/* Motorola m68k target-dependent support for GNU/Linux. Copyright (C) 1996, 1998, 2000, 2001, 2002, 2003, 2004, 2007, 2008 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" /* 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) { CORE_ADDR sp; 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); 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) & 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) { 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); 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_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); 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) - 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, 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); 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); } 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); }