[PATCH] lib/test_kmod: Fix an integer overflow test

From: Dan Carpenter
Date: Mon Jan 22 2018 - 05:38:12 EST


The main problem is that the parentheses are in the wrong place and the
unlikely() call returns either 0 or 1 so it's never less than zero. The
other problem is that signed integer overflows like "INT_MAX + 1" are
undefined behavior.

Fixes: d9c6a72d6fa2 ("kmod: add test driver to stress test the module loader")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

diff --git a/lib/test_kmod.c b/lib/test_kmod.c
index e372b97eee13..30fd6d9e5361 100644
--- a/lib/test_kmod.c
+++ b/lib/test_kmod.c
@@ -1141,7 +1141,7 @@ static struct kmod_test_device *register_test_dev_kmod(void)
mutex_lock(&reg_dev_mutex);

/* int should suffice for number of devices, test for wrap */
- if (unlikely(num_test_devs + 1) < 0) {
+ if (num_test_devs == INT_MAX) {
pr_err("reached limit of number of test devices\n");
goto out;
}