| /* Target-dependent code for NetBSD/i386, for GDB. |
| Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002 |
| 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 "gdbtypes.h" |
| #include "gdbcore.h" |
| #include "regcache.h" |
| #include "arch-utils.h" |
| |
| #include "i386-tdep.h" |
| #include "i387-tdep.h" |
| #include "nbsd-tdep.h" |
| |
| #include "solib-svr4.h" |
| |
| /* Map a GDB register number to an offset in the reg structure. */ |
| static int regmap[] = |
| { |
| ( 0 * 4), /* %eax */ |
| ( 1 * 4), /* %ecx */ |
| ( 2 * 4), /* %edx */ |
| ( 3 * 4), /* %ebx */ |
| ( 4 * 4), /* %esp */ |
| ( 5 * 4), /* %epb */ |
| ( 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 */ |
| }; |
| |
| #define SIZEOF_STRUCT_REG (16 * 4) |
| |
| static void |
| i386nbsd_supply_reg (char *regs, int regno) |
| { |
| int i; |
| |
| for (i = 0; i <= 15; i++) |
| if (regno == i || regno == -1) |
| supply_register (i, regs + regmap[i]); |
| } |
| |
| static void |
| fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which, |
| CORE_ADDR ignore) |
| { |
| char *regs, *fsave; |
| |
| /* We get everything from one section. */ |
| if (which != 0) |
| return; |
| |
| if (core_reg_size < (SIZEOF_STRUCT_REG + 108)) |
| { |
| warning ("Wrong size register set in core file."); |
| return; |
| } |
| |
| regs = core_reg_sect; |
| fsave = core_reg_sect + SIZEOF_STRUCT_REG; |
| |
| /* Integer registers. */ |
| i386nbsd_supply_reg (regs, -1); |
| |
| /* Floating point registers. */ |
| i387_supply_fsave (fsave); |
| } |
| |
| static void |
| fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size, |
| int which, CORE_ADDR ignore) |
| { |
| switch (which) |
| { |
| case 0: /* Integer registers. */ |
| if (core_reg_size != SIZEOF_STRUCT_REG) |
| warning ("Wrong size register set in core file."); |
| else |
| i386nbsd_supply_reg (core_reg_sect, -1); |
| break; |
| |
| case 2: /* Floating point registers. */ |
| if (core_reg_size != 108) |
| warning ("Wrong size FP register set in core file."); |
| else |
| i387_supply_fsave (core_reg_sect); |
| break; |
| |
| case 3: /* "Extended" floating point registers. This is gdb-speak |
| for SSE/SSE2. */ |
| if (core_reg_size != 512) |
| warning ("Wrong size XMM register set in core file."); |
| else |
| i387_supply_fxsave (core_reg_sect); |
| break; |
| |
| default: |
| /* Don't know what kind of register request this is; just ignore it. */ |
| break; |
| } |
| } |
| |
| static struct core_fns i386nbsd_core_fns = |
| { |
| bfd_target_unknown_flavour, /* core_flavour */ |
| default_check_format, /* check_format */ |
| default_core_sniffer, /* core_sniffer */ |
| fetch_core_registers, /* core_read_registers */ |
| NULL /* next */ |
| }; |
| |
| static struct core_fns i386nbsd_elfcore_fns = |
| { |
| bfd_target_elf_flavour, /* core_flavour */ |
| default_check_format, /* check_format */ |
| default_core_sniffer, /* core_sniffer */ |
| fetch_elfcore_registers, /* core_read_registers */ |
| NULL /* next */ |
| }; |
| |
| /* 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 (CORE_ADDR pc) |
| { |
| unsigned char ret[sizeof(sigtramp_retcode)], insn; |
| LONGEST off; |
| int i; |
| |
| if (read_memory_nobpt (pc, &insn, 1) != 0) |
| 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 (read_memory_nobpt (pc + 1, &insn, 1) != 0) |
| 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 (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0) |
| return -1; |
| |
| if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0) |
| return off; |
| |
| return -1; |
| } |
| |
| static int |
| i386nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name) |
| { |
| return (nbsd_pc_in_sigtramp (pc, name) |
| || i386nbsd_sigtramp_offset (pc) >= 0); |
| } |
| |
| /* From <machine/signal.h>. */ |
| int i386nbsd_sc_pc_offset = 44; |
| int i386nbsd_sc_sp_offset = 56; |
| |
| 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 different signal trampoline conventions. */ |
| set_gdbarch_pc_in_sigtramp (gdbarch, i386nbsd_pc_in_sigtramp); |
| /* FIXME: kettenis/20020906: We should probably provide |
| NetBSD-specific versions of these functions if we want to |
| recognize signal trampolines that live on the stack. */ |
| set_gdbarch_sigtramp_start (gdbarch, NULL); |
| set_gdbarch_sigtramp_end (gdbarch, NULL); |
| |
| /* NetBSD uses -freg-struct-return by default. */ |
| tdep->struct_return = reg_struct_return; |
| |
| /* NetBSD has a `struct sigcontext' that's different from the |
| origional 4.3 BSD. */ |
| tdep->sc_pc_offset = i386nbsd_sc_pc_offset; |
| tdep->sc_sp_offset = i386nbsd_sc_sp_offset; |
| } |
| |
| /* 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, |
| nbsd_ilp32_solib_svr4_fetch_link_map_offsets); |
| |
| /* NetBSD ELF uses -fpcc-struct-return by default. */ |
| tdep->struct_return = pcc_struct_return; |
| |
| /* We support the SSE registers on NetBSD ELF. */ |
| tdep->num_xmm_regs = I386_NUM_XREGS - 1; |
| set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS |
| + I386_NUM_XREGS); |
| } |
| |
| void |
| _initialize_i386nbsd_tdep (void) |
| { |
| add_core_fns (&i386nbsd_core_fns); |
| add_core_fns (&i386nbsd_elfcore_fns); |
| |
| gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_AOUT, |
| i386nbsd_init_abi); |
| gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_ELF, |
| i386nbsdelf_init_abi); |
| } |