Re: [PATCH bpf-next v5 5/7] bpf: lsm: Initialize the BPF LSM hooks

From: Casey Schaufler
Date: Mon Mar 23 2020 - 19:39:44 EST


On 3/23/2020 3:12 PM, Kees Cook wrote:
> On Mon, Mar 23, 2020 at 02:58:18PM -0700, Casey Schaufler wrote:
>> That's not too terrible, I suppose. What would you be thinking for
>> the calls that do use call_int_hook()?
>>
>> rc = call_int_hook(something, something_default, goodnesses);
>>
>> or embedded in the macro:
>>
>> rc = call_int_hook(something, goodnesses);
> Oh yes, good point. The hook call already knows the name, so:
>
> #define call_int_hook(FUNC, ...) ({ \
> int RC = FUNC#_default; \
> ...

That makes the most sense, I think. It's getting a little heavy on
hidden magic, but we do tend to have a pretty good set of eyes watching
when a new hook is proposed. I would expect the changes to call_int_hook()
and its callers should be made when default is added to LSM_HOOK, not
after.