| /* Target-dependent code for NetBSD/i386. |
| |
| Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002, |
| 2003, 2004 |
| 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 "arch-utils.h" |
| #include "frame.h" |
| #include "gdbcore.h" |
| #include "regcache.h" |
| #include "regset.h" |
| #include "osabi.h" |
| #include "symtab.h" |
| |
| #include "gdb_assert.h" |
| #include "gdb_string.h" |
| |
| #include "i386-tdep.h" |
| #include "i387-tdep.h" |
| #include "nbsd-tdep.h" |
| #include "solib-svr4.h" |
| |
| /* From <machine/reg.h>. */ |
| static int i386nbsd_r_reg_offset[] = |
| { |
| 0 * 4, /* %eax */ |
| 1 * 4, /* %ecx */ |
| 2 * 4, /* %edx */ |
| 3 * 4, /* %ebx */ |
| 4 * 4, /* %esp */ |
| 5 * 4, /* %ebp */ |
| 6 * 4, /* %esi */ |
| 7 * 4, /* %edi */ |
| 8 * 4, /* %eip */ |
| 9 * 4, /* %eflags */ |
| 10 * 4, /* %cs */ |
| 11 * 4, /* %ss */ |
| 12 * 4, /* %ds */ |
| 13 * 4, /* %es */ |
| 14 * 4, /* %fs */ |
| 15 * 4 /* %gs */ |
| }; |
| |
| static void |
| i386nbsd_aout_supply_regset (const struct regset *regset, |
| struct regcache *regcache, int regnum, |
| const void *regs, size_t len) |
| { |
| const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); |
| |
| gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE); |
| |
| i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset); |
| i387_supply_fsave (regcache, regnum, (char *) regs + tdep->sizeof_gregset); |
| } |
| |
| static const struct regset * |
| i386nbsd_aout_regset_from_core_section (struct gdbarch *gdbarch, |
| const char *sect_name, |
| size_t sect_size) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| |
| /* NetBSD a.out core dumps don't use seperate register sets for the |
| general-purpose and floating-point registers. */ |
| |
| if (strcmp (sect_name, ".reg") == 0 |
| && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE) |
| { |
| if (tdep->gregset == NULL) |
| tdep->gregset = |
| regset_alloc (gdbarch, i386nbsd_aout_supply_regset, NULL); |
| return tdep->gregset; |
| } |
| |
| return NULL; |
| } |
| |
| /* Under NetBSD/i386, signal handler invocations can be identified by the |
| designated code sequence that is used to return from a signal handler. |
| In particular, the return address of a signal handler points to the |
| following code sequence: |
| |
| leal 0x10(%esp), %eax |
| pushl %eax |
| pushl %eax |
| movl $0x127, %eax # __sigreturn14 |
| int $0x80 |
| |
| Each instruction has a unique encoding, so we simply attempt to match |
| the instruction the PC is pointing to with any of the above instructions. |
| If there is a hit, we know the offset to the start of the designated |
| sequence and can then check whether we really are executing in the |
| signal trampoline. If not, -1 is returned, otherwise the offset from the |
| start of the return sequence is returned. */ |
| #define RETCODE_INSN1 0x8d |
| #define RETCODE_INSN2 0x50 |
| #define RETCODE_INSN3 0x50 |
| #define RETCODE_INSN4 0xb8 |
| #define RETCODE_INSN5 0xcd |
| |
| #define RETCODE_INSN2_OFF 4 |
| #define RETCODE_INSN3_OFF 5 |
| #define RETCODE_INSN4_OFF 6 |
| #define RETCODE_INSN5_OFF 11 |
| |
| static const unsigned char sigtramp_retcode[] = |
| { |
| RETCODE_INSN1, 0x44, 0x24, 0x10, |
| RETCODE_INSN2, |
| RETCODE_INSN3, |
| RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00, |
| RETCODE_INSN5, 0x80, |
| }; |
| |
| static LONGEST |
| i386nbsd_sigtramp_offset (struct frame_info *next_frame) |
| { |
| CORE_ADDR pc = frame_pc_unwind (next_frame); |
| unsigned char ret[sizeof(sigtramp_retcode)], insn; |
| LONGEST off; |
| int i; |
| |
| if (!safe_frame_unwind_memory (next_frame, pc, &insn, 1)) |
| return -1; |
| |
| switch (insn) |
| { |
| case RETCODE_INSN1: |
| off = 0; |
| break; |
| |
| case RETCODE_INSN2: |
| /* INSN2 and INSN3 are the same. Read at the location of PC+1 |
| to determine if we're actually looking at INSN2 or INSN3. */ |
| if (!safe_frame_unwind_memory (next_frame, pc + 1, &insn, 1)) |
| return -1; |
| |
| if (insn == RETCODE_INSN3) |
| off = RETCODE_INSN2_OFF; |
| else |
| off = RETCODE_INSN3_OFF; |
| break; |
| |
| case RETCODE_INSN4: |
| off = RETCODE_INSN4_OFF; |
| break; |
| |
| case RETCODE_INSN5: |
| off = RETCODE_INSN5_OFF; |
| break; |
| |
| default: |
| return -1; |
| } |
| |
| pc -= off; |
| |
| if (!safe_frame_unwind_memory (next_frame, pc, ret, sizeof (ret))) |
| return -1; |
| |
| if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0) |
| return off; |
| |
| return -1; |
| } |
| |
| /* Return whether the frame preceding NEXT_FRAME corresponds to a |
| NetBSD sigtramp routine. */ |
| |
| static int |
| i386nbsd_sigtramp_p (struct frame_info *next_frame) |
| { |
| CORE_ADDR pc = frame_pc_unwind (next_frame); |
| char *name; |
| |
| find_pc_partial_function (pc, &name, NULL, NULL); |
| return (nbsd_pc_in_sigtramp (pc, name) |
| || i386nbsd_sigtramp_offset (next_frame) >= 0); |
| } |
| |
| /* From <machine/signal.h>. */ |
| int i386nbsd_sc_reg_offset[] = |
| { |
| 10 * 4, /* %eax */ |
| 9 * 4, /* %ecx */ |
| 8 * 4, /* %edx */ |
| 7 * 4, /* %ebx */ |
| 14 * 4, /* %esp */ |
| 6 * 4, /* %ebp */ |
| 5 * 4, /* %esi */ |
| 4 * 4, /* %edi */ |
| 11 * 4, /* %eip */ |
| 13 * 4, /* %eflags */ |
| 12 * 4, /* %cs */ |
| 15 * 4, /* %ss */ |
| 3 * 4, /* %ds */ |
| 2 * 4, /* %es */ |
| 1 * 4, /* %fs */ |
| 0 * 4 /* %gs */ |
| }; |
| |
| static void |
| i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| |
| /* Obviously NetBSD is BSD-based. */ |
| i386bsd_init_abi (info, gdbarch); |
| |
| /* NetBSD has a different `struct reg'. */ |
| tdep->gregset_reg_offset = i386nbsd_r_reg_offset; |
| tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset); |
| tdep->sizeof_gregset = 16 * 4; |
| |
| /* NetBSD has different signal trampoline conventions. */ |
| tdep->sigtramp_start = 0; |
| tdep->sigtramp_end = 0; |
| tdep->sigtramp_p = i386nbsd_sigtramp_p; |
| |
| /* NetBSD uses -freg-struct-return by default. */ |
| tdep->struct_return = reg_struct_return; |
| |
| /* NetBSD has a `struct sigcontext' that's different from the |
| original 4.3 BSD. */ |
| tdep->sc_reg_offset = i386nbsd_sc_reg_offset; |
| tdep->sc_num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset); |
| } |
| |
| /* NetBSD a.out. */ |
| |
| static void |
| i386nbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| { |
| i386nbsd_init_abi (info, gdbarch); |
| |
| /* NetBSD a.out has a single register set. */ |
| set_gdbarch_regset_from_core_section |
| (gdbarch, i386nbsd_aout_regset_from_core_section); |
| } |
| |
| /* NetBSD ELF. */ |
| |
| static void |
| i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| |
| /* It's still NetBSD. */ |
| i386nbsd_init_abi (info, gdbarch); |
| |
| /* But ELF-based. */ |
| i386_elf_init_abi (info, gdbarch); |
| |
| /* NetBSD ELF uses SVR4-style shared libraries. */ |
| set_gdbarch_in_solib_call_trampoline |
| (gdbarch, generic_in_solib_call_trampoline); |
| set_solib_svr4_fetch_link_map_offsets |
| (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
| |
| /* NetBSD ELF uses -fpcc-struct-return by default. */ |
| tdep->struct_return = pcc_struct_return; |
| } |
| |
| void |
| _initialize_i386nbsd_tdep (void) |
| { |
| gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT, |
| i386nbsdaout_init_abi); |
| gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF, |
| i386nbsdelf_init_abi); |
| } |