[LTP] [PATCH 1/2] syscalls/pidfd_open: Simplify code

[Yang Xu]

1) make use of TST_EXP_FAIL2 or TST_EXP_PID_SILENT macros
2) remove min_kver check and use pidfd_open_supported()
3) Add docparse formatting

Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
---
 include/lapi/pidfd_open.h                     |  8 +++--
 .../kernel/syscalls/pidfd_open/pidfd_open01.c | 22 +++++++-----
 .../kernel/syscalls/pidfd_open/pidfd_open02.c | 34 +++++++------------
 .../kernel/syscalls/pidfd_open/pidfd_open03.c | 16 ++++++---
 4 files changed, 44 insertions(+), 36 deletions(-)

diff --git a/include/lapi/pidfd_open.h b/include/lapi/pidfd_open.h
index 9806c73d4..5cf10933e 100644
--- a/include/lapi/pidfd_open.h
+++ b/include/lapi/pidfd_open.h
@@ -9,11 +9,15 @@
 
 #include <sys/syscall.h>
 #include <sys/types.h>
-
 #include "lapi/syscalls.h"
-
 #include "config.h"
 
+static inline void pidfd_open_supported(void)
+{
+	/* allow the tests to fail early */
+	tst_syscall(__NR_pidfd_open);
+}
+
 #ifndef HAVE_PIDFD_OPEN
 static inline int pidfd_open(pid_t pid, unsigned int flags)
 {
diff --git a/testcases/kernel/syscalls/pidfd_open/pidfd_open01.c b/testcases/kernel/syscalls/pidfd_open/pidfd_open01.c
index f40e9b624..ed9b82637 100644
--- a/testcases/kernel/syscalls/pidfd_open/pidfd_open01.c
+++ b/testcases/kernel/syscalls/pidfd_open/pidfd_open01.c
@@ -1,11 +1,15 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) 2020 Viresh Kumar <viresh.kumar@linaro.org>
+ */
+
+/*\
+ * [Description]
  *
- * Description:
  * Basic pidfd_open() test:
- * 1) Fetch the PID of the current process and try to get its file descriptor.
- * 2) Check that the close-on-exec flag is set on the file descriptor.
+ *
+ * - Fetch the PID of the current process and try to get its file descriptor.
+ * - Check that the close-on-exec flag is set on the file descriptor.
  */
 
 #include <unistd.h>
@@ -17,10 +21,7 @@ static void run(void)
 {
 	int flag;
 
-	TEST(pidfd_open(getpid(), 0));
-
-	if (TST_RET == -1)
-		tst_brk(TFAIL | TTERRNO, "pidfd_open(getpid(), 0) failed");
+	TST_EXP_PID_SILENT(pidfd_open(getpid(), 0), "pidfd_open(getpid(), 0)");
 
 	flag = fcntl(TST_RET, F_GETFD);
 
@@ -35,7 +36,12 @@ static void run(void)
 	tst_res(TPASS, "pidfd_open(getpid(), 0) passed");
 }
 
+static void setup(void)
+{
+	pidfd_open_supported();
+}
+
 static struct tst_test test = {
-	.min_kver = "5.3",
+	.setup = setup,
 	.test_all = run,
 };
diff --git a/testcases/kernel/syscalls/pidfd_open/pidfd_open02.c b/testcases/kernel/syscalls/pidfd_open/pidfd_open02.c
index dc86cae7a..93a61a51d 100644
--- a/testcases/kernel/syscalls/pidfd_open/pidfd_open02.c
+++ b/testcases/kernel/syscalls/pidfd_open/pidfd_open02.c
@@ -1,14 +1,21 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) 2020 Viresh Kumar <viresh.kumar@linaro.org>
+ */
+
+/*\
+ * [Description]
+ *
+ * Tests basic error handling of the pidfd_open syscall.
  *
- * Description:
- * Basic pidfd_open() test to test invalid arguments.
+ * - ESRCH the process specified by pid does not exist
+ * - EINVAL pid is not valid
+ * - EINVAL flags is not valid
  */
 #include "tst_test.h"
 #include "lapi/pidfd_open.h"
 
-pid_t expired_pid, my_pid, invalid_pid = -1;
+static pid_t expired_pid, my_pid, invalid_pid = -1;
 
 static struct tcase {
 	char *name;
@@ -23,6 +30,7 @@ static struct tcase {
 
 static void setup(void)
 {
+	pidfd_open_supported();
 	expired_pid = tst_get_unused_pid();
 	my_pid = getpid();
 }
@@ -31,27 +39,11 @@ static void run(unsigned int n)
 {
 	struct tcase *tc = &tcases[n];
 
-	TEST(pidfd_open(*tc->pid, tc->flags));
-
-	if (TST_RET != -1) {
-		SAFE_CLOSE(TST_RET);
-		tst_res(TFAIL, "%s: pidfd_open succeeded unexpectedly (index: %d)",
-			tc->name, n);
-		return;
-	}
-
-	if (tc->exp_errno != TST_ERR) {
-		tst_res(TFAIL | TTERRNO, "%s: pidfd_open() should fail with %s",
-			tc->name, tst_strerrno(tc->exp_errno));
-		return;
-	}
-
-	tst_res(TPASS | TTERRNO, "%s: pidfd_open() failed as expected",
-		tc->name);
+	TST_EXP_FAIL2(pidfd_open(*tc->pid, tc->flags), tc->exp_errno,
+			"pidfd_open with %s", tc->name);
 }
 
 static struct tst_test test = {
-	.min_kver = "5.3",
 	.tcnt = ARRAY_SIZE(tcases),
 	.test = run,
 	.setup = setup,
diff --git a/testcases/kernel/syscalls/pidfd_open/pidfd_open03.c b/testcases/kernel/syscalls/pidfd_open/pidfd_open03.c
index 48470e5e1..f41afa2fc 100644
--- a/testcases/kernel/syscalls/pidfd_open/pidfd_open03.c
+++ b/testcases/kernel/syscalls/pidfd_open/pidfd_open03.c
@@ -1,8 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) 2020 Viresh Kumar <viresh.kumar@linaro.org>
+ */
+
+/*\
+ * [Description]
  *
- * Description:
  * This program opens the PID file descriptor of the child process created with
  * fork(). It then uses poll to monitor the file descriptor for process exit, as
  * indicated by an EPOLLIN event.
@@ -27,11 +30,9 @@ static void run(void)
 		exit(EXIT_SUCCESS);
 	}
 
-	TEST(pidfd_open(pid, 0));
+	TST_EXP_PID_SILENT(pidfd_open(pid, 0), "pidfd_open(%d, 0)", pid);
 
 	fd = TST_RET;
-	if (fd == -1)
-		tst_brk(TFAIL | TTERRNO, "pidfd_open() failed");
 
 	TST_CHECKPOINT_WAKE(0);
 
@@ -49,8 +50,13 @@ static void run(void)
 		tst_res(TPASS, "pidfd_open() passed");
 }
 
+static void setup(void)
+{
+	pidfd_open_supported();
+}
+
 static struct tst_test test = {
-	.min_kver = "5.3",
+	.setup = setup,
 	.test_all = run,
 	.forks_child = 1,
 	.needs_checkpoints = 1,
-- 
2.23.0