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 int pid; 137 138 /* Cater for systems like OpenBSD, that implement threads as 139 separate processes. */ 140 pid = ptid_get_lwp (inferior_ptid); 141 if (pid == 0) 142 pid = ptid_get_pid (inferior_ptid); 143 144 if (regnum == -1 || GETREGS_SUPPLIES (regnum)) 145 { 146 struct reg regs; 147 148 if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) ®s, 0) == -1) 149 perror_with_name ("Couldn't get registers"); 150 151 i386bsd_supply_gregset (current_regcache, ®s); 152 if (regnum != -1) 153 return; 154 } 155 156 if (regnum == -1 || regnum >= I386_ST0_REGNUM) 157 { 158 struct fpreg fpregs; 159 #ifdef HAVE_PT_GETXMMREGS 160 char xmmregs[512]; 161 162 if (have_ptrace_xmmregs != 0 163 && ptrace(PT_GETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == 0) 164 { 165 have_ptrace_xmmregs = 1; 166 i387_supply_fxsave (current_regcache, -1, xmmregs); 167 } 168 else 169 { 170 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 171 perror_with_name ("Couldn't get floating point status"); 172 173 i387_supply_fsave (current_regcache, -1, &fpregs); 174 } 175 #else 176 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 177 perror_with_name ("Couldn't get floating point status"); 178 179 i387_supply_fsave (current_regcache, -1, &fpregs); 180 #endif 181 } 182 } 183 184 /* Store register REGNUM back into the inferior. If REGNUM is -1, do 185 this for all registers (including the floating point registers). */ 186 187 static void 188 i386bsd_store_inferior_registers (int regnum) 189 { 190 int pid; 191 192 /* Cater for systems like OpenBSD, that implement threads as 193 separate processes. */ 194 pid = ptid_get_lwp (inferior_ptid); 195 if (pid == 0) 196 pid = ptid_get_pid (inferior_ptid); 197 198 if (regnum == -1 || GETREGS_SUPPLIES (regnum)) 199 { 200 struct reg regs; 201 202 if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) ®s, 0) == -1) 203 perror_with_name ("Couldn't get registers"); 204 205 i386bsd_collect_gregset (current_regcache, ®s, regnum); 206 207 if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) ®s, 0) == -1) 208 perror_with_name ("Couldn't write registers"); 209 210 if (regnum != -1) 211 return; 212 } 213 214 if (regnum == -1 || regnum >= I386_ST0_REGNUM) 215 { 216 struct fpreg fpregs; 217 #ifdef HAVE_PT_GETXMMREGS 218 char xmmregs[512]; 219 220 if (have_ptrace_xmmregs != 0 221 && ptrace(PT_GETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == 0) 222 { 223 have_ptrace_xmmregs = 1; 224 225 i387_collect_fxsave (current_regcache, regnum, xmmregs); 226 227 if (ptrace (PT_SETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == -1) 228 perror_with_name ("Couldn't write XMM registers"); 229 } 230 else 231 { 232 have_ptrace_xmmregs = 0; 233 #endif 234 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 235 perror_with_name ("Couldn't get floating point status"); 236 237 i387_collect_fsave (current_regcache, regnum, &fpregs); 238 239 if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 240 perror_with_name ("Couldn't write floating point status"); 241 #ifdef HAVE_PT_GETXMMREGS 242 } 243 #endif 244 } 245 } 246 247 /* Create a prototype *BSD/i386 target. The client can override it 248 with local methods. */ 249 250 struct target_ops * 251 i386bsd_target (void) 252 { 253 struct target_ops *t; 254 255 t = inf_ptrace_target (); 256 t->to_fetch_registers = i386bsd_fetch_inferior_registers; 257 t->to_store_registers = i386bsd_store_inferior_registers; 258 return t; 259 } 260 261 262 /* Support for debug registers. */ 263 264 #ifdef HAVE_PT_GETDBREGS 265 266 /* Not all versions of FreeBSD/i386 that support the debug registers 267 have this macro. */ 268 #ifndef DBREG_DRX 269 #define DBREG_DRX(d, x) ((&d->dr0)[x]) 270 #endif 271 272 static void 273 i386bsd_dr_set (int regnum, unsigned int value) 274 { 275 struct dbreg dbregs; 276 277 if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid), 278 (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) 279 perror_with_name ("Couldn't get debug registers"); 280 281 /* For some mysterious reason, some of the reserved bits in the 282 debug control register get set. Mask these off, otherwise the 283 ptrace call below will fail. */ 284 DBREG_DRX ((&dbregs), 7) &= ~(0x0000fc00); 285 286 DBREG_DRX ((&dbregs), regnum) = value; 287 288 if (ptrace (PT_SETDBREGS, PIDGET (inferior_ptid), 289 (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) 290 perror_with_name ("Couldn't write debug registers"); 291 } 292 293 void 294 i386bsd_dr_set_control (unsigned long control) 295 { 296 i386bsd_dr_set (7, control); 297 } 298 299 void 300 i386bsd_dr_set_addr (int regnum, CORE_ADDR addr) 301 { 302 gdb_assert (regnum >= 0 && regnum <= 4); 303 304 i386bsd_dr_set (regnum, addr); 305 } 306 307 void 308 i386bsd_dr_reset_addr (int regnum) 309 { 310 gdb_assert (regnum >= 0 && regnum <= 4); 311 312 i386bsd_dr_set (regnum, 0); 313 } 314 315 unsigned long 316 i386bsd_dr_get_status (void) 317 { 318 struct dbreg dbregs; 319 320 /* FIXME: kettenis/2001-03-31: Calling perror_with_name if the 321 ptrace call fails breaks debugging remote targets. The correct 322 way to fix this is to add the hardware breakpoint and watchpoint 323 stuff to the target vector. For now, just return zero if the 324 ptrace call fails. */ 325 if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid), 326 (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) 327 #if 0 328 perror_with_name ("Couldn't read debug registers"); 329 #else 330 return 0; 331 #endif 332 333 return DBREG_DRX ((&dbregs), 6); 334 } 335 336 #endif /* PT_GETDBREGS */ 337 338 339 /* Support for the user struct. */ 340 341 /* Return the address register REGNUM. BLOCKEND is the value of 342 u.u_ar0, which should point to the registers. */ 343 344 CORE_ADDR 345 register_u_addr (CORE_ADDR blockend, int regnum) 346 { 347 gdb_assert (regnum >= 0 && regnum < ARRAY_SIZE (i386bsd_r_reg_offset)); 348 349 return blockend + i386bsd_r_reg_offset[regnum]; 350 } 351 352 #include <sys/param.h> 353 #include <sys/user.h> 354 355 /* Return the size of the user struct. */ 356 357 int 358 kernel_u_size (void) 359 { 360 return (sizeof (struct user)); 361 } 362 363 void 364 _initialize_i386bsd_nat (void) 365 { 366 int offset; 367 368 /* To support the recognition of signal handlers, i386bsd-tdep.c 369 hardcodes some constants. Inclusion of this file means that we 370 are compiling a native debugger, which means that we can use the 371 system header files and sysctl(3) to get at the relevant 372 information. */ 373 374 #if defined (__FreeBSD_version) && __FreeBSD_version >= 400011 375 #define SC_REG_OFFSET i386fbsd4_sc_reg_offset 376 #elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005 377 #define SC_REG_OFFSET i386fbsd_sc_reg_offset 378 #elif defined (NetBSD) || defined (__NetBSD_Version__) 379 #define SC_REG_OFFSET i386nbsd_sc_reg_offset 380 #elif defined (OpenBSD) 381 #define SC_REG_OFFSET i386obsd_sc_reg_offset 382 #endif 383 384 #ifdef SC_REG_OFFSET 385 386 /* We only check the program counter, stack pointer and frame 387 pointer since these members of `struct sigcontext' are essential 388 for providing backtraces. More checks could be added, but would 389 involve adding configure checks for the appropriate structure 390 members, since older BSD's don't provide all of them. */ 391 392 #define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM] 393 #define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM] 394 #define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM] 395 396 /* Override the default value for the offset of the program counter 397 in the sigcontext structure. */ 398 offset = offsetof (struct sigcontext, sc_pc); 399 400 if (SC_PC_OFFSET != offset) 401 { 402 warning ("\ 403 offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\ 404 Please report this to <bug-gdb@gnu.org>.", 405 offset, SC_PC_OFFSET); 406 } 407 408 SC_PC_OFFSET = offset; 409 410 /* Likewise for the stack pointer. */ 411 offset = offsetof (struct sigcontext, sc_sp); 412 413 if (SC_SP_OFFSET != offset) 414 { 415 warning ("\ 416 offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\ 417 Please report this to <bug-gdb@gnu.org>.", 418 offset, SC_SP_OFFSET); 419 } 420 421 SC_SP_OFFSET = offset; 422 423 /* And the frame pointer. */ 424 offset = offsetof (struct sigcontext, sc_fp); 425 426 if (SC_FP_OFFSET != offset) 427 { 428 warning ("\ 429 offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\ 430 Please report this to <bug-gdb@gnu.org>.", 431 offset, SC_FP_OFFSET); 432 } 433 434 SC_FP_OFFSET = offset; 435 436 #endif /* SC_REG_OFFSET */ 437 } 438