| 1 | /* Target-dependent code for NetBSD/Alpha. |
| 2 | |
| 3 | Copyright 2002, 2003, 2004 Free Software Foundation, Inc. |
| 4 | Contributed by Wasabi Systems, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 2 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 21 | Boston, MA 02111-1307, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "gdbcore.h" |
| 25 | #include "frame.h" |
| 26 | #include "regcache.h" |
| 27 | #include "value.h" |
| 28 | #include "osabi.h" |
| 29 | |
| 30 | #include "gdb_string.h" |
| 31 | |
| 32 | #include "alpha-tdep.h" |
| 33 | #include "alphabsd-tdep.h" |
| 34 | #include "nbsd-tdep.h" |
| 35 | #include "solib-svr4.h" |
| 36 | |
| 37 | static void |
| 38 | fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which, |
| 39 | CORE_ADDR ignore) |
| 40 | { |
| 41 | char *regs, *fpregs; |
| 42 | int regno; |
| 43 | |
| 44 | /* Table to map a gdb register number to a trapframe register index. */ |
| 45 | static const int regmap[] = |
| 46 | { |
| 47 | 0, 1, 2, 3, |
| 48 | 4, 5, 6, 7, |
| 49 | 8, 9, 10, 11, |
| 50 | 12, 13, 14, 15, |
| 51 | 30, 31, 32, 16, |
| 52 | 17, 18, 19, 20, |
| 53 | 21, 22, 23, 24, |
| 54 | 25, 29, 26 |
| 55 | }; |
| 56 | #define SIZEOF_TRAPFRAME (33 * 8) |
| 57 | |
| 58 | /* We get everything from one section. */ |
| 59 | if (which != 0) |
| 60 | return; |
| 61 | |
| 62 | regs = core_reg_sect; |
| 63 | fpregs = core_reg_sect + SIZEOF_TRAPFRAME; |
| 64 | |
| 65 | if (core_reg_size < (SIZEOF_TRAPFRAME + SIZEOF_STRUCT_FPREG)) |
| 66 | { |
| 67 | warning (_("Wrong size register set in core file.")); |
| 68 | return; |
| 69 | } |
| 70 | |
| 71 | /* Integer registers. */ |
| 72 | for (regno = 0; regno < ALPHA_ZERO_REGNUM; regno++) |
| 73 | regcache_raw_supply (current_regcache, regno, regs + (regmap[regno] * 8)); |
| 74 | regcache_raw_supply (current_regcache, ALPHA_ZERO_REGNUM, NULL); |
| 75 | regcache_raw_supply (current_regcache, PC_REGNUM, regs + (28 * 8)); |
| 76 | |
| 77 | /* Floating point registers. */ |
| 78 | alphabsd_supply_fpreg (fpregs, -1); |
| 79 | } |
| 80 | |
| 81 | static void |
| 82 | fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size, int which, |
| 83 | CORE_ADDR ignore) |
| 84 | { |
| 85 | switch (which) |
| 86 | { |
| 87 | case 0: /* Integer registers. */ |
| 88 | if (core_reg_size != SIZEOF_STRUCT_REG) |
| 89 | warning (_("Wrong size register set in core file.")); |
| 90 | else |
| 91 | alphabsd_supply_reg (core_reg_sect, -1); |
| 92 | break; |
| 93 | |
| 94 | case 2: /* Floating point registers. */ |
| 95 | if (core_reg_size != SIZEOF_STRUCT_FPREG) |
| 96 | warning (_("Wrong size FP register set in core file.")); |
| 97 | else |
| 98 | alphabsd_supply_fpreg (core_reg_sect, -1); |
| 99 | break; |
| 100 | |
| 101 | default: |
| 102 | /* Don't know what kind of register request this is; just ignore it. */ |
| 103 | break; |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | static struct core_fns alphanbsd_core_fns = |
| 108 | { |
| 109 | bfd_target_unknown_flavour, /* core_flavour */ |
| 110 | default_check_format, /* check_format */ |
| 111 | default_core_sniffer, /* core_sniffer */ |
| 112 | fetch_core_registers, /* core_read_registers */ |
| 113 | NULL /* next */ |
| 114 | }; |
| 115 | |
| 116 | static struct core_fns alphanbsd_elfcore_fns = |
| 117 | { |
| 118 | bfd_target_elf_flavour, /* core_flavour */ |
| 119 | default_check_format, /* check_format */ |
| 120 | default_core_sniffer, /* core_sniffer */ |
| 121 | fetch_elfcore_registers, /* core_read_registers */ |
| 122 | NULL /* next */ |
| 123 | }; |
| 124 | |
| 125 | /* Under NetBSD/alpha, signal handler invocations can be identified by the |
| 126 | designated code sequence that is used to return from a signal handler. |
| 127 | In particular, the return address of a signal handler points to the |
| 128 | following code sequence: |
| 129 | |
| 130 | ldq a0, 0(sp) |
| 131 | lda sp, 16(sp) |
| 132 | lda v0, 295(zero) # __sigreturn14 |
| 133 | call_pal callsys |
| 134 | |
| 135 | Each instruction has a unique encoding, so we simply attempt to match |
| 136 | the instruction the PC is pointing to with any of the above instructions. |
| 137 | If there is a hit, we know the offset to the start of the designated |
| 138 | sequence and can then check whether we really are executing in the |
| 139 | signal trampoline. If not, -1 is returned, otherwise the offset from the |
| 140 | start of the return sequence is returned. */ |
| 141 | static const unsigned char sigtramp_retcode[] = |
| 142 | { |
| 143 | 0x00, 0x00, 0x1e, 0xa6, /* ldq a0, 0(sp) */ |
| 144 | 0x10, 0x00, 0xde, 0x23, /* lda sp, 16(sp) */ |
| 145 | 0x27, 0x01, 0x1f, 0x20, /* lda v0, 295(zero) */ |
| 146 | 0x83, 0x00, 0x00, 0x00, /* call_pal callsys */ |
| 147 | }; |
| 148 | #define RETCODE_NWORDS 4 |
| 149 | #define RETCODE_SIZE (RETCODE_NWORDS * 4) |
| 150 | |
| 151 | LONGEST |
| 152 | alphanbsd_sigtramp_offset (CORE_ADDR pc) |
| 153 | { |
| 154 | unsigned char ret[RETCODE_SIZE], w[4]; |
| 155 | LONGEST off; |
| 156 | int i; |
| 157 | |
| 158 | if (deprecated_read_memory_nobpt (pc, (char *) w, 4) != 0) |
| 159 | return -1; |
| 160 | |
| 161 | for (i = 0; i < RETCODE_NWORDS; i++) |
| 162 | { |
| 163 | if (memcmp (w, sigtramp_retcode + (i * 4), 4) == 0) |
| 164 | break; |
| 165 | } |
| 166 | if (i == RETCODE_NWORDS) |
| 167 | return (-1); |
| 168 | |
| 169 | off = i * 4; |
| 170 | pc -= off; |
| 171 | |
| 172 | if (deprecated_read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0) |
| 173 | return -1; |
| 174 | |
| 175 | if (memcmp (ret, sigtramp_retcode, RETCODE_SIZE) == 0) |
| 176 | return off; |
| 177 | |
| 178 | return -1; |
| 179 | } |
| 180 | |
| 181 | static int |
| 182 | alphanbsd_pc_in_sigtramp (CORE_ADDR pc, char *func_name) |
| 183 | { |
| 184 | return (nbsd_pc_in_sigtramp (pc, func_name) |
| 185 | || alphanbsd_sigtramp_offset (pc) >= 0); |
| 186 | } |
| 187 | |
| 188 | static CORE_ADDR |
| 189 | alphanbsd_sigcontext_addr (struct frame_info *frame) |
| 190 | { |
| 191 | /* FIXME: This is not correct for all versions of NetBSD/alpha. |
| 192 | We will probably need to disassemble the trampoline to figure |
| 193 | out which trampoline frame type we have. */ |
| 194 | return get_frame_base (frame); |
| 195 | } |
| 196 | |
| 197 | static void |
| 198 | alphanbsd_init_abi (struct gdbarch_info info, |
| 199 | struct gdbarch *gdbarch) |
| 200 | { |
| 201 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 202 | |
| 203 | /* Hook into the DWARF CFI frame unwinder. */ |
| 204 | alpha_dwarf2_init_abi (info, gdbarch); |
| 205 | |
| 206 | /* Hook into the MDEBUG frame unwinder. */ |
| 207 | alpha_mdebug_init_abi (info, gdbarch); |
| 208 | |
| 209 | /* NetBSD/alpha does not provide single step support via ptrace(2); we |
| 210 | must use software single-stepping. */ |
| 211 | set_gdbarch_software_single_step (gdbarch, alpha_software_single_step); |
| 212 | |
| 213 | set_solib_svr4_fetch_link_map_offsets (gdbarch, |
| 214 | nbsd_lp64_solib_svr4_fetch_link_map_offsets); |
| 215 | |
| 216 | tdep->dynamic_sigtramp_offset = alphanbsd_sigtramp_offset; |
| 217 | tdep->pc_in_sigtramp = alphanbsd_pc_in_sigtramp; |
| 218 | tdep->sigcontext_addr = alphanbsd_sigcontext_addr; |
| 219 | |
| 220 | tdep->jb_pc = 2; |
| 221 | tdep->jb_elt_size = 8; |
| 222 | } |
| 223 | |
| 224 | void |
| 225 | _initialize_alphanbsd_tdep (void) |
| 226 | { |
| 227 | gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_NETBSD_ELF, |
| 228 | alphanbsd_init_abi); |
| 229 | gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_OPENBSD_ELF, |
| 230 | alphanbsd_init_abi); |
| 231 | |
| 232 | deprecated_add_core_fns (&alphanbsd_core_fns); |
| 233 | deprecated_add_core_fns (&alphanbsd_elfcore_fns); |
| 234 | } |