Re: [PATCH] Add private_function for private functions within glibc [BZ #21598]

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

On Thu, Aug 10, 2017 at 5:49 AM, Florian Weimer <fweimer@redhat.com> wrote:
> On 08/10/2017 02:44 PM, H.J. Lu wrote:
>
>> It is OK to use __attribute__ ((regparm (3))) with CET as long as the
>> function is hidden.  We need to at least keep __attribute__ ((regparm (1)))
>> on ___tls_get_addr since it is the part of TLS ABI and we may have to
>> support  __attribute__ ((regparm (3))) for lazy binding when CET is disabled
>> forever.  Remove it from glibc doesn't buy us much.
>
> It buys us peace of mind for those of us who do not work on i386 because
> internal_function mismatches are a constant source of i386 build
> failures.  I want to get rid of it because I think its presence is a
> poor trade-off for the project as a whole.
>

That is fine with me then.

FWIW, last time when I tried it, I gave up after many segfaults :-(.
The list of places I remembered:

1. _dl_init.
2. _dl_fixup
3. TLS lookup functions.

There may be more.


-- 
H.J.