Update release making notes.

[deliverable/binutils-gdb.git] / gdb / gdbserver / linux-mips-low.c

diff --git a/gdb/gdbserver/linux-mips-low.c b/gdb/gdbserver/linux-mips-low.c
index d423633747acb7923a274f2dcf2819335d493c37..f94e141be79ffcd472a65f752adef14bb30ba1df 100644 (file)
--- a/gdb/gdbserver/linux-mips-low.c
+++ b/gdb/gdbserver/linux-mips-low.c
@@ -1,5 +1,5 @@
 /* GNU/Linux/MIPS specific low level interface, for the remote server for GDB.
-   Copyright (C) 1995-2018 Free Software Foundation, Inc.
+   Copyright (C) 1995-2020 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -198,8 +198,8 @@ struct arch_lwp_info
 
 /* Pseudo registers can not be read.  ptrace does not provide a way to
    read (or set) PS_REGNUM, and there's no point in reading or setting
-   ZERO_REGNUM.  We also can not set BADVADDR, CAUSE, or FCRIR via
-   ptrace().  */
+   ZERO_REGNUM, it's always 0.  We also can not set BADVADDR, CAUSE,
+   or FCRIR via ptrace().  */
 
 static int
 mips_cannot_fetch_register (int regno)
@@ -211,6 +211,10 @@ mips_cannot_fetch_register (int regno)
 
   tdesc = current_process ()->tdesc;
 
+  /* On n32 we can't access 64-bit registers via PTRACE_PEEKUSR.  */
+  if (register_size (tdesc, regno) > sizeof (PTRACE_XFER_TYPE))
+    return 1;
+
   if (find_regno (tdesc, "r0") == regno)
     return 1;
 
@@ -227,6 +231,10 @@ mips_cannot_store_register (int regno)
 
   tdesc = current_process ()->tdesc;
 
+  /* On n32 we can't access 64-bit registers via PTRACE_POKEUSR.  */
+  if (register_size (tdesc, regno) > sizeof (PTRACE_XFER_TYPE))
+    return 1;
+
   if (find_regno (tdesc, "r0") == regno)
     return 1;
 
@@ -242,6 +250,20 @@ mips_cannot_store_register (int regno)
   return 0;
 }
 
+static int
+mips_fetch_register (struct regcache *regcache, int regno)
+{
+  const struct target_desc *tdesc = current_process ()->tdesc;
+
+  if (find_regno (tdesc, "r0") == regno)
+    {
+      supply_register_zeroed (regcache, regno);
+      return 1;
+    }
+
+  return 0;
+}
+
 static CORE_ADDR
 mips_get_pc (struct regcache *regcache)
 {
@@ -418,7 +440,7 @@ static void
 mips_linux_prepare_to_resume (struct lwp_info *lwp)
 {
   ptid_t ptid = ptid_of (get_lwp_thread (lwp));
-  struct process_info *proc = find_process_pid (ptid_get_pid (ptid));
+  struct process_info *proc = find_process_pid (ptid.pid ());
   struct arch_process_info *priv = proc->priv->arch_private;
 
   if (lwp->arch_private->watch_registers_changed)
@@ -428,7 +450,7 @@ mips_linux_prepare_to_resume (struct lwp_info *lwp)
       if (mips_linux_watch_get_num_valid (&priv->watch_mirror) > 0)
        {
          /* Write the mirrored watch register values.  */
-         int tid = ptid_get_lwp (ptid);
+         int tid = ptid.lwp ();
 
          if (-1 == ptrace (PTRACE_SET_WATCH_REGS, tid,
                            &priv->watch_mirror, NULL))
@@ -655,8 +677,6 @@ ps_get_thread_area (struct ps_prochandle *ph,
   return PS_OK;
 }
 
-#ifdef HAVE_PTRACE_GETREGS
-
 static void
 mips_collect_register (struct regcache *regcache,
                       int use_64bit, int regno, union mips_register *reg)
@@ -689,6 +709,8 @@ mips_supply_register (struct regcache *regcache,
   supply_register (regcache, regno, reg->buf + offset);
 }
 
+#ifdef HAVE_PTRACE_GETREGS
+
 static void
 mips_collect_register_32bit (struct regcache *regcache,
                             int use_64bit, int regno, unsigned char *buf)
@@ -750,7 +772,9 @@ mips_store_gregset (struct regcache *regcache, const void *buf)
 
   use_64bit = (register_size (regcache->tdesc, 0) == 8);
 
-  for (i = 0; i < 32; i++)
+  supply_register_by_name_zeroed (regcache, "r0");
+
+  for (i = 1; i < 32; i++)
     mips_supply_register (regcache, use_64bit, i, regset + i);
 
   mips_supply_register (regcache, use_64bit,
@@ -822,6 +846,44 @@ mips_store_fpregset (struct regcache *regcache, const void *buf)
 }
 #endif /* HAVE_PTRACE_GETREGS */
 
+/* Take care of 32-bit registers with 64-bit ptrace, POKEUSER side.  */
+
+static void
+mips_collect_ptrace_register (struct regcache *regcache,
+                             int regno, char *buf)
+{
+  int use_64bit = sizeof (PTRACE_XFER_TYPE) == 8;
+
+  if (use_64bit && register_size (regcache->tdesc, regno) == 4)
+    {
+      union mips_register reg;
+
+      mips_collect_register (regcache, 0, regno, &reg);
+      memcpy (buf, &reg, sizeof (reg));
+    }
+  else
+    collect_register (regcache, regno, buf);
+}
+
+/* Take care of 32-bit registers with 64-bit ptrace, PEEKUSER side.  */
+
+static void
+mips_supply_ptrace_register (struct regcache *regcache,
+                            int regno, const char *buf)
+{
+  int use_64bit = sizeof (PTRACE_XFER_TYPE) == 8;
+
+  if (use_64bit && register_size (regcache->tdesc, regno) == 4)
+    {
+      union mips_register reg;
+
+      memcpy (&reg, buf, sizeof (reg));
+      mips_supply_register (regcache, 0, regno, &reg);
+    }
+  else
+    supply_register (regcache, regno, buf);
+}
+
 static struct regset_info mips_regsets[] = {
 #ifdef HAVE_PTRACE_GETREGS
   { PTRACE_GETREGS, PTRACE_SETREGS, 0, 38 * 8, GENERAL_REGS,
@@ -879,7 +941,7 @@ struct linux_target_ops the_low_target = {
   mips_regs_info,
   mips_cannot_fetch_register,
   mips_cannot_store_register,
-  NULL, /* fetch_register */
+  mips_fetch_register,
   mips_get_pc,
   mips_set_pc,
   NULL, /* breakpoint_kind_from_pc */
@@ -892,8 +954,8 @@ struct linux_target_ops the_low_target = {
   mips_remove_point,
   mips_stopped_by_watchpoint,
   mips_stopped_data_address,
-  NULL,
-  NULL,
+  mips_collect_ptrace_register,
+  mips_supply_ptrace_register,
   NULL, /* siginfo_fixup */
   mips_linux_new_process,
   mips_linux_delete_process,