[LTP] [PATCH v3] sched_setscheduler04.c: Test SCHED_RESET_ON_FORK

[Wei Gao]

Signed-off-by: Federico Bonfiglio <federico.bonfiglio@protonmail.ch>
Signed-off-by: Wei Gao <wegao@suse.com>
---
 include/lapi/capability.h                     |  4 +
 runtest/syscalls                              |  1 +
 .../syscalls/sched_setscheduler/.gitignore    |  1 +
 .../sched_setscheduler/sched_setscheduler04.c | 78 +++++++++++++++++++
 4 files changed, 84 insertions(+)
 create mode 100644 testcases/kernel/syscalls/sched_setscheduler/sched_setscheduler04.c

diff --git a/include/lapi/capability.h b/include/lapi/capability.h
index 17ec107b1..2b593797c 100644
--- a/include/lapi/capability.h
+++ b/include/lapi/capability.h
@@ -36,6 +36,10 @@
 # define CAP_SYS_ADMIN        21
 #endif
 
+#ifndef CAP_SYS_NICE
+# define CAP_SYS_NICE         23
+#endif
+
 #ifndef CAP_SYS_TIME
 # define CAP_SYS_TIME         25
 #endif
diff --git a/runtest/syscalls b/runtest/syscalls
index 04b758fd9..b86188013 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1228,6 +1228,7 @@ 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/sched_setscheduler04.c b/testcases/kernel/syscalls/sched_setscheduler/sched_setscheduler04.c
new file mode 100644
index 000000000..828d1ec09
--- /dev/null
+++ b/testcases/kernel/syscalls/sched_setscheduler/sched_setscheduler04.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022 Federico Bonfiglio <federico.bonfiglio@protonmail.ch>
+ */
+
+/*
+ * [Description]
+ *
+ * Testcases that test if sched_setscheduler with flag
+ * SCHED_RESET_ON_FORK restores children policy to
+ * SCHED_NORMAL.
+ *
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <sched.h>
+#include <linux/sched.h>
+
+#include "tst_test.h"
+#include "tst_sched.h"
+
+struct test_case_t {
+	int policy;
+	char *desc;
+};
+
+static struct test_case_t cases[] = {
+	{
+		.policy = SCHED_FIFO,
+		.desc = "SCHED_FIFO"
+	},
+	{
+		.policy = SCHED_RR,
+		.desc = "SCHED_RR"
+	}
+};
+
+static void test_reset_on_fork(unsigned int i)
+{
+	struct sched_variant *tv = &sched_variants[tst_variant];
+	struct test_case_t *tc = &cases[i];
+
+	tst_res(TINFO, "Testing %s variant %s policy", tv->desc, tc->desc);
+
+	struct sched_param param = { .sched_priority = 10 };
+
+	tv->sched_setscheduler(getpid(), tc->policy | SCHED_RESET_ON_FORK, &param);
+
+	pid_t pid = SAFE_FORK();
+
+	if (pid) {
+		if (sched_getscheduler(pid) == SCHED_NORMAL)
+			tst_res(TPASS, "Policy reset to SCHED_NORMAL");
+		else
+			tst_res(TFAIL, "Policy NOT reset to SCHED_NORMAL");
+
+		sched_getparam(pid, &param);
+
+		/* kernel will return sched_priority 0 if task is not RT Policy */
+		if (param.sched_priority == 0)
+			tst_res(TPASS, "Priority set to 0");
+		else
+			tst_res(TFAIL, "Priority not set to 0");
+	}
+}
+
+static struct tst_test test = {
+	.forks_child = 1,
+	.caps = (struct tst_cap[]) {
+		TST_CAP(TST_CAP_REQ, CAP_SYS_NICE),
+		{}
+	},
+	.test_variants = ARRAY_SIZE(sched_variants),
+	.tcnt = ARRAY_SIZE(cases),
+	.test = test_reset_on_fork,
+};
-- 
2.35.3