/* Motorola m68k target-dependent support for GNU/Linux.
- Copyright 1996, 1998, 2000, 2001, 2002 Free Software Foundation,
- Inc.
+ Copyright (C) 1996-2015 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
+ 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,
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. */
+ 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"
\f
+/* 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) \
/* 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. */
+/* 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. */
-int
-m68k_linux_in_sigtramp (CORE_ADDR pc)
+static int
+m68k_linux_pc_in_sigtramp (struct frame_info *this_frame)
{
- CORE_ADDR sp;
- char buf[12];
+ 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 (read_memory_nobpt (pc - 4, buf, sizeof (buf)))
+ if (!safe_frame_unwind_memory (this_frame, pc - 4, buf, sizeof (buf)))
return 0;
- insn1 = extract_unsigned_integer (buf + 4, 4);
- insn2 = extract_unsigned_integer (buf + 8, 4);
+ 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);
+ 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) | (insn1 >> 16);
- insn1 = (insn1 << 16) | (insn2 >> 16);
+ 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 0;
}
-/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
-#define SIGCONTEXT_PC_OFFSET 26
+/* 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 */
+};
-/* 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. */
+/* Get info about saved registers in sigtramp. */
-static CORE_ADDR
-m68k_linux_sigtramp_saved_pc (struct frame_info *frame)
+struct m68k_linux_sigtramp_info
{
+ /* Address of sigcontext. */
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;
+
+ /* 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. */
- 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);
+ 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
- target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
- return extract_unsigned_integer (buf, ptrbytes);
+ info.sc_reg_offset = (target_is_uclinux
+ ? m68k_uclinux_sigcontext_reg_offset
+ : m68k_linux_sigcontext_reg_offset);
+ return info;
}
-/* Return the saved program counter for FRAME. */
+/* Signal trampolines. */
-CORE_ADDR
-m68k_linux_frame_saved_pc (struct frame_info *frame)
+static struct trad_frame_cache *
+m68k_linux_sigtramp_frame_cache (struct frame_info *this_frame,
+ void **this_cache)
{
- if (get_frame_type (frame) == SIGTRAMP_FRAME)
- return m68k_linux_sigtramp_saved_pc (frame);
+ struct frame_id this_id;
+ struct trad_frame_cache *cache;
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ 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 *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);
+}
- return read_memory_integer (frame->frame + 4, 4);
+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);
}