Merge gdb and gdbserver implementations for siginfo

Extract the compatible siginfo handling from amd64-linux-nat.c and
gdbserver/linux-x86-low to a new file nat/amd64-linux-siginfo.c.

2016-02-02  Walfred Tedeschi  <walfred.tedeschi@intel.com>

gdb/ChangeLog:

	* nat/amd64-linux-siginfo.c: New file.
	* nat/amd64-linux-siginfo.h: New file.
	* Makefile.in (HFILES_NO_SRCDIR): Add nat/amd64-linux-siginfo.h.
	(amd64-linux-siginfo.o): New rule.
	* config/i386/linux64.mh (NATDEPFILES): Add amd64-linux-siginfo.o.
	* amd64-linux-nat.c (nat/amd64-linux-siginfo.h): New include.
	(compat_siginfo_from_siginfo, siginfo_from_compat_siginfo)
	(compat_x32_siginfo_from_siginfo, siginfo_from_compat_x32_siginfo)
	(compat_timeval, compat_sigval, compat_x32_clock, cpt_si_pid)
	(cpt_si_uid, cpt_si_timerid, cpt_si_overrun, cpt_si_status)
	(cpt_si_utime, cpt_si_stime, cpt_si_ptr, cpt_si_addr, cpt_si_band)
	(cpt_si_fd, si_timerid, si_overrun): Move to nat/amd64-linux-siginfo.c.

gdb/gdbserver/ChangeLog:

	* configure.srv (x86_64-*-linux*): Add amd64-linux-siginfo.o
	to srv_tgtobj.
	(i[34567]86-*-linux*): Add amd64-linux-siginfo.o
	to srv_tgtobj.
	* linux-x86-low.c [__x86_64__]: Include
	"nat/amd64-linux-siginfo.h".
	(compat_siginfo_from_siginfo, siginfo_from_compat_siginfo)
	(compat_x32_siginfo_from_siginfo, siginfo_from_compat_x32_siginfo)
	(compat_timeval, compat_sigval, compat_x32_clock, cpt_si_pid)
	(cpt_si_uid, cpt_si_timerid, cpt_si_overrun, cpt_si_status)
	(cpt_si_utime, cpt_si_stime, cpt_si_ptr, cpt_si_addr, cpt_si_band)
	(cpt_si_fd, si_timerid, si_overrun): Move from
	nat/amd64-linux-siginfo.c.
	* Makefile.in (amd64-linux-siginfo.o:): New rule.

10 files changed, 563 insertions, 844 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 8a11a17266c..e6346ad4d32 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,18 @@
+2016-02-02  Walfred Tedeschi  <walfred.tedeschi@intel.com>
+
+	* nat/amd64-linux-siginfo.c: New file.
+	* nat/amd64-linux-siginfo.h: New file.
+	* Makefile.in (HFILES_NO_SRCDIR): Add nat/amd64-linux-siginfo.h.
+	(amd64-linux-siginfo.o): New rule.
+	* config/i386/linux64.mh (NATDEPFILES): Add amd64-linux-siginfo.o.
+	* amd64-linux-nat.c (nat/amd64-linux-siginfo.h): New include.
+	(compat_siginfo_from_siginfo, siginfo_from_compat_siginfo)
+	(compat_x32_siginfo_from_siginfo, siginfo_from_compat_x32_siginfo)
+	(compat_timeval, compat_sigval, compat_x32_clock, cpt_si_pid)
+	(cpt_si_uid, cpt_si_timerid, cpt_si_overrun, cpt_si_status)
+	(cpt_si_utime, cpt_si_stime, cpt_si_ptr, cpt_si_addr, cpt_si_band)
+	(cpt_si_fd, si_timerid, si_overrun): Move to nat/amd64-linux-siginfo.c.
+
 2016-02-01  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* value.c (max_value_size): New variable.
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 5e8eb9aa039..ec2af52dc44 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -986,7 +986,7 @@ i386-linux-nat.h common/common-defs.h common/errors.h common/common-types.h \
 common/common-debug.h common/cleanups.h common/gdb_setjmp.h \
 common/common-exceptions.h target/target.h common/symbol.h \
 common/common-regcache.h fbsd-tdep.h nat/linux-personality.h \
-common/fileio.h nat/x86-linux.h nat/x86-linux-dregs.h \
+common/fileio.h nat/x86-linux.h nat/x86-linux-dregs.h nat/amd64-linux-siginfo.h\
 nat/linux-namespaces.h arch/arm.h common/gdb_sys_time.h arch/aarch64-insn.h \
 tid-parse.h
 
@@ -2352,6 +2352,10 @@ x86-linux-dregs.o: ${srcdir}/nat/x86-linux-dregs.c
 	$(COMPILE) $(srcdir)/nat/x86-linux-dregs.c
 	$(POSTCOMPILE)
 
+amd64-linux-siginfo.o: ${srcdir}/nat/amd64-linux-siginfo.c
+	$(COMPILE) $(srcdir)/nat/amd64-linux-siginfo.c
+	$(POSTCOMPILE)
+
 linux-namespaces.o: ${srcdir}/nat/linux-namespaces.c
 	$(COMPILE) $(srcdir)/nat/linux-namespaces.c
 	$(POSTCOMPILE)
diff --git a/gdb/amd64-linux-nat.c b/gdb/amd64-linux-nat.c
index 32cbd468dd4..391a646992b 100644
--- a/gdb/amd64-linux-nat.c
+++ b/gdb/amd64-linux-nat.c
@@ -38,6 +38,7 @@
 
 #include "x86-linux-nat.h"
 #include "nat/linux-ptrace.h"
+#include "nat/amd64-linux-siginfo.h"
 
 /* Mapping between the general-purpose registers in GNU/Linux x86-64
    `struct user' format and GDB's register cache layout for GNU/Linux
@@ -320,409 +321,6 @@ ps_get_thread_area (const struct ps_prochandle *ph,
 }
 
 
-/* When GDB is built as a 64-bit application on linux, the
-   PTRACE_GETSIGINFO data is always presented in 64-bit layout.  Since
-   debugging a 32-bit inferior with a 64-bit GDB should look the same
-   as debugging it with a 32-bit GDB, we do the 32-bit <-> 64-bit
-   conversion in-place ourselves.  */
-
-/* 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;
-};
-
-typedef union compat_sigval
-{
-  compat_int_t sival_int;
-  compat_uptr_t sival_ptr;
-} compat_sigval_t;
-
-typedef struct compat_siginfo
-{
-  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;
-    } _sigfault;
-
-    /* SIGPOLL */
-    struct
-    {
-      int _band;
-      int _fd;
-    } _sigpoll;
-  } _sifields;
-} compat_siginfo_t;
-
-/* For x32, clock_t in _sigchld is 64bit aligned at 4 bytes.  */
-typedef struct compat_x32_clock
-{
-  int lower;
-  int upper;
-} compat_x32_clock_t;
-
-typedef struct compat_x32_siginfo
-{
-  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;
-    } _sigfault;
-
-    /* SIGPOLL */
-    struct
-    {
-      int _band;
-      int _fd;
-    } _sigpoll;
-  } _sifields;
-} compat_x32_siginfo_t;
-
-#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_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
-
-static void
-compat_siginfo_from_siginfo (compat_siginfo_t *to, siginfo_t *from)
-{
-  memset (to, 0, sizeof (*to));
-
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
-
-  if (to->si_code == SI_TIMER)
-    {
-      to->cpt_si_timerid = from->si_timerid;
-      to->cpt_si_overrun = from->si_overrun;
-      to->cpt_si_ptr = (intptr_t) from->si_ptr;
-    }
-  else if (to->si_code == SI_USER)
-    {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
-    }
-  else if (to->si_code < 0)
-    {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
-      to->cpt_si_ptr = (intptr_t) from->si_ptr;
-    }
-  else
-    {
-      switch (to->si_signo)
-	{
-	case SIGCHLD:
-	  to->cpt_si_pid = from->si_pid;
-	  to->cpt_si_uid = from->si_uid;
-	  to->cpt_si_status = from->si_status;
-	  to->cpt_si_utime = from->si_utime;
-	  to->cpt_si_stime = from->si_stime;
-	  break;
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	  to->cpt_si_addr = (intptr_t) from->si_addr;
-	  break;
-	case SIGPOLL:
-	  to->cpt_si_band = from->si_band;
-	  to->cpt_si_fd = from->si_fd;
-	  break;
-	default:
-	  to->cpt_si_pid = from->si_pid;
-	  to->cpt_si_uid = from->si_uid;
-	  to->cpt_si_ptr = (intptr_t) from->si_ptr;
-	  break;
-	}
-    }
-}
-
-static void
-siginfo_from_compat_siginfo (siginfo_t *to, compat_siginfo_t *from)
-{
-  memset (to, 0, sizeof (*to));
-
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
-
-  if (to->si_code == SI_TIMER)
-    {
-      to->si_timerid = from->cpt_si_timerid;
-      to->si_overrun = from->cpt_si_overrun;
-      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
-    }
-  else if (to->si_code == SI_USER)
-    {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
-    }
-  if (to->si_code < 0)
-    {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
-      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
-    }
-  else
-    {
-      switch (to->si_signo)
-	{
-	case SIGCHLD:
-	  to->si_pid = from->cpt_si_pid;
-	  to->si_uid = from->cpt_si_uid;
-	  to->si_status = from->cpt_si_status;
-	  to->si_utime = from->cpt_si_utime;
-	  to->si_stime = from->cpt_si_stime;
-	  break;
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	  to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
-	  break;
-	case SIGPOLL:
-	  to->si_band = from->cpt_si_band;
-	  to->si_fd = from->cpt_si_fd;
-	  break;
-	default:
-	  to->si_pid = from->cpt_si_pid;
-	  to->si_uid = from->cpt_si_uid;
-	  to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
-	  break;
-	}
-    }
-}
-
-static void
-compat_x32_siginfo_from_siginfo (compat_x32_siginfo_t *to,
-				 siginfo_t *from)
-{
-  memset (to, 0, sizeof (*to));
-
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
-
-  if (to->si_code == SI_TIMER)
-    {
-      to->cpt_si_timerid = from->si_timerid;
-      to->cpt_si_overrun = from->si_overrun;
-      to->cpt_si_ptr = (intptr_t) from->si_ptr;
-    }
-  else if (to->si_code == SI_USER)
-    {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
-    }
-  else if (to->si_code < 0)
-    {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
-      to->cpt_si_ptr = (intptr_t) from->si_ptr;
-    }
-  else
-    {
-      switch (to->si_signo)
-	{
-	case SIGCHLD:
-	  to->cpt_si_pid = from->si_pid;
-	  to->cpt_si_uid = from->si_uid;
-	  to->cpt_si_status = from->si_status;
-	  memcpy (&to->cpt_si_utime, &from->si_utime,
-		  sizeof (to->cpt_si_utime));
-	  memcpy (&to->cpt_si_stime, &from->si_stime,
-		  sizeof (to->cpt_si_stime));
-	  break;
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	  to->cpt_si_addr = (intptr_t) from->si_addr;
-	  break;
-	case SIGPOLL:
-	  to->cpt_si_band = from->si_band;
-	  to->cpt_si_fd = from->si_fd;
-	  break;
-	default:
-	  to->cpt_si_pid = from->si_pid;
-	  to->cpt_si_uid = from->si_uid;
-	  to->cpt_si_ptr = (intptr_t) from->si_ptr;
-	  break;
-	}
-    }
-}
-
-static void
-siginfo_from_compat_x32_siginfo (siginfo_t *to,
-				 compat_x32_siginfo_t *from)
-{
-  memset (to, 0, sizeof (*to));
-
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
-
-  if (to->si_code == SI_TIMER)
-    {
-      to->si_timerid = from->cpt_si_timerid;
-      to->si_overrun = from->cpt_si_overrun;
-      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
-    }
-  else if (to->si_code == SI_USER)
-    {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
-    }
-  if (to->si_code < 0)
-    {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
-      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
-    }
-  else
-    {
-      switch (to->si_signo)
-	{
-	case SIGCHLD:
-	  to->si_pid = from->cpt_si_pid;
-	  to->si_uid = from->cpt_si_uid;
-	  to->si_status = from->cpt_si_status;
-	  memcpy (&to->si_utime, &from->cpt_si_utime,
-		  sizeof (to->si_utime));
-	  memcpy (&to->si_stime, &from->cpt_si_stime,
-		  sizeof (to->si_stime));
-	  break;
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	  to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
-	  break;
-	case SIGPOLL:
-	  to->si_band = from->cpt_si_band;
-	  to->si_fd = from->cpt_si_fd;
-	  break;
-	default:
-	  to->si_pid = from->cpt_si_pid;
-	  to->si_uid = from->cpt_si_uid;
-	  to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
-	  break;
-	}
-    }
-}
-
 /* Convert a native/host 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
@@ -737,34 +335,15 @@ amd64_linux_siginfo_fixup (siginfo_t *native, gdb_byte *inf, int direction)
   /* Is the inferior 32-bit?  If so, then do fixup the siginfo
      object.  */
   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
-    {
-      gdb_assert (sizeof (siginfo_t) == sizeof (compat_siginfo_t));
-
-      if (direction == 0)
-	compat_siginfo_from_siginfo ((struct compat_siginfo *) inf, native);
-      else
-	siginfo_from_compat_siginfo (native, (struct compat_siginfo *) inf);
-
-      return 1;
-    }
+      return amd64_linux_siginfo_fixup_common (native, inf, direction,
+					       FIXUP_32);
   /* No fixup for native x32 GDB.  */
   else if (gdbarch_addr_bit (gdbarch) == 32 && sizeof (void *) == 8)
-    {
-      gdb_assert (sizeof (siginfo_t) == sizeof (compat_x32_siginfo_t));
-
-      if (direction == 0)
-	compat_x32_siginfo_from_siginfo ((struct compat_x32_siginfo *) inf,
-					 native);
-      else
-	siginfo_from_compat_x32_siginfo (native,
-					 (struct compat_x32_siginfo *) inf);
-
-      return 1;
-    }
+      return amd64_linux_siginfo_fixup_common (native, inf, direction,
+					       FIXUP_X32);
   else
     return 0;
 }
-
 
 /* Provide a prototype to silence -Wmissing-prototypes.  */
 void _initialize_amd64_linux_nat (void);
diff --git a/gdb/config/i386/linux64.mh b/gdb/config/i386/linux64.mh
index 04cbb95833e..42d8df5913a 100644
--- a/gdb/config/i386/linux64.mh
+++ b/gdb/config/i386/linux64.mh
@@ -6,7 +6,7 @@ NATDEPFILES= inf-ptrace.o fork-child.o \
 	proc-service.o linux-thread-db.o linux-fork.o \
 	linux-procfs.o linux-ptrace.o linux-btrace.o \
 	linux-waitpid.o linux-personality.o x86-linux.o \
-	x86-linux-dregs.o linux-namespaces.o
+	x86-linux-dregs.o amd64-linux-siginfo.o linux-namespaces.o
 NAT_FILE= config/nm-linux.h
 NAT_CDEPS = $(srcdir)/proc-service.list
 
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 1f9c139a7e3..e0da782a0ac 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,20 @@
+2016-02-02  Walfred Tedeschi  <walfred.tedeschi@intel.com>
+
+	* configure.srv (x86_64-*-linux*): Add amd64-linux-siginfo.o
+	to srv_tgtobj.
+	(i[34567]86-*-linux*): Add amd64-linux-siginfo.o
+	to srv_tgtobj.
+	* linux-x86-low.c [__x86_64__]: Include
+	"nat/amd64-linux-siginfo.h".
+	(compat_siginfo_from_siginfo, siginfo_from_compat_siginfo)
+	(compat_x32_siginfo_from_siginfo, siginfo_from_compat_x32_siginfo)
+	(compat_timeval, compat_sigval, compat_x32_clock, cpt_si_pid)
+	(cpt_si_uid, cpt_si_timerid, cpt_si_overrun, cpt_si_status)
+	(cpt_si_utime, cpt_si_stime, cpt_si_ptr, cpt_si_addr, cpt_si_band)
+	(cpt_si_fd, si_timerid, si_overrun): Move from
+	nat/amd64-linux-siginfo.c.
+	* Makefile.in (amd64-linux-siginfo.o:): New rule.
+
 2016-01-28  Simon Marchi  <simon.marchi@ericsson.com>
 
 	* server.c (skip_to_semicolon):  Remove.
diff --git a/gdb/gdbserver/Makefile.in b/gdb/gdbserver/Makefile.in
index f9b9dbe79a3..1e874e39ef1 100644
--- a/gdb/gdbserver/Makefile.in
+++ b/gdb/gdbserver/Makefile.in
@@ -608,6 +608,9 @@ arm-get-next-pcs.o: ../arch/arm-get-next-pcs.c
 x86-dregs.o: ../nat/x86-dregs.c
 	$(COMPILE) $<
 	$(POSTCOMPILE)
+amd64-linux-siginfo.o: ../nat/amd64-linux-siginfo.c
+	$(COMPILE) $<
+	$(POSTCOMPILE)
 linux-btrace.o: ../nat/linux-btrace.c
 	$(COMPILE) $<
 	$(POSTCOMPILE)
diff --git a/gdb/gdbserver/configure.srv b/gdb/gdbserver/configure.srv
index 5f5112e8299..a54b9e79204 100644
--- a/gdb/gdbserver/configure.srv
+++ b/gdb/gdbserver/configure.srv
@@ -118,8 +118,9 @@ case "${target}" in
 			if test "$gdb_cv_i386_is_x86_64" = yes ; then
 			    srv_regobj="$srv_regobj $srv_amd64_linux_regobj"
 			    srv_xmlfiles="${srv_xmlfiles} $srv_amd64_linux_xmlfiles"
+			    srv_tgtobj="amd64-linux-siginfo.o"
 			fi
-			srv_tgtobj="$srv_linux_obj linux-x86-low.o x86-low.o x86-dregs.o i387-fp.o"
+			srv_tgtobj="${srv_tgtobj} $srv_linux_obj linux-x86-low.o x86-low.o x86-dregs.o i387-fp.o"
 			srv_tgtobj="${srv_tgtobj} linux-btrace.o x86-linux.o"
 			srv_tgtobj="${srv_tgtobj} x86-linux-dregs.o"
 			srv_linux_usrregs=yes
@@ -339,6 +340,7 @@ case "${target}" in
 			srv_tgtobj="$srv_linux_obj linux-x86-low.o x86-low.o x86-dregs.o i387-fp.o"
 			srv_tgtobj="${srv_tgtobj} linux-btrace.o x86-linux.o"
 			srv_tgtobj="${srv_tgtobj} x86-linux-dregs.o"
+			srv_tgtobj="${srv_tgtobj} amd64-linux-siginfo.o"
 			srv_xmlfiles="$srv_i386_linux_xmlfiles $srv_amd64_linux_xmlfiles"
 			srv_linux_usrregs=yes # This is for i386 progs.
 			srv_linux_regsets=yes
diff --git a/gdb/gdbserver/linux-x86-low.c b/gdb/gdbserver/linux-x86-low.c
index 4a01750c172..ff51a95357b 100644
--- a/gdb/gdbserver/linux-x86-low.c
+++ b/gdb/gdbserver/linux-x86-low.c
@@ -27,6 +27,10 @@
 #include "x86-xstate.h"
 #include "nat/gdb_ptrace.h"
 
+#ifdef __x86_64__
+#include "nat/amd64-linux-siginfo.h"
+#endif
+
 #include "gdb_proc_service.h"
 /* Don't include elf/common.h if linux/elf.h got included by
    gdb_proc_service.h.  */
@@ -670,399 +674,6 @@ x86_debug_reg_state (pid_t pid)
    as debugging it with a 32-bit GDBSERVER, we do the 32-bit <-> 64-bit
    conversion in-place ourselves.  */
 
-/* These types below (compat_*) define a siginfo type that is layout
-   compatible with the siginfo type exported by the 32-bit userspace
-   support.  */
-
-#ifdef __x86_64__
-
-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;
-};
-
-typedef union compat_sigval
-{
-  compat_int_t sival_int;
-  compat_uptr_t sival_ptr;
-} compat_sigval_t;
-
-typedef struct compat_siginfo
-{
-  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;
-    } _sigfault;
-
-    /* SIGPOLL */
-    struct
-    {
-      int _band;
-      int _fd;
-    } _sigpoll;
-  } _sifields;
-} compat_siginfo_t;
-
-/* For x32, clock_t in _sigchld is 64bit aligned at 4 bytes.  */
-typedef long __attribute__ ((__aligned__ (4))) compat_x32_clock_t;
-
-typedef struct compat_x32_siginfo
-{
-  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;
-    } _sigfault;
-
-    /* SIGPOLL */
-    struct
-    {
-      int _band;
-      int _fd;
-    } _sigpoll;
-  } _sifields;
-} compat_x32_siginfo_t __attribute__ ((__aligned__ (8)));
-
-#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_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
-
-static void
-compat_siginfo_from_siginfo (compat_siginfo_t *to, siginfo_t *from)
-{
-  memset (to, 0, sizeof (*to));
-
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
-
-  if (to->si_code == SI_TIMER)
-    {
-      to->cpt_si_timerid = from->si_timerid;
-      to->cpt_si_overrun = from->si_overrun;
-      to->cpt_si_ptr = (intptr_t) from->si_ptr;
-    }
-  else if (to->si_code == SI_USER)
-    {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
-    }
-  else if (to->si_code < 0)
-    {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
-      to->cpt_si_ptr = (intptr_t) from->si_ptr;
-    }
-  else
-    {
-      switch (to->si_signo)
-	{
-	case SIGCHLD:
-	  to->cpt_si_pid = from->si_pid;
-	  to->cpt_si_uid = from->si_uid;
-	  to->cpt_si_status = from->si_status;
-	  to->cpt_si_utime = from->si_utime;
-	  to->cpt_si_stime = from->si_stime;
-	  break;
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	  to->cpt_si_addr = (intptr_t) from->si_addr;
-	  break;
-	case SIGPOLL:
-	  to->cpt_si_band = from->si_band;
-	  to->cpt_si_fd = from->si_fd;
-	  break;
-	default:
-	  to->cpt_si_pid = from->si_pid;
-	  to->cpt_si_uid = from->si_uid;
-	  to->cpt_si_ptr = (intptr_t) from->si_ptr;
-	  break;
-	}
-    }
-}
-
-static void
-siginfo_from_compat_siginfo (siginfo_t *to, compat_siginfo_t *from)
-{
-  memset (to, 0, sizeof (*to));
-
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
-
-  if (to->si_code == SI_TIMER)
-    {
-      to->si_timerid = from->cpt_si_timerid;
-      to->si_overrun = from->cpt_si_overrun;
-      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
-    }
-  else if (to->si_code == SI_USER)
-    {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
-    }
-  else if (to->si_code < 0)
-    {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
-      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
-    }
-  else
-    {
-      switch (to->si_signo)
-	{
-	case SIGCHLD:
-	  to->si_pid = from->cpt_si_pid;
-	  to->si_uid = from->cpt_si_uid;
-	  to->si_status = from->cpt_si_status;
-	  to->si_utime = from->cpt_si_utime;
-	  to->si_stime = from->cpt_si_stime;
-	  break;
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	  to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
-	  break;
-	case SIGPOLL:
-	  to->si_band = from->cpt_si_band;
-	  to->si_fd = from->cpt_si_fd;
-	  break;
-	default:
-	  to->si_pid = from->cpt_si_pid;
-	  to->si_uid = from->cpt_si_uid;
-	  to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
-	  break;
-	}
-    }
-}
-
-static void
-compat_x32_siginfo_from_siginfo (compat_x32_siginfo_t *to,
-				 siginfo_t *from)
-{
-  memset (to, 0, sizeof (*to));
-
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
-
-  if (to->si_code == SI_TIMER)
-    {
-      to->cpt_si_timerid = from->si_timerid;
-      to->cpt_si_overrun = from->si_overrun;
-      to->cpt_si_ptr = (intptr_t) from->si_ptr;
-    }
-  else if (to->si_code == SI_USER)
-    {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
-    }
-  else if (to->si_code < 0)
-    {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
-      to->cpt_si_ptr = (intptr_t) from->si_ptr;
-    }
-  else
-    {
-      switch (to->si_signo)
-	{
-	case SIGCHLD:
-	  to->cpt_si_pid = from->si_pid;
-	  to->cpt_si_uid = from->si_uid;
-	  to->cpt_si_status = from->si_status;
-	  to->cpt_si_utime = from->si_utime;
-	  to->cpt_si_stime = from->si_stime;
-	  break;
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	  to->cpt_si_addr = (intptr_t) from->si_addr;
-	  break;
-	case SIGPOLL:
-	  to->cpt_si_band = from->si_band;
-	  to->cpt_si_fd = from->si_fd;
-	  break;
-	default:
-	  to->cpt_si_pid = from->si_pid;
-	  to->cpt_si_uid = from->si_uid;
-	  to->cpt_si_ptr = (intptr_t) from->si_ptr;
-	  break;
-	}
-    }
-}
-
-static void
-siginfo_from_compat_x32_siginfo (siginfo_t *to,
-				 compat_x32_siginfo_t *from)
-{
-  memset (to, 0, sizeof (*to));
-
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
-
-  if (to->si_code == SI_TIMER)
-    {
-      to->si_timerid = from->cpt_si_timerid;
-      to->si_overrun = from->cpt_si_overrun;
-      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
-    }
-  else if (to->si_code == SI_USER)
-    {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
-    }
-  else if (to->si_code < 0)
-    {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
-      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
-    }
-  else
-    {
-      switch (to->si_signo)
-	{
-	case SIGCHLD:
-	  to->si_pid = from->cpt_si_pid;
-	  to->si_uid = from->cpt_si_uid;
-	  to->si_status = from->cpt_si_status;
-	  to->si_utime = from->cpt_si_utime;
-	  to->si_stime = from->cpt_si_stime;
-	  break;
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	  to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
-	  break;
-	case SIGPOLL:
-	  to->si_band = from->cpt_si_band;
-	  to->si_fd = from->cpt_si_fd;
-	  break;
-	default:
-	  to->si_pid = from->cpt_si_pid;
-	  to->si_uid = from->cpt_si_uid;
-	  to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
-	  break;
-	}
-    }
-}
-
-#endif /* __x86_64__ */
-
 /* Convert a native/host 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
@@ -1079,30 +690,12 @@ x86_siginfo_fixup (siginfo_t *native, void *inf, int direction)
 
   /* Is the inferior 32-bit?  If so, then fixup the siginfo object.  */
   if (!is_64bit_tdesc ())
-    {
-      gdb_assert (sizeof (siginfo_t) == sizeof (compat_siginfo_t));
-
-      if (direction == 0)
-	compat_siginfo_from_siginfo ((struct compat_siginfo *) inf, native);
-      else
-	siginfo_from_compat_siginfo (native, (struct compat_siginfo *) inf);
-
-      return 1;
-    }
+      return amd64_linux_siginfo_fixup_common (native, inf, direction,
+					       FIXUP_32);
   /* No fixup for native x32 GDB.  */
   else if (!is_elf64 && sizeof (void *) == 8)
-    {
-      gdb_assert (sizeof (siginfo_t) == sizeof (compat_x32_siginfo_t));
-
-      if (direction == 0)
-	compat_x32_siginfo_from_siginfo ((struct compat_x32_siginfo *) inf,
-					 native);
-      else
-	siginfo_from_compat_x32_siginfo (native,
-					 (struct compat_x32_siginfo *) inf);
-
-      return 1;
-    }
+    return amd64_linux_siginfo_fixup_common (native, inf, direction,
+					     FIXUP_X32);
 #endif
 
   return 0;
diff --git a/gdb/nat/amd64-linux-siginfo.c b/gdb/nat/amd64-linux-siginfo.c
new file mode 100644
index 00000000000..36b55050ccd
--- /dev/null
+++ b/gdb/nat/amd64-linux-siginfo.c
@@ -0,0 +1,462 @@
+/* Low-level siginfo manipulation for amd64.
+
+   Copyright (C) 2002-2016 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 "common-defs.h"
+#include "amd64-linux-siginfo.h"
+
+/* 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;
+};
+
+typedef union compat_sigval
+{
+  compat_int_t sival_int;
+  compat_uptr_t sival_ptr;
+} compat_sigval_t;
+
+typedef struct compat_siginfo
+{
+  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;
+    } _sigfault;
+
+    /* SIGPOLL */
+    struct
+    {
+      int _band;
+      int _fd;
+    } _sigpoll;
+  } _sifields;
+} compat_siginfo_t;
+
+/* For x32, clock_t in _sigchld is 64bit aligned at 4 bytes.  */
+typedef long __attribute__ ((__aligned__ (4))) compat_x32_clock_t;
+
+typedef struct compat_x32_siginfo
+{
+  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;
+    } _sigfault;
+
+    /* SIGPOLL */
+    struct
+    {
+      int _band;
+      int _fd;
+    } _sigpoll;
+  } _sifields;
+} compat_x32_siginfo_t __attribute__ ((__aligned__ (8)));
+
+/* 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_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
+
+/*  Convert the system provided siginfo into compatible siginfo.  */
+
+static void
+compat_siginfo_from_siginfo (compat_siginfo_t *to, siginfo_t *from)
+{
+  memset (to, 0, sizeof (*to));
+
+  to->si_signo = from->si_signo;
+  to->si_errno = from->si_errno;
+  to->si_code = from->si_code;
+
+  if (to->si_code == SI_TIMER)
+    {
+      to->cpt_si_timerid = from->si_timerid;
+      to->cpt_si_overrun = from->si_overrun;
+      to->cpt_si_ptr = (intptr_t) from->si_ptr;
+    }
+  else if (to->si_code == SI_USER)
+    {
+      to->cpt_si_pid = from->si_pid;
+      to->cpt_si_uid = from->si_uid;
+    }
+  else if (to->si_code < 0)
+    {
+      to->cpt_si_pid = from->si_pid;
+      to->cpt_si_uid = from->si_uid;
+      to->cpt_si_ptr = (intptr_t) from->si_ptr;
+    }
+  else
+    {
+      switch (to->si_signo)
+	{
+	case SIGCHLD:
+	  to->cpt_si_pid = from->si_pid;
+	  to->cpt_si_uid = from->si_uid;
+	  to->cpt_si_status = from->si_status;
+	  to->cpt_si_utime = from->si_utime;
+	  to->cpt_si_stime = from->si_stime;
+	  break;
+	case SIGILL:
+	case SIGFPE:
+	case SIGSEGV:
+	case SIGBUS:
+	  to->cpt_si_addr = (intptr_t) from->si_addr;
+	  break;
+	case SIGPOLL:
+	  to->cpt_si_band = from->si_band;
+	  to->cpt_si_fd = from->si_fd;
+	  break;
+	default:
+	  to->cpt_si_pid = from->si_pid;
+	  to->cpt_si_uid = from->si_uid;
+	  to->cpt_si_ptr = (intptr_t) from->si_ptr;
+	  break;
+	}
+    }
+}
+
+/* Convert the compatible siginfo into system siginfo.  */
+
+static void
+siginfo_from_compat_siginfo (siginfo_t *to, compat_siginfo_t *from)
+{
+  memset (to, 0, sizeof (*to));
+
+  to->si_signo = from->si_signo;
+  to->si_errno = from->si_errno;
+  to->si_code = from->si_code;
+
+  if (to->si_code == SI_TIMER)
+    {
+      to->si_timerid = from->cpt_si_timerid;
+      to->si_overrun = from->cpt_si_overrun;
+      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
+    }
+  else if (to->si_code == SI_USER)
+    {
+      to->si_pid = from->cpt_si_pid;
+      to->si_uid = from->cpt_si_uid;
+    }
+  if (to->si_code < 0)
+    {
+      to->si_pid = from->cpt_si_pid;
+      to->si_uid = from->cpt_si_uid;
+      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
+    }
+  else
+    {
+      switch (to->si_signo)
+	{
+	case SIGCHLD:
+	  to->si_pid = from->cpt_si_pid;
+	  to->si_uid = from->cpt_si_uid;
+	  to->si_status = from->cpt_si_status;
+	  to->si_utime = from->cpt_si_utime;
+	  to->si_stime = from->cpt_si_stime;
+	  break;
+	case SIGILL:
+	case SIGFPE:
+	case SIGSEGV:
+	case SIGBUS:
+	  to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
+	  break;
+	case SIGPOLL:
+	  to->si_band = from->cpt_si_band;
+	  to->si_fd = from->cpt_si_fd;
+	  break;
+	default:
+	  to->si_pid = from->cpt_si_pid;
+	  to->si_uid = from->cpt_si_uid;
+	  to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
+	  break;
+	}
+    }
+}
+
+/*  Convert the system provided siginfo into compatible x32 siginfo.  */
+
+static void
+compat_x32_siginfo_from_siginfo (compat_x32_siginfo_t *to,
+				 siginfo_t *from)
+{
+  memset (to, 0, sizeof (*to));
+
+  to->si_signo = from->si_signo;
+  to->si_errno = from->si_errno;
+  to->si_code = from->si_code;
+
+  if (to->si_code == SI_TIMER)
+    {
+      to->cpt_si_timerid = from->si_timerid;
+      to->cpt_si_overrun = from->si_overrun;
+      to->cpt_si_ptr = (intptr_t) from->si_ptr;
+    }
+  else if (to->si_code == SI_USER)
+    {
+      to->cpt_si_pid = from->si_pid;
+      to->cpt_si_uid = from->si_uid;
+    }
+  else if (to->si_code < 0)
+    {
+      to->cpt_si_pid = from->si_pid;
+      to->cpt_si_uid = from->si_uid;
+      to->cpt_si_ptr = (intptr_t) from->si_ptr;
+    }
+  else
+    {
+      switch (to->si_signo)
+	{
+	case SIGCHLD:
+	  to->cpt_si_pid = from->si_pid;
+	  to->cpt_si_uid = from->si_uid;
+	  to->cpt_si_status = from->si_status;
+	  memcpy (&to->cpt_si_utime, &from->si_utime,
+		  sizeof (to->cpt_si_utime));
+	  memcpy (&to->cpt_si_stime, &from->si_stime,
+		  sizeof (to->cpt_si_stime));
+	  break;
+	case SIGILL:
+	case SIGFPE:
+	case SIGSEGV:
+	case SIGBUS:
+	  to->cpt_si_addr = (intptr_t) from->si_addr;
+	  break;
+	case SIGPOLL:
+	  to->cpt_si_band = from->si_band;
+	  to->cpt_si_fd = from->si_fd;
+	  break;
+	default:
+	  to->cpt_si_pid = from->si_pid;
+	  to->cpt_si_uid = from->si_uid;
+	  to->cpt_si_ptr = (intptr_t) from->si_ptr;
+	  break;
+	}
+    }
+}
+
+/* Convert the compatible x32 siginfo into system siginfo.  */
+static void
+siginfo_from_compat_x32_siginfo (siginfo_t *to,
+				 compat_x32_siginfo_t *from)
+{
+  memset (to, 0, sizeof (*to));
+
+  to->si_signo = from->si_signo;
+  to->si_errno = from->si_errno;
+  to->si_code = from->si_code;
+
+  if (to->si_code == SI_TIMER)
+    {
+      to->si_timerid = from->cpt_si_timerid;
+      to->si_overrun = from->cpt_si_overrun;
+      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
+    }
+  else if (to->si_code == SI_USER)
+    {
+      to->si_pid = from->cpt_si_pid;
+      to->si_uid = from->cpt_si_uid;
+    }
+  if (to->si_code < 0)
+    {
+      to->si_pid = from->cpt_si_pid;
+      to->si_uid = from->cpt_si_uid;
+      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
+    }
+  else
+    {
+      switch (to->si_signo)
+	{
+	case SIGCHLD:
+	  to->si_pid = from->cpt_si_pid;
+	  to->si_uid = from->cpt_si_uid;
+	  to->si_status = from->cpt_si_status;
+	  memcpy (&to->si_utime, &from->cpt_si_utime,
+		  sizeof (to->si_utime));
+	  memcpy (&to->si_stime, &from->cpt_si_stime,
+		  sizeof (to->si_stime));
+	  break;
+	case SIGILL:
+	case SIGFPE:
+	case SIGSEGV:
+	case SIGBUS:
+	  to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
+	  break;
+	case SIGPOLL:
+	  to->si_band = from->cpt_si_band;
+	  to->si_fd = from->cpt_si_fd;
+	  break;
+	default:
+	  to->si_pid = from->cpt_si_pid;
+	  to->si_uid = from->cpt_si_uid;
+	  to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
+	  break;
+	}
+    }
+}
+
+/* Convert a native/host 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 NATIVE.  If DIRECTION is 0, then copy from NATIVE to INF.  */
+
+int
+amd64_linux_siginfo_fixup_common (siginfo_t *native, gdb_byte *inf,
+				  int direction,
+				  enum amd64_siginfo_fixup_mode mode)
+{
+  if (mode == FIXUP_32)
+    {
+      gdb_assert (sizeof (siginfo_t) == sizeof (compat_siginfo_t));
+
+      if (direction == 0)
+	compat_siginfo_from_siginfo ((struct compat_siginfo *) inf, native);
+      else
+	siginfo_from_compat_siginfo (native, (struct compat_siginfo *) inf);
+
+      return 1;
+    }
+  else if (mode == FIXUP_X32)
+    {
+      gdb_assert (sizeof (siginfo_t) == sizeof (compat_x32_siginfo_t));
+
+      if (direction == 0)
+	compat_x32_siginfo_from_siginfo ((struct compat_x32_siginfo *) inf,
+					 native);
+      else
+	siginfo_from_compat_x32_siginfo (native,
+					 (struct compat_x32_siginfo *) inf);
+
+      return 1;
+    }
+  return 0;
+}
diff --git a/gdb/nat/amd64-linux-siginfo.h b/gdb/nat/amd64-linux-siginfo.h
new file mode 100644
index 00000000000..a3969663c8b
--- /dev/null
+++ b/gdb/nat/amd64-linux-siginfo.h
@@ -0,0 +1,44 @@
+/* Low-level siginfo manipulation for amd64.
+
+   Copyright (C) 2016 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/>.  */
+
+#ifndef AMD64_LINUX_SIGINFO_H
+#define AMD64_LINUX_SIGINFO_H 1
+
+
+/* When GDB is built as a 64-bit application on Linux, the
+   PTRACE_GETSIGINFO data is always presented in 64-bit layout.  Since
+   debugging a 32-bit inferior with a 64-bit GDB should look the same
+   as debugging it with a 32-bit GDB, we do the 32-bit <-> 64-bit
+   conversion in-place ourselves.  */
+
+/* Kind of siginfo fixup to be performed.  */
+
+enum amd64_siginfo_fixup_mode
+{
+  FIXUP_32 = 1,   /* Fixup for 32bit.  */
+  FIXUP_X32 = 2   /* Fixup for x32.  */
+};
+
+/* Common code for performing the fixup of the siginfo.  */
+
+int amd64_linux_siginfo_fixup_common (siginfo_t *native, gdb_byte *inf,
+				      int direction,
+				      enum amd64_siginfo_fixup_mode mode);
+
+#endif