[v2] syscalls/membarrier: Add membarrier() initial test

diff --git a/configure.ac b/configure.ac
index e1ecb32a7..98425f997 100644
--- a/configure.ac
+++ b/configure.ac
@@ -45,6 +45,7 @@  AC_CHECK_HEADERS([ \
     linux/mempolicy.h \
     linux/module.h \
     linux/netlink.h \
+    linux/membarrier.h \
     mm.h \
     netinet/sctp.h \
     pthread.h \
diff --git a/include/lapi/syscalls/aarch64.in b/include/lapi/syscalls/aarch64.in
index 9ac7f997b..f6b0b2949 100644
--- a/include/lapi/syscalls/aarch64.in
+++ b/include/lapi/syscalls/aarch64.in
@@ -256,6 +256,7 @@  sendmmsg 269
 kcmp 272
 getrandom 278
 memfd_create 279
+membarrier 283
 mlock2 284
 copy_file_range 285
 _sysctl 1078
diff --git a/include/lapi/syscalls/arm.in b/include/lapi/syscalls/arm.in
index 0a7f98ac5..d8897b180 100644
--- a/include/lapi/syscalls/arm.in
+++ b/include/lapi/syscalls/arm.in
@@ -341,6 +341,7 @@  renameat2 (__NR_SYSCALL_BASE+382)
 getrandom (__NR_SYSCALL_BASE+384)
 memfd_create (__NR_SYSCALL_BASE+385)
 execveat (__NR_SYSCALL_BASE+387)
+membarrier (__NR_SYSCALL_BASE+389)
 mlock2 (__NR_SYSCALL_BASE+390)
 copy_file_range (__NR_SYSCALL_BASE+391)
 statx (__NR_SYSCALL_BASE+397)
diff --git a/include/lapi/syscalls/hppa.in b/include/lapi/syscalls/hppa.in
index 3db978069..e961dabe3 100644
--- a/include/lapi/syscalls/hppa.in
+++ b/include/lapi/syscalls/hppa.in
@@ -17,5 +17,6 @@  splice 291
 tee 293
 vmsplice 294
 memfd_create 340
+membarrier 343
 mlock2 345
 copy_file_range 346
diff --git a/include/lapi/syscalls/i386.in b/include/lapi/syscalls/i386.in
index a000564d2..f2a4ae845 100644
--- a/include/lapi/syscalls/i386.in
+++ b/include/lapi/syscalls/i386.in
@@ -343,4 +343,5 @@  memfd_create 356
 execveat 358
 mlock2 376
 copy_file_range 377
+membarrier 375
 statx 383
diff --git a/include/lapi/syscalls/ia64.in b/include/lapi/syscalls/ia64.in
index 278819387..02f86d7d3 100644
--- a/include/lapi/syscalls/ia64.in
+++ b/include/lapi/syscalls/ia64.in
@@ -296,5 +296,6 @@  prlimit64 1325
 renameat2 1338
 getrandom 1339
 memfd_create 1340
+membarrier 1344
 mlock2 1346
 copy_file_range 1347
diff --git a/include/lapi/syscalls/powerpc.in b/include/lapi/syscalls/powerpc.in
index c0b4226eb..e8e5acb3b 100644
--- a/include/lapi/syscalls/powerpc.in
+++ b/include/lapi/syscalls/powerpc.in
@@ -347,6 +347,7 @@  sched_getattr 356
 renameat2 357
 getrandom 359
 memfd_create 360
+membarrier 365
 mlock2 378
 copy_file_range 379
 statx 383
diff --git a/include/lapi/syscalls/powerpc64.in b/include/lapi/syscalls/powerpc64.in
index c0b4226eb..e8e5acb3b 100644
--- a/include/lapi/syscalls/powerpc64.in
+++ b/include/lapi/syscalls/powerpc64.in
@@ -347,6 +347,7 @@  sched_getattr 356
 renameat2 357
 getrandom 359
 memfd_create 360
+membarrier 365
 mlock2 378
 copy_file_range 379
 statx 383
diff --git a/include/lapi/syscalls/s390.in b/include/lapi/syscalls/s390.in
index 47a04de27..8f0ba9278 100644
--- a/include/lapi/syscalls/s390.in
+++ b/include/lapi/syscalls/s390.in
@@ -331,6 +331,7 @@  sched_getattr 346
 renameat2 347
 getrandom 349
 memfd_create 350
+membarrier 356
 execveat 354
 mlock2 374
 copy_file_range 375
diff --git a/include/lapi/syscalls/s390x.in b/include/lapi/syscalls/s390x.in
index 83732ffbe..4fe69f41e 100644
--- a/include/lapi/syscalls/s390x.in
+++ b/include/lapi/syscalls/s390x.in
@@ -331,5 +331,6 @@  sched_getattr 346
 renameat2 347
 getrandom 349
 memfd_create 350
+membarrier 356
 mlock2 374
 copy_file_range 375
diff --git a/include/lapi/syscalls/sparc.in b/include/lapi/syscalls/sparc.in
index 2b06a797a..5f061b244 100644
--- a/include/lapi/syscalls/sparc.in
+++ b/include/lapi/syscalls/sparc.in
@@ -336,5 +336,6 @@  kcmp 341
 renameat2 345
 getrandom 347
 memfd_create 348
+membarrier 350
 mlock2 356
 copy_file_range 357
diff --git a/include/lapi/syscalls/sparc64.in b/include/lapi/syscalls/sparc64.in
index 8c8a86673..cb821e892 100644
--- a/include/lapi/syscalls/sparc64.in
+++ b/include/lapi/syscalls/sparc64.in
@@ -312,5 +312,6 @@  kcmp 341
 renameat2 345
 getrandom 347
 memfd_create 348
+membarrier 350
 mlock2 356
 copy_file_range 357
diff --git a/include/lapi/syscalls/x86_64.in b/include/lapi/syscalls/x86_64.in
index 4ce8477de..9a1832114 100644
--- a/include/lapi/syscalls/x86_64.in
+++ b/include/lapi/syscalls/x86_64.in
@@ -308,6 +308,7 @@  renameat2 316
 getrandom 318
 memfd_create 319
 execveat 322
+membarrier 324
 mlock2 325
 copy_file_range 326
 statx 332
diff --git a/runtest/syscalls b/runtest/syscalls
index 0d0be7713..19be14098 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1504,3 +1504,5 @@  statx02 statx02
 statx03 statx03
 statx04 statx04
 statx05 statx05
+
+membarrier01 membarrier01
diff --git a/testcases/kernel/syscalls/membarrier/.gitignore b/testcases/kernel/syscalls/membarrier/.gitignore
new file mode 100644
index 000000000..eec8058b9
--- /dev/null
+++ b/testcases/kernel/syscalls/membarrier/.gitignore
@@ -0,0 +1 @@ 
+/membarrier01
diff --git a/testcases/kernel/syscalls/membarrier/Makefile b/testcases/kernel/syscalls/membarrier/Makefile
new file mode 100644
index 000000000..f71e4fc25
--- /dev/null
+++ b/testcases/kernel/syscalls/membarrier/Makefile
@@ -0,0 +1,8 @@ 
+# Copyright (c) 2018 - Linaro Limited. All rights reserved.
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+top_srcdir		?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
\ No newline at end of file
diff --git a/testcases/kernel/syscalls/membarrier/membarrier01.c b/testcases/kernel/syscalls/membarrier/membarrier01.c
new file mode 100644
index 000000000..061e9ed7e
--- /dev/null
+++ b/testcases/kernel/syscalls/membarrier/membarrier01.c
@@ -0,0 +1,411 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2018 Linaro Limited. All rights reserved.
+ * Author: Rafael David Tinoco <rafael.tinoco@linaro.org>
+ */
+/*
+ * Basic tests for membarrier(2) syscall. Tests below are responsible for
+ * testing the membarrier(2) interface only, without checking if the barrier
+ * was successful or not. Check test_case structure for each test description.
+ */
+
+#include "config.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <syscall.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#ifdef HAVE_LINUX_MEMBARRIER_H
+# include <linux/membarrier.h>
+#endif
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+
+#ifdef HAVE_SYS_XATTR_H
+
+struct test_case {
+	char testname[80];
+	int command;		/* membarrier cmd                            */
+	int needregister;	/* membarrier cmd needs register cmd	     */
+	int flags;		/* flags for given membarrier cmd	     */
+	long exp_ret;		/* expected return code for given cmd        */
+	int exp_errno;		/* expected errno for given cmd failure      */
+	int enabled;		/* enabled, despite results from CMD_QUERY   */
+	int always;		/* CMD_QUERY should always enable this test  */
+	int force;		/* force if CMD_QUERY reports not enabled    */
+	int force_exp_errno;	/* expected errno after forced cmd           */
+};
+
+struct test_case tc[] = {
+	{
+	 /*
+	  * case 00) invalid cmd
+	  *     - enabled by default
+	  *     - should always fail with EINVAL
+	  */
+	 .testname = "cmd_fail",
+	 .command = -1,
+	 .exp_ret = -1,
+	 .exp_errno = EINVAL,
+	 .enabled = 1,
+	 },
+	{
+	 /*
+	  * case 01) invalid flags
+	  *     - enabled by default
+	  *     - should always fail with EINVAL
+	  */
+	 .testname = "cmd_flags_fail",
+	 .command = MEMBARRIER_CMD_QUERY,
+	 .flags = 1,
+	 .exp_ret = -1,
+	 .exp_errno = EINVAL,
+	 .enabled = 1,
+	 },
+	{
+	 /*
+	  * case 02) global barrier
+	  *     - should ALWAYS be enabled by CMD_QUERY
+	  *     - should always succeed
+	  */
+	 .testname = "cmd_global_success",
+	 .command = MEMBARRIER_CMD_GLOBAL,
+	 .flags = 0,
+	 .exp_ret = 0,
+	 .always = 1,
+	 },
+	 /*
+	  * commit 22e4ebb975 (v4.14-rc1) added cases 03, 04 and 05 features:
+	  */
+	{
+	 /*
+	  * case 03) private expedited barrier with no registrations
+	  *     - should fail with errno=EPERM due to no registrations
+	  *     - or be skipped if unsupported by running kernel
+	  */
+	 .testname = "cmd_private_expedited_fail",
+	 .command = MEMBARRIER_CMD_PRIVATE_EXPEDITED,
+	 .flags = 0,
+	 .exp_ret = -1,
+	 .exp_errno = EPERM,
+	 },
+	{
+	 /*
+	  * case 04) register private expedited
+	  *     - should succeed when supported by running kernel
+	  *     - or fail with errno=EINVAL if unsupported and forced
+	  */
+	 .testname = "cmd_private_expedited_register_success",
+	 .command = MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED,
+	 .flags = 0,
+	 .exp_ret = 0,
+	 .force = 1,
+	 .force_exp_errno = EINVAL,
+	 },
+	{
+	 /*
+	  * case 05) private expedited barrier with registration
+	  *     - should succeed due to existing registration
+	  *     - or fail with errno=EINVAL if unsupported and forced
+	  *     - NOTE: (a) if unsupported, and forced, < 4.16 , errno is EINVAL
+	  *     -       (b) if unsupported, and forced, >= 4.16, errno is EPERM
+	  */
+	 .testname = "cmd_private_expedited_success",
+	 .needregister = MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED,
+	 .command = MEMBARRIER_CMD_PRIVATE_EXPEDITED,
+	 .flags = 0,
+	 .exp_ret = 0,
+	 .force = 1,
+	 .force_exp_errno = EPERM,
+	 },
+	 /*
+	  * commit 70216e18e5 (v4.16-rc1) added cases 06, 07 and 08 features:
+	  */
+	{
+	 /*
+	  * case 06) private expedited sync core barrier with no registrations
+	  *     - should fail with errno=EPERM due to no registrations
+	  *     - or be skipped if unsupported by running kernel
+	  */
+	 .testname = "cmd_private_expedited_sync_core_fail",
+	 .command = MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE,
+	 .flags = 0,
+	 .exp_ret = -1,
+	 .exp_errno = EPERM,
+	 },
+	{
+	 /*
+	  * case 07) register private expedited sync core
+	  *     - should succeed when supported by running kernel
+	  *     - or fail with errno=EINVAL if unsupported and forced
+	  */
+	 .testname = "cmd_private_expedited_sync_core_register_success",
+	 .command = MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE,
+	 .flags = 0,
+	 .exp_ret = 0,
+	 .force = 1,
+	 .force_exp_errno = EINVAL,
+	 },
+	{
+	 /*
+	  * case 08) private expedited sync core barrier with registration
+	  *     - should succeed due to existing registration
+	  *     - or fail with errno=EINVAL if unsupported and forced
+	  */
+	 .testname = "cmd_private_expedited_sync_core_success",
+	 .needregister = MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE,
+	 .command = MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE,
+	 .flags = 0,
+	 .exp_ret = 0,
+	 .force = 1,
+	 .force_exp_errno = EINVAL,
+	 },
+	 /*
+	  * commit c5f58bd58f4 (v4.16-rc1) added cases 09, 10 and 11 features:
+	  */
+	{
+	 /*
+	  * case 09) global expedited barrier with no registrations
+	  *     - should never fail due to no registrations
+	  *     - or be skipped if unsupported by running kernel
+	  */
+	 .testname = "cmd_global_expedited_success",
+	 .command = MEMBARRIER_CMD_GLOBAL_EXPEDITED,
+	 .flags = 0,
+	 .exp_ret = 0,
+	 },
+	{
+	 /*
+	  * case 10) register global expedited
+	  *     - should succeed when supported by running kernel
+	  *     - or fail with errno=EINVAL if unsupported and forced
+	  */
+	 .testname = "cmd_global_expedited_register_success",
+	 .command = MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED,
+	 .flags = 0,
+	 .exp_ret = 0,
+	 .force = 1,
+	 .force_exp_errno = EINVAL,
+	 },
+	{
+	 /*
+	  * case 11) global expedited barrier with registration
+	  *     - should also succeed with registrations
+	  *     - or fail with errno=EINVAL if unsupported and forced
+	  */
+	 .testname = "cmd_global_expedited_success",
+	 .needregister = MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED,
+	 .command = MEMBARRIER_CMD_GLOBAL_EXPEDITED,
+	 .flags = 0,
+	 .exp_ret = 0,
+	 .force = 1,
+	 .force_exp_errno = EINVAL,
+	 },
+};
+
+#define passed_ok(_test)						       \
+	do {								       \
+		tst_res(TPASS, "membarrier(2): %s passed", _test.testname);    \
+		return;							       \
+	} while (0)
+
+#define passed_unexpec(_test)						       \
+	do {								       \
+		tst_res(TFAIL, "membarrier(2): %s passed unexpectedly. "       \
+			"ret = %ld with errno %d were expected. (force: %d)",  \
+			_test.testname, _test.exp_ret, _test.exp_errno,        \
+			_test.force);					       \
+		return;							       \
+	} while (0)
+
+#define failed_ok(_test)						       \
+	do {								       \
+		tst_res(TPASS, "membarrier(2): %s failed as expected",	       \
+			_test.testname);				       \
+		return;							       \
+	} while (0)
+
+#define failed_ok_unsupported(_test)					       \
+	do {								       \
+		tst_res(TPASS, "membarrier(2): %s failed as expected "	       \
+			"(unsupported)", _test.testname);		       \
+		return;							       \
+	} while (0)
+
+#define failed_not_ok(_test, _gotret, _goterr)				       \
+	do {								       \
+		tst_res(TFAIL, "membarrier(2): %s failed. "		       \
+			"ret = %ld when expected was %ld. "		       \
+			"errno = %d when expected was %d. (force: %d)",        \
+			_test.testname, _gotret, _test.exp_ret, _goterr,       \
+			_test.exp_errno, _test.force);			       \
+		return;							       \
+	} while (0)
+
+#define failed_unexpec(_test, _gotret, _goterr) 			       \
+	do {								       \
+		tst_res(TFAIL, "membarrier(2): %s failed unexpectedly. "       \
+			"Got ret = %ld with errno %d. (force: %d)",	       \
+			_test.testname, _gotret, _goterr, _test.force);	       \
+		return;							       \
+	} while (0)
+
+#define skipped(_test)							       \
+	do {								       \
+		tst_res(TPASS, "membarrier(2): %s skipped (unsupported)",      \
+			_test.testname);				       \
+		return;							       \
+	} while (0)
+
+#define skipped_fail(_test)						       \
+	do {								       \
+		tst_res(TFAIL, "membarrier(2): %s reported as not supported",  \
+			_test.testname);				       \
+		return;							       \
+	} while (0)
+
+static int sys_membarrier(int cmd, int flags)
+{
+	return tst_syscall(__NR_membarrier, cmd, flags);
+}
+
+static void verify_membarrier(unsigned int i)
+{
+	int ret;
+
+	/* not enabled and not enforced: test is skipped */
+
+	if (!tc[i].enabled && !tc[i].force) {
+
+		if (tc[i].always == 0)
+			skipped(tc[i]);
+
+		skipped_fail(tc[i]);
+	}
+
+	/* iterations: registration needed for some cases */
+
+	if (tc[i].needregister && tc[i].enabled) {
+		ret = sys_membarrier(tc[i].needregister, 0);
+		if (ret < 0) {
+			tst_brk(TBROK, "membarrier(2): %s could not register",
+					tc[i].testname);
+		}
+	}
+
+	TEST(sys_membarrier(tc[i].command, tc[i].flags));
+
+	/* enabled and not enforced: regular expected results only */
+
+	if (tc[i].enabled && !tc[i].force) {
+
+		if (TST_RET >= 0 && tc[i].exp_ret == TST_RET)
+			passed_ok(tc[i]);
+
+		if (TST_RET < 0) {
+			if (tc[i].exp_ret == TST_RET)
+				failed_ok(tc[i]);
+			else
+				failed_not_ok(tc[i], TST_RET, TST_ERR);
+		}
+	}
+
+	/* not enabled and enforced: failure and expected errors */
+
+	if (!tc[i].enabled && tc[i].force) {
+
+		if (TST_RET >= 0)
+			passed_unexpec(tc[i]);
+
+		if (TST_RET < 0) {
+			if (tc[i].force_exp_errno == TST_ERR)
+				failed_ok_unsupported(tc[i]);
+			else
+				failed_unexpec(tc[i], TST_RET, TST_ERR);
+		}
+	}
+
+	/* enabled and enforced: tricky */
+
+	if (tc[i].enabled && tc[i].force) {
+
+		if (TST_RET >= 0) {
+			if (tc[i].exp_ret == TST_RET)
+				passed_ok(tc[i]);
+			else
+				passed_unexpec(tc[i]);
+		}
+
+		if (TST_RET < 0) {
+
+			if (tc[i].exp_ret == TST_RET) {
+
+				if (tc[i].exp_errno == TST_ERR)
+					failed_ok(tc[i]);
+				else
+					failed_unexpec(tc[i], TST_RET, TST_ERR);
+			}
+
+			/* unknown on force failure if enabled and forced */
+			failed_unexpec(tc[i], TST_RET, TST_ERR);
+		}
+	}
+}
+
+static void wrap_verify_membarrier(unsigned int i)
+{
+	pid_t pid;
+
+	/*
+	 * The Linux kernel does not provide a way to unregister the process
+	 * (mm->membarrier_state) intent of being affected by the membarrier(2)
+	 * system call, thus the need of having a wrapper to fork() a child.
+	 */
+
+	pid = SAFE_FORK();
+
+	if (pid)
+		SAFE_WAITPID(pid, NULL, 0);
+	else
+		verify_membarrier(i);
+}
+
+static void setup(void)
+{
+	size_t i;
+	int ret;
+
+	ret = sys_membarrier(MEMBARRIER_CMD_QUERY, 0);
+	if (ret < 0) {
+		if (errno == ENOSYS)
+			tst_brk(TBROK, "membarrier(2): not supported");
+	}
+
+	for (i = 0; i < ARRAY_SIZE(tc); i++) {
+		if ((tc[i].command > 0) && (ret & tc[i].command))
+			tc[i].enabled = 1;
+	}
+
+	/* case 05: commit 70216e18e5 (v4.16-rc1) changed behavior */
+
+	if (tst_kvercmp(4, 16, 0) < 0 && tc[5].enabled == 0)
+		tc[5].force_exp_errno = EINVAL;
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.test = wrap_verify_membarrier,
+	.tcnt = ARRAY_SIZE(tc),
+	.min_kver = "4.3.0",	/* commit: 5b25b13ab0 (sys_membarrier(): ...) */
+	.forks_child = 1,
+};
+
+#else /* HAVE_LINUX_MEMBARRIER_H */
+TST_TEST_TCONF("<linux/membarrier.h> does not exist");
+#endif