Introduce a test case simulating stack corruption across recursive calls. This scenario writes to a local buffer at every recursion depth up to a configured maximum, allowing validation that KStackWatch can detect corruption in nested stack frames.
Signed-off-by: Jinchao Wang <[email protected]> --- mm/kstackwatch/kstackwatch_test.c | 32 ++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/mm/kstackwatch/kstackwatch_test.c b/mm/kstackwatch/kstackwatch_test.c index 1f0d616db7c5..cb216b6ee5d7 100644 --- a/mm/kstackwatch/kstackwatch_test.c +++ b/mm/kstackwatch/kstackwatch_test.c @@ -146,6 +146,30 @@ static void silent_corruption_test(void) silent_corruption_hapless(i); } +/* + * Test Case 3: Recursive Call Corruption + * Check whether KStackWatch can handle corruption in a recursive call + * Write the local variable at every depth + * Configure /proc/kstackwatch to specify the corruption depth + * Verify that the watch is triggered + */ +static void recursive_corruption_test(int depth) +{ + u64 buffer[BUFFER_SIZE]; + + pr_info("KSW: test: recursive call at depth %d\n", depth); + pr_info("KSW: test: buffer 0x%px\n", buffer); + if (depth <= MAX_DEPTH) + recursive_corruption_test(depth + 1); + + buffer[0] = depth; + + /* make sure the compiler do not drop assign action */ + barrier_data(buffer); + + pr_info("KSW: test: returning from depth %d\n", depth); +} + static ssize_t test_proc_write(struct file *file, const char __user *buffer, size_t count, loff_t *pos) { @@ -177,6 +201,11 @@ static ssize_t test_proc_write(struct file *file, const char __user *buffer, pr_info("KSW: test: triggering silent corruption test\n"); silent_corruption_test(); break; + case 3: + pr_info("KSW: test: triggering recursive corruption test\n"); + /* depth start with 0 */ + recursive_corruption_test(0); + break; default: pr_err("KSW: test: Unknown test number %d\n", test_num); return -EINVAL; @@ -198,7 +227,8 @@ static ssize_t test_proc_read(struct file *file, char __user *buffer, "Usage:\n" " echo 'test0' > /proc/kstackwatch_test - Canary write test\n" " echo 'test1' > /proc/kstackwatch_test - Canary overflow test\n" - " echo 'test2' > /proc/kstackwatch_test - Silent corruption test\n"; + " echo 'test2' > /proc/kstackwatch_test - Silent corruption test\n" + " echo 'test3' > /proc/kstackwatch_test - Recursive corruption test\n"; return simple_read_from_buffer(buffer, count, pos, usage, strlen(usage)); -- 2.43.0
