/* Internal header file for <setjmp.h>.  Linux/x86 version.

   Copyright (C) 2017-2018 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	_SETJMPP_H

#define	_SETJMPP_H	1

#include <bits/types/__sigset_t.h>

#include <libc-pointer-arith.h>

/* <setjmp/setjmp.h> has

struct __jmp_buf_tag

  {

    __jmp_buf __jmpbuf;

    int __mask_was_saved;

    __sigset_t __saved_mask;

  };

   struct __jmp_buf_tag is 32 bits aligned on i386 and is 64 bits

   aligned on x32 and x86-64.  __saved_mask is aligned to 32 bits

   on i386/x32 without padding and is aligned to 64 bits on x86-64

   with 32 bit padding.

   and <nptl/descr.h> has

struct pthread_unwind_buf

{

  struct

  {

    __jmp_buf jmp_buf;

    int mask_was_saved;

  } cancel_jmp_buf[1];

  union

  {

    void *pad[4];

    struct

    {

      struct pthread_unwind_buf *prev;

      struct _pthread_cleanup_buffer *cleanup;

      int canceltype;

    } data;

  } priv;

};

   struct pthread_unwind_buf is 32 bits aligned on i386 and 64 bits

   aligned on x32/x86-64.  cancel_jmp_buf is aligned to 32 bits on

   i386 and is aligned to 64 bits on x32/x86-64.

   The pad array in struct pthread_unwind_buf is used by setjmp to save

   shadow stack register.  The usable space in __saved_mask for sigset

   and shadow stack pointer:

   1. i386: The 4x4 byte pad array which can be used for 4 byte shadow

   stack pointer and maximum 12 byte sigset.

   2. x32: 4 byte padding + the 4x4 byte pad array which can be used

   for 8 byte shadow stack pointer and maximum 12 byte sigset.

   3. x86-64: The 4x8 byte pad array which can be used for 8 byte

   shadow stack pointer and maximum 24 byte sigset.

   NB: We use setjmp in thread cancellation and this saves the shadow

   stack register, but __libc_unwind_longjmp doesn't restore the shadow

   stack register since cancellation never returns after longjmp.  */

/* Number of bits per long.  */

#define _JUMP_BUF_SIGSET_BITS_PER_WORD (8 * sizeof (unsigned long int))

/* The biggest signal number.  As of kernel 4.14, x86 _NSIG is 64. The

   common maximum sigset for i386, x32 and x86-64 is 12 bytes (96 bits).

   Define it to 96 to leave some rooms for future use.  */

#define _JUMP_BUF_SIGSET_NSIG	96

/* Number of longs to hold all signals.  */

#define _JUMP_BUF_SIGSET_NWORDS \

  (ALIGN_UP (_JUMP_BUF_SIGSET_NSIG, _JUMP_BUF_SIGSET_BITS_PER_WORD) \

   / _JUMP_BUF_SIGSET_BITS_PER_WORD)

typedef struct

  {

    unsigned long int __val[_JUMP_BUF_SIGSET_NWORDS];

  } __jmp_buf_sigset_t;

typedef union

  {

    __sigset_t __saved_mask_compat;

    struct

      {

	__jmp_buf_sigset_t __saved_mask;

	/* Used for shadow stack pointer.  NB: Shadow stack pointer

	   must have the same alignment as __saved_mask.  Otherwise

	   offset of __saved_mask will be changed.  */

	unsigned long int __shadow_stack_pointer;

      } __saved;

  } __jmpbuf_arch_t;

#undef __sigset_t

#define __sigset_t __jmpbuf_arch_t

#include <setjmp.h>

#undef __saved_mask

#define __saved_mask __saved_mask.__saved.__saved_mask

#include <signal.h>

#define _SIGPROCMASK_NSIG_WORDS (_NSIG / (8 * sizeof (unsigned long int)))

typedef struct

  {

    unsigned long int __val[_SIGPROCMASK_NSIG_WORDS];

  } __sigprocmask_sigset_t;

extern jmp_buf ___buf;

extern  __typeof (___buf[0].__saved_mask) ___saved_mask;

_Static_assert (sizeof (___saved_mask) >= sizeof (__sigprocmask_sigset_t),

		"size of ___saved_mask < size of __sigprocmask_sigset_t");

#endif /* setjmpP.h  */