[PATCH v2] malloc: Remove malloc hooks (Bug 23328)

[Florian Weimer]

* DJ Delorie:

> Florian Weimer <fw@deneb.enyo.de> writes:
>>> +  void *(*hook) (size_t, const void *)
>>> +    = atomic_forced_read (__glibc_malloc_hook);
>>> +  if (__builtin_expect (hook != NULL, 0))
>>> +    return (*hook) (sz, RETURN_ADDRESS (0));
>>
>> Should this use atomic_load_relaxed instead?
>
> It's a copy of what's in malloc/malloc.c

Is supected as much.  Oh well.

>>> +  HOOK (malloc, NULL);
>>
>> I think you can simplify HOOK considerably if you always initialize
>> all function pointers.  Then you don't need to use atomics there
>> because pthread_create always initializes malloc before creating new
>> threads.
>
> I tried that, but you end up being just as complicated due to having to
> check for "set to dummy hooks", plus implementing the dummy hooks,
> plus... etc.  It turned out to not be worth the effort, even once I got
> it working properly (bootstrapping an interposed malloc is not trivial).

Dummy hooks?  I meant to initialize not the hooks, but the next_*
variables.