1 /* Native-dependent code for modern i386 BSD's. 2 3 Copyright 2000, 2001, 2002, 2003, 2004 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 2 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, write to the Free Software 19 Foundation, Inc., 59 Temple Place - Suite 330, 20 Boston, MA 02111-1307, USA. */ 21 22 #include "defs.h" 23 #include "inferior.h" 24 #include "regcache.h" 25 26 #include "gdb_assert.h" 27 #include <signal.h> 28 #include <stddef.h> 29 #include <sys/types.h> 30 #include <sys/ptrace.h> 31 #include <machine/reg.h> 32 #include <machine/frame.h> 33 34 #include "i386-tdep.h" 35 #include "i387-tdep.h" 36 #include "i386bsd-nat.h" 37 #include "inf-ptrace.h" 38 39 40 /* In older BSD versions we cannot get at some of the segment 41 registers. FreeBSD for example didn't support the %fs and %gs 42 registers until the 3.0 release. We have autoconf checks for their 43 presence, and deal gracefully with their absence. */ 44 45 /* Offset in `struct reg' where MEMBER is stored. */ 46 #define REG_OFFSET(member) offsetof (struct reg, member) 47 48 /* At i386bsd_reg_offset[REGNUM] you'll find the offset in `struct 49 reg' where the GDB register REGNUM is stored. Unsupported 50 registers are marked with `-1'. */ 51 static int i386bsd_r_reg_offset[] = 52 { 53 REG_OFFSET (r_eax), 54 REG_OFFSET (r_ecx), 55 REG_OFFSET (r_edx), 56 REG_OFFSET (r_ebx), 57 REG_OFFSET (r_esp), 58 REG_OFFSET (r_ebp), 59 REG_OFFSET (r_esi), 60 REG_OFFSET (r_edi), 61 REG_OFFSET (r_eip), 62 REG_OFFSET (r_eflags), 63 REG_OFFSET (r_cs), 64 REG_OFFSET (r_ss), 65 REG_OFFSET (r_ds), 66 REG_OFFSET (r_es), 67 #ifdef HAVE_STRUCT_REG_R_FS 68 REG_OFFSET (r_fs), 69 #else 70 -1, 71 #endif 72 #ifdef HAVE_STRUCT_REG_R_GS 73 REG_OFFSET (r_gs) 74 #else 75 -1 76 #endif 77 }; 78 79 /* Macro to determine if a register is fetched with PT_GETREGS. */ 80 #define GETREGS_SUPPLIES(regnum) \ 81 ((0 <= (regnum) && (regnum) <= 15)) 82 83 #ifdef HAVE_PT_GETXMMREGS 84 /* Set to 1 if the kernel supports PT_GETXMMREGS. Initialized to -1 85 so that we try PT_GETXMMREGS the first time around. */ 86 static int have_ptrace_xmmregs = -1; 87 #endif 88 89 90 /* Supply the general-purpose registers in GREGS, to REGCACHE. */ 91 92 static void 93 i386bsd_supply_gregset (struct regcache *regcache, const void *gregs) 94 { 95 const char *regs = gregs; 96 int regnum; 97 98 for (regnum = 0; regnum < ARRAY_SIZE (i386bsd_r_reg_offset); regnum++) 99 { 100 int offset = i386bsd_r_reg_offset[regnum]; 101 102 if (offset != -1) 103 regcache_raw_supply (regcache, regnum, regs + offset); 104 } 105 } 106 107 /* Collect register REGNUM from REGCACHE and store its contents in 108 GREGS. If REGNUM is -1, collect and store all appropriate 109 registers. */ 110 111 static void 112 i386bsd_collect_gregset (const struct regcache *regcache, 113 void *gregs, int regnum) 114 { 115 char *regs = gregs; 116 int i; 117 118 for (i = 0; i < ARRAY_SIZE (i386bsd_r_reg_offset); i++) 119 { 120 if (regnum == -1 || regnum == i) 121 { 122 int offset = i386bsd_r_reg_offset[i]; 123 124 if (offset != -1) 125 regcache_raw_collect (regcache, i, regs + offset); 126 } 127 } 128 } 129 130 /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this 131 for all registers (including the floating point registers). */ 132 133 static void 134 i386bsd_fetch_inferior_registers (int regnum) 135 { 136 if (regnum == -1 || GETREGS_SUPPLIES (regnum)) 137 { 138 struct reg regs; 139 140 if (ptrace (PT_GETREGS, PIDGET (inferior_ptid), 141 (PTRACE_TYPE_ARG3) ®s, 0) == -1) 142 perror_with_name ("Couldn't get registers"); 143 144 i386bsd_supply_gregset (current_regcache, ®s); 145 if (regnum != -1) 146 return; 147 } 148 149 if (regnum == -1 || regnum >= I386_ST0_REGNUM) 150 { 151 struct fpreg fpregs; 152 #ifdef HAVE_PT_GETXMMREGS 153 char xmmregs[512]; 154 155 if (have_ptrace_xmmregs != 0 156 && ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid), 157 (PTRACE_TYPE_ARG3) xmmregs, 0) == 0) 158 { 159 have_ptrace_xmmregs = 1; 160 i387_supply_fxsave (current_regcache, -1, xmmregs); 161 } 162 else 163 { 164 if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid), 165 (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 166 perror_with_name ("Couldn't get floating point status"); 167 168 i387_supply_fsave (current_regcache, -1, &fpregs); 169 } 170 #else 171 if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid), 172 (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 173 perror_with_name ("Couldn't get floating point status"); 174 175 i387_supply_fsave (current_regcache, -1, &fpregs); 176 #endif 177 } 178 } 179 180 /* Store register REGNUM back into the inferior. If REGNUM is -1, do 181 this for all registers (including the floating point registers). */ 182 183 static void 184 i386bsd_store_inferior_registers (int regnum) 185 { 186 if (regnum == -1 || GETREGS_SUPPLIES (regnum)) 187 { 188 struct reg regs; 189 190 if (ptrace (PT_GETREGS, PIDGET (inferior_ptid), 191 (PTRACE_TYPE_ARG3) ®s, 0) == -1) 192 perror_with_name ("Couldn't get registers"); 193 194 i386bsd_collect_gregset (current_regcache, ®s, regnum); 195 196 if (ptrace (PT_SETREGS, PIDGET (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, PIDGET (inferior_ptid), 212 (PTRACE_TYPE_ARG3) xmmregs, 0) == 0) 213 { 214 have_ptrace_xmmregs = 1; 215 216 i387_collect_fxsave (current_regcache, regnum, xmmregs); 217 218 if (ptrace (PT_SETXMMREGS, PIDGET (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, PIDGET (inferior_ptid), 227 (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 228 perror_with_name ("Couldn't get floating point status"); 229 230 i387_collect_fsave (current_regcache, regnum, &fpregs); 231 232 if (ptrace (PT_SETFPREGS, PIDGET (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 } 254 255 256 /* 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 void 267 i386bsd_dr_set (int regnum, unsigned int value) 268 { 269 struct dbreg dbregs; 270 271 if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid), 272 (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) 273 perror_with_name ("Couldn't get debug registers"); 274 275 /* For some mysterious reason, some of the reserved bits in the 276 debug control register get set. Mask these off, otherwise the 277 ptrace call below will fail. */ 278 DBREG_DRX ((&dbregs), 7) &= ~(0x0000fc00); 279 280 DBREG_DRX ((&dbregs), regnum) = value; 281 282 if (ptrace (PT_SETDBREGS, PIDGET (inferior_ptid), 283 (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) 284 perror_with_name ("Couldn't write debug registers"); 285 } 286 287 void 288 i386bsd_dr_set_control (unsigned long control) 289 { 290 i386bsd_dr_set (7, control); 291 } 292 293 void 294 i386bsd_dr_set_addr (int regnum, CORE_ADDR addr) 295 { 296 gdb_assert (regnum >= 0 && regnum <= 4); 297 298 i386bsd_dr_set (regnum, addr); 299 } 300 301 void 302 i386bsd_dr_reset_addr (int regnum) 303 { 304 gdb_assert (regnum >= 0 && regnum <= 4); 305 306 i386bsd_dr_set (regnum, 0); 307 } 308 309 unsigned long 310 i386bsd_dr_get_status (void) 311 { 312 struct dbreg dbregs; 313 314 /* FIXME: kettenis/2001-03-31: Calling perror_with_name if the 315 ptrace call fails breaks debugging remote targets. The correct 316 way to fix this is to add the hardware breakpoint and watchpoint 317 stuff to the target vector. For now, just return zero if the 318 ptrace call fails. */ 319 if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid), 320 (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) 321 #if 0 322 perror_with_name ("Couldn't read debug registers"); 323 #else 324 return 0; 325 #endif 326 327 return DBREG_DRX ((&dbregs), 6); 328 } 329 330 #endif /* PT_GETDBREGS */ 331 332 333 /* Support for the user struct. */ 334 335 /* Return the address register REGNUM. BLOCKEND is the value of 336 u.u_ar0, which should point to the registers. */ 337 338 CORE_ADDR 339 register_u_addr (CORE_ADDR blockend, int regnum) 340 { 341 gdb_assert (regnum >= 0 && regnum < ARRAY_SIZE (i386bsd_r_reg_offset)); 342 343 return blockend + i386bsd_r_reg_offset[regnum]; 344 } 345 346 #include <sys/param.h> 347 #include <sys/user.h> 348 349 /* Return the size of the user struct. */ 350 351 int 352 kernel_u_size (void) 353 { 354 return (sizeof (struct user)); 355 } 356 357 void 358 _initialize_i386bsd_nat (void) 359 { 360 int offset; 361 362 /* To support the recognition of signal handlers, i386bsd-tdep.c 363 hardcodes some constants. Inclusion of this file means that we 364 are compiling a native debugger, which means that we can use the 365 system header files and sysctl(3) to get at the relevant 366 information. */ 367 368 #if defined (__FreeBSD_version) && __FreeBSD_version >= 400011 369 #define SC_REG_OFFSET i386fbsd4_sc_reg_offset 370 #elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005 371 #define SC_REG_OFFSET i386fbsd_sc_reg_offset 372 #elif defined (NetBSD) || defined (__NetBSD_Version__) 373 #define SC_REG_OFFSET i386nbsd_sc_reg_offset 374 #elif defined (OpenBSD) 375 #define SC_REG_OFFSET i386obsd_sc_reg_offset 376 #endif 377 378 #ifdef SC_REG_OFFSET 379 380 /* We only check the program counter, stack pointer and frame 381 pointer since these members of `struct sigcontext' are essential 382 for providing backtraces. More checks could be added, but would 383 involve adding configure checks for the appropriate structure 384 members, since older BSD's don't provide all of them. */ 385 386 #define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM] 387 #define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM] 388 #define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM] 389 390 /* Override the default value for the offset of the program counter 391 in the sigcontext structure. */ 392 offset = offsetof (struct sigcontext, sc_pc); 393 394 if (SC_PC_OFFSET != offset) 395 { 396 warning ("\ 397 offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\ 398 Please report this to <bug-gdb@gnu.org>.", 399 offset, SC_PC_OFFSET); 400 } 401 402 SC_PC_OFFSET = offset; 403 404 /* Likewise for the stack pointer. */ 405 offset = offsetof (struct sigcontext, sc_sp); 406 407 if (SC_SP_OFFSET != offset) 408 { 409 warning ("\ 410 offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\ 411 Please report this to <bug-gdb@gnu.org>.", 412 offset, SC_SP_OFFSET); 413 } 414 415 SC_SP_OFFSET = offset; 416 417 /* And the frame pointer. */ 418 offset = offsetof (struct sigcontext, sc_fp); 419 420 if (SC_FP_OFFSET != offset) 421 { 422 warning ("\ 423 offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\ 424 Please report this to <bug-gdb@gnu.org>.", 425 offset, SC_FP_OFFSET); 426 } 427 428 SC_FP_OFFSET = offset; 429 430 #endif /* SC_REG_OFFSET */ 431 } 432