As reported by Dan the parentheses is in the wrong place, and since unlikely() call returns either 0 or 1 it's never less than zero. The second issue is that signed integer overflows like "INT_MAX + 1" are undefined behavior.
Since num_test_devs represents the number of devices, we want to stop prior to hitting the max, and not rely on the wrap arround at all. So just cap at num_test_devs + 1, prior to assigning a new device. Reported-by: Dan Carpenter <[email protected]> Fixes: d9c6a72d6fa2 ("kmod: add test driver to stress test the module loader") Signed-off-by: Luis R. Rodriguez <[email protected]> --- lib/test_kmod.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/test_kmod.c b/lib/test_kmod.c index e372b97eee13..0e5b7a61460b 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(®_dev_mutex); /* int should suffice for number of devices, test for wrap */ - if (unlikely(num_test_devs + 1) < 0) { + if (num_test_devs + 1 == INT_MAX) { pr_err("reached limit of number of test devices\n"); goto out; } -- 2.16.2
