selftests/mm: pagemap_ioctl: use the correct page size for transact_test()

There are several places in transact_test() where we use the hardcoded
0x1000 (4k) as page size, which is not always correct for architectures
supporting multiple page sizes.

Switch to use the correct page size.  Otherwise ./ksft_pagemap.sh on a
16k-page-size arm64 box fails with

 $ ./ksft_pagemap.sh
 [...]
 # ok 96 mprotect_tests Both pages written after remap and mprotect
 # ok 97 mprotect_tests Clear and make the pages written
 # Bail out! ioctl failed
 # # Planned tests != run tests (117 != 97)
 # # Totals: pass:97 fail:0 xfail:0 xpass:0 skip:0 error:0
 # [FAIL]
 not ok 1 pagemap_ioctl # exit=1
 # SUMMARY: PASS=0 SKIP=0 FAIL=1
 1..1

Link: https://lore.kernel.org/20260628101118.35861-1-zenghui.yu@linux.dev
Fixes: 46fd75d4a3c9 ("selftests: mm: add pagemap ioctl tests")
Signed-off-by: Zenghui Yu <zenghui.yu@linux.dev>
Cc: Muhammad Usama Anjum <usama.anjum@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zenghui Yu <zenghui.yu@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/tools/testing/selftests/mm/pagemap_ioctl.c b/tools/testing/selftests/mm/pagemap_ioctl.c
index 762306177ad8..6f8971d5b3ce 100644
--- a/tools/testing/selftests/mm/pagemap_ioctl.c
+++ b/tools/testing/selftests/mm/pagemap_ioctl.c
@@ -1368,7 +1368,7 @@ void *thread_proc(void *mem)
 			ksft_exit_fail_msg("pthread_barrier_wait\n");
 
 		for (i = 0; i < access_per_thread; ++i)
-			__atomic_add_fetch(m + i * (0x1000 / sizeof(*m)), 1, __ATOMIC_SEQ_CST);
+			__atomic_add_fetch(m + i * (page_size / sizeof(*m)), 1, __ATOMIC_SEQ_CST);
 
 		ret = pthread_barrier_wait(&end_barrier);
 		if (ret && ret != PTHREAD_BARRIER_SERIAL_THREAD)
@@ -1403,15 +1403,15 @@ static void transact_test(int page_size)
 	if (pthread_barrier_init(&end_barrier, NULL, nthreads + 1))
 		ksft_exit_fail_msg("pthread_barrier_init\n");
 
-	mem = mmap(NULL, 0x1000 * nthreads * pages_per_thread, PROT_READ | PROT_WRITE,
+	mem = mmap(NULL, page_size * nthreads * pages_per_thread, PROT_READ | PROT_WRITE,
 		   MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
 	if (mem == MAP_FAILED)
 		ksft_exit_fail_msg("Error mmap %s.\n", strerror(errno));
 
-	wp_init(mem, 0x1000 * nthreads * pages_per_thread);
-	wp_addr_range(mem, 0x1000 * nthreads * pages_per_thread);
+	wp_init(mem, page_size * nthreads * pages_per_thread);
+	wp_addr_range(mem, page_size * nthreads * pages_per_thread);
 
-	memset(mem, 0, 0x1000 * nthreads * pages_per_thread);
+	memset(mem, 0, page_size * nthreads * pages_per_thread);
 
 	count = get_dirty_pages_reset(mem, nthreads * pages_per_thread, 1, page_size);
 	ksft_test_result(count > 0, "%s count %u\n", __func__, count);
@@ -1420,7 +1420,7 @@ static void transact_test(int page_size)
 
 	finish = 0;
 	for (i = 0; i < nthreads; ++i)
-		pthread_create(&th, NULL, thread_proc, mem + 0x1000 * i * pages_per_thread);
+		pthread_create(&th, NULL, thread_proc, mem + page_size * i * pages_per_thread);
 
 	extra_pages = 0;
 	for (i = 0; i < iter_count; ++i) {