GDB 7.6.50

gdb/common/mips-linux-watch.c

Index: gdb/common/mips-linux-watch.c
diff --git a/gdb/common/mips-linux-watch.c b/gdb/common/mips-linux-watch.c
new file mode 100644
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+++ b/gdb/common/mips-linux-watch.c
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+/* Copyright (C) 2009-2013 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <sys/ptrace.h>
+#include "mips-linux-watch.h"
+#include "gdb_assert.h"
+
+/* Assuming usable watch registers REGS, return the irw_mask of
+   register N.  */
+
+uint32_t
+mips_linux_watch_get_irw_mask (struct pt_watch_regs *regs, int n)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      return regs->mips32.watch_masks[n] & IRW_MASK;
+    case pt_watch_style_mips64:
+      return regs->mips64.watch_masks[n] & IRW_MASK;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, return the reg_mask of
+   register N.  */
+
+static uint32_t
+get_reg_mask (struct pt_watch_regs *regs, int n)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      return regs->mips32.watch_masks[n] & ~IRW_MASK;
+    case pt_watch_style_mips64:
+      return regs->mips64.watch_masks[n] & ~IRW_MASK;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, return the num_valid.  */
+
+uint32_t
+mips_linux_watch_get_num_valid (struct pt_watch_regs *regs)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      return regs->mips32.num_valid;
+    case pt_watch_style_mips64:
+      return regs->mips64.num_valid;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, return the watchlo of
+   register N.  */
+
+CORE_ADDR
+mips_linux_watch_get_watchlo (struct pt_watch_regs *regs, int n)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      return regs->mips32.watchlo[n];
+    case pt_watch_style_mips64:
+      return regs->mips64.watchlo[n];
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, set watchlo of register N to
+   VALUE.  */
+
+void
+mips_linux_watch_set_watchlo (struct pt_watch_regs *regs, int n,
+			      CORE_ADDR value)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      /*  The cast will never throw away bits as 64 bit addresses can
+	  never be used on a 32 bit kernel.  */
+      regs->mips32.watchlo[n] = (uint32_t) value;
+      break;
+    case pt_watch_style_mips64:
+      regs->mips64.watchlo[n] = value;
+      break;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, return the watchhi of
+   register N.  */
+
+uint32_t
+mips_linux_watch_get_watchhi (struct pt_watch_regs *regs, int n)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      return regs->mips32.watchhi[n];
+    case pt_watch_style_mips64:
+      return regs->mips64.watchhi[n];
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Assuming usable watch registers REGS, set watchhi of register N to
+   VALUE.  */
+
+void
+mips_linux_watch_set_watchhi (struct pt_watch_regs *regs, int n,
+			      uint16_t value)
+{
+  switch (regs->style)
+    {
+    case pt_watch_style_mips32:
+      regs->mips32.watchhi[n] = value;
+      break;
+    case pt_watch_style_mips64:
+      regs->mips64.watchhi[n] = value;
+      break;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      _("Unrecognized watch register style"));
+    }
+}
+
+/* Read the watch registers of process LWPID and store it in
+   WATCH_READBACK.  Save true to *WATCH_READBACK_VALID if watch
+   registers are valid.  Return 1 if watch registers are usable.
+   Cached information is used unless FORCE is true.  */
+
+int
+mips_linux_read_watch_registers (long lwpid,
+				 struct pt_watch_regs *watch_readback,
+				 int *watch_readback_valid, int force)
+{
+  if (force || *watch_readback_valid == 0)
+    {
+      if (ptrace (PTRACE_GET_WATCH_REGS, lwpid, watch_readback) == -1)
+	{
+	  *watch_readback_valid = -1;
+	  return 0;
+	}
+      switch (watch_readback->style)
+	{
+	case pt_watch_style_mips32:
+	  if (watch_readback->mips32.num_valid == 0)
+	    {
+	      *watch_readback_valid = -1;
+	      return 0;
+	    }
+	  break;
+	case pt_watch_style_mips64:
+	  if (watch_readback->mips64.num_valid == 0)
+	    {
+	      *watch_readback_valid = -1;
+	      return 0;
+	    }
+	  break;
+	default:
+	  *watch_readback_valid = -1;
+	  return 0;
+	}
+      /* Watch registers appear to be usable.  */
+      *watch_readback_valid = 1;
+    }
+  return (*watch_readback_valid == 1) ? 1 : 0;
+}
+
+/* Convert GDB's TYPE to an IRW mask.  */
+
+uint32_t
+mips_linux_watch_type_to_irw (int type)
+{
+  switch (type)
+    {
+    case hw_write:
+      return W_MASK;
+    case hw_read:
+      return R_MASK;
+    case hw_access:
+      return (W_MASK | R_MASK);
+    default:
+      return 0;
+    }
+}
+
+/* Set any low order bits in MASK that are not set.  */
+
+static CORE_ADDR
+fill_mask (CORE_ADDR mask)
+{
+  CORE_ADDR f = 1;
+
+  while (f && f < mask)
+    {
+      mask |= f;
+      f <<= 1;
+    }
+  return mask;
+}
+
+/* Try to add a single watch to the specified registers REGS.  The
+   address of added watch is ADDR, the length is LEN, and the mask
+   is IRW.  Return 1 on success, 0 on failure.  */
+
+int
+mips_linux_watch_try_one_watch (struct pt_watch_regs *regs,
+				CORE_ADDR addr, int len, uint32_t irw)
+{
+  CORE_ADDR base_addr, last_byte, break_addr, segment_len;
+  CORE_ADDR mask_bits, t_low;
+  uint16_t t_hi;
+  int i, free_watches;
+  struct pt_watch_regs regs_copy;
+
+  if (len <= 0)
+    return 0;
+
+  last_byte = addr + len - 1;
+  mask_bits = fill_mask (addr ^ last_byte) | IRW_MASK;
+  base_addr = addr & ~mask_bits;
+
+  /* Check to see if it is covered by current registers.  */
+  for (i = 0; i < mips_linux_watch_get_num_valid (regs); i++)
+    {
+      t_low = mips_linux_watch_get_watchlo (regs, i);
+      if (t_low != 0 && irw == ((uint32_t) t_low & irw))
+	{
+	  t_hi = mips_linux_watch_get_watchhi (regs, i) | IRW_MASK;
+	  t_low &= ~(CORE_ADDR) t_hi;
+	  if (addr >= t_low && last_byte <= (t_low + t_hi))
+	    return 1;
+	}
+    }
+  /* Try to find an empty register.  */
+  free_watches = 0;
+  for (i = 0; i < mips_linux_watch_get_num_valid (regs); i++)
+    {
+      t_low = mips_linux_watch_get_watchlo (regs, i);
+      if (t_low == 0
+	  && irw == (mips_linux_watch_get_irw_mask (regs, i) & irw))
+	{
+	  if (mask_bits <= (get_reg_mask (regs, i) | IRW_MASK))
+	    {
+	      /* It fits, we'll take it.  */
+	      mips_linux_watch_set_watchlo (regs, i, base_addr | irw);
+	      mips_linux_watch_set_watchhi (regs, i, mask_bits & ~IRW_MASK);
+	      return 1;
+	    }
+	  else
+	    {
+	      /* It doesn't fit, but has the proper IRW capabilities.  */
+	      free_watches++;
+	    }
+	}
+    }
+  if (free_watches > 1)
+    {
+      /* Try to split it across several registers.  */
+      regs_copy = *regs;
+      for (i = 0; i < mips_linux_watch_get_num_valid (&regs_copy); i++)
+	{
+	  t_low = mips_linux_watch_get_watchlo (&regs_copy, i);
+	  t_hi = get_reg_mask (&regs_copy, i) | IRW_MASK;
+	  if (t_low == 0 && irw == (t_hi & irw))
+	    {
+	      t_low = addr & ~(CORE_ADDR) t_hi;
+	      break_addr = t_low + t_hi + 1;
+	      if (break_addr >= addr + len)
+		segment_len = len;
+	      else
+		segment_len = break_addr - addr;
+	      mask_bits = fill_mask (addr ^ (addr + segment_len - 1));
+	      mips_linux_watch_set_watchlo (&regs_copy, i,
+					    (addr & ~mask_bits) | irw);
+	      mips_linux_watch_set_watchhi (&regs_copy, i,
+					    mask_bits & ~IRW_MASK);
+	      if (break_addr >= addr + len)
+		{
+		  *regs = regs_copy;
+		  return 1;
+		}
+	      len = addr + len - break_addr;
+	      addr = break_addr;
+	    }
+	}
+    }
+  /* It didn't fit anywhere, we failed.  */
+  return 0;
+}
+
+/* Fill in the watch registers REGS with the currently cached
+   watches CURRENT_WATCHES.  */
+
+void
+mips_linux_watch_populate_regs (struct mips_watchpoint *current_watches,
+				struct pt_watch_regs *regs)
+{
+  struct mips_watchpoint *w;
+  int i;
+
+  /* Clear them out.  */
+  for (i = 0; i < mips_linux_watch_get_num_valid (regs); i++)
+    {
+      mips_linux_watch_set_watchlo (regs, i, 0);
+      mips_linux_watch_set_watchhi (regs, i, 0);
+    }
+
+  w = current_watches;
+  while (w)
+    {
+      uint32_t irw = mips_linux_watch_type_to_irw (w->type);
+
+      i = mips_linux_watch_try_one_watch (regs, w->addr, w->len, irw);
+      /* They must all fit, because we previously calculated that they
+	 would.  */
+      gdb_assert (i);
+      w = w->next;
+    }
+}