| 1 | /* Native-dependent code for modern i386 BSD's. |
| 2 | Copyright 2000, 2001, 2002 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 19 | Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "inferior.h" |
| 23 | #include "regcache.h" |
| 24 | |
| 25 | #include "gdb_assert.h" |
| 26 | #include <signal.h> |
| 27 | #include <stddef.h> |
| 28 | #include <sys/types.h> |
| 29 | #include <sys/ptrace.h> |
| 30 | #include <machine/reg.h> |
| 31 | #include <machine/frame.h> |
| 32 | |
| 33 | #ifdef HAVE_SYS_PROCFS_H |
| 34 | #include <sys/procfs.h> |
| 35 | #endif |
| 36 | |
| 37 | #ifndef HAVE_GREGSET_T |
| 38 | typedef struct reg gregset_t; |
| 39 | #endif |
| 40 | |
| 41 | #ifndef HAVE_FPREGSET_T |
| 42 | typedef struct fpreg fpregset_t; |
| 43 | #endif |
| 44 | |
| 45 | #include "gregset.h" |
| 46 | #include "i386-tdep.h" |
| 47 | \f |
| 48 | |
| 49 | /* In older BSD versions we cannot get at some of the segment |
| 50 | registers. FreeBSD for example didn't support the %fs and %gs |
| 51 | registers until the 3.0 release. We have autoconf checks for their |
| 52 | presence, and deal gracefully with their absence. */ |
| 53 | |
| 54 | /* Registers we shouldn't try to fetch. */ |
| 55 | #if !defined (CANNOT_FETCH_REGISTER) |
| 56 | #define CANNOT_FETCH_REGISTER(regno) cannot_fetch_register (regno) |
| 57 | #endif |
| 58 | |
| 59 | /* Registers we shouldn't try to store. */ |
| 60 | #if !defined (CANNOT_STORE_REGISTER) |
| 61 | #define CANNOT_STORE_REGISTER(regno) cannot_fetch_register (regno) |
| 62 | #endif |
| 63 | |
| 64 | /* Offset to the gregset_t location where REG is stored. */ |
| 65 | #define REG_OFFSET(reg) offsetof (gregset_t, reg) |
| 66 | |
| 67 | /* At reg_offset[REGNO] you'll find the offset to the gregset_t |
| 68 | location where the GDB register REGNO is stored. Unsupported |
| 69 | registers are marked with `-1'. */ |
| 70 | static int reg_offset[] = |
| 71 | { |
| 72 | REG_OFFSET (r_eax), |
| 73 | REG_OFFSET (r_ecx), |
| 74 | REG_OFFSET (r_edx), |
| 75 | REG_OFFSET (r_ebx), |
| 76 | REG_OFFSET (r_esp), |
| 77 | REG_OFFSET (r_ebp), |
| 78 | REG_OFFSET (r_esi), |
| 79 | REG_OFFSET (r_edi), |
| 80 | REG_OFFSET (r_eip), |
| 81 | REG_OFFSET (r_eflags), |
| 82 | REG_OFFSET (r_cs), |
| 83 | REG_OFFSET (r_ss), |
| 84 | REG_OFFSET (r_ds), |
| 85 | REG_OFFSET (r_es), |
| 86 | #ifdef HAVE_STRUCT_REG_R_FS |
| 87 | REG_OFFSET (r_fs), |
| 88 | #else |
| 89 | -1, |
| 90 | #endif |
| 91 | #ifdef HAVE_STRUCT_REG_R_GS |
| 92 | REG_OFFSET (r_gs) |
| 93 | #else |
| 94 | -1 |
| 95 | #endif |
| 96 | }; |
| 97 | |
| 98 | #define REG_ADDR(regset, regno) ((char *) (regset) + reg_offset[regno]) |
| 99 | |
| 100 | /* Macro to determine if a register is fetched with PT_GETREGS. */ |
| 101 | #define GETREGS_SUPPLIES(regno) \ |
| 102 | ((0 <= (regno) && (regno) <= 15)) |
| 103 | |
| 104 | #ifdef HAVE_PT_GETXMMREGS |
| 105 | /* Set to 1 if the kernel supports PT_GETXMMREGS. Initialized to -1 |
| 106 | so that we try PT_GETXMMREGS the first time around. */ |
| 107 | static int have_ptrace_xmmregs = -1; |
| 108 | #endif |
| 109 | |
| 110 | /* Return nonzero if we shouldn't try to fetch register REGNO. */ |
| 111 | |
| 112 | static int |
| 113 | cannot_fetch_register (int regno) |
| 114 | { |
| 115 | return (reg_offset[regno] == -1); |
| 116 | } |
| 117 | \f |
| 118 | |
| 119 | /* Transfering the registers between GDB, inferiors and core files. */ |
| 120 | |
| 121 | /* Fill GDB's register array with the general-purpose register values |
| 122 | in *GREGSETP. */ |
| 123 | |
| 124 | void |
| 125 | supply_gregset (gregset_t *gregsetp) |
| 126 | { |
| 127 | int i; |
| 128 | |
| 129 | for (i = 0; i < I386_NUM_GREGS; i++) |
| 130 | { |
| 131 | if (CANNOT_FETCH_REGISTER (i)) |
| 132 | supply_register (i, NULL); |
| 133 | else |
| 134 | supply_register (i, REG_ADDR (gregsetp, i)); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | /* Fill register REGNO (if it is a general-purpose register) in |
| 139 | *GREGSETPS with the value in GDB's register array. If REGNO is -1, |
| 140 | do this for all registers. */ |
| 141 | |
| 142 | void |
| 143 | fill_gregset (gregset_t *gregsetp, int regno) |
| 144 | { |
| 145 | int i; |
| 146 | |
| 147 | for (i = 0; i < I386_NUM_GREGS; i++) |
| 148 | if ((regno == -1 || regno == i) && ! CANNOT_STORE_REGISTER (i)) |
| 149 | regcache_collect (i, REG_ADDR (gregsetp, i)); |
| 150 | } |
| 151 | |
| 152 | #include "i387-tdep.h" |
| 153 | |
| 154 | /* Fill GDB's register array with the floating-point register values |
| 155 | in *FPREGSETP. */ |
| 156 | |
| 157 | void |
| 158 | supply_fpregset (fpregset_t *fpregsetp) |
| 159 | { |
| 160 | i387_supply_fsave ((char *) fpregsetp); |
| 161 | } |
| 162 | |
| 163 | /* Fill register REGNO (if it is a floating-point register) in |
| 164 | *FPREGSETP with the value in GDB's register array. If REGNO is -1, |
| 165 | do this for all registers. */ |
| 166 | |
| 167 | void |
| 168 | fill_fpregset (fpregset_t *fpregsetp, int regno) |
| 169 | { |
| 170 | i387_fill_fsave ((char *) fpregsetp, regno); |
| 171 | } |
| 172 | |
| 173 | /* Fetch register REGNO from the inferior. If REGNO is -1, do this |
| 174 | for all registers (including the floating point registers). */ |
| 175 | |
| 176 | void |
| 177 | fetch_inferior_registers (int regno) |
| 178 | { |
| 179 | |
| 180 | if (regno == -1 || GETREGS_SUPPLIES (regno)) |
| 181 | { |
| 182 | gregset_t gregs; |
| 183 | |
| 184 | if (ptrace (PT_GETREGS, PIDGET (inferior_ptid), |
| 185 | (PTRACE_ARG3_TYPE) &gregs, 0) == -1) |
| 186 | perror_with_name ("Couldn't get registers"); |
| 187 | |
| 188 | supply_gregset (&gregs); |
| 189 | if (regno != -1) |
| 190 | return; |
| 191 | } |
| 192 | |
| 193 | if (regno == -1 || regno >= FP0_REGNUM) |
| 194 | { |
| 195 | fpregset_t fpregs; |
| 196 | #ifdef HAVE_PT_GETXMMREGS |
| 197 | char xmmregs[512]; |
| 198 | |
| 199 | if (have_ptrace_xmmregs != 0 && |
| 200 | ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid), |
| 201 | (PTRACE_ARG3_TYPE) xmmregs, 0) == 0) |
| 202 | { |
| 203 | have_ptrace_xmmregs = 1; |
| 204 | i387_supply_fxsave (xmmregs); |
| 205 | } |
| 206 | else |
| 207 | { |
| 208 | if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid), |
| 209 | (PTRACE_ARG3_TYPE) &fpregs, 0) == -1) |
| 210 | perror_with_name ("Couldn't get floating point status"); |
| 211 | |
| 212 | supply_fpregset (&fpregs); |
| 213 | } |
| 214 | #else |
| 215 | if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid), |
| 216 | (PTRACE_ARG3_TYPE) &fpregs, 0) == -1) |
| 217 | perror_with_name ("Couldn't get floating point status"); |
| 218 | |
| 219 | supply_fpregset (&fpregs); |
| 220 | #endif |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | /* Store register REGNO back into the inferior. If REGNO is -1, do |
| 225 | this for all registers (including the floating point registers). */ |
| 226 | |
| 227 | void |
| 228 | store_inferior_registers (int regno) |
| 229 | { |
| 230 | |
| 231 | if (regno == -1 || GETREGS_SUPPLIES (regno)) |
| 232 | { |
| 233 | gregset_t gregs; |
| 234 | |
| 235 | if (ptrace (PT_GETREGS, PIDGET (inferior_ptid), |
| 236 | (PTRACE_ARG3_TYPE) &gregs, 0) == -1) |
| 237 | perror_with_name ("Couldn't get registers"); |
| 238 | |
| 239 | fill_gregset (&gregs, regno); |
| 240 | |
| 241 | if (ptrace (PT_SETREGS, PIDGET (inferior_ptid), |
| 242 | (PTRACE_ARG3_TYPE) &gregs, 0) == -1) |
| 243 | perror_with_name ("Couldn't write registers"); |
| 244 | |
| 245 | if (regno != -1) |
| 246 | return; |
| 247 | } |
| 248 | |
| 249 | if (regno == -1 || regno >= FP0_REGNUM) |
| 250 | { |
| 251 | fpregset_t fpregs; |
| 252 | #ifdef HAVE_PT_GETXMMREGS |
| 253 | char xmmregs[512]; |
| 254 | |
| 255 | if (have_ptrace_xmmregs != 0 && |
| 256 | ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid), |
| 257 | (PTRACE_ARG3_TYPE) xmmregs, 0) == 0) |
| 258 | { |
| 259 | have_ptrace_xmmregs = 1; |
| 260 | |
| 261 | i387_fill_fxsave (xmmregs, regno); |
| 262 | |
| 263 | if (ptrace (PT_SETXMMREGS, PIDGET (inferior_ptid), |
| 264 | (PTRACE_ARG3_TYPE) xmmregs, 0) == -1) |
| 265 | perror_with_name ("Couldn't write XMM registers"); |
| 266 | } |
| 267 | else |
| 268 | { |
| 269 | have_ptrace_xmmregs = 0; |
| 270 | #endif |
| 271 | if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid), |
| 272 | (PTRACE_ARG3_TYPE) &fpregs, 0) == -1) |
| 273 | perror_with_name ("Couldn't get floating point status"); |
| 274 | |
| 275 | fill_fpregset (&fpregs, regno); |
| 276 | |
| 277 | if (ptrace (PT_SETFPREGS, PIDGET (inferior_ptid), |
| 278 | (PTRACE_ARG3_TYPE) &fpregs, 0) == -1) |
| 279 | perror_with_name ("Couldn't write floating point status"); |
| 280 | #ifdef HAVE_PT_GETXMMREGS |
| 281 | } |
| 282 | #endif |
| 283 | } |
| 284 | } |
| 285 | \f |
| 286 | |
| 287 | /* Support for debug registers. */ |
| 288 | |
| 289 | #ifdef HAVE_PT_GETDBREGS |
| 290 | |
| 291 | /* Not all versions of FreeBSD/i386 that support the debug registers |
| 292 | have this macro. */ |
| 293 | #ifndef DBREG_DRX |
| 294 | #define DBREG_DRX(d, x) ((&d->dr0)[x]) |
| 295 | #endif |
| 296 | |
| 297 | static void |
| 298 | i386bsd_dr_set (int regnum, unsigned int value) |
| 299 | { |
| 300 | struct dbreg dbregs; |
| 301 | |
| 302 | if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid), |
| 303 | (PTRACE_ARG3_TYPE) &dbregs, 0) == -1) |
| 304 | perror_with_name ("Couldn't get debug registers"); |
| 305 | |
| 306 | /* For some mysterious reason, some of the reserved bits in the |
| 307 | debug control register get set. Mask these off, otherwise the |
| 308 | ptrace call below will fail. */ |
| 309 | DBREG_DRX ((&dbregs), 7) &= ~(0x0000fc00); |
| 310 | |
| 311 | DBREG_DRX ((&dbregs), regnum) = value; |
| 312 | |
| 313 | if (ptrace (PT_SETDBREGS, PIDGET (inferior_ptid), |
| 314 | (PTRACE_ARG3_TYPE) &dbregs, 0) == -1) |
| 315 | perror_with_name ("Couldn't write debug registers"); |
| 316 | } |
| 317 | |
| 318 | void |
| 319 | i386bsd_dr_set_control (unsigned long control) |
| 320 | { |
| 321 | i386bsd_dr_set (7, control); |
| 322 | } |
| 323 | |
| 324 | void |
| 325 | i386bsd_dr_set_addr (int regnum, CORE_ADDR addr) |
| 326 | { |
| 327 | gdb_assert (regnum >= 0 && regnum <= 4); |
| 328 | |
| 329 | i386bsd_dr_set (regnum, addr); |
| 330 | } |
| 331 | |
| 332 | void |
| 333 | i386bsd_dr_reset_addr (int regnum) |
| 334 | { |
| 335 | gdb_assert (regnum >= 0 && regnum <= 4); |
| 336 | |
| 337 | i386bsd_dr_set (regnum, 0); |
| 338 | } |
| 339 | |
| 340 | unsigned long |
| 341 | i386bsd_dr_get_status (void) |
| 342 | { |
| 343 | struct dbreg dbregs; |
| 344 | |
| 345 | /* FIXME: kettenis/2001-03-31: Calling perror_with_name if the |
| 346 | ptrace call fails breaks debugging remote targets. The correct |
| 347 | way to fix this is to add the hardware breakpoint and watchpoint |
| 348 | stuff to the target vector. For now, just return zero if the |
| 349 | ptrace call fails. */ |
| 350 | if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid), |
| 351 | (PTRACE_ARG3_TYPE) & dbregs, 0) == -1) |
| 352 | #if 0 |
| 353 | perror_with_name ("Couldn't read debug registers"); |
| 354 | #else |
| 355 | return 0; |
| 356 | #endif |
| 357 | |
| 358 | return DBREG_DRX ((&dbregs), 6); |
| 359 | } |
| 360 | |
| 361 | #endif /* PT_GETDBREGS */ |
| 362 | \f |
| 363 | |
| 364 | /* Support for the user struct. */ |
| 365 | |
| 366 | /* Return the address register REGNO. BLOCKEND is the value of |
| 367 | u.u_ar0, which should point to the registers. */ |
| 368 | |
| 369 | CORE_ADDR |
| 370 | register_u_addr (CORE_ADDR blockend, int regno) |
| 371 | { |
| 372 | return (CORE_ADDR) REG_ADDR (blockend, regno); |
| 373 | } |
| 374 | |
| 375 | #include <sys/param.h> |
| 376 | #include <sys/user.h> |
| 377 | |
| 378 | /* Return the size of the user struct. */ |
| 379 | |
| 380 | int |
| 381 | kernel_u_size (void) |
| 382 | { |
| 383 | return (sizeof (struct user)); |
| 384 | } |
| 385 | \f |
| 386 | void |
| 387 | _initialize_i386bsd_nat (void) |
| 388 | { |
| 389 | int offset; |
| 390 | |
| 391 | /* To support the recognition of signal handlers, i386bsd-tdep.c |
| 392 | hardcodes some constants. Inclusion of this file means that we |
| 393 | are compiling a native debugger, which means that we can use the |
| 394 | system header files and sysctl(3) to get at the relevant |
| 395 | information. */ |
| 396 | |
| 397 | #if defined (__FreeBSD_version) && __FreeBSD_version >= 400011 |
| 398 | extern int i386fbsd4_sc_reg_offset[]; |
| 399 | #define SC_REG_OFFSET i386fbsd4_sc_reg_offset |
| 400 | #elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005 |
| 401 | extern int i386fbsd_sc_reg_offset[]; |
| 402 | #define SC_REG_OFFSET i386fbsd_sc_reg_offset |
| 403 | #elif defined (NetBSD) || defined (__NetBSD_Version__) |
| 404 | extern int i386nbsd_sc_reg_offset[]; |
| 405 | #define SC_REG_OFFSET i386nbsd_sc_reg_offset |
| 406 | #elif defined (OpenBSD) |
| 407 | extern int i386obsd_sc_reg_offset[]; |
| 408 | #define SC_REG_OFFSET i386obsd_sc_reg_offset |
| 409 | #else |
| 410 | extern int i386bsd_sc_reg_offset[]; |
| 411 | #define SC_PC_OFFSET i386bsd_sc_reg_offset |
| 412 | #endif |
| 413 | |
| 414 | /* We only check the program counter, stack pointer and frame |
| 415 | pointer since these members of `struct sigcontext' are essential |
| 416 | for providing backtraces. More checks could be added, but would |
| 417 | involve adding configure checks for the appropriate structure |
| 418 | members, since older BSD's don't provide all of them. */ |
| 419 | |
| 420 | #define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM] |
| 421 | #define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM] |
| 422 | #define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM] |
| 423 | |
| 424 | /* Override the default value for the offset of the program counter |
| 425 | in the sigcontext structure. */ |
| 426 | offset = offsetof (struct sigcontext, sc_pc); |
| 427 | |
| 428 | if (SC_PC_OFFSET != offset) |
| 429 | { |
| 430 | warning ("\ |
| 431 | offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\ |
| 432 | Please report this to <bug-gdb@gnu.org>.", |
| 433 | offset, SC_PC_OFFSET); |
| 434 | } |
| 435 | |
| 436 | SC_PC_OFFSET = offset; |
| 437 | |
| 438 | /* Likewise for the stack pointer. */ |
| 439 | offset = offsetof (struct sigcontext, sc_sp); |
| 440 | |
| 441 | if (SC_SP_OFFSET != offset) |
| 442 | { |
| 443 | warning ("\ |
| 444 | offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\ |
| 445 | Please report this to <bug-gdb@gnu.org>.", |
| 446 | offset, SC_SP_OFFSET); |
| 447 | } |
| 448 | |
| 449 | SC_SP_OFFSET = offset; |
| 450 | |
| 451 | /* And the frame pointer. */ |
| 452 | offset = offsetof (struct sigcontext, sc_fp); |
| 453 | |
| 454 | if (SC_FP_OFFSET != offset) |
| 455 | { |
| 456 | warning ("\ |
| 457 | offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\ |
| 458 | Please report this to <bug-gdb@gnu.org>.", |
| 459 | offset, SC_FP_OFFSET); |
| 460 | } |
| 461 | |
| 462 | SC_FP_OFFSET = offset; |
| 463 | } |