| 1 | /* Native-dependent code for GNU/Linux on MIPS processors. |
| 2 | |
| 3 | Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007 |
| 4 | Free Software Foundation, 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., 51 Franklin Street, Fifth Floor, |
| 21 | Boston, MA 02110-1301, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "inferior.h" |
| 25 | #include "mips-tdep.h" |
| 26 | #include "target.h" |
| 27 | #include "linux-nat.h" |
| 28 | #include "mips-linux-tdep.h" |
| 29 | |
| 30 | #include "gdb_proc_service.h" |
| 31 | |
| 32 | #include <sys/ptrace.h> |
| 33 | |
| 34 | #ifndef PTRACE_GET_THREAD_AREA |
| 35 | #define PTRACE_GET_THREAD_AREA 25 |
| 36 | #endif |
| 37 | |
| 38 | /* Assume that we have PTRACE_GETREGS et al. support. If we do not, |
| 39 | we'll clear this and use PTRACE_PEEKUSER instead. */ |
| 40 | static int have_ptrace_regsets = 1; |
| 41 | |
| 42 | /* Saved function pointers to fetch and store a single register using |
| 43 | PTRACE_PEEKUSER and PTRACE_POKEUSER. */ |
| 44 | |
| 45 | void (*super_fetch_registers) (int); |
| 46 | void (*super_store_registers) (int); |
| 47 | |
| 48 | /* Pseudo registers can not be read. ptrace does not provide a way to |
| 49 | read (or set) MIPS_PS_REGNUM, and there's no point in reading or |
| 50 | setting MIPS_ZERO_REGNUM. We also can not set BADVADDR, CAUSE, or |
| 51 | FCRIR via ptrace(). */ |
| 52 | |
| 53 | int |
| 54 | mips_linux_cannot_fetch_register (int regno) |
| 55 | { |
| 56 | if (regno > MIPS_ZERO_REGNUM && regno < MIPS_ZERO_REGNUM + 32) |
| 57 | return 0; |
| 58 | else if (regno >= mips_regnum (current_gdbarch)->fp0 |
| 59 | && regno <= mips_regnum (current_gdbarch)->fp0 + 32) |
| 60 | return 0; |
| 61 | else if (regno == mips_regnum (current_gdbarch)->lo |
| 62 | || regno == mips_regnum (current_gdbarch)->hi |
| 63 | || regno == mips_regnum (current_gdbarch)->badvaddr |
| 64 | || regno == mips_regnum (current_gdbarch)->cause |
| 65 | || regno == mips_regnum (current_gdbarch)->pc |
| 66 | || regno == mips_regnum (current_gdbarch)->fp_control_status |
| 67 | || regno == mips_regnum (current_gdbarch)->fp_implementation_revision) |
| 68 | return 0; |
| 69 | else |
| 70 | return 1; |
| 71 | } |
| 72 | |
| 73 | int |
| 74 | mips_linux_cannot_store_register (int regno) |
| 75 | { |
| 76 | if (regno > MIPS_ZERO_REGNUM && regno < MIPS_ZERO_REGNUM + 32) |
| 77 | return 0; |
| 78 | else if (regno >= FP0_REGNUM && regno <= FP0_REGNUM + 32) |
| 79 | return 0; |
| 80 | else if (regno == mips_regnum (current_gdbarch)->lo |
| 81 | || regno == mips_regnum (current_gdbarch)->hi |
| 82 | || regno == mips_regnum (current_gdbarch)->pc |
| 83 | || regno == mips_regnum (current_gdbarch)->fp_control_status) |
| 84 | return 0; |
| 85 | else |
| 86 | return 1; |
| 87 | } |
| 88 | |
| 89 | /* Fetch the thread-local storage pointer for libthread_db. */ |
| 90 | |
| 91 | ps_err_e |
| 92 | ps_get_thread_area (const struct ps_prochandle *ph, |
| 93 | lwpid_t lwpid, int idx, void **base) |
| 94 | { |
| 95 | if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0) |
| 96 | return PS_ERR; |
| 97 | |
| 98 | /* IDX is the bias from the thread pointer to the beginning of the |
| 99 | thread descriptor. It has to be subtracted due to implementation |
| 100 | quirks in libthread_db. */ |
| 101 | *base = (void *) ((char *)*base - idx); |
| 102 | |
| 103 | return PS_OK; |
| 104 | } |
| 105 | |
| 106 | /* Fetch REGNO (or all registers if REGNO == -1) from the target |
| 107 | using PTRACE_GETREGS et al. */ |
| 108 | |
| 109 | static void |
| 110 | mips64_linux_regsets_fetch_registers (int regno) |
| 111 | { |
| 112 | int is_fp; |
| 113 | int tid; |
| 114 | |
| 115 | if (regno >= mips_regnum (current_gdbarch)->fp0 |
| 116 | && regno <= mips_regnum (current_gdbarch)->fp0 + 32) |
| 117 | is_fp = 1; |
| 118 | else if (regno == mips_regnum (current_gdbarch)->fp_control_status) |
| 119 | is_fp = 1; |
| 120 | else if (regno == mips_regnum (current_gdbarch)->fp_implementation_revision) |
| 121 | is_fp = 1; |
| 122 | else |
| 123 | is_fp = 0; |
| 124 | |
| 125 | tid = ptid_get_lwp (inferior_ptid); |
| 126 | if (tid == 0) |
| 127 | tid = ptid_get_pid (inferior_ptid); |
| 128 | |
| 129 | if (regno == -1 || !is_fp) |
| 130 | { |
| 131 | mips64_elf_gregset_t regs; |
| 132 | |
| 133 | if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) ®s) == -1) |
| 134 | { |
| 135 | if (errno == EIO) |
| 136 | { |
| 137 | have_ptrace_regsets = 0; |
| 138 | return; |
| 139 | } |
| 140 | perror_with_name (_("Couldn't get registers")); |
| 141 | } |
| 142 | |
| 143 | mips64_supply_gregset (®s); |
| 144 | } |
| 145 | |
| 146 | if (regno == -1 || is_fp) |
| 147 | { |
| 148 | mips64_elf_fpregset_t fp_regs; |
| 149 | |
| 150 | if (ptrace (PTRACE_GETFPREGS, tid, 0L, |
| 151 | (PTRACE_TYPE_ARG3) &fp_regs) == -1) |
| 152 | { |
| 153 | if (errno == EIO) |
| 154 | { |
| 155 | have_ptrace_regsets = 0; |
| 156 | return; |
| 157 | } |
| 158 | perror_with_name (_("Couldn't get FP registers")); |
| 159 | } |
| 160 | |
| 161 | mips64_supply_fpregset (&fp_regs); |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | /* Store REGNO (or all registers if REGNO == -1) to the target |
| 166 | using PTRACE_SETREGS et al. */ |
| 167 | |
| 168 | static void |
| 169 | mips64_linux_regsets_store_registers (int regno) |
| 170 | { |
| 171 | int is_fp; |
| 172 | int tid; |
| 173 | |
| 174 | if (regno >= mips_regnum (current_gdbarch)->fp0 |
| 175 | && regno <= mips_regnum (current_gdbarch)->fp0 + 32) |
| 176 | is_fp = 1; |
| 177 | else if (regno == mips_regnum (current_gdbarch)->fp_control_status) |
| 178 | is_fp = 1; |
| 179 | else if (regno == mips_regnum (current_gdbarch)->fp_implementation_revision) |
| 180 | is_fp = 1; |
| 181 | else |
| 182 | is_fp = 0; |
| 183 | |
| 184 | tid = ptid_get_lwp (inferior_ptid); |
| 185 | if (tid == 0) |
| 186 | tid = ptid_get_pid (inferior_ptid); |
| 187 | |
| 188 | if (regno == -1 || !is_fp) |
| 189 | { |
| 190 | mips64_elf_gregset_t regs; |
| 191 | |
| 192 | if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) ®s) == -1) |
| 193 | perror_with_name (_("Couldn't get registers")); |
| 194 | |
| 195 | mips64_fill_gregset (®s, regno); |
| 196 | |
| 197 | if (ptrace (PTRACE_SETREGS, tid, 0L, (PTRACE_TYPE_ARG3) ®s) == -1) |
| 198 | perror_with_name (_("Couldn't set registers")); |
| 199 | } |
| 200 | |
| 201 | if (regno == -1 || is_fp) |
| 202 | { |
| 203 | mips64_elf_fpregset_t fp_regs; |
| 204 | |
| 205 | if (ptrace (PTRACE_GETFPREGS, tid, 0L, |
| 206 | (PTRACE_TYPE_ARG3) &fp_regs) == -1) |
| 207 | perror_with_name (_("Couldn't get FP registers")); |
| 208 | |
| 209 | mips64_fill_fpregset (&fp_regs, regno); |
| 210 | |
| 211 | if (ptrace (PTRACE_SETFPREGS, tid, 0L, |
| 212 | (PTRACE_TYPE_ARG3) &fp_regs) == -1) |
| 213 | perror_with_name (_("Couldn't set FP registers")); |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | /* Fetch REGNO (or all registers if REGNO == -1) from the target |
| 218 | using any working method. */ |
| 219 | |
| 220 | static void |
| 221 | mips64_linux_fetch_registers (int regnum) |
| 222 | { |
| 223 | /* Unless we already know that PTRACE_GETREGS does not work, try it. */ |
| 224 | if (have_ptrace_regsets) |
| 225 | mips64_linux_regsets_fetch_registers (regnum); |
| 226 | |
| 227 | /* If we know, or just found out, that PTRACE_GETREGS does not work, fall |
| 228 | back to PTRACE_PEEKUSER. */ |
| 229 | if (!have_ptrace_regsets) |
| 230 | super_fetch_registers (regnum); |
| 231 | } |
| 232 | |
| 233 | /* Store REGNO (or all registers if REGNO == -1) to the target |
| 234 | using any working method. */ |
| 235 | |
| 236 | static void |
| 237 | mips64_linux_store_registers (int regnum) |
| 238 | { |
| 239 | /* Unless we already know that PTRACE_GETREGS does not work, try it. */ |
| 240 | if (have_ptrace_regsets) |
| 241 | mips64_linux_regsets_store_registers (regnum); |
| 242 | |
| 243 | /* If we know, or just found out, that PTRACE_GETREGS does not work, fall |
| 244 | back to PTRACE_PEEKUSER. */ |
| 245 | if (!have_ptrace_regsets) |
| 246 | super_store_registers (regnum); |
| 247 | } |
| 248 | |
| 249 | void _initialize_mips_linux_nat (void); |
| 250 | |
| 251 | void |
| 252 | _initialize_mips_linux_nat (void) |
| 253 | { |
| 254 | struct target_ops *t = linux_target (); |
| 255 | |
| 256 | super_fetch_registers = t->to_fetch_registers; |
| 257 | super_store_registers = t->to_store_registers; |
| 258 | |
| 259 | t->to_fetch_registers = mips64_linux_fetch_registers; |
| 260 | t->to_store_registers = mips64_linux_store_registers; |
| 261 | |
| 262 | linux_nat_add_target (t); |
| 263 | } |