* linux-low.h (struct linux_target_ops): Replace left_pad_xfer field

	by collect_ptrace_register and supply_ptrace_register hooks.
	* linux-low.c (fetch_register): Use supply_ptrace_register callback
	instead of checking for the_low_target.left_pad_xfer.
	(usr_store_inferior_registers): Use collect_ptrace_register callback
	instead of checking for the_low_target.left_pad_xfer.

	* linux-s390-low.c (s390_collect_ptrace_register): New function.
	(s390_supply_ptrace_register): Likewise.
	(s390_fill_gregset): Call s390_collect_ptrace_register.
	(the_low_target): Update.

	* linux-ppc64-low.c (ppc_collect_ptrace_register): New function.
	(ppc_supply_ptrace_register): Likewise.
	(the_low_target): Update.

	* linux-i386-low.c (the_low_target): Update.
	* linux-x86-64-low.c (the_low_target): Update.

7 files changed, 104 insertions, 15 deletions

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index ae63d4e..d8e5c7f 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,5 +1,26 @@
 2008-02-27  Ulrich Weigand  <uweigand@de.ibm.com>
 
+	* linux-low.h (struct linux_target_ops): Replace left_pad_xfer field
+	by collect_ptrace_register and supply_ptrace_register hooks.
+	* linux-low.c (fetch_register): Use supply_ptrace_register callback
+	instead of checking for the_low_target.left_pad_xfer.
+	(usr_store_inferior_registers): Use collect_ptrace_register callback
+	instead of checking for the_low_target.left_pad_xfer.
+
+	* linux-s390-low.c (s390_collect_ptrace_register): New function.
+	(s390_supply_ptrace_register): Likewise.
+	(s390_fill_gregset): Call s390_collect_ptrace_register.
+	(the_low_target): Update.
+
+	* linux-ppc64-low.c (ppc_collect_ptrace_register): New function.
+	(ppc_supply_ptrace_register): Likewise.
+	(the_low_target): Update.
+
+	* linux-i386-low.c (the_low_target): Update.
+	* linux-x86-64-low.c (the_low_target): Update.
+
+2008-02-27  Ulrich Weigand  <uweigand@de.ibm.com>
+
 	* configure.srv [s390x-*-linux*]: Set srv_regobj to include both
 	reg-s390.o and reg-s390x.o.
 
diff --git a/gdb/gdbserver/linux-i386-low.c b/gdb/gdbserver/linux-i386-low.c
index 433d085..c3cccb6 100644
--- a/gdb/gdbserver/linux-i386-low.c
+++ b/gdb/gdbserver/linux-i386-low.c
@@ -205,6 +205,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   NULL,
   NULL,
-  0,
+  NULL,
+  NULL,
   "i386"
 };
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 732aafb..1d2b422 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -1401,10 +1401,9 @@ fetch_register (int regno)
 	  goto error_exit;
 	}
     }
-  if (the_low_target.left_pad_xfer
-      && register_size (regno) < sizeof (PTRACE_XFER_TYPE))
-    supply_register (regno, (buf + sizeof (PTRACE_XFER_TYPE)
-			     - register_size (regno)));
+
+  if (the_low_target.supply_ptrace_register)
+    the_low_target.supply_ptrace_register (regno, buf);
   else
     supply_register (regno, buf);
 
@@ -1448,12 +1447,12 @@ usr_store_inferior_registers (int regno)
 	     & - sizeof (PTRACE_XFER_TYPE);
       buf = alloca (size);
       memset (buf, 0, size);
-      if (the_low_target.left_pad_xfer
-	  && register_size (regno) < sizeof (PTRACE_XFER_TYPE))
-	collect_register (regno, (buf + sizeof (PTRACE_XFER_TYPE)
-				  - register_size (regno)));
+
+      if (the_low_target.collect_ptrace_register)
+	the_low_target.collect_ptrace_register (regno, buf);
       else
 	collect_register (regno, buf);
+
       for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
 	{
 	  errno = 0;
diff --git a/gdb/gdbserver/linux-low.h b/gdb/gdbserver/linux-low.h
index 698a1b0..ccbeb25 100644
--- a/gdb/gdbserver/linux-low.h
+++ b/gdb/gdbserver/linux-low.h
@@ -69,9 +69,10 @@ struct linux_target_ops
   int (*stopped_by_watchpoint) (void);
   CORE_ADDR (*stopped_data_address) (void);
 
-  /* Whether to left-pad registers for PEEKUSR/POKEUSR if they are smaller
-     than an xfer unit.  */
-  int left_pad_xfer;
+  /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
+     for registers smaller than an xfer unit).  */
+  void (*collect_ptrace_register) (int regno, char *buf);
+  void (*supply_ptrace_register) (int regno, const char *buf);
 
   /* What string to report to GDB when it asks for the architecture,
      or NULL not to answer.  */
diff --git a/gdb/gdbserver/linux-ppc64-low.c b/gdb/gdbserver/linux-ppc64-low.c
index 3897d73b..f216e9d 100644
--- a/gdb/gdbserver/linux-ppc64-low.c
+++ b/gdb/gdbserver/linux-ppc64-low.c
@@ -64,6 +64,26 @@ ppc_cannot_fetch_register (int regno)
   return 0;
 }
 
+static void
+ppc_collect_ptrace_register (int regno, char *buf)
+{
+  int size = register_size (regno);
+  if (size < sizeof (long))
+    collect_register (regno, buf + sizeof (long) - size);
+  else
+    collect_register (regno, buf);
+}
+
+static void
+ppc_supply_ptrace_register (int regno, const char *buf)
+{
+  int size = register_size (regno);
+  if (size < sizeof (long))
+    supply_register (regno, buf + sizeof (long) - size);
+  else
+    supply_register (regno, buf);
+}
+
 static CORE_ADDR
 ppc_get_pc (void)
 {
@@ -187,5 +207,6 @@ struct linux_target_ops the_low_target = {
   NULL,
   NULL,
   NULL,
-  1
+  ppc_collect_ptrace_register,
+  ppc_supply_ptrace_register,
 };
diff --git a/gdb/gdbserver/linux-s390-low.c b/gdb/gdbserver/linux-s390-low.c
index d6739ab..090ef27 100644
--- a/gdb/gdbserver/linux-s390-low.c
+++ b/gdb/gdbserver/linux-s390-low.c
@@ -79,6 +79,45 @@ s390_cannot_store_register (int regno)
   return 0;
 }
 
+static void
+s390_collect_ptrace_register (int regno, char *buf)
+{
+  int size = register_size (regno);
+  if (size < sizeof (long))
+    {
+      memset (buf, 0, sizeof (long));
+
+      if (regno == find_regno ("pswa")
+	  || (regno >= find_regno ("r0") && regno <= find_regno ("r15")))
+	collect_register (regno, buf + sizeof (long) - size);
+      else
+	collect_register (regno, buf);
+
+      /* When debugging a 32-bit inferior on a 64-bit host, make sure
+	 the 31-bit addressing mode bit is set in the PSW mask.  */
+      if (regno == find_regno ("pswm"))
+	buf[size] |= 0x80;
+    }
+  else
+    collect_register (regno, buf);
+}
+
+static void
+s390_supply_ptrace_register (int regno, const char *buf)
+{
+  int size = register_size (regno);
+  if (size < sizeof (long))
+    {
+      if (regno == find_regno ("pswa")
+	  || (regno >= find_regno ("r0") && regno <= find_regno ("r15")))
+	supply_register (regno, buf + sizeof (long) - size);
+      else
+	supply_register (regno, buf);
+    }
+  else
+    supply_register (regno, buf);
+}
+
 /* Provide only a fill function for the general register set.  ps_lgetregs
    will use this for NPTL support.  */
 
@@ -87,7 +126,7 @@ static void s390_fill_gregset (void *buf)
   int i;
 
   for (i = 0; i < 34; i++)
-    collect_register (i, (char *) buf + s390_regmap[i]);
+    s390_collect_ptrace_register (i, (char *) buf + s390_regmap[i]);
 }
 
 struct regset_info target_regsets[] = {
@@ -179,5 +218,11 @@ struct linux_target_ops the_low_target = {
   NULL,
   s390_breakpoint_len,
   s390_breakpoint_at,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  s390_collect_ptrace_register,
+  s390_supply_ptrace_register,
 };
 
diff --git a/gdb/gdbserver/linux-x86-64-low.c b/gdb/gdbserver/linux-x86-64-low.c
index 80f5c6d..b4a2f6b 100644
--- a/gdb/gdbserver/linux-x86-64-low.c
+++ b/gdb/gdbserver/linux-x86-64-low.c
@@ -179,6 +179,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   NULL,
   NULL,
-  0,
+  NULL,
+  NULL,
   "i386:x86-64",
 };