Re: RFC: ABI support for special memory area

["H.J. Lu" <hjl.tools@gmail.com>]

On Mon, Mar 20, 2017 at 7:57 AM, Florian Weimer <fweimer@redhat.com> wrote:
> On 03/16/2017 07:22 PM, H.J. Lu wrote:
>
>>> If the latter, why can't you use the existing ELF constructor mechanism
>>> for
>>> this?  As far as I understand it, the call to __gnu_mbind_setup would
>>> just
>>> happen before the constructor calls.
>>
>>
>> That is correct.  The issue is to access the ELF segment header for each
>> loaded object only once.  There is no good way to get this info from
>> constructor.
>
>
> I think you can get the data in a pretty straightforward manner using
> dlinfo.

dlinfo is used to info from application.  I don't see how it can be used
here.

> I expect that libraries such as bdwgc might want to use the
> __gnu_mbind_setup callback as well, just to register freshly loaded shared

Did you mean to mark pieces of memory garbage collectible? I guess it may
work.

> objects and their data sections.  Can we make this work for multiple users?
>

What did you mean by "multiple users"?  My proposal targets process memory
address space.  It doesn't forbid sharing memory addresses among different
processes.

-- 
H.J.