PR threads/10729

	* linux-x86-low.c (update_debug_registers_callback): New.
	(i386_dr_low_set_addr): Use it.
	(i386_dr_low_get_addr): New.
	(i386_dr_low_set_control): Use update_debug_registers_callback.
	(i386_dr_low_get_control): New.
	(i386_dr_low_get_status): Adjust.
	* linux-low.c (linux_stop_lwp): New.
	* linux-low.h (linux_stop_lwp): Declare.

	* i386-low.c (I386_DR_GET_RW_LEN): Take the dr7 contents as
	argument instead of a i386_debug_reg_state.
	(I386_DR_WATCH_HIT): Take the dr6 contents as argument instead of
	a i386_debug_reg_state.
	(i386_insert_aligned_watchpoint): Adjust.
	(i386_remove_aligned_watchpoint): Adjust.
	(i386_low_stopped_data_address): Read the debug registers from the
	inferior instead of from the mirrors.
	* i386-low.h (struct i386_debug_reg_state): Extend comment.
	(i386_dr_low_get_addr): Declare.
	(i386_dr_low_get_control): Declare.
	(i386_dr_low_get_status): Change prototype.

	* win32-i386-low.c (dr_status_mirror, dr_control_mirror): New globals.
	(i386_dr_low_get_addr): New.
	(i386_dr_low_get_control): New.
	(i386_dr_low_get_status): Adjust prototype.  Return
	dr_status_mirror.
	(i386_initial_stuff): Clear dr_status_mirror and
	dr_control_mirror.
	(i386_get_thread_context): Adjust.
	(i386_set_thread_context): Adjust.
	(i386_thread_added): Adjust.

1 files changed, 15 insertions, 10 deletions

diff --git a/gdb/gdbserver/i386-low.c b/gdb/gdbserver/i386-low.c
index 494b8087f2a..f13ae269cf4 100644
--- a/gdb/gdbserver/i386-low.c
+++ b/gdb/gdbserver/i386-low.c
@@ -132,12 +132,12 @@ enum target_hw_bp_type
   } while (0)
 
 /* Get from DR7 the RW and LEN fields for the I'th debug register.  */
-#define I386_DR_GET_RW_LEN(state, i) \
-  (((state)->dr_control_mirror \
+#define I386_DR_GET_RW_LEN(dr7, i) \
+  (((dr7) \
     >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
 
 /* Did the watchpoint whose address is in the I'th register break?  */
-#define I386_DR_WATCH_HIT(state,i) ((state)->dr_status_mirror & (1 << (i)))
+#define I386_DR_WATCH_HIT(dr6, i) ((dr6) & (1 << (i)))
 
 /* A macro to loop over all debug registers.  */
 #define ALL_DEBUG_REGISTERS(i)	for (i = 0; i < DR_NADDR; i++)
@@ -271,7 +271,7 @@ i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
     {
       if (!I386_DR_VACANT (state, i)
 	  && state->dr_mirror[i] == addr
-	  && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
+	  && I386_DR_GET_RW_LEN (state->dr_control_mirror, i) == len_rw_bits)
 	{
 	  state->dr_ref_count[i]++;
 	  return 0;
@@ -329,7 +329,7 @@ i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
     {
       if (!I386_DR_VACANT (state, i)
 	  && state->dr_mirror[i] == addr
-	  && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
+	  && I386_DR_GET_RW_LEN (state->dr_control_mirror, i) == len_rw_bits)
 	{
 	  if (--state->dr_ref_count[i] == 0) /* No longer in use?  */
 	    {
@@ -539,21 +539,26 @@ i386_low_stopped_data_address (struct i386_debug_reg_state *state,
   CORE_ADDR addr = 0;
   int i;
   int rc = 0;
+  unsigned status;
+  unsigned control;
 
-  /* Get dr_status_mirror for use by I386_DR_WATCH_HIT.  */
-  i386_dr_low_get_status (state);
+  /* Get the current values the inferior has.  If the thread was
+     running when we last changed watchpoints, the mirror no longer
+     represents what was set in this LWP's debug registers.  */
+  status = i386_dr_low_get_status ();
+  control = i386_dr_low_get_control ();
 
   ALL_DEBUG_REGISTERS (i)
     {
-      if (I386_DR_WATCH_HIT (state, i)
+      if (I386_DR_WATCH_HIT (status, i)
 	  /* This second condition makes sure DRi is set up for a data
 	     watchpoint, not a hardware breakpoint.  The reason is
 	     that GDB doesn't call the target_stopped_data_address
 	     method except for data watchpoints.  In other words, I'm
 	     being paranoiac.  */
-	  && I386_DR_GET_RW_LEN (state, i) != 0)
+	  && I386_DR_GET_RW_LEN (control, i) != 0)
 	{
-	  addr = state->dr_mirror[i];
+	  addr = i386_dr_low_get_addr (i);
 	  rc = 1;
 	  if (debug_hw_points)
 	    i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);