[LTP] [PATCH v2 5/8] Add ioctl_pidfd03 test

[Andrea Cervesato]

From: Andrea Cervesato <andrea.cervesato@suse.com>

Verify that ioctl() returns ESRCH when a process attempts to access
the exit status of an isolated child using `PIDFD_GET_INFO` and
`PIDFD_INFO_EXIT` is not defined in `struct pidfd_info`.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
 runtest/syscalls                                |  1 +
 testcases/kernel/syscalls/ioctl/.gitignore      |  1 +
 testcases/kernel/syscalls/ioctl/ioctl_pidfd03.c | 57 +++++++++++++++++++++++++
 3 files changed, 59 insertions(+)

diff --git a/runtest/syscalls b/runtest/syscalls
index 23f335846663d62a39e6de3a8f6948c1b0acf8a5..8eec613a941a83b1fed25f96cdce617da0b0ef34 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -614,6 +614,7 @@ ioctl_fiemap01 ioctl_fiemap01
 
 ioctl_pidfd01 ioctl_pidfd01
 ioctl_pidfd02 ioctl_pidfd02
+ioctl_pidfd03 ioctl_pidfd03
 
 inotify_init1_01 inotify_init1_01
 inotify_init1_02 inotify_init1_02
diff --git a/testcases/kernel/syscalls/ioctl/.gitignore b/testcases/kernel/syscalls/ioctl/.gitignore
index 1c81c2bed8db952af0c93fb1ce5bfbad82794b60..08387dc8f2bc43f8f3a75264841da4beee28bfac 100644
--- a/testcases/kernel/syscalls/ioctl/.gitignore
+++ b/testcases/kernel/syscalls/ioctl/.gitignore
@@ -31,3 +31,4 @@
 /ioctl_fiemap01
 /ioctl_pidfd01
 /ioctl_pidfd02
+/ioctl_pidfd03
diff --git a/testcases/kernel/syscalls/ioctl/ioctl_pidfd03.c b/testcases/kernel/syscalls/ioctl/ioctl_pidfd03.c
new file mode 100644
index 0000000000000000000000000000000000000000..17cc9eb1bf60024a78e2be9bf15ae186a987b358
--- /dev/null
+++ b/testcases/kernel/syscalls/ioctl/ioctl_pidfd03.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2025 Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * Verify that ioctl() returns ESRCH when a process attempts to access the
+ * exit status of an isolated child using `PIDFD_GET_INFO` and
+ * `PIDFD_INFO_EXIT` is not defined in `struct pidfd_info`.
+ */
+
+#include "tst_test.h"
+#include "lapi/pidfd.h"
+#include "lapi/sched.h"
+
+static struct tst_clone_args *args;
+static struct pidfd_info *info;
+
+static void run(void)
+{
+	int status;
+	int pidfd = 0;
+	pid_t pid_child;
+
+	memset(args, 0, sizeof(struct tst_clone_args));
+
+	args->flags = CLONE_PIDFD | CLONE_NEWUSER | CLONE_NEWPID;
+	args->pidfd = (uint64_t)&pidfd;
+	args->exit_signal = SIGCHLD;
+
+	pid_child = SAFE_CLONE(args);
+	if (!pid_child)
+		exit(100);
+
+	info->mask = 0;
+
+	/* child is not reaped, so ioctl() will pass */
+	SAFE_IOCTL(pidfd, PIDFD_GET_INFO, info);
+	TST_EXP_EQ_LI(info->mask & PIDFD_INFO_EXIT, 0);
+
+	SAFE_WAITPID(pid_child, &status, 0);
+
+	/* child is now reaped, so we get ESRCH */
+	TST_EXP_FAIL(ioctl(pidfd, PIDFD_GET_INFO, info), ESRCH);
+	TST_EXP_EQ_LI(info->mask & PIDFD_INFO_EXIT, 0);
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	.forks_child = 1,
+	.min_kver = "6.15",
+	.bufs = (struct tst_buffers []) {
+		{&args, .size = sizeof(*args)},
+		{&info, .size = sizeof(*info)},
+		{}
+	}
+};

-- 
2.50.0