AI Trajectory

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies userspace selftests in tools/testing/selftests/mm/ and does not make any functional changes to the kernel code itself.",
  "WorthFuzzing": false
}

null

{
  "PatchDiff": "commit 3ca28008c36e47f9f974943ce4f85bf5087cbf17\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Mon Jul 27 20:47:03 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c\nindex 0c627ea89ff7b2..c1b8920e293424 100644\n--- a/tools/testing/selftests/mm/cow.c\n+++ b/tools/testing/selftests/mm/cow.c\n@@ -1718,8 +1718,13 @@ static void run_with_tmpfile(non_anon_test_fn fn, const char *desc)\n \n \t/* File consists of a single page filled with zeroes. */\n \tif (fallocate(fd, 0, 0, pagesize)) {\n-\t\tksft_perror(\"fallocate() failed\");\n-\t\tlog_test_result(KSFT_FAIL);\n+\t\tif (errno == EOPNOTSUPP) {\n+\t\t\tksft_print_msg(\"fallocate() not supported by filesystem\\n\");\n+\t\t\tlog_test_result(KSFT_SKIP);\n+\t\t} else {\n+\t\t\tksft_perror(\"fallocate() failed\");\n+\t\t\tlog_test_result(KSFT_FAIL);\n+\t\t}\n \t\tgoto close;\n \t}\n \ndiff --git a/tools/testing/selftests/mm/guard-regions.c b/tools/testing/selftests/mm/guard-regions.c\nindex b21df3040b1c7c..5c8ec3ca75d7d2 100644\n--- a/tools/testing/selftests/mm/guard-regions.c\n+++ b/tools/testing/selftests/mm/guard-regions.c\n@@ -1912,7 +1912,7 @@ TEST_F(guard_regions, hole_punch)\n {\n \tconst unsigned long page_size = self-\u003epage_size;\n \tchar *ptr;\n-\tint i;\n+\tint i, ret;\n \n \tif (variant-\u003ebacking == ANON_BACKED)\n \t\tSKIP(return, \"Truncation test specific to file-backed\");\n@@ -1944,8 +1944,12 @@ TEST_F(guard_regions, hole_punch)\n \t}\n \n \t/* Now hole punch the guarded region. */\n-\tASSERT_EQ(madvise(\u0026ptr[3 * page_size], 4 * page_size,\n-\t\t\t  MADV_REMOVE), 0);\n+\tret = madvise(\u0026ptr[3 * page_size], 4 * page_size, MADV_REMOVE);\n+\tif (ret == -1 \u0026\u0026 errno == EOPNOTSUPP) {\n+\t\tASSERT_EQ(munmap(ptr, 10 * page_size), 0);\n+\t\tSKIP(return, \"MADV_REMOVE not supported by filesystem\");\n+\t}\n+\tASSERT_EQ(ret, 0);\n \n \t/* Ensure guard regions remain. */\n \tfor (i = 0; i \u003c 10; i++) {\ndiff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c\nindex 10e8dedcb087dc..54e888eb48bbcb 100644\n--- a/tools/testing/selftests/mm/khugepaged.c\n+++ b/tools/testing/selftests/mm/khugepaged.c\n@@ -100,6 +100,28 @@ static void skip(const char *msg)\n \texit_status = KSFT_SKIP;\n }\n \n+static bool is_swap_enabled(void)\n+{\n+\tchar buf[MAX_LINE_LENGTH];\n+\tFILE *file;\n+\tbool enabled = false;\n+\n+\tfile = fopen(\"/proc/swaps\", \"r\");\n+\tif (!file)\n+\t\treturn false;\n+\n+\tif (!fgets(buf, sizeof(buf), file))\n+\t\tgoto out;\n+\n+\t/* Check for first active swap entry. */\n+\tif (fgets(buf, sizeof(buf), file))\n+\t\tenabled = true;\n+\n+out:\n+\tfclose(file);\n+\treturn enabled;\n+}\n+\n static void save_settings(void)\n {\n \tksft_print_msg(\"Save THP and khugepaged settings...\");\n@@ -734,10 +756,16 @@ static void collapse_swapin_single_pte(struct collapse_context *c, struct mem_op\n {\n \tvoid *p;\n \n+\tksft_print_msg(\"Swapout one page...\");\n+\tif (!is_swap_enabled()) {\n+\t\tskip(\"No active swap\");\n+\t\tksft_test_result_report(exit_status, \"%s\\n\", __func__);\n+\t\treturn;\n+\t}\n+\n \tp = ops-\u003esetup_area(1);\n \tops-\u003efault(p, 0, hpage_pmd_size);\n \n-\tksft_print_msg(\"Swapout one page...\");\n \tif (madvise(p, page_size, MADV_PAGEOUT))\n \t\tksft_exit_fail_perror(\"madvise(MADV_PAGEOUT)\");\n \tif (check_swap(p, page_size)) {\n@@ -760,10 +788,16 @@ static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *o\n \tint max_ptes_swap = thp_read_num(\"khugepaged/max_ptes_swap\");\n \tvoid *p;\n \n+\tksft_print_msg(\"Swapout %d of %d pages...\", max_ptes_swap + 1, hpage_pmd_nr);\n+\tif (!is_swap_enabled()) {\n+\t\tskip(\"No active swap\");\n+\t\tksft_test_result_report(exit_status, \"%s\\n\", __func__);\n+\t\treturn;\n+\t}\n+\n \tp = ops-\u003esetup_area(1);\n \tops-\u003efault(p, 0, hpage_pmd_size);\n \n-\tksft_print_msg(\"Swapout %d of %d pages...\", max_ptes_swap + 1, hpage_pmd_nr);\n \tif (madvise(p, (max_ptes_swap + 1) * page_size, MADV_PAGEOUT))\n \t\tksft_exit_fail_perror(\"madvise(MADV_PAGEOUT)\");\n \tif (check_swap(p, (max_ptes_swap + 1) * page_size)) {\ndiff --git a/tools/testing/selftests/mm/memory-failure.c b/tools/testing/selftests/mm/memory-failure.c\nindex 032ed952057c62..5d00aab31f9b55 100644\n--- a/tools/testing/selftests/mm/memory-failure.c\n+++ b/tools/testing/selftests/mm/memory-failure.c\n@@ -283,8 +283,10 @@ TEST_F(memory_failure, clean_pagecache)\n \tif (fd \u003c 0)\n \t\tSKIP(return, \"failed to open test file.\\n\");\n \tfs_type = get_fs_type(fd);\n-\tif (!fs_type || fs_type == TMPFS_MAGIC)\n+\tif (!fs_type || fs_type == TMPFS_MAGIC) {\n+\t\tclose(fd);\n \t\tSKIP(return, \"unsupported filesystem :%x\\n\", fs_type);\n+\t}\n \n \taddr = mmap(0, self-\u003epage_size, PROT_READ | PROT_WRITE,\n \t\t    MAP_SHARED, fd, 0);\n@@ -325,8 +327,16 @@ TEST_F(memory_failure, dirty_pagecache)\n \tif (fd \u003c 0)\n \t\tSKIP(return, \"failed to open test file.\\n\");\n \tfs_type = get_fs_type(fd);\n-\tif (!fs_type || fs_type == TMPFS_MAGIC)\n+\t/*\n+\t * MADV_HARD poisoning of dirty page-cache data records an expected\n+\t * -EIO in the file mapping. NFS reports this error on close(), so\n+\t * skip this variant.\n+\t */\n+\tif (!fs_type || fs_type == TMPFS_MAGIC ||\n+\t    (fs_type == NFS_SUPER_MAGIC \u0026\u0026 variant-\u003etype == MADV_HARD)) {\n+\t\tclose(fd);\n \t\tSKIP(return, \"unsupported filesystem :%x\\n\", fs_type);\n+\t}\n \n \taddr = mmap(0, self-\u003epage_size, PROT_READ | PROT_WRITE,\n \t\t    MAP_SHARED, fd, 0);\ndiff --git a/tools/testing/selftests/mm/migration.c b/tools/testing/selftests/mm/migration.c\nindex 29f7492453d439..f19d53c6957644 100644\n--- a/tools/testing/selftests/mm/migration.c\n+++ b/tools/testing/selftests/mm/migration.c\n@@ -7,7 +7,7 @@\n #include \"kselftest_harness.h\"\n #include \"hugepage_settings.h\"\n \n-#include \u003cstrings.h\u003e\n+#include \u003cstring.h\u003e\n #include \u003cpthread.h\u003e\n #include \u003cnuma.h\u003e\n #include \u003cnumaif.h\u003e\n@@ -20,7 +20,6 @@\n \n #define TWOMEG\t\t(2\u003c\u003c20)\n #define RUNTIME\t\t(20)\n-#define MAX_RETRIES\t100\n #define ALIGN(x, a)\t(((x) + (a - 1)) \u0026 (~((a) - 1)))\n \n HUGETLB_SETUP_DEFAULT_PAGES(1)\n@@ -110,7 +109,7 @@ int migrate(uint64_t *ptr, int n1, int n2)\n \tint ret, tmp;\n \tint status = 0;\n \tstruct timespec ts1, ts2;\n-\tint failures = 0;\n+\tint success = 0;\n \n \tif (clock_gettime(CLOCK_MONOTONIC, \u0026ts1))\n \t\treturn -1;\n@@ -119,29 +118,33 @@ int migrate(uint64_t *ptr, int n1, int n2)\n \t\tif (clock_gettime(CLOCK_MONOTONIC, \u0026ts2))\n \t\t\treturn -1;\n \n-\t\tif (ts2.tv_sec - ts1.tv_sec \u003e= RUNTIME)\n-\t\t\treturn 0;\n+\t\tif (ts2.tv_sec - ts1.tv_sec \u003e= RUNTIME) {\n+\t\t\t/* Reaching both targets verifies a cross-node move. */\n+\t\t\tif (success \u003e= 2)\n+\t\t\t\treturn 0;\n+\t\t\telse\n+\t\t\t\treturn -2;\n+\t\t}\n \n \t\tret = move_pages(0, 1, (void **) \u0026ptr, \u0026n2, \u0026status,\n \t\t\t\tMPOL_MF_MOVE_ALL);\n-\t\tif (ret) {\n-\t\t\tif (ret \u003e 0) {\n-\t\t\t\t/* Migration is best effort; try again */\n-\t\t\t\tif (++failures \u003c MAX_RETRIES)\n-\t\t\t\t\tcontinue;\n-\t\t\t\tprintf(\"Didn't migrate %d pages\\n\", ret);\n-\t\t\t}\n-\t\t\telse\n-\t\t\t\tperror(\"Couldn't migrate pages\");\n+\t\tif (ret \u003c 0) {\n+\t\t\tperror(\"Couldn't migrate pages\");\n+\t\t\treturn ret;\n+\t\t}\n+\t\t/* Migration is best effort. Try again */\n+\t\tif (ret \u003e 0 || status \u003c 0)\n+\t\t\tcontinue;\n+\t\tif (status != n2) {\n+\t\t\tprintf(\"Page is on node %d instead of target node %d\\n\",\n+\t\t\t       status, n2);\n \t\t\treturn -2;\n \t\t}\n-\t\tfailures = 0;\n+\t\tsuccess++;\n \t\ttmp = n2;\n \t\tn2 = n1;\n \t\tn1 = tmp;\n \t}\n-\n-\treturn 0;\n }\n \n void *access_mem(void *ptr)\n"
}

best-expensive

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies userspace selftests in tools/testing/selftests/mm/ and does not make any functional changes to the kernel code itself.",
  "WorthFuzzing": false
}

You are an expert Linux kernel maintainer.
Your job is to review a provided patch series and determine
if it makes functional changes to the kernel that should be fuzzed.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively
use your code access tools to examine the actual source code and confirm any assumptions.

Return WorthFuzzing=false if the patch only contains:
- Modifications to Documentation/, Kconfig files, or code comments.
- Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints.
- Changes to numeric constants or macros that do not functionally alter execution flow.
- Code paths that are impossible to reach in virtualized environments like GCE or QEMU,
  even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim).
- Code in vendor-specific PCIe switch, SmartNIC, or GPU drivers (e.g., mlxsw, pds_core, qed,
  ionic, amdgpu) that require physical PCIe hardware cards not emulated in standard QEMU.
- Driver .remove, .shutdown, or pci_unregister_driver teardown callbacks (e.g., igb_remove)
  that are executed only during PCI hot-unplug or sysfs driver unbind operations.

If it modifies reachable core kernel logic, drivers, or architectures, use your code search
tools to verify the code can be executed, then return WorthFuzzing=true.

When returning WorthFuzzing=true, you MUST ALSO:
1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols.
   Avoid listing generic hot-path functions to prevent skewed test distributions.
   Prefer non-static, non-inlined API entrypoint functions over internal static helper functions
   (which are inlined by the compiler and do not have distinct symbol addresses).
2. Identify any specific CONFIG_ options required to properly test this new/modified feature.
   Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions.
   Also check "depends on" lines in Kconfig to include any non-standard parent subsystem configs
   needed for Kbuild to compile the code statically into vmlinux. List them in the EnableConfigs
   output array, and DO NOT add a 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4").
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

For your convenience, here is the diff of the changes:
commit 3ca28008c36e47f9f974943ce4f85bf5087cbf17
Author: syz-cluster <triage@syzkaller.com>
Date:   Mon Jul 27 20:47:03 2026 +0000

    syz-cluster: applied patch under review

diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
index 0c627ea89ff7b2..c1b8920e293424 100644
--- a/tools/testing/selftests/mm/cow.c
+++ b/tools/testing/selftests/mm/cow.c
@@ -1718,8 +1718,13 @@ static void run_with_tmpfile(non_anon_test_fn fn, const char *desc)
 
 	/* File consists of a single page filled with zeroes. */
 	if (fallocate(fd, 0, 0, pagesize)) {
-		ksft_perror("fallocate() failed");
-		log_test_result(KSFT_FAIL);
+		if (errno == EOPNOTSUPP) {
+			ksft_print_msg("fallocate() not supported by filesystem\n");
+			log_test_result(KSFT_SKIP);
+		} else {
+			ksft_perror("fallocate() failed");
+			log_test_result(KSFT_FAIL);
+		}
 		goto close;
 	}
 
diff --git a/tools/testing/selftests/mm/guard-regions.c b/tools/testing/selftests/mm/guard-regions.c
index b21df3040b1c7c..5c8ec3ca75d7d2 100644
--- a/tools/testing/selftests/mm/guard-regions.c
+++ b/tools/testing/selftests/mm/guard-regions.c
@@ -1912,7 +1912,7 @@ TEST_F(guard_regions, hole_punch)
 {
 	const unsigned long page_size = self->page_size;
 	char *ptr;
-	int i;
+	int i, ret;
 
 	if (variant->backing == ANON_BACKED)
 		SKIP(return, "Truncation test specific to file-backed");
@@ -1944,8 +1944,12 @@ TEST_F(guard_regions, hole_punch)
 	}
 
 	/* Now hole punch the guarded region. */
-	ASSERT_EQ(madvise(&ptr[3 * page_size], 4 * page_size,
-			  MADV_REMOVE), 0);
+	ret = madvise(&ptr[3 * page_size], 4 * page_size, MADV_REMOVE);
+	if (ret == -1 && errno == EOPNOTSUPP) {
+		ASSERT_EQ(munmap(ptr, 10 * page_size), 0);
+		SKIP(return, "MADV_REMOVE not supported by filesystem");
+	}
+	ASSERT_EQ(ret, 0);
 
 	/* Ensure guard regions remain. */
 	for (i = 0; i < 10; i++) {
diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c
index 10e8dedcb087dc..54e888eb48bbcb 100644
--- a/tools/testing/selftests/mm/khugepaged.c
+++ b/tools/testing/selftests/mm/khugepaged.c
@@ -100,6 +100,28 @@ static void skip(const char *msg)
 	exit_status = KSFT_SKIP;
 }
 
+static bool is_swap_enabled(void)
+{
+	char buf[MAX_LINE_LENGTH];
+	FILE *file;
+	bool enabled = false;
+
+	file = fopen("/proc/swaps", "r");
+	if (!file)
+		return false;
+
+	if (!fgets(buf, sizeof(buf), file))
+		goto out;
+
+	/* Check for first active swap entry. */
+	if (fgets(buf, sizeof(buf), file))
+		enabled = true;
+
+out:
+	fclose(file);
+	return enabled;
+}
+
 static void save_settings(void)
 {
 	ksft_print_msg("Save THP and khugepaged settings...");
@@ -734,10 +756,16 @@ static void collapse_swapin_single_pte(struct collapse_context *c, struct mem_op
 {
 	void *p;
 
+	ksft_print_msg("Swapout one page...");
+	if (!is_swap_enabled()) {
+		skip("No active swap");
+		ksft_test_result_report(exit_status, "%s\n", __func__);
+		return;
+	}
+
 	p = ops->setup_area(1);
 	ops->fault(p, 0, hpage_pmd_size);
 
-	ksft_print_msg("Swapout one page...");
 	if (madvise(p, page_size, MADV_PAGEOUT))
 		ksft_exit_fail_perror("madvise(MADV_PAGEOUT)");
 	if (check_swap(p, page_size)) {
@@ -760,10 +788,16 @@ static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *o
 	int max_ptes_swap = thp_read_num("khugepaged/max_ptes_swap");
 	void *p;
 
+	ksft_print_msg("Swapout %d of %d pages...", max_ptes_swap + 1, hpage_pmd_nr);
+	if (!is_swap_enabled()) {
+		skip("No active swap");
+		ksft_test_result_report(exit_status, "%s\n", __func__);
+		return;
+	}
+
 	p = ops->setup_area(1);
 	ops->fault(p, 0, hpage_pmd_size);
 
-	ksft_print_msg("Swapout %d of %d pages...", max_ptes_swap + 1, hpage_pmd_nr);
 	if (madvise(p, (max_ptes_swap + 1) * page_size, MADV_PAGEOUT))
 		ksft_exit_fail_perror("madvise(MADV_PAGEOUT)");
 	if (check_swap(p, (max_ptes_swap + 1) * page_size)) {
diff --git a/tools/testing/selftests/mm/memory-failure.c b/tools/testing/selftests/mm/memory-failure.c
index 032ed952057c62..5d00aab31f9b55 100644
--- a/tools/testing/selftests/mm/memory-failure.c
+++ b/tools/testing/selftests/mm/memory-failure.c
@@ -283,8 +283,10 @@ TEST_F(memory_failure, clean_pagecache)
 	if (fd < 0)
 		SKIP(return, "failed to open test file.\n");
 	fs_type = get_fs_type(fd);
-	if (!fs_type || fs_type == TMPFS_MAGIC)
+	if (!fs_type || fs_type == TMPFS_MAGIC) {
+		close(fd);
 		SKIP(return, "unsupported filesystem :%x\n", fs_type);
+	}
 
 	addr = mmap(0, self->page_size, PROT_READ | PROT_WRITE,
 		    MAP_SHARED, fd, 0);
@@ -325,8 +327,16 @@ TEST_F(memory_failure, dirty_pagecache)
 	if (fd < 0)
 		SKIP(return, "failed to open test file.\n");
 	fs_type = get_fs_type(fd);
-	if (!fs_type || fs_type == TMPFS_MAGIC)
+	/*
+	 * MADV_HARD poisoning of dirty page-cache data records an expected
+	 * -EIO in the file mapping. NFS reports this error on close(), so
+	 * skip this variant.
+	 */
+	if (!fs_type || fs_type == TMPFS_MAGIC ||
+	    (fs_type == NFS_SUPER_MAGIC && variant->type == MADV_HARD)) {
+		close(fd);
 		SKIP(return, "unsupported filesystem :%x\n", fs_type);
+	}
 
 	addr = mmap(0, self->page_size, PROT_READ | PROT_WRITE,
 		    MAP_SHARED, fd, 0);
diff --git a/tools/testing/selftests/mm/migration.c b/tools/testing/selftests/mm/migration.c
index 29f7492453d439..f19d53c6957644 100644
--- a/tools/testing/selftests/mm/migration.c
+++ b/tools/testing/selftests/mm/migration.c
@@ -7,7 +7,7 @@
 #include "kselftest_harness.h"
 #include "hugepage_settings.h"
 
-#include <strings.h>
+#include <string.h>
 #include <pthread.h>
 #include <numa.h>
 #include <numaif.h>
@@ -20,7 +20,6 @@
 
 #define TWOMEG		(2<<20)
 #define RUNTIME		(20)
-#define MAX_RETRIES	100
 #define ALIGN(x, a)	(((x) + (a - 1)) & (~((a) - 1)))
 
 HUGETLB_SETUP_DEFAULT_PAGES(1)
@@ -110,7 +109,7 @@ int migrate(uint64_t *ptr, int n1, int n2)
 	int ret, tmp;
 	int status = 0;
 	struct timespec ts1, ts2;
-	int failures = 0;
+	int success = 0;
 
 	if (clock_gettime(CLOCK_MONOTONIC, &ts1))
 		return -1;
@@ -119,29 +118,33 @@ int migrate(uint64_t *ptr, int n1, int n2)
 		if (clock_gettime(CLOCK_MONOTONIC, &ts2))
 			return -1;
 
-		if (ts2.tv_sec - ts1.tv_sec >= RUNTIME)
-			return 0;
+		if (ts2.tv_sec - ts1.tv_sec >= RUNTIME) {
+			/* Reaching both targets verifies a cross-node move. */
+			if (success >= 2)
+				return 0;
+			else
+				return -2;
+		}
 
 		ret = move_pages(0, 1, (void **) &ptr, &n2, &status,
 				MPOL_MF_MOVE_ALL);
-		if (ret) {
-			if (ret > 0) {
-				/* Migration is best effort; try again */
-				if (++failures < MAX_RETRIES)
-					continue;
-				printf("Didn't migrate %d pages\n", ret);
-			}
-			else
-				perror("Couldn't migrate pages");
+		if (ret < 0) {
+			perror("Couldn't migrate pages");
+			return ret;
+		}
+		/* Migration is best effort. Try again */
+		if (ret > 0 || status < 0)
+			continue;
+		if (status != n2) {
+			printf("Page is on node %d instead of target node %d\n",
+			       status, n2);
 			return -2;
 		}
-		failures = 0;
+		success++;
 		tmp = n2;
 		n2 = n1;
 		n1 = tmp;
 	}
-
-	return 0;
 }
 
 void *access_mem(void *ptr)

gemini-3.1-pro-preview

null

null

							input: 4890
							output: 64
							thoughts: 714
						

**WorthFuzzing Assessment: A Selftest-Centric View**

Okay, so I've got this patch series that's touching a handful of files within `tools/testing/selftests/mm/`.  The files are listed: `cow.c`, `guard-regions.c`, `khugepaged.c`, `memory-failure.c`, and `migration.c`. Straight away, I'm thinking, these are all selftests. They're userspace tools designed to exercise kernel functionality.

Now, the instructions are quite clear. If the patch contains *only* modifications to things like documentation, Kconfig files, comments, or purely decorative logging, or changes to non-functional constants, or unreachable code paths in virtualized environments, or specific driver tear-down functions, then `WorthFuzzing=false`. Then it says to confirm whether "reachable core kernel logic, drivers, or architectures" are modified, and if so, search for it using code search tools, and return `WorthFuzzing=true`.

My immediate reaction is, hold on a second… these are *selftests*. They aren't kernel code. They're just tests. So, they don't modify kernel logic, drivers, or architectures. The files are within the `tools/testing/selftests/mm/` directory.

The question then becomes, do I *always* say `WorthFuzzing=false` for selftests? It does seem that way. They are userspace programs to test the kernel, but the patch isn't changing the kernel itself. Fuzzing the kernel based on selftest changes doesn't make much sense. So it's probably better to focus on actual kernel code.

Just to be absolutely sure, let's take a quick look at the file list one more time: `cow.c`, `guard-regions.c`, `khugepaged.c`, `memory-failure.c`, and `migration.c`. All those files are in `tools/testing/selftests/mm/`. Since the changes are all in userspace tests and don't touch core kernel logic, the conclusion is clear: `WorthFuzzing=false`. This patch is solely concerned with testing and not kernel implementation.

{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies userspace selftests in tools/testing/selftests/mm/ and does not make any functional changes to the kernel code itself.",
  "WorthFuzzing": false
}

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies userspace selftests in tools/testing/selftests/mm/ and does not make any functional changes to the kernel code itself.",
  "WorthFuzzing": false
}