[LTP] [PATCH] syscalls: chdir02: Add test for valid buffer lenghts

[Cyril Hrubis]

This test tests all buffer lenghts shorter than PATH_MAX and expect the
chdir() syscall to succeed.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
---
 runtest/syscalls                           |  1 +
 testcases/kernel/syscalls/chdir/.gitignore |  1 +
 testcases/kernel/syscalls/chdir/chdir02.c  | 38 ++++++++++++++++++++++
 3 files changed, 40 insertions(+)
 create mode 100644 testcases/kernel/syscalls/chdir/chdir02.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 05bb3ceb1..2f629e4e4 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -68,6 +68,7 @@ cachestat03 cachestat03
 cachestat04 cachestat04
 
 chdir01 chdir01
+chdir02 chdir02
 chdir04 chdir04
 
 chmod01 chmod01
diff --git a/testcases/kernel/syscalls/chdir/.gitignore b/testcases/kernel/syscalls/chdir/.gitignore
index 1b15eb6b9..3475c5e54 100644
--- a/testcases/kernel/syscalls/chdir/.gitignore
+++ b/testcases/kernel/syscalls/chdir/.gitignore
@@ -1,2 +1,3 @@
 /chdir01
+/chdir02
 /chdir04
diff --git a/testcases/kernel/syscalls/chdir/chdir02.c b/testcases/kernel/syscalls/chdir/chdir02.c
new file mode 100644
index 000000000..fc1f80136
--- /dev/null
+++ b/testcases/kernel/syscalls/chdir/chdir02.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2026 Cyril Hrubis <chrubis@suse.cz>
+ */
+
+/*\
+ * Tests that all paths shorter than PATH_MAX work fine.
+ */
+
+#include "tst_test.h"
+
+static char *path;
+
+static void verify_chdir(void)
+{
+	int i, fails = 0;
+
+	memset(path, 0, PATH_MAX);
+
+	for (i = 1; i < PATH_MAX; i++) {
+		memset(path, '/', i);
+
+		TST_EXP_PASS_SILENT(chdir(path), "chdir('/' * %i)", i);
+
+		fails += !TST_PASS;
+	}
+
+	if (!fails)
+		tst_res(TPASS, "Path lenghts <1,%i> worked correctly", PATH_MAX);
+}
+
+static struct tst_test test = {
+	.test_all = verify_chdir,
+	.bufs = (struct tst_buffers []) {
+		{&path, .size = PATH_MAX},
+		{}
+	}
+};
-- 
2.52.0