[LTP] [PATCH v2] syscalls/sched_setscheduler04: new test for sched_setscheduler()

[Zhao Gongyi]

Verify that the scheduling policy and parameters are in fact per-thread
attributes on Linux:
1. Specifying pid as 0 will operate on the attributes of the calling thread
2. The value returned from a call to gettid(2) can be passed in the argument
   pid.
3. Passing the value returned from a call to getpid(2) will operate on the
   attributes of the main thread of the  thread  group

Signed-off-by: Zhao Gongyi <zhaogongyi@huawei.com>
---
 runtest/syscalls                              |   1 +
 .../syscalls/sched_setscheduler/.gitignore    |   1 +
 .../syscalls/sched_setscheduler/Makefile      |   2 +
 .../sched_setscheduler/sched_setscheduler04.c | 101 ++++++++++++++++++
 4 files changed, 105 insertions(+)
 create mode 100644 testcases/kernel/syscalls/sched_setscheduler/sched_setscheduler04.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 3dc6fa397..ff516af3d 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1204,6 +1204,7 @@ sched_getscheduler02 sched_getscheduler02
 sched_setscheduler01 sched_setscheduler01
 sched_setscheduler02 sched_setscheduler02
 sched_setscheduler03 sched_setscheduler03
+sched_setscheduler04 sched_setscheduler04

 sched_yield01 sched_yield01

diff --git a/testcases/kernel/syscalls/sched_setscheduler/.gitignore b/testcases/kernel/syscalls/sched_setscheduler/.gitignore
index aa8ad9695..1b8860d2c 100644
--- a/testcases/kernel/syscalls/sched_setscheduler/.gitignore
+++ b/testcases/kernel/syscalls/sched_setscheduler/.gitignore
@@ -1,3 +1,4 @@
 /sched_setscheduler01
 /sched_setscheduler02
 /sched_setscheduler03
+/sched_setscheduler04
diff --git a/testcases/kernel/syscalls/sched_setscheduler/Makefile b/testcases/kernel/syscalls/sched_setscheduler/Makefile
index 044619fb8..e3d54e33e 100644
--- a/testcases/kernel/syscalls/sched_setscheduler/Makefile
+++ b/testcases/kernel/syscalls/sched_setscheduler/Makefile
@@ -3,6 +3,8 @@

 top_srcdir		?= ../../../..

+sched_setscheduler04: CFLAGS += -pthread
+
 include $(top_srcdir)/include/mk/testcases.mk

 include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/kernel/syscalls/sched_setscheduler/sched_setscheduler04.c b/testcases/kernel/syscalls/sched_setscheduler/sched_setscheduler04.c
new file mode 100644
index 000000000..38f5750ba
--- /dev/null
+++ b/testcases/kernel/syscalls/sched_setscheduler/sched_setscheduler04.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright(c) 2022 Huawei Technologies Co., Ltd
+ * Author: Zhao Gongyi <zhaogongyi@huawei.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * Verify that the scheduling policy and parameters are in fact per-thread
+ * attributes on Linux:
+ * 1. Specifying pid as 0 will operate on the attributes of the calling thread.
+ * 2. The value returned from a call to gettid(2) can be passed in the argument
+ *    pid.
+ * 3. Passing the value returned from a call to getpid(2) will operate on the
+ *    attributes of the main thread of the  thread  group.
+ */
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+#include "tst_safe_pthread.h"
+#include <pthread.h>
+#include <linux/capability.h>
+
+static struct sched_param param;
+static volatile int sched_prio;
+static pid_t pid;
+
+#define ORG_POLICY SCHED_OTHER
+#define EXP_POLICY SCHED_FIFO
+
+static void verify_sched_setscheduler(pid_t tid)
+{
+	int new_policy;
+	pid_t threadid = tst_syscall(__NR_gettid);
+
+	tst_res(TINFO, "Setting of tid: %d", threadid);
+
+	param.sched_priority = sched_prio;
+	if (sched_setscheduler(tid, EXP_POLICY, &param)) {
+		tst_brk(TBROK | TERRNO,
+			"sched_setscheduler(%d, %d, ...) failed",
+			tid, EXP_POLICY);
+	}
+
+	tst_res(TINFO, "Getting and checking of tid: %d", threadid);
+
+	new_policy = sched_getscheduler(threadid);
+	if (new_policy < 0)
+		tst_brk(TBROK | TERRNO, "sched_getscheduler() failed");
+
+	if (sched_getparam(threadid, &param) != 0)
+		tst_brk(TBROK | TERRNO, "sched_getparam() failed");
+
+	TST_EXP_EQ_LI(param.sched_priority, sched_prio);
+	TST_EXP_EQ_LI(new_policy, EXP_POLICY);
+}
+
+static void *thread_func(LTP_ATTRIBUTE_UNUSED void *arg)
+{
+	pid_t threadid = tst_syscall(__NR_gettid);
+
+	sched_prio++;
+	verify_sched_setscheduler(0);
+	sched_prio++;
+	verify_sched_setscheduler(threadid);
+
+	return NULL;
+}
+
+static void run(void)
+{
+	pthread_t tid;
+
+	sched_prio = sched_get_priority_min(EXP_POLICY);
+
+	sched_prio++;
+	verify_sched_setscheduler(pid);
+
+	SAFE_PTHREAD_CREATE(&tid, NULL, thread_func, NULL);
+	SAFE_PTHREAD_JOIN(tid, NULL);
+}
+
+static void setup(void)
+{
+	pid = getpid();
+
+	if (sched_setscheduler(pid, ORG_POLICY, &param)) {
+		tst_brk(TBROK | TERRNO,
+			"sched_setscheduler(%d, %d, ...) failed",
+			pid, ORG_POLICY);
+	}
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.test_all = run,
+	.caps = (struct tst_cap[]) {
+		TST_CAP(TST_CAP_REQ, CAP_SYS_NICE),
+		{}
+	}
+};
--
2.17.1