From: Samuel Moelius <sam.moelius@trailofbits.com>
Date: Tue, 9 Jun 2026 00:54:47 +0000 (+0000)
Subject: lib: interval_tree_test: validate benchmark parameters
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=c1fff9794a165b6b64ae4ad9b54c00bc94e7daed;p=thirdparty%2Fkernel%2Flinux.git

lib: interval_tree_test: validate benchmark parameters

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.

[akpm@linux-foundation.org: include printk.h for pr_warn()]
Assisted-by: Codex:gpt-5.5-cyber-preview
Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>
Link: https://lore.kernel.org/20260609005446.1241288.1525a5964698.interval-tree-test-small-max-endpoint-div0@trailofbits.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/lib/interval_tree_test.c b/lib/interval_tree_test.c
index 16200feacbf3..eba2d3e28980 100644
--- a/lib/interval_tree_test.c
+++ b/lib/interval_tree_test.c
@@ -4,6 +4,7 @@
 #include <linux/interval_tree.h>
 #include <linux/prandom.h>
 #include <linux/slab.h>
+#include <linux/printk.h>
 #include <asm/timex.h>
 #include <linux/bitmap.h>
 #include <linux/maple_tree.h>
@@ -311,6 +312,27 @@ 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;