[LTP] [PATCH v2 4/8] Add ioctl_pidfd02 test
Andrea Cervesato
andrea.cervesato@suse.de
Fri Jul 4 13:30:42 CEST 2025
From: Andrea Cervesato <andrea.cervesato@suse.com>
Check if the ioctl() function allows retrieval of a child's exit code
using PIDFD_INFO_EXIT from a process that can be isolated or not from
the child.
Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
runtest/syscalls | 1 +
testcases/kernel/syscalls/ioctl/.gitignore | 1 +
testcases/kernel/syscalls/ioctl/ioctl_pidfd02.c | 82 +++++++++++++++++++++++++
3 files changed, 84 insertions(+)
diff --git a/runtest/syscalls b/runtest/syscalls
index 7f6312ce5fa241a778d8dda7f8ee9edd0a8800e6..23f335846663d62a39e6de3a8f6948c1b0acf8a5 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -613,6 +613,7 @@ ioctl_ficlonerange02 ioctl_ficlonerange02
ioctl_fiemap01 ioctl_fiemap01
ioctl_pidfd01 ioctl_pidfd01
+ioctl_pidfd02 ioctl_pidfd02
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 aa952c1a7bae0ae2dbb04de0595f10d508b6759a..1c81c2bed8db952af0c93fb1ce5bfbad82794b60 100644
--- a/testcases/kernel/syscalls/ioctl/.gitignore
+++ b/testcases/kernel/syscalls/ioctl/.gitignore
@@ -30,3 +30,4 @@
/ioctl_ficlonerange02
/ioctl_fiemap01
/ioctl_pidfd01
+/ioctl_pidfd02
diff --git a/testcases/kernel/syscalls/ioctl/ioctl_pidfd02.c b/testcases/kernel/syscalls/ioctl/ioctl_pidfd02.c
new file mode 100644
index 0000000000000000000000000000000000000000..a5a9a561ff676607d68a33ed5572d4c3cdb28f26
--- /dev/null
+++ b/testcases/kernel/syscalls/ioctl/ioctl_pidfd02.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2025 Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * Check if the ioctl() function allows retrieval of a child's exit code
+ * using PIDFD_INFO_EXIT from a process that can be isolated or not from the
+ * child.
+ */
+
+#include "tst_test.h"
+#include "lapi/pidfd.h"
+#include "lapi/sched.h"
+
+static struct tst_clone_args *args;
+static struct pidfd_info *info0, *info1;
+
+static void run(unsigned int isolate)
+{
+ int status;
+ int pidfd = 0;
+ pid_t pid_child;
+
+ memset(args, 0, sizeof(struct tst_clone_args));
+ memset(info0, 0, sizeof(struct pidfd_info));
+ memset(info1, 0, sizeof(struct pidfd_info));
+
+ if (isolate) {
+ args->flags = CLONE_PIDFD | CLONE_NEWUSER | CLONE_NEWPID;
+ args->pidfd = (uint64_t)&pidfd;
+ args->exit_signal = SIGCHLD;
+
+ pid_child = SAFE_CLONE(args);
+ } else {
+ pid_child = SAFE_FORK();
+ }
+
+ if (!pid_child) {
+ TST_CHECKPOINT_WAIT(0);
+ exit(100);
+ }
+
+ if (!isolate)
+ pidfd = SAFE_PIDFD_OPEN(pid_child, 0);
+
+ /* child is not reaped and ioctl() won't provide any exit status info */
+ info0->mask = PIDFD_INFO_EXIT;
+ SAFE_IOCTL(pidfd, PIDFD_GET_INFO, info0);
+ TST_EXP_EQ_LI(info0->mask & PIDFD_INFO_EXIT, 0);
+ TST_EXP_EQ_LI(info0->exit_code, 0);
+
+ TST_CHECKPOINT_WAKE(0);
+
+ SAFE_WAITPID(pid_child, &status, 0);
+
+ /* child is now reaped and ioctl() will provide the exit status */
+ info1->mask = PIDFD_INFO_EXIT;
+ SAFE_IOCTL(pidfd, PIDFD_GET_INFO, info1);
+
+ TST_EXP_EQ_LI(info1->mask & PIDFD_INFO_EXIT, PIDFD_INFO_EXIT);
+ TST_EXP_EQ_LI(WIFEXITED(info1->exit_code), WIFEXITED(status));
+ TST_EXP_EQ_LI(WEXITSTATUS(info1->exit_code), WEXITSTATUS(status));
+
+ TST_EXP_EXPR(info0->exit_code != info1->exit_code,
+ "info0->exit_code (%i) != info1->exit_code (%i)",
+ info0->exit_code, info1->exit_code);
+}
+
+static struct tst_test test = {
+ .test = run,
+ .tcnt = 2,
+ .forks_child = 1,
+ .needs_checkpoints = 1,
+ .min_kver = "6.15",
+ .bufs = (struct tst_buffers []) {
+ {&args, .size = sizeof(*args)},
+ {&info0, .size = sizeof(*info0)},
+ {&info1, .size = sizeof(*info1)},
+ {}
+ }
+};
--
2.50.0
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