On Sat, Feb 24, 2018 at 10:06:01PM +0000, Luis R. Rodriguez wrote: > On Sat, Feb 24, 2018 at 11:45:16AM +0300, Dan Carpenter wrote: > > On Sat, Feb 24, 2018 at 02:59:41AM +0000, Luis R. Rodriguez wrote: > > > On Mon, Jan 22, 2018 at 01:27:54PM +0300, Dan Carpenter wrote: > > > > 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. > > > > > > Doh, thanks, yes. Seems worth considering a grammar rule for it. > > > > > > > The other problem is that signed integer overflows like "INT_MAX + 1" are > > > > undefined behavior. > > > > > > Likewise. > > > > > > This seems like another possible generic typo issue. But I would not resolve it > > > the way you did, in this particular case below num_test_devs represents the > > > number of already registered devs, before we increment. So the way to resolve > > > this would be: > > > > > > if (num_test_devs + 1 == INT_MAX) > > > > > > I'll get this upstream, thanks! > > > > There is no issue if num_test_devs is INT_MAX. But capping it at > > INT_MAX - 1 is also fine. > > If num_test_devs is INT_MAX, then doing num_test_devs + 1 overflows > and as you noted that is undefined? If it's INT_MAX we never do "num_test_devs + 1", we return a NULL. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
