1 files changed, 435 insertions, 0 deletions
diff --git a/gdb/m68k-linux-tdep.c b/gdb/m68k-linux-tdep.c
new file mode 100644
index 00000000000..94fb953edf0
--- /dev/null
+++ b/gdb/m68k-linux-tdep.c
@@ -0,0 +1,435 @@
+/* Motorola m68k target-dependent support for GNU/Linux.
+
+   Copyright (C) 1996-2016 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 "defs.h"
+#include "gdbcore.h"
+#include "doublest.h"
+#include "floatformat.h"
+#include "frame.h"
+#include "target.h"
+#include "gdbtypes.h"
+#include "osabi.h"
+#include "regcache.h"
+#include "objfiles.h"
+#include "symtab.h"
+#include "m68k-tdep.h"
+#include "trad-frame.h"
+#include "frame-unwind.h"
+#include "glibc-tdep.h"
+#include "solib-svr4.h"
+#include "auxv.h"
+#include "observer.h"
+#include "elf/common.h"
+#include "linux-tdep.h"
+#include "regset.h"
+
+/* Offsets (in target ints) into jmp_buf.  */
+
+#define M68K_LINUX_JB_ELEMENT_SIZE 4
+#define M68K_LINUX_JB_PC 7
+
+/* 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 THIS_FRAME corresponds to a signal trampoline.  For
+   the sake of m68k_linux_get_sigtramp_info we also distinguish between
+   non-RT and RT signal trampolines.  */
+
+static int
+m68k_linux_pc_in_sigtramp (struct frame_info *this_frame)
+{
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);
+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+  gdb_byte buf[12];
+  unsigned long insn0, insn1, insn2;
+  CORE_ADDR pc = get_frame_pc (this_frame);
+
+  if (!safe_frame_unwind_memory (this_frame, pc - 4, buf, sizeof (buf)))
+    return 0;
+  insn1 = extract_unsigned_integer (buf + 4, 4, byte_order);
+  insn2 = extract_unsigned_integer (buf + 8, 4, byte_order);
+  if (IS_SIGTRAMP (insn1, insn2))
+    return 1;
+  if (IS_RT_SIGTRAMP (insn1, insn2))
+    return 2;
+
+  insn0 = extract_unsigned_integer (buf, 4, byte_order);
+  if (IS_SIGTRAMP (insn0, insn1))
+    return 1;
+  if (IS_RT_SIGTRAMP (insn0, insn1))
+    return 2;
+
+  insn0 = ((insn0 << 16) & 0xffffffff) | (insn1 >> 16);
+  insn1 = ((insn1 << 16) & 0xffffffff) | (insn2 >> 16);
+  if (IS_SIGTRAMP (insn0, insn1))
+    return 1;
+  if (IS_RT_SIGTRAMP (insn0, insn1))
+    return 2;
+
+  return 0;
+}
+
+/* From <asm/sigcontext.h>.  */
+static int m68k_linux_sigcontext_reg_offset[M68K_NUM_REGS] =
+{
+  2 * 4,			/* %d0 */
+  3 * 4,			/* %d1 */
+  -1,				/* %d2 */
+  -1,				/* %d3 */
+  -1,				/* %d4 */
+  -1,				/* %d5 */
+  -1,				/* %d6 */
+  -1,				/* %d7 */
+  4 * 4,			/* %a0 */
+  5 * 4,			/* %a1 */
+  -1,				/* %a2 */
+  -1,				/* %a3 */
+  -1,				/* %a4 */
+  -1,				/* %a5 */
+  -1,				/* %fp */
+  1 * 4,			/* %sp */
+  6 * 4,			/* %sr */
+  6 * 4 + 2,			/* %pc */
+  8 * 4,			/* %fp0 */
+  11 * 4,			/* %fp1 */
+  -1,				/* %fp2 */
+  -1,				/* %fp3 */
+  -1,				/* %fp4 */
+  -1,				/* %fp5 */
+  -1,				/* %fp6 */
+  -1,				/* %fp7 */
+  14 * 4,			/* %fpcr */
+  15 * 4,			/* %fpsr */
+  16 * 4			/* %fpiaddr */
+};
+
+static int m68k_uclinux_sigcontext_reg_offset[M68K_NUM_REGS] =
+{
+  2 * 4,			/* %d0 */
+  3 * 4,			/* %d1 */
+  -1,				/* %d2 */
+  -1,				/* %d3 */
+  -1,				/* %d4 */
+  -1,				/* %d5 */
+  -1,				/* %d6 */
+  -1,				/* %d7 */
+  4 * 4,			/* %a0 */
+  5 * 4,			/* %a1 */
+  -1,				/* %a2 */
+  -1,				/* %a3 */
+  -1,				/* %a4 */
+  6 * 4,			/* %a5 */
+  -1,				/* %fp */
+  1 * 4,			/* %sp */
+  7 * 4,			/* %sr */
+  7 * 4 + 2,			/* %pc */
+  -1,				/* %fp0 */
+  -1,				/* %fp1 */
+  -1,				/* %fp2 */
+  -1,				/* %fp3 */
+  -1,				/* %fp4 */
+  -1,				/* %fp5 */
+  -1,				/* %fp6 */
+  -1,				/* %fp7 */
+  -1,				/* %fpcr */
+  -1,				/* %fpsr */
+  -1				/* %fpiaddr */
+};
+
+/* From <asm/ucontext.h>.  */
+static int m68k_linux_ucontext_reg_offset[M68K_NUM_REGS] =
+{
+  6 * 4,			/* %d0 */
+  7 * 4,			/* %d1 */
+  8 * 4,			/* %d2 */
+  9 * 4,			/* %d3 */
+  10 * 4,			/* %d4 */
+  11 * 4,			/* %d5 */
+  12 * 4,			/* %d6 */
+  13 * 4,			/* %d7 */
+  14 * 4,			/* %a0 */
+  15 * 4,			/* %a1 */
+  16 * 4,			/* %a2 */
+  17 * 4,			/* %a3 */
+  18 * 4,			/* %a4 */
+  19 * 4,			/* %a5 */
+  20 * 4,			/* %fp */
+  21 * 4,			/* %sp */
+  23 * 4,			/* %sr */
+  22 * 4,			/* %pc */
+  27 * 4,			/* %fp0 */
+  30 * 4,			/* %fp1 */
+  33 * 4,			/* %fp2 */
+  36 * 4,			/* %fp3 */
+  39 * 4,			/* %fp4 */
+  42 * 4,			/* %fp5 */
+  45 * 4,			/* %fp6 */
+  48 * 4,			/* %fp7 */
+  24 * 4,			/* %fpcr */
+  25 * 4,			/* %fpsr */
+  26 * 4			/* %fpiaddr */
+};
+
+
+/* Get info about saved registers in sigtramp.  */
+
+struct m68k_linux_sigtramp_info
+{
+  /* Address of sigcontext.  */
+  CORE_ADDR sigcontext_addr;
+
+  /* Offset of registers in `struct sigcontext'.  */
+  int *sc_reg_offset;
+};
+
+/* Nonzero if running on uClinux.  */
+static int target_is_uclinux;
+
+static void
+m68k_linux_inferior_created (struct target_ops *objfile, int from_tty)
+{
+  /* Record that we will need to re-evaluate whether we are running on a
+     uClinux or normal GNU/Linux target (see m68k_linux_get_sigtramp_info).  */
+  target_is_uclinux = -1;
+}
+
+static struct m68k_linux_sigtramp_info
+m68k_linux_get_sigtramp_info (struct frame_info *this_frame)
+{
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);
+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+  CORE_ADDR sp;
+  struct m68k_linux_sigtramp_info info;
+
+  /* Determine whether we are running on a uClinux or normal GNU/Linux
+     target so we can use the correct sigcontext layouts.  */
+  if (target_is_uclinux == -1)
+    target_is_uclinux = linux_is_uclinux ();
+
+  sp = get_frame_register_unsigned (this_frame, M68K_SP_REGNUM);
+
+  /* Get sigcontext address, it is the third parameter on the stack.  */
+  info.sigcontext_addr = read_memory_unsigned_integer (sp + 8, 4, byte_order);
+
+  if (m68k_linux_pc_in_sigtramp (this_frame) == 2)
+    info.sc_reg_offset = m68k_linux_ucontext_reg_offset;
+  else
+    info.sc_reg_offset = (target_is_uclinux
+			  ? m68k_uclinux_sigcontext_reg_offset
+			  : m68k_linux_sigcontext_reg_offset);
+  return info;
+}
+
+/* Signal trampolines.  */
+
+static struct trad_frame_cache *
+m68k_linux_sigtramp_frame_cache (struct frame_info *this_frame,
+				 void **this_cache)
+{
+  struct frame_id this_id;
+  struct trad_frame_cache *cache;
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);
+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+  struct m68k_linux_sigtramp_info info;
+  gdb_byte buf[4];
+  int i;
+
+  if (*this_cache)
+    return (struct trad_frame_cache *) *this_cache;
+
+  cache = trad_frame_cache_zalloc (this_frame);
+
+  /* FIXME: cagney/2004-05-01: This is is long standing broken code.
+     The frame ID's code address should be the start-address of the
+     signal trampoline and not the current PC within that
+     trampoline.  */
+  get_frame_register (this_frame, M68K_SP_REGNUM, buf);
+  /* See the end of m68k_push_dummy_call.  */
+  this_id = frame_id_build (extract_unsigned_integer (buf, 4, byte_order)
+			    - 4 + 8, get_frame_pc (this_frame));
+  trad_frame_set_id (cache, this_id);
+
+  info = m68k_linux_get_sigtramp_info (this_frame);
+
+  for (i = 0; i < M68K_NUM_REGS; i++)
+    if (info.sc_reg_offset[i] != -1)
+      trad_frame_set_reg_addr (cache, i,
+			       info.sigcontext_addr + info.sc_reg_offset[i]);
+
+  *this_cache = cache;
+  return cache;
+}
+
+static void
+m68k_linux_sigtramp_frame_this_id (struct frame_info *this_frame,
+				   void **this_cache,
+				   struct frame_id *this_id)
+{
+  struct trad_frame_cache *cache =
+    m68k_linux_sigtramp_frame_cache (this_frame, this_cache);
+  trad_frame_get_id (cache, this_id);
+}
+
+static struct value *
+m68k_linux_sigtramp_frame_prev_register (struct frame_info *this_frame,
+					 void **this_cache,
+					 int regnum)
+{
+  /* Make sure we've initialized the cache.  */
+  struct trad_frame_cache *cache =
+    m68k_linux_sigtramp_frame_cache (this_frame, this_cache);
+  return trad_frame_get_register (cache, this_frame, regnum);
+}
+
+static int
+m68k_linux_sigtramp_frame_sniffer (const struct frame_unwind *self,
+				   struct frame_info *this_frame,
+				   void **this_prologue_cache)
+{
+  return m68k_linux_pc_in_sigtramp (this_frame);
+}
+
+static const struct frame_unwind m68k_linux_sigtramp_frame_unwind =
+{
+  SIGTRAMP_FRAME,
+  default_frame_unwind_stop_reason,
+  m68k_linux_sigtramp_frame_this_id,
+  m68k_linux_sigtramp_frame_prev_register,
+  NULL,
+  m68k_linux_sigtramp_frame_sniffer
+};
+
+/* Register maps for supply/collect regset functions.  */
+
+static const struct regcache_map_entry m68k_linux_gregmap[] =
+  {
+    { 7, M68K_D1_REGNUM, 4 },	/* d1 ... d7 */
+    { 7, M68K_A0_REGNUM, 4 },	/* a0 ... a6 */
+    { 1, M68K_D0_REGNUM, 4 },
+    { 1, M68K_SP_REGNUM, 4 },
+    { 1, REGCACHE_MAP_SKIP, 4 }, /* orig_d0 (skip) */
+    { 1, M68K_PS_REGNUM, 4 },
+    { 1, M68K_PC_REGNUM, 4 },
+    /* Ignore 16-bit fields 'fmtvec' and '__fill'.  */
+    { 0 }
+  };
+
+#define M68K_LINUX_GREGS_SIZE (20 * 4)
+
+static const struct regcache_map_entry m68k_linux_fpregmap[] =
+  {
+    { 8, M68K_FP0_REGNUM, 12 },	/* fp0 ... fp7 */
+    { 1, M68K_FPC_REGNUM, 4 },
+    { 1, M68K_FPS_REGNUM, 4 },
+    { 1, M68K_FPI_REGNUM, 4 },
+    { 0 }
+  };
+
+#define M68K_LINUX_FPREGS_SIZE (27 * 4)
+
+/* Register sets. */
+
+static const struct regset m68k_linux_gregset =
+  {
+    m68k_linux_gregmap,
+    regcache_supply_regset, regcache_collect_regset
+  };
+
+static const struct regset m68k_linux_fpregset =
+  {
+    m68k_linux_fpregmap,
+    regcache_supply_regset, regcache_collect_regset
+  };
+
+/* Iterate over core file register note sections.  */
+
+static void
+m68k_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
+					 iterate_over_regset_sections_cb *cb,
+					 void *cb_data,
+					 const struct regcache *regcache)
+{
+  cb (".reg", M68K_LINUX_GREGS_SIZE, &m68k_linux_gregset, NULL, cb_data);
+  cb (".reg2", M68K_LINUX_FPREGS_SIZE, &m68k_linux_fpregset, NULL, cb_data);
+}
+
+static void
+m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+  linux_init_abi (info, gdbarch);
+
+  tdep->jb_pc = M68K_LINUX_JB_PC;
+  tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE;
+
+  /* GNU/Linux uses a calling convention that's similar to SVR4.  It
+     returns integer values in %d0/%d1, pointer values in %a0 and
+     floating values in %fp0, just like SVR4, but uses %a1 to pass the
+     address to store a structure value.  It also returns small
+     structures in registers instead of memory.  */
+  m68k_svr4_init_abi (info, gdbarch);
+  tdep->struct_value_regnum = M68K_A1_REGNUM;
+  tdep->struct_return = reg_struct_return;
+
+  set_gdbarch_decr_pc_after_break (gdbarch, 2);
+
+  frame_unwind_append_unwinder (gdbarch, &m68k_linux_sigtramp_frame_unwind);
+
+  /* Shared library handling.  */
+
+  /* GNU/Linux uses SVR4-style shared libraries.  */
+  set_solib_svr4_fetch_link_map_offsets (gdbarch,
+					 svr4_ilp32_fetch_link_map_offsets);
+
+  /* GNU/Linux uses the dynamic linker included in the GNU C Library.  */
+  set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
+
+  set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
+
+  /* Core file support. */
+  set_gdbarch_iterate_over_regset_sections
+    (gdbarch, m68k_linux_iterate_over_regset_sections);
+
+  /* Enable TLS support.  */
+  set_gdbarch_fetch_tls_load_module_address (gdbarch,
+                                             svr4_fetch_objfile_link_map);
+}
+
+/* Provide a prototype to silence -Wmissing-prototypes.  */
+extern initialize_file_ftype _initialize_m68k_linux_tdep;
+
+void
+_initialize_m68k_linux_tdep (void)
+{
+  gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX,
+			  m68k_linux_init_abi);
+  observer_attach_inferior_created (m68k_linux_inferior_created);
+}