1 /* Native-dependent code for modern i386 BSD's. 2 3 Copyright (C) 2000-2013 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 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 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, PIDGET (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, PIDGET (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, PIDGET (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, PIDGET (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, PIDGET (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, 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 (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 (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 unsigned long 267 i386bsd_dr_get (ptid_t ptid, int regnum) 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 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, PIDGET (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, PIDGET (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 */ 332 333 334 /* 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 #elif defined (DragonFly) 357 #define SC_REG_OFFSET i386dfly_sc_reg_offset 358 #endif 359 360 #ifdef SC_REG_OFFSET 361 362 /* We only check the program counter, stack pointer and frame 363 pointer since these members of `struct sigcontext' are essential 364 for providing backtraces. More checks could be added, but would 365 involve adding configure checks for the appropriate structure 366 members, since older BSD's don't provide all of them. */ 367 368 #define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM] 369 #define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM] 370 #define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM] 371 372 /* Override the default value for the offset of the program counter 373 in the sigcontext structure. */ 374 offset = offsetof (struct sigcontext, sc_pc); 375 376 if (SC_PC_OFFSET != offset) 377 { 378 warning (_("\ 379 offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\ 380 Please report this to <bug-gdb@gnu.org>."), 381 offset, SC_PC_OFFSET); 382 } 383 384 SC_PC_OFFSET = offset; 385 386 /* Likewise for the stack pointer. */ 387 offset = offsetof (struct sigcontext, sc_sp); 388 389 if (SC_SP_OFFSET != offset) 390 { 391 warning (_("\ 392 offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\ 393 Please report this to <bug-gdb@gnu.org>."), 394 offset, SC_SP_OFFSET); 395 } 396 397 SC_SP_OFFSET = offset; 398 399 /* And the frame pointer. */ 400 offset = offsetof (struct sigcontext, sc_fp); 401 402 if (SC_FP_OFFSET != offset) 403 { 404 warning (_("\ 405 offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\ 406 Please report this to <bug-gdb@gnu.org>."), 407 offset, SC_FP_OFFSET); 408 } 409 410 SC_FP_OFFSET = offset; 411 412 #endif /* SC_REG_OFFSET */ 413 } 414