RE: [PATCH 3/N, MPX, x86_64] Intel MPX support in glibc for x86_64

["Zamyatin, Igor" <igor dot zamyatin at intel dot com>]

> -----Original Message-----
> From: H.J. Lu [mailto:hjl.tools@gmail.com]
> Sent: Wednesday, April 16, 2014 7:53 PM
> To: Zamyatin, Igor
> Cc: libc-alpha@sourceware.org
> Subject: Re: [PATCH 3/N, MPX, x86_64] Intel MPX support in glibc for x86_64
> 
> On Wed, Mar 19, 2014 at 2:13 PM, Zamyatin, Igor <igor.zamyatin@intel.com>
> wrote:
> > Hi All!
> >
> > Attached patch concludes (see the beginning here -
> http://sourceware.org/ml/libc-alpha/2014-03/msg00491.html, second patch -
> http://sourceware.org/ml/libc-alpha/2014-03/msg00543.html) adding
> support for Intel MPX in Glibc for x86_64. Current change adds storing and
> restoring of bound registers in _dl_x86_64_save_sse and
> _dl_x86_64_restore_sse.
> >
> > Is it ok to install?
> >
> > 2014-03-19  Igor Zamyatin  <igor.zamyatin@intel.com>
> >
> >         * sysdeps/x86_64/tls.h (tcbhead_t): Add rtld_savespace_bnd field.
> >         * sysdeps/x86_64/tcb-offsets.sym: Add RTLD_SAVESPACE_BND.
> >         * sysdeps/x86_64/dl-trampoline.S (_dl_x86_64_save_sse): Add
> preserving
> >         of the Intel MPX bound registers.
> >         (_dl_x86_64_restore_sse): Add restoring of the Intel MPX bound
> >         registers.
> 
> Do we really need this since bound registers have been saved and restored
> in _dl_runtime_resolve?

Looks like you're right, saving/restoring in _dl_runtime_resolve should be enough


Thanks,
Igor

> 
> --
> H.J.