On Sun, 16 Nov 2014, SF Markus Elfring wrote: > >> diff --git a/kernel/kprobes.c b/kernel/kprobes.c > >> index 3995f54..f1e7d45 100644 > >> --- a/kernel/kprobes.c > >> +++ b/kernel/kprobes.c > >> @@ -1527,8 +1527,7 @@ int register_kprobe(struct kprobe *p) > >> out: > >> mutex_unlock(&kprobe_mutex); > >> > >> - if (probed_mod) > >> - module_put(probed_mod); > >> + module_put(probed_mod); > > > > There is an out label, so please check whether the labels could not be > > better positioned to avoid calling module_put when it is not needed. > > I do not see refactoring opportunities around jump labels in this use case > for the implementation of the register_kprobe() function so far because > the mutex_unlock() function must be called. > Would you like to suggest any other source code fine-tuning?
OK. I don't think that removing the if is a good choice in this case. The code ret = check_kprobe_address_safe(p, &probed_mod); is unusual, in that it can fail to do anything in two ways. One is by setting ret, on detecting an error, and the other is by returning 0 but still putting a NULL value in probed_mod when there is nothing to do. Thus, in the successful execution of the rest of the function, a probed module might or might not exist. The if around the module_put is helpful to the reader to understand that this possibility exists. julia -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
