Move shared native target specific code to gdb/nat

https://sourceware.org/gdb/wiki/Common describes the following
directory structure:

 gdb/nat/
   Native target backend files. Code that interfaces with the
   host debug API. E.g., ptrace code, Windows debug API code,
   procfs code should go here.

 gdb/target/
   Host-independent, target vector specific code (target_ops).

 gdb/common/
   All other shared code.

This commit moves all native target backend files currently in
gdb/common to gdb/nat.

gdb/
2014-06-20  Gary Benson  <gbenson@redhat.com>

	* common/gdb_thread_db.h: Moved to nat.  All includes updated.
	* common/glibc_thread_db.h: Likewise.
	* common/i386-cpuid.h: Likewise.
	* common/i386-gcc-cpuid.h: Likewise.
	* common/linux-btrace.h: Likewise.
	* common/linux-osdata.h: Likewise.
	* common/linux-procfs.h: Likewise.
	* common/linux-ptrace.h: Likewise.
	* common/mips-linux-watch.h: Likewise.
	* common/linux-btrace.c: Moved to nat.
	* common/linux-osdata.c: Likewise.
	* common/linux-procfs.c: Likewise.
	* common/linux-ptrace.c: Likewise.
	* common/mips-linux-watch.c: Likewise.
	* nat/gdb_thread_db.h: Moved from common.
	* nat/glibc_thread_db.h: Likewise.
	* nat/i386-cpuid.h: Likewise.
	* nat/i386-gcc-cpuid.h: Likewise.
	* nat/linux-btrace.c: Likewise.
	* nat/linux-btrace.h: Likewise.
	* nat/linux-osdata.c: Likewise.
	* nat/linux-osdata.h: Likewise.
	* nat/linux-procfs.c: Likewise.
	* nat/linux-procfs.h: Likewise.
	* nat/linux-ptrace.c: Likewise.
	* nat/linux-ptrace.h: Likewise.
	* nat/mips-linux-watch.c: Likewise.
	* nat/mips-linux-watch.h: Likewise.
	* Makefile.in (HFILES_NO_SRCDIR): Reflect new locations.
	(object file files): Reordered.
	* gdb/copyright.py (EXCLUDE_LIST): Reflect new location
	of glibc_thread_db.h.

gdb/gdbserver/
2014-06-20  Gary Benson  <gbenson@redhat.com>

	* Makefile.in (SFILES): Update locations for files moved
	from common to nat.
	(object file files): Reordered.

gdb/testsuite/
2014-06-20  Gary Benson  <gbenson@redhat.com>

	* gdb.arch/i386-avx.exp: Fix include file location.
	* gdb.arch/i386-sse.exp: Likewise.

16 files changed, 4480 insertions, 3 deletions

diff --git a/gdb/nat/gdb_thread_db.h b/gdb/nat/gdb_thread_db.h
new file mode 100644
index 0000000..a1d9473
--- /dev/null
+++ b/gdb/nat/gdb_thread_db.h
@@ -0,0 +1,16 @@
+#ifdef HAVE_THREAD_DB_H
+#include <thread_db.h>
+#else
+#include "glibc_thread_db.h"
+#endif
+
+#ifndef LIBTHREAD_DB_SO
+#define LIBTHREAD_DB_SO "libthread_db.so.1"
+#endif
+
+#ifndef LIBTHREAD_DB_SEARCH_PATH
+/* $sdir appears before $pdir for some minimal security protection:
+   we trust the system libthread_db.so a bit more than some random
+   libthread_db associated with whatever libpthread the app is using.  */
+#define LIBTHREAD_DB_SEARCH_PATH "$sdir:$pdir"
+#endif
diff --git a/gdb/nat/glibc_thread_db.h b/gdb/nat/glibc_thread_db.h
new file mode 100644
index 0000000..97423a4
--- /dev/null
+++ b/gdb/nat/glibc_thread_db.h
@@ -0,0 +1,458 @@
+/* thread_db.h -- interface to libthread_db.so library for debugging -lpthread
+   Copyright (C) 1999-2013 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 _THREAD_DB_H
+#define _THREAD_DB_H	1
+
+/* This is the debugger interface for the NPTL library.  It is
+   modelled closely after the interface with same names in Solaris
+   with the goal to share the same code in the debugger.  */
+#include <pthread.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/procfs.h>
+
+
+/* Error codes of the library.  */
+typedef enum
+{
+  TD_OK,	  /* No error.  */
+  TD_ERR,	  /* No further specified error.  */
+  TD_NOTHR,	  /* No matching thread found.  */
+  TD_NOSV,	  /* No matching synchronization handle found.  */
+  TD_NOLWP,	  /* No matching light-weighted process found.  */
+  TD_BADPH,	  /* Invalid process handle.  */
+  TD_BADTH,	  /* Invalid thread handle.  */
+  TD_BADSH,	  /* Invalid synchronization handle.  */
+  TD_BADTA,	  /* Invalid thread agent.  */
+  TD_BADKEY,	  /* Invalid key.  */
+  TD_NOMSG,	  /* No event available.  */
+  TD_NOFPREGS,	  /* No floating-point register content available.  */
+  TD_NOLIBTHREAD, /* Application not linked with thread library.  */
+  TD_NOEVENT,	  /* Requested event is not supported.  */
+  TD_NOCAPAB,	  /* Capability not available.  */
+  TD_DBERR,	  /* Internal debug library error.  */
+  TD_NOAPLIC,	  /* Operation is not applicable.  */
+  TD_NOTSD,	  /* No thread-specific data available.  */
+  TD_MALLOC,	  /* Out of memory.  */
+  TD_PARTIALREG,  /* Not entire register set was read or written.  */
+  TD_NOXREGS,	  /* X register set not available for given thread.  */
+  TD_TLSDEFER,	  /* Thread has not yet allocated TLS for given module.  */
+  TD_NOTALLOC = TD_TLSDEFER,
+  TD_VERSION,	  /* Version if libpthread and libthread_db do not match.  */
+  TD_NOTLS	  /* There is no TLS segment in the given module.  */
+} td_err_e;
+
+
+/* Possible thread states.  TD_THR_ANY_STATE is a pseudo-state used to
+   select threads regardless of state in td_ta_thr_iter().  */
+typedef enum
+{
+  TD_THR_ANY_STATE,
+  TD_THR_UNKNOWN,
+  TD_THR_STOPPED,
+  TD_THR_RUN,
+  TD_THR_ACTIVE,
+  TD_THR_ZOMBIE,
+  TD_THR_SLEEP,
+  TD_THR_STOPPED_ASLEEP
+} td_thr_state_e;
+
+/* Thread type: user or system.  TD_THR_ANY_TYPE is a pseudo-type used
+   to select threads regardless of type in td_ta_thr_iter().  */
+typedef enum
+{
+  TD_THR_ANY_TYPE,
+  TD_THR_USER,
+  TD_THR_SYSTEM
+} td_thr_type_e;
+
+
+/* Types of the debugging library.  */
+
+/* Handle for a process.  This type is opaque.  */
+typedef struct td_thragent td_thragent_t;
+
+/* The actual thread handle type.  This is also opaque.  */
+typedef struct td_thrhandle
+{
+  td_thragent_t *th_ta_p;
+  psaddr_t th_unique;
+} td_thrhandle_t;
+
+
+/* Forward declaration of a type defined by and for the dynamic linker.  */
+struct link_map;
+
+
+/* Flags for `td_ta_thr_iter'.  */
+#define TD_THR_ANY_USER_FLAGS	0xffffffff
+#define TD_THR_LOWEST_PRIORITY	-20
+#define TD_SIGNO_MASK		NULL
+
+
+#define TD_EVENTSIZE	2
+#define BT_UISHIFT	5 /* log base 2 of BT_NBIPUI, to extract word index */
+#define BT_NBIPUI	(1 << BT_UISHIFT)       /* n bits per uint */
+#define BT_UIMASK	(BT_NBIPUI - 1)         /* to extract bit index */
+
+/* Bitmask of enabled events. */
+typedef struct td_thr_events
+{
+  uint32_t event_bits[TD_EVENTSIZE];
+} td_thr_events_t;
+
+/* Event set manipulation macros. */
+#define __td_eventmask(n) \
+  (UINT32_C (1) << (((n) - 1) & BT_UIMASK))
+#define __td_eventword(n) \
+  ((UINT32_C ((n) - 1)) >> BT_UISHIFT)
+
+#define td_event_emptyset(setp) \
+  do {									      \
+    int __i;								      \
+    for (__i = TD_EVENTSIZE; __i > 0; --__i)				      \
+      (setp)->event_bits[__i - 1] = 0;					      \
+  } while (0)
+
+#define td_event_fillset(setp) \
+  do {									      \
+    int __i;								      \
+    for (__i = TD_EVENTSIZE; __i > 0; --__i)				      \
+      (setp)->event_bits[__i - 1] = UINT32_C (0xffffffff);		      \
+  } while (0)
+
+#define td_event_addset(setp, n) \
+  (((setp)->event_bits[__td_eventword (n)]) |= __td_eventmask (n))
+#define td_event_delset(setp, n) \
+  (((setp)->event_bits[__td_eventword (n)]) &= ~__td_eventmask (n))
+#define td_eventismember(setp, n) \
+  (__td_eventmask (n) & ((setp)->event_bits[__td_eventword (n)]))
+#if TD_EVENTSIZE == 2
+# define td_eventisempty(setp) \
+  (!((setp)->event_bits[0]) && !((setp)->event_bits[1]))
+#else
+# error "td_eventisempty must be changed to match TD_EVENTSIZE"
+#endif
+
+/* Events reportable by the thread implementation.  */
+typedef enum
+{
+  TD_ALL_EVENTS,		 /* Pseudo-event number.  */
+  TD_EVENT_NONE = TD_ALL_EVENTS, /* Depends on context.  */
+  TD_READY,			 /* Is executable now. */
+  TD_SLEEP,			 /* Blocked in a synchronization obj.  */
+  TD_SWITCHTO,			 /* Now assigned to a process.  */
+  TD_SWITCHFROM,		 /* Not anymore assigned to a process.  */
+  TD_LOCK_TRY,			 /* Trying to get an unavailable lock.  */
+  TD_CATCHSIG,			 /* Signal posted to the thread.  */
+  TD_IDLE,			 /* Process getting idle.  */
+  TD_CREATE,			 /* New thread created.  */
+  TD_DEATH,			 /* Thread terminated.  */
+  TD_PREEMPT,			 /* Preempted.  */
+  TD_PRI_INHERIT,		 /* Inherited elevated priority.  */
+  TD_REAP,			 /* Reaped.  */
+  TD_CONCURRENCY,		 /* Number of processes changing.  */
+  TD_TIMEOUT,			 /* Conditional variable wait timed out.  */
+  TD_MIN_EVENT_NUM = TD_READY,
+  TD_MAX_EVENT_NUM = TD_TIMEOUT,
+  TD_EVENTS_ENABLE = 31		/* Event reporting enabled.  */
+} td_event_e;
+
+/* Values representing the different ways events are reported.  */
+typedef enum
+{
+  NOTIFY_BPT,			/* User must insert breakpoint at u.bptaddr. */
+  NOTIFY_AUTOBPT,		/* Breakpoint at u.bptaddr is automatically
+				   inserted.  */
+  NOTIFY_SYSCALL		/* System call u.syscallno will be invoked.  */
+} td_notify_e;
+
+/* Description how event type is reported.  */
+typedef struct td_notify
+{
+  td_notify_e type;		/* Way the event is reported.  */
+  union
+  {
+    psaddr_t bptaddr;		/* Address of breakpoint.  */
+    int syscallno;		/* Number of system call used.  */
+  } u;
+} td_notify_t;
+
+/* Structure used to report event.  */
+typedef struct td_event_msg
+{
+  td_event_e event;		/* Event type being reported.  */
+  const td_thrhandle_t *th_p;	/* Thread reporting the event.  */
+  union
+  {
+# if 0
+    td_synchandle_t *sh;	/* Handle of synchronization object.  */
+#endif
+    uintptr_t data;		/* Event specific data.  */
+  } msg;
+} td_event_msg_t;
+
+/* Structure containing event data available in each thread structure.  */
+typedef struct
+{
+  td_thr_events_t eventmask;	/* Mask of enabled events.  */
+  td_event_e eventnum;		/* Number of last event.  */
+  void *eventdata;		/* Data associated with event.  */
+} td_eventbuf_t;
+
+
+/* Gathered statistics about the process.  */
+typedef struct td_ta_stats
+{
+  int nthreads;       		/* Total number of threads in use.  */
+  int r_concurrency;		/* Concurrency level requested by user.  */
+  int nrunnable_num;		/* Average runnable threads, numerator.  */
+  int nrunnable_den;		/* Average runnable threads, denominator.  */
+  int a_concurrency_num;	/* Achieved concurrency level, numerator.  */
+  int a_concurrency_den;	/* Achieved concurrency level, denominator.  */
+  int nlwps_num;		/* Average number of processes in use,
+				   numerator.  */
+  int nlwps_den;		/* Average number of processes in use,
+				   denominator.  */
+  int nidle_num;		/* Average number of idling processes,
+				   numerator.  */
+  int nidle_den;		/* Average number of idling processes,
+				   denominator.  */
+} td_ta_stats_t;
+
+
+/* Since Sun's library is based on Solaris threads we have to define a few
+   types to map them to POSIX threads.  */
+typedef pthread_t thread_t;
+typedef pthread_key_t thread_key_t;
+
+
+/* Callback for iteration over threads.  */
+typedef int td_thr_iter_f (const td_thrhandle_t *, void *);
+
+/* Callback for iteration over thread local data.  */
+typedef int td_key_iter_f (thread_key_t, void (*) (void *), void *);
+
+
+
+/* Forward declaration.  This has to be defined by the user.  */
+struct ps_prochandle;
+
+
+/* Information about the thread.  */
+typedef struct td_thrinfo
+{
+  td_thragent_t *ti_ta_p;		/* Process handle.  */
+  unsigned int ti_user_flags;		/* Unused.  */
+  thread_t ti_tid;			/* Thread ID returned by
+					   pthread_create().  */
+  char *ti_tls;				/* Pointer to thread-local data.  */
+  psaddr_t ti_startfunc;		/* Start function passed to
+					   pthread_create().  */
+  psaddr_t ti_stkbase;			/* Base of thread's stack.  */
+  long int ti_stksize;			/* Size of thread's stack.  */
+  psaddr_t ti_ro_area;			/* Unused.  */
+  int ti_ro_size;			/* Unused.  */
+  td_thr_state_e ti_state;		/* Thread state.  */
+  unsigned char ti_db_suspended;	/* Nonzero if suspended by debugger. */
+  td_thr_type_e ti_type;		/* Type of the thread (system vs
+					   user thread).  */
+  intptr_t ti_pc;			/* Unused.  */
+  intptr_t ti_sp;			/* Unused.  */
+  short int ti_flags;			/* Unused.  */
+  int ti_pri;				/* Thread priority.  */
+  lwpid_t ti_lid;			/* Kernel PID for this thread.  */
+  sigset_t ti_sigmask;			/* Signal mask.  */
+  unsigned char ti_traceme;		/* Nonzero if event reporting
+					   enabled.  */
+  unsigned char ti_preemptflag;		/* Unused.  */
+  unsigned char ti_pirecflag;		/* Unused.  */
+  sigset_t ti_pending;			/* Set of pending signals.  */
+  td_thr_events_t ti_events;		/* Set of enabled events.  */
+} td_thrinfo_t;
+
+
+
+/* Prototypes for exported library functions.  */
+
+/* Initialize the thread debug support library.  */
+extern td_err_e td_init (void);
+
+/* Historical relict.  Should not be used anymore.  */
+extern td_err_e td_log (void);
+
+/* Return list of symbols the library can request.  */
+extern const char **td_symbol_list (void);
+
+/* Generate new thread debug library handle for process PS.  */
+extern td_err_e td_ta_new (struct ps_prochandle *__ps, td_thragent_t **__ta);
+
+/* Free resources allocated for TA.  */
+extern td_err_e td_ta_delete (td_thragent_t *__ta);
+
+/* Get number of currently running threads in process associated with TA.  */
+extern td_err_e td_ta_get_nthreads (const td_thragent_t *__ta, int *__np);
+
+/* Return process handle passed in `td_ta_new' for process associated with
+   TA.  */
+extern td_err_e td_ta_get_ph (const td_thragent_t *__ta,
+			      struct ps_prochandle **__ph);
+
+/* Map thread library handle PT to thread debug library handle for process
+   associated with TA and store result in *TH.  */
+extern td_err_e td_ta_map_id2thr (const td_thragent_t *__ta, pthread_t __pt,
+				  td_thrhandle_t *__th);
+
+/* Map process ID LWPID to thread debug library handle for process
+   associated with TA and store result in *TH.  */
+extern td_err_e td_ta_map_lwp2thr (const td_thragent_t *__ta, lwpid_t __lwpid,
+				   td_thrhandle_t *__th);
+
+
+/* Call for each thread in a process associated with TA the callback function
+   CALLBACK.  */
+extern td_err_e td_ta_thr_iter (const td_thragent_t *__ta,
+				td_thr_iter_f *__callback, void *__cbdata_p,
+				td_thr_state_e __state, int __ti_pri,
+				sigset_t *__ti_sigmask_p,
+				unsigned int __ti_user_flags);
+
+/* Call for each defined thread local data entry the callback function KI.  */
+extern td_err_e td_ta_tsd_iter (const td_thragent_t *__ta, td_key_iter_f *__ki,
+				void *__p);
+
+
+/* Get event address for EVENT.  */
+extern td_err_e td_ta_event_addr (const td_thragent_t *__ta,
+				  td_event_e __event, td_notify_t *__ptr);
+
+/* Enable EVENT in global mask.  */
+extern td_err_e td_ta_set_event (const td_thragent_t *__ta,
+				 td_thr_events_t *__event);
+
+/* Disable EVENT in global mask.  */
+extern td_err_e td_ta_clear_event (const td_thragent_t *__ta,
+				   td_thr_events_t *__event);
+
+/* Return information about last event.  */
+extern td_err_e td_ta_event_getmsg (const td_thragent_t *__ta,
+				    td_event_msg_t *__msg);
+
+
+/* Set suggested concurrency level for process associated with TA.  */
+extern td_err_e td_ta_setconcurrency (const td_thragent_t *__ta, int __level);
+
+
+/* Enable collecting statistics for process associated with TA.  */
+extern td_err_e td_ta_enable_stats (const td_thragent_t *__ta, int __enable);
+
+/* Reset statistics.  */
+extern td_err_e td_ta_reset_stats (const td_thragent_t *__ta);
+
+/* Retrieve statistics from process associated with TA.  */
+extern td_err_e td_ta_get_stats (const td_thragent_t *__ta,
+				 td_ta_stats_t *__statsp);
+
+
+/* Validate that TH is a thread handle.  */
+extern td_err_e td_thr_validate (const td_thrhandle_t *__th);
+
+/* Return information about thread TH.  */
+extern td_err_e td_thr_get_info (const td_thrhandle_t *__th,
+				 td_thrinfo_t *__infop);
+
+/* Retrieve floating-point register contents of process running thread TH.  */
+extern td_err_e td_thr_getfpregs (const td_thrhandle_t *__th,
+				  prfpregset_t *__regset);
+
+/* Retrieve general register contents of process running thread TH.  */
+extern td_err_e td_thr_getgregs (const td_thrhandle_t *__th,
+				 prgregset_t __gregs);
+
+/* Retrieve extended register contents of process running thread TH.  */
+extern td_err_e td_thr_getxregs (const td_thrhandle_t *__th, void *__xregs);
+
+/* Get size of extended register set of process running thread TH.  */
+extern td_err_e td_thr_getxregsize (const td_thrhandle_t *__th, int *__sizep);
+
+/* Set floating-point register contents of process running thread TH.  */
+extern td_err_e td_thr_setfpregs (const td_thrhandle_t *__th,
+				  const prfpregset_t *__fpregs);
+
+/* Set general register contents of process running thread TH.  */
+extern td_err_e td_thr_setgregs (const td_thrhandle_t *__th,
+				 prgregset_t __gregs);
+
+/* Set extended register contents of process running thread TH.  */
+extern td_err_e td_thr_setxregs (const td_thrhandle_t *__th,
+				 const void *__addr);
+
+
+/* Get address of the given module's TLS storage area for the given thread.  */
+extern td_err_e td_thr_tlsbase (const td_thrhandle_t *__th,
+				unsigned long int __modid,
+				psaddr_t *__base);
+
+/* Get address of thread local variable.  */
+extern td_err_e td_thr_tls_get_addr (const td_thrhandle_t *__th,
+				     psaddr_t __map_address, size_t __offset,
+				     psaddr_t *__address);
+
+
+/* Enable reporting for EVENT for thread TH.  */
+extern td_err_e td_thr_event_enable (const td_thrhandle_t *__th, int __event);
+
+/* Enable EVENT for thread TH.  */
+extern td_err_e td_thr_set_event (const td_thrhandle_t *__th,
+				  td_thr_events_t *__event);
+
+/* Disable EVENT for thread TH.  */
+extern td_err_e td_thr_clear_event (const td_thrhandle_t *__th,
+				    td_thr_events_t *__event);
+
+/* Get event message for thread TH.  */
+extern td_err_e td_thr_event_getmsg (const td_thrhandle_t *__th,
+				     td_event_msg_t *__msg);
+
+
+/* Set priority of thread TH.  */
+extern td_err_e td_thr_setprio (const td_thrhandle_t *__th, int __prio);
+
+
+/* Set pending signals for thread TH.  */
+extern td_err_e td_thr_setsigpending (const td_thrhandle_t *__th,
+				      unsigned char __n, const sigset_t *__ss);
+
+/* Set signal mask for thread TH.  */
+extern td_err_e td_thr_sigsetmask (const td_thrhandle_t *__th,
+				   const sigset_t *__ss);
+
+
+/* Return thread local data associated with key TK in thread TH.  */
+extern td_err_e td_thr_tsd (const td_thrhandle_t *__th,
+			    const thread_key_t __tk, void **__data);
+
+
+/* Suspend execution of thread TH.  */
+extern td_err_e td_thr_dbsuspend (const td_thrhandle_t *__th);
+
+/* Resume execution of thread TH.  */
+extern td_err_e td_thr_dbresume (const td_thrhandle_t *__th);
+
+#endif	/* thread_db.h */
diff --git a/gdb/nat/i386-cpuid.h b/gdb/nat/i386-cpuid.h
new file mode 100644
index 0000000..9aea054
--- /dev/null
+++ b/gdb/nat/i386-cpuid.h
@@ -0,0 +1,63 @@
+/* C API for x86 cpuid insn.
+   Copyright (C) 2007-2014 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This file 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, 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 I386_CPUID_COMMON_H
+#define I386_CPUID_COMMON_H
+
+/* Always include the header for the cpu bit defines.  */
+#include "i386-gcc-cpuid.h"
+
+#if defined(__i386__) || defined(__x86_64__)
+
+/* Return cpuid data for requested cpuid level, as found in returned
+   eax, ebx, ecx and edx registers.  The function checks if cpuid is
+   supported and returns 1 for valid cpuid information or 0 for
+   unsupported cpuid level.  Pointers may be non-null.  */
+
+static __inline int
+i386_cpuid (unsigned int __level,
+	    unsigned int *__eax, unsigned int *__ebx,
+	    unsigned int *__ecx, unsigned int *__edx)
+{
+  unsigned int __scratch;
+
+  if (!__eax)
+    __eax = &__scratch;
+  if (!__ebx)
+    __ebx = &__scratch;
+  if (!__ecx)
+    __ecx = &__scratch;
+  if (!__edx)
+    __edx = &__scratch;
+
+  return __get_cpuid (__level, __eax, __ebx, __ecx, __edx);
+}
+
+#else
+
+static __inline int
+i386_cpuid (unsigned int __level,
+	    unsigned int *__eax, unsigned int *__ebx,
+	    unsigned int *__ecx, unsigned int *__edx)
+{
+  return 0;
+}
+
+#endif /* i386 && x86_64 */
+
+#endif /* I386_CPUID_COMMON_H */
diff --git a/gdb/nat/i386-dregs.c b/gdb/nat/i386-dregs.c
index e7d1620..214616c 100644
--- a/gdb/nat/i386-dregs.c
+++ b/gdb/nat/i386-dregs.c
@@ -23,7 +23,7 @@
 #include "defs.h"
 #include "inferior.h"
 #endif
-#include "nat/i386-dregs.h"
+#include "i386-dregs.h"
 
 /* Support for hardware watchpoints and breakpoints using the i386
    debug registers.
diff --git a/gdb/nat/i386-gcc-cpuid.h b/gdb/nat/i386-gcc-cpuid.h
new file mode 100644
index 0000000..34ab197
--- /dev/null
+++ b/gdb/nat/i386-gcc-cpuid.h
@@ -0,0 +1,278 @@
+/*
+ * Helper cpuid.h file copied from gcc-4.8.0.  Code in gdb should not
+ * include this directly, but pull in i386-cpuid.h and use that func.
+ */
+/*
+ * Copyright (C) 2007-2014 Free Software Foundation, Inc.
+ *
+ * This file 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, or (at your option) any
+ * later version.
+ * 
+ * This file 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.
+ * 
+ * Under Section 7 of GPL version 3, you are granted additional
+ * permissions described in the GCC Runtime Library Exception, version
+ * 3.1, as published by the Free Software Foundation.
+ * 
+ * You should have received a copy of the GNU General Public License and
+ * a copy of the GCC Runtime Library Exception along with this program;
+ * see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+/* %ecx */
+#define bit_SSE3	(1 << 0)
+#define bit_PCLMUL	(1 << 1)
+#define bit_LZCNT	(1 << 5)
+#define bit_SSSE3	(1 << 9)
+#define bit_FMA		(1 << 12)
+#define bit_CMPXCHG16B	(1 << 13)
+#define bit_SSE4_1	(1 << 19)
+#define bit_SSE4_2	(1 << 20)
+#define bit_MOVBE	(1 << 22)
+#define bit_POPCNT	(1 << 23)
+#define bit_AES		(1 << 25)
+#define bit_XSAVE	(1 << 26)
+#define bit_OSXSAVE	(1 << 27)
+#define bit_AVX		(1 << 28)
+#define bit_F16C	(1 << 29)
+#define bit_RDRND	(1 << 30)
+
+/* %edx */
+#define bit_CMPXCHG8B	(1 << 8)
+#define bit_CMOV	(1 << 15)
+#define bit_MMX		(1 << 23)
+#define bit_FXSAVE	(1 << 24)
+#define bit_SSE		(1 << 25)
+#define bit_SSE2	(1 << 26)
+
+/* Extended Features */
+/* %ecx */
+#define bit_LAHF_LM	(1 << 0)
+#define bit_ABM		(1 << 5)
+#define bit_SSE4a	(1 << 6)
+#define bit_PRFCHW	(1 << 8)
+#define bit_XOP         (1 << 11)
+#define bit_LWP 	(1 << 15)
+#define bit_FMA4        (1 << 16)
+#define bit_TBM         (1 << 21)
+
+/* %edx */
+#define bit_MMXEXT	(1 << 22)
+#define bit_LM		(1 << 29)
+#define bit_3DNOWP	(1 << 30)
+#define bit_3DNOW	(1 << 31)
+
+/* Extended Features (%eax == 7) */
+#define bit_FSGSBASE	(1 << 0)
+#define bit_BMI	(1 << 3)
+#define bit_HLE	(1 << 4)
+#define bit_AVX2	(1 << 5)
+#define bit_BMI2	(1 << 8)
+#define bit_RTM	(1 << 11)
+#define bit_AVX512F	(1 << 16)
+#define bit_MPX (1 << 14)
+#define bit_RDSEED	(1 << 18)
+#define bit_ADX	(1 << 19)
+#define bit_AVX512PF	(1 << 26)
+#define bit_AVX512ER	(1 << 27)
+#define bit_AVX512CD	(1 << 28)
+#define bit_SHA		(1 << 29)
+
+/* Extended State Enumeration Sub-leaf (%eax == 13, %ecx == 1) */
+#define bit_XSAVEOPT	(1 << 0)
+
+/* Signatures for different CPU implementations as returned in uses
+   of cpuid with level 0.  */
+#define signature_AMD_ebx	0x68747541
+#define signature_AMD_ecx	0x444d4163
+#define signature_AMD_edx	0x69746e65
+
+#define signature_CENTAUR_ebx	0x746e6543
+#define signature_CENTAUR_ecx	0x736c7561
+#define signature_CENTAUR_edx	0x48727561
+
+#define signature_CYRIX_ebx	0x69727943
+#define signature_CYRIX_ecx	0x64616574
+#define signature_CYRIX_edx	0x736e4978
+
+#define signature_INTEL_ebx	0x756e6547
+#define signature_INTEL_ecx	0x6c65746e
+#define signature_INTEL_edx	0x49656e69
+
+#define signature_TM1_ebx	0x6e617254
+#define signature_TM1_ecx	0x55504361
+#define signature_TM1_edx	0x74656d73
+
+#define signature_TM2_ebx	0x756e6547
+#define signature_TM2_ecx	0x3638784d
+#define signature_TM2_edx	0x54656e69
+
+#define signature_NSC_ebx	0x646f6547
+#define signature_NSC_ecx	0x43534e20
+#define signature_NSC_edx	0x79622065
+
+#define signature_NEXGEN_ebx	0x4778654e
+#define signature_NEXGEN_ecx	0x6e657669
+#define signature_NEXGEN_edx	0x72446e65
+
+#define signature_RISE_ebx	0x65736952
+#define signature_RISE_ecx	0x65736952
+#define signature_RISE_edx	0x65736952
+
+#define signature_SIS_ebx	0x20536953
+#define signature_SIS_ecx	0x20536953
+#define signature_SIS_edx	0x20536953
+
+#define signature_UMC_ebx	0x20434d55
+#define signature_UMC_ecx	0x20434d55
+#define signature_UMC_edx	0x20434d55
+
+#define signature_VIA_ebx	0x20414956
+#define signature_VIA_ecx	0x20414956
+#define signature_VIA_edx	0x20414956
+
+#define signature_VORTEX_ebx	0x74726f56
+#define signature_VORTEX_ecx	0x436f5320
+#define signature_VORTEX_edx	0x36387865
+
+#if defined(__i386__) && defined(__PIC__)
+/* %ebx may be the PIC register.  */
+#if __GNUC__ >= 3
+#define __cpuid(level, a, b, c, d)			\
+  __asm__ ("xchg{l}\t{%%}ebx, %k1\n\t"			\
+	   "cpuid\n\t"					\
+	   "xchg{l}\t{%%}ebx, %k1\n\t"			\
+	   : "=a" (a), "=&r" (b), "=c" (c), "=d" (d)	\
+	   : "0" (level))
+
+#define __cpuid_count(level, count, a, b, c, d)		\
+  __asm__ ("xchg{l}\t{%%}ebx, %k1\n\t"			\
+	   "cpuid\n\t"					\
+	   "xchg{l}\t{%%}ebx, %k1\n\t"			\
+	   : "=a" (a), "=&r" (b), "=c" (c), "=d" (d)	\
+	   : "0" (level), "2" (count))
+#else
+/* Host GCCs older than 3.0 weren't supporting Intel asm syntax
+   nor alternatives in i386 code.  */
+#define __cpuid(level, a, b, c, d)			\
+  __asm__ ("xchgl\t%%ebx, %k1\n\t"			\
+	   "cpuid\n\t"					\
+	   "xchgl\t%%ebx, %k1\n\t"			\
+	   : "=a" (a), "=&r" (b), "=c" (c), "=d" (d)	\
+	   : "0" (level))
+
+#define __cpuid_count(level, count, a, b, c, d)		\
+  __asm__ ("xchgl\t%%ebx, %k1\n\t"			\
+	   "cpuid\n\t"					\
+	   "xchgl\t%%ebx, %k1\n\t"			\
+	   : "=a" (a), "=&r" (b), "=c" (c), "=d" (d)	\
+	   : "0" (level), "2" (count))
+#endif
+#elif defined(__x86_64__) && (defined(__code_model_medium__) || defined(__code_model_large__)) && defined(__PIC__)
+/* %rbx may be the PIC register.  */
+#define __cpuid(level, a, b, c, d)			\
+  __asm__ ("xchg{q}\t{%%}rbx, %q1\n\t"			\
+	   "cpuid\n\t"					\
+	   "xchg{q}\t{%%}rbx, %q1\n\t"			\
+	   : "=a" (a), "=&r" (b), "=c" (c), "=d" (d)	\
+	   : "0" (level))
+
+#define __cpuid_count(level, count, a, b, c, d)		\
+  __asm__ ("xchg{q}\t{%%}rbx, %q1\n\t"			\
+	   "cpuid\n\t"					\
+	   "xchg{q}\t{%%}rbx, %q1\n\t"			\
+	   : "=a" (a), "=&r" (b), "=c" (c), "=d" (d)	\
+	   : "0" (level), "2" (count))
+#else
+#define __cpuid(level, a, b, c, d)			\
+  __asm__ ("cpuid\n\t"					\
+	   : "=a" (a), "=b" (b), "=c" (c), "=d" (d)	\
+	   : "0" (level))
+
+#define __cpuid_count(level, count, a, b, c, d)		\
+  __asm__ ("cpuid\n\t"					\
+	   : "=a" (a), "=b" (b), "=c" (c), "=d" (d)	\
+	   : "0" (level), "2" (count))
+#endif
+
+/* Return highest supported input value for cpuid instruction.  ext can
+   be either 0x0 or 0x8000000 to return highest supported value for
+   basic or extended cpuid information.  Function returns 0 if cpuid
+   is not supported or whatever cpuid returns in eax register.  If sig
+   pointer is non-null, then first four bytes of the signature
+   (as found in ebx register) are returned in location pointed by sig.  */
+
+static __inline unsigned int
+__get_cpuid_max (unsigned int __ext, unsigned int *__sig)
+{
+  unsigned int __eax, __ebx, __ecx, __edx;
+
+#ifndef __x86_64__
+  /* See if we can use cpuid.  On AMD64 we always can.  */
+#if __GNUC__ >= 3
+  __asm__ ("pushf{l|d}\n\t"
+	   "pushf{l|d}\n\t"
+	   "pop{l}\t%0\n\t"
+	   "mov{l}\t{%0, %1|%1, %0}\n\t"
+	   "xor{l}\t{%2, %0|%0, %2}\n\t"
+	   "push{l}\t%0\n\t"
+	   "popf{l|d}\n\t"
+	   "pushf{l|d}\n\t"
+	   "pop{l}\t%0\n\t"
+	   "popf{l|d}\n\t"
+	   : "=&r" (__eax), "=&r" (__ebx)
+	   : "i" (0x00200000));
+#else
+/* Host GCCs older than 3.0 weren't supporting Intel asm syntax
+   nor alternatives in i386 code.  */
+  __asm__ ("pushfl\n\t"
+	   "pushfl\n\t"
+	   "popl\t%0\n\t"
+	   "movl\t%0, %1\n\t"
+	   "xorl\t%2, %0\n\t"
+	   "pushl\t%0\n\t"
+	   "popfl\n\t"
+	   "pushfl\n\t"
+	   "popl\t%0\n\t"
+	   "popfl\n\t"
+	   : "=&r" (__eax), "=&r" (__ebx)
+	   : "i" (0x00200000));
+#endif
+
+  if (!((__eax ^ __ebx) & 0x00200000))
+    return 0;
+#endif
+
+  /* Host supports cpuid.  Return highest supported cpuid input value.  */
+  __cpuid (__ext, __eax, __ebx, __ecx, __edx);
+
+  if (__sig)
+    *__sig = __ebx;
+
+  return __eax;
+}
+
+/* Return cpuid data for requested cpuid level, as found in returned
+   eax, ebx, ecx and edx registers.  The function checks if cpuid is
+   supported and returns 1 for valid cpuid information or 0 for
+   unsupported cpuid level.  All pointers are required to be non-null.  */
+
+static __inline int
+__get_cpuid (unsigned int __level,
+	     unsigned int *__eax, unsigned int *__ebx,
+	     unsigned int *__ecx, unsigned int *__edx)
+{
+  unsigned int __ext = __level & 0x80000000;
+
+  if (__get_cpuid_max (__ext, 0) < __level)
+    return 0;
+
+  __cpuid (__level, *__eax, *__ebx, *__ecx, *__edx);
+  return 1;
+}
diff --git a/gdb/nat/linux-btrace.c b/gdb/nat/linux-btrace.c
new file mode 100644
index 0000000..188220b
--- /dev/null
+++ b/gdb/nat/linux-btrace.c
@@ -0,0 +1,634 @@
+/* Linux-dependent part of branch trace support for GDB, and GDBserver.
+
+   Copyright (C) 2013-2014 Free Software Foundation, Inc.
+
+   Contributed by Intel Corp. <markus.t.metzger@intel.com>
+
+   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/>.  */
+
+#ifdef GDBSERVER
+#include "server.h"
+#else
+#include "defs.h"
+#endif
+
+#include "linux-btrace.h"
+#include "common-utils.h"
+#include "gdb_assert.h"
+#include "regcache.h"
+#include "gdbthread.h"
+#include "gdb_wait.h"
+#include "i386-cpuid.h"
+
+#ifdef HAVE_SYS_SYSCALL_H
+#include <sys/syscall.h>
+#endif
+
+#if HAVE_LINUX_PERF_EVENT_H && defined(SYS_perf_event_open)
+
+#include <errno.h>
+#include <string.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/user.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <signal.h>
+
+/* A branch trace record in perf_event.  */
+struct perf_event_bts
+{
+  /* The linear address of the branch source.  */
+  uint64_t from;
+
+  /* The linear address of the branch destination.  */
+  uint64_t to;
+};
+
+/* A perf_event branch trace sample.  */
+struct perf_event_sample
+{
+  /* The perf_event sample header.  */
+  struct perf_event_header header;
+
+  /* The perf_event branch tracing payload.  */
+  struct perf_event_bts bts;
+};
+
+/* Get the perf_event header.  */
+
+static inline volatile struct perf_event_mmap_page *
+perf_event_header (struct btrace_target_info* tinfo)
+{
+  return tinfo->buffer;
+}
+
+/* Get the size of the perf_event mmap buffer.  */
+
+static inline size_t
+perf_event_mmap_size (const struct btrace_target_info *tinfo)
+{
+  /* The branch trace buffer is preceded by a configuration page.  */
+  return (tinfo->size + 1) * PAGE_SIZE;
+}
+
+/* Get the size of the perf_event buffer.  */
+
+static inline size_t
+perf_event_buffer_size (struct btrace_target_info* tinfo)
+{
+  return tinfo->size * PAGE_SIZE;
+}
+
+/* Get the start address of the perf_event buffer.  */
+
+static inline const uint8_t *
+perf_event_buffer_begin (struct btrace_target_info* tinfo)
+{
+  return ((const uint8_t *) tinfo->buffer) + PAGE_SIZE;
+}
+
+/* Get the end address of the perf_event buffer.  */
+
+static inline const uint8_t *
+perf_event_buffer_end (struct btrace_target_info* tinfo)
+{
+  return perf_event_buffer_begin (tinfo) + perf_event_buffer_size (tinfo);
+}
+
+/* Check whether an address is in the kernel.  */
+
+static inline int
+perf_event_is_kernel_addr (const struct btrace_target_info *tinfo,
+			   uint64_t addr)
+{
+  uint64_t mask;
+
+  /* If we don't know the size of a pointer, we can't check.  Let's assume it's
+     not a kernel address in this case.  */
+  if (tinfo->ptr_bits == 0)
+    return 0;
+
+  /* A bit mask for the most significant bit in an address.  */
+  mask = (uint64_t) 1 << (tinfo->ptr_bits - 1);
+
+  /* Check whether the most significant bit in the address is set.  */
+  return (addr & mask) != 0;
+}
+
+/* Check whether a perf event record should be skipped.  */
+
+static inline int
+perf_event_skip_record (const struct btrace_target_info *tinfo,
+			const struct perf_event_bts *bts)
+{
+  /* The hardware may report branches from kernel into user space.  Branches
+     from user into kernel space will be suppressed.  We filter the former to
+     provide a consistent branch trace excluding kernel.  */
+  return perf_event_is_kernel_addr (tinfo, bts->from);
+}
+
+/* Perform a few consistency checks on a perf event sample record.  This is
+   meant to catch cases when we get out of sync with the perf event stream.  */
+
+static inline int
+perf_event_sample_ok (const struct perf_event_sample *sample)
+{
+  if (sample->header.type != PERF_RECORD_SAMPLE)
+    return 0;
+
+  if (sample->header.size != sizeof (*sample))
+    return 0;
+
+  return 1;
+}
+
+/* Branch trace is collected in a circular buffer [begin; end) as pairs of from
+   and to addresses (plus a header).
+
+   Start points into that buffer at the next sample position.
+   We read the collected samples backwards from start.
+
+   While reading the samples, we convert the information into a list of blocks.
+   For two adjacent samples s1 and s2, we form a block b such that b.begin =
+   s1.to and b.end = s2.from.
+
+   In case the buffer overflows during sampling, one sample may have its lower
+   part at the end and its upper part at the beginning of the buffer.  */
+
+static VEC (btrace_block_s) *
+perf_event_read_bts (struct btrace_target_info* tinfo, const uint8_t *begin,
+		     const uint8_t *end, const uint8_t *start, size_t size)
+{
+  VEC (btrace_block_s) *btrace = NULL;
+  struct perf_event_sample sample;
+  size_t read = 0;
+  struct btrace_block block = { 0, 0 };
+  struct regcache *regcache;
+
+  gdb_assert (begin <= start);
+  gdb_assert (start <= end);
+
+  /* The first block ends at the current pc.  */
+#ifdef GDBSERVER
+  regcache = get_thread_regcache (find_thread_ptid (tinfo->ptid), 1);
+#else
+  regcache = get_thread_regcache (tinfo->ptid);
+#endif
+  block.end = regcache_read_pc (regcache);
+
+  /* The buffer may contain a partial record as its last entry (i.e. when the
+     buffer size is not a multiple of the sample size).  */
+  read = sizeof (sample) - 1;
+
+  for (; read < size; read += sizeof (sample))
+    {
+      const struct perf_event_sample *psample;
+
+      /* Find the next perf_event sample in a backwards traversal.  */
+      start -= sizeof (sample);
+
+      /* If we're still inside the buffer, we're done.  */
+      if (begin <= start)
+	psample = (const struct perf_event_sample *) start;
+      else
+	{
+	  int missing;
+
+	  /* We're to the left of the ring buffer, we will wrap around and
+	     reappear at the very right of the ring buffer.  */
+
+	  missing = (begin - start);
+	  start = (end - missing);
+
+	  /* If the entire sample is missing, we're done.  */
+	  if (missing == sizeof (sample))
+	    psample = (const struct perf_event_sample *) start;
+	  else
+	    {
+	      uint8_t *stack;
+
+	      /* The sample wrapped around.  The lower part is at the end and
+		 the upper part is at the beginning of the buffer.  */
+	      stack = (uint8_t *) &sample;
+
+	      /* Copy the two parts so we have a contiguous sample.  */
+	      memcpy (stack, start, missing);
+	      memcpy (stack + missing, begin, sizeof (sample) - missing);
+
+	      psample = &sample;
+	    }
+	}
+
+      if (!perf_event_sample_ok (psample))
+	{
+	  warning (_("Branch trace may be incomplete."));
+	  break;
+	}
+
+      if (perf_event_skip_record (tinfo, &psample->bts))
+	continue;
+
+      /* We found a valid sample, so we can complete the current block.  */
+      block.begin = psample->bts.to;
+
+      VEC_safe_push (btrace_block_s, btrace, &block);
+
+      /* Start the next block.  */
+      block.end = psample->bts.from;
+    }
+
+  /* Push the last block (i.e. the first one of inferior execution), as well.
+     We don't know where it ends, but we know where it starts.  If we're
+     reading delta trace, we can fill in the start address later on.
+     Otherwise we will prune it.  */
+  block.begin = 0;
+  VEC_safe_push (btrace_block_s, btrace, &block);
+
+  return btrace;
+}
+
+/* Check whether the kernel supports branch tracing.  */
+
+static int
+kernel_supports_btrace (void)
+{
+  struct perf_event_attr attr;
+  pid_t child, pid;
+  int status, file;
+
+  errno = 0;
+  child = fork ();
+  switch (child)
+    {
+    case -1:
+      warning (_("test branch tracing: cannot fork: %s."), strerror (errno));
+      return 0;
+
+    case 0:
+      status = ptrace (PTRACE_TRACEME, 0, NULL, NULL);
+      if (status != 0)
+	{
+	  warning (_("test branch tracing: cannot PTRACE_TRACEME: %s."),
+		   strerror (errno));
+	  _exit (1);
+	}
+
+      status = raise (SIGTRAP);
+      if (status != 0)
+	{
+	  warning (_("test branch tracing: cannot raise SIGTRAP: %s."),
+		   strerror (errno));
+	  _exit (1);
+	}
+
+      _exit (1);
+
+    default:
+      pid = waitpid (child, &status, 0);
+      if (pid != child)
+	{
+	  warning (_("test branch tracing: bad pid %ld, error: %s."),
+		   (long) pid, strerror (errno));
+	  return 0;
+	}
+
+      if (!WIFSTOPPED (status))
+	{
+	  warning (_("test branch tracing: expected stop. status: %d."),
+		   status);
+	  return 0;
+	}
+
+      memset (&attr, 0, sizeof (attr));
+
+      attr.type = PERF_TYPE_HARDWARE;
+      attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS;
+      attr.sample_period = 1;
+      attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR;
+      attr.exclude_kernel = 1;
+      attr.exclude_hv = 1;
+      attr.exclude_idle = 1;
+
+      file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0);
+      if (file >= 0)
+	close (file);
+
+      kill (child, SIGKILL);
+      ptrace (PTRACE_KILL, child, NULL, NULL);
+
+      pid = waitpid (child, &status, 0);
+      if (pid != child)
+	{
+	  warning (_("test branch tracing: bad pid %ld, error: %s."),
+		   (long) pid, strerror (errno));
+	  if (!WIFSIGNALED (status))
+	    warning (_("test branch tracing: expected killed. status: %d."),
+		     status);
+	}
+
+      return (file >= 0);
+    }
+}
+
+/* Check whether an Intel cpu supports branch tracing.  */
+
+static int
+intel_supports_btrace (void)
+{
+  unsigned int cpuid, model, family;
+
+  if (!i386_cpuid (1, &cpuid, NULL, NULL, NULL))
+    return 0;
+
+  family = (cpuid >> 8) & 0xf;
+  model = (cpuid >> 4) & 0xf;
+
+  switch (family)
+    {
+    case 0x6:
+      model += (cpuid >> 12) & 0xf0;
+
+      switch (model)
+	{
+	case 0x1a: /* Nehalem */
+	case 0x1f:
+	case 0x1e:
+	case 0x2e:
+	case 0x25: /* Westmere */
+	case 0x2c:
+	case 0x2f:
+	case 0x2a: /* Sandy Bridge */
+	case 0x2d:
+	case 0x3a: /* Ivy Bridge */
+
+	  /* AAJ122: LBR, BTM, or BTS records may have incorrect branch
+	     "from" information afer an EIST transition, T-states, C1E, or
+	     Adaptive Thermal Throttling.  */
+	  return 0;
+	}
+    }
+
+  return 1;
+}
+
+/* Check whether the cpu supports branch tracing.  */
+
+static int
+cpu_supports_btrace (void)
+{
+  unsigned int ebx, ecx, edx;
+
+  if (!i386_cpuid (0, NULL, &ebx, &ecx, &edx))
+    return 0;
+
+  if (ebx == signature_INTEL_ebx && ecx == signature_INTEL_ecx
+      && edx == signature_INTEL_edx)
+    return intel_supports_btrace ();
+
+  /* Don't know about others.  Let's assume they do.  */
+  return 1;
+}
+
+/* See linux-btrace.h.  */
+
+int
+linux_supports_btrace (struct target_ops *ops)
+{
+  static int cached;
+
+  if (cached == 0)
+    {
+      if (!kernel_supports_btrace ())
+	cached = -1;
+      else if (!cpu_supports_btrace ())
+	cached = -1;
+      else
+	cached = 1;
+    }
+
+  return cached > 0;
+}
+
+/* See linux-btrace.h.  */
+
+struct btrace_target_info *
+linux_enable_btrace (ptid_t ptid)
+{
+  struct btrace_target_info *tinfo;
+  int pid, pg;
+
+  tinfo = xzalloc (sizeof (*tinfo));
+  tinfo->ptid = ptid;
+
+  tinfo->attr.size = sizeof (tinfo->attr);
+  tinfo->attr.type = PERF_TYPE_HARDWARE;
+  tinfo->attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS;
+  tinfo->attr.sample_period = 1;
+
+  /* We sample from and to address.  */
+  tinfo->attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR;
+
+  tinfo->attr.exclude_kernel = 1;
+  tinfo->attr.exclude_hv = 1;
+  tinfo->attr.exclude_idle = 1;
+
+  tinfo->ptr_bits = 0;
+
+  pid = ptid_get_lwp (ptid);
+  if (pid == 0)
+    pid = ptid_get_pid (ptid);
+
+  errno = 0;
+  tinfo->file = syscall (SYS_perf_event_open, &tinfo->attr, pid, -1, -1, 0);
+  if (tinfo->file < 0)
+    goto err;
+
+  /* We try to allocate as much buffer as we can get.
+     We could allow the user to specify the size of the buffer, but then
+     we'd leave this search for the maximum buffer size to him.  */
+  for (pg = 4; pg >= 0; --pg)
+    {
+      /* The number of pages we request needs to be a power of two.  */
+      tinfo->size = 1 << pg;
+      tinfo->buffer = mmap (NULL, perf_event_mmap_size (tinfo),
+			    PROT_READ, MAP_SHARED, tinfo->file, 0);
+      if (tinfo->buffer == MAP_FAILED)
+	continue;
+
+      return tinfo;
+    }
+
+  /* We were not able to allocate any buffer.  */
+  close (tinfo->file);
+
+ err:
+  xfree (tinfo);
+  return NULL;
+}
+
+/* See linux-btrace.h.  */
+
+enum btrace_error
+linux_disable_btrace (struct btrace_target_info *tinfo)
+{
+  int errcode;
+
+  errno = 0;
+  errcode = munmap (tinfo->buffer, perf_event_mmap_size (tinfo));
+  if (errcode != 0)
+    return BTRACE_ERR_UNKNOWN;
+
+  close (tinfo->file);
+  xfree (tinfo);
+
+  return BTRACE_ERR_NONE;
+}
+
+/* Check whether the branch trace has changed.  */
+
+static int
+linux_btrace_has_changed (struct btrace_target_info *tinfo)
+{
+  volatile struct perf_event_mmap_page *header = perf_event_header (tinfo);
+
+  return header->data_head != tinfo->data_head;
+}
+
+/* See linux-btrace.h.  */
+
+enum btrace_error
+linux_read_btrace (VEC (btrace_block_s) **btrace,
+		   struct btrace_target_info *tinfo,
+		   enum btrace_read_type type)
+{
+  volatile struct perf_event_mmap_page *header;
+  const uint8_t *begin, *end, *start;
+  unsigned long data_head, data_tail, retries = 5;
+  size_t buffer_size, size;
+
+  /* For delta reads, we return at least the partial last block containing
+     the current PC.  */
+  if (type == BTRACE_READ_NEW && !linux_btrace_has_changed (tinfo))
+    return BTRACE_ERR_NONE;
+
+  header = perf_event_header (tinfo);
+  buffer_size = perf_event_buffer_size (tinfo);
+  data_tail = tinfo->data_head;
+
+  /* We may need to retry reading the trace.  See below.  */
+  while (retries--)
+    {
+      data_head = header->data_head;
+
+      /* Delete any leftover trace from the previous iteration.  */
+      VEC_free (btrace_block_s, *btrace);
+
+      if (type == BTRACE_READ_DELTA)
+	{
+	  /* Determine the number of bytes to read and check for buffer
+	     overflows.  */
+
+	  /* Check for data head overflows.  We might be able to recover from
+	     those but they are very unlikely and it's not really worth the
+	     effort, I think.  */
+	  if (data_head < data_tail)
+	    return BTRACE_ERR_OVERFLOW;
+
+	  /* If the buffer is smaller than the trace delta, we overflowed.  */
+	  size = data_head - data_tail;
+	  if (buffer_size < size)
+	    return BTRACE_ERR_OVERFLOW;
+	}
+      else
+	{
+	  /* Read the entire buffer.  */
+	  size = buffer_size;
+
+	  /* Adjust the size if the buffer has not overflowed, yet.  */
+	  if (data_head < size)
+	    size = data_head;
+	}
+
+      /* Data_head keeps growing; the buffer itself is circular.  */
+      begin = perf_event_buffer_begin (tinfo);
+      start = begin + data_head % buffer_size;
+
+      if (data_head <= buffer_size)
+	end = start;
+      else
+	end = perf_event_buffer_end (tinfo);
+
+      *btrace = perf_event_read_bts (tinfo, begin, end, start, size);
+
+      /* The stopping thread notifies its ptracer before it is scheduled out.
+	 On multi-core systems, the debugger might therefore run while the
+	 kernel might be writing the last branch trace records.
+
+	 Let's check whether the data head moved while we read the trace.  */
+      if (data_head == header->data_head)
+	break;
+    }
+
+  tinfo->data_head = data_head;
+
+  /* Prune the incomplete last block (i.e. the first one of inferior execution)
+     if we're not doing a delta read.  There is no way of filling in its zeroed
+     BEGIN element.  */
+  if (!VEC_empty (btrace_block_s, *btrace) && type != BTRACE_READ_DELTA)
+    VEC_pop (btrace_block_s, *btrace);
+
+  return BTRACE_ERR_NONE;
+}
+
+#else /* !HAVE_LINUX_PERF_EVENT_H */
+
+/* See linux-btrace.h.  */
+
+int
+linux_supports_btrace (struct target_ops *ops)
+{
+  return 0;
+}
+
+/* See linux-btrace.h.  */
+
+struct btrace_target_info *
+linux_enable_btrace (ptid_t ptid)
+{
+  return NULL;
+}
+
+/* See linux-btrace.h.  */
+
+enum btrace_error
+linux_disable_btrace (struct btrace_target_info *tinfo)
+{
+  return BTRACE_ERR_NOT_SUPPORTED;
+}
+
+/* See linux-btrace.h.  */
+
+enum btrace_error
+linux_read_btrace (VEC (btrace_block_s) **btrace,
+		   struct btrace_target_info *tinfo,
+		   enum btrace_read_type type)
+{
+  return BTRACE_ERR_NOT_SUPPORTED;
+}
+
+#endif /* !HAVE_LINUX_PERF_EVENT_H */
diff --git a/gdb/nat/linux-btrace.h b/gdb/nat/linux-btrace.h
new file mode 100644
index 0000000..12e9b60
--- /dev/null
+++ b/gdb/nat/linux-btrace.h
@@ -0,0 +1,78 @@
+/* Linux-dependent part of branch trace support for GDB, and GDBserver.
+
+   Copyright (C) 2013-2014 Free Software Foundation, Inc.
+
+   Contributed by Intel Corp. <markus.t.metzger@intel.com>
+
+   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 LINUX_BTRACE_H
+#define LINUX_BTRACE_H
+
+#include "btrace-common.h"
+#include "config.h"
+#include "vec.h"
+#include "ptid.h"
+#include <stddef.h>
+#include <stdint.h>
+
+#if HAVE_LINUX_PERF_EVENT_H
+#  include <linux/perf_event.h>
+#endif
+
+/* Branch trace target information per thread.  */
+struct btrace_target_info
+{
+#if HAVE_LINUX_PERF_EVENT_H
+  /* The Linux perf_event configuration for collecting the branch trace.  */
+  struct perf_event_attr attr;
+
+  /* The ptid of this thread.  */
+  ptid_t ptid;
+
+  /* The mmap configuration mapping the branch trace perf_event buffer.
+
+     file      .. the file descriptor
+     buffer    .. the mmapped memory buffer
+     size      .. the buffer's size in pages without the configuration page
+     data_head .. the data head from the last read  */
+  int file;
+  void *buffer;
+  size_t size;
+  unsigned long data_head;
+#endif /* HAVE_LINUX_PERF_EVENT_H */
+
+  /* The size of a pointer in bits for this thread.
+     The information is used to identify kernel addresses in order to skip
+     records from/to kernel space.  */
+  int ptr_bits;
+};
+
+/* See to_supports_btrace in target.h.  */
+extern int linux_supports_btrace (struct target_ops *);
+
+/* See to_enable_btrace in target.h.  */
+extern struct btrace_target_info *linux_enable_btrace (ptid_t ptid);
+
+/* See to_disable_btrace in target.h.  */
+extern enum btrace_error linux_disable_btrace (struct btrace_target_info *ti);
+
+/* See to_read_btrace in target.h.  */
+extern enum btrace_error linux_read_btrace (VEC (btrace_block_s) **btrace,
+					    struct btrace_target_info *btinfo,
+					    enum btrace_read_type type);
+
+#endif /* LINUX_BTRACE_H */
diff --git a/gdb/nat/linux-osdata.c b/gdb/nat/linux-osdata.c
new file mode 100644
index 0000000..dae637b
--- /dev/null
+++ b/gdb/nat/linux-osdata.c
@@ -0,0 +1,1634 @@
+/* Linux-specific functions to retrieve OS data.
+   
+   Copyright (C) 2009-2014 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/>.  */
+
+#ifdef GDBSERVER
+#include "server.h"
+#else
+#include "defs.h"
+#endif
+
+#include "linux-osdata.h"
+
+#include <sys/types.h>
+#include <sys/sysinfo.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <utmp.h>
+#include <time.h>
+#include <unistd.h>
+#include <pwd.h>
+#include <grp.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include "xml-utils.h"
+#include "buffer.h"
+#include "gdb_assert.h"
+#include <dirent.h>
+#include <sys/stat.h>
+#include "filestuff.h"
+
+#define NAMELEN(dirent) strlen ((dirent)->d_name)
+
+/* Define PID_T to be a fixed size that is at least as large as pid_t,
+   so that reading pid values embedded in /proc works
+   consistently.  */
+
+typedef long long  PID_T;
+
+/* Define TIME_T to be at least as large as time_t, so that reading
+   time values embedded in /proc works consistently.  */
+
+typedef long long TIME_T;
+
+#define MAX_PID_T_STRLEN  (sizeof ("-9223372036854775808") - 1)
+
+/* Returns the CPU core that thread PTID is currently running on.  */
+					  
+/* Compute and return the processor core of a given thread.  */
+
+int
+linux_common_core_of_thread (ptid_t ptid)
+{
+  char filename[sizeof ("/proc//task//stat") + 2 * MAX_PID_T_STRLEN];
+  FILE *f;
+  char *content = NULL;
+  char *p;
+  char *ts = 0;
+  int content_read = 0;
+  int i;
+  int core;
+
+  sprintf (filename, "/proc/%lld/task/%lld/stat",
+	   (PID_T) ptid_get_pid (ptid), (PID_T) ptid_get_lwp (ptid));
+  f = gdb_fopen_cloexec (filename, "r");
+  if (!f)
+    return -1;
+
+  for (;;)
+    {
+      int n;
+      content = xrealloc (content, content_read + 1024);
+      n = fread (content + content_read, 1, 1024, f);
+      content_read += n;
+      if (n < 1024)
+	{
+	  content[content_read] = '\0';
+	  break;
+	}
+    }
+
+  /* ps command also relies on no trailing fields ever contain ')'.  */
+  p = strrchr (content, ')');
+  if (p != NULL)
+    p++;
+
+  /* If the first field after program name has index 0, then core number is
+     the field with index 36.  There's no constant for that anywhere.  */
+  if (p != NULL)
+    p = strtok_r (p, " ", &ts);
+  for (i = 0; p != NULL && i != 36; ++i)
+    p = strtok_r (NULL, " ", &ts);
+
+  if (p == NULL || sscanf (p, "%d", &core) == 0)
+    core = -1;
+
+  xfree (content);
+  fclose (f);
+
+  return core;
+}
+
+/* Finds the command-line of process PID and copies it into COMMAND.
+   At most MAXLEN characters are copied.  If the command-line cannot
+   be found, PID is copied into command in text-form.  */
+
+static void
+command_from_pid (char *command, int maxlen, PID_T pid)
+{
+  char *stat_path = xstrprintf ("/proc/%lld/stat", pid); 
+  FILE *fp = gdb_fopen_cloexec (stat_path, "r");
+  
+  command[0] = '\0';
+ 
+  if (fp)
+    {
+      /* sizeof (cmd) should be greater or equal to TASK_COMM_LEN (in
+	 include/linux/sched.h in the Linux kernel sources) plus two
+	 (for the brackets).  */
+      char cmd[18];
+      PID_T stat_pid;
+      int items_read = fscanf (fp, "%lld %17s", &stat_pid, cmd);
+	  
+      if (items_read == 2 && pid == stat_pid)
+	{
+	  cmd[strlen (cmd) - 1] = '\0'; /* Remove trailing parenthesis.  */
+	  strncpy (command, cmd + 1, maxlen); /* Ignore leading parenthesis.  */
+	}
+
+      fclose (fp);
+    }
+  else
+    {
+      /* Return the PID if a /proc entry for the process cannot be found.  */
+      snprintf (command, maxlen, "%lld", pid);
+    }
+
+  command[maxlen - 1] = '\0'; /* Ensure string is null-terminated.  */
+	
+  xfree (stat_path);
+}
+
+/* Returns the command-line of the process with the given PID. The
+   returned string needs to be freed using xfree after use.  */
+
+static char *
+commandline_from_pid (PID_T pid)
+{
+  char *pathname = xstrprintf ("/proc/%lld/cmdline", pid);
+  char *commandline = NULL;
+  FILE *f = gdb_fopen_cloexec (pathname, "r");
+
+  if (f)
+    {
+      size_t len = 0;
+
+      while (!feof (f))
+	{
+	  char buf[1024];
+	  size_t read_bytes = fread (buf, 1, sizeof (buf), f);
+     
+	  if (read_bytes)
+	    {
+	      commandline = (char *) xrealloc (commandline, len + read_bytes + 1);
+	      memcpy (commandline + len, buf, read_bytes);
+	      len += read_bytes;
+	    }
+	}
+
+      fclose (f);
+
+      if (commandline)
+	{
+	  size_t i;
+
+	  /* Replace null characters with spaces.  */
+	  for (i = 0; i < len; ++i)
+	    if (commandline[i] == '\0')
+	      commandline[i] = ' ';
+
+	  commandline[len] = '\0';
+	}
+      else
+	{
+	  /* Return the command in square brackets if the command-line
+	     is empty.  */
+	  commandline = (char *) xmalloc (32);
+	  commandline[0] = '[';
+	  command_from_pid (commandline + 1, 31, pid);
+
+	  len = strlen (commandline);
+	  if (len < 31)
+	    strcat (commandline, "]");
+	}
+    }
+
+  xfree (pathname);
+
+  return commandline;
+}
+
+/* Finds the user name for the user UID and copies it into USER.  At
+   most MAXLEN characters are copied.  */
+
+static void
+user_from_uid (char *user, int maxlen, uid_t uid)
+{
+  struct passwd *pwentry = getpwuid (uid);
+  
+  if (pwentry)
+    {
+      strncpy (user, pwentry->pw_name, maxlen);
+      /* Ensure that the user name is null-terminated.  */
+      user[maxlen - 1] = '\0';
+    }
+  else
+    user[0] = '\0';
+}
+
+/* Finds the owner of process PID and returns the user id in OWNER.
+   Returns 0 if the owner was found, -1 otherwise.  */
+
+static int
+get_process_owner (uid_t *owner, PID_T pid)
+{
+  struct stat statbuf;
+  char procentry[sizeof ("/proc/") + MAX_PID_T_STRLEN];
+
+  sprintf (procentry, "/proc/%lld", pid);
+  
+  if (stat (procentry, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
+    {
+      *owner = statbuf.st_uid;
+      return 0;
+    }
+  else
+    return -1;
+}
+
+/* Find the CPU cores used by process PID and return them in CORES.
+   CORES points to an array of NUM_CORES elements.  */
+
+static int
+get_cores_used_by_process (PID_T pid, int *cores, const int num_cores)
+{
+  char taskdir[sizeof ("/proc/") + MAX_PID_T_STRLEN + sizeof ("/task") - 1];
+  DIR *dir;
+  struct dirent *dp;
+  int task_count = 0;
+
+  sprintf (taskdir, "/proc/%lld/task", pid);
+  dir = opendir (taskdir);
+  if (dir)
+    {
+      while ((dp = readdir (dir)) != NULL)
+	{
+	  PID_T tid;
+	  int core;
+
+	  if (!isdigit (dp->d_name[0])
+	      || NAMELEN (dp) > MAX_PID_T_STRLEN)
+	    continue;
+
+	  sscanf (dp->d_name, "%lld", &tid);
+	  core = linux_common_core_of_thread (ptid_build ((pid_t) pid,
+							  (pid_t) tid, 0));
+
+	  if (core >= 0 && core < num_cores)
+	    {
+	      ++cores[core];
+	      ++task_count;
+	    }
+	}
+
+      closedir (dir);
+    }
+
+  return task_count;
+}
+
+static LONGEST
+linux_xfer_osdata_processes (gdb_byte *readbuf,
+			     ULONGEST offset, ULONGEST len)
+{
+  /* We make the process list snapshot when the object starts to be read.  */
+  static const char *buf;
+  static LONGEST len_avail = -1;
+  static struct buffer buffer;
+
+  if (offset == 0)
+    {
+      DIR *dirp;
+
+      if (len_avail != -1 && len_avail != 0)
+	buffer_free (&buffer);
+      len_avail = 0;
+      buf = NULL;
+      buffer_init (&buffer);
+      buffer_grow_str (&buffer, "<osdata type=\"processes\">\n");
+
+      dirp = opendir ("/proc");
+      if (dirp)
+	{
+	  const int num_cores = sysconf (_SC_NPROCESSORS_ONLN);
+	  struct dirent *dp;
+
+	  while ((dp = readdir (dirp)) != NULL)
+	    {
+	      PID_T pid;
+	      uid_t owner;
+	      char user[UT_NAMESIZE];
+	      char *command_line;
+	      int *cores;
+	      int task_count;
+	      char *cores_str;
+	      int i;
+
+	      if (!isdigit (dp->d_name[0])
+		  || NAMELEN (dp) > MAX_PID_T_STRLEN)
+		continue;
+
+	      sscanf (dp->d_name, "%lld", &pid);
+	      command_line = commandline_from_pid (pid);
+
+	      if (get_process_owner (&owner, pid) == 0)
+		user_from_uid (user, sizeof (user), owner);
+	      else
+		strcpy (user, "?");
+
+	      /* Find CPU cores used by the process.  */
+	      cores = (int *) xcalloc (num_cores, sizeof (int));
+	      task_count = get_cores_used_by_process (pid, cores, num_cores);
+	      cores_str = (char *) xcalloc (task_count, sizeof ("4294967295") + 1);
+
+	      for (i = 0; i < num_cores && task_count > 0; ++i)
+		if (cores[i])
+		  {
+		    char core_str[sizeof ("4294967295")];
+
+		    sprintf (core_str, "%d", i);
+		    strcat (cores_str, core_str);
+
+		    task_count -= cores[i];
+		    if (task_count > 0)
+		      strcat (cores_str, ",");
+		  }
+
+	      xfree (cores);
+	      
+	      buffer_xml_printf (
+		  &buffer,
+		  "<item>"
+		  "<column name=\"pid\">%lld</column>"
+		  "<column name=\"user\">%s</column>"
+		  "<column name=\"command\">%s</column>"
+		  "<column name=\"cores\">%s</column>"
+		  "</item>",
+		  pid,
+		  user,
+		  command_line ? command_line : "",
+		  cores_str);
+
+	      xfree (command_line);     
+	      xfree (cores_str);
+	    }
+	  
+	  closedir (dirp);
+	}
+
+      buffer_grow_str0 (&buffer, "</osdata>\n");
+      buf = buffer_finish (&buffer);
+      len_avail = strlen (buf);
+    }
+
+  if (offset >= len_avail)
+    {
+      /* Done.  Get rid of the buffer.  */
+      buffer_free (&buffer);
+      buf = NULL;
+      len_avail = 0;
+      return 0;
+    }
+
+  if (len > len_avail - offset)
+    len = len_avail - offset;
+  memcpy (readbuf, buf + offset, len);
+
+  return len;
+}
+
+/* Auxiliary function used by qsort to sort processes by process
+   group.  Compares two processes with ids PROCESS1 and PROCESS2.
+   PROCESS1 comes before PROCESS2 if it has a lower process group id.
+   If they belong to the same process group, PROCESS1 comes before
+   PROCESS2 if it has a lower process id or is the process group
+   leader.  */
+
+static int
+compare_processes (const void *process1, const void *process2)
+{
+  PID_T pid1 = *((PID_T *) process1);
+  PID_T pid2 = *((PID_T *) process2);
+  PID_T pgid1 = *((PID_T *) process1 + 1);
+  PID_T pgid2 = *((PID_T *) process2 + 1);
+
+  /* Sort by PGID.  */
+  if (pgid1 < pgid2)
+    return -1;
+  else if (pgid1 > pgid2)
+    return 1;
+  else
+    {
+      /* Process group leaders always come first, else sort by PID.  */
+      if (pid1 == pgid1)
+	return -1;
+      else if (pid2 == pgid2)
+	return 1;
+      else if (pid1 < pid2)
+	return -1;
+      else if (pid1 > pid2)
+	return 1;
+      else
+	return 0;
+    }
+}
+
+/* Collect all process groups from /proc.  */
+
+static LONGEST
+linux_xfer_osdata_processgroups (gdb_byte *readbuf,
+				 ULONGEST offset, ULONGEST len)
+{
+  /* We make the process list snapshot when the object starts to be read.  */
+  static const char *buf;
+  static LONGEST len_avail = -1;
+  static struct buffer buffer;
+
+  if (offset == 0)
+    {
+      DIR *dirp;
+
+      if (len_avail != -1 && len_avail != 0)
+	buffer_free (&buffer);
+      len_avail = 0;
+      buf = NULL;
+      buffer_init (&buffer);
+      buffer_grow_str (&buffer, "<osdata type=\"process groups\">\n");
+
+      dirp = opendir ("/proc");
+      if (dirp)
+	{
+	  struct dirent *dp;
+	  const size_t list_block_size = 512;
+	  PID_T *process_list = (PID_T *) xmalloc (list_block_size * 2 * sizeof (PID_T));
+	  size_t process_count = 0;
+	  size_t i;
+
+	  /* Build list consisting of PIDs followed by their
+	     associated PGID.  */
+	  while ((dp = readdir (dirp)) != NULL)
+	    {
+	      PID_T pid, pgid;
+
+	      if (!isdigit (dp->d_name[0])
+		  || NAMELEN (dp) > MAX_PID_T_STRLEN)
+		continue;
+
+	      sscanf (dp->d_name, "%lld", &pid);
+	      pgid = getpgid (pid);
+
+	      if (pgid > 0)
+		{
+		  process_list[2 * process_count] = pid;
+		  process_list[2 * process_count + 1] = pgid;
+		  ++process_count;
+
+		  /* Increase the size of the list if necessary.  */
+		  if (process_count % list_block_size == 0)
+		    process_list = (PID_T *) xrealloc (
+			process_list,
+			(process_count + list_block_size)
+			* 2 * sizeof (PID_T));
+		}
+	    }
+
+	  closedir (dirp);
+
+	  /* Sort the process list.  */
+	  qsort (process_list, process_count, 2 * sizeof (PID_T),
+		 compare_processes);
+
+	  for (i = 0; i < process_count; ++i)
+	    {
+	      PID_T pid = process_list[2 * i];
+	      PID_T pgid = process_list[2 * i + 1];
+	      char leader_command[32];
+	      char *command_line;
+
+	      command_from_pid (leader_command, sizeof (leader_command), pgid);
+	      command_line = commandline_from_pid (pid);
+
+	      buffer_xml_printf (
+		  &buffer,
+		  "<item>"
+		  "<column name=\"pgid\">%lld</column>"
+		  "<column name=\"leader command\">%s</column>"
+		  "<column name=\"pid\">%lld</column>"
+		  "<column name=\"command line\">%s</column>"
+		  "</item>",
+		  pgid,
+		  leader_command,
+		  pid,
+		  command_line ? command_line : "");
+
+	      xfree (command_line);
+	    }
+
+	  xfree (process_list);
+	}   
+
+      buffer_grow_str0 (&buffer, "</osdata>\n");
+      buf = buffer_finish (&buffer);
+      len_avail = strlen (buf);
+    }
+
+  if (offset >= len_avail)
+    {
+      /* Done.  Get rid of the buffer.  */
+      buffer_free (&buffer);
+      buf = NULL;
+      len_avail = 0;
+      return 0;
+    }
+
+  if (len > len_avail - offset)
+    len = len_avail - offset;
+  memcpy (readbuf, buf + offset, len);
+
+  return len;
+}
+
+/* Collect all the threads in /proc by iterating through processes and
+   then tasks within each process.  */
+
+static LONGEST
+linux_xfer_osdata_threads (gdb_byte *readbuf,
+			   ULONGEST offset, ULONGEST len)
+{
+  /* We make the process list snapshot when the object starts to be read.  */
+  static const char *buf;
+  static LONGEST len_avail = -1;
+  static struct buffer buffer;
+
+  if (offset == 0)
+    {
+      DIR *dirp;
+
+      if (len_avail != -1 && len_avail != 0)
+	buffer_free (&buffer);
+      len_avail = 0;
+      buf = NULL;
+      buffer_init (&buffer);
+      buffer_grow_str (&buffer, "<osdata type=\"threads\">\n");
+
+      dirp = opendir ("/proc");
+      if (dirp)
+	{
+	  struct dirent *dp;
+
+	  while ((dp = readdir (dirp)) != NULL)
+	    {
+	      struct stat statbuf;
+	      char procentry[sizeof ("/proc/4294967295")];
+
+	      if (!isdigit (dp->d_name[0])
+		  || NAMELEN (dp) > sizeof ("4294967295") - 1)
+		continue;
+
+	      sprintf (procentry, "/proc/%s", dp->d_name);
+	      if (stat (procentry, &statbuf) == 0
+		  && S_ISDIR (statbuf.st_mode))
+		{
+		  DIR *dirp2;
+		  char *pathname;
+		  PID_T pid;
+		  char command[32];
+
+		  pathname = xstrprintf ("/proc/%s/task", dp->d_name);
+		  
+		  pid = atoi (dp->d_name);
+		  command_from_pid (command, sizeof (command), pid);
+
+		  dirp2 = opendir (pathname);
+
+		  if (dirp2)
+		    {
+		      struct dirent *dp2;
+
+		      while ((dp2 = readdir (dirp2)) != NULL)
+			{
+			  PID_T tid;
+			  int core;
+
+			  if (!isdigit (dp2->d_name[0])
+			      || NAMELEN (dp2) > sizeof ("4294967295") - 1)
+			    continue;
+
+			  tid = atoi (dp2->d_name);
+			  core = linux_common_core_of_thread (ptid_build (pid, tid, 0));
+
+			  buffer_xml_printf (
+			    &buffer,
+			    "<item>"
+			    "<column name=\"pid\">%lld</column>"
+			    "<column name=\"command\">%s</column>"
+			    "<column name=\"tid\">%lld</column>"
+			    "<column name=\"core\">%d</column>"
+			    "</item>",
+			    pid,
+			    command,
+			    tid,
+			    core);
+			}
+
+		      closedir (dirp2);
+		    }
+
+		  xfree (pathname);
+		}
+	    }
+
+	  closedir (dirp);
+	}
+
+      buffer_grow_str0 (&buffer, "</osdata>\n");
+      buf = buffer_finish (&buffer);
+      len_avail = strlen (buf);
+    }
+
+  if (offset >= len_avail)
+    {
+      /* Done.  Get rid of the buffer.  */
+      buffer_free (&buffer);
+      buf = NULL;
+      len_avail = 0;
+      return 0;
+    }
+
+  if (len > len_avail - offset)
+    len = len_avail - offset;
+  memcpy (readbuf, buf + offset, len);
+
+  return len;
+}
+
+/* Collect all the open file descriptors found in /proc and put the details
+   found about them into READBUF.  */
+
+static LONGEST
+linux_xfer_osdata_fds (gdb_byte *readbuf,
+		       ULONGEST offset, ULONGEST len)
+{
+  /* We make the process list snapshot when the object starts to be read.  */
+  static const char *buf;
+  static LONGEST len_avail = -1;
+  static struct buffer buffer;
+
+  if (offset == 0)
+    {
+      DIR *dirp;
+
+      if (len_avail != -1 && len_avail != 0)
+	buffer_free (&buffer);
+      len_avail = 0;
+      buf = NULL;
+      buffer_init (&buffer);
+      buffer_grow_str (&buffer, "<osdata type=\"files\">\n");
+
+      dirp = opendir ("/proc");
+      if (dirp)
+	{
+	  struct dirent *dp;
+
+	  while ((dp = readdir (dirp)) != NULL)
+	    {
+	      struct stat statbuf;
+	      char procentry[sizeof ("/proc/4294967295")];
+
+	      if (!isdigit (dp->d_name[0])
+		  || NAMELEN (dp) > sizeof ("4294967295") - 1)
+		continue;
+
+	      sprintf (procentry, "/proc/%s", dp->d_name);
+	      if (stat (procentry, &statbuf) == 0
+		  && S_ISDIR (statbuf.st_mode))
+		{
+		  char *pathname;
+		  DIR *dirp2;
+		  PID_T pid;
+		  char command[32];
+
+		  pid = atoi (dp->d_name);
+		  command_from_pid (command, sizeof (command), pid);
+
+		  pathname = xstrprintf ("/proc/%s/fd", dp->d_name);
+		  dirp2 = opendir (pathname);
+
+		  if (dirp2)
+		    {
+		      struct dirent *dp2;
+
+		      while ((dp2 = readdir (dirp2)) != NULL)
+			{
+			  char *fdname;
+			  char buf[1000];
+			  ssize_t rslt;
+
+			  if (!isdigit (dp2->d_name[0]))
+			    continue;
+
+			  fdname = xstrprintf ("%s/%s", pathname, dp2->d_name);
+			  rslt = readlink (fdname, buf, sizeof (buf) - 1);
+			  if (rslt >= 0)
+			    buf[rslt] = '\0';
+
+			  buffer_xml_printf (
+			    &buffer,
+			    "<item>"
+			    "<column name=\"pid\">%s</column>"
+			    "<column name=\"command\">%s</column>"
+			    "<column name=\"file descriptor\">%s</column>"
+			    "<column name=\"name\">%s</column>"
+			    "</item>",
+			    dp->d_name,
+			    command,
+			    dp2->d_name,
+			    (rslt >= 0 ? buf : dp2->d_name));
+			}
+
+		      closedir (dirp2);
+		    }
+
+		  xfree (pathname);
+		}
+	    }
+
+	  closedir (dirp);
+	}
+
+      buffer_grow_str0 (&buffer, "</osdata>\n");
+      buf = buffer_finish (&buffer);
+      len_avail = strlen (buf);
+    }
+
+  if (offset >= len_avail)
+    {
+      /* Done.  Get rid of the buffer.  */
+      buffer_free (&buffer);
+      buf = NULL;
+      len_avail = 0;
+      return 0;
+    }
+
+  if (len > len_avail - offset)
+    len = len_avail - offset;
+  memcpy (readbuf, buf + offset, len);
+
+  return len;
+}
+
+/* Returns the socket state STATE in textual form.  */
+
+static const char *
+format_socket_state (unsigned char state)
+{
+  /* Copied from include/net/tcp_states.h in the Linux kernel sources.  */
+  enum {
+    TCP_ESTABLISHED = 1,
+    TCP_SYN_SENT,
+    TCP_SYN_RECV,
+    TCP_FIN_WAIT1,
+    TCP_FIN_WAIT2,
+    TCP_TIME_WAIT,
+    TCP_CLOSE,
+    TCP_CLOSE_WAIT,
+    TCP_LAST_ACK,
+    TCP_LISTEN,
+    TCP_CLOSING
+  };
+
+  switch (state)
+    {
+    case TCP_ESTABLISHED:
+      return "ESTABLISHED";
+    case TCP_SYN_SENT:
+      return "SYN_SENT";
+    case TCP_SYN_RECV:
+      return "SYN_RECV";
+    case TCP_FIN_WAIT1:
+      return "FIN_WAIT1";
+    case TCP_FIN_WAIT2:
+      return "FIN_WAIT2";
+    case TCP_TIME_WAIT:
+      return "TIME_WAIT";
+    case TCP_CLOSE:
+      return "CLOSE";
+    case TCP_CLOSE_WAIT:
+      return "CLOSE_WAIT";
+    case TCP_LAST_ACK:
+      return "LAST_ACK";
+    case TCP_LISTEN:
+      return "LISTEN";
+    case TCP_CLOSING:
+      return "CLOSING";
+    default:
+      return "(unknown)";
+    }
+}
+
+union socket_addr
+  {
+    struct sockaddr sa;
+    struct sockaddr_in sin;
+    struct sockaddr_in6 sin6;
+  };
+
+/* Auxiliary function used by linux_xfer_osdata_isocket.  Formats
+   information for all open internet sockets of type FAMILY on the
+   system into BUFFER.  If TCP is set, only TCP sockets are processed,
+   otherwise only UDP sockets are processed.  */
+
+static void
+print_sockets (unsigned short family, int tcp, struct buffer *buffer)
+{
+  const char *proc_file;
+  FILE *fp;
+
+  if (family == AF_INET)
+    proc_file = tcp ? "/proc/net/tcp" : "/proc/net/udp";
+  else if (family == AF_INET6)
+    proc_file = tcp ? "/proc/net/tcp6" : "/proc/net/udp6";
+  else
+    return;
+
+  fp = gdb_fopen_cloexec (proc_file, "r");
+  if (fp)
+    {
+      char buf[8192];
+
+      do
+	{
+	  if (fgets (buf, sizeof (buf), fp))
+	    {
+	      uid_t uid;
+	      unsigned int local_port, remote_port, state;
+	      char local_address[NI_MAXHOST], remote_address[NI_MAXHOST];
+	      int result;
+
+#if NI_MAXHOST <= 32
+#error "local_address and remote_address buffers too small"
+#endif
+
+	      result = sscanf (buf,
+			       "%*d: %32[0-9A-F]:%X %32[0-9A-F]:%X %X %*X:%*X %*X:%*X %*X %d %*d %*u %*s\n",
+			       local_address, &local_port,
+			       remote_address, &remote_port,
+			       &state,
+			       &uid);
+	      
+	      if (result == 6)
+		{
+		  union socket_addr locaddr, remaddr;
+		  size_t addr_size;
+		  char user[UT_NAMESIZE];
+		  char local_service[NI_MAXSERV], remote_service[NI_MAXSERV];
+
+		  if (family == AF_INET)
+		    {
+		      sscanf (local_address, "%X",
+			      &locaddr.sin.sin_addr.s_addr);
+		      sscanf (remote_address, "%X",
+			      &remaddr.sin.sin_addr.s_addr);
+		      
+		      locaddr.sin.sin_port = htons (local_port);
+		      remaddr.sin.sin_port = htons (remote_port);
+
+		      addr_size = sizeof (struct sockaddr_in);
+		    }
+		  else
+		    {
+		      sscanf (local_address, "%8X%8X%8X%8X",
+			      locaddr.sin6.sin6_addr.s6_addr32,
+			      locaddr.sin6.sin6_addr.s6_addr32 + 1,
+			      locaddr.sin6.sin6_addr.s6_addr32 + 2,
+			      locaddr.sin6.sin6_addr.s6_addr32 + 3);
+		      sscanf (remote_address, "%8X%8X%8X%8X",
+			      remaddr.sin6.sin6_addr.s6_addr32,
+			      remaddr.sin6.sin6_addr.s6_addr32 + 1,
+			      remaddr.sin6.sin6_addr.s6_addr32 + 2,
+			      remaddr.sin6.sin6_addr.s6_addr32 + 3);
+
+		      locaddr.sin6.sin6_port = htons (local_port);
+		      remaddr.sin6.sin6_port = htons (remote_port);
+		      
+		      locaddr.sin6.sin6_flowinfo = 0;
+		      remaddr.sin6.sin6_flowinfo = 0;
+		      locaddr.sin6.sin6_scope_id = 0;
+		      remaddr.sin6.sin6_scope_id = 0;
+
+		      addr_size = sizeof (struct sockaddr_in6);
+		    }
+	      
+		  locaddr.sa.sa_family = remaddr.sa.sa_family = family;
+		      
+		  result = getnameinfo (&locaddr.sa, addr_size,
+					local_address, sizeof (local_address),
+					local_service, sizeof (local_service),
+					NI_NUMERICHOST | NI_NUMERICSERV
+					| (tcp ? 0 : NI_DGRAM));
+		  if (result)
+		    continue;
+		  
+		  result = getnameinfo (&remaddr.sa, addr_size,
+					remote_address,
+					sizeof (remote_address),
+					remote_service,
+					sizeof (remote_service),
+					NI_NUMERICHOST | NI_NUMERICSERV
+					| (tcp ? 0 : NI_DGRAM));
+		  if (result)
+		    continue;
+		  
+		  user_from_uid (user, sizeof (user), uid);
+		  
+		  buffer_xml_printf (
+		      buffer,
+		      "<item>"
+		      "<column name=\"local address\">%s</column>"
+		      "<column name=\"local port\">%s</column>"
+		      "<column name=\"remote address\">%s</column>"
+		      "<column name=\"remote port\">%s</column>"
+		      "<column name=\"state\">%s</column>"
+		      "<column name=\"user\">%s</column>"
+		      "<column name=\"family\">%s</column>" 
+		      "<column name=\"protocol\">%s</column>"
+		      "</item>",
+		      local_address,
+		      local_service,
+		      remote_address,
+		      remote_service,
+		      format_socket_state (state),
+		      user,
+		      (family == AF_INET) ? "INET" : "INET6",
+		      tcp ? "STREAM" : "DGRAM");
+		}
+	    }
+	}
+      while (!feof (fp));
+
+      fclose (fp);
+    }
+}
+
+/* Collect data about internet sockets and write it into READBUF.  */
+
+static LONGEST
+linux_xfer_osdata_isockets (gdb_byte *readbuf,
+			    ULONGEST offset, ULONGEST len)
+{
+  static const char *buf;
+  static LONGEST len_avail = -1;
+  static struct buffer buffer;
+
+  if (offset == 0)
+    {
+      if (len_avail != -1 && len_avail != 0)
+	buffer_free (&buffer);
+      len_avail = 0;
+      buf = NULL;
+      buffer_init (&buffer);
+      buffer_grow_str (&buffer, "<osdata type=\"I sockets\">\n");
+
+      print_sockets (AF_INET, 1, &buffer);
+      print_sockets (AF_INET, 0, &buffer);
+      print_sockets (AF_INET6, 1, &buffer);
+      print_sockets (AF_INET6, 0, &buffer);
+
+      buffer_grow_str0 (&buffer, "</osdata>\n");
+      buf = buffer_finish (&buffer);
+      len_avail = strlen (buf);
+    }
+
+  if (offset >= len_avail)
+    {
+      /* Done.  Get rid of the buffer.  */
+      buffer_free (&buffer);
+      buf = NULL;
+      len_avail = 0;
+      return 0;
+    }
+
+  if (len > len_avail - offset)
+    len = len_avail - offset;
+  memcpy (readbuf, buf + offset, len);
+
+  return len;
+}
+
+/* Converts the time SECONDS into textual form and copies it into a
+   buffer TIME, with at most MAXLEN characters copied.  */
+
+static void
+time_from_time_t (char *time, int maxlen, TIME_T seconds)
+{
+  if (!seconds)
+    time[0] = '\0';
+  else
+    {
+      time_t t = (time_t) seconds;
+      
+      strncpy (time, ctime (&t), maxlen);
+      time[maxlen - 1] = '\0';
+    }
+}
+
+/* Finds the group name for the group GID and copies it into GROUP.
+   At most MAXLEN characters are copied.  */
+
+static void
+group_from_gid (char *group, int maxlen, gid_t gid)
+{
+  struct group *grentry = getgrgid (gid);
+  
+  if (grentry)
+    {
+      strncpy (group, grentry->gr_name, maxlen);
+      /* Ensure that the group name is null-terminated.  */
+      group[maxlen - 1] = '\0';
+    }
+  else
+    group[0] = '\0';
+}
+
+/* Collect data about shared memory recorded in /proc and write it
+   into READBUF.  */
+
+static LONGEST
+linux_xfer_osdata_shm (gdb_byte *readbuf,
+		       ULONGEST offset, ULONGEST len)
+{
+  static const char *buf;
+  static LONGEST len_avail = -1;
+  static struct buffer buffer;
+
+  if (offset == 0)
+    {
+      FILE *fp;
+
+      if (len_avail != -1 && len_avail != 0)
+	buffer_free (&buffer);
+      len_avail = 0;
+      buf = NULL;
+      buffer_init (&buffer);
+      buffer_grow_str (&buffer, "<osdata type=\"shared memory\">\n");
+
+      fp = gdb_fopen_cloexec ("/proc/sysvipc/shm", "r");
+      if (fp)
+	{
+	  char buf[8192];
+
+	  do
+	    {
+	      if (fgets (buf, sizeof (buf), fp))
+		{
+		  key_t key;
+		  uid_t uid, cuid;
+		  gid_t gid, cgid;
+		  PID_T cpid, lpid;
+		  int shmid, size, nattch;
+		  TIME_T atime, dtime, ctime;
+		  unsigned int perms;
+		  int items_read;
+				  
+		  items_read = sscanf (buf,
+				       "%d %d %o %d %lld %lld %d %u %u %u %u %lld %lld %lld",
+				       &key, &shmid, &perms, &size,
+				       &cpid, &lpid,
+				       &nattch,
+				       &uid, &gid, &cuid, &cgid,
+				       &atime, &dtime, &ctime);
+
+		  if (items_read == 14)
+		    {
+		      char user[UT_NAMESIZE], group[UT_NAMESIZE];
+		      char cuser[UT_NAMESIZE], cgroup[UT_NAMESIZE];
+		      char ccmd[32], lcmd[32];
+		      char atime_str[32], dtime_str[32], ctime_str[32];
+		      
+		      user_from_uid (user, sizeof (user), uid);
+		      group_from_gid (group, sizeof (group), gid);
+		      user_from_uid (cuser, sizeof (cuser), cuid);
+		      group_from_gid (cgroup, sizeof (cgroup), cgid);
+		      
+		      command_from_pid (ccmd, sizeof (ccmd), cpid);
+		      command_from_pid (lcmd, sizeof (lcmd), lpid);
+		      
+		      time_from_time_t (atime_str, sizeof (atime_str), atime);
+		      time_from_time_t (dtime_str, sizeof (dtime_str), dtime);
+		      time_from_time_t (ctime_str, sizeof (ctime_str), ctime);
+		      
+		      buffer_xml_printf (
+		          &buffer,
+			  "<item>"
+			  "<column name=\"key\">%d</column>"
+			  "<column name=\"shmid\">%d</column>"
+			  "<column name=\"permissions\">%o</column>"
+			  "<column name=\"size\">%d</column>"
+			  "<column name=\"creator command\">%s</column>"
+			  "<column name=\"last op. command\">%s</column>"
+			  "<column name=\"num attached\">%d</column>"
+			  "<column name=\"user\">%s</column>"
+			  "<column name=\"group\">%s</column>"
+			  "<column name=\"creator user\">%s</column>"
+			  "<column name=\"creator group\">%s</column>"
+			  "<column name=\"last shmat() time\">%s</column>"
+			  "<column name=\"last shmdt() time\">%s</column>"
+			  "<column name=\"last shmctl() time\">%s</column>"
+			  "</item>",
+			  key,
+			  shmid,
+			  perms,
+			  size,
+			  ccmd,
+			  lcmd,
+			  nattch,
+			  user,
+			  group,
+			  cuser,
+			  cgroup,
+			  atime_str,
+			  dtime_str,
+			  ctime_str);
+		    }
+		}
+	    }
+	  while (!feof (fp));
+
+	  fclose (fp);
+	}
+      
+      buffer_grow_str0 (&buffer, "</osdata>\n");
+      buf = buffer_finish (&buffer);
+      len_avail = strlen (buf);
+    }
+
+  if (offset >= len_avail)
+    {
+      /* Done.  Get rid of the buffer.  */
+      buffer_free (&buffer);
+      buf = NULL;
+      len_avail = 0;
+      return 0;
+    }
+
+  if (len > len_avail - offset)
+    len = len_avail - offset;
+  memcpy (readbuf, buf + offset, len);
+
+  return len;
+}
+
+/* Collect data about semaphores recorded in /proc and write it
+   into READBUF.  */
+
+static LONGEST
+linux_xfer_osdata_sem (gdb_byte *readbuf,
+		       ULONGEST offset, ULONGEST len)
+{
+  static const char *buf;
+  static LONGEST len_avail = -1;
+  static struct buffer buffer;
+
+  if (offset == 0)
+    {
+      FILE *fp;
+      
+      if (len_avail != -1 && len_avail != 0)
+	buffer_free (&buffer);
+      len_avail = 0;
+      buf = NULL;
+      buffer_init (&buffer);
+      buffer_grow_str (&buffer, "<osdata type=\"semaphores\">\n");
+
+      fp = gdb_fopen_cloexec ("/proc/sysvipc/sem", "r");
+      if (fp)
+	{
+	  char buf[8192];
+	  
+	  do
+	    {
+	      if (fgets (buf, sizeof (buf), fp))
+		{
+		  key_t key;
+		  uid_t uid, cuid;
+		  gid_t gid, cgid;
+		  unsigned int perms, nsems;
+		  int semid;
+		  TIME_T otime, ctime;
+		  int items_read;
+		  
+		  items_read = sscanf (buf,
+				       "%d %d %o %u %d %d %d %d %lld %lld",
+				       &key, &semid, &perms, &nsems,
+				       &uid, &gid, &cuid, &cgid,
+				       &otime, &ctime);
+		  
+		  if (items_read == 10)
+		    {
+		      char user[UT_NAMESIZE], group[UT_NAMESIZE];
+		      char cuser[UT_NAMESIZE], cgroup[UT_NAMESIZE];
+		      char otime_str[32], ctime_str[32];
+		      
+		      user_from_uid (user, sizeof (user), uid);
+		      group_from_gid (group, sizeof (group), gid);
+		      user_from_uid (cuser, sizeof (cuser), cuid);
+		      group_from_gid (cgroup, sizeof (cgroup), cgid);
+		      
+		      time_from_time_t (otime_str, sizeof (otime_str), otime);
+		      time_from_time_t (ctime_str, sizeof (ctime_str), ctime);
+		      
+		      buffer_xml_printf (
+			  &buffer,
+			  "<item>"
+			  "<column name=\"key\">%d</column>"
+			  "<column name=\"semid\">%d</column>"
+			  "<column name=\"permissions\">%o</column>"
+			  "<column name=\"num semaphores\">%u</column>"
+			  "<column name=\"user\">%s</column>"
+			  "<column name=\"group\">%s</column>"
+			  "<column name=\"creator user\">%s</column>"
+			  "<column name=\"creator group\">%s</column>"
+			  "<column name=\"last semop() time\">%s</column>"
+			  "<column name=\"last semctl() time\">%s</column>"
+			  "</item>",
+			  key,
+			  semid,
+			  perms,
+			  nsems,
+			  user,
+			  group,
+			  cuser,
+			  cgroup,
+			  otime_str,
+			  ctime_str);
+		    }
+		}
+	    }
+	  while (!feof (fp));
+
+	  fclose (fp);
+	}
+
+      buffer_grow_str0 (&buffer, "</osdata>\n");
+      buf = buffer_finish (&buffer);
+      len_avail = strlen (buf);
+    }
+
+  if (offset >= len_avail)
+    {
+      /* Done.  Get rid of the buffer.  */
+      buffer_free (&buffer);
+      buf = NULL;
+      len_avail = 0;
+      return 0;
+    }
+
+  if (len > len_avail - offset)
+    len = len_avail - offset;
+  memcpy (readbuf, buf + offset, len);
+
+  return len;
+}
+
+/* Collect data about message queues recorded in /proc and write it
+   into READBUF.  */
+
+static LONGEST
+linux_xfer_osdata_msg (gdb_byte *readbuf,
+		       ULONGEST offset, ULONGEST len)
+{
+  static const char *buf;
+  static LONGEST len_avail = -1;
+  static struct buffer buffer;
+
+  if (offset == 0)
+    {
+      FILE *fp;
+      
+      if (len_avail != -1 && len_avail != 0)
+	buffer_free (&buffer);
+      len_avail = 0;
+      buf = NULL;
+      buffer_init (&buffer);
+      buffer_grow_str (&buffer, "<osdata type=\"message queues\">\n");
+      
+      fp = gdb_fopen_cloexec ("/proc/sysvipc/msg", "r");
+      if (fp)
+	{
+	  char buf[8192];
+	  
+	  do
+	    {
+	      if (fgets (buf, sizeof (buf), fp))
+		{
+		  key_t key;
+		  PID_T lspid, lrpid;
+		  uid_t uid, cuid;
+		  gid_t gid, cgid;
+		  unsigned int perms, cbytes, qnum;
+		  int msqid;
+		  TIME_T stime, rtime, ctime;
+		  int items_read;
+		  
+		  items_read = sscanf (buf,
+				       "%d %d %o %u %u %lld %lld %d %d %d %d %lld %lld %lld",
+				       &key, &msqid, &perms, &cbytes, &qnum,
+				       &lspid, &lrpid, &uid, &gid, &cuid, &cgid,
+				       &stime, &rtime, &ctime);
+		  
+		  if (items_read == 14)
+		    {
+		      char user[UT_NAMESIZE], group[UT_NAMESIZE];
+		      char cuser[UT_NAMESIZE], cgroup[UT_NAMESIZE];
+		      char lscmd[32], lrcmd[32];
+		      char stime_str[32], rtime_str[32], ctime_str[32];
+		      
+		      user_from_uid (user, sizeof (user), uid);
+		      group_from_gid (group, sizeof (group), gid);
+		      user_from_uid (cuser, sizeof (cuser), cuid);
+		      group_from_gid (cgroup, sizeof (cgroup), cgid);
+		      
+		      command_from_pid (lscmd, sizeof (lscmd), lspid);
+		      command_from_pid (lrcmd, sizeof (lrcmd), lrpid);
+		      
+		      time_from_time_t (stime_str, sizeof (stime_str), stime);
+		      time_from_time_t (rtime_str, sizeof (rtime_str), rtime);
+		      time_from_time_t (ctime_str, sizeof (ctime_str), ctime);
+		      
+		      buffer_xml_printf (
+			  &buffer,
+			  "<item>"
+			  "<column name=\"key\">%d</column>"
+			  "<column name=\"msqid\">%d</column>"
+			  "<column name=\"permissions\">%o</column>"
+			  "<column name=\"num used bytes\">%u</column>"
+			  "<column name=\"num messages\">%u</column>"
+			  "<column name=\"last msgsnd() command\">%s</column>"
+			  "<column name=\"last msgrcv() command\">%s</column>"
+			  "<column name=\"user\">%s</column>"
+			  "<column name=\"group\">%s</column>"
+			  "<column name=\"creator user\">%s</column>"
+			  "<column name=\"creator group\">%s</column>"
+			  "<column name=\"last msgsnd() time\">%s</column>"
+			  "<column name=\"last msgrcv() time\">%s</column>"
+			  "<column name=\"last msgctl() time\">%s</column>"
+			  "</item>",
+			  key,
+			  msqid,
+			  perms,
+			  cbytes,
+			  qnum,
+			  lscmd,
+			  lrcmd,
+			  user,
+			  group,
+			  cuser,
+			  cgroup,
+			  stime_str,
+			  rtime_str,
+			  ctime_str);
+		    }
+		}
+	    }
+	  while (!feof (fp));
+
+	  fclose (fp);
+	}
+
+      buffer_grow_str0 (&buffer, "</osdata>\n");
+      buf = buffer_finish (&buffer);
+      len_avail = strlen (buf);
+    }
+
+  if (offset >= len_avail)
+    {
+      /* Done.  Get rid of the buffer.  */
+      buffer_free (&buffer);
+      buf = NULL;
+      len_avail = 0;
+      return 0;
+    }
+
+  if (len > len_avail - offset)
+    len = len_avail - offset;
+  memcpy (readbuf, buf + offset, len);
+
+  return len;
+}
+
+/* Collect data about loaded kernel modules and write it into
+   READBUF.  */
+
+static LONGEST
+linux_xfer_osdata_modules (gdb_byte *readbuf,
+			   ULONGEST offset, ULONGEST len)
+{
+  static const char *buf;
+  static LONGEST len_avail = -1;
+  static struct buffer buffer;
+
+  if (offset == 0)
+    {
+      FILE *fp;
+
+      if (len_avail != -1 && len_avail != 0)
+	buffer_free (&buffer);
+      len_avail = 0;
+      buf = NULL;
+      buffer_init (&buffer);
+      buffer_grow_str (&buffer, "<osdata type=\"modules\">\n");
+
+      fp = gdb_fopen_cloexec ("/proc/modules", "r");
+      if (fp)
+	{
+	  char buf[8192];
+	  
+	  do
+	    {
+	      if (fgets (buf, sizeof (buf), fp))
+		{
+		  char *name, *dependencies, *status, *tmp;
+		  unsigned int size;
+		  unsigned long long address;
+		  int uses;
+
+		  name = strtok (buf, " ");
+		  if (name == NULL)
+		    continue;
+
+		  tmp = strtok (NULL, " ");
+		  if (tmp == NULL)
+		    continue;
+		  if (sscanf (tmp, "%u", &size) != 1)
+		    continue;
+
+		  tmp = strtok (NULL, " ");
+		  if (tmp == NULL)
+		    continue;
+		  if (sscanf (tmp, "%d", &uses) != 1)
+		    continue;
+
+		  dependencies = strtok (NULL, " ");
+		  if (dependencies == NULL)
+		    continue;
+
+		  status = strtok (NULL, " ");
+		  if (status == NULL)
+		    continue;
+
+		  tmp = strtok (NULL, "\n");
+		  if (tmp == NULL)
+		    continue;
+		  if (sscanf (tmp, "%llx", &address) != 1)
+		    continue;
+
+		  buffer_xml_printf (
+			&buffer,
+			"<item>"
+			"<column name=\"name\">%s</column>"
+			"<column name=\"size\">%u</column>"
+			"<column name=\"num uses\">%d</column>"
+			"<column name=\"dependencies\">%s</column>"
+			"<column name=\"status\">%s</column>"
+			"<column name=\"address\">%llx</column>"
+			"</item>",
+			name,
+			size,
+			uses,
+			dependencies,
+			status,
+			address);
+		}
+	    }
+	  while (!feof (fp));
+
+	  fclose (fp);
+	}
+
+      buffer_grow_str0 (&buffer, "</osdata>\n");
+      buf = buffer_finish (&buffer);
+      len_avail = strlen (buf);
+    }
+
+  if (offset >= len_avail)
+    {
+      /* Done.  Get rid of the buffer.  */
+      buffer_free (&buffer);
+      buf = NULL;
+      len_avail = 0;
+      return 0;
+    }
+
+  if (len > len_avail - offset)
+    len = len_avail - offset;
+  memcpy (readbuf, buf + offset, len);
+
+  return len;
+}
+
+struct osdata_type {
+  char *type;
+  char *title;
+  char *description;
+  LONGEST (*getter) (gdb_byte *readbuf, ULONGEST offset, ULONGEST len);
+} osdata_table[] = {
+  { "processes", "Processes", "Listing of all processes",
+    linux_xfer_osdata_processes },
+  { "procgroups", "Process groups", "Listing of all process groups",
+    linux_xfer_osdata_processgroups },
+  { "threads", "Threads", "Listing of all threads",
+    linux_xfer_osdata_threads },
+  { "files", "File descriptors", "Listing of all file descriptors",
+    linux_xfer_osdata_fds },
+  { "sockets", "Sockets", "Listing of all internet-domain sockets",
+    linux_xfer_osdata_isockets },
+  { "shm", "Shared-memory regions", "Listing of all shared-memory regions",
+    linux_xfer_osdata_shm },
+  { "semaphores", "Semaphores", "Listing of all semaphores",
+    linux_xfer_osdata_sem },
+  { "msg", "Message queues", "Listing of all message queues",
+    linux_xfer_osdata_msg },
+  { "modules", "Kernel modules", "Listing of all loaded kernel modules",
+    linux_xfer_osdata_modules },
+  { NULL, NULL, NULL }
+};
+
+LONGEST
+linux_common_xfer_osdata (const char *annex, gdb_byte *readbuf,
+			  ULONGEST offset, ULONGEST len)
+{
+  if (!annex || *annex == '\0')
+    {
+      static const char *buf;
+      static LONGEST len_avail = -1;
+      static struct buffer buffer;
+
+      if (offset == 0)
+	{
+	  int i;
+
+	  if (len_avail != -1 && len_avail != 0)
+	    buffer_free (&buffer);
+	  len_avail = 0;
+	  buf = NULL;
+	  buffer_init (&buffer);
+	  buffer_grow_str (&buffer, "<osdata type=\"types\">\n");
+
+	  for (i = 0; osdata_table[i].type; ++i)
+	    buffer_xml_printf (
+			       &buffer,
+			       "<item>"
+			       "<column name=\"Type\">%s</column>"
+			       "<column name=\"Description\">%s</column>"
+			       "<column name=\"Title\">%s</column>"
+			       "</item>",
+			       osdata_table[i].type,
+			       osdata_table[i].description,
+			       osdata_table[i].title);
+
+	  buffer_grow_str0 (&buffer, "</osdata>\n");
+	  buf = buffer_finish (&buffer);
+	  len_avail = strlen (buf);
+	}
+
+      if (offset >= len_avail)
+	{
+	  /* Done.  Get rid of the buffer.  */
+	  buffer_free (&buffer);
+	  buf = NULL;
+	  len_avail = 0;
+	  return 0;
+	}
+
+      if (len > len_avail - offset)
+	len = len_avail - offset;
+      memcpy (readbuf, buf + offset, len);
+
+      return len;
+    }
+  else
+    {
+      int i;
+
+      for (i = 0; osdata_table[i].type; ++i)
+	{
+	  if (strcmp (annex, osdata_table[i].type) == 0)
+	    {
+	      gdb_assert (readbuf);
+	      
+	      return (osdata_table[i].getter) (readbuf, offset, len);
+	    }
+	}
+
+      return 0;
+    }
+}
+
diff --git a/gdb/nat/linux-osdata.h b/gdb/nat/linux-osdata.h
new file mode 100644
index 0000000..e9d4f3c
--- /dev/null
+++ b/gdb/nat/linux-osdata.h
@@ -0,0 +1,29 @@
+/* Linux-specific functions to retrieve OS data.
+   
+   Copyright (C) 2009-2014 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 COMMON_LINUX_OSDATA_H
+#define COMMON_LINUX_OSDATA_H
+
+#include "ptid.h"
+
+extern int linux_common_core_of_thread (ptid_t ptid);
+extern LONGEST linux_common_xfer_osdata (const char *annex, gdb_byte *readbuf,
+					 ULONGEST offset, ULONGEST len);
+
+#endif
diff --git a/gdb/nat/linux-procfs.c b/gdb/nat/linux-procfs.c
new file mode 100644
index 0000000..1443a88
--- /dev/null
+++ b/gdb/nat/linux-procfs.c
@@ -0,0 +1,121 @@
+/* Linux-specific PROCFS manipulation routines.
+   Copyright (C) 2009-2014 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/>.  */
+
+#ifdef GDBSERVER
+#include "server.h"
+#else
+#include "defs.h"
+#include <string.h>
+#endif
+
+#include "linux-procfs.h"
+#include "filestuff.h"
+
+/* Return the TGID of LWPID from /proc/pid/status.  Returns -1 if not
+   found.  */
+
+static int
+linux_proc_get_int (pid_t lwpid, const char *field)
+{
+  size_t field_len = strlen (field);
+  FILE *status_file;
+  char buf[100];
+  int retval = -1;
+
+  snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid);
+  status_file = gdb_fopen_cloexec (buf, "r");
+  if (status_file == NULL)
+    {
+      warning (_("unable to open /proc file '%s'"), buf);
+      return -1;
+    }
+
+  while (fgets (buf, sizeof (buf), status_file))
+    if (strncmp (buf, field, field_len) == 0 && buf[field_len] == ':')
+      {
+	retval = strtol (&buf[field_len + 1], NULL, 10);
+	break;
+      }
+
+  fclose (status_file);
+  return retval;
+}
+
+/* Return the TGID of LWPID from /proc/pid/status.  Returns -1 if not
+   found.  */
+
+int
+linux_proc_get_tgid (pid_t lwpid)
+{
+  return linux_proc_get_int (lwpid, "Tgid");
+}
+
+/* See linux-procfs.h.  */
+
+pid_t
+linux_proc_get_tracerpid (pid_t lwpid)
+{
+  return linux_proc_get_int (lwpid, "TracerPid");
+}
+
+/* Return non-zero if 'State' of /proc/PID/status contains STATE.  */
+
+static int
+linux_proc_pid_has_state (pid_t pid, const char *state)
+{
+  char buffer[100];
+  FILE *procfile;
+  int retval;
+  int have_state;
+
+  xsnprintf (buffer, sizeof (buffer), "/proc/%d/status", (int) pid);
+  procfile = gdb_fopen_cloexec (buffer, "r");
+  if (procfile == NULL)
+    {
+      warning (_("unable to open /proc file '%s'"), buffer);
+      return 0;
+    }
+
+  have_state = 0;
+  while (fgets (buffer, sizeof (buffer), procfile) != NULL)
+    if (strncmp (buffer, "State:", 6) == 0)
+      {
+	have_state = 1;
+	break;
+      }
+  retval = (have_state && strstr (buffer, state) != NULL);
+  fclose (procfile);
+  return retval;
+}
+
+/* Detect `T (stopped)' in `/proc/PID/status'.
+   Other states including `T (tracing stop)' are reported as false.  */
+
+int
+linux_proc_pid_is_stopped (pid_t pid)
+{
+  return linux_proc_pid_has_state (pid, "T (stopped)");
+}
+
+/* See linux-procfs.h declaration.  */
+
+int
+linux_proc_pid_is_zombie (pid_t pid)
+{
+  return linux_proc_pid_has_state (pid, "Z (zombie)");
+}
diff --git a/gdb/nat/linux-procfs.h b/gdb/nat/linux-procfs.h
new file mode 100644
index 0000000..d13fff7
--- /dev/null
+++ b/gdb/nat/linux-procfs.h
@@ -0,0 +1,43 @@
+/* Linux-specific PROCFS manipulation routines.
+   Copyright (C) 2011-2014 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 COMMON_LINUX_PROCFS_H
+#define COMMON_LINUX_PROCFS_H
+
+#include <unistd.h>
+
+/* Return the TGID of LWPID from /proc/pid/status.  Returns -1 if not
+   found.  */
+
+extern int linux_proc_get_tgid (pid_t lwpid);
+
+/* Return the TracerPid of LWPID from /proc/pid/status.  Returns -1 if not
+   found.  */
+
+extern pid_t linux_proc_get_tracerpid (pid_t lwpid);
+
+/* Detect `T (stopped)' in `/proc/PID/status'.
+   Other states including `T (tracing stop)' are reported as false.  */
+
+extern int linux_proc_pid_is_stopped (pid_t pid);
+
+/* Return non-zero if PID is a zombie.  */
+
+extern int linux_proc_pid_is_zombie (pid_t pid);
+
+#endif /* COMMON_LINUX_PROCFS_H */
diff --git a/gdb/nat/linux-ptrace.c b/gdb/nat/linux-ptrace.c
new file mode 100644
index 0000000..3ad2113
--- /dev/null
+++ b/gdb/nat/linux-ptrace.c
@@ -0,0 +1,553 @@
+/* Linux-specific ptrace manipulation routines.
+   Copyright (C) 2012-2014 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/>.  */
+
+#ifdef GDBSERVER
+#include "server.h"
+#else
+#include "defs.h"
+#include <string.h>
+#endif
+
+#include "linux-ptrace.h"
+#include "linux-procfs.h"
+#include "linux-waitpid.h"
+#include "buffer.h"
+#include "gdb_assert.h"
+#include "gdb_wait.h"
+
+#include <stdint.h>
+
+/* Stores the currently supported ptrace options.  A value of
+   -1 means we did not check for features yet.  A value of 0 means
+   there are no supported features.  */
+static int current_ptrace_options = -1;
+
+/* Find all possible reasons we could fail to attach PID and append
+   these as strings to the already initialized BUFFER.  '\0'
+   termination of BUFFER must be done by the caller.  */
+
+void
+linux_ptrace_attach_fail_reason (pid_t pid, struct buffer *buffer)
+{
+  pid_t tracerpid;
+
+  tracerpid = linux_proc_get_tracerpid (pid);
+  if (tracerpid > 0)
+    buffer_xml_printf (buffer, _("process %d is already traced "
+				 "by process %d"),
+		       (int) pid, (int) tracerpid);
+
+  if (linux_proc_pid_is_zombie (pid))
+    buffer_xml_printf (buffer, _("process %d is a zombie "
+				 "- the process has already terminated"),
+		       (int) pid);
+}
+
+#if defined __i386__ || defined __x86_64__
+
+/* Address of the 'ret' instruction in asm code block below.  */
+extern void (linux_ptrace_test_ret_to_nx_instr) (void);
+
+#include <sys/reg.h>
+#include <sys/mman.h>
+#include <signal.h>
+
+#endif /* defined __i386__ || defined __x86_64__ */
+
+/* Test broken off-trunk Linux kernel patchset for NX support on i386.  It was
+   removed in Fedora kernel 88fa1f0332d188795ed73d7ac2b1564e11a0b4cd.
+
+   Test also x86_64 arch for PaX support.  */
+
+static void
+linux_ptrace_test_ret_to_nx (void)
+{
+#if defined __i386__ || defined __x86_64__
+  pid_t child, got_pid;
+  gdb_byte *return_address, *pc;
+  long l;
+  int status, kill_status;
+
+  return_address = mmap (NULL, 2, PROT_READ | PROT_WRITE,
+			 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  if (return_address == MAP_FAILED)
+    {
+      warning (_("linux_ptrace_test_ret_to_nx: Cannot mmap: %s"),
+	       strerror (errno));
+      return;
+    }
+
+  /* Put there 'int3'.  */
+  *return_address = 0xcc;
+
+  child = fork ();
+  switch (child)
+    {
+    case -1:
+      warning (_("linux_ptrace_test_ret_to_nx: Cannot fork: %s"),
+	       strerror (errno));
+      return;
+
+    case 0:
+      l = ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) NULL,
+		  (PTRACE_TYPE_ARG4) NULL);
+      if (l != 0)
+	warning (_("linux_ptrace_test_ret_to_nx: Cannot PTRACE_TRACEME: %s"),
+		 strerror (errno));
+      else
+	{
+#if defined __i386__
+	  asm volatile ("pushl %0;"
+			".globl linux_ptrace_test_ret_to_nx_instr;"
+			"linux_ptrace_test_ret_to_nx_instr:"
+			"ret"
+			: : "r" (return_address) : "%esp", "memory");
+#elif defined __x86_64__
+	  asm volatile ("pushq %0;"
+			".globl linux_ptrace_test_ret_to_nx_instr;"
+			"linux_ptrace_test_ret_to_nx_instr:"
+			"ret"
+			: : "r" ((uint64_t) (uintptr_t) return_address)
+			: "%rsp", "memory");
+#else
+# error "!__i386__ && !__x86_64__"
+#endif
+	  gdb_assert_not_reached ("asm block did not terminate");
+	}
+
+      _exit (1);
+    }
+
+  errno = 0;
+  got_pid = waitpid (child, &status, 0);
+  if (got_pid != child)
+    {
+      warning (_("linux_ptrace_test_ret_to_nx: waitpid returned %ld: %s"),
+	       (long) got_pid, strerror (errno));
+      return;
+    }
+
+  if (WIFSIGNALED (status))
+    {
+      if (WTERMSIG (status) != SIGKILL)
+	warning (_("linux_ptrace_test_ret_to_nx: WTERMSIG %d is not SIGKILL!"),
+		 (int) WTERMSIG (status));
+      else
+	warning (_("Cannot call inferior functions, Linux kernel PaX "
+		   "protection forbids return to non-executable pages!"));
+      return;
+    }
+
+  if (!WIFSTOPPED (status))
+    {
+      warning (_("linux_ptrace_test_ret_to_nx: status %d is not WIFSTOPPED!"),
+	       status);
+      return;
+    }
+
+  /* We may get SIGSEGV due to missing PROT_EXEC of the return_address.  */
+  if (WSTOPSIG (status) != SIGTRAP && WSTOPSIG (status) != SIGSEGV)
+    {
+      warning (_("linux_ptrace_test_ret_to_nx: "
+		 "WSTOPSIG %d is neither SIGTRAP nor SIGSEGV!"),
+	       (int) WSTOPSIG (status));
+      return;
+    }
+
+  errno = 0;
+#if defined __i386__
+  l = ptrace (PTRACE_PEEKUSER, child, (PTRACE_TYPE_ARG3) (uintptr_t) (EIP * 4),
+	      (PTRACE_TYPE_ARG4) NULL);
+#elif defined __x86_64__
+  l = ptrace (PTRACE_PEEKUSER, child, (PTRACE_TYPE_ARG3) (uintptr_t) (RIP * 8),
+	      (PTRACE_TYPE_ARG4) NULL);
+#else
+# error "!__i386__ && !__x86_64__"
+#endif
+  if (errno != 0)
+    {
+      warning (_("linux_ptrace_test_ret_to_nx: Cannot PTRACE_PEEKUSER: %s"),
+	       strerror (errno));
+      return;
+    }
+  pc = (void *) (uintptr_t) l;
+
+  kill (child, SIGKILL);
+  ptrace (PTRACE_KILL, child, (PTRACE_TYPE_ARG3) NULL,
+	  (PTRACE_TYPE_ARG4) NULL);
+
+  errno = 0;
+  got_pid = waitpid (child, &kill_status, 0);
+  if (got_pid != child)
+    {
+      warning (_("linux_ptrace_test_ret_to_nx: "
+		 "PTRACE_KILL waitpid returned %ld: %s"),
+	       (long) got_pid, strerror (errno));
+      return;
+    }
+  if (!WIFSIGNALED (kill_status))
+    {
+      warning (_("linux_ptrace_test_ret_to_nx: "
+		 "PTRACE_KILL status %d is not WIFSIGNALED!"),
+	       status);
+      return;
+    }
+
+  /* + 1 is there as x86* stops after the 'int3' instruction.  */
+  if (WSTOPSIG (status) == SIGTRAP && pc == return_address + 1)
+    {
+      /* PASS */
+      return;
+    }
+
+  /* We may get SIGSEGV due to missing PROT_EXEC of the RETURN_ADDRESS page.  */
+  if (WSTOPSIG (status) == SIGSEGV && pc == return_address)
+    {
+      /* PASS */
+      return;
+    }
+
+  if ((void (*) (void)) pc != &linux_ptrace_test_ret_to_nx_instr)
+    warning (_("linux_ptrace_test_ret_to_nx: PC %p is neither near return "
+	       "address %p nor is the return instruction %p!"),
+	     pc, return_address, &linux_ptrace_test_ret_to_nx_instr);
+  else
+    warning (_("Cannot call inferior functions on this system - "
+	       "Linux kernel with broken i386 NX (non-executable pages) "
+	       "support detected!"));
+#endif /* defined __i386__ || defined __x86_64__ */
+}
+
+/* Helper function to fork a process and make the child process call
+   the function FUNCTION, passing CHILD_STACK as parameter.
+
+   For MMU-less targets, clone is used instead of fork, and
+   CHILD_STACK is used as stack space for the cloned child.  If NULL,
+   stack space is allocated via malloc (and subsequently passed to
+   FUNCTION).  For MMU targets, CHILD_STACK is ignored.  */
+
+static int
+linux_fork_to_function (gdb_byte *child_stack, void (*function) (gdb_byte *))
+{
+  int child_pid;
+
+  /* Sanity check the function pointer.  */
+  gdb_assert (function != NULL);
+
+#if defined(__UCLIBC__) && defined(HAS_NOMMU)
+#define STACK_SIZE 4096
+
+    if (child_stack == NULL)
+      child_stack = xmalloc (STACK_SIZE * 4);
+
+    /* Use CLONE_VM instead of fork, to support uClinux (no MMU).  */
+#ifdef __ia64__
+      child_pid = __clone2 (function, child_stack, STACK_SIZE,
+			    CLONE_VM | SIGCHLD, child_stack + STACK_SIZE * 2);
+#else /* !__ia64__ */
+      child_pid = clone (function, child_stack + STACK_SIZE,
+			 CLONE_VM | SIGCHLD, child_stack + STACK_SIZE * 2);
+#endif /* !__ia64__ */
+#else /* !defined(__UCLIBC) && defined(HAS_NOMMU) */
+  child_pid = fork ();
+
+  if (child_pid == 0)
+    function (NULL);
+#endif /* defined(__UCLIBC) && defined(HAS_NOMMU) */
+
+  if (child_pid == -1)
+    perror_with_name (("fork"));
+
+  return child_pid;
+}
+
+/* A helper function for linux_check_ptrace_features, called after
+   the child forks a grandchild.  */
+
+static void
+linux_grandchild_function (gdb_byte *child_stack)
+{
+  /* Free any allocated stack.  */
+  xfree (child_stack);
+
+  /* This code is only reacheable by the grandchild (child's child)
+     process.  */
+  _exit (0);
+}
+
+/* A helper function for linux_check_ptrace_features, called after
+   the parent process forks a child.  The child allows itself to
+   be traced by its parent.  */
+
+static void
+linux_child_function (gdb_byte *child_stack)
+{
+  ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
+  kill (getpid (), SIGSTOP);
+
+  /* Fork a grandchild.  */
+  linux_fork_to_function (child_stack, linux_grandchild_function);
+
+  /* This code is only reacheable by the child (grandchild's parent)
+     process.  */
+  _exit (0);
+}
+
+static void linux_test_for_tracesysgood (int child_pid);
+static void linux_test_for_tracefork (int child_pid);
+
+/* Determine ptrace features available on this target.  */
+
+static void
+linux_check_ptrace_features (void)
+{
+  int child_pid, ret, status;
+
+  /* Initialize the options.  */
+  current_ptrace_options = 0;
+
+  /* Fork a child so we can do some testing.  The child will call
+     linux_child_function and will get traced.  The child will
+     eventually fork a grandchild so we can test fork event
+     reporting.  */
+  child_pid = linux_fork_to_function (NULL, linux_child_function);
+
+  ret = my_waitpid (child_pid, &status, 0);
+  if (ret == -1)
+    perror_with_name (("waitpid"));
+  else if (ret != child_pid)
+    error (_("linux_check_ptrace_features: waitpid: unexpected result %d."),
+	   ret);
+  if (! WIFSTOPPED (status))
+    error (_("linux_check_ptrace_features: waitpid: unexpected status %d."),
+	   status);
+
+  linux_test_for_tracesysgood (child_pid);
+
+  linux_test_for_tracefork (child_pid);
+
+  /* Clean things up and kill any pending children.  */
+  do
+    {
+      ret = ptrace (PTRACE_KILL, child_pid, (PTRACE_TYPE_ARG3) 0,
+		    (PTRACE_TYPE_ARG4) 0);
+      if (ret != 0)
+	warning (_("linux_check_ptrace_features: failed to kill child"));
+      my_waitpid (child_pid, &status, 0);
+    }
+  while (WIFSTOPPED (status));
+}
+
+/* Determine if PTRACE_O_TRACESYSGOOD can be used to catch
+   syscalls.  */
+
+static void
+linux_test_for_tracesysgood (int child_pid)
+{
+#ifdef GDBSERVER
+  /* gdbserver does not support PTRACE_O_TRACESYSGOOD.  */
+#else
+  int ret;
+
+  ret = ptrace (PTRACE_SETOPTIONS, child_pid, (PTRACE_TYPE_ARG3) 0,
+		(PTRACE_TYPE_ARG4) PTRACE_O_TRACESYSGOOD);
+  if (ret == 0)
+    current_ptrace_options |= PTRACE_O_TRACESYSGOOD;
+#endif
+}
+
+/* Determine if PTRACE_O_TRACEFORK can be used to follow fork
+   events.  */
+
+static void
+linux_test_for_tracefork (int child_pid)
+{
+  int ret, status;
+  long second_pid;
+
+  /* First, set the PTRACE_O_TRACEFORK option.  If this fails, we
+     know for sure that it is not supported.  */
+  ret = ptrace (PTRACE_SETOPTIONS, child_pid, (PTRACE_TYPE_ARG3) 0,
+		(PTRACE_TYPE_ARG4) PTRACE_O_TRACEFORK);
+
+  if (ret != 0)
+    return;
+
+#ifdef GDBSERVER
+  /* gdbserver does not support PTRACE_O_TRACEVFORKDONE yet.  */
+#else
+  /* Check if the target supports PTRACE_O_TRACEVFORKDONE.  */
+  ret = ptrace (PTRACE_SETOPTIONS, child_pid, (PTRACE_TYPE_ARG3) 0,
+		(PTRACE_TYPE_ARG4) (PTRACE_O_TRACEFORK
+				    | PTRACE_O_TRACEVFORKDONE));
+  if (ret == 0)
+    current_ptrace_options |= PTRACE_O_TRACEVFORKDONE;
+#endif
+
+  /* Setting PTRACE_O_TRACEFORK did not cause an error, however we
+     don't know for sure that the feature is available; old
+     versions of PTRACE_SETOPTIONS ignored unknown options.
+     Therefore, we attach to the child process, use PTRACE_SETOPTIONS
+     to enable fork tracing, and let it fork.  If the process exits,
+     we assume that we can't use PTRACE_O_TRACEFORK; if we get the
+     fork notification, and we can extract the new child's PID, then
+     we assume that we can.
+
+     We do not explicitly check for vfork tracing here.  It is
+     assumed that vfork tracing is available whenever fork tracing
+     is available.  */
+  ret = ptrace (PTRACE_CONT, child_pid, (PTRACE_TYPE_ARG3) 0,
+		(PTRACE_TYPE_ARG4) 0);
+  if (ret != 0)
+    warning (_("linux_test_for_tracefork: failed to resume child"));
+
+  ret = my_waitpid (child_pid, &status, 0);
+
+  /* Check if we received a fork event notification.  */
+  if (ret == child_pid && WIFSTOPPED (status)
+      && status >> 16 == PTRACE_EVENT_FORK)
+    {
+      /* We did receive a fork event notification.  Make sure its PID
+	 is reported.  */
+      second_pid = 0;
+      ret = ptrace (PTRACE_GETEVENTMSG, child_pid, (PTRACE_TYPE_ARG3) 0,
+		    (PTRACE_TYPE_ARG4) &second_pid);
+      if (ret == 0 && second_pid != 0)
+	{
+	  int second_status;
+
+	  /* We got the PID from the grandchild, which means fork
+	     tracing is supported.  */
+#ifdef GDBSERVER
+	  /* Do not enable all the options for now since gdbserver does not
+	     properly support them.  This restriction will be lifted when
+	     gdbserver is augmented to support them.  */
+	  current_ptrace_options |= PTRACE_O_TRACECLONE;
+#else
+	  current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK
+	    | PTRACE_O_TRACECLONE | PTRACE_O_TRACEEXEC;
+
+	  /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to
+	     support read-only process state.  */
+#endif
+
+	  /* Do some cleanup and kill the grandchild.  */
+	  my_waitpid (second_pid, &second_status, 0);
+	  ret = ptrace (PTRACE_KILL, second_pid, (PTRACE_TYPE_ARG3) 0,
+			(PTRACE_TYPE_ARG4) 0);
+	  if (ret != 0)
+	    warning (_("linux_test_for_tracefork: "
+		       "failed to kill second child"));
+	  my_waitpid (second_pid, &status, 0);
+	}
+    }
+  else
+    warning (_("linux_test_for_tracefork: unexpected result from waitpid "
+	     "(%d, status 0x%x)"), ret, status);
+}
+
+/* Enable reporting of all currently supported ptrace events.  */
+
+void
+linux_enable_event_reporting (pid_t pid)
+{
+  /* Check if we have initialized the ptrace features for this
+     target.  If not, do it now.  */
+  if (current_ptrace_options == -1)
+    linux_check_ptrace_features ();
+
+  /* Set the options.  */
+  ptrace (PTRACE_SETOPTIONS, pid, (PTRACE_TYPE_ARG3) 0,
+	  (PTRACE_TYPE_ARG4) (uintptr_t) current_ptrace_options);
+}
+
+/* Disable reporting of all currently supported ptrace events.  */
+
+void
+linux_disable_event_reporting (pid_t pid)
+{
+  /* Set the options.  */
+  ptrace (PTRACE_SETOPTIONS, pid, (PTRACE_TYPE_ARG3) 0, 0);
+}
+
+/* Returns non-zero if PTRACE_OPTIONS is contained within
+   CURRENT_PTRACE_OPTIONS, therefore supported.  Returns 0
+   otherwise.  */
+
+static int
+ptrace_supports_feature (int ptrace_options)
+{
+  gdb_assert (current_ptrace_options >= 0);
+
+  return ((current_ptrace_options & ptrace_options) == ptrace_options);
+}
+
+/* Returns non-zero if PTRACE_EVENT_FORK is supported by ptrace,
+   0 otherwise.  Note that if PTRACE_EVENT_FORK is supported so is
+   PTRACE_EVENT_CLONE, PTRACE_EVENT_EXEC and PTRACE_EVENT_VFORK,
+   since they were all added to the kernel at the same time.  */
+
+int
+linux_supports_tracefork (void)
+{
+  return ptrace_supports_feature (PTRACE_O_TRACEFORK);
+}
+
+/* Returns non-zero if PTRACE_EVENT_CLONE is supported by ptrace,
+   0 otherwise.  Note that if PTRACE_EVENT_CLONE is supported so is
+   PTRACE_EVENT_FORK, PTRACE_EVENT_EXEC and PTRACE_EVENT_VFORK,
+   since they were all added to the kernel at the same time.  */
+
+int
+linux_supports_traceclone (void)
+{
+  return ptrace_supports_feature (PTRACE_O_TRACECLONE);
+}
+
+/* Returns non-zero if PTRACE_O_TRACEVFORKDONE is supported by
+   ptrace, 0 otherwise.  */
+
+int
+linux_supports_tracevforkdone (void)
+{
+  return ptrace_supports_feature (PTRACE_O_TRACEVFORKDONE);
+}
+
+/* Returns non-zero if PTRACE_O_TRACESYSGOOD is supported by ptrace,
+   0 otherwise.  */
+
+int
+linux_supports_tracesysgood (void)
+{
+  return ptrace_supports_feature (PTRACE_O_TRACESYSGOOD);
+}
+
+/* Display possible problems on this system.  Display them only once per GDB
+   execution.  */
+
+void
+linux_ptrace_init_warnings (void)
+{
+  static int warned = 0;
+
+  if (warned)
+    return;
+  warned = 1;
+
+  linux_ptrace_test_ret_to_nx ();
+}
diff --git a/gdb/nat/linux-ptrace.h b/gdb/nat/linux-ptrace.h
new file mode 100644
index 0000000..cffb5ce
--- /dev/null
+++ b/gdb/nat/linux-ptrace.h
@@ -0,0 +1,95 @@
+/* Copyright (C) 2011-2014 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 COMMON_LINUX_PTRACE_H
+#define COMMON_LINUX_PTRACE_H
+
+struct buffer;
+
+#include <sys/ptrace.h>
+
+#ifdef __UCLIBC__
+#if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
+/* PTRACE_TEXT_ADDR and friends.  */
+#include <asm/ptrace.h>
+#define HAS_NOMMU
+#endif
+#endif
+
+#if !defined(PTRACE_TYPE_ARG3)
+#define PTRACE_TYPE_ARG3 void *
+#endif
+
+#if !defined(PTRACE_TYPE_ARG4)
+#define PTRACE_TYPE_ARG4 void *
+#endif
+
+#ifndef PTRACE_GETSIGINFO
+# define PTRACE_GETSIGINFO 0x4202
+# define PTRACE_SETSIGINFO 0x4203
+#endif /* PTRACE_GETSIGINF */
+
+/* If the system headers did not provide the constants, hard-code the normal
+   values.  */
+#ifndef PTRACE_EVENT_FORK
+
+#define PTRACE_SETOPTIONS	0x4200
+#define PTRACE_GETEVENTMSG	0x4201
+
+/* options set using PTRACE_SETOPTIONS */
+#define PTRACE_O_TRACESYSGOOD	0x00000001
+#define PTRACE_O_TRACEFORK	0x00000002
+#define PTRACE_O_TRACEVFORK	0x00000004
+#define PTRACE_O_TRACECLONE	0x00000008
+#define PTRACE_O_TRACEEXEC	0x00000010
+#define PTRACE_O_TRACEVFORKDONE	0x00000020
+#define PTRACE_O_TRACEEXIT	0x00000040
+
+/* Wait extended result codes for the above trace options.  */
+#define PTRACE_EVENT_FORK	1
+#define PTRACE_EVENT_VFORK	2
+#define PTRACE_EVENT_CLONE	3
+#define PTRACE_EVENT_EXEC	4
+#define PTRACE_EVENT_VFORK_DONE	5
+#define PTRACE_EVENT_EXIT	6
+
+#endif /* PTRACE_EVENT_FORK */
+
+#if (defined __bfin__ || defined __frv__ || defined __sh__) \
+    && !defined PTRACE_GETFDPIC
+#define PTRACE_GETFDPIC		31
+#define PTRACE_GETFDPIC_EXEC	0
+#define PTRACE_GETFDPIC_INTERP	1
+#endif
+
+/* We can't always assume that this flag is available, but all systems
+   with the ptrace event handlers also have __WALL, so it's safe to use
+   in some contexts.  */
+#ifndef __WALL
+#define __WALL          0x40000000 /* Wait for any child.  */
+#endif
+
+extern void linux_ptrace_attach_fail_reason (pid_t pid, struct buffer *buffer);
+extern void linux_ptrace_init_warnings (void);
+extern void linux_enable_event_reporting (pid_t pid);
+extern void linux_disable_event_reporting (pid_t pid);
+extern int linux_supports_tracefork (void);
+extern int linux_supports_traceclone (void);
+extern int linux_supports_tracevforkdone (void);
+extern int linux_supports_tracesysgood (void);
+
+#endif /* COMMON_LINUX_PTRACE_H */
diff --git a/gdb/nat/linux-waitpid.c b/gdb/nat/linux-waitpid.c
index 4693120..5159f03 100644
--- a/gdb/nat/linux-waitpid.c
+++ b/gdb/nat/linux-waitpid.c
@@ -24,8 +24,8 @@
 #include "signal.h"
 #endif
 
-#include "nat/linux-nat.h"
-#include "nat/linux-waitpid.h"
+#include "linux-nat.h"
+#include "linux-waitpid.h"
 #include "gdb_wait.h"
 
 #include <string.h>
diff --git a/gdb/nat/mips-linux-watch.c b/gdb/nat/mips-linux-watch.c
new file mode 100644
index 0000000..acfc7f4
--- /dev/null
+++ b/gdb/nat/mips-linux-watch.c
@@ -0,0 +1,349 @@
+/* Copyright (C) 2009-2014 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 <sys/ptrace.h>
+#include "mips-linux-watch.h"
+#include "gdb_assert.h"
+
+/* Assuming usable watch registers REGS, return the irw_mask of
+   register N.  */
+
+uint32_t
+mips_linux_watch_get_irw_mask (struct pt_watch_regs *regs, int n)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      return regs->mips32.watch_masks[n] & IRW_MASK;
+    case pt_watch_style_mips64:
+      return regs->mips64.watch_masks[n] & IRW_MASK;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, return the reg_mask of
+   register N.  */
+
+static uint32_t
+get_reg_mask (struct pt_watch_regs *regs, int n)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      return regs->mips32.watch_masks[n] & ~IRW_MASK;
+    case pt_watch_style_mips64:
+      return regs->mips64.watch_masks[n] & ~IRW_MASK;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, return the num_valid.  */
+
+uint32_t
+mips_linux_watch_get_num_valid (struct pt_watch_regs *regs)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      return regs->mips32.num_valid;
+    case pt_watch_style_mips64:
+      return regs->mips64.num_valid;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, return the watchlo of
+   register N.  */
+
+CORE_ADDR
+mips_linux_watch_get_watchlo (struct pt_watch_regs *regs, int n)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      return regs->mips32.watchlo[n];
+    case pt_watch_style_mips64:
+      return regs->mips64.watchlo[n];
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, set watchlo of register N to
+   VALUE.  */
+
+void
+mips_linux_watch_set_watchlo (struct pt_watch_regs *regs, int n,
+			      CORE_ADDR value)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      /*  The cast will never throw away bits as 64 bit addresses can
+	  never be used on a 32 bit kernel.  */
+      regs->mips32.watchlo[n] = (uint32_t) value;
+      break;
+    case pt_watch_style_mips64:
+      regs->mips64.watchlo[n] = value;
+      break;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, return the watchhi of
+   register N.  */
+
+uint32_t
+mips_linux_watch_get_watchhi (struct pt_watch_regs *regs, int n)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      return regs->mips32.watchhi[n];
+    case pt_watch_style_mips64:
+      return regs->mips64.watchhi[n];
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, set watchhi of register N to
+   VALUE.  */
+
+void
+mips_linux_watch_set_watchhi (struct pt_watch_regs *regs, int n,
+			      uint16_t value)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      regs->mips32.watchhi[n] = value;
+      break;
+    case pt_watch_style_mips64:
+      regs->mips64.watchhi[n] = value;
+      break;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Read the watch registers of process LWPID and store it in
+   WATCH_READBACK.  Save true to *WATCH_READBACK_VALID if watch
+   registers are valid.  Return 1 if watch registers are usable.
+   Cached information is used unless FORCE is true.  */
+
+int
+mips_linux_read_watch_registers (long lwpid,
+				 struct pt_watch_regs *watch_readback,
+				 int *watch_readback_valid, int force)
+{
+  if (force || *watch_readback_valid == 0)
+    {
+      if (ptrace (PTRACE_GET_WATCH_REGS, lwpid, watch_readback) == -1)
+	{
+	  *watch_readback_valid = -1;
+	  return 0;
+	}
+      switch (watch_readback->style)
+	{
+	case pt_watch_style_mips32:
+	  if (watch_readback->mips32.num_valid == 0)
+	    {
+	      *watch_readback_valid = -1;
+	      return 0;
+	    }
+	  break;
+	case pt_watch_style_mips64:
+	  if (watch_readback->mips64.num_valid == 0)
+	    {
+	      *watch_readback_valid = -1;
+	      return 0;
+	    }
+	  break;
+	default:
+	  *watch_readback_valid = -1;
+	  return 0;
+	}
+      /* Watch registers appear to be usable.  */
+      *watch_readback_valid = 1;
+    }
+  return (*watch_readback_valid == 1) ? 1 : 0;
+}
+
+/* Convert GDB's TYPE to an IRW mask.  */
+
+uint32_t
+mips_linux_watch_type_to_irw (int type)
+{
+  switch (type)
+    {
+    case hw_write:
+      return W_MASK;
+    case hw_read:
+      return R_MASK;
+    case hw_access:
+      return (W_MASK | R_MASK);
+    default:
+      return 0;
+    }
+}
+
+/* Set any low order bits in MASK that are not set.  */
+
+static CORE_ADDR
+fill_mask (CORE_ADDR mask)
+{
+  CORE_ADDR f = 1;
+
+  while (f && f < mask)
+    {
+      mask |= f;
+      f <<= 1;
+    }
+  return mask;
+}
+
+/* Try to add a single watch to the specified registers REGS.  The
+   address of added watch is ADDR, the length is LEN, and the mask
+   is IRW.  Return 1 on success, 0 on failure.  */
+
+int
+mips_linux_watch_try_one_watch (struct pt_watch_regs *regs,
+				CORE_ADDR addr, int len, uint32_t irw)
+{
+  CORE_ADDR base_addr, last_byte, break_addr, segment_len;
+  CORE_ADDR mask_bits, t_low;
+  uint16_t t_hi;
+  int i, free_watches;
+  struct pt_watch_regs regs_copy;
+
+  if (len <= 0)
+    return 0;
+
+  last_byte = addr + len - 1;
+  mask_bits = fill_mask (addr ^ last_byte) | IRW_MASK;
+  base_addr = addr & ~mask_bits;
+
+  /* Check to see if it is covered by current registers.  */
+  for (i = 0; i < mips_linux_watch_get_num_valid (regs); i++)
+    {
+      t_low = mips_linux_watch_get_watchlo (regs, i);
+      if (t_low != 0 && irw == ((uint32_t) t_low & irw))
+	{
+	  t_hi = mips_linux_watch_get_watchhi (regs, i) | IRW_MASK;
+	  t_low &= ~(CORE_ADDR) t_hi;
+	  if (addr >= t_low && last_byte <= (t_low + t_hi))
+	    return 1;
+	}
+    }
+  /* Try to find an empty register.  */
+  free_watches = 0;
+  for (i = 0; i < mips_linux_watch_get_num_valid (regs); i++)
+    {
+      t_low = mips_linux_watch_get_watchlo (regs, i);
+      if (t_low == 0
+	  && irw == (mips_linux_watch_get_irw_mask (regs, i) & irw))
+	{
+	  if (mask_bits <= (get_reg_mask (regs, i) | IRW_MASK))
+	    {
+	      /* It fits, we'll take it.  */
+	      mips_linux_watch_set_watchlo (regs, i, base_addr | irw);
+	      mips_linux_watch_set_watchhi (regs, i, mask_bits & ~IRW_MASK);
+	      return 1;
+	    }
+	  else
+	    {
+	      /* It doesn't fit, but has the proper IRW capabilities.  */
+	      free_watches++;
+	    }
+	}
+    }
+  if (free_watches > 1)
+    {
+      /* Try to split it across several registers.  */
+      regs_copy = *regs;
+      for (i = 0; i < mips_linux_watch_get_num_valid (&regs_copy); i++)
+	{
+	  t_low = mips_linux_watch_get_watchlo (&regs_copy, i);
+	  t_hi = get_reg_mask (&regs_copy, i) | IRW_MASK;
+	  if (t_low == 0 && irw == (t_hi & irw))
+	    {
+	      t_low = addr & ~(CORE_ADDR) t_hi;
+	      break_addr = t_low + t_hi + 1;
+	      if (break_addr >= addr + len)
+		segment_len = len;
+	      else
+		segment_len = break_addr - addr;
+	      mask_bits = fill_mask (addr ^ (addr + segment_len - 1));
+	      mips_linux_watch_set_watchlo (&regs_copy, i,
+					    (addr & ~mask_bits) | irw);
+	      mips_linux_watch_set_watchhi (&regs_copy, i,
+					    mask_bits & ~IRW_MASK);
+	      if (break_addr >= addr + len)
+		{
+		  *regs = regs_copy;
+		  return 1;
+		}
+	      len = addr + len - break_addr;
+	      addr = break_addr;
+	    }
+	}
+    }
+  /* It didn't fit anywhere, we failed.  */
+  return 0;
+}
+
+/* Fill in the watch registers REGS with the currently cached
+   watches CURRENT_WATCHES.  */
+
+void
+mips_linux_watch_populate_regs (struct mips_watchpoint *current_watches,
+				struct pt_watch_regs *regs)
+{
+  struct mips_watchpoint *w;
+  int i;
+
+  /* Clear them out.  */
+  for (i = 0; i < mips_linux_watch_get_num_valid (regs); i++)
+    {
+      mips_linux_watch_set_watchlo (regs, i, 0);
+      mips_linux_watch_set_watchhi (regs, i, 0);
+    }
+
+  w = current_watches;
+  while (w)
+    {
+      uint32_t irw = mips_linux_watch_type_to_irw (w->type);
+
+      i = mips_linux_watch_try_one_watch (regs, w->addr, w->len, irw);
+      /* They must all fit, because we previously calculated that they
+	 would.  */
+      gdb_assert (i);
+      w = w->next;
+    }
+}
diff --git a/gdb/nat/mips-linux-watch.h b/gdb/nat/mips-linux-watch.h
new file mode 100644
index 0000000..c9f6932
--- /dev/null
+++ b/gdb/nat/mips-linux-watch.h
@@ -0,0 +1,126 @@
+/* Copyright (C) 2009-2014 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 MIPS_LINUX_WATCH_H
+#define MIPS_LINUX_WATCH_H 1
+
+#ifdef GDBSERVER
+#include "server.h"
+#else
+#include "defs.h"
+#endif
+
+#include <asm/ptrace.h>
+#include <stdint.h>
+
+#include "break-common.h"
+
+#define MAX_DEBUG_REGISTER 8
+
+/* If macro PTRACE_GET_WATCH_REGS is not defined, kernel header doesn't
+   have hardware watchpoint-related structures.  Define them below.  */
+
+#ifndef PTRACE_GET_WATCH_REGS
+#  define PTRACE_GET_WATCH_REGS	0xd0
+#  define PTRACE_SET_WATCH_REGS	0xd1
+
+enum pt_watch_style {
+  pt_watch_style_mips32,
+  pt_watch_style_mips64
+};
+
+/* A value of zero in a watchlo indicates that it is available.  */
+
+struct mips32_watch_regs
+{
+  uint32_t watchlo[MAX_DEBUG_REGISTER];
+  /* Lower 16 bits of watchhi.  */
+  uint16_t watchhi[MAX_DEBUG_REGISTER];
+  /* Valid mask and I R W bits.
+   * bit 0 -- 1 if W bit is usable.
+   * bit 1 -- 1 if R bit is usable.
+   * bit 2 -- 1 if I bit is usable.
+   * bits 3 - 11 -- Valid watchhi mask bits.
+   */
+  uint16_t watch_masks[MAX_DEBUG_REGISTER];
+  /* The number of valid watch register pairs.  */
+  uint32_t num_valid;
+  /* There is confusion across gcc versions about structure alignment,
+     so we force 8 byte alignment for these structures so they match
+     the kernel even if it was build with a different gcc version.  */
+} __attribute__ ((aligned (8)));
+
+struct mips64_watch_regs
+{
+  uint64_t watchlo[MAX_DEBUG_REGISTER];
+  uint16_t watchhi[MAX_DEBUG_REGISTER];
+  uint16_t watch_masks[MAX_DEBUG_REGISTER];
+  uint32_t num_valid;
+} __attribute__ ((aligned (8)));
+
+struct pt_watch_regs
+{
+  enum pt_watch_style style;
+  union
+  {
+    struct mips32_watch_regs mips32;
+    struct mips64_watch_regs mips64;
+  };
+};
+
+#endif /* !PTRACE_GET_WATCH_REGS */
+
+#define W_BIT 0
+#define R_BIT 1
+#define I_BIT 2
+
+#define W_MASK (1 << W_BIT)
+#define R_MASK (1 << R_BIT)
+#define I_MASK (1 << I_BIT)
+
+#define IRW_MASK (I_MASK | R_MASK | W_MASK)
+
+/* We keep list of all watchpoints we should install and calculate the
+   watch register values each time the list changes.  This allows for
+   easy sharing of watch registers for more than one watchpoint.  */
+
+struct mips_watchpoint
+{
+  CORE_ADDR addr;
+  int len;
+  int type;
+  struct mips_watchpoint *next;
+};
+
+uint32_t mips_linux_watch_get_num_valid (struct pt_watch_regs *regs);
+uint32_t mips_linux_watch_get_irw_mask (struct pt_watch_regs *regs, int n);
+CORE_ADDR mips_linux_watch_get_watchlo (struct pt_watch_regs *regs, int n);
+void mips_linux_watch_set_watchlo (struct pt_watch_regs *regs, int n,
+				   CORE_ADDR value);
+uint32_t mips_linux_watch_get_watchhi (struct pt_watch_regs *regs, int n);
+void mips_linux_watch_set_watchhi (struct pt_watch_regs *regs, int n,
+				   uint16_t value);
+int mips_linux_watch_try_one_watch (struct pt_watch_regs *regs,
+				    CORE_ADDR addr, int len, uint32_t irw);
+void mips_linux_watch_populate_regs (struct mips_watchpoint *current_watches,
+				     struct pt_watch_regs *regs);
+uint32_t mips_linux_watch_type_to_irw (int type);
+
+int mips_linux_read_watch_registers (long lwpid,
+				     struct pt_watch_regs *watch_readback,
+				     int *watch_readback_valid, int force);
+#endif