Move low-level Linux x86 debug register code to a shared file

This commit moves the now-identical low-level Linux x86 debug register
code from gdb/x86-linux-nat.c and gdb/gdbserver/linux-x86-low.c into a
new shared file gdb/nat/x86-linux-dregs.c.

gdb/ChangeLog:

	* nat/x86-linux-dregs.h: New file.
	* nat/x86-linux-dregs.c: Likewise.
	* Makefile.in (HFILES_NO_SRCDIR): Add nat/x86-linux-dregs.h.
	(x86-linux-dregs.o): New rule.
	* config/i386/linux.mh (NATDEPFILES): Add x86-linux-dregs.o.
	* config/i386/linux64.mh (NATDEPFILES): Likewise.
	* x86-linux-nat.c: Include nat/x86-linux-dregs.h.
	(u_debugreg_offset): Moved to nat/x86-linux-dregs.c.
	(x86_linux_dr_get): Likewise.
	(x86_linux_dr_set): Likewise.
	(x86_linux_dr_get_addr): Likewise.
	(x86_linux_dr_get_control): Likewise.
	(x86_linux_dr_get_status): Likewise.
	(update_debug_registers_callback): Likewise.
	(x86_linux_dr_set_control): Likewise.
	(x86_linux_dr_set_addr): Likewise.
	(x86_linux_update_debug_registers): Likewise.

gdb/gdbserver/ChangeLog:

	* Makefile.in (x86-linux-dregs.o): New rule.
	* configure.srv: Add x86-linux-dregs.o to relevant targets.
	* linux-x86-low.c: Include nat/x86-linux-dregs.h.
	(u_debugreg_offset): Moved to nat/x86-linux-dregs.c.
	(x86_linux_dr_get): Likewise.
	(x86_linux_dr_set): Likewise.
	(update_debug_registers_callback): Likewise.
	(x86_linux_dr_set_addr): Likewise.
	(x86_linux_dr_get_addr): Likewise.
	(x86_linux_dr_set_control): Likewise.
	(x86_linux_dr_get_control): Likewise.
	(x86_linux_dr_get_status): Likewise.
	(x86_linux_update_debug_registers): Likewise.

1 files changed, 1 insertions, 167 deletions

diff --git a/gdb/x86-linux-nat.c b/gdb/x86-linux-nat.c
index 9eb82c5..84021fb 100644
--- a/gdb/x86-linux-nat.c
+++ b/gdb/x86-linux-nat.c
@@ -40,6 +40,7 @@
 #include "nat/linux-btrace.h"
 #include "nat/linux-nat.h"
 #include "nat/x86-linux.h"
+#include "nat/x86-linux-dregs.h"
 
 /* Per-thread arch-specific data we want to keep.  */
 
@@ -51,173 +52,6 @@ struct arch_lwp_info
 
 /* Does the current host support PTRACE_GETREGSET?  */
 int have_ptrace_getregset = -1;
-
-
-/* Return the offset of REGNUM in the u_debugreg field of struct
-   user.  */
-
-static int
-u_debugreg_offset (int regnum)
-{
-  return (offsetof (struct user, u_debugreg)
-	  + sizeof (((struct user *) 0)->u_debugreg[0]) * regnum);
-}
-
-/* Support for debug registers.  */
-
-/* Get debug register REGNUM value from the LWP specified by PTID.  */
-
-static unsigned long
-x86_linux_dr_get (ptid_t ptid, int regnum)
-{
-  int tid;
-  unsigned long value;
-
-  gdb_assert (ptid_lwp_p (ptid));
-  tid = ptid_get_lwp (ptid);
-
-  errno = 0;
-  value = ptrace (PTRACE_PEEKUSER, tid, u_debugreg_offset (regnum), 0);
-
-  if (errno != 0)
-    perror_with_name (_("Couldn't read debug register"));
-
-  return value;
-}
-
-/* Set debug register REGNUM to VALUE in the LWP specified by PTID.  */
-
-static void
-x86_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
-{
-  int tid;
-
-  gdb_assert (ptid_lwp_p (ptid));
-  tid = ptid_get_lwp (ptid);
-
-  errno = 0;
-  ptrace (PTRACE_POKEUSER, tid, u_debugreg_offset (regnum), value);
-  if (errno != 0)
-    perror_with_name (_("Couldn't write debug register"));
-}
-
-/* Return the address stored in the current inferior's debug register
-   REGNUM.  */
-
-static CORE_ADDR
-x86_linux_dr_get_addr (int regnum)
-{
-  gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
-
-  return x86_linux_dr_get (current_lwp_ptid (), regnum);
-}
-
-/* Return the value stored in the current inferior's debug control
-   register.  */
-
-static unsigned long
-x86_linux_dr_get_control (void)
-{
-  return x86_linux_dr_get (current_lwp_ptid (), DR_CONTROL);
-}
-
-/* Return the value stored in the current inferior's debug status
-   register.  */
-
-static unsigned long
-x86_linux_dr_get_status (void)
-{
-  return x86_linux_dr_get (current_lwp_ptid (), DR_STATUS);
-}
-
-/* Callback for iterate_over_lwps.  Mark that our local mirror of
-   LWP's debug registers has been changed, and cause LWP to stop if
-   it isn't already.  Values are written from our local mirror to
-   the actual debug registers immediately prior to LWP resuming.  */
-
-static int
-update_debug_registers_callback (struct lwp_info *lwp, void *arg)
-{
-  lwp_set_debug_registers_changed (lwp, 1);
-
-  if (!lwp_is_stopped (lwp))
-    linux_stop_lwp (lwp);
-
-  /* Continue the iteration.  */
-  return 0;
-}
-
-/* Store CONTROL in the debug control registers of all LWPs of the
-   current inferior.  */
-
-static void
-x86_linux_dr_set_control (unsigned long control)
-{
-  ptid_t pid_ptid = pid_to_ptid (ptid_get_pid (current_lwp_ptid ()));
-
-  iterate_over_lwps (pid_ptid, update_debug_registers_callback, NULL);
-}
-
-/* Store ADDR in debug register REGNUM of all LWPs of the current
-   inferior.  */
-
-static void
-x86_linux_dr_set_addr (int regnum, CORE_ADDR addr)
-{
-  ptid_t pid_ptid = pid_to_ptid (ptid_get_pid (current_lwp_ptid ()));
-
-  gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
-
-  iterate_over_lwps (pid_ptid, update_debug_registers_callback, NULL);
-}
-
-/* Update the thread's debug registers if the values in our local
-   mirror have been changed.  */
-
-static void
-x86_linux_update_debug_registers (struct lwp_info *lwp)
-{
-  ptid_t ptid = ptid_of_lwp (lwp);
-  int clear_status = 0;
-
-  gdb_assert (lwp_is_stopped (lwp));
-
-  if (lwp_debug_registers_changed (lwp))
-    {
-      struct x86_debug_reg_state *state
-	= x86_debug_reg_state (ptid_get_pid (ptid));
-      int i;
-
-      /* Prior to Linux kernel 2.6.33 commit
-	 72f674d203cd230426437cdcf7dd6f681dad8b0d, setting DR0-3 to
-	 a value that did not match what was enabled in DR_CONTROL
-	 resulted in EINVAL.  To avoid this we zero DR_CONTROL before
-	 writing address registers, only writing DR_CONTROL's actual
-	 value once all the addresses are in place.  */
-      x86_linux_dr_set (ptid, DR_CONTROL, 0);
-
-      ALL_DEBUG_ADDRESS_REGISTERS (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
-	       has made to its debug registers needs to be discarded
-	       to avoid x86_stopped_data_address getting confused.  */
-	    clear_status = 1;
-	  }
-
-      /* If DR_CONTROL is supposed to be zero then it's already set.  */
-      if (state->dr_control_mirror != 0)
-	x86_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
-
-      lwp_set_debug_registers_changed (lwp, 0);
-    }
-
-  if (clear_status
-      || lwp_stop_reason (lwp) == TARGET_STOPPED_BY_WATCHPOINT)
-    x86_linux_dr_set (ptid, DR_STATUS, 0);
-}
 
 /* Called prior to resuming a thread.  */