| 1 | /* Native-dependent code for modern i386 BSD's. |
| 2 | |
| 3 | Copyright (C) 2000-2014 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "inferior.h" |
| 22 | #include "regcache.h" |
| 23 | |
| 24 | #include "gdb_assert.h" |
| 25 | #include <signal.h> |
| 26 | #include <stddef.h> |
| 27 | #include <sys/types.h> |
| 28 | #include <sys/ptrace.h> |
| 29 | #include <machine/reg.h> |
| 30 | #include <machine/frame.h> |
| 31 | |
| 32 | #include "i386-tdep.h" |
| 33 | #include "i387-tdep.h" |
| 34 | #include "i386bsd-nat.h" |
| 35 | #include "inf-ptrace.h" |
| 36 | \f |
| 37 | |
| 38 | /* In older BSD versions we cannot get at some of the segment |
| 39 | registers. FreeBSD for example didn't support the %fs and %gs |
| 40 | registers until the 3.0 release. We have autoconf checks for their |
| 41 | presence, and deal gracefully with their absence. */ |
| 42 | |
| 43 | /* Offset in `struct reg' where MEMBER is stored. */ |
| 44 | #define REG_OFFSET(member) offsetof (struct reg, member) |
| 45 | |
| 46 | /* At i386bsd_reg_offset[REGNUM] you'll find the offset in `struct |
| 47 | reg' where the GDB register REGNUM is stored. Unsupported |
| 48 | registers are marked with `-1'. */ |
| 49 | static int i386bsd_r_reg_offset[] = |
| 50 | { |
| 51 | REG_OFFSET (r_eax), |
| 52 | REG_OFFSET (r_ecx), |
| 53 | REG_OFFSET (r_edx), |
| 54 | REG_OFFSET (r_ebx), |
| 55 | REG_OFFSET (r_esp), |
| 56 | REG_OFFSET (r_ebp), |
| 57 | REG_OFFSET (r_esi), |
| 58 | REG_OFFSET (r_edi), |
| 59 | REG_OFFSET (r_eip), |
| 60 | REG_OFFSET (r_eflags), |
| 61 | REG_OFFSET (r_cs), |
| 62 | REG_OFFSET (r_ss), |
| 63 | REG_OFFSET (r_ds), |
| 64 | REG_OFFSET (r_es), |
| 65 | #ifdef HAVE_STRUCT_REG_R_FS |
| 66 | REG_OFFSET (r_fs), |
| 67 | #else |
| 68 | -1, |
| 69 | #endif |
| 70 | #ifdef HAVE_STRUCT_REG_R_GS |
| 71 | REG_OFFSET (r_gs) |
| 72 | #else |
| 73 | -1 |
| 74 | #endif |
| 75 | }; |
| 76 | |
| 77 | /* Macro to determine if a register is fetched with PT_GETREGS. */ |
| 78 | #define GETREGS_SUPPLIES(regnum) \ |
| 79 | ((0 <= (regnum) && (regnum) <= 15)) |
| 80 | |
| 81 | #ifdef HAVE_PT_GETXMMREGS |
| 82 | /* Set to 1 if the kernel supports PT_GETXMMREGS. Initialized to -1 |
| 83 | so that we try PT_GETXMMREGS the first time around. */ |
| 84 | static int have_ptrace_xmmregs = -1; |
| 85 | #endif |
| 86 | \f |
| 87 | |
| 88 | /* Supply the general-purpose registers in GREGS, to REGCACHE. */ |
| 89 | |
| 90 | static void |
| 91 | i386bsd_supply_gregset (struct regcache *regcache, const void *gregs) |
| 92 | { |
| 93 | const char *regs = gregs; |
| 94 | int regnum; |
| 95 | |
| 96 | for (regnum = 0; regnum < ARRAY_SIZE (i386bsd_r_reg_offset); regnum++) |
| 97 | { |
| 98 | int offset = i386bsd_r_reg_offset[regnum]; |
| 99 | |
| 100 | if (offset != -1) |
| 101 | regcache_raw_supply (regcache, regnum, regs + offset); |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | /* Collect register REGNUM from REGCACHE and store its contents in |
| 106 | GREGS. If REGNUM is -1, collect and store all appropriate |
| 107 | registers. */ |
| 108 | |
| 109 | static void |
| 110 | i386bsd_collect_gregset (const struct regcache *regcache, |
| 111 | void *gregs, int regnum) |
| 112 | { |
| 113 | char *regs = gregs; |
| 114 | int i; |
| 115 | |
| 116 | for (i = 0; i < ARRAY_SIZE (i386bsd_r_reg_offset); i++) |
| 117 | { |
| 118 | if (regnum == -1 || regnum == i) |
| 119 | { |
| 120 | int offset = i386bsd_r_reg_offset[i]; |
| 121 | |
| 122 | if (offset != -1) |
| 123 | regcache_raw_collect (regcache, i, regs + offset); |
| 124 | } |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this |
| 129 | for all registers (including the floating point registers). */ |
| 130 | |
| 131 | static void |
| 132 | i386bsd_fetch_inferior_registers (struct target_ops *ops, |
| 133 | struct regcache *regcache, int regnum) |
| 134 | { |
| 135 | if (regnum == -1 || GETREGS_SUPPLIES (regnum)) |
| 136 | { |
| 137 | struct reg regs; |
| 138 | |
| 139 | if (ptrace (PT_GETREGS, ptid_get_pid (inferior_ptid), |
| 140 | (PTRACE_TYPE_ARG3) ®s, 0) == -1) |
| 141 | perror_with_name (_("Couldn't get registers")); |
| 142 | |
| 143 | i386bsd_supply_gregset (regcache, ®s); |
| 144 | if (regnum != -1) |
| 145 | return; |
| 146 | } |
| 147 | |
| 148 | if (regnum == -1 || regnum >= I386_ST0_REGNUM) |
| 149 | { |
| 150 | struct fpreg fpregs; |
| 151 | #ifdef HAVE_PT_GETXMMREGS |
| 152 | char xmmregs[512]; |
| 153 | |
| 154 | if (have_ptrace_xmmregs != 0 |
| 155 | && ptrace(PT_GETXMMREGS, ptid_get_pid (inferior_ptid), |
| 156 | (PTRACE_TYPE_ARG3) xmmregs, 0) == 0) |
| 157 | { |
| 158 | have_ptrace_xmmregs = 1; |
| 159 | i387_supply_fxsave (regcache, -1, xmmregs); |
| 160 | } |
| 161 | else |
| 162 | { |
| 163 | if (ptrace (PT_GETFPREGS, ptid_get_pid (inferior_ptid), |
| 164 | (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) |
| 165 | perror_with_name (_("Couldn't get floating point status")); |
| 166 | |
| 167 | i387_supply_fsave (regcache, -1, &fpregs); |
| 168 | } |
| 169 | #else |
| 170 | if (ptrace (PT_GETFPREGS, ptid_get_pid (inferior_ptid), |
| 171 | (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) |
| 172 | perror_with_name (_("Couldn't get floating point status")); |
| 173 | |
| 174 | i387_supply_fsave (regcache, -1, &fpregs); |
| 175 | #endif |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | /* Store register REGNUM back into the inferior. If REGNUM is -1, do |
| 180 | this for all registers (including the floating point registers). */ |
| 181 | |
| 182 | static void |
| 183 | i386bsd_store_inferior_registers (struct target_ops *ops, |
| 184 | struct regcache *regcache, int regnum) |
| 185 | { |
| 186 | if (regnum == -1 || GETREGS_SUPPLIES (regnum)) |
| 187 | { |
| 188 | struct reg regs; |
| 189 | |
| 190 | if (ptrace (PT_GETREGS, ptid_get_pid (inferior_ptid), |
| 191 | (PTRACE_TYPE_ARG3) ®s, 0) == -1) |
| 192 | perror_with_name (_("Couldn't get registers")); |
| 193 | |
| 194 | i386bsd_collect_gregset (regcache, ®s, regnum); |
| 195 | |
| 196 | if (ptrace (PT_SETREGS, ptid_get_pid (inferior_ptid), |
| 197 | (PTRACE_TYPE_ARG3) ®s, 0) == -1) |
| 198 | perror_with_name (_("Couldn't write registers")); |
| 199 | |
| 200 | if (regnum != -1) |
| 201 | return; |
| 202 | } |
| 203 | |
| 204 | if (regnum == -1 || regnum >= I386_ST0_REGNUM) |
| 205 | { |
| 206 | struct fpreg fpregs; |
| 207 | #ifdef HAVE_PT_GETXMMREGS |
| 208 | char xmmregs[512]; |
| 209 | |
| 210 | if (have_ptrace_xmmregs != 0 |
| 211 | && ptrace(PT_GETXMMREGS, ptid_get_pid (inferior_ptid), |
| 212 | (PTRACE_TYPE_ARG3) xmmregs, 0) == 0) |
| 213 | { |
| 214 | have_ptrace_xmmregs = 1; |
| 215 | |
| 216 | i387_collect_fxsave (regcache, regnum, xmmregs); |
| 217 | |
| 218 | if (ptrace (PT_SETXMMREGS, ptid_get_pid (inferior_ptid), |
| 219 | (PTRACE_TYPE_ARG3) xmmregs, 0) == -1) |
| 220 | perror_with_name (_("Couldn't write XMM registers")); |
| 221 | } |
| 222 | else |
| 223 | { |
| 224 | have_ptrace_xmmregs = 0; |
| 225 | #endif |
| 226 | if (ptrace (PT_GETFPREGS, ptid_get_pid (inferior_ptid), |
| 227 | (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) |
| 228 | perror_with_name (_("Couldn't get floating point status")); |
| 229 | |
| 230 | i387_collect_fsave (regcache, regnum, &fpregs); |
| 231 | |
| 232 | if (ptrace (PT_SETFPREGS, ptid_get_pid (inferior_ptid), |
| 233 | (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) |
| 234 | perror_with_name (_("Couldn't write floating point status")); |
| 235 | #ifdef HAVE_PT_GETXMMREGS |
| 236 | } |
| 237 | #endif |
| 238 | } |
| 239 | } |
| 240 | |
| 241 | /* Create a prototype *BSD/i386 target. The client can override it |
| 242 | with local methods. */ |
| 243 | |
| 244 | struct target_ops * |
| 245 | i386bsd_target (void) |
| 246 | { |
| 247 | struct target_ops *t; |
| 248 | |
| 249 | t = inf_ptrace_target (); |
| 250 | t->to_fetch_registers = i386bsd_fetch_inferior_registers; |
| 251 | t->to_store_registers = i386bsd_store_inferior_registers; |
| 252 | return t; |
| 253 | } |
| 254 | \f |
| 255 | |
| 256 | /* Support for debug registers. */ |
| 257 | |
| 258 | #ifdef HAVE_PT_GETDBREGS |
| 259 | |
| 260 | /* Not all versions of FreeBSD/i386 that support the debug registers |
| 261 | have this macro. */ |
| 262 | #ifndef DBREG_DRX |
| 263 | #define DBREG_DRX(d, x) ((&d->dr0)[x]) |
| 264 | #endif |
| 265 | |
| 266 | static unsigned long |
| 267 | i386bsd_dr_get (ptid_t ptid, int regnum) |
| 268 | { |
| 269 | struct dbreg dbregs; |
| 270 | |
| 271 | if (ptrace (PT_GETDBREGS, ptid_get_pid (inferior_ptid), |
| 272 | (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) |
| 273 | perror_with_name (_("Couldn't read debug registers")); |
| 274 | |
| 275 | return DBREG_DRX ((&dbregs), regnum); |
| 276 | } |
| 277 | |
| 278 | static void |
| 279 | i386bsd_dr_set (int regnum, unsigned int value) |
| 280 | { |
| 281 | struct dbreg dbregs; |
| 282 | |
| 283 | if (ptrace (PT_GETDBREGS, ptid_get_pid (inferior_ptid), |
| 284 | (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) |
| 285 | perror_with_name (_("Couldn't get debug registers")); |
| 286 | |
| 287 | /* For some mysterious reason, some of the reserved bits in the |
| 288 | debug control register get set. Mask these off, otherwise the |
| 289 | ptrace call below will fail. */ |
| 290 | DBREG_DRX ((&dbregs), 7) &= ~(0x0000fc00); |
| 291 | |
| 292 | DBREG_DRX ((&dbregs), regnum) = value; |
| 293 | |
| 294 | if (ptrace (PT_SETDBREGS, ptid_get_pid (inferior_ptid), |
| 295 | (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) |
| 296 | perror_with_name (_("Couldn't write debug registers")); |
| 297 | } |
| 298 | |
| 299 | void |
| 300 | i386bsd_dr_set_control (unsigned long control) |
| 301 | { |
| 302 | i386bsd_dr_set (7, control); |
| 303 | } |
| 304 | |
| 305 | void |
| 306 | i386bsd_dr_set_addr (int regnum, CORE_ADDR addr) |
| 307 | { |
| 308 | gdb_assert (regnum >= 0 && regnum <= 4); |
| 309 | |
| 310 | i386bsd_dr_set (regnum, addr); |
| 311 | } |
| 312 | |
| 313 | CORE_ADDR |
| 314 | i386bsd_dr_get_addr (int regnum) |
| 315 | { |
| 316 | return i386bsd_dr_get (inferior_ptid, regnum); |
| 317 | } |
| 318 | |
| 319 | unsigned long |
| 320 | i386bsd_dr_get_status (void) |
| 321 | { |
| 322 | return i386bsd_dr_get (inferior_ptid, 6); |
| 323 | } |
| 324 | |
| 325 | unsigned long |
| 326 | i386bsd_dr_get_control (void) |
| 327 | { |
| 328 | return i386bsd_dr_get (inferior_ptid, 7); |
| 329 | } |
| 330 | |
| 331 | #endif /* PT_GETDBREGS */ |
| 332 | \f |
| 333 | |
| 334 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 335 | void _initialize_i386bsd_nat (void); |
| 336 | |
| 337 | void |
| 338 | _initialize_i386bsd_nat (void) |
| 339 | { |
| 340 | int offset; |
| 341 | |
| 342 | /* To support the recognition of signal handlers, i386bsd-tdep.c |
| 343 | hardcodes some constants. Inclusion of this file means that we |
| 344 | are compiling a native debugger, which means that we can use the |
| 345 | system header files and sysctl(3) to get at the relevant |
| 346 | information. */ |
| 347 | |
| 348 | #if defined (__FreeBSD_version) && __FreeBSD_version >= 400011 |
| 349 | #define SC_REG_OFFSET i386fbsd4_sc_reg_offset |
| 350 | #elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005 |
| 351 | #define SC_REG_OFFSET i386fbsd_sc_reg_offset |
| 352 | #elif defined (NetBSD) || defined (__NetBSD_Version__) |
| 353 | #define SC_REG_OFFSET i386nbsd_sc_reg_offset |
| 354 | #elif defined (OpenBSD) |
| 355 | #define SC_REG_OFFSET i386obsd_sc_reg_offset |
| 356 | #endif |
| 357 | |
| 358 | #ifdef SC_REG_OFFSET |
| 359 | |
| 360 | /* We only check the program counter, stack pointer and frame |
| 361 | pointer since these members of `struct sigcontext' are essential |
| 362 | for providing backtraces. More checks could be added, but would |
| 363 | involve adding configure checks for the appropriate structure |
| 364 | members, since older BSD's don't provide all of them. */ |
| 365 | |
| 366 | #define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM] |
| 367 | #define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM] |
| 368 | #define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM] |
| 369 | |
| 370 | /* Override the default value for the offset of the program counter |
| 371 | in the sigcontext structure. */ |
| 372 | offset = offsetof (struct sigcontext, sc_pc); |
| 373 | |
| 374 | if (SC_PC_OFFSET != offset) |
| 375 | { |
| 376 | warning (_("\ |
| 377 | offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\ |
| 378 | Please report this to <bug-gdb@gnu.org>."), |
| 379 | offset, SC_PC_OFFSET); |
| 380 | } |
| 381 | |
| 382 | SC_PC_OFFSET = offset; |
| 383 | |
| 384 | /* Likewise for the stack pointer. */ |
| 385 | offset = offsetof (struct sigcontext, sc_sp); |
| 386 | |
| 387 | if (SC_SP_OFFSET != offset) |
| 388 | { |
| 389 | warning (_("\ |
| 390 | offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\ |
| 391 | Please report this to <bug-gdb@gnu.org>."), |
| 392 | offset, SC_SP_OFFSET); |
| 393 | } |
| 394 | |
| 395 | SC_SP_OFFSET = offset; |
| 396 | |
| 397 | /* And the frame pointer. */ |
| 398 | offset = offsetof (struct sigcontext, sc_fp); |
| 399 | |
| 400 | if (SC_FP_OFFSET != offset) |
| 401 | { |
| 402 | warning (_("\ |
| 403 | offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\ |
| 404 | Please report this to <bug-gdb@gnu.org>."), |
| 405 | offset, SC_FP_OFFSET); |
| 406 | } |
| 407 | |
| 408 | SC_FP_OFFSET = offset; |
| 409 | |
| 410 | #endif /* SC_REG_OFFSET */ |
| 411 | } |