[PATCH] lib: interval_tree_test: validate benchmark parameters

[Samuel Moelius <sam.moelius@trailofbits.com>]

The interval tree runtime test accepts module parameters that are later
used as divisors while generating randomized intervals and while
reporting average timings. For example, max_endpoint=1 makes the
generated interval end value zero and the next modulo operation divides
by that zero value.

Reject non-positive counts and require max_endpoint to provide at least
one non-zero generated endpoint before the test allocates state or
starts the benchmark.

Assisted-by: Codex:gpt-5.5-cyber-preview
Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>
---
 lib/interval_tree_test.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/lib/interval_tree_test.c b/lib/interval_tree_test.c
index 16200feacbf3..58f6f3a307f4 100644
--- a/lib/interval_tree_test.c
+++ b/lib/interval_tree_test.c
@@ -311,6 +311,27 @@ static inline int span_iteration_check(void) {return 0; }
 
 static int interval_tree_test_init(void)
 {
+	if (nnodes <= 0) {
+		pr_warn("nnodes must be positive\n");
+		return -EINVAL;
+	}
+	if (nsearches <= 0) {
+		pr_warn("nsearches must be positive\n");
+		return -EINVAL;
+	}
+	if (perf_loops <= 0) {
+		pr_warn("perf_loops must be positive\n");
+		return -EINVAL;
+	}
+	if (search_loops <= 0) {
+		pr_warn("search_loops must be positive\n");
+		return -EINVAL;
+	}
+	if (max_endpoint < 2) {
+		pr_warn("max_endpoint must be at least 2\n");
+		return -EINVAL;
+	}
+
 	nodes = kmalloc_objs(struct interval_tree_node, nnodes);
 	if (!nodes)
 		return -ENOMEM;
-- 
2.43.0