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>
This commit is contained in:
Samuel Moelius 2026-06-09 00:54:47 +00:00 committed by Andrew Morton
parent 22920541c3
commit c1fff9794a

View File

@ -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;