Re: [PATCH v4 3/4] linux: Consolidate sigaction implementation

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

If no one opposes it, I will commit this shortly.

On 19/02/2018 14:50, Adhemerval Zanella wrote:
> Ping.
> 
> On 12/02/2018 10:42, Adhemerval Zanella wrote:
>> This patch consolidates all Linux sigaction implementation on a default
>> one at sysdeps/unix/sysv/linux/sigaction.c.  The idea is remove redundant
>> code and simplify new ports addition by following the current generic
>> Linux User API (UAPI).
>>
>> The UAPI for new ports defines a generic extensible sigaction struct as:
>>
>>   struct sigaction
>>   {
>>     __sighandler_t sa_handler;
>>     unsigned long sa_flags;
>>   #ifdef SA_RESTORER
>>     void (*sa_restorer) (void);
>>   #endif
>>     sigset_t sa_mask;
>>   };
>>
>> Where SA_RESTORER is just placed to compatibility reasons, news ports
>> should not add it.  A similar definition is used on generic
>> kernel_sigaction.h.
>>
>> The user exported sigaction definition is not changed, so for most
>> architectures it requires an adjustment to kernel expected one for the
>> syscall.
>>
>> The main changes are:
>>
>>   - All architectures now define and use a kernel_sigaction struct meant
>>     for the syscall, even for the architectures where the user sigaction
>>     has the same layout of the kernel expected one (s390-64 and ia64).
>>     Although it requires more work for these architectures, it simplifies
>>     the generic implementation. Also, sigaction is hardly a hotspot where
>>     micro optimization would play an important role.
>>
>>   - The generic kernel_sigaction definition is now aligned with expected
>>     UAPI one for newer ports, where SA_RESTORER and sa_restorer is not
>>     expected to be defined.  This means adding kernel_sigaction for
>>     current architectures that does define it (m68k, nios2, powerpc, s390,
>>     sh, sparc, and tile) and which rely on previous generic definition.
>>
>>   - Remove old MIPS usage of sa_restorer.  This was removed since 2.6.27
>>     (2957c9e61ee9c - "[MIPS] IRIX: Goodbye and thanks for all the fish").
>>
>> So for new ports the generic implementation should work if its uses
>> Linux UAPI.  If SA_RESTORER is still required (due some architecture
>> limitation), it should define its own kernel_sigaction.h, define it and
>> include generic header (assuming it still uses the default generic kernel
>> layout).
>>
>> Checked on x86_64-linux-gnu, i686-linux-gnu, arm-linux-gnueabihf,
>> aarch64-linux-gnu, sparc64-linux-gnu, sparcv9-linux-gnu, powerpc-linux-gnu,
>> and powerpc64-linux-gnu.  I also check the build on all remaining affected
>> ABIs.
>>
>> 	* sysdeps/unix/sysv/linux/aarch64/sigaction.c: Use default Linux version
>> 	as base implementation.
>> 	* sysdeps/unix/sysv/linux/arm/sigaction.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/i386/sigaction.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/x86_64/sigaction.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h: Add include guards,
>> 	remove unrequired definitions and update comments.
>> 	* sysdeps/unix/sysv/linux/kernel_sigaction.h: Likewise.
>> 	* sysdeps/unix/sysv/linux/mips/kernel_sigaction.h: Likewise.
>> 	* sysdeps/unix/sysv/linux/ia64/kernel_sigaction.h: New file.
>> 	* sysdeps/unix/sysv/linux/m68k/kernel_sigaction.h: Likewise.
>> 	* sysdeps/unix/sysv/linux/nios2/kernel_sigaction.h: Likewise.
>> 	* sysdeps/unix/sysv/linux/powerpc/kernel_sigaction: Likewise.
>> 	* sysdeps/unix/sysv/linux/s390/kernel_sigaction.h: Likewise.
>> 	* sysdeps/unix/sysv/linux/sh/kernel_sigaction.h: Likewise.
>> 	* sysdeps/unix/sysv/linux/sparc/kernel_sigaction.h: Likewise.
>> 	* sysdeps/unix/sysv/linux/tile/kernel_sigaction.h: Likewise.
>> 	* sysdeps/unix/sysv/linux/ia64/sigaction.c: Remove file.
>> 	* sysdeps/unix/sysv/linux/mips/sigaction.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/s390/s390-64/sigaction.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/sigaction.c: Add STUB, SET_SA_RESTORER,
>> 	and RESET_SA_RESTORER hooks.
>>
>> Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
>> ---
>>  ChangeLog                                          |  25 +++++
>>  sysdeps/unix/sysv/linux/aarch64/sigaction.c        |  58 ++---------
>>  sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h   |  21 ++--
>>  sysdeps/unix/sysv/linux/arm/sigaction.c            |  79 +++-----------
>>  sysdeps/unix/sysv/linux/i386/sigaction.c           |  76 +++-----------
>>  sysdeps/unix/sysv/linux/ia64/kernel_sigaction.h    |   6 ++
>>  sysdeps/unix/sysv/linux/ia64/sigaction.c           |  45 --------
>>  sysdeps/unix/sysv/linux/kernel_sigaction.h         |  31 +++---
>>  sysdeps/unix/sysv/linux/m68k/kernel_sigaction.h    |  22 ++++
>>  sysdeps/unix/sysv/linux/mips/kernel_sigaction.h    |  48 ++-------
>>  sysdeps/unix/sysv/linux/mips/sigaction.c           | 116 ---------------------
>>  sysdeps/unix/sysv/linux/nios2/kernel_sigaction.h   |   8 ++
>>  sysdeps/unix/sysv/linux/powerpc/kernel_sigaction.h |   8 ++
>>  sysdeps/unix/sysv/linux/s390/kernel_sigaction.h    |  28 +++++
>>  sysdeps/unix/sysv/linux/s390/s390-64/sigaction.c   |  43 --------
>>  sysdeps/unix/sysv/linux/sh/kernel_sigaction.h      |   8 ++
>>  sysdeps/unix/sysv/linux/sigaction.c                |  28 ++---
>>  sysdeps/unix/sysv/linux/sparc/kernel_sigaction.h   |  10 ++
>>  sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c  |  41 +-------
>>  sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c  |  43 +-------
>>  sysdeps/unix/sysv/linux/tile/kernel_sigaction.h    |   9 ++
>>  sysdeps/unix/sysv/linux/x86_64/sigaction.c         |  61 ++---------
>>  22 files changed, 230 insertions(+), 584 deletions(-)
>>  create mode 100644 sysdeps/unix/sysv/linux/ia64/kernel_sigaction.h
>>  delete mode 100644 sysdeps/unix/sysv/linux/ia64/sigaction.c
>>  create mode 100644 sysdeps/unix/sysv/linux/m68k/kernel_sigaction.h
>>  delete mode 100644 sysdeps/unix/sysv/linux/mips/sigaction.c
>>  create mode 100644 sysdeps/unix/sysv/linux/nios2/kernel_sigaction.h
>>  create mode 100644 sysdeps/unix/sysv/linux/powerpc/kernel_sigaction.h
>>  create mode 100644 sysdeps/unix/sysv/linux/s390/kernel_sigaction.h
>>  delete mode 100644 sysdeps/unix/sysv/linux/s390/s390-64/sigaction.c
>>  create mode 100644 sysdeps/unix/sysv/linux/sh/kernel_sigaction.h
>>  create mode 100644 sysdeps/unix/sysv/linux/sparc/kernel_sigaction.h
>>  create mode 100644 sysdeps/unix/sysv/linux/tile/kernel_sigaction.h
>>
>> diff --git a/sysdeps/unix/sysv/linux/aarch64/sigaction.c b/sysdeps/unix/sysv/linux/aarch64/sigaction.c
>> index 73f4eb7..83d5b4f 100644
>> --- a/sysdeps/unix/sysv/linux/aarch64/sigaction.c
>> +++ b/sysdeps/unix/sysv/linux/aarch64/sigaction.c
>> @@ -1,5 +1,4 @@
>>  /* Copyright (C) 1997-2018 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
>> @@ -16,55 +15,16 @@
>>     License along with the GNU C Library; if not, see
>>     <http://www.gnu.org/licenses/>.  */
>>  
>> -#include <errno.h>
>> -#include <signal.h>
>> -#include <string.h>
>> -
>> -#include <sysdep.h>
>> -#include <sys/syscall.h>
>> -
>> +/* Required for AArch32 compatibility. */
>>  #define SA_RESTORER	0x04000000
>>  
>> -/* The difference here is that the sigaction structure used in the
>> -   kernel is not the same as we use in the libc.  Therefore we must
>> -   translate it here.  */
>> -#include <kernel_sigaction.h>
>> -
>> -int
>> -__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>> -{
>> -  int result;
>> -  struct kernel_sigaction kact;
>> -  struct kernel_sigaction koact;
>> -
>> -  if (act)
>> -    {
>> -      kact.k_sa_handler = act->sa_handler;
>> -      memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
>> -      kact.sa_flags = act->sa_flags;
>> -#ifdef HAVE_SA_RESTORER
>> -      if (kact.sa_flags & SA_RESTORER)
>> -	kact.sa_restorer = act->sa_restorer;
>> -#endif
>> -    }
>> +#define SET_SA_RESTORER(kact, act)				\
>> + ({								\
>> +    if ((kact)->sa_flags & SA_RESTORER)				\
>> +      (kact)->sa_restorer = (act)->sa_restorer;			\
>> + })
>>  
>> -  result = INLINE_SYSCALL (rt_sigaction, 4, sig,
>> -			   act ? &kact : NULL,
>> -			   oact ? &koact : NULL, _NSIG / 8);
>> -  if (result >= 0 || errno != ENOSYS)
>> -    {
>> -      if (oact && result >= 0)
>> -	{
>> -	  oact->sa_handler = koact.k_sa_handler;
>> -	  memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
>> -	  oact->sa_flags = koact.sa_flags;
>> -#ifdef HAVE_SA_RESTORER
>> -	  oact->sa_restorer = koact.sa_restorer;
>> -#endif
>> -	}
>> -    }
>> -  return result;
>> -}
>> -libc_hidden_def (__libc_sigaction)
>> +#define RESET_SA_RESTORER(act, kact)				\
>> +  (act)->sa_restorer = (kact)->sa_restorer;
>>  
>> -#include <nptl/sigaction.c>
>> +#include <sysdeps/unix/sysv/linux/sigaction.c>
>> diff --git a/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h b/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
>> index 4c35d96..25180ff 100644
>> --- a/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
>> +++ b/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
>> @@ -1,15 +1,12 @@
>> -/* This is the sigaction struction from the Linux 2.1.20 kernel.  */
>> +#ifndef _KERNEL_SIGACTION_H
>> +# define _KERNEL_SIGACTION_H
>>  
>> -struct old_kernel_sigaction {
>> -	__sighandler_t k_sa_handler;
>> -	unsigned long sa_mask;
>> -	unsigned int sa_flags;
>> +/* This is the sigaction structure from the Linux 3.2 kernel.  */
>> +struct kernel_sigaction
>> +{
>> +  __sighandler_t k_sa_handler;
>> +  unsigned int sa_flags;
>> +  sigset_t sa_mask;
>>  };
>>  
>> -/* This is the sigaction structure from the Linux 2.1.68 kernel.  */
>> -
>> -struct kernel_sigaction {
>> -	__sighandler_t k_sa_handler;
>> -	unsigned int sa_flags;
>> -	sigset_t sa_mask;
>> -};
>> +#endif
>> diff --git a/sysdeps/unix/sysv/linux/arm/sigaction.c b/sysdeps/unix/sysv/linux/arm/sigaction.c
>> index e4d80de..c828250 100644
>> --- a/sysdeps/unix/sysv/linux/arm/sigaction.c
>> +++ b/sysdeps/unix/sysv/linux/arm/sigaction.c
>> @@ -15,70 +15,25 @@
>>     License along with the GNU C Library.  If not, see
>>     <http://www.gnu.org/licenses/>.  */
>>  
>> -#include <errno.h>
>> -#include <signal.h>
>> -#include <string.h>
>> -
>> -#include <sysdep.h>
>> -#include <sys/syscall.h>
>> -
>> -/* The difference here is that the sigaction structure used in the
>> -   kernel is not the same as we use in the libc.  Therefore we must
>> -   translate it here.  */
>> -#include <kernel_sigaction.h>
>> -
>>  #define SA_RESTORER	0x04000000
>>  
>>  extern void __default_sa_restorer (void);
>>  extern void __default_rt_sa_restorer (void);
>>  
>> -/* When RT signals are in use we need to use a different return stub.  */
>> -#define choose_restorer(flags)					\
>> -  (flags & SA_SIGINFO) ? __default_rt_sa_restorer		\
>> -  : __default_sa_restorer
>> -
>> -/* If ACT is not NULL, change the action for SIG to *ACT.
>> -   If OACT is not NULL, put the old action for SIG in *OACT.  */
>> -int
>> -__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>> -{
>> -  int result;
>> -
>> -  struct kernel_sigaction kact, koact;
>> -
>> -  if (act)
>> -    {
>> -      kact.k_sa_handler = act->sa_handler;
>> -      memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
>> -      kact.sa_flags = act->sa_flags;
>> -#ifdef HAVE_SA_RESTORER
>> -      if (kact.sa_flags & SA_RESTORER)
>> -	kact.sa_restorer = act->sa_restorer;
>> -      else
>> -	{
>> -	  kact.sa_restorer = choose_restorer (kact.sa_flags);
>> -	  kact.sa_flags |= SA_RESTORER;
>> -	}
>> -#endif
>> -    }
>> -
>> -  /* XXX The size argument hopefully will have to be changed to the
>> -     real size of the user-level sigset_t.  */
>> -  result = INLINE_SYSCALL (rt_sigaction, 4, sig,
>> -			   act ? &kact : NULL,
>> -			   oact ? &koact : NULL, _NSIG / 8);
>> -
>> -  if (oact && result >= 0)
>> -    {
>> -      oact->sa_handler = koact.k_sa_handler;
>> -      memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
>> -      oact->sa_flags = koact.sa_flags;
>> -#ifdef HAVE_SA_RESTORER
>> -      oact->sa_restorer = koact.sa_restorer;
>> -#endif
>> -    }
>> -  return result;
>> -}
>> -libc_hidden_def (__libc_sigaction)
>> -
>> -#include <nptl/sigaction.c>
>> +#define SET_SA_RESTORER(kact, act)				\
>> + ({								\
>> +   if ((kact)->sa_flags & SA_RESTORER)				\
>> +     (kact)->sa_restorer = (act)->sa_restorer;			\
>> +   else								\
>> +     {								\
>> +       (kact)->sa_restorer = ((kact)->sa_flags & SA_SIGINFO)	\
>> +			     ? __default_rt_sa_restorer		\
>> +			     : __default_sa_restorer;		\
>> +       (kact)->sa_flags |= SA_RESTORER;				\
>> +     }								\
>> + })
>> +
>> +#define RESET_SA_RESTORER(act, kact)				\
>> +  (act)->sa_restorer = (kact)->sa_restorer;
>> +
>> +#include <sysdeps/unix/sysv/linux/sigaction.c>
>> diff --git a/sysdeps/unix/sysv/linux/i386/sigaction.c b/sysdeps/unix/sysv/linux/i386/sigaction.c
>> index a5eb9e0..137c73b 100644
>> --- a/sysdeps/unix/sysv/linux/i386/sigaction.c
>> +++ b/sysdeps/unix/sysv/linux/i386/sigaction.c
>> @@ -16,78 +16,28 @@
>>     License along with the GNU C Library; if not, see
>>     <http://www.gnu.org/licenses/>.  */
>>  
>> -#include <sysdep.h>
>> -#include <errno.h>
>> -#include <stddef.h>
>>  #include <signal.h>
>> -#include <string.h>
>> -
>> -#include <sysdep.h>
>> -#include <sys/syscall.h>
>>  #include <ldsodefs.h>
>>  
>> -/* The difference here is that the sigaction structure used in the
>> -   kernel is not the same as we use in the libc.  Therefore we must
>> -   translate it here.  */
>> -#include <kernel_sigaction.h>
>> -
>> -/* We do not globally define the SA_RESTORER flag so do it here.  */
>>  #define SA_RESTORER 0x04000000
>>  
>> -
>> -/* Using the hidden attribute here does not change the code but it
>> -   helps to avoid warnings.  */
>> -#ifdef __NR_rt_sigaction
>>  extern void restore_rt (void) asm ("__restore_rt") attribute_hidden;
>> -#endif
>>  extern void restore (void) asm ("__restore") attribute_hidden;
>>  
>> +#define SET_SA_RESTORER(kact, act)				\
>> +  ({								\
>> +     if (GLRO(dl_sysinfo_dso) == NULL)				\
>> +       {							\
>> +	 (kact)->sa_flags |= SA_RESTORER;			\
>> +         (kact)->sa_restorer = (((act)->sa_flags & SA_SIGINFO)	\
>> +			       ? &restore_rt : &restore);	\
>> +       }							\
>> +  })
>>  
>> -/* If ACT is not NULL, change the action for SIG to *ACT.
>> -   If OACT is not NULL, put the old action for SIG in *OACT.  */
>> -int
>> -__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>> -{
>> -  int result;
>> -
>> -  struct kernel_sigaction kact, koact;
>> -
>> -  if (act)
>> -    {
>> -      kact.k_sa_handler = act->sa_handler;
>> -      kact.sa_flags = act->sa_flags;
>> -      memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
>> -
>> -      if (GLRO(dl_sysinfo_dso) == NULL)
>> -	{
>> -	  kact.sa_flags |= SA_RESTORER;
>> -
>> -	  kact.sa_restorer = ((act->sa_flags & SA_SIGINFO)
>> -			      ? &restore_rt : &restore);
>> -	}
>> -    }
>> -
>> -  /* XXX The size argument hopefully will have to be changed to the
>> -     real size of the user-level sigset_t.  */
>> -  INTERNAL_SYSCALL_DECL (err);
>> -  result = INTERNAL_SYSCALL (rt_sigaction, err, 4,
>> -			     sig, act ? &kact : NULL,
>> -			     oact ? &koact : NULL, _NSIG / 8);
>> -  if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, err)))
>> -     return INLINE_SYSCALL_ERROR_RETURN_VALUE (INTERNAL_SYSCALL_ERRNO (result,
>> -								       err));
>> -  else if (oact && result >= 0)
>> -    {
>> -      oact->sa_handler = koact.k_sa_handler;
>> -      memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
>> -      oact->sa_flags = koact.sa_flags;
>> -      oact->sa_restorer = koact.sa_restorer;
>> -    }
>> -  return result;
>> -}
>> -libc_hidden_def (__libc_sigaction)
>> +#define RESET_SA_RESTORER(act, kact) \
>> +  (act)->sa_restorer = (kact)->sa_restorer
>>  
>> -#include <nptl/sigaction.c>
>> +#include <sysdeps/unix/sysv/linux/sigaction.c>
>>  
>>  /* NOTE: Please think twice before making any changes to the bits of
>>     code below.  GDB needs some intimate knowledge about it to
>> @@ -108,10 +58,8 @@ asm						\
>>     "	int  $0x80"				\
>>     );
>>  
>> -#ifdef __NR_rt_sigaction
>>  /* The return code for realtime-signals.  */
>>  RESTORE (restore_rt, __NR_rt_sigreturn)
>> -#endif
>>  
>>  /* For the boring old signals.  */
>>  #undef RESTORE2
>> diff --git a/sysdeps/unix/sysv/linux/ia64/kernel_sigaction.h b/sysdeps/unix/sysv/linux/ia64/kernel_sigaction.h
>> new file mode 100644
>> index 0000000..05813db
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/ia64/kernel_sigaction.h
>> @@ -0,0 +1,6 @@
>> +/* This is the sigaction structure from the Linux 3.2 kernel.  */
>> +struct kernel_sigaction {
>> +        __sighandler_t k_sa_handler;
>> +        unsigned long sa_flags;
>> +        sigset_t sa_mask;               /* mask last for extensibility */
>> +};
>> diff --git a/sysdeps/unix/sysv/linux/ia64/sigaction.c b/sysdeps/unix/sysv/linux/ia64/sigaction.c
>> deleted file mode 100644
>> index e7fb8cd..0000000
>> --- a/sysdeps/unix/sysv/linux/ia64/sigaction.c
>> +++ /dev/null
>> @@ -1,45 +0,0 @@
>> -/* Copyright (C) 1997-2018 Free Software Foundation, Inc.
>> -   This file is part of the GNU C Library.
>> -   Linux/IA64 specific sigaction
>> -   Written by Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.
>> -
>> -   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/>.  */
>> -
>> -/* Linux/ia64 only has rt signals, thus we do not even want to try falling
>> -   back to the old style signals as the default Linux handler does. */
>> -
>> -#include <errno.h>
>> -#include <signal.h>
>> -#include <string.h>
>> -
>> -#include <sysdep.h>
>> -#include <sys/syscall.h>
>> -
>> -/* The variable is shared between all wrappers around signal handling
>> -   functions which have RT equivalents.  This is the definition.  */
>> -
>> -
>> -/* If ACT is not NULL, change the action for SIG to *ACT.
>> -   If OACT is not NULL, put the old action for SIG in *OACT.  */
>> -int
>> -__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>> -{
>> -  /* XXX The size argument hopefully will have to be changed to the
>> -     real size of the user-level sigset_t.  */
>> -  return INLINE_SYSCALL (rt_sigaction, 4, sig, act, oact, _NSIG / 8);
>> -}
>> -libc_hidden_def (__libc_sigaction)
>> -
>> -#include <nptl/sigaction.c>
>> diff --git a/sysdeps/unix/sysv/linux/kernel_sigaction.h b/sysdeps/unix/sysv/linux/kernel_sigaction.h
>> index d005cbc..2dbec08 100644
>> --- a/sysdeps/unix/sysv/linux/kernel_sigaction.h
>> +++ b/sysdeps/unix/sysv/linux/kernel_sigaction.h
>> @@ -1,19 +1,20 @@
>> -/* This is the sigaction structure from the Linux 2.1.20 kernel.  */
>> +#ifndef _KERNEL_SIGACTION_H
>> +# define _KERNEL_SIGACTION_H
>>  
>> -#define HAVE_SA_RESTORER
>> -
>> -struct old_kernel_sigaction {
>> -	__sighandler_t k_sa_handler;
>> -	unsigned long sa_mask;
>> -	unsigned long sa_flags;
>> -	void (*sa_restorer) (void);
>> +/* This is the sigaction structure from the Linux 3.2 kernel.  */
>> +struct kernel_sigaction
>> +{
>> +  __sighandler_t k_sa_handler;
>> +  unsigned long sa_flags;
>> +#ifdef SA_RESTORER
>> +  void (*sa_restorer) (void);
>> +#endif
>> +  sigset_t sa_mask;
>>  };
>>  
>> -/* This is the sigaction structure from the Linux 2.1.68 kernel.  */
>> +#ifndef SA_RESTORER
>> +# define SET_SA_RESTORER(kact, act)
>> +# define RESET_SA_RESTORER(act, kact)
>> +#endif
>>  
>> -struct kernel_sigaction {
>> -	__sighandler_t k_sa_handler;
>> -	unsigned long sa_flags;
>> -	void (*sa_restorer) (void);
>> -	sigset_t sa_mask;
>> -};
>> +#endif
>> diff --git a/sysdeps/unix/sysv/linux/m68k/kernel_sigaction.h b/sysdeps/unix/sysv/linux/m68k/kernel_sigaction.h
>> new file mode 100644
>> index 0000000..54972fe
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/m68k/kernel_sigaction.h
>> @@ -0,0 +1,22 @@
>> +#ifndef _KERNEL_SIGACTION_H
>> +# define _KERNEL_SIGACTION_H
>> +
>> +#include <signal.h>
>> +
>> +#define SA_RESTORER 0x04000000
>> +
>> +/* This is the sigaction structure from the Linux 3.2 kernel.  */
>> +struct kernel_sigaction
>> +{
>> +  __sighandler_t k_sa_handler;
>> +  sigset_t sa_mask;
>> +  unsigned long sa_flags;
>> +  void (*sa_restorer) (void);
>> +};
>> +
>> +#define SET_SA_RESTORER(kact, act)			\
>> +  (kact)->sa_restorer = (act)->sa_restorer
>> +#define RESET_SA_RESTORER(act, kact)			\
>> +  (act)->sa_restorer = (kact)->sa_restorer
>> +
>> +#endif
>> diff --git a/sysdeps/unix/sysv/linux/mips/kernel_sigaction.h b/sysdeps/unix/sysv/linux/mips/kernel_sigaction.h
>> index b6f52cc..beef976 100644
>> --- a/sysdeps/unix/sysv/linux/mips/kernel_sigaction.h
>> +++ b/sysdeps/unix/sysv/linux/mips/kernel_sigaction.h
>> @@ -1,40 +1,12 @@
>> -/* This is the sigaction structure from the Linux 2.1.24 kernel.  */
>> -
>> -#include <sgidefs.h>
>> -
>> -#define HAVE_SA_RESTORER
>> -
>> -struct old_kernel_sigaction {
>> -	unsigned int	sa_flags;
>> -	__sighandler_t	k_sa_handler;
>> -	unsigned long	sa_mask;
>> -	unsigned int    __pad0[3]; /* reserved, keep size constant */
>> -
>> -	/* Abi says here follows reserved int[2] */
>> -	void		(*sa_restorer)(void);
>> -#if (_MIPS_SZPTR < 64)
>> -	/*
>> -	 * For 32 bit code we have to pad struct sigaction to get
>> -	 * constant size for the ABI
>> -	 */
>> -	int		pad1[1]; /* reserved */
>> -#endif
>> +#ifndef _KERNEL_SIGACTION_H
>> +# define _KERNEL_SIGACTION_H
>> +
>> +/* This is the sigaction structure from the Linux 3.2 kernel.  */
>> +struct kernel_sigaction
>> +{
>> +  unsigned int    sa_flags;
>> +  __sighandler_t  k_sa_handler;
>> +  sigset_t        sa_mask;
>>  };
>>  
>> -
>> -#define _KERNEL_NSIG	       128
>> -#define _KERNEL_NSIG_BPW       _MIPS_SZLONG
>> -#define _KERNEL_NSIG_WORDS     (_KERNEL_NSIG / _KERNEL_NSIG_BPW)
>> -
>> -typedef struct {
>> -	unsigned long sig[_KERNEL_NSIG_WORDS];
>> -} kernel_sigset_t;
>> -
>> -/* This is the sigaction structure from the Linux 2.1.68 kernel.  */
>> -struct kernel_sigaction {
>> -	unsigned int	sa_flags;
>> -	__sighandler_t	k_sa_handler;
>> -	kernel_sigset_t	sa_mask;
>> -	void		(*sa_restorer)(void);
>> -	int		s_resv[1]; /* reserved */
>> -};
>> +#endif
>> diff --git a/sysdeps/unix/sysv/linux/mips/sigaction.c b/sysdeps/unix/sysv/linux/mips/sigaction.c
>> deleted file mode 100644
>> index 008b688..0000000
>> --- a/sysdeps/unix/sysv/linux/mips/sigaction.c
>> +++ /dev/null
>> @@ -1,116 +0,0 @@
>> -/* Copyright (C) 1997-2018 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/>.  */
>> -
>> -#include <errno.h>
>> -#include <sgidefs.h>
>> -#include <signal.h>
>> -#include <string.h>
>> -
>> -#include <sysdep.h>
>> -#include <sys/syscall.h>
>> -
>> -#include <sgidefs.h>
>> -
>> -/* The difference here is that the sigaction structure used in the
>> -   kernel is not the same as we use in the libc.  Therefore we must
>> -   translate it here.  */
>> -#include <kernel_sigaction.h>
>> -
>> -#if _MIPS_SIM != _ABIO32
>> -
>> -# ifdef __NR_rt_sigreturn
>> -static void restore_rt (void) asm ("__restore_rt");
>> -# endif
>> -# ifdef __NR_sigreturn
>> -static void restore (void) asm ("__restore");
>> -# endif
>> -#endif
>> -
>> -/* If ACT is not NULL, change the action for SIG to *ACT.
>> -   If OACT is not NULL, put the old action for SIG in *OACT.  */
>> -int
>> -__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>> -{
>> -  int result;
>> -
>> -  struct kernel_sigaction kact, koact;
>> -
>> -  if (act)
>> -    {
>> -      kact.k_sa_handler = act->sa_handler;
>> -      memcpy (&kact.sa_mask, &act->sa_mask, sizeof (kernel_sigset_t));
>> -      kact.sa_flags = act->sa_flags;
>> -#ifdef HAVE_SA_RESTORER
>> -# if _MIPS_SIM == _ABIO32
>> -      kact.sa_restorer = act->sa_restorer;
>> -# else
>> -      kact.sa_restorer = &restore_rt;
>> -# endif
>> -#endif
>> -    }
>> -
>> -  /* XXX The size argument hopefully will have to be changed to the
>> -     real size of the user-level sigset_t.	*/
>> -  result = INLINE_SYSCALL (rt_sigaction, 4, sig,
>> -			   act ? &kact : NULL,
>> -			   oact ? &koact : NULL,
>> -			   sizeof (kernel_sigset_t));
>> -
>> -  if (oact && result >= 0)
>> -    {
>> -      oact->sa_handler = koact.k_sa_handler;
>> -      memcpy (&oact->sa_mask, &koact.sa_mask,
>> -	      sizeof (kernel_sigset_t));
>> -      oact->sa_flags = koact.sa_flags;
>> -#ifdef HAVE_SA_RESTORER
>> -      oact->sa_restorer = koact.sa_restorer;
>> -#endif
>> -    }
>> -  return result;
>> -}
>> -libc_hidden_def (__libc_sigaction)
>> -
>> -#include <nptl/sigaction.c>
>> -
>> -
>> -/* NOTE: Please think twice before making any changes to the bits of
>> -   code below.  GDB needs some intimate knowledge about it to
>> -   recognize them as signal trampolines, and make backtraces through
>> -   signal handlers work right.  Important are both the names
>> -   (__restore_rt) and the exact instruction sequence.
>> -   If you ever feel the need to make any changes, please notify the
>> -   appropriate GDB maintainer.  */
>> -
>> -#define RESTORE(name, syscall) RESTORE2 (name, syscall)
>> -#define RESTORE2(name, syscall) \
>> -asm						\
>> -  (						\
>> -   ".align 4\n"					\
>> -   "__" #name ":\n"				\
>> -   "	li $2, " #syscall "\n"			\
>> -   "	syscall\n"				\
>> -   );
>> -
>> -/* The return code for realtime-signals.  */
>> -#if _MIPS_SIM != _ABIO32
>> -# ifdef __NR_rt_sigreturn
>> -RESTORE (restore_rt, __NR_rt_sigreturn)
>> -# endif
>> -# ifdef __NR_sigreturn
>> -RESTORE (restore, __NR_sigreturn)
>> -# endif
>> -#endif
>> diff --git a/sysdeps/unix/sysv/linux/nios2/kernel_sigaction.h b/sysdeps/unix/sysv/linux/nios2/kernel_sigaction.h
>> new file mode 100644
>> index 0000000..4ada322
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/nios2/kernel_sigaction.h
>> @@ -0,0 +1,8 @@
>> +/* NIOS2 uses the generic Linux UAPI but defines SA_RESTORER.  */
>> +#define SA_RESTORER 0x04000000
>> +#include <sysdeps/unix/sysv/linux/kernel_sigaction.h>
>> +
>> +#define SET_SA_RESTORER(kact, act)             \
>> +  (kact)->sa_restorer = (act)->sa_restorer
>> +#define RESET_SA_RESTORER(act, kact)           \
>> +  (act)->sa_restorer = (kact)->sa_restorer
>> diff --git a/sysdeps/unix/sysv/linux/powerpc/kernel_sigaction.h b/sysdeps/unix/sysv/linux/powerpc/kernel_sigaction.h
>> new file mode 100644
>> index 0000000..c5213f2
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/powerpc/kernel_sigaction.h
>> @@ -0,0 +1,8 @@
>> +/* powerpc kernel sigaction is similar to generic Linux UAPI one.  */
>> +#define SA_RESTORER 0x04000000
>> +#include <sysdeps/unix/sysv/linux/kernel_sigaction.h>
>> +
>> +#define SET_SA_RESTORER(kact, act)             \
>> +  (kact)->sa_restorer = (act)->sa_restorer
>> +#define RESET_SA_RESTORER(act, kact)           \
>> +  (act)->sa_restorer = (kact)->sa_restorer
>> diff --git a/sysdeps/unix/sysv/linux/s390/kernel_sigaction.h b/sysdeps/unix/sysv/linux/s390/kernel_sigaction.h
>> new file mode 100644
>> index 0000000..a8beaf7
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/s390/kernel_sigaction.h
>> @@ -0,0 +1,28 @@
>> +#include <bits/types/siginfo_t.h>
>> +
>> +#define SA_RESTORER	0x04000000
>> +
>> +/* This is the sigaction structure from the Linux 3.2 kernel.  */
>> +struct kernel_sigaction
>> +{
>> +  union
>> +  {
>> +    __sighandler_t _sa_handler;
>> +    void (*_sa_sigaction)(int, siginfo_t *, void *);
>> +  } _u;
>> +#define k_sa_handler _u._sa_handler
>> +#ifndef __s390x__
>> +  sigset_t sa_mask;
>> +  unsigned long sa_flags;
>> +  void (*sa_restorer)(void);
>> +#else
>> +  unsigned long sa_flags;
>> +  void (*sa_restorer)(void);
>> +  sigset_t sa_mask;
>> +#endif
>> +};
>> +
>> +#define SET_SA_RESTORER(kact, act)             \
>> +  (kact)->sa_restorer = (act)->sa_restorer
>> +#define RESET_SA_RESTORER(act, kact)           \
>> +  (act)->sa_restorer = (kact)->sa_restorer
>> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/sigaction.c b/sysdeps/unix/sysv/linux/s390/s390-64/sigaction.c
>> deleted file mode 100644
>> index c13927c..0000000
>> --- a/sysdeps/unix/sysv/linux/s390/s390-64/sigaction.c
>> +++ /dev/null
>> @@ -1,43 +0,0 @@
>> -/* Copyright (C) 2001-2018 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/>.  */
>> -
>> -/* 64 bit Linux for S/390 only has rt signals, thus we do not even want to try
>> -   falling back to the old style signals as the default Linux handler does. */
>> -
>> -#include <errno.h>
>> -#include <signal.h>
>> -#include <string.h>
>> -
>> -#include <sysdep.h>
>> -#include <sys/syscall.h>
>> -
>> -/* The variable is shared between all wrappers around signal handling
>> -   functions which have RT equivalents.  This is the definition.  */
>> -
>> -
>> -/* If ACT is not NULL, change the action for SIG to *ACT.
>> -   If OACT is not NULL, put the old action for SIG in *OACT.  */
>> -int
>> -__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>> -{
>> -  /* XXX The size argument hopefully will have to be changed to the
>> -     real size of the user-level sigset_t.  */
>> -  return INLINE_SYSCALL (rt_sigaction, 4, sig, act, oact, _NSIG / 8);
>> -}
>> -libc_hidden_def (__libc_sigaction)
>> -
>> -#include <nptl/sigaction.c>
>> diff --git a/sysdeps/unix/sysv/linux/sh/kernel_sigaction.h b/sysdeps/unix/sysv/linux/sh/kernel_sigaction.h
>> new file mode 100644
>> index 0000000..7ebcd08
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/sh/kernel_sigaction.h
>> @@ -0,0 +1,8 @@
>> +/* SH uses the generic Linux UAPI but defines SA_RESTORER.  */
>> +#define SA_RESTORER 0x04000000
>> +#include <sysdeps/unix/sysv/linux/kernel_sigaction.h>
>> +
>> +#define SET_SA_RESTORER(kact, act)             \
>> +  (kact)->sa_restorer = (act)->sa_restorer
>> +#define RESET_SA_RESTORER(act, kact)           \
>> +  (act)->sa_restorer = (kact)->sa_restorer
>> diff --git a/sysdeps/unix/sysv/linux/sigaction.c b/sysdeps/unix/sysv/linux/sigaction.c
>> index 40a311a..0e6851a 100644
>> --- a/sysdeps/unix/sysv/linux/sigaction.c
>> +++ b/sysdeps/unix/sysv/linux/sigaction.c
>> @@ -22,11 +22,19 @@
>>  #include <sysdep.h>
>>  #include <sys/syscall.h>
>>  
>> -/* The difference here is that the sigaction structure used in the
>> -   kernel is not the same as we use in the libc.  Therefore we must
>> -   translate it here.  */
>> +/* New ports should not define the obsolete SA_RESTORER, however some
>> +   architecture requires for compat mode and/or due old ABI.  */
>>  #include <kernel_sigaction.h>
>>  
>> +#ifndef SA_RESTORER
>> +# define SET_SA_RESTORER(kact, act)
>> +# define RESET_SA_RESTORER(act, kact)
>> +#endif
>> +
>> +/* SPARC passes the restore function as an argument to rt_sigaction.  */
>> +#ifndef STUB
>> +# define STUB(act)
>> +#endif
>>  
>>  /* If ACT is not NULL, change the action for SIG to *ACT.
>>     If OACT is not NULL, put the old action for SIG in *OACT.  */
>> @@ -42,25 +50,21 @@ __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>>        kact.k_sa_handler = act->sa_handler;
>>        memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
>>        kact.sa_flags = act->sa_flags;
>> -#ifdef HAVE_SA_RESTORER
>> -      kact.sa_restorer = act->sa_restorer;
>> -#endif
>> +      SET_SA_RESTORER (&kact, act);
>>      }
>>  
>>    /* XXX The size argument hopefully will have to be changed to the
>>       real size of the user-level sigset_t.  */
>> -  result = INLINE_SYSCALL (rt_sigaction, 4, sig,
>> -			   act ? &kact : NULL,
>> -			   oact ? &koact : NULL, _NSIG / 8);
>> +  result = INLINE_SYSCALL_CALL (rt_sigaction, sig,
>> +				act ? &kact : NULL,
>> +				oact ? &koact : NULL, STUB(act) _NSIG / 8);
>>  
>>    if (oact && result >= 0)
>>      {
>>        oact->sa_handler = koact.k_sa_handler;
>>        memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
>>        oact->sa_flags = koact.sa_flags;
>> -#ifdef HAVE_SA_RESTORER
>> -      oact->sa_restorer = koact.sa_restorer;
>> -#endif
>> +      RESET_SA_RESTORER (oact, &koact);
>>      }
>>    return result;
>>  }
>> diff --git a/sysdeps/unix/sysv/linux/sparc/kernel_sigaction.h b/sysdeps/unix/sysv/linux/sparc/kernel_sigaction.h
>> new file mode 100644
>> index 0000000..bee7e9c
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/sparc/kernel_sigaction.h
>> @@ -0,0 +1,10 @@
>> +/* SPARC 'struct __new_sigaction' is similar to generic Linux UAPI with
>> +   a sa_restorer field, even though function is passed as an argument
>> +   to rt_sigaction syscall.  */
>> +#define SA_RESTORER 0x04000000
>> +#include <sysdeps/unix/sysv/linux/kernel_sigaction.h>
>> +
>> +#define SET_SA_RESTORER(kact, act)             \
>> +  (kact)->sa_restorer = NULL
>> +#define RESET_SA_RESTORER(act, kact)           \
>> +  (act)->sa_restorer = (kact)->sa_restorer
>> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c b/sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c
>> index 204a5d8..c1d8f45 100644
>> --- a/sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c
>> +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c
>> @@ -27,43 +27,12 @@
>>  static void __rt_sigreturn_stub (void);
>>  static void __sigreturn_stub (void);
>>  
>> -int
>> -__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>> -{
>> -  struct kernel_sigaction kact, koact;
>> -  unsigned long stub = 0;
>> -  int ret;
>> -
>> -  if (act)
>> -    {
>> -      kact.k_sa_handler = act->sa_handler;
>> -      memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
>> -      if (((kact.sa_flags = act->sa_flags) & SA_SIGINFO) != 0)
>> -	stub = (unsigned long) &__rt_sigreturn_stub;
>> -      else
>> -	stub = (unsigned long) &__sigreturn_stub;
>> -      stub -= 8;
>> -      kact.sa_restorer = NULL;
>> -    }
>> -
>> -  /* XXX The size argument hopefully will have to be changed to the
>> -     real size of the user-level sigset_t.  */
>> -  ret = INLINE_SYSCALL (rt_sigaction, 5, sig, act ? &kact : 0,
>> -			oact ? &koact : 0, stub, _NSIG / 8);
>> -
>> -  if (oact && ret >= 0)
>> -    {
>> -      oact->sa_handler = koact.k_sa_handler;
>> -      memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
>> -      oact->sa_flags = koact.sa_flags;
>> -      oact->sa_restorer = koact.sa_restorer;
>> -    }
>> -  return ret;
>> -}
>> -libc_hidden_def (__libc_sigaction)
>> -
>> -#include <nptl/sigaction.c>
>> +#define STUB(act) \
>> +  ((unsigned long)((act->sa_flags & SA_SIGINFO)		\
>> +		    ? &__rt_sigreturn_stub		\
>> +		    : &__sigreturn_stub) - 8),
>>  
>> +#include <sysdeps/unix/sysv/linux/sigaction.c>
>>  
>>  static
>>  inhibit_stack_protector
>> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c b/sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c
>> index 73cda4c..cfbbc6e 100644
>> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c
>> +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c
>> @@ -21,50 +21,13 @@
>>  #include <string.h>
>>  #include <syscall.h>
>>  #include <sysdep.h>
>> -#include <sys/signal.h>
>> -#include <errno.h>
>> -
>> -#include <kernel_sigaction.h>
>> -
>> -/* SPARC 64bit userland requires a kernel that has rt signals anyway. */
>>  
>>  static void __rt_sigreturn_stub (void);
>>  
>> -int
>> -__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>> -{
>> -  int ret;
>> -  struct kernel_sigaction kact, koact;
>> -  unsigned long stub = ((unsigned long) &__rt_sigreturn_stub) - 8;
>> -
>> -  if (act)
>> -    {
>> -      kact.k_sa_handler = act->sa_handler;
>> -      memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
>> -      kact.sa_flags = act->sa_flags;
>> -      kact.sa_restorer = NULL;
>> -    }
>> -
>> -  /* XXX The size argument hopefully will have to be changed to the
>> -     real size of the user-level sigset_t.  */
>> -  ret = INLINE_SYSCALL (rt_sigaction, 5, sig,
>> -			act ? &kact : 0,
>> -			oact ? &koact : 0, stub, _NSIG / 8);
>> -
>> -  if (oact && ret >= 0)
>> -    {
>> -      oact->sa_handler = koact.k_sa_handler;
>> -      memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
>> -      oact->sa_flags = koact.sa_flags;
>> -      oact->sa_restorer = koact.sa_restorer;
>> -    }
>> -
>> -  return ret;
>> -}
>> -libc_hidden_def (__libc_sigaction)
>> -
>> -#include <nptl/sigaction.c>
>> +#define STUB(act) \
>> +  (((unsigned long) &__rt_sigreturn_stub) - 8),
>>  
>> +#include <sysdeps/unix/sysv/linux/sigaction.c>
>>  
>>  static
>>  inhibit_stack_protector
>> diff --git a/sysdeps/unix/sysv/linux/tile/kernel_sigaction.h b/sysdeps/unix/sysv/linux/tile/kernel_sigaction.h
>> new file mode 100644
>> index 0000000..a943d52
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/tile/kernel_sigaction.h
>> @@ -0,0 +1,9 @@
>> +/* tile kernel sigaction is similar to generic Linux UAPI one
>> +   and SA_RESTORER is used only for binary compatibility.  */
>> +#define SA_RESTORER 0x04000000
>> +#include <sysdeps/unix/sysv/linux/kernel_sigaction.h>
>> +
>> +#define SET_SA_RESTORER(kact, act)             \
>> +  (kact)->sa_restorer = (act)->sa_restorer
>> +#define RESET_SA_RESTORER(act, kact)           \
>> +  (act)->sa_restorer = (kact)->sa_restorer
>> diff --git a/sysdeps/unix/sysv/linux/x86_64/sigaction.c b/sysdeps/unix/sysv/linux/x86_64/sigaction.c
>> index 2f7459f..4e6d9cc 100644
>> --- a/sysdeps/unix/sysv/linux/x86_64/sigaction.c
>> +++ b/sysdeps/unix/sysv/linux/x86_64/sigaction.c
>> @@ -16,65 +16,20 @@
>>     License along with the GNU C Library; if not, see
>>     <http://www.gnu.org/licenses/>.  */
>>  
>> -#include <sysdep.h>
>> -#include <errno.h>
>> -#include <stddef.h>
>>  #include <signal.h>
>> -#include <string.h>
>> -
>> -#include <sysdep.h>
>> -#include <sys/syscall.h>
>> -
>> -/* The difference here is that the sigaction structure used in the
>> -   kernel is not the same as we use in the libc.  Therefore we must
>> -   translate it here.  */
>> -#include <kernel_sigaction.h>
>> -
>> -#include "ucontext_i.h"
>> -
>> -/* We do not globally define the SA_RESTORER flag so do it here.  */
>>  #define SA_RESTORER 0x04000000
>> +#include <kernel_sigaction.h>
>>  
>> -/* Using the hidden attribute here does not change the code but it
>> -   helps to avoid warnings.  */
>>  extern void restore_rt (void) asm ("__restore_rt") attribute_hidden;
>>  
>> +#define SET_SA_RESTORER(kact, act)			\
>> +  (kact)->sa_flags = (act)->sa_flags | SA_RESTORER;	\
>> +  (kact)->sa_restorer = &restore_rt
>>  
>> -/* If ACT is not NULL, change the action for SIG to *ACT.
>> -   If OACT is not NULL, put the old action for SIG in *OACT.  */
>> -int
>> -__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>> -{
>> -  int result;
>> -  struct kernel_sigaction kact, koact;
>> -
>> -  if (act)
>> -    {
>> -      kact.k_sa_handler = act->sa_handler;
>> -      memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
>> -      kact.sa_flags = act->sa_flags | SA_RESTORER;
>> -
>> -      kact.sa_restorer = &restore_rt;
>> -    }
>> -
>> -  /* XXX The size argument hopefully will have to be changed to the
>> -     real size of the user-level sigset_t.  */
>> -  result = INLINE_SYSCALL (rt_sigaction, 4,
>> -			   sig, act ? &kact : NULL,
>> -			   oact ? &koact : NULL, _NSIG / 8);
>> -  if (oact && result >= 0)
>> -    {
>> -      oact->sa_handler = koact.k_sa_handler;
>> -      memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
>> -      oact->sa_flags = koact.sa_flags;
>> -      oact->sa_restorer = koact.sa_restorer;
>> -    }
>> -  return result;
>> -}
>> -libc_hidden_def (__libc_sigaction)
>> -
>> -#include <nptl/sigaction.c>
>> +#define RESET_SA_RESTORER(act, kact) 			\
>> +  (act)->sa_restorer = (kact)->sa_restorer
>>  
>> +#include <sysdeps/unix/sysv/linux/sigaction.c>
>>  
>>  /* NOTE: Please think twice before making any changes to the bits of
>>     code below.  GDB needs some intimate knowledge about it to
>> @@ -93,6 +48,8 @@ libc_hidden_def (__libc_sigaction)
>>     a bit tricky.  We don't use the gas cfi directives, so that we can
>>     reliably add .cfi_signal_frame.  */
>>  
>> +#include "ucontext_i.h"
>> +
>>  #define do_cfa_expr						\
>>    "	.byte 0x0f\n"		/* DW_CFA_def_cfa_expression */	\
>>    "	.uleb128 2f-1f\n"	/* length */			\
>>