On Thu, 27 Sep 2007 05:19:06 -0000, Shreyansh Jain said:
> -----
> static inline int try_module_get(struct module *module){
> int ret = 1; <--- error case when !module
> if (module) {
> unsigned int cpu = get_cpu();
> if (likely(module_is_live(module)))
> local_inc(&module->ref[cpu].count);
> else
> ret = 0; <--- error case
> put_cpu();
> }
> return ret; <----
> }> 1. In case the module pointer passed is invalid (NULL) this function would > return 1 (error case) > 2. In case the module pointer is OK, and module is currently not being > removed, > reference count would be incremented and 1 returned (non error case) > 3. In case the module pointer is OK, and module reference count can NOT be > increased, 0 would be returned (error case). > > As you can observe from above points, 0 and 1 are returned for error cases. I > am > a little confused and wondering if there is something which I am missing in > this > code??. Go look at the call sites for this function - I bet that most of them, if they check the return code at all, only check for zero or nonzero, because they only *care* about the case that returns zero. Since they already know they're not passing a NULL pointer, they don't worry about that case returning a 1. So there's only two realistic returns - either the module is live or it isn't.
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