4 files changed, 134 insertions, 0 deletions

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 050151144596..89b05e2222c9 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -6,6 +6,7 @@ TARGETS += firmware
 TARGETS += ftrace
 TARGETS += futex
 TARGETS += kcmp
+TARGETS += membarrier
 TARGETS += memfd
 TARGETS += memory-hotplug
 TARGETS += mount
diff --git a/tools/testing/selftests/membarrier/.gitignore b/tools/testing/selftests/membarrier/.gitignore
new file mode 100644
index 000000000000..020c44f49a9e
--- /dev/null
+++ b/tools/testing/selftests/membarrier/.gitignore
@@ -0,0 +1 @@
+membarrier_test
diff --git a/tools/testing/selftests/membarrier/Makefile b/tools/testing/selftests/membarrier/Makefile
new file mode 100644
index 000000000000..877a50355d7f
--- /dev/null
+++ b/tools/testing/selftests/membarrier/Makefile
@@ -0,0 +1,11 @@
+CFLAGS += -g -I../../../../usr/include/
+
+all:
+        $(CC) $(CFLAGS) membarrier_test.c -o membarrier_test
+
+TEST_PROGS := membarrier_test
+
+include ../lib.mk
+
+clean:
+        $(RM) membarrier_test
diff --git a/tools/testing/selftests/membarrier/membarrier_test.c b/tools/testing/selftests/membarrier/membarrier_test.c
new file mode 100644
index 000000000000..dde312508007
--- /dev/null
+++ b/tools/testing/selftests/membarrier/membarrier_test.c
@@ -0,0 +1,121 @@
+#define _GNU_SOURCE
+#define __EXPORTED_HEADERS__
+
+#include <linux/membarrier.h>
+#include <asm-generic/unistd.h>
+#include <sys/syscall.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+#include "../kselftest.h"
+
+enum test_membarrier_status {
+        TEST_MEMBARRIER_PASS = 0,
+        TEST_MEMBARRIER_FAIL,
+        TEST_MEMBARRIER_SKIP,
+};
+
+static int sys_membarrier(int cmd, int flags)
+{
+        return syscall(__NR_membarrier, cmd, flags);
+}
+
+static enum test_membarrier_status test_membarrier_cmd_fail(void)
+{
+        int cmd = -1, flags = 0;
+
+        if (sys_membarrier(cmd, flags) != -1) {
+                printf("membarrier: Wrong command should fail but passed.\n");
+                return TEST_MEMBARRIER_FAIL;
+        }
+        return TEST_MEMBARRIER_PASS;
+}
+
+static enum test_membarrier_status test_membarrier_flags_fail(void)
+{
+        int cmd = MEMBARRIER_CMD_QUERY, flags = 1;
+
+        if (sys_membarrier(cmd, flags) != -1) {
+                printf("membarrier: Wrong flags should fail but passed.\n");
+                return TEST_MEMBARRIER_FAIL;
+        }
+        return TEST_MEMBARRIER_PASS;
+}
+
+static enum test_membarrier_status test_membarrier_success(void)
+{
+        int cmd = MEMBARRIER_CMD_SHARED, flags = 0;
+
+        if (sys_membarrier(cmd, flags) != 0) {
+                printf("membarrier: Executing MEMBARRIER_CMD_SHARED failed. %s.\n",
+                                strerror(errno));
+                return TEST_MEMBARRIER_FAIL;
+        }
+
+        printf("membarrier: MEMBARRIER_CMD_SHARED success.\n");
+        return TEST_MEMBARRIER_PASS;
+}
+
+static enum test_membarrier_status test_membarrier(void)
+{
+        enum test_membarrier_status status;
+
+        status = test_membarrier_cmd_fail();
+        if (status)
+                return status;
+        status = test_membarrier_flags_fail();
+        if (status)
+                return status;
+        status = test_membarrier_success();
+        if (status)
+                return status;
+        return TEST_MEMBARRIER_PASS;
+}
+
+static enum test_membarrier_status test_membarrier_query(void)
+{
+        int flags = 0, ret;
+
+        printf("membarrier MEMBARRIER_CMD_QUERY ");
+        ret = sys_membarrier(MEMBARRIER_CMD_QUERY, flags);
+        if (ret < 0) {
+                printf("failed. %s.\n", strerror(errno));
+                switch (errno) {
+                case ENOSYS:
+                        /*
+                         * It is valid to build a kernel with
+                         * CONFIG_MEMBARRIER=n. However, this skips the tests.
+                         */
+                        return TEST_MEMBARRIER_SKIP;
+                case EINVAL:
+                default:
+                        return TEST_MEMBARRIER_FAIL;
+                }
+        }
+        if (!(ret & MEMBARRIER_CMD_SHARED)) {
+                printf("command MEMBARRIER_CMD_SHARED is not supported.\n");
+                return TEST_MEMBARRIER_FAIL;
+        }
+        printf("syscall available.\n");
+        return TEST_MEMBARRIER_PASS;
+}
+
+int main(int argc, char **argv)
+{
+        switch (test_membarrier_query()) {
+        case TEST_MEMBARRIER_FAIL:
+                return ksft_exit_fail();
+        case TEST_MEMBARRIER_SKIP:
+                return ksft_exit_skip();
+        }
+        switch (test_membarrier()) {
+        case TEST_MEMBARRIER_FAIL:
+                return ksft_exit_fail();
+        case TEST_MEMBARRIER_SKIP:
+                return ksft_exit_skip();
+        }
+
+        printf("membarrier: tests done!\n");
+        return ksft_exit_pass();
+}