[PATCH v8 23/27] mm/ksw: add recursive depth test
From: Jinchao Wang <hidden>
Date: 2025-11-10 16:38:25
Also in:
linux-doc, linux-mm, linux-perf-users, lkml, llvm, workflows
Subsystem:
memory management, the rest · Maintainers:
Andrew Morton, Linus Torvalds
Introduce a test that performs stack writes in recursive calls to exercise stack watch at a specific recursion depth. Signed-off-by: Jinchao Wang <redacted> --- mm/kstackwatch/test.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/mm/kstackwatch/test.c b/mm/kstackwatch/test.c
index b3f363d9e1e8..1d196f72faba 100644
--- a/mm/kstackwatch/test.c
+++ b/mm/kstackwatch/test.c@@ -17,6 +17,7 @@ static struct dentry *test_file; #define BUFFER_SIZE 32 +#define MAX_DEPTH 6 static void test_watch_fire(void) {
@@ -48,6 +49,21 @@ static void test_canary_overflow(void) pr_info("exit of %s\n", __func__); } +static void test_recursive_depth(int depth) +{ + u64 buffer[BUFFER_SIZE]; + + pr_info("entry of %s depth:%d\n", __func__, depth); + + if (depth < MAX_DEPTH) + test_recursive_depth(depth + 1); + + buffer[0] = depth; + barrier_data(buffer); + + pr_info("exit of %s depth:%d\n", __func__, depth); +} + static ssize_t test_dbgfs_write(struct file *file, const char __user *buffer, size_t count, loff_t *pos) {
@@ -73,6 +89,9 @@ static ssize_t test_dbgfs_write(struct file *file, const char __user *buffer, case 1: test_canary_overflow(); break; + case 2: + test_recursive_depth(0); + break; default: pr_err("Unknown test number %d\n", test_num); return -EINVAL;
@@ -94,7 +113,8 @@ static ssize_t test_dbgfs_read(struct file *file, char __user *buffer, "Usage:\n" "echo test{i} > /sys/kernel/debug/kstackwatch/test\n" " test0 - test watch fire\n" - " test1 - test canary overflow\n"; + " test1 - test canary overflow\n" + " test2 - test recursive func\n"; return simple_read_from_buffer(buffer, count, ppos, usage, strlen(usage));
--
2.43.0