@@ -77,6 +77,11 @@ static int bounces;
#define TEST_SHMEM 3
static int test_type;
+#define UFFD_FLAGS (O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY)
+
+/* test using /dev/userfaultfd, instead of userfaultfd(2) */
+static bool test_dev_userfaultfd;
+
/* exercise the test_uffdio_*_eexist every ALARM_INTERVAL_SECS */
#define ALARM_INTERVAL_SECS 10
static volatile bool test_uffdio_copy_eexist = true;
@@ -125,6 +130,8 @@ struct uffd_stats {
const char *examples =
"# Run anonymous memory test on 100MiB region with 99999 bounces:\n"
"./userfaultfd anon 100 99999\n\n"
+ "# Run the same anonymous memory test, but using /dev/userfaultfd:\n"
+ "./userfaultfd anon:dev 100 99999\n\n"
"# Run share memory test on 1GiB region with 99 bounces:\n"
"./userfaultfd shmem 1000 99\n\n"
"# Run hugetlb memory test on 256MiB region with 50 bounces:\n"
@@ -141,6 +148,14 @@ static void usage(void)
"[hugetlbfs_file]\n\n");
fprintf(stderr, "Supported <test type>: anon, hugetlb, "
"hugetlb_shared, shmem\n\n");
+ fprintf(stderr, "'Test mods' can be joined to the test type string with a ':'. "
+ "Supported mods:\n");
+ fprintf(stderr, "\tsyscall - Use userfaultfd(2) (default)\n");
+ fprintf(stderr, "\tdev - Use /dev/userfaultfd instead of userfaultfd(2)\n");
+ fprintf(stderr, "\nExample test mod usage:\n");
+ fprintf(stderr, "# Run anonymous memory test with /dev/userfaultfd:\n");
+ fprintf(stderr, "./userfaultfd anon:dev 100 99999\n\n");
+
fprintf(stderr, "Examples:\n\n");
fprintf(stderr, "%s", examples);
exit(1);
@@ -154,12 +169,14 @@ static void usage(void)
ret, __LINE__); \
} while (0)
-#define err(fmt, ...) \
+#define errexit(exitcode, fmt, ...) \
do { \
_err(fmt, ##__VA_ARGS__); \
- exit(1); \
+ exit(exitcode); \
} while (0)
+#define err(fmt, ...) errexit(1, fmt, ##__VA_ARGS__)
+
static void uffd_stats_reset(struct uffd_stats *uffd_stats,
unsigned long n_cpus)
{
@@ -383,13 +400,34 @@ static void assert_expected_ioctls_present(uint64_t mode, uint64_t ioctls)
}
}
+static int __userfaultfd_open_dev(void)
+{
+ int fd, _uffd;
+
+ fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC);
+ if (fd < 0)
+ errexit(KSFT_SKIP, "opening /dev/userfaultfd failed");
+
+ _uffd = ioctl(fd, USERFAULTFD_IOC_NEW, UFFD_FLAGS);
+ if (_uffd < 0)
+ errexit(errno == ENOTTY ? KSFT_SKIP : 1,
+ "creating userfaultfd failed");
+ close(fd);
+ return _uffd;
+}
+
static void userfaultfd_open(uint64_t *features)
{
struct uffdio_api uffdio_api;
- uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY);
- if (uffd < 0)
- err("userfaultfd syscall not available in this kernel");
+ if (test_dev_userfaultfd)
+ uffd = __userfaultfd_open_dev();
+ else {
+ uffd = syscall(__NR_userfaultfd, UFFD_FLAGS);
+ if (uffd < 0)
+ errexit(errno == ENOSYS ? KSFT_SKIP : 1,
+ "creating userfaultfd failed");
+ }
uffd_flags = fcntl(uffd, F_GETFD, NULL);
uffdio_api.api = UFFD_API;
@@ -1584,8 +1622,6 @@ unsigned long default_huge_page_size(void)
static void set_test_type(const char *type)
{
- uint64_t features = UFFD_API_FEATURES;
-
if (!strcmp(type, "anon")) {
test_type = TEST_ANON;
uffd_test_ops = &anon_uffd_test_ops;
@@ -1603,9 +1639,29 @@ static void set_test_type(const char *type)
test_type = TEST_SHMEM;
uffd_test_ops = &shmem_uffd_test_ops;
test_uffdio_minor = true;
- } else {
- err("Unknown test type: %s", type);
}
+}
+
+static void parse_test_type_arg(const char *raw_type)
+{
+ char *buf = strdup(raw_type);
+ uint64_t features = UFFD_API_FEATURES;
+
+ while (buf) {
+ const char *token = strsep(&buf, ":");
+
+ if (!test_type)
+ set_test_type(token);
+ else if (!strcmp(token, "dev"))
+ test_dev_userfaultfd = true;
+ else if (!strcmp(token, "syscall"))
+ test_dev_userfaultfd = false;
+ else
+ err("unrecognized test mod '%s'", token);
+ }
+
+ if (!test_type)
+ err("failed to parse test type argument: '%s'", raw_type);
if (test_type == TEST_HUGETLB)
page_size = default_huge_page_size();
@@ -1653,7 +1709,7 @@ int main(int argc, char **argv)
err("failed to arm SIGALRM");
alarm(ALARM_INTERVAL_SECS);
- set_test_type(argv[1]);
+ parse_test_type_arg(argv[1]);
nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
nr_pages_per_cpu = atol(argv[2]) * 1024*1024 / page_size /