[RFC PATCH 02/10] C-SKY: TLS support

[Mao Han]

On Fri, Mar 16, 2018 at 08:09:10AM -0600, Carlos O'Donell wrote:
> On 03/16/2018 03:58 AM, Mao Han wrote:
> > This patch implements TLS support for C-SKY. We support all four
> > standard TLS addressing modes (LE, IE, LD, and GD) when running on
> > Linux via NPTL.
> > 
> >         *sysdeps/csky/dl-tls.h: New file
> >         *sysdeps/csky/libc-tls.c: New file
> >         *sysdeps/csky/nptl/tcb-offsets.sym: New file
> >         *sysdeps/csky/nptl/tls.h: New file
> >         *sysdeps/csky/stackinfo.h: New file
> > 
> 
> OK, fairly clean, was curious about stack guard and pointer guard support.
> 
> Others may have more to comment on this in libc-alpha.
> 
> > Signed-off-by: Mao Han <han_mao@c-sky.com>
> > ---
> >  sysdeps/csky/dl-tls.h             |  26 ++++++
> >  sysdeps/csky/libc-tls.c           |  32 ++++++++
> >  sysdeps/csky/nptl/tcb-offsets.sym |  10 +++
> >  sysdeps/csky/nptl/tls.h           | 169 ++++++++++++++++++++++++++++++++++++++
> >  sysdeps/csky/stackinfo.h          |  32 ++++++++
> >  5 files changed, 269 insertions(+)
> >  create mode 100644 sysdeps/csky/dl-tls.h
> >  create mode 100644 sysdeps/csky/libc-tls.c
> >  create mode 100644 sysdeps/csky/nptl/tcb-offsets.sym
> >  create mode 100644 sysdeps/csky/nptl/tls.h
> >  create mode 100644 sysdeps/csky/stackinfo.h
> > index 0000000..69fadad
> > --- /dev/null
> > +++ b/sysdeps/csky/nptl/tls.h
> > @@ -0,0 +1,169 @@
> > +/* Definitions for thread-local data handling.  NPTL/csky version.
> > +   Copyright (C) 2018 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library.  If not, see
> > +   <http://www.gnu.org/licenses/>.  */
> > +
> > +#ifndef _TLS_H
> > +#define _TLS_H 1
> > +
> > +#ifndef __ASSEMBLER__
> > +
> > +#include <stdbool.h>
> > +#include <stddef.h>
> > +#include <stdint.h>
> > +#include <dl-dtv.h>
> > +
> > +#ifdef __CSKYABIV2__
> > +/* define r31 as thread pointer register. */
> > +#define READ_THREAD_POINTER() \
> > +    ({ void *__result;						\
> > +       __asm__ __volatile__ ("mov %0, r31"			\
> > +                             : "=r" (__result));		\
> > +       __result; })
> > +#else
> > +#define READ_THREAD_POINTER() \
> > +    ({ register unsigned int __result __asm__("a0");		\
> > +       __asm__ __volatile__ ("trap 3;"				\
> > +                             : "=r" (__result) : : );		\
> > +       __result; })
> > +#endif
> > +
> > +#else /* __ASSEMBLER__ */
> > +#include <tcb-offsets.h>
> > +#ifdef __CSKYABIV2__
> > +/* define r31 as thread pointer register. */
> > +#define READ_THREAD_POINTER() \
> > +       mov r0, r31;	           
> > +#else
> > +#define READ_THREAD_POINTER() \
> > +       trap 3;             
> > +#endif
> > +#endif /* __ASSEMBLER__ */
> > +
> > +#ifndef __ASSEMBLER__
> > +
> > +/* Get system call information.  */
> > +#include <sysdep.h>
> > +
> > +/* The TP points to the start of the thread blocks.  */
> > +#define TLS_DTV_AT_TP	1
> > +#define TLS_TCB_AT_TP	0
> > +
> > +/* Get the thread descriptor definition.  */
> > +#include <nptl/descr.h>
> > +
> > +typedef struct
> > +{
> > +  dtv_t *dtv;
> > +  void *private;
> 
> Stack guard or pointer guard support?

We have global stack protect support using __stack_chk_guard, but SSP_TLS 
is not supported in our gcc. So there is no stack_guard here.
Pointer guard is not support at present. PTR_DEMANGLE and PTR_MANGLE are
defined empty. I think I'll add support for that later.

> 
> > +} tcbhead_t;
> > +