* linux-low.c (linux_prepare_to_access_memory): New.

	(linux_unprepare_to_access_memory): New.
	(linux_target_ops): Install them.
	* server.c (read_memory): Rename to ...
	(gdb_read_memory): ... this.  Use
	prepare_to_access_memory/prepare_to_access_memory.
	(write_memory): Rename to ...
	(gdb_write_memory): ... this.  Use
	prepare_to_access_memory/prepare_to_access_memory.
	(handle_search_memory_1): Adjust.
	(process_serial_event): Adjust.
	* target.h (struct target_ops): New fields
	prepare_to_access_memory and unprepare_to_access_memory.
	(prepare_to_access_memory, unprepare_to_access_memory): New.
	* linux-x86-low.c (x86_insert_point, x86_remove_point): Use
	prepare_to_access_memory/prepare_to_access_memory.
	* nto-low.c (nto_target_ops): Adjust.
	* spu-low.c (spu_target_ops): Adjust.
	* win32-low.c (win32_target_ops): Adjust.

1 files changed, 29 insertions, 0 deletions

diff --git a/gdb/gdbserver/target.h b/gdb/gdbserver/target.h
index 1f9f921..8126f85 100644
--- a/gdb/gdbserver/target.h
+++ b/gdb/gdbserver/target.h
@@ -181,6 +181,23 @@ struct target_ops
 
   void (*store_registers) (struct regcache *regcache, int regno);
 
+  /* Prepare to read or write memory from the inferior process.
+     Targets use this to do what is necessary to get the state of the
+     inferior such that it is possible to access memory.
+
+     This should generally only be called from client facing routines,
+     such as gdb_read_memory/gdb_write_memory, or the insert_point
+     callbacks.
+
+     Like `read_memory' and `write_memory' below, returns 0 on success
+     and errno on failure.  */
+
+  int (*prepare_to_access_memory) (void);
+
+  /* Undo the effects of prepare_to_access_memory.  */
+
+  void (*unprepare_to_access_memory) (void);
+
   /* Read memory from the inferior process.  This should generally be
      called through read_inferior_memory, which handles breakpoint shadowing.
 
@@ -469,6 +486,18 @@ int start_non_stop (int nonstop);
 ptid_t mywait (ptid_t ptid, struct target_waitstatus *ourstatus, int options,
 	       int connected_wait);
 
+#define prepare_to_access_memory()		\
+  (the_target->prepare_to_access_memory		\
+   ? (*the_target->prepare_to_access_memory) () \
+   : 0)
+
+#define unprepare_to_access_memory()			\
+  do							\
+    {							\
+      if (the_target->unprepare_to_access_memory)     	\
+	(*the_target->unprepare_to_access_memory) ();  	\
+    } while (0)
+
 int read_inferior_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len);
 
 int write_inferior_memory (CORE_ADDR memaddr, const unsigned char *myaddr,