selftests/mm: move certain uffd*() routines from vm_util.c to uffd-common.c

There are only three uffd*() routines that are used outside of the uffd
selftests. Leave these in vm_util.c, where they are available to any mm
selftest program:

    uffd_register()
    uffd_unregister()
    uffd_register_with_ioctls().

A few other uffd*() routines, however, are only used by the uffd-focused
tests found in uffd-stress.c and uffd-unit-tests.c. Move those routines
into uffd-common.c.

Link: https://lkml.kernel.org/r/20230606071637.267103-10-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
index 61c6250..ba20d75 100644 (file)
--- a/tools/testing/selftests/mm/uffd-common.c
+++ b/tools/testing/selftests/mm/uffd-common.c
@@ -616,3 +616,62 @@ int copy_page(int ufd, unsigned long offset, bool wp)
 {
        return __copy_page(ufd, offset, false, wp);
 }
+
+int uffd_open_dev(unsigned int flags)
+{
+       int fd, uffd;
+
+       fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC);
+       if (fd < 0)
+               return fd;
+       uffd = ioctl(fd, USERFAULTFD_IOC_NEW, flags);
+       close(fd);
+
+       return uffd;
+}
+
+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)
+{
+       int uffd = uffd_open_sys(flags);
+
+       if (uffd < 0)
+               uffd = uffd_open_dev(flags);
+
+       return uffd;
+}
+
+int uffd_get_features(uint64_t *features)
+{
+       struct uffdio_api uffdio_api = { .api = UFFD_API, .features = 0 };
+       /*
+        * This should by default work in most kernels; the feature list
+        * will be the same no matter what we pass in here.
+        */
+       int fd = uffd_open(UFFD_USER_MODE_ONLY);
+
+       if (fd < 0)
+               /* Maybe the kernel is older than user-only mode? */
+               fd = uffd_open(0);
+
+       if (fd < 0)
+               return fd;
+
+       if (ioctl(fd, UFFDIO_API, &uffdio_api)) {
+               close(fd);
+               return -errno;
+       }
+
+       *features = uffdio_api.features;
+       close(fd);
+
+       return 0;
+}

diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h
index 6068f23..197f526 100644 (file)
--- a/tools/testing/selftests/mm/uffd-common.h
+++ b/tools/testing/selftests/mm/uffd-common.h
@@ -110,6 +110,11 @@ int __copy_page(int ufd, unsigned long offset, bool retry, bool wp);
 int copy_page(int ufd, unsigned long offset, bool wp);
 void *uffd_poll_thread(void *arg);
 
+int uffd_open_dev(unsigned int flags);
+int uffd_open_sys(unsigned int flags);
+int uffd_open(unsigned int flags);
+int uffd_get_features(uint64_t *features);
+
 #define TEST_ANON      1
 #define TEST_HUGETLB   2
 #define TEST_SHMEM     3

diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
index 5cf84d8..558c9cd 100644 (file)
--- a/tools/testing/selftests/mm/vm_util.c
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -269,62 +269,3 @@ int uffd_unregister(int uffd, void *addr, uint64_t len)
 
        return ret;
 }
-
-int uffd_open_dev(unsigned int flags)
-{
-       int fd, uffd;
-
-       fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC);
-       if (fd < 0)
-               return fd;
-       uffd = ioctl(fd, USERFAULTFD_IOC_NEW, flags);
-       close(fd);
-
-       return uffd;
-}
-
-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)
-{
-       int uffd = uffd_open_sys(flags);
-
-       if (uffd < 0)
-               uffd = uffd_open_dev(flags);
-
-       return uffd;
-}
-
-int uffd_get_features(uint64_t *features)
-{
-       struct uffdio_api uffdio_api = { .api = UFFD_API, .features = 0 };
-       /*
-        * This should by default work in most kernels; the feature list
-        * will be the same no matter what we pass in here.
-        */
-       int fd = uffd_open(UFFD_USER_MODE_ONLY);
-
-       if (fd < 0)
-               /* Maybe the kernel is older than user-only mode? */
-               fd = uffd_open(0);
-
-       if (fd < 0)
-               return fd;
-
-       if (ioctl(fd, UFFDIO_API, &uffdio_api)) {
-               close(fd);
-               return -errno;
-       }
-
-       *features = uffdio_api.features;
-       close(fd);
-
-       return 0;
-}

diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h
index 0df1cf7..e57ace1 100644 (file)
--- a/tools/testing/selftests/mm/vm_util.h
+++ b/tools/testing/selftests/mm/vm_util.h
@@ -49,10 +49,6 @@ int detect_hugetlb_page_sizes(size_t sizes[], int max);
 int uffd_register(int uffd, void *addr, uint64_t len,
                  bool miss, bool wp, bool minor);
 int uffd_unregister(int uffd, void *addr, uint64_t len);
-int uffd_open_dev(unsigned int flags);
-int uffd_open_sys(unsigned int flags);
-int uffd_open(unsigned int flags);
-int uffd_get_features(uint64_t *features);
 int uffd_register_with_ioctls(int uffd, void *addr, uint64_t len,
                              bool miss, bool wp, bool minor, uint64_t *ioctls);