes a driver-specific wrapper (`test_and_clear_pmem_poison`) in `drivers/nvdimm/pmem.h` and instead provides the standard `TESTSCFLAG_FALSE(HWPoison, hwpoison)` fallback in `include/linux/page-flags.h` for when `CONFIG_MEMORY_FAILURE` is disabled. This allows `drivers/nvdimm/pmem.c` to call `TestClearPageHWPoison(page)` directly.\n\nThis change does not allocate or copy any memory, does not modify any data structures passed to userspace or across security boundaries, and does not alter variable initialization or introduce uninitialized memory reads. Consequently, there are no uninitialized memory risks or info-leak hazards that would require KMSAN detection. Standard test/sanitizer coverage (e.g. KASAN) is sufficient.", "NeedsKMSAN": false }

LLM Calls Summary:
Total Calls	Total Tokens	Avg Tokens	Total Duration (Seconds)	Avg Duration (Seconds)

Tool Calls Summary:
Total Calls	Total Duration (Seconds)	Avg Duration (Seconds)