| /* Motorola m68k target-dependent support for GNU/Linux. |
| |
| Copyright (C) 1996, 1998, 2000-2004, 2007-2012 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 "gdb_string.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" |
| |
| /* 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; |
| |
| if (target_is_uclinux == -1) |
| { |
| /* Determine whether we are running on a uClinux or normal GNU/Linux |
| target so we can use the correct sigcontext layouts. */ |
| CORE_ADDR dummy; |
| |
| target_is_uclinux |
| = (target_auxv_search (¤t_target, AT_NULL, &dummy) > 0 |
| && target_auxv_search (¤t_target, AT_PAGESZ, &dummy) == 0); |
| } |
| |
| 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); |
| 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); |
| } |
| |
| 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 |
| }; |
| |
| 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); |
| |
| /* Enable TLS support. */ |
| set_gdbarch_fetch_tls_load_module_address (gdbarch, |
| svr4_fetch_objfile_link_map); |
| |
| set_gdbarch_get_siginfo_type (gdbarch, linux_get_siginfo_type); |
| } |
| |
| /* 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); |
| } |