diff --git a/tools/testing/selftests/mm/hugepage-mremap.c b/tools/testing/selftests/mm/hugepage-mremap.c
index c463d1c09c9b..2893bc002639 100644
--- a/tools/testing/selftests/mm/hugepage-mremap.c
+++ b/tools/testing/selftests/mm/hugepage-mremap.c
@@ -15,7 +15,7 @@
 #define _GNU_SOURCE
 #include <stdlib.h>
 #include <stdio.h>
-#include <unistd.h>
+#include <linux/unistd.h>
 #include <sys/mman.h>
 #include <errno.h>
 #include <fcntl.h> /* Definition of O_* constants */
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c
index 37de82da9be7..1d584a415bde 100644
--- a/tools/testing/selftests/mm/ksm_functional_tests.c
+++ b/tools/testing/selftests/mm/ksm_functional_tests.c
@@ -11,7 +11,7 @@
 #include <string.h>
 #include <stdbool.h>
 #include <stdint.h>
-#include <unistd.h>
+#include <linux/unistd.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/mman.h>
@@ -369,7 +369,6 @@ static void test_unmerge_discarded(void)
 	munmap(map, size);
 }
 
-#ifdef __NR_userfaultfd
 static void test_unmerge_uffd_wp(void)
 {
 	struct uffdio_writeprotect uffd_writeprotect;
@@ -430,7 +429,6 @@ static void test_unmerge_uffd_wp(void)
 unmap:
 	munmap(map, size);
 }
-#endif
 
 /* Verify that KSM can be enabled / queried with prctl. */
 static void test_prctl(void)
@@ -665,9 +663,7 @@ int main(int argc, char **argv)
 		exit(test_child_ksm());
 	}
 
-#ifdef __NR_userfaultfd
 	tests++;
-#endif
 
 	ksft_print_header();
 	ksft_set_plan(tests);
@@ -694,9 +690,7 @@ int main(int argc, char **argv)
 	test_unmerge();
 	test_unmerge_zero_pages();
 	test_unmerge_discarded();
-#ifdef __NR_userfaultfd
 	test_unmerge_uffd_wp();
-#endif
 
 	test_prot_none();
 
diff --git a/tools/testing/selftests/mm/memfd_secret.c b/tools/testing/selftests/mm/memfd_secret.c
index 9a0597310a76..1fcf65c08c87 100644
--- a/tools/testing/selftests/mm/memfd_secret.c
+++ b/tools/testing/selftests/mm/memfd_secret.c
@@ -17,7 +17,7 @@
 
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
+#include <linux/unistd.h>
 #include <errno.h>
 #include <stdio.h>
 #include <fcntl.h>
@@ -28,8 +28,6 @@
 #define pass(fmt, ...) ksft_test_result_pass(fmt, ##__VA_ARGS__)
 #define skip(fmt, ...) ksft_test_result_skip(fmt, ##__VA_ARGS__)
 
-#ifdef __NR_memfd_secret
-
 #define PATTERN	0x55
 
 static const int prot = PROT_READ | PROT_WRITE;
@@ -334,13 +332,3 @@ int main(int argc, char *argv[])
 
 	ksft_finished();
 }
-
-#else /* __NR_memfd_secret */
-
-int main(int argc, char *argv[])
-{
-	printf("skip: skipping memfd_secret test (missing __NR_memfd_secret)\n");
-	return KSFT_SKIP;
-}
-
-#endif /* __NR_memfd_secret */
diff --git a/tools/testing/selftests/mm/mkdirty.c b/tools/testing/selftests/mm/mkdirty.c
index b8a7efe9204e..7dde5b9a9ef5 100644
--- a/tools/testing/selftests/mm/mkdirty.c
+++ b/tools/testing/selftests/mm/mkdirty.c
@@ -9,7 +9,7 @@
  */
 #include <fcntl.h>
 #include <signal.h>
-#include <unistd.h>
+#include <linux/unistd.h>
 #include <string.h>
 #include <errno.h>
 #include <stdlib.h>
@@ -265,7 +265,6 @@ static void test_pte_mapped_thp(void)
 	munmap(mmap_mem, mmap_size);
 }
 
-#ifdef __NR_userfaultfd
 static void test_uffdio_copy(void)
 {
 	struct uffdio_register uffdio_register;
@@ -322,7 +321,6 @@ static void test_uffdio_copy(void)
 	munmap(dst, pagesize);
 	free(src);
 }
-#endif /* __NR_userfaultfd */
 
 int main(void)
 {
@@ -335,9 +333,7 @@ int main(void)
 			       thpsize / 1024);
 		tests += 3;
 	}
-#ifdef __NR_userfaultfd
 	tests += 1;
-#endif /* __NR_userfaultfd */
 
 	ksft_print_header();
 	ksft_set_plan(tests);
@@ -367,9 +363,7 @@ int main(void)
 	if (thpsize)
 		test_pte_mapped_thp();
 	/* Placing a fresh page via userfaultfd may set the PTE dirty. */
-#ifdef __NR_userfaultfd
 	test_uffdio_copy();
-#endif /* __NR_userfaultfd */
 
 	err = ksft_get_fail_cnt();
 	if (err)
diff --git a/tools/testing/selftests/mm/mlock2.h b/tools/testing/selftests/mm/mlock2.h
index 4417eaa5cfb7..b74ddf0a2c39 100644
--- a/tools/testing/selftests/mm/mlock2.h
+++ b/tools/testing/selftests/mm/mlock2.h
@@ -3,6 +3,7 @@
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <linux/unistd.h>
 
 static int mlock2_(void *start, size_t len, int flags)
 {
diff --git a/tools/testing/selftests/mm/mrelease_test.c b/tools/testing/selftests/mm/mrelease_test.c
index 100370a7111d..a1b761940058 100644
--- a/tools/testing/selftests/mm/mrelease_test.c
+++ b/tools/testing/selftests/mm/mrelease_test.c
@@ -10,7 +10,7 @@
 #include <sys/syscall.h>
 #include <sys/wait.h>
 #include <unistd.h>
-#include <asm-generic/unistd.h>
+#include <linux/unistd.h>
 #include "vm_util.h"
 #include "../kselftest.h"
 
diff --git a/tools/testing/selftests/mm/pagemap_ioctl.c b/tools/testing/selftests/mm/pagemap_ioctl.c
index 2d785aca72a5..5652e5930854 100644
--- a/tools/testing/selftests/mm/pagemap_ioctl.c
+++ b/tools/testing/selftests/mm/pagemap_ioctl.c
@@ -15,7 +15,7 @@
 #include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <math.h>
-#include <asm/unistd.h>
+#include <linux/unistd.h>
 #include <pthread.h>
 #include <sys/resource.h>
 #include <assert.h>
diff --git a/tools/testing/selftests/mm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c
index 48dc151f8fca..ec968db9e6c7 100644
--- a/tools/testing/selftests/mm/protection_keys.c
+++ b/tools/testing/selftests/mm/protection_keys.c
@@ -42,7 +42,7 @@
 #include <sys/wait.h>
 #include <sys/stat.h>
 #include <fcntl.h>
-#include <unistd.h>
+#include <linux/unistd.h>
 #include <sys/ptrace.h>
 #include <setjmp.h>
 
diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
index 7ad6ba660c7d..717539eddf98 100644
--- a/tools/testing/selftests/mm/uffd-common.c
+++ b/tools/testing/selftests/mm/uffd-common.c
@@ -673,11 +673,7 @@ int uffd_open_dev(unsigned int flags)
 
 int uffd_open_sys(unsigned int flags)
 {
-#ifdef __NR_userfaultfd
 	return syscall(__NR_userfaultfd, flags);
-#else
-	return -1;
-#endif
 }
 
 int uffd_open(unsigned int flags)
diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index f78bab0f3d45..6aff0e8cd961 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -33,11 +33,9 @@
  * pthread_mutex_lock will also verify the atomicity of the memory
  * transfer (UFFDIO_COPY).
  */
-
+#include <linux/unistd.h>
 #include "uffd-common.h"
 
-#ifdef __NR_userfaultfd
-
 #define BOUNCE_RANDOM		(1<<0)
 #define BOUNCE_RACINGFAULTS	(1<<1)
 #define BOUNCE_VERIFY		(1<<2)
@@ -466,15 +464,3 @@ int main(int argc, char **argv)
 	       nr_pages, nr_pages_per_cpu);
 	return userfaultfd_stress();
 }
-
-#else /* __NR_userfaultfd */
-
-#warning "missing __NR_userfaultfd definition"
-
-int main(void)
-{
-	printf("skip: Skipping userfaultfd test (missing __NR_userfaultfd)\n");
-	return KSFT_SKIP;
-}
-
-#endif /* __NR_userfaultfd */
diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
index 21ec23206ab4..6298a2045095 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -5,12 +5,11 @@
  *  Copyright (C) 2015-2023  Red Hat, Inc.
  */
 
+#include <linux/unistd.h>
 #include "uffd-common.h"
 
 #include "../../../../mm/gup_test.h"
 
-#ifdef __NR_userfaultfd
-
 /* The unit test doesn't need a large or random size, make it 32MB for now */
 #define  UFFD_TEST_MEM_SIZE               (32UL << 20)
 
@@ -1554,14 +1553,3 @@ int main(int argc, char *argv[])
 	return ksft_get_fail_cnt() ? KSFT_FAIL : KSFT_PASS;
 }
 
-#else /* __NR_userfaultfd */
-
-#warning "missing __NR_userfaultfd definition"
-
-int main(void)
-{
-	printf("Skipping %s (missing __NR_userfaultfd)\n", __file__);
-	return KSFT_SKIP;
-}
-
-#endif /* __NR_userfaultfd */
