X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fgdbserver%2Flinux-x86-low.c;h=f09871ac36fc9fad0451056daa36b547dbe32743;hb=b4570e4b3032f9f4a508dbacd8136f79cf42c249;hp=3dcae007baf43bc0ecb0694dab5468e73a0e730f;hpb=214d508ee1d179d6c9e0e993d68628a0bc477124;p=deliverable%2Fbinutils-gdb.git

diff --git a/gdb/gdbserver/linux-x86-low.c b/gdb/gdbserver/linux-x86-low.c
index 3dcae007ba..f09871ac36 100644
--- a/gdb/gdbserver/linux-x86-low.c
+++ b/gdb/gdbserver/linux-x86-low.c
@@ -1,6 +1,6 @@
 /* GNU/Linux/x86-64 specific low level interface, for the remote server
    for GDB.
-   Copyright (C) 2002, 2004-2012 Free Software Foundation, Inc.
+   Copyright (C) 2002-2017 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -17,30 +17,41 @@
    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 <stddef.h>
+#include "server.h"
 #include <signal.h>
 #include <limits.h>
 #include <inttypes.h>
-#include "server.h"
 #include "linux-low.h"
 #include "i387-fp.h"
-#include "i386-low.h"
-#include "i386-xstate.h"
-#include "elf/common.h"
+#include "x86-low.h"
+#include "x86-xstate.h"
+#include "nat/gdb_ptrace.h"
+
+#ifdef __x86_64__
+#include "nat/amd64-linux-siginfo.h"
+#endif
 
 #include "gdb_proc_service.h"
+/* Don't include elf/common.h if linux/elf.h got included by
+   gdb_proc_service.h.  */
+#ifndef ELFMAG0
+#include "elf/common.h"
+#endif
+
 #include "agent.h"
+#include "tdesc.h"
+#include "tracepoint.h"
+#include "ax.h"
+#include "nat/linux-nat.h"
+#include "nat/x86-linux.h"
+#include "nat/x86-linux-dregs.h"
+#include "linux-x86-tdesc.h"
+
+#ifdef __x86_64__
+static struct target_desc *tdesc_amd64_linux_no_xml;
+#endif
+static struct target_desc *tdesc_i386_linux_no_xml;
 
-/* Defined in auto-generated file i386-linux.c.  */
-void init_registers_i386_linux (void);
-/* Defined in auto-generated file amd64-linux.c.  */
-void init_registers_amd64_linux (void);
-/* Defined in auto-generated file i386-avx-linux.c.  */
-void init_registers_i386_avx_linux (void);
-/* Defined in auto-generated file amd64-avx-linux.c.  */
-void init_registers_amd64_avx_linux (void);
-/* Defined in auto-generated file i386-mmx-linux.c.  */
-void init_registers_i386_mmx_linux (void);
 
 static unsigned char jump_insn[] = { 0xe9, 0, 0, 0, 0 };
 static unsigned char small_jump_insn[] = { 0x66, 0xe9, 0, 0 };
@@ -61,18 +72,9 @@ static const char *xmltarget_amd64_linux_no_xml = "@<target>\
 
 #include <sys/reg.h>
 #include <sys/procfs.h>
-#include <sys/ptrace.h>
+#include "nat/gdb_ptrace.h"
 #include <sys/uio.h>
 
-#ifndef PTRACE_GETREGSET
-#define PTRACE_GETREGSET	0x4204
-#endif
-
-#ifndef PTRACE_SETREGSET
-#define PTRACE_SETREGSET	0x4205
-#endif
-
-
 #ifndef PTRACE_GET_THREAD_AREA
 #define PTRACE_GET_THREAD_AREA 25
 #endif
@@ -95,15 +97,7 @@ static const char *xmltarget_amd64_linux_no_xml = "@<target>\
 
 struct arch_process_info
 {
-  struct i386_debug_reg_state debug_reg_state;
-};
-
-/* Per-thread arch-specific data we want to keep.  */
-
-struct arch_lwp_info
-{
-  /* Non-zero if our copy differs from what's recorded in the thread.  */
-  int debug_registers_changed;
+  struct x86_debug_reg_state debug_reg_state;
 };
 
 #ifdef __x86_64__
@@ -123,6 +117,7 @@ static /*const*/ int i386_regmap[] =
 
 /* So code below doesn't have to care, i386 or amd64.  */
 #define ORIG_EAX ORIG_RAX
+#define REGSIZE 8
 
 static const int x86_64_regmap[] =
 {
@@ -135,11 +130,30 @@ static const int x86_64_regmap[] =
   -1, -1, -1, -1, -1, -1, -1, -1,
   -1, -1, -1, -1, -1, -1, -1, -1,
   -1, -1, -1, -1, -1, -1, -1, -1,
-  -1, -1, -1, -1, -1, -1, -1, -1, -1,
-  ORIG_RAX * 8
+  -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,
+  ORIG_RAX * 8,
+#ifdef HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE
+  21 * 8,  22 * 8,
+#else
+  -1, -1,
+#endif
+  -1, -1, -1, -1,			/* MPX registers BND0 ... BND3.  */
+  -1, -1,				/* MPX registers BNDCFGU, BNDSTATUS.  */
+  -1, -1, -1, -1, -1, -1, -1, -1,       /* xmm16 ... xmm31 (AVX512)  */
+  -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,       /* ymm16 ... ymm31 (AVX512)  */
+  -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,       /* k0 ... k7 (AVX512)  */
+  -1, -1, -1, -1, -1, -1, -1, -1,       /* zmm0 ... zmm31 (AVX512)  */
+  -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,
+  -1					/* pkru  */
 };
 
 #define X86_64_NUM_REGS (sizeof (x86_64_regmap) / sizeof (x86_64_regmap[0]))
+#define X86_64_USER_REGS (GS + 1)
 
 #else /* ! __x86_64__ */
 
@@ -155,16 +169,34 @@ static /*const*/ int i386_regmap[] =
 
 #define I386_NUM_REGS (sizeof (i386_regmap) / sizeof (i386_regmap[0]))
 
+#define REGSIZE 4
+
 #endif
+
+#ifdef __x86_64__
+
+/* Returns true if the current inferior belongs to a x86-64 process,
+   per the tdesc.  */
+
+static int
+is_64bit_tdesc (void)
+{
+  struct regcache *regcache = get_thread_regcache (current_thread, 0);
+
+  return register_size (regcache->tdesc, 0) == 8;
+}
+
+#endif
+
 
 /* Called by libthread_db.  */
 
 ps_err_e
-ps_get_thread_area (const struct ps_prochandle *ph,
+ps_get_thread_area (struct ps_prochandle *ph,
 		    lwpid_t lwpid, int idx, void **base)
 {
 #ifdef __x86_64__
-  int use_64bit = register_size (0) == 8;
+  int use_64bit = is_64bit_tdesc ();
 
   if (use_64bit)
     {
@@ -192,7 +224,8 @@ ps_get_thread_area (const struct ps_prochandle *ph,
 		(void *) (intptr_t) idx, (unsigned long) &desc) < 0)
       return PS_ERR;
 
-    *(int *)base = desc[1];
+    /* Ensure we properly extend the value to 64-bits for x86_64.  */
+    *base = (void *) (uintptr_t) desc[1];
     return PS_OK;
   }
 }
@@ -206,7 +239,7 @@ static int
 x86_get_thread_area (int lwpid, CORE_ADDR *addr)
 {
 #ifdef __x86_64__
-  int use_64bit = register_size (0) == 8;
+  int use_64bit = is_64bit_tdesc ();
 
   if (use_64bit)
     {
@@ -223,7 +256,8 @@ x86_get_thread_area (int lwpid, CORE_ADDR *addr)
 
   {
     struct lwp_info *lwp = find_lwp_pid (pid_to_ptid (lwpid));
-    struct regcache *regcache = get_thread_regcache (get_lwp_thread (lwp), 1);
+    struct thread_info *thr = get_lwp_thread (lwp);
+    struct regcache *regcache = get_thread_regcache (thr, 1);
     unsigned int desc[4];
     ULONGEST gs = 0;
     const int reg_thread_area = 3; /* bits to scale down register value.  */
@@ -234,7 +268,7 @@ x86_get_thread_area (int lwpid, CORE_ADDR *addr)
     idx = gs >> reg_thread_area;
 
     if (ptrace (PTRACE_GET_THREAD_AREA,
-		lwpid_of (lwp),
+		lwpid_of (thr),
 		(void *) (long) idx, (unsigned long) &desc) < 0)
       return -1;
 
@@ -246,14 +280,24 @@ x86_get_thread_area (int lwpid, CORE_ADDR *addr)
 
 
 static int
-i386_cannot_store_register (int regno)
+x86_cannot_store_register (int regno)
 {
+#ifdef __x86_64__
+  if (is_64bit_tdesc ())
+    return 0;
+#endif
+
   return regno >= I386_NUM_REGS;
 }
 
 static int
-i386_cannot_fetch_register (int regno)
+x86_cannot_fetch_register (int regno)
 {
+#ifdef __x86_64__
+  if (is_64bit_tdesc ())
+    return 0;
+#endif
+
   return regno >= I386_NUM_REGS;
 }
 
@@ -263,20 +307,38 @@ x86_fill_gregset (struct regcache *regcache, void *buf)
   int i;
 
 #ifdef __x86_64__
-  if (register_size (0) == 8)
+  if (register_size (regcache->tdesc, 0) == 8)
     {
       for (i = 0; i < X86_64_NUM_REGS; i++)
 	if (x86_64_regmap[i] != -1)
 	  collect_register (regcache, i, ((char *) buf) + x86_64_regmap[i]);
+
+#ifndef HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE
+      {
+        unsigned long base;
+        int lwpid = lwpid_of (current_thread);
+
+        collect_register_by_name (regcache, "fs_base", &base);
+        ptrace (PTRACE_ARCH_PRCTL, lwpid, &base, ARCH_SET_FS);
+
+        collect_register_by_name (regcache, "gs_base", &base);
+        ptrace (PTRACE_ARCH_PRCTL, lwpid, &base, ARCH_SET_GS);
+      }
+#endif
+
       return;
     }
+
+  /* 32-bit inferior registers need to be zero-extended.
+     Callers would read uninitialized memory otherwise.  */
+  memset (buf, 0x00, X86_64_USER_REGS * 8);
 #endif
 
   for (i = 0; i < I386_NUM_REGS; i++)
     collect_register (regcache, i, ((char *) buf) + i386_regmap[i]);
 
   collect_register_by_name (regcache, "orig_eax",
-			    ((char *) buf) + ORIG_EAX * 4);
+			    ((char *) buf) + ORIG_EAX * REGSIZE);
 }
 
 static void
@@ -285,11 +347,24 @@ x86_store_gregset (struct regcache *regcache, const void *buf)
   int i;
 
 #ifdef __x86_64__
-  if (register_size (0) == 8)
+  if (register_size (regcache->tdesc, 0) == 8)
     {
       for (i = 0; i < X86_64_NUM_REGS; i++)
 	if (x86_64_regmap[i] != -1)
 	  supply_register (regcache, i, ((char *) buf) + x86_64_regmap[i]);
+
+#ifndef HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE
+      {
+        unsigned long base;
+        int lwpid = lwpid_of (current_thread);
+
+        if (ptrace (PTRACE_ARCH_PRCTL, lwpid, &base, ARCH_GET_FS) == 0)
+          supply_register_by_name (regcache, "fs_base", &base);
+
+        if (ptrace (PTRACE_ARCH_PRCTL, lwpid, &base, ARCH_GET_GS) == 0)
+          supply_register_by_name (regcache, "gs_base", &base);
+      }
+#endif
       return;
     }
 #endif
@@ -298,7 +373,7 @@ x86_store_gregset (struct regcache *regcache, const void *buf)
     supply_register (regcache, i, ((char *) buf) + i386_regmap[i]);
 
   supply_register_by_name (regcache, "orig_eax",
-			   ((char *) buf) + ORIG_EAX * 4);
+			   ((char *) buf) + ORIG_EAX * REGSIZE);
 }
 
 static void
@@ -354,11 +429,9 @@ x86_store_xstateregset (struct regcache *regcache, const void *buf)
    This is, presumably, to handle the case where PTRACE_[GS]ETFPXREGS
    doesn't work.  IWBN to avoid the duplication in the case where it
    does work.  Maybe the arch_setup routine could check whether it works
-   and update target_regsets accordingly, maybe by moving target_regsets
-   to linux_target_ops and set the right one there, rather than having to
-   modify the target_regsets global.  */
+   and update the supported regsets accordingly.  */
 
-struct regset_info target_regsets[] =
+static struct regset_info x86_regsets[] =
 {
 #ifdef HAVE_PTRACE_GETREGS
   { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
@@ -377,23 +450,25 @@ struct regset_info target_regsets[] =
     FP_REGS,
     x86_fill_fpregset, x86_store_fpregset },
 #endif /* HAVE_PTRACE_GETREGS */
-  { 0, 0, 0, -1, -1, NULL, NULL }
+  NULL_REGSET
 };
 
 static CORE_ADDR
 x86_get_pc (struct regcache *regcache)
 {
-  int use_64bit = register_size (0) == 8;
+  int use_64bit = register_size (regcache->tdesc, 0) == 8;
 
   if (use_64bit)
     {
-      unsigned long pc;
+      uint64_t pc;
+
       collect_register_by_name (regcache, "rip", &pc);
       return (CORE_ADDR) pc;
     }
   else
     {
-      unsigned int pc;
+      uint32_t pc;
+
       collect_register_by_name (regcache, "eip", &pc);
       return (CORE_ADDR) pc;
     }
@@ -402,21 +477,23 @@ x86_get_pc (struct regcache *regcache)
 static void
 x86_set_pc (struct regcache *regcache, CORE_ADDR pc)
 {
-  int use_64bit = register_size (0) == 8;
+  int use_64bit = register_size (regcache->tdesc, 0) == 8;
 
   if (use_64bit)
     {
-      unsigned long newpc = pc;
+      uint64_t newpc = pc;
+
       supply_register_by_name (regcache, "rip", &newpc);
     }
   else
     {
-      unsigned int newpc = pc;
+      uint32_t newpc = pc;
+
       supply_register_by_name (regcache, "eip", &newpc);
     }
 }
 
-static const unsigned char x86_breakpoint[] = { 0xCC };
+static const gdb_byte x86_breakpoint[] = { 0xCC };
 #define x86_breakpoint_len 1
 
 static int
@@ -431,148 +508,54 @@ x86_breakpoint_at (CORE_ADDR pc)
   return 0;
 }
 
-/* Support for debug registers.  */
-
-static unsigned long
-x86_linux_dr_get (ptid_t ptid, int regnum)
-{
-  int tid;
-  unsigned long value;
-
-  tid = ptid_get_lwp (ptid);
-
-  errno = 0;
-  value = ptrace (PTRACE_PEEKUSER, tid,
-		  offsetof (struct user, u_debugreg[regnum]), 0);
-  if (errno != 0)
-    error ("Couldn't read debug register");
-
-  return value;
-}
-
-static void
-x86_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
-{
-  int tid;
-
-  tid = ptid_get_lwp (ptid);
-
-  errno = 0;
-  ptrace (PTRACE_POKEUSER, tid,
-	  offsetof (struct user, u_debugreg[regnum]), value);
-  if (errno != 0)
-    error ("Couldn't write debug register");
-}
+/* Low-level function vector.  */
+struct x86_dr_low_type x86_dr_low =
+  {
+    x86_linux_dr_set_control,
+    x86_linux_dr_set_addr,
+    x86_linux_dr_get_addr,
+    x86_linux_dr_get_status,
+    x86_linux_dr_get_control,
+    sizeof (void *),
+  };
+
+/* Breakpoint/Watchpoint support.  */
 
 static int
-update_debug_registers_callback (struct inferior_list_entry *entry,
-				 void *pid_p)
+x86_supports_z_point_type (char z_type)
 {
-  struct lwp_info *lwp = (struct lwp_info *) entry;
-  int pid = *(int *) pid_p;
-
-  /* Only update the threads of this process.  */
-  if (pid_of (lwp) == pid)
+  switch (z_type)
     {
-      /* The actual update is done later just before resuming the lwp,
-	 we just mark that the registers need updating.  */
-      lwp->arch_private->debug_registers_changed = 1;
-
-      /* If the lwp isn't stopped, force it to momentarily pause, so
-	 we can update its debug registers.  */
-      if (!lwp->stopped)
-	linux_stop_lwp (lwp);
+    case Z_PACKET_SW_BP:
+    case Z_PACKET_HW_BP:
+    case Z_PACKET_WRITE_WP:
+    case Z_PACKET_ACCESS_WP:
+      return 1;
+    default:
+      return 0;
     }
-
-  return 0;
-}
-
-/* Update the inferior's debug register REGNUM from STATE.  */
-
-void
-i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
-{
-  /* Only update the threads of this process.  */
-  int pid = pid_of (get_thread_lwp (current_inferior));
-
-  if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
-    fatal ("Invalid debug register %d", regnum);
-
-  find_inferior (&all_lwps, update_debug_registers_callback, &pid);
-}
-
-/* Return the inferior's debug register REGNUM.  */
-
-CORE_ADDR
-i386_dr_low_get_addr (int regnum)
-{
-  struct lwp_info *lwp = get_thread_lwp (current_inferior);
-  ptid_t ptid = ptid_of (lwp);
-
-  /* DR6 and DR7 are retrieved with some other way.  */
-  gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
-
-  return x86_linux_dr_get (ptid, regnum);
-}
-
-/* Update the inferior's DR7 debug control register from STATE.  */
-
-void
-i386_dr_low_set_control (const struct i386_debug_reg_state *state)
-{
-  /* Only update the threads of this process.  */
-  int pid = pid_of (get_thread_lwp (current_inferior));
-
-  find_inferior (&all_lwps, update_debug_registers_callback, &pid);
-}
-
-/* Return the inferior's DR7 debug control register.  */
-
-unsigned
-i386_dr_low_get_control (void)
-{
-  struct lwp_info *lwp = get_thread_lwp (current_inferior);
-  ptid_t ptid = ptid_of (lwp);
-
-  return x86_linux_dr_get (ptid, DR_CONTROL);
 }
 
-/* Get the value of the DR6 debug status register from the inferior
-   and record it in STATE.  */
-
-unsigned
-i386_dr_low_get_status (void)
-{
-  struct lwp_info *lwp = get_thread_lwp (current_inferior);
-  ptid_t ptid = ptid_of (lwp);
-
-  return x86_linux_dr_get (ptid, DR_STATUS);
-}
-
-/* Breakpoint/Watchpoint support.  */
-
 static int
-x86_insert_point (char type, CORE_ADDR addr, int len)
+x86_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
+		  int size, struct raw_breakpoint *bp)
 {
   struct process_info *proc = current_process ();
+
   switch (type)
     {
-    case '0':
+    case raw_bkpt_type_hw:
+    case raw_bkpt_type_write_wp:
+    case raw_bkpt_type_access_wp:
       {
-	int ret;
-
-	ret = prepare_to_access_memory ();
-	if (ret)
-	  return -1;
-	ret = set_gdb_breakpoint_at (addr);
-	done_accessing_memory ();
-	return ret;
+	enum target_hw_bp_type hw_type
+	  = raw_bkpt_type_to_target_hw_bp_type (type);
+	struct x86_debug_reg_state *state
+	  = &proc->priv->arch_private->debug_reg_state;
+
+	return x86_dr_insert_watchpoint (state, hw_type, addr, size);
       }
-    case '2':
-    case '3':
-    case '4':
-      return i386_low_insert_watchpoint (&proc->private->arch_private->debug_reg_state,
-					 type, addr, len);
+
     default:
       /* Unsupported.  */
       return 1;
@@ -580,27 +563,24 @@ x86_insert_point (char type, CORE_ADDR addr, int len)
 }
 
 static int
-x86_remove_point (char type, CORE_ADDR addr, int len)
+x86_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
+		  int size, struct raw_breakpoint *bp)
 {
   struct process_info *proc = current_process ();
+
   switch (type)
     {
-    case '0':
+    case raw_bkpt_type_hw:
+    case raw_bkpt_type_write_wp:
+    case raw_bkpt_type_access_wp:
       {
-	int ret;
-
-	ret = prepare_to_access_memory ();
-	if (ret)
-	  return -1;
-	ret = delete_gdb_breakpoint_at (addr);
-	done_accessing_memory ();
-	return ret;
+	enum target_hw_bp_type hw_type
+	  = raw_bkpt_type_to_target_hw_bp_type (type);
+	struct x86_debug_reg_state *state
+	  = &proc->priv->arch_private->debug_reg_state;
+
+	return x86_dr_remove_watchpoint (state, hw_type, addr, size);
       }
-    case '2':
-    case '3':
-    case '4':
-      return i386_low_remove_watchpoint (&proc->private->arch_private->debug_reg_state,
-					 type, addr, len);
     default:
       /* Unsupported.  */
       return 1;
@@ -611,7 +591,7 @@ static int
 x86_stopped_by_watchpoint (void)
 {
   struct process_info *proc = current_process ();
-  return i386_low_stopped_by_watchpoint (&proc->private->arch_private->debug_reg_state);
+  return x86_dr_stopped_by_watchpoint (&proc->priv->arch_private->debug_reg_state);
 }
 
 static CORE_ADDR
@@ -619,8 +599,8 @@ x86_stopped_data_address (void)
 {
   struct process_info *proc = current_process ();
   CORE_ADDR addr;
-  if (i386_low_stopped_data_address (&proc->private->arch_private->debug_reg_state,
-				     &addr))
+  if (x86_dr_stopped_data_address (&proc->priv->arch_private->debug_reg_state,
+				   &addr))
     return addr;
   return 0;
 }
@@ -630,61 +610,49 @@ x86_stopped_data_address (void)
 static struct arch_process_info *
 x86_linux_new_process (void)
 {
-  struct arch_process_info *info = xcalloc (1, sizeof (*info));
+  struct arch_process_info *info = XCNEW (struct arch_process_info);
 
-  i386_low_init_dregs (&info->debug_reg_state);
+  x86_low_init_dregs (&info->debug_reg_state);
 
   return info;
 }
 
-/* Called when a new thread is detected.  */
+/* Target routine for linux_new_fork.  */
 
-static struct arch_lwp_info *
-x86_linux_new_thread (void)
+static void
+x86_linux_new_fork (struct process_info *parent, struct process_info *child)
 {
-  struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
+  /* These are allocated by linux_add_process.  */
+  gdb_assert (parent->priv != NULL
+	      && parent->priv->arch_private != NULL);
+  gdb_assert (child->priv != NULL
+	      && child->priv->arch_private != NULL);
 
-  info->debug_registers_changed = 1;
+  /* Linux kernel before 2.6.33 commit
+     72f674d203cd230426437cdcf7dd6f681dad8b0d
+     will inherit hardware debug registers from parent
+     on fork/vfork/clone.  Newer Linux kernels create such tasks with
+     zeroed debug registers.
 
-  return info;
+     GDB core assumes the child inherits the watchpoints/hw
+     breakpoints of the parent, and will remove them all from the
+     forked off process.  Copy the debug registers mirrors into the
+     new process so that all breakpoints and watchpoints can be
+     removed together.  The debug registers mirror will become zeroed
+     in the end before detaching the forked off process, thus making
+     this compatible with older Linux kernels too.  */
+
+  *child->priv->arch_private = *parent->priv->arch_private;
 }
 
-/* Called when resuming a thread.
-   If the debug regs have changed, update the thread's copies.  */
+/* See nat/x86-dregs.h.  */
 
-static void
-x86_linux_prepare_to_resume (struct lwp_info *lwp)
+struct x86_debug_reg_state *
+x86_debug_reg_state (pid_t pid)
 {
-  ptid_t ptid = ptid_of (lwp);
-  int clear_status = 0;
-
-  if (lwp->arch_private->debug_registers_changed)
-    {
-      int i;
-      int pid = ptid_get_pid (ptid);
-      struct process_info *proc = find_process_pid (pid);
-      struct i386_debug_reg_state *state
-	= &proc->private->arch_private->debug_reg_state;
-
-      for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
-	if (state->dr_ref_count[i] > 0)
-	  {
-	    x86_linux_dr_set (ptid, i, state->dr_mirror[i]);
-
-	    /* If we're setting a watchpoint, any change the inferior
-	       had done itself to the debug registers needs to be
-	       discarded, otherwise, i386_low_stopped_data_address can
-	       get confused.  */
-	    clear_status = 1;
-	  }
-
-      x86_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
-
-      lwp->arch_private->debug_registers_changed = 0;
-    }
+  struct process_info *proc = find_process_pid (pid);
 
-  if (clear_status || lwp->stopped_by_watchpoint)
-    x86_linux_dr_set (ptid, DR_STATUS, 0);
+  return &proc->priv->arch_private->debug_reg_state;
 }
 
 /* When GDBSERVER is built as a 64-bit application on linux, the
@@ -693,247 +661,28 @@ x86_linux_prepare_to_resume (struct lwp_info *lwp)
    as debugging it with a 32-bit GDBSERVER, we do the 32-bit <-> 64-bit
    conversion in-place ourselves.  */
 
-/* These types below (compat_*) define a siginfo type that is layout
-   compatible with the siginfo type exported by the 32-bit userspace
-   support.  */
-
-#ifdef __x86_64__
-
-typedef int compat_int_t;
-typedef unsigned int compat_uptr_t;
-
-typedef int compat_time_t;
-typedef int compat_timer_t;
-typedef int compat_clock_t;
-
-struct compat_timeval
-{
-  compat_time_t tv_sec;
-  int tv_usec;
-};
-
-typedef union compat_sigval
-{
-  compat_int_t sival_int;
-  compat_uptr_t sival_ptr;
-} compat_sigval_t;
-
-typedef struct compat_siginfo
-{
-  int si_signo;
-  int si_errno;
-  int si_code;
-
-  union
-  {
-    int _pad[((128 / sizeof (int)) - 3)];
-
-    /* kill() */
-    struct
-    {
-      unsigned int _pid;
-      unsigned int _uid;
-    } _kill;
-
-    /* POSIX.1b timers */
-    struct
-    {
-      compat_timer_t _tid;
-      int _overrun;
-      compat_sigval_t _sigval;
-    } _timer;
-
-    /* POSIX.1b signals */
-    struct
-    {
-      unsigned int _pid;
-      unsigned int _uid;
-      compat_sigval_t _sigval;
-    } _rt;
-
-    /* SIGCHLD */
-    struct
-    {
-      unsigned int _pid;
-      unsigned int _uid;
-      int _status;
-      compat_clock_t _utime;
-      compat_clock_t _stime;
-    } _sigchld;
-
-    /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
-    struct
-    {
-      unsigned int _addr;
-    } _sigfault;
-
-    /* SIGPOLL */
-    struct
-    {
-      int _band;
-      int _fd;
-    } _sigpoll;
-  } _sifields;
-} compat_siginfo_t;
-
-#define cpt_si_pid _sifields._kill._pid
-#define cpt_si_uid _sifields._kill._uid
-#define cpt_si_timerid _sifields._timer._tid
-#define cpt_si_overrun _sifields._timer._overrun
-#define cpt_si_status _sifields._sigchld._status
-#define cpt_si_utime _sifields._sigchld._utime
-#define cpt_si_stime _sifields._sigchld._stime
-#define cpt_si_ptr _sifields._rt._sigval.sival_ptr
-#define cpt_si_addr _sifields._sigfault._addr
-#define cpt_si_band _sifields._sigpoll._band
-#define cpt_si_fd _sifields._sigpoll._fd
-
-/* glibc at least up to 2.3.2 doesn't have si_timerid, si_overrun.
-   In their place is si_timer1,si_timer2.  */
-#ifndef si_timerid
-#define si_timerid si_timer1
-#endif
-#ifndef si_overrun
-#define si_overrun si_timer2
-#endif
-
-static void
-compat_siginfo_from_siginfo (compat_siginfo_t *to, siginfo_t *from)
-{
-  memset (to, 0, sizeof (*to));
-
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
-
-  if (to->si_code == SI_TIMER)
-    {
-      to->cpt_si_timerid = from->si_timerid;
-      to->cpt_si_overrun = from->si_overrun;
-      to->cpt_si_ptr = (intptr_t) from->si_ptr;
-    }
-  else if (to->si_code == SI_USER)
-    {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
-    }
-  else if (to->si_code < 0)
-    {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
-      to->cpt_si_ptr = (intptr_t) from->si_ptr;
-    }
-  else
-    {
-      switch (to->si_signo)
-	{
-	case SIGCHLD:
-	  to->cpt_si_pid = from->si_pid;
-	  to->cpt_si_uid = from->si_uid;
-	  to->cpt_si_status = from->si_status;
-	  to->cpt_si_utime = from->si_utime;
-	  to->cpt_si_stime = from->si_stime;
-	  break;
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	  to->cpt_si_addr = (intptr_t) from->si_addr;
-	  break;
-	case SIGPOLL:
-	  to->cpt_si_band = from->si_band;
-	  to->cpt_si_fd = from->si_fd;
-	  break;
-	default:
-	  to->cpt_si_pid = from->si_pid;
-	  to->cpt_si_uid = from->si_uid;
-	  to->cpt_si_ptr = (intptr_t) from->si_ptr;
-	  break;
-	}
-    }
-}
-
-static void
-siginfo_from_compat_siginfo (siginfo_t *to, compat_siginfo_t *from)
-{
-  memset (to, 0, sizeof (*to));
-
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
-
-  if (to->si_code == SI_TIMER)
-    {
-      to->si_timerid = from->cpt_si_timerid;
-      to->si_overrun = from->cpt_si_overrun;
-      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
-    }
-  else if (to->si_code == SI_USER)
-    {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
-    }
-  else if (to->si_code < 0)
-    {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
-      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
-    }
-  else
-    {
-      switch (to->si_signo)
-	{
-	case SIGCHLD:
-	  to->si_pid = from->cpt_si_pid;
-	  to->si_uid = from->cpt_si_uid;
-	  to->si_status = from->cpt_si_status;
-	  to->si_utime = from->cpt_si_utime;
-	  to->si_stime = from->cpt_si_stime;
-	  break;
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	  to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
-	  break;
-	case SIGPOLL:
-	  to->si_band = from->cpt_si_band;
-	  to->si_fd = from->cpt_si_fd;
-	  break;
-	default:
-	  to->si_pid = from->cpt_si_pid;
-	  to->si_uid = from->cpt_si_uid;
-	  to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
-	  break;
-	}
-    }
-}
-
-#endif /* __x86_64__ */
-
-/* Convert a native/host siginfo object, into/from the siginfo in the
+/* Convert a ptrace/host siginfo object, into/from the siginfo in the
    layout of the inferiors' architecture.  Returns true if any
    conversion was done; false otherwise.  If DIRECTION is 1, then copy
-   from INF to NATIVE.  If DIRECTION is 0, copy from NATIVE to
+   from INF to PTRACE.  If DIRECTION is 0, copy from PTRACE to
    INF.  */
 
 static int
-x86_siginfo_fixup (siginfo_t *native, void *inf, int direction)
+x86_siginfo_fixup (siginfo_t *ptrace, gdb_byte *inf, int direction)
 {
 #ifdef __x86_64__
-  /* Is the inferior 32-bit?  If so, then fixup the siginfo object.  */
-  if (register_size (0) == 4)
-    {
-      if (sizeof (siginfo_t) != sizeof (compat_siginfo_t))
-	fatal ("unexpected difference in siginfo");
-
-      if (direction == 0)
-	compat_siginfo_from_siginfo ((struct compat_siginfo *) inf, native);
-      else
-	siginfo_from_compat_siginfo (native, (struct compat_siginfo *) inf);
+  unsigned int machine;
+  int tid = lwpid_of (current_thread);
+  int is_elf64 = linux_pid_exe_is_elf_64_file (tid, &machine);
 
-      return 1;
-    }
+  /* Is the inferior 32-bit?  If so, then fixup the siginfo object.  */
+  if (!is_64bit_tdesc ())
+      return amd64_linux_siginfo_fixup_common (ptrace, inf, direction,
+					       FIXUP_32);
+  /* No fixup for native x32 GDB.  */
+  else if (!is_elf64 && sizeof (void *) == 8)
+    return amd64_linux_siginfo_fixup_common (ptrace, inf, direction,
+					     FIXUP_X32);
 #endif
 
   return 0;
@@ -941,219 +690,310 @@ x86_siginfo_fixup (siginfo_t *native, void *inf, int direction)
 
 static int use_xml;
 
-/* Update gdbserver_xmltarget.  */
+/* Format of XSAVE extended state is:
+	struct
+	{
+	  fxsave_bytes[0..463]
+	  sw_usable_bytes[464..511]
+	  xstate_hdr_bytes[512..575]
+	  avx_bytes[576..831]
+	  future_state etc
+	};
+
+  Same memory layout will be used for the coredump NT_X86_XSTATE
+  representing the XSAVE extended state registers.
+
+  The first 8 bytes of the sw_usable_bytes[464..467] is the OS enabled
+  extended state mask, which is the same as the extended control register
+  0 (the XFEATURE_ENABLED_MASK register), XCR0.  We can use this mask
+  together with the mask saved in the xstate_hdr_bytes to determine what
+  states the processor/OS supports and what state, used or initialized,
+  the process/thread is in.  */
+#define I386_LINUX_XSAVE_XCR0_OFFSET 464
+
+/* Does the current host support the GETFPXREGS request?  The header
+   file may or may not define it, and even if it is defined, the
+   kernel will return EIO if it's running on a pre-SSE processor.  */
+int have_ptrace_getfpxregs =
+#ifdef HAVE_PTRACE_GETFPXREGS
+  -1
+#else
+  0
+#endif
+;
+
+/* Get Linux/x86 target description from running target.  */
 
-static void
-x86_linux_update_xmltarget (void)
+static const struct target_desc *
+x86_linux_read_description (void)
 {
-  int pid;
+  unsigned int machine;
+  int is_elf64;
+  int xcr0_features;
+  int tid;
+  static uint64_t xcr0;
   struct regset_info *regset;
-  static unsigned long long xcr0;
-  static int have_ptrace_getregset = -1;
-#if !defined(__x86_64__) && defined(HAVE_PTRACE_GETFPXREGS)
-  static int have_ptrace_getfpxregs = -1;
-#endif
 
-  if (!current_inferior)
-    return;
+  tid = lwpid_of (current_thread);
 
-  /* Before changing the register cache internal layout or the target
-     regsets, flush the contents of the current valid caches back to
-     the threads.  */
-  regcache_invalidate ();
+  is_elf64 = linux_pid_exe_is_elf_64_file (tid, &machine);
 
-  pid = pid_of (get_thread_lwp (current_inferior));
-#ifdef __x86_64__
-  if (num_xmm_registers == 8)
-    init_registers_i386_linux ();
-  else
-    init_registers_amd64_linux ();
-#else
+  if (sizeof (void *) == 4)
     {
-# ifdef HAVE_PTRACE_GETFPXREGS
-      if (have_ptrace_getfpxregs == -1)
-	{
-	  elf_fpxregset_t fpxregs;
+      if (is_elf64 > 0)
+       error (_("Can't debug 64-bit process with 32-bit GDBserver"));
+#ifndef __x86_64__
+      else if (machine == EM_X86_64)
+       error (_("Can't debug x86-64 process with 32-bit GDBserver"));
+#endif
+    }
 
-	  if (ptrace (PTRACE_GETFPXREGS, pid, 0, (int) &fpxregs) < 0)
-	    {
-	      have_ptrace_getfpxregs = 0;
-	      x86_xcr0 = I386_XSTATE_X87_MASK;
-
-	      /* Disable PTRACE_GETFPXREGS.  */
-	      for (regset = target_regsets;
-		   regset->fill_function != NULL; regset++)
-		if (regset->get_request == PTRACE_GETFPXREGS)
-		  {
-		    regset->size = 0;
-		    break;
-		  }
-	    }
-	  else
-	    have_ptrace_getfpxregs = 1;
-	}
+#if !defined __x86_64__ && defined HAVE_PTRACE_GETFPXREGS
+  if (machine == EM_386 && have_ptrace_getfpxregs == -1)
+    {
+      elf_fpxregset_t fpxregs;
 
-      if (!have_ptrace_getfpxregs)
+      if (ptrace (PTRACE_GETFPXREGS, tid, 0, (long) &fpxregs) < 0)
 	{
-	  init_registers_i386_mmx_linux ();
-	  return;
+	  have_ptrace_getfpxregs = 0;
+	  have_ptrace_getregset = 0;
+	  return i386_linux_read_description (X86_XSTATE_X87);
 	}
-# endif
-      init_registers_i386_linux ();
+      else
+	have_ptrace_getfpxregs = 1;
     }
 #endif
 
   if (!use_xml)
     {
+      x86_xcr0 = X86_XSTATE_SSE_MASK;
+
       /* Don't use XML.  */
 #ifdef __x86_64__
-      if (num_xmm_registers == 8)
-	gdbserver_xmltarget = xmltarget_i386_linux_no_xml;
+      if (machine == EM_X86_64)
+	return tdesc_amd64_linux_no_xml;
       else
-	gdbserver_xmltarget = xmltarget_amd64_linux_no_xml;
-#else
-      gdbserver_xmltarget = xmltarget_i386_linux_no_xml;
 #endif
-
-      x86_xcr0 = I386_XSTATE_SSE_MASK;
-
-      return;
+	return tdesc_i386_linux_no_xml;
     }
 
-  /* Check if XSAVE extended state is supported.  */
   if (have_ptrace_getregset == -1)
     {
-      unsigned long long xstateregs[I386_XSTATE_SSE_SIZE / sizeof (long long)];
+      uint64_t xstateregs[(X86_XSTATE_SSE_SIZE / sizeof (uint64_t))];
       struct iovec iov;
 
       iov.iov_base = xstateregs;
       iov.iov_len = sizeof (xstateregs);
 
       /* Check if PTRACE_GETREGSET works.  */
-      if (ptrace (PTRACE_GETREGSET, pid, (unsigned int) NT_X86_XSTATE,
-		  &iov) < 0)
+      if (ptrace (PTRACE_GETREGSET, tid,
+		  (unsigned int) NT_X86_XSTATE, (long) &iov) < 0)
+	have_ptrace_getregset = 0;
+      else
 	{
-	  have_ptrace_getregset = 0;
-	  return;
+	  have_ptrace_getregset = 1;
+
+	  /* Get XCR0 from XSAVE extended state.  */
+	  xcr0 = xstateregs[(I386_LINUX_XSAVE_XCR0_OFFSET
+			     / sizeof (uint64_t))];
+
+	  /* Use PTRACE_GETREGSET if it is available.  */
+	  for (regset = x86_regsets;
+	       regset->fill_function != NULL; regset++)
+	    if (regset->get_request == PTRACE_GETREGSET)
+	      regset->size = X86_XSTATE_SIZE (xcr0);
+	    else if (regset->type != GENERAL_REGS)
+	      regset->size = 0;
 	}
-      else
-	have_ptrace_getregset = 1;
-
-      /* Get XCR0 from XSAVE extended state at byte 464.  */
-      xcr0 = xstateregs[464 / sizeof (long long)];
-
-      /* Use PTRACE_GETREGSET if it is available.  */
-      for (regset = target_regsets;
-	   regset->fill_function != NULL; regset++)
-	if (regset->get_request == PTRACE_GETREGSET)
-	  regset->size = I386_XSTATE_SIZE (xcr0);
-	else if (regset->type != GENERAL_REGS)
-	  regset->size = 0;
     }
 
-  if (have_ptrace_getregset)
+  /* Check the native XCR0 only if PTRACE_GETREGSET is available.  */
+  xcr0_features = (have_ptrace_getregset
+		   && (xcr0 & X86_XSTATE_ALL_MASK));
+
+  if (xcr0_features)
+    x86_xcr0 = xcr0;
+
+  if (machine == EM_X86_64)
     {
-      /* AVX is the highest feature we support.  */
-      if ((xcr0 & I386_XSTATE_AVX_MASK) == I386_XSTATE_AVX_MASK)
+#ifdef __x86_64__
+      const target_desc *tdesc = NULL;
+
+      if (xcr0_features)
 	{
-	  x86_xcr0 = xcr0;
+	  tdesc = amd64_linux_read_description (xcr0 & X86_XSTATE_ALL_MASK,
+						!is_elf64);
+	}
 
-#ifdef __x86_64__
-	  /* I386 has 8 xmm regs.  */
-	  if (num_xmm_registers == 8)
-	    init_registers_i386_avx_linux ();
-	  else
-	    init_registers_amd64_avx_linux ();
-#else
-	  init_registers_i386_avx_linux ();
+      if (tdesc == NULL)
+	tdesc = amd64_linux_read_description (X86_XSTATE_SSE_MASK, !is_elf64);
+      return tdesc;
 #endif
-	}
     }
+  else
+    {
+      const target_desc *tdesc = NULL;
+
+      if (xcr0_features)
+	  tdesc = i386_linux_read_description (xcr0 & X86_XSTATE_ALL_MASK);
+
+      if (tdesc == NULL)
+	tdesc = i386_linux_read_description (X86_XSTATE_SSE);
+
+      return tdesc;
+    }
+
+  gdb_assert_not_reached ("failed to return tdesc");
+}
+
+/* Callback for find_inferior.  Stops iteration when a thread with a
+   given PID is found.  */
+
+static int
+same_process_callback (struct inferior_list_entry *entry, void *data)
+{
+  int pid = *(int *) data;
+
+  return (ptid_get_pid (entry->id) == pid);
+}
+
+/* Callback for for_each_inferior.  Calls the arch_setup routine for
+   each process.  */
+
+static void
+x86_arch_setup_process_callback (struct inferior_list_entry *entry)
+{
+  int pid = ptid_get_pid (entry->id);
+
+  /* Look up any thread of this processes.  */
+  current_thread
+    = (struct thread_info *) find_inferior (&all_threads,
+					    same_process_callback, &pid);
+
+  the_low_target.arch_setup ();
+}
+
+/* Update all the target description of all processes; a new GDB
+   connected, and it may or not support xml target descriptions.  */
+
+static void
+x86_linux_update_xmltarget (void)
+{
+  struct thread_info *saved_thread = current_thread;
+
+  /* Before changing the register cache's internal layout, flush the
+     contents of the current valid caches back to the threads, and
+     release the current regcache objects.  */
+  regcache_release ();
+
+  for_each_inferior (&all_processes, x86_arch_setup_process_callback);
+
+  current_thread = saved_thread;
 }
 
 /* Process qSupported query, "xmlRegisters=".  Update the buffer size for
    PTRACE_GETREGSET.  */
 
 static void
-x86_linux_process_qsupported (const char *query)
+x86_linux_process_qsupported (char **features, int count)
 {
+  int i;
+
   /* Return if gdb doesn't support XML.  If gdb sends "xmlRegisters="
      with "i386" in qSupported query, it supports x86 XML target
      descriptions.  */
   use_xml = 0;
-  if (query != NULL && strncmp (query, "xmlRegisters=", 13) == 0)
+  for (i = 0; i < count; i++)
     {
-      char *copy = xstrdup (query + 13);
-      char *p;
+      const char *feature = features[i];
 
-      for (p = strtok (copy, ","); p != NULL; p = strtok (NULL, ","))
+      if (startswith (feature, "xmlRegisters="))
 	{
-	  if (strcmp (p, "i386") == 0)
+	  char *copy = xstrdup (feature + 13);
+	  char *p;
+
+	  for (p = strtok (copy, ","); p != NULL; p = strtok (NULL, ","))
 	    {
-	      use_xml = 1;
-	      break;
+	      if (strcmp (p, "i386") == 0)
+		{
+		  use_xml = 1;
+		  break;
+		}
 	    }
-	} 
 
-      free (copy);
+	  free (copy);
+	}
     }
-
   x86_linux_update_xmltarget ();
 }
 
-/* Initialize gdbserver for the architecture of the inferior.  */
+/* Common for x86/x86-64.  */
 
-static void
-x86_arch_setup (void)
-{
-  int pid = pid_of (get_thread_lwp (current_inferior));
-  unsigned int machine;
-  int is_elf64 = linux_pid_exe_is_elf_64_file (pid, &machine);
+static struct regsets_info x86_regsets_info =
+  {
+    x86_regsets, /* regsets */
+    0, /* num_regsets */
+    NULL, /* disabled_regsets */
+  };
 
-  if (sizeof (void *) == 4)
-    {
-      if (is_elf64 > 0)
-	error (_("Can't debug 64-bit process with 32-bit GDBserver"));
-#ifndef __x86_64__
-      else if (machine == EM_X86_64)
-	error (_("Can't debug x86-64 process with 32-bit GDBserver"));
+#ifdef __x86_64__
+static struct regs_info amd64_linux_regs_info =
+  {
+    NULL, /* regset_bitmap */
+    NULL, /* usrregs_info */
+    &x86_regsets_info
+  };
 #endif
-    }
+static struct usrregs_info i386_linux_usrregs_info =
+  {
+    I386_NUM_REGS,
+    i386_regmap,
+  };
+
+static struct regs_info i386_linux_regs_info =
+  {
+    NULL, /* regset_bitmap */
+    &i386_linux_usrregs_info,
+    &x86_regsets_info
+  };
 
+const struct regs_info *
+x86_linux_regs_info (void)
+{
 #ifdef __x86_64__
-  if (is_elf64 < 0)
-    {
-      /* This can only happen if /proc/<pid>/exe is unreadable,
-	 but "that can't happen" if we've gotten this far.
-	 Fall through and assume this is a 32-bit program.  */
-    }
-  else if (machine == EM_X86_64)
-    {
-      /* Amd64 doesn't have HAVE_LINUX_USRREGS.  */
-      the_low_target.num_regs = -1;
-      the_low_target.regmap = NULL;
-      the_low_target.cannot_fetch_register = NULL;
-      the_low_target.cannot_store_register = NULL;
+  if (is_64bit_tdesc ())
+    return &amd64_linux_regs_info;
+  else
+#endif
+    return &i386_linux_regs_info;
+}
 
-      /* Amd64 has 16 xmm regs.  */
-      num_xmm_registers = 16;
+/* Initialize the target description for the architecture of the
+   inferior.  */
 
-      x86_linux_update_xmltarget ();
-      return;
-    }
-#endif
+static void
+x86_arch_setup (void)
+{
+  current_process ()->tdesc = x86_linux_read_description ();
+}
 
-  /* Ok we have a 32-bit inferior.  */
+/* Fill *SYSNO and *SYSRET with the syscall nr trapped and the syscall return
+   code.  This should only be called if LWP got a SYSCALL_SIGTRAP.  */
 
-  the_low_target.num_regs = I386_NUM_REGS;
-  the_low_target.regmap = i386_regmap;
-  the_low_target.cannot_fetch_register = i386_cannot_fetch_register;
-  the_low_target.cannot_store_register = i386_cannot_store_register;
+static void
+x86_get_syscall_trapinfo (struct regcache *regcache, int *sysno)
+{
+  int use_64bit = register_size (regcache->tdesc, 0) == 8;
 
-  /* I386 has 8 xmm regs.  */
-  num_xmm_registers = 8;
+  if (use_64bit)
+    {
+      long l_sysno;
 
-  x86_linux_update_xmltarget ();
+      collect_register_by_name (regcache, "orig_rax", &l_sysno);
+      *sysno = (int) l_sysno;
+    }
+  else
+    collect_register_by_name (regcache, "orig_eax", sysno);
 }
 
 static int
@@ -1170,7 +1010,7 @@ append_insns (CORE_ADDR *to, size_t len, const unsigned char *buf)
 }
 
 static int
-push_opcode (unsigned char *buf, char *op)
+push_opcode (unsigned char *buf, const char *op)
 {
   unsigned char *buf_org = buf;
 
@@ -1238,10 +1078,10 @@ amd64_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
   buf[i++] = 0x41; buf[i++] = 0x51; /* push %r9 */
   buf[i++] = 0x41; buf[i++] = 0x50; /* push %r8 */
   buf[i++] = 0x9c; /* pushfq */
-  buf[i++] = 0x48; /* movl <addr>,%rdi */
+  buf[i++] = 0x48; /* movabs <addr>,%rdi */
   buf[i++] = 0xbf;
-  *((unsigned long *)(buf + i)) = (unsigned long) tpaddr;
-  i += sizeof (unsigned long);
+  memcpy (buf + i, &tpaddr, 8);
+  i += 8;
   buf[i++] = 0x57; /* push %rdi */
   append_insns (&buildaddr, i, buf);
 
@@ -1583,7 +1423,7 @@ x86_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
 				      char *err)
 {
 #ifdef __x86_64__
-  if (register_size (0) == 8)
+  if (is_64bit_tdesc ())
     return amd64_install_fast_tracepoint_jump_pad (tpoint, tpaddr,
 						   collector, lockaddr,
 						   orig_size, jump_entry,
@@ -1617,7 +1457,7 @@ x86_get_min_fast_tracepoint_insn_len (void)
 #ifdef __x86_64__
   /*  On x86-64, 5-byte jump instructions with a 4-byte offset are always
       used for fast tracepoints.  */
-  if (register_size (0) == 8)
+  if (is_64bit_tdesc ())
     return 5;
 #endif
 
@@ -1659,8 +1499,8 @@ add_insns (unsigned char *start, int len)
   CORE_ADDR buildaddr = current_insn_ptr;
 
   if (debug_threads)
-    fprintf (stderr, "Adding %d bytes of insn at %s\n",
-	     len, paddress (buildaddr));
+    debug_printf ("Adding %d bytes of insn at %s\n",
+		  len, paddress (buildaddr));
 
   append_insns (&buildaddr, len, start);
   current_insn_ptr = buildaddr;
@@ -1988,6 +1828,8 @@ amd64_emit_call (CORE_ADDR fn)
   else
     {
       int offset32 = offset64; /* we know we can't overflow here.  */
+
+      buf[i++] = 0xe8; /* call <reladdr> */
       memcpy (buf + i, &offset32, 4);
       i += 4;
     }
@@ -2960,34 +2802,71 @@ static struct emit_ops *
 x86_emit_ops (void)
 {
 #ifdef __x86_64__
-  int use_64bit = register_size (0) == 8;
-
-  if (use_64bit)
+  if (is_64bit_tdesc ())
     return &amd64_emit_ops;
   else
 #endif
     return &i386_emit_ops;
 }
 
+/* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
+
+static const gdb_byte *
+x86_sw_breakpoint_from_kind (int kind, int *size)
+{
+  *size = x86_breakpoint_len;
+  return x86_breakpoint;
+}
+
+static int
+x86_supports_range_stepping (void)
+{
+  return 1;
+}
+
+/* Implementation of linux_target_ops method "supports_hardware_single_step".
+ */
+
+static int
+x86_supports_hardware_single_step (void)
+{
+  return 1;
+}
+
+static int
+x86_get_ipa_tdesc_idx (void)
+{
+  struct regcache *regcache = get_thread_regcache (current_thread, 0);
+  const struct target_desc *tdesc = regcache->tdesc;
+
+#ifdef __x86_64__
+  return amd64_get_ipa_tdesc_idx (tdesc);
+#endif
+
+  if (tdesc == tdesc_i386_linux_no_xml)
+    return X86_TDESC_SSE;
+
+  return i386_get_ipa_tdesc_idx (tdesc);
+}
+
 /* This is initialized assuming an amd64 target.
    x86_arch_setup will correct it for i386 or amd64 targets.  */
 
 struct linux_target_ops the_low_target =
 {
   x86_arch_setup,
-  -1,
-  NULL,
-  NULL,
-  NULL,
-  NULL,
+  x86_linux_regs_info,
+  x86_cannot_fetch_register,
+  x86_cannot_store_register,
   NULL, /* fetch_register */
   x86_get_pc,
   x86_set_pc,
-  x86_breakpoint,
-  x86_breakpoint_len,
+  NULL, /* breakpoint_kind_from_pc */
+  x86_sw_breakpoint_from_kind,
   NULL,
   1,
   x86_breakpoint_at,
+  x86_supports_z_point_type,
   x86_insert_point,
   x86_remove_point,
   x86_stopped_by_watchpoint,
@@ -3001,6 +2880,7 @@ struct linux_target_ops the_low_target =
   x86_siginfo_fixup,
   x86_linux_new_process,
   x86_linux_new_thread,
+  x86_linux_new_fork,
   x86_linux_prepare_to_resume,
   x86_linux_process_qsupported,
   x86_supports_tracepoints,
@@ -3008,4 +2888,33 @@ struct linux_target_ops the_low_target =
   x86_install_fast_tracepoint_jump_pad,
   x86_emit_ops,
   x86_get_min_fast_tracepoint_insn_len,
+  x86_supports_range_stepping,
+  NULL, /* breakpoint_kind_from_current_state */
+  x86_supports_hardware_single_step,
+  x86_get_syscall_trapinfo,
+  x86_get_ipa_tdesc_idx,
 };
+
+void
+initialize_low_arch (void)
+{
+  /* Initialize the Linux target descriptions.  */
+#ifdef __x86_64__
+  tdesc_amd64_linux_no_xml = XNEW (struct target_desc);
+  copy_target_description (tdesc_amd64_linux_no_xml,
+			   amd64_linux_read_description (X86_XSTATE_SSE_MASK,
+							 false));
+  tdesc_amd64_linux_no_xml->xmltarget = xmltarget_amd64_linux_no_xml;
+#endif
+
+#if GDB_SELF_TEST
+  initialize_low_tdesc ();
+#endif
+
+  tdesc_i386_linux_no_xml = XNEW (struct target_desc);
+  copy_target_description (tdesc_i386_linux_no_xml,
+			   i386_linux_read_description (X86_XSTATE_SSE_MASK));
+  tdesc_i386_linux_no_xml->xmltarget = xmltarget_i386_linux_no_xml;
+
+  initialize_regsets_info (&x86_regsets_info);
+}