gdb/nat/amd64-linux-siginfo.c - binutils-gdb - Git at Google

 /* Low-level siginfo manipulation for amd64.

    Copyright (C) 2002-2025 Free Software Foundation, Inc.

    This file is part of GDB.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 #include <signal.h>
 #include "amd64-linux-siginfo.h"

 #define GDB_SI_SIZE 128

 /* The types below define the most complete kernel siginfo types known
    for the architecture, independent of the system/libc headers.  They
    are named from a 64-bit kernel's perspective:

    | layout | type                 |
    |--------+----------------------|
    | 64-bit | nat_siginfo_t        |
    | 32-bit | compat_siginfo_t     |
    | x32    | compat_x32_siginfo_t |
 */

 #ifndef __ILP32__

 typedef int nat_int_t;
 typedef unsigned long nat_uptr_t;

 typedef int nat_time_t;
 typedef int nat_timer_t;

 /* For native 64-bit, clock_t in _sigchld is 64-bit.  */
 typedef long nat_clock_t;

 union nat_sigval_t
 {
   nat_int_t sival_int;
   nat_uptr_t sival_ptr;
 };

 struct nat_siginfo_t
 {
   int si_signo;
   int si_errno;
   int si_code;

   union
   {
     int _pad[((128 / sizeof (int)) - 4)];
     /* kill() */
     struct
     {
       unsigned int _pid;
       unsigned int _uid;
     } _kill;

     /* POSIX.1b timers */
     struct
     {
       nat_timer_t _tid;
       int _overrun;
       nat_sigval_t _sigval;
     } _timer;

     /* POSIX.1b signals */
     struct
     {
       unsigned int _pid;
       unsigned int _uid;
       nat_sigval_t _sigval;
     } _rt;

     /* SIGCHLD */
     struct
     {
       unsigned int _pid;
       unsigned int _uid;
       int _status;
       nat_clock_t _utime;
       nat_clock_t _stime;
     } _sigchld;

     /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
     struct
     {
       nat_uptr_t _addr;
       short int _addr_lsb;
       struct
       {
 	nat_uptr_t _lower;
 	nat_uptr_t _upper;
       } si_addr_bnd;
     } _sigfault;

     /* SIGPOLL */
     struct
     {
       int _band;
       int _fd;
     } _sigpoll;
   } _sifields;
 };

 #endif /* __ILP32__ */

 /* These types below (compat_*) define a siginfo type that is layout
    compatible with the siginfo type exported by the 32-bit userspace
    support.  */

 typedef int compat_int_t;
 typedef unsigned int compat_uptr_t;

 typedef int compat_time_t;
 typedef int compat_timer_t;
 typedef int compat_clock_t;

 struct compat_timeval
 {
   compat_time_t tv_sec;
   int tv_usec;
 };

 union compat_sigval_t
 {
   compat_int_t sival_int;
   compat_uptr_t sival_ptr;
 };

 struct compat_siginfo_t
 {
   int si_signo;
   int si_errno;
   int si_code;

   union
   {
     int _pad[((128 / sizeof (int)) - 3)];

     /* kill() */
     struct
     {
       unsigned int _pid;
       unsigned int _uid;
     } _kill;

     /* POSIX.1b timers */
     struct
     {
       compat_timer_t _tid;
       int _overrun;
       compat_sigval_t _sigval;
     } _timer;

     /* POSIX.1b signals */
     struct
     {
       unsigned int _pid;
       unsigned int _uid;
       compat_sigval_t _sigval;
     } _rt;

     /* SIGCHLD */
     struct
     {
       unsigned int _pid;
       unsigned int _uid;
       int _status;
       compat_clock_t _utime;
       compat_clock_t _stime;
     } _sigchld;

     /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
     struct
     {
       unsigned int _addr;
       short int _addr_lsb;
       struct
       {
 	unsigned int _lower;
 	unsigned int _upper;
       } si_addr_bnd;
     } _sigfault;

     /* SIGPOLL */
     struct
     {
       int _band;
       int _fd;
     } _sigpoll;
   } _sifields;
 };

 /* For x32, clock_t in _sigchld is 64bit aligned at 4 bytes.  */
 typedef long __attribute__ ((__aligned__ (4))) compat_x32_clock_t;

 struct __attribute__ ((__aligned__ (8))) compat_x32_siginfo_t
 {
   int si_signo;
   int si_errno;
   int si_code;

   union
   {
     int _pad[((128 / sizeof (int)) - 3)];

     /* kill() */
     struct
     {
       unsigned int _pid;
       unsigned int _uid;
     } _kill;

     /* POSIX.1b timers */
     struct
     {
       compat_timer_t _tid;
       int _overrun;
       compat_sigval_t _sigval;
     } _timer;

     /* POSIX.1b signals */
     struct
     {
       unsigned int _pid;
       unsigned int _uid;
       compat_sigval_t _sigval;
     } _rt;

     /* SIGCHLD */
     struct
     {
       unsigned int _pid;
       unsigned int _uid;
       int _status;
       compat_x32_clock_t _utime;
       compat_x32_clock_t _stime;
     } _sigchld;

     /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
     struct
     {
       unsigned int _addr;
       unsigned int _addr_lsb;
     } _sigfault;

     /* SIGPOLL */
     struct
     {
       int _band;
       int _fd;
     } _sigpoll;
   } _sifields;
 };

 /* To simplify usage of siginfo fields.  */

 #define cpt_si_pid _sifields._kill._pid
 #define cpt_si_uid _sifields._kill._uid
 #define cpt_si_timerid _sifields._timer._tid
 #define cpt_si_overrun _sifields._timer._overrun
 #define cpt_si_status _sifields._sigchld._status
 #define cpt_si_utime _sifields._sigchld._utime
 #define cpt_si_stime _sifields._sigchld._stime
 #define cpt_si_ptr _sifields._rt._sigval.sival_ptr
 #define cpt_si_addr _sifields._sigfault._addr
 #define cpt_si_addr_lsb _sifields._sigfault._addr_lsb
 #define cpt_si_lower _sifields._sigfault.si_addr_bnd._lower
 #define cpt_si_upper _sifields._sigfault.si_addr_bnd._upper
 #define cpt_si_band _sifields._sigpoll._band
 #define cpt_si_fd _sifields._sigpoll._fd

 /* glibc at least up to 2.3.2 doesn't have si_timerid, si_overrun.
    In their place is si_timer1,si_timer2.  */

 #ifndef si_timerid
 #define si_timerid si_timer1
 #endif
 #ifndef si_overrun
 #define si_overrun si_timer2
 #endif

 #ifndef SEGV_BNDERR
 #define SEGV_BNDERR	3
 #endif

 /* The type of the siginfo object the kernel returns in
    PTRACE_GETSIGINFO.  If gdb is built as a x32 program, we get a x32
    siginfo.  */
 #ifdef __ILP32__
 typedef compat_x32_siginfo_t ptrace_siginfo_t;
 #else
 typedef nat_siginfo_t ptrace_siginfo_t;
 #endif

 /*  Convert the system provided siginfo into compatible siginfo.  */

 static void
 compat_siginfo_from_siginfo (compat_siginfo_t *to, const siginfo_t *from)
 {
   ptrace_siginfo_t from_ptrace;

   memcpy (&from_ptrace, from, sizeof (from_ptrace));
   memset (to, 0, sizeof (*to));

   to->si_signo = from_ptrace.si_signo;
   to->si_errno = from_ptrace.si_errno;
   to->si_code = from_ptrace.si_code;

   if (to->si_code == SI_TIMER)
     {
       to->cpt_si_timerid = from_ptrace.cpt_si_timerid;
       to->cpt_si_overrun = from_ptrace.cpt_si_overrun;
       to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
     }
   else if (to->si_code == SI_USER)
     {
       to->cpt_si_pid = from_ptrace.cpt_si_pid;
       to->cpt_si_uid = from_ptrace.cpt_si_uid;
     }
 #ifndef __ILP32__
   /* The struct compat_x32_siginfo_t doesn't contain
      cpt_si_lower/cpt_si_upper.  */
   else if (to->si_code == SEGV_BNDERR
 	   && to->si_signo == SIGSEGV)
     {
       to->cpt_si_addr = from_ptrace.cpt_si_addr;
       to->cpt_si_lower = from_ptrace.cpt_si_lower;
       to->cpt_si_upper = from_ptrace.cpt_si_upper;
     }
 #endif
   else if (to->si_code < 0)
     {
       to->cpt_si_pid = from_ptrace.cpt_si_pid;
       to->cpt_si_uid = from_ptrace.cpt_si_uid;
       to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
     }
   else
     {
       switch (to->si_signo)
 	{
 	case SIGCHLD:
 	  to->cpt_si_pid = from_ptrace.cpt_si_pid;
 	  to->cpt_si_uid = from_ptrace.cpt_si_uid;
 	  to->cpt_si_status = from_ptrace.cpt_si_status;
 	  to->cpt_si_utime = from_ptrace.cpt_si_utime;
 	  to->cpt_si_stime = from_ptrace.cpt_si_stime;
 	  break;
 	case SIGILL:
 	case SIGFPE:
 	case SIGSEGV:
 	case SIGBUS:
 	  to->cpt_si_addr = from_ptrace.cpt_si_addr;
 	  break;
 	case SIGPOLL:
 	  to->cpt_si_band = from_ptrace.cpt_si_band;
 	  to->cpt_si_fd = from_ptrace.cpt_si_fd;
 	  break;
 	default:
 	  to->cpt_si_pid = from_ptrace.cpt_si_pid;
 	  to->cpt_si_uid = from_ptrace.cpt_si_uid;
 	  to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
 	  break;
 	}
     }
 }

 /* Convert the compatible siginfo into system siginfo.  */

 static void
 siginfo_from_compat_siginfo (siginfo_t *to, const compat_siginfo_t *from)
 {
   ptrace_siginfo_t to_ptrace;

   memset (&to_ptrace, 0, sizeof (to_ptrace));

   to_ptrace.si_signo = from->si_signo;
   to_ptrace.si_errno = from->si_errno;
   to_ptrace.si_code = from->si_code;

   if (to_ptrace.si_code == SI_TIMER)
     {
       to_ptrace.cpt_si_timerid = from->cpt_si_timerid;
       to_ptrace.cpt_si_overrun = from->cpt_si_overrun;
       to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
     }
   else if (to_ptrace.si_code == SI_USER)
     {
       to_ptrace.cpt_si_pid = from->cpt_si_pid;
       to_ptrace.cpt_si_uid = from->cpt_si_uid;
     }
   if (to_ptrace.si_code < 0)
     {
       to_ptrace.cpt_si_pid = from->cpt_si_pid;
       to_ptrace.cpt_si_uid = from->cpt_si_uid;
       to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
     }
   else
     {
       switch (to_ptrace.si_signo)
 	{
 	case SIGCHLD:
 	  to_ptrace.cpt_si_pid = from->cpt_si_pid;
 	  to_ptrace.cpt_si_uid = from->cpt_si_uid;
 	  to_ptrace.cpt_si_status = from->cpt_si_status;
 	  to_ptrace.cpt_si_utime = from->cpt_si_utime;
 	  to_ptrace.cpt_si_stime = from->cpt_si_stime;
 	  break;
 	case SIGILL:
 	case SIGFPE:
 	case SIGSEGV:
 	case SIGBUS:
 	  to_ptrace.cpt_si_addr = from->cpt_si_addr;
 	  to_ptrace.cpt_si_addr_lsb = from->cpt_si_addr_lsb;
 	  break;
 	case SIGPOLL:
 	  to_ptrace.cpt_si_band = from->cpt_si_band;
 	  to_ptrace.cpt_si_fd = from->cpt_si_fd;
 	  break;
 	default:
 	  to_ptrace.cpt_si_pid = from->cpt_si_pid;
 	  to_ptrace.cpt_si_uid = from->cpt_si_uid;
 	  to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
 	  break;
 	}
     }
   memcpy (to, &to_ptrace, sizeof (to_ptrace));
 }

 /*  Convert the system provided siginfo into compatible x32 siginfo.  */

 static void
 compat_x32_siginfo_from_siginfo (compat_x32_siginfo_t *to,
 				 const siginfo_t *from)
 {
   ptrace_siginfo_t from_ptrace;

   memcpy (&from_ptrace, from, sizeof (from_ptrace));
   memset (to, 0, sizeof (*to));

   to->si_signo = from_ptrace.si_signo;
   to->si_errno = from_ptrace.si_errno;
   to->si_code = from_ptrace.si_code;

   if (to->si_code == SI_TIMER)
     {
       to->cpt_si_timerid = from_ptrace.cpt_si_timerid;
       to->cpt_si_overrun = from_ptrace.cpt_si_overrun;
       to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
     }
   else if (to->si_code == SI_USER)
     {
       to->cpt_si_pid = from_ptrace.cpt_si_pid;
       to->cpt_si_uid = from_ptrace.cpt_si_uid;
     }
   else if (to->si_code < 0)
     {
       to->cpt_si_pid = from_ptrace.cpt_si_pid;
       to->cpt_si_uid = from_ptrace.cpt_si_uid;
       to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
     }
   else
     {
       switch (to->si_signo)
 	{
 	case SIGCHLD:
 	  to->cpt_si_pid = from_ptrace.cpt_si_pid;
 	  to->cpt_si_uid = from_ptrace.cpt_si_uid;
 	  to->cpt_si_status = from_ptrace.cpt_si_status;
 	  memcpy (&to->cpt_si_utime, &from_ptrace.cpt_si_utime,
 		  sizeof (to->cpt_si_utime));
 	  memcpy (&to->cpt_si_stime, &from_ptrace.cpt_si_stime,
 		  sizeof (to->cpt_si_stime));
 	  break;
 	case SIGILL:
 	case SIGFPE:
 	case SIGSEGV:
 	case SIGBUS:
 	  to->cpt_si_addr = from_ptrace.cpt_si_addr;
 	  break;
 	case SIGPOLL:
 	  to->cpt_si_band = from_ptrace.cpt_si_band;
 	  to->cpt_si_fd = from_ptrace.cpt_si_fd;
 	  break;
 	default:
 	  to->cpt_si_pid = from_ptrace.cpt_si_pid;
 	  to->cpt_si_uid = from_ptrace.cpt_si_uid;
 	  to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
 	  break;
 	}
     }
 }


 /* Convert the compatible x32 siginfo into system siginfo.  */
 static void
 siginfo_from_compat_x32_siginfo (siginfo_t *to,
 				 const compat_x32_siginfo_t *from)
 {
   ptrace_siginfo_t to_ptrace;

   memset (&to_ptrace, 0, sizeof (to_ptrace));
   to_ptrace.si_signo = from->si_signo;
   to_ptrace.si_errno = from->si_errno;
   to_ptrace.si_code = from->si_code;

   if (to_ptrace.si_code == SI_TIMER)
     {
       to_ptrace.cpt_si_timerid = from->cpt_si_timerid;
       to_ptrace.cpt_si_overrun = from->cpt_si_overrun;
       to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
     }
   else if (to_ptrace.si_code == SI_USER)
     {
       to_ptrace.cpt_si_pid = from->cpt_si_pid;
       to_ptrace.cpt_si_uid = from->cpt_si_uid;
     }
   if (to_ptrace.si_code < 0)
     {
       to_ptrace.cpt_si_pid = from->cpt_si_pid;
       to_ptrace.cpt_si_uid = from->cpt_si_uid;
       to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
     }
   else
     {
       switch (to_ptrace.si_signo)
 	{
 	case SIGCHLD:
 	  to_ptrace.cpt_si_pid = from->cpt_si_pid;
 	  to_ptrace.cpt_si_uid = from->cpt_si_uid;
 	  to_ptrace.cpt_si_status = from->cpt_si_status;
 	  memcpy (&to_ptrace.cpt_si_utime, &from->cpt_si_utime,
 		  sizeof (to_ptrace.cpt_si_utime));
 	  memcpy (&to_ptrace.cpt_si_stime, &from->cpt_si_stime,
 		  sizeof (to_ptrace.cpt_si_stime));
 	  break;
 	case SIGILL:
 	case SIGFPE:
 	case SIGSEGV:
 	case SIGBUS:
 	  to_ptrace.cpt_si_addr = from->cpt_si_addr;
 	  break;
 	case SIGPOLL:
 	  to_ptrace.cpt_si_band = from->cpt_si_band;
 	  to_ptrace.cpt_si_fd = from->cpt_si_fd;
 	  break;
 	default:
 	  to_ptrace.cpt_si_pid = from->cpt_si_pid;
 	  to_ptrace.cpt_si_uid = from->cpt_si_uid;
 	  to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
 	  break;
 	}
     }
   memcpy (to, &to_ptrace, sizeof (to_ptrace));
 }

 /* Convert a ptrace siginfo object, into/from the siginfo in the
    layout of the inferiors' architecture.  Returns true if any
    conversion was done; false otherwise.  If DIRECTION is 1, then copy
    from INF to PTRACE.  If DIRECTION is 0, then copy from NATIVE to
    INF.  */

 int
 amd64_linux_siginfo_fixup_common (siginfo_t *ptrace, gdb_byte *inf,
 				  int direction,
 				  enum amd64_siginfo_fixup_mode mode)
 {
   if (mode == FIXUP_32)
     {
       if (direction == 0)
 	compat_siginfo_from_siginfo ((compat_siginfo_t *) inf, ptrace);
       else
 	siginfo_from_compat_siginfo (ptrace, (compat_siginfo_t *) inf);

       return 1;
     }
   else if (mode == FIXUP_X32)
     {
       if (direction == 0)
 	compat_x32_siginfo_from_siginfo ((compat_x32_siginfo_t *) inf,
 					 ptrace);
       else
 	siginfo_from_compat_x32_siginfo (ptrace,
 					 (compat_x32_siginfo_t *) inf);

       return 1;
     }
   return 0;
 }

 /* Sanity check for the siginfo structure sizes.  */

 static_assert (sizeof (siginfo_t) == GDB_SI_SIZE);
 #ifndef __ILP32__
 static_assert (sizeof (nat_siginfo_t) == GDB_SI_SIZE);
 #endif
 static_assert (sizeof (compat_x32_siginfo_t) == GDB_SI_SIZE);
 static_assert (sizeof (compat_siginfo_t) == GDB_SI_SIZE);
 static_assert (sizeof (ptrace_siginfo_t) == GDB_SI_SIZE);
	/* Low-level siginfo manipulation for amd64.

	Copyright (C) 2002-2025 Free Software Foundation, Inc.

	This file is part of GDB.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 3 of the License, or
	(at your option) any later version.

	This program 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 General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program. If not, see <http://www.gnu.org/licenses/>. */

	#include <signal.h>
	#include "amd64-linux-siginfo.h"

	#define GDB_SI_SIZE 128

	/* The types below define the most complete kernel siginfo types known
	for the architecture, independent of the system/libc headers. They
	are named from a 64-bit kernel's perspective:

	\| layout \| type \|
	\|--------+----------------------\|
	\| 64-bit \| nat_siginfo_t \|
	\| 32-bit \| compat_siginfo_t \|
	\| x32 \| compat_x32_siginfo_t \|
	*/

	#ifndef __ILP32__

	typedef int nat_int_t;
	typedef unsigned long nat_uptr_t;

	typedef int nat_time_t;
	typedef int nat_timer_t;

	/* For native 64-bit, clock_t in _sigchld is 64-bit. */
	typedef long nat_clock_t;

	union nat_sigval_t
	{
	nat_int_t sival_int;
	nat_uptr_t sival_ptr;
	};

	struct nat_siginfo_t
	{
	int si_signo;
	int si_errno;
	int si_code;

	union
	{
	int _pad[((128 / sizeof (int)) - 4)];
	/* kill() */
	struct
	{
	unsigned int _pid;
	unsigned int _uid;
	} _kill;

	/* POSIX.1b timers */
	struct
	{
	nat_timer_t _tid;
	int _overrun;
	nat_sigval_t _sigval;
	} _timer;

	/* POSIX.1b signals */
	struct
	{
	unsigned int _pid;
	unsigned int _uid;
	nat_sigval_t _sigval;
	} _rt;

	/* SIGCHLD */
	struct
	{
	unsigned int _pid;
	unsigned int _uid;
	int _status;
	nat_clock_t _utime;
	nat_clock_t _stime;
	} _sigchld;

	/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
	struct
	{
	nat_uptr_t _addr;
	short int _addr_lsb;
	struct
	{
	nat_uptr_t _lower;
	nat_uptr_t _upper;
	} si_addr_bnd;
	} _sigfault;

	/* SIGPOLL */
	struct
	{
	int _band;
	int _fd;
	} _sigpoll;
	} _sifields;
	};

	#endif /* __ILP32__ */

	/* These types below (compat_*) define a siginfo type that is layout
	compatible with the siginfo type exported by the 32-bit userspace
	support. */

	typedef int compat_int_t;
	typedef unsigned int compat_uptr_t;

	typedef int compat_time_t;
	typedef int compat_timer_t;
	typedef int compat_clock_t;

	struct compat_timeval
	{
	compat_time_t tv_sec;
	int tv_usec;
	};

	union compat_sigval_t
	{
	compat_int_t sival_int;
	compat_uptr_t sival_ptr;
	};

	struct compat_siginfo_t
	{
	int si_signo;
	int si_errno;
	int si_code;

	union
	{
	int _pad[((128 / sizeof (int)) - 3)];

	/* kill() */
	struct
	{
	unsigned int _pid;
	unsigned int _uid;
	} _kill;

	/* POSIX.1b timers */
	struct
	{
	compat_timer_t _tid;
	int _overrun;
	compat_sigval_t _sigval;
	} _timer;

	/* POSIX.1b signals */
	struct
	{
	unsigned int _pid;
	unsigned int _uid;
	compat_sigval_t _sigval;
	} _rt;

	/* SIGCHLD */
	struct
	{
	unsigned int _pid;
	unsigned int _uid;
	int _status;
	compat_clock_t _utime;
	compat_clock_t _stime;
	} _sigchld;

	/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
	struct
	{
	unsigned int _addr;
	short int _addr_lsb;
	struct
	{
	unsigned int _lower;
	unsigned int _upper;
	} si_addr_bnd;
	} _sigfault;

	/* SIGPOLL */
	struct
	{
	int _band;
	int _fd;
	} _sigpoll;
	} _sifields;
	};

	/* For x32, clock_t in _sigchld is 64bit aligned at 4 bytes. */
	typedef long __attribute__ ((__aligned__ (4))) compat_x32_clock_t;

	struct __attribute__ ((__aligned__ (8))) compat_x32_siginfo_t
	{
	int si_signo;
	int si_errno;
	int si_code;

	union
	{
	int _pad[((128 / sizeof (int)) - 3)];

	/* kill() */
	struct
	{
	unsigned int _pid;
	unsigned int _uid;
	} _kill;

	/* POSIX.1b timers */
	struct
	{
	compat_timer_t _tid;
	int _overrun;
	compat_sigval_t _sigval;
	} _timer;

	/* POSIX.1b signals */
	struct
	{
	unsigned int _pid;
	unsigned int _uid;
	compat_sigval_t _sigval;
	} _rt;

	/* SIGCHLD */
	struct
	{
	unsigned int _pid;
	unsigned int _uid;
	int _status;
	compat_x32_clock_t _utime;
	compat_x32_clock_t _stime;
	} _sigchld;

	/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
	struct
	{
	unsigned int _addr;
	unsigned int _addr_lsb;
	} _sigfault;

	/* SIGPOLL */
	struct
	{
	int _band;
	int _fd;
	} _sigpoll;
	} _sifields;
	};

	/* To simplify usage of siginfo fields. */

	#define cpt_si_pid _sifields._kill._pid
	#define cpt_si_uid _sifields._kill._uid
	#define cpt_si_timerid _sifields._timer._tid
	#define cpt_si_overrun _sifields._timer._overrun
	#define cpt_si_status _sifields._sigchld._status
	#define cpt_si_utime _sifields._sigchld._utime
	#define cpt_si_stime _sifields._sigchld._stime
	#define cpt_si_ptr _sifields._rt._sigval.sival_ptr
	#define cpt_si_addr _sifields._sigfault._addr
	#define cpt_si_addr_lsb _sifields._sigfault._addr_lsb
	#define cpt_si_lower _sifields._sigfault.si_addr_bnd._lower
	#define cpt_si_upper _sifields._sigfault.si_addr_bnd._upper
	#define cpt_si_band _sifields._sigpoll._band
	#define cpt_si_fd _sifields._sigpoll._fd

	/* glibc at least up to 2.3.2 doesn't have si_timerid, si_overrun.
	In their place is si_timer1,si_timer2. */

	#ifndef si_timerid
	#define si_timerid si_timer1
	#endif
	#ifndef si_overrun
	#define si_overrun si_timer2
	#endif

	#ifndef SEGV_BNDERR
	#define SEGV_BNDERR 3
	#endif

	/* The type of the siginfo object the kernel returns in
	PTRACE_GETSIGINFO. If gdb is built as a x32 program, we get a x32
	siginfo. */
	#ifdef __ILP32__
	typedef compat_x32_siginfo_t ptrace_siginfo_t;
	#else
	typedef nat_siginfo_t ptrace_siginfo_t;
	#endif

	/* Convert the system provided siginfo into compatible siginfo. */

	static void
	compat_siginfo_from_siginfo (compat_siginfo_t to, const siginfo_t from)
	{
	ptrace_siginfo_t from_ptrace;

	memcpy (&from_ptrace, from, sizeof (from_ptrace));
	memset (to, 0, sizeof (*to));

	to->si_signo = from_ptrace.si_signo;
	to->si_errno = from_ptrace.si_errno;
	to->si_code = from_ptrace.si_code;

	if (to->si_code == SI_TIMER)
	{
	to->cpt_si_timerid = from_ptrace.cpt_si_timerid;
	to->cpt_si_overrun = from_ptrace.cpt_si_overrun;
	to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
	}
	else if (to->si_code == SI_USER)
	{
	to->cpt_si_pid = from_ptrace.cpt_si_pid;
	to->cpt_si_uid = from_ptrace.cpt_si_uid;
	}
	#ifndef __ILP32__
	/* The struct compat_x32_siginfo_t doesn't contain
	cpt_si_lower/cpt_si_upper. */
	else if (to->si_code == SEGV_BNDERR
	&& to->si_signo == SIGSEGV)
	{
	to->cpt_si_addr = from_ptrace.cpt_si_addr;
	to->cpt_si_lower = from_ptrace.cpt_si_lower;
	to->cpt_si_upper = from_ptrace.cpt_si_upper;
	}
	#endif
	else if (to->si_code < 0)
	{
	to->cpt_si_pid = from_ptrace.cpt_si_pid;
	to->cpt_si_uid = from_ptrace.cpt_si_uid;
	to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
	}
	else
	{
	switch (to->si_signo)
	{
	case SIGCHLD:
	to->cpt_si_pid = from_ptrace.cpt_si_pid;
	to->cpt_si_uid = from_ptrace.cpt_si_uid;
	to->cpt_si_status = from_ptrace.cpt_si_status;
	to->cpt_si_utime = from_ptrace.cpt_si_utime;
	to->cpt_si_stime = from_ptrace.cpt_si_stime;
	break;
	case SIGILL:
	case SIGFPE:
	case SIGSEGV:
	case SIGBUS:
	to->cpt_si_addr = from_ptrace.cpt_si_addr;
	break;
	case SIGPOLL:
	to->cpt_si_band = from_ptrace.cpt_si_band;
	to->cpt_si_fd = from_ptrace.cpt_si_fd;
	break;
	default:
	to->cpt_si_pid = from_ptrace.cpt_si_pid;
	to->cpt_si_uid = from_ptrace.cpt_si_uid;
	to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
	break;
	}
	}
	}

	/* Convert the compatible siginfo into system siginfo. */

	static void
	siginfo_from_compat_siginfo (siginfo_t to, const compat_siginfo_t from)
	{
	ptrace_siginfo_t to_ptrace;

	memset (&to_ptrace, 0, sizeof (to_ptrace));

	to_ptrace.si_signo = from->si_signo;
	to_ptrace.si_errno = from->si_errno;
	to_ptrace.si_code = from->si_code;

	if (to_ptrace.si_code == SI_TIMER)
	{
	to_ptrace.cpt_si_timerid = from->cpt_si_timerid;
	to_ptrace.cpt_si_overrun = from->cpt_si_overrun;
	to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
	}
	else if (to_ptrace.si_code == SI_USER)
	{
	to_ptrace.cpt_si_pid = from->cpt_si_pid;
	to_ptrace.cpt_si_uid = from->cpt_si_uid;
	}
	if (to_ptrace.si_code < 0)
	{
	to_ptrace.cpt_si_pid = from->cpt_si_pid;
	to_ptrace.cpt_si_uid = from->cpt_si_uid;
	to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
	}
	else
	{
	switch (to_ptrace.si_signo)
	{
	case SIGCHLD:
	to_ptrace.cpt_si_pid = from->cpt_si_pid;
	to_ptrace.cpt_si_uid = from->cpt_si_uid;
	to_ptrace.cpt_si_status = from->cpt_si_status;
	to_ptrace.cpt_si_utime = from->cpt_si_utime;
	to_ptrace.cpt_si_stime = from->cpt_si_stime;
	break;
	case SIGILL:
	case SIGFPE:
	case SIGSEGV:
	case SIGBUS:
	to_ptrace.cpt_si_addr = from->cpt_si_addr;
	to_ptrace.cpt_si_addr_lsb = from->cpt_si_addr_lsb;
	break;
	case SIGPOLL:
	to_ptrace.cpt_si_band = from->cpt_si_band;
	to_ptrace.cpt_si_fd = from->cpt_si_fd;
	break;
	default:
	to_ptrace.cpt_si_pid = from->cpt_si_pid;
	to_ptrace.cpt_si_uid = from->cpt_si_uid;
	to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
	break;
	}
	}
	memcpy (to, &to_ptrace, sizeof (to_ptrace));
	}

	/* Convert the system provided siginfo into compatible x32 siginfo. */

	static void
	compat_x32_siginfo_from_siginfo (compat_x32_siginfo_t *to,
	const siginfo_t *from)
	{
	ptrace_siginfo_t from_ptrace;

	memcpy (&from_ptrace, from, sizeof (from_ptrace));
	memset (to, 0, sizeof (*to));

	to->si_signo = from_ptrace.si_signo;
	to->si_errno = from_ptrace.si_errno;
	to->si_code = from_ptrace.si_code;

	if (to->si_code == SI_TIMER)
	{
	to->cpt_si_timerid = from_ptrace.cpt_si_timerid;
	to->cpt_si_overrun = from_ptrace.cpt_si_overrun;
	to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
	}
	else if (to->si_code == SI_USER)
	{
	to->cpt_si_pid = from_ptrace.cpt_si_pid;
	to->cpt_si_uid = from_ptrace.cpt_si_uid;
	}
	else if (to->si_code < 0)
	{
	to->cpt_si_pid = from_ptrace.cpt_si_pid;
	to->cpt_si_uid = from_ptrace.cpt_si_uid;
	to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
	}
	else
	{
	switch (to->si_signo)
	{
	case SIGCHLD:
	to->cpt_si_pid = from_ptrace.cpt_si_pid;
	to->cpt_si_uid = from_ptrace.cpt_si_uid;
	to->cpt_si_status = from_ptrace.cpt_si_status;
	memcpy (&to->cpt_si_utime, &from_ptrace.cpt_si_utime,
	sizeof (to->cpt_si_utime));
	memcpy (&to->cpt_si_stime, &from_ptrace.cpt_si_stime,
	sizeof (to->cpt_si_stime));
	break;
	case SIGILL:
	case SIGFPE:
	case SIGSEGV:
	case SIGBUS:
	to->cpt_si_addr = from_ptrace.cpt_si_addr;
	break;
	case SIGPOLL:
	to->cpt_si_band = from_ptrace.cpt_si_band;
	to->cpt_si_fd = from_ptrace.cpt_si_fd;
	break;
	default:
	to->cpt_si_pid = from_ptrace.cpt_si_pid;
	to->cpt_si_uid = from_ptrace.cpt_si_uid;
	to->cpt_si_ptr = from_ptrace.cpt_si_ptr;
	break;
	}
	}
	}




	/* Convert the compatible x32 siginfo into system siginfo. */
	static void
	siginfo_from_compat_x32_siginfo (siginfo_t *to,
	const compat_x32_siginfo_t *from)
	{
	ptrace_siginfo_t to_ptrace;

	memset (&to_ptrace, 0, sizeof (to_ptrace));
	to_ptrace.si_signo = from->si_signo;
	to_ptrace.si_errno = from->si_errno;
	to_ptrace.si_code = from->si_code;

	if (to_ptrace.si_code == SI_TIMER)
	{
	to_ptrace.cpt_si_timerid = from->cpt_si_timerid;
	to_ptrace.cpt_si_overrun = from->cpt_si_overrun;
	to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
	}
	else if (to_ptrace.si_code == SI_USER)
	{
	to_ptrace.cpt_si_pid = from->cpt_si_pid;
	to_ptrace.cpt_si_uid = from->cpt_si_uid;
	}
	if (to_ptrace.si_code < 0)
	{
	to_ptrace.cpt_si_pid = from->cpt_si_pid;
	to_ptrace.cpt_si_uid = from->cpt_si_uid;
	to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
	}
	else
	{
	switch (to_ptrace.si_signo)
	{
	case SIGCHLD:
	to_ptrace.cpt_si_pid = from->cpt_si_pid;
	to_ptrace.cpt_si_uid = from->cpt_si_uid;
	to_ptrace.cpt_si_status = from->cpt_si_status;
	memcpy (&to_ptrace.cpt_si_utime, &from->cpt_si_utime,
	sizeof (to_ptrace.cpt_si_utime));
	memcpy (&to_ptrace.cpt_si_stime, &from->cpt_si_stime,
	sizeof (to_ptrace.cpt_si_stime));
	break;
	case SIGILL:
	case SIGFPE:
	case SIGSEGV:
	case SIGBUS:
	to_ptrace.cpt_si_addr = from->cpt_si_addr;
	break;
	case SIGPOLL:
	to_ptrace.cpt_si_band = from->cpt_si_band;
	to_ptrace.cpt_si_fd = from->cpt_si_fd;
	break;
	default:
	to_ptrace.cpt_si_pid = from->cpt_si_pid;
	to_ptrace.cpt_si_uid = from->cpt_si_uid;
	to_ptrace.cpt_si_ptr = from->cpt_si_ptr;
	break;
	}
	}
	memcpy (to, &to_ptrace, sizeof (to_ptrace));
	}

	/* Convert a ptrace siginfo object, into/from the siginfo in the
	layout of the inferiors' architecture. Returns true if any
	conversion was done; false otherwise. If DIRECTION is 1, then copy
	from INF to PTRACE. If DIRECTION is 0, then copy from NATIVE to
	INF. */

	int
	amd64_linux_siginfo_fixup_common (siginfo_t ptrace, gdb_byte inf,
	int direction,
	enum amd64_siginfo_fixup_mode mode)
	{
	if (mode == FIXUP_32)
	{
	if (direction == 0)
	compat_siginfo_from_siginfo ((compat_siginfo_t *) inf, ptrace);
	else
	siginfo_from_compat_siginfo (ptrace, (compat_siginfo_t *) inf);

	return 1;
	}
	else if (mode == FIXUP_X32)
	{
	if (direction == 0)
	compat_x32_siginfo_from_siginfo ((compat_x32_siginfo_t *) inf,
	ptrace);
	else
	siginfo_from_compat_x32_siginfo (ptrace,
	(compat_x32_siginfo_t *) inf);

	return 1;
	}
	return 0;
	}

	/* Sanity check for the siginfo structure sizes. */

	static_assert (sizeof (siginfo_t) == GDB_SI_SIZE);
	#ifndef __ILP32__
	static_assert (sizeof (nat_siginfo_t) == GDB_SI_SIZE);
	#endif
	static_assert (sizeof (compat_x32_siginfo_t) == GDB_SI_SIZE);
	static_assert (sizeof (compat_siginfo_t) == GDB_SI_SIZE);
	static_assert (sizeof (ptrace_siginfo_t) == GDB_SI_SIZE);