* m68klinux-nat.c (IS_SIGTRAMP, IS_RT_SIGTRAMP)

	(m68k_linux_in_sigtramp, SIGCONTEXT_PC_OFFSET)
	(UCONTEXT_PC_OFFSET, m68k_linux_sigtramp_saved_pc)
	(m68k_linux_frame_saved_pc): Move to ...
	* m68klinux-tdep.c: ... here.  New file.
	* Makefile.in (m68klinux-tdep.o): Add dependencies.
	* config/m68k/linux.mt (TDEPFILES): Add m68klinux-tdep.o.

1 files changed, 124 insertions, 0 deletions

diff --git a/gdb/m68klinux-tdep.c b/gdb/m68klinux-tdep.c
new file mode 100644
index 00000000000..c4ae867f177
--- /dev/null
+++ b/gdb/m68klinux-tdep.c
@@ -0,0 +1,124 @@
+/* Motorola m68k target-dependent support for GNU/Linux.
+
+   Copyright 1996, 1998, 2000, 2001, 2002 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 2 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, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include "defs.h"
+#include "gdbcore.h"
+#include "frame.h"
+#include "target.h"
+
+
+/* Check whether insn1 and insn2 are parts of a signal trampoline.  */
+
+#define IS_SIGTRAMP(insn1, insn2)					\
+  (/* addaw #20,sp; moveq #119,d0; trap #0 */				\
+   (insn1 == 0xdefc0014 && insn2 == 0x70774e40)				\
+   /* moveq #119,d0; trap #0 */						\
+   || insn1 == 0x70774e40)
+
+#define IS_RT_SIGTRAMP(insn1, insn2)					\
+  (/* movel #173,d0; trap #0 */						\
+   (insn1 == 0x203c0000 && insn2 == 0x00ad4e40)				\
+   /* moveq #82,d0; notb d0; trap #0 */					\
+   || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40))
+
+/* Return non-zero if PC points into the signal trampoline.  For the sake
+   of m68k_linux_frame_saved_pc we also distinguish between non-RT and RT
+   signal trampolines.  */
+
+int
+m68k_linux_in_sigtramp (CORE_ADDR pc)
+{
+  CORE_ADDR sp;
+  char buf[12];
+  unsigned long insn0, insn1, insn2;
+
+  if (read_memory_nobpt (pc - 4, buf, sizeof (buf)))
+    return 0;
+  insn1 = extract_unsigned_integer (buf + 4, 4);
+  insn2 = extract_unsigned_integer (buf + 8, 4);
+  if (IS_SIGTRAMP (insn1, insn2))
+    return 1;
+  if (IS_RT_SIGTRAMP (insn1, insn2))
+    return 2;
+
+  insn0 = extract_unsigned_integer (buf, 4);
+  if (IS_SIGTRAMP (insn0, insn1))
+    return 1;
+  if (IS_RT_SIGTRAMP (insn0, insn1))
+    return 2;
+
+  insn0 = (insn0 << 16) | (insn1 >> 16);
+  insn1 = (insn1 << 16) | (insn2 >> 16);
+  if (IS_SIGTRAMP (insn0, insn1))
+    return 1;
+  if (IS_RT_SIGTRAMP (insn0, insn1))
+    return 2;
+
+  return 0;
+}
+
+/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>.  */
+#define SIGCONTEXT_PC_OFFSET 26
+
+/* Offset to saved PC in ucontext, from <asm/ucontext.h>.  */
+#define UCONTEXT_PC_OFFSET 88
+
+/* Get saved user PC for sigtramp from sigcontext or ucontext.  */
+
+static CORE_ADDR
+m68k_linux_sigtramp_saved_pc (struct frame_info *frame)
+{
+  CORE_ADDR sigcontext_addr;
+  char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
+  int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT;
+  int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;
+
+  /* Get sigcontext address, it is the third parameter on the stack.  */
+  if (frame->next)
+    sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next)
+					   + FRAME_ARGS_SKIP
+					   + sigcontext_offs,
+					   ptrbytes);
+  else
+    sigcontext_addr = read_memory_integer (read_register (SP_REGNUM)
+					   + sigcontext_offs,
+					   ptrbytes);
+
+  /* Don't cause a memory_error when accessing sigcontext in case the
+     stack layout has changed or the stack is corrupt.  */
+  if (m68k_linux_in_sigtramp (frame->pc) == 2)
+    target_read_memory (sigcontext_addr + UCONTEXT_PC_OFFSET, buf, ptrbytes);
+  else
+    target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
+  return extract_unsigned_integer (buf, ptrbytes);
+}
+
+/* Return the saved program counter for FRAME.  */
+
+CORE_ADDR
+m68k_linux_frame_saved_pc (struct frame_info *frame)
+{
+  if (get_frame_type (frame) == SIGTRAMP_FRAME)
+    return m68k_linux_sigtramp_saved_pc (frame);
+
+  return read_memory_integer (frame->frame + 4, 4);
+}