> I was going through try_module_get function in include/linux/module.h file > (2.6.22 stock kernel) - which is like: > > ----- > 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; <---- > } > ---- > > What I understand about the code flow is: > -- module live would return the flag stating that this module can be reference > and is NOT being removed currently. > > 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??. > > Can anyone help me out with this? Any help would be highly appreciated.
Somewhere in module.h you have: #ifdef MODULE #define THIS_MODULE (&__this_module) #else /* !MODULE */ #define THIS_MODULE ((struct module *)0) #endif So this just means, that THIS_MODULE is NULL for compiled in modules and therefore try_module_get(NULL) succeeds. It's not an error case. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/