Re: [RESEND PATCH v9] Mutex: Add pthread mutex tunables

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

On Thu, Nov 29, 2018 at 7:07 PM kemi <kemi.wang@intel.com> wrote:
>
>
>
> On 2018/11/30 上午10:42, kemi wrote:
> >
> >
> > On 2018/11/29 下午10:41, Florian Weimer wrote:
> >> * Kemi Wang:
> >>
> >>> +#       SXID_ERASE: (default) Don't read for AT_SECURE binaries and
> >>> +#                   removed so that child processes can't read it.
> >>
> >> I think this will not work as intended for libpthread tunables because
> >> if libpthread is not linked in, no code in nptl/nptl-init.c ever runs.
> >>
> >
> > this tunable is for pthread mutex. If the libpthread is not linked in,
> > it seems reasonable that we can't use this tunables.
> >
> > Why do we need to move to elf/dl-tunables.list and do some tricks?
> >
>
> Or you are talking something on pthread mutex shared within multiple processes?
> (pthread_mutexattr_setpshared(mattr,pshared))
>
> In this case, libpthread may not need, and we still hope pthread mutex tunable
> works in this case?
>
> >> I think we need to move the tunable to elf/dl-tunables.list, parse it
> >> there, and communicate the result to libpthread, possibly via
> >> _rtld_global_ro.

What is the usage for that?  Sure, if libpread isn't linked in, these
tunables will
have the default values, which aren't used by anyone.

-- 
H.J.