tools/lib/mm: move hugepage_settings out of selftests

Move hugepage_settings.[ch] from tools/testing/selftests/mm/ to
tools/lib/mm/ so the THP and HugeTLB helpers can be shared more easily
between selftests and other tools.

Keep the helpers exposed to mm selftests through vm_util.h where possible,
and use direct <mm/hugepage_settings.h> includes for files that do not
include vm_util.h.  Adjust the selftests/mm build to compile the moved
implementation from its new location.

Remove the remaining kselftest dependency by including file_utils.h
directly and using EXIT_FAILURE in the signal handler.

Link: https://lore.kernel.org/20260918112234.195857-4-sarthak.sharma@arm.com
Signed-off-by: Sarthak Sharma <sarthak.sharma@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Tested-by: Muhammad Usama Anjum <usama.anjum@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>

tools/lib/mm/hugepage_settings.c

@@ -10,11 +10,16 @@
 #include <unistd.h>
 #include <errno.h>
 
-#include "vm_util.h"
+#include "file_utils.h"
 #include "hugepage_settings.h"
 
 #define THP_SYSFS "/sys/kernel/mm/transparent_hugepage/"
 #define MAX_SETTINGS_DEPTH 4
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+#endif
+
 static struct thp_settings settings_stack[MAX_SETTINGS_DEPTH];
 static int settings_index;
 static struct thp_settings saved_settings;
@@ -655,8 +660,10 @@ static void hugepage_restore_settings_atexit(void)
 
 static void hugepage_restore_settings_sighandler(int sig)
 {
+	(void)sig;
+
 	/* exit() will invoke the hugepage_restore_settings_atexit handler. */
-	exit(KSFT_FAIL);
+	exit(EXIT_FAILURE);
 }
 
 void hugepage_save_settings(bool thp, bool hugetlb)

tools/testing/selftests/mm/Makefile

@@ -185,8 +185,10 @@ TEST_FILES += write_hugetlb_memory.sh
 
 include ../lib.mk
 
-$(TEST_GEN_PROGS): vm_util.c hugepage_settings.c $(top_srcdir)/tools/lib/mm/file_utils.c
-$(TEST_GEN_FILES): vm_util.c hugepage_settings.c $(top_srcdir)/tools/lib/mm/file_utils.c
+$(TEST_GEN_PROGS): vm_util.c $(top_srcdir)/tools/lib/mm/hugepage_settings.c \
+		   $(top_srcdir)/tools/lib/mm/file_utils.c
+$(TEST_GEN_FILES): vm_util.c $(top_srcdir)/tools/lib/mm/hugepage_settings.c \
+		   $(top_srcdir)/tools/lib/mm/file_utils.c
 
 $(OUTPUT)/uffd-stress: uffd-common.c
 $(OUTPUT)/uffd-unit-tests: uffd-common.c

tools/testing/selftests/mm/compaction_test.c

@@ -15,9 +15,9 @@
 #include <errno.h>
 #include <unistd.h>
 #include <string.h>
+#include <mm/hugepage_settings.h>
 
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 #define MAP_SIZE_MB	100
 #define MAP_SIZE	(MAP_SIZE_MB * 1024 * 1024)

tools/testing/selftests/mm/cow.c

@@ -29,7 +29,6 @@
 #include "../../../../mm/gup_test.h"
 #include "kselftest.h"
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 static size_t pagesize;
 static int pagemap_fd;

tools/testing/selftests/mm/folio_split_race_test.c

@@ -25,7 +25,6 @@
 #include <unistd.h>
 #include "vm_util.h"
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 uint64_t page_size;
 uint64_t pmd_pagesize;

tools/testing/selftests/mm/guard-regions.c

@@ -21,7 +21,6 @@
 #include <sys/uio.h>
 #include <unistd.h>
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 #include "../pidfd/pidfd.h"
 

tools/testing/selftests/mm/gup_longterm.c

@@ -29,7 +29,6 @@
 #include "../../../../mm/gup_test.h"
 #include "kselftest.h"
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 static size_t pagesize;
 static int nr_hugetlbsizes;

tools/testing/selftests/mm/gup_test.c

@@ -14,7 +14,6 @@
 #include <mm/gup_test.h>
 #include "kselftest.h"
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 #define MB (1UL << 20)
 

tools/testing/selftests/mm/hmm-tests.c

@@ -10,9 +10,6 @@
  * bugs.
  */
 
-#include "kselftest_harness.h"
-#include "hugepage_settings.h"
-
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
@@ -33,6 +30,9 @@
 #include <sys/eventfd.h>
 #include <linux/userfaultfd.h>
 #include <poll.h>
+#include <mm/hugepage_settings.h>
+
+#include "kselftest_harness.h"
 
 /*
  * This is a private UAPI to the kernel test module so it isn't exported

tools/testing/selftests/mm/hugetlb-madvise.c

@@ -14,7 +14,6 @@
 #include <fcntl.h>
 #include "vm_util.h"
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 #define MIN_FREE_PAGES	20
 #define NR_HUGE_PAGES	10	/* common number of pages to map/allocate */

tools/testing/selftests/mm/hugetlb-mmap.c

@@ -18,7 +18,6 @@
 #include <linux/memfd.h>
 #include "vm_util.h"
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 #define LENGTH (256UL*1024*1024)
 #define PROTECTION (PROT_READ | PROT_WRITE)

tools/testing/selftests/mm/hugetlb-mremap.c

@@ -26,7 +26,6 @@
 #include <stdbool.h>
 #include "kselftest.h"
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 #define DEFAULT_LENGTH_MB 10UL
 #define MB_TO_BYTES(x) (x * 1024 * 1024)

tools/testing/selftests/mm/hugetlb-shm.c

@@ -29,7 +29,6 @@
 #include <sys/mman.h>
 
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 #define LENGTH (256UL*1024*1024)
 

tools/testing/selftests/mm/hugetlb-soft-offline.c

@@ -22,10 +22,10 @@
 #include <sys/mman.h>
 #include <sys/statfs.h>
 #include <sys/types.h>
+#include <mm/hugepage_settings.h>
 
 #include "kselftest.h"
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 #ifndef MADV_SOFT_OFFLINE
 #define MADV_SOFT_OFFLINE 101

tools/testing/selftests/mm/hugetlb_dio.c

@@ -20,7 +20,6 @@
 #include <sys/syscall.h>
 #include "vm_util.h"
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 #ifndef STATX_DIOALIGN
 #define STATX_DIOALIGN		0x00002000U

tools/testing/selftests/mm/hugetlb_fault_after_madv.c

@@ -10,7 +10,6 @@
 
 #include "vm_util.h"
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 #define INLOOP_ITER 100
 

tools/testing/selftests/mm/hugetlb_madv_vs_map.c

@@ -14,7 +14,6 @@
 #include <unistd.h>
 
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 #define INLOOP_ITER 100
 

tools/testing/selftests/mm/khugepaged.c

@@ -22,7 +22,6 @@
 #include "linux/magic.h"
 
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 #define BASE_ADDR ((void *)(1UL << 30))
 static unsigned long hpage_pmd_size;

tools/testing/selftests/mm/ksm_tests.c

@@ -15,7 +15,6 @@
 #include "kselftest.h"
 #include <include/vdso/time64.h>
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 #define KSM_SYSFS_PATH "/sys/kernel/mm/ksm/"
 #define KSM_FP(s) (KSM_SYSFS_PATH s)

tools/testing/selftests/mm/migration.c

@@ -5,7 +5,6 @@
  */
 
 #include "kselftest_harness.h"
-#include "hugepage_settings.h"
 
 #include <string.h>
 #include <pthread.h>
@@ -16,6 +15,7 @@
 #include <sys/types.h>
 #include <signal.h>
 #include <time.h>
+
 #include "vm_util.h"
 
 #define TWOMEG		(2<<20)

tools/testing/selftests/mm/pagemap_ioctl.c

@@ -24,7 +24,6 @@
 
 #include "vm_util.h"
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 #define PAGEMAP_BITS_ALL		(PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN |	\
 					 PAGE_IS_FILE | PAGE_IS_PRESENT |	\

tools/testing/selftests/mm/prctl_thp_disable.c

@@ -14,7 +14,6 @@
 #include <sys/wait.h>
 
 #include "kselftest_harness.h"
-#include "hugepage_settings.h"
 #include "vm_util.h"
 
 #ifndef PR_THP_DISABLE_EXCEPT_ADVISED

tools/testing/selftests/mm/protection_keys.c

@@ -45,8 +45,8 @@
 #include <unistd.h>
 #include <sys/ptrace.h>
 #include <setjmp.h>
+#include <mm/hugepage_settings.h>
 
-#include "hugepage_settings.h"
 #include "pkey-helpers.h"
 
 u64 shadow_pkey_reg;

tools/testing/selftests/mm/soft-dirty.c

@@ -9,7 +9,6 @@
 
 #include "kselftest.h"
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 #define PAGEMAP_FILE_PATH "/proc/self/pagemap"
 #define TEST_ITERATIONS 10000

tools/testing/selftests/mm/split_huge_page_test.c

@@ -21,7 +21,6 @@
 #include <time.h>
 #include "vm_util.h"
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 uint64_t pagesize;
 unsigned int pageshift;

tools/testing/selftests/mm/thuge-gen.c

@@ -14,7 +14,6 @@
 #include <string.h>
 #include "vm_util.h"
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 #if !defined(MAP_HUGETLB)
 #define MAP_HUGETLB	0x40000

tools/testing/selftests/mm/transhuge-stress.c

@@ -17,7 +17,6 @@
 #include <sys/mman.h>
 #include "vm_util.h"
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 int backing_fd = -1;
 int mmap_flags = MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE;

tools/testing/selftests/mm/uffd-common.h

@@ -37,7 +37,6 @@
 
 #include "kselftest.h"
 #include "vm_util.h"
-#include "hugepage_settings.h"
 
 #define UFFD_FLAGS	(O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY)
 

tools/testing/selftests/mm/uffd-wp-mremap.c

@@ -7,8 +7,8 @@
 #include <assert.h>
 #include <linux/mman.h>
 #include <sys/mman.h>
+#include <mm/hugepage_settings.h>
 #include "kselftest.h"
-#include "hugepage_settings.h"
 #include "uffd-common.h"
 
 static int pagemap_fd;

tools/testing/selftests/mm/va_high_addr_switch.c

@@ -11,7 +11,6 @@
 
 #include "vm_util.h"
 #include "kselftest.h"
-#include "hugepage_settings.h"
 
 /*
  * The hint addr value is used to allocate addresses

tools/testing/selftests/mm/vm_util.h

@@ -9,6 +9,7 @@
 #include "kselftest.h"
 #include <linux/fs.h>
 #include <mm/file_utils.h>
+#include <mm/hugepage_settings.h>
 
 #define BIT_ULL(nr)                   (1ULL << (nr))
 #define PM_SOFT_DIRTY                 BIT_ULL(55)