1/* Native-dependent code for modern i386 BSD's. 2 3 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007 4 Free Software Foundation, Inc. 5 6 This file is part of GDB. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 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#include "i386-tdep.h" 34#include "i387-tdep.h" 35#include "i386bsd-nat.h" 36#include "inf-ptrace.h" 37 38 39/* In older BSD versions we cannot get at some of the segment 40 registers. FreeBSD for example didn't support the %fs and %gs 41 registers until the 3.0 release. We have autoconf checks for their 42 presence, and deal gracefully with their absence. */ 43 44/* Offset in `struct reg' where MEMBER is stored. */ 45#define REG_OFFSET(member) offsetof (struct reg, member) 46 47/* At i386bsd_reg_offset[REGNUM] you'll find the offset in `struct 48 reg' where the GDB register REGNUM is stored. Unsupported 49 registers are marked with `-1'. */ 50static int i386bsd_r_reg_offset[] = 51{ 52 REG_OFFSET (r_eax), 53 REG_OFFSET (r_ecx), 54 REG_OFFSET (r_edx), 55 REG_OFFSET (r_ebx), 56 REG_OFFSET (r_esp), 57 REG_OFFSET (r_ebp), 58 REG_OFFSET (r_esi), 59 REG_OFFSET (r_edi), 60 REG_OFFSET (r_eip), 61 REG_OFFSET (r_eflags), 62 REG_OFFSET (r_cs), 63 REG_OFFSET (r_ss), 64 REG_OFFSET (r_ds), 65 REG_OFFSET (r_es), 66#ifdef HAVE_STRUCT_REG_R_FS 67 REG_OFFSET (r_fs), 68#else 69 -1, 70#endif 71#ifdef HAVE_STRUCT_REG_R_GS 72 REG_OFFSET (r_gs) 73#else 74 -1 75#endif 76}; 77 78/* Macro to determine if a register is fetched with PT_GETREGS. */ 79#define GETREGS_SUPPLIES(regnum) \ 80 ((0 <= (regnum) && (regnum) <= 15)) 81 82#ifdef HAVE_PT_GETXMMREGS 83/* Set to 1 if the kernel supports PT_GETXMMREGS. Initialized to -1 84 so that we try PT_GETXMMREGS the first time around. */ 85static int have_ptrace_xmmregs = -1; 86#endif 87 88 89/* Supply the general-purpose registers in GREGS, to REGCACHE. */ 90 91static void 92i386bsd_supply_gregset (struct regcache *regcache, const void *gregs) 93{ 94 const char *regs = gregs; 95 int regnum; 96 97 for (regnum = 0; regnum < ARRAY_SIZE (i386bsd_r_reg_offset); regnum++) 98 { 99 int offset = i386bsd_r_reg_offset[regnum]; 100 101 if (offset != -1) 102 regcache_raw_supply (regcache, regnum, regs + offset); 103 } 104} 105 106/* Collect register REGNUM from REGCACHE and store its contents in 107 GREGS. If REGNUM is -1, collect and store all appropriate 108 registers. */ 109 110static void 111i386bsd_collect_gregset (const struct regcache *regcache, 112 void *gregs, int regnum) 113{ 114 char *regs = gregs; 115 int i; 116 117 for (i = 0; i < ARRAY_SIZE (i386bsd_r_reg_offset); i++) 118 { 119 if (regnum == -1 || regnum == i) 120 { 121 int offset = i386bsd_r_reg_offset[i]; 122 123 if (offset != -1) 124 regcache_raw_collect (regcache, i, regs + offset); 125 } 126 } 127} 128 129/* Fetch register REGNUM from the inferior. If REGNUM is -1, do this 130 for all registers (including the floating point registers). */ 131 132static void 133i386bsd_fetch_inferior_registers (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 182static void 183i386bsd_store_inferior_registers (struct regcache *regcache, int regnum) 184{ 185 if (regnum == -1 || GETREGS_SUPPLIES (regnum)) 186 { 187 struct reg regs; 188 189 if (ptrace (PT_GETREGS, PIDGET (inferior_ptid), 190 (PTRACE_TYPE_ARG3) ®s, 0) == -1) 191 perror_with_name (_("Couldn't get registers")); 192 193 i386bsd_collect_gregset (regcache, ®s, regnum); 194 195 if (ptrace (PT_SETREGS, PIDGET (inferior_ptid), 196 (PTRACE_TYPE_ARG3) ®s, 0) == -1) 197 perror_with_name (_("Couldn't write registers")); 198 199 if (regnum != -1) 200 return; 201 } 202 203 if (regnum == -1 || regnum >= I386_ST0_REGNUM) 204 { 205 struct fpreg fpregs; 206#ifdef HAVE_PT_GETXMMREGS 207 char xmmregs[512]; 208 209 if (have_ptrace_xmmregs != 0 210 && ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid), 211 (PTRACE_TYPE_ARG3) xmmregs, 0) == 0) 212 { 213 have_ptrace_xmmregs = 1; 214 215 i387_collect_fxsave (regcache, regnum, xmmregs); 216 217 if (ptrace (PT_SETXMMREGS, PIDGET (inferior_ptid), 218 (PTRACE_TYPE_ARG3) xmmregs, 0) == -1) 219 perror_with_name (_("Couldn't write XMM registers")); 220 } 221 else 222 { 223 have_ptrace_xmmregs = 0; 224#endif 225 if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid), 226 (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 227 perror_with_name (_("Couldn't get floating point status")); 228 229 i387_collect_fsave (regcache, regnum, &fpregs); 230 231 if (ptrace (PT_SETFPREGS, PIDGET (inferior_ptid), 232 (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 233 perror_with_name (_("Couldn't write floating point status")); 234#ifdef HAVE_PT_GETXMMREGS 235 } 236#endif 237 } 238} 239 240/* Create a prototype *BSD/i386 target. The client can override it 241 with local methods. */ 242 243struct target_ops * 244i386bsd_target (void) 245{ 246 struct target_ops *t; 247 248 t = inf_ptrace_target (); 249 t->to_fetch_registers = i386bsd_fetch_inferior_registers; 250 t->to_store_registers = i386bsd_store_inferior_registers; 251 return t; 252} 253 254 255/* Support for debug registers. */ 256 257#ifdef HAVE_PT_GETDBREGS 258 259/* Not all versions of FreeBSD/i386 that support the debug registers 260 have this macro. */ 261#ifndef DBREG_DRX 262#define DBREG_DRX(d, x) ((&d->dr0)[x]) 263#endif 264 265static void 266i386bsd_dr_set (int regnum, unsigned int value) 267{ 268 struct dbreg dbregs; 269 270 if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid), 271 (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) 272 perror_with_name (_("Couldn't get debug registers")); 273 274 /* For some mysterious reason, some of the reserved bits in the 275 debug control register get set. Mask these off, otherwise the 276 ptrace call below will fail. */ 277 DBREG_DRX ((&dbregs), 7) &= ~(0x0000fc00); 278 279 DBREG_DRX ((&dbregs), regnum) = value; 280 281 if (ptrace (PT_SETDBREGS, PIDGET (inferior_ptid), 282 (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) 283 perror_with_name (_("Couldn't write debug registers")); 284} 285 286void 287i386bsd_dr_set_control (unsigned long control) 288{ 289 i386bsd_dr_set (7, control); 290} 291 292void 293i386bsd_dr_set_addr (int regnum, CORE_ADDR addr) 294{ 295 gdb_assert (regnum >= 0 && regnum <= 4); 296 297 i386bsd_dr_set (regnum, addr); 298} 299 300void 301i386bsd_dr_reset_addr (int regnum) 302{ 303 gdb_assert (regnum >= 0 && regnum <= 4); 304 305 i386bsd_dr_set (regnum, 0); 306} 307 308unsigned long 309i386bsd_dr_get_status (void) 310{ 311 struct dbreg dbregs; 312 313 /* FIXME: kettenis/2001-03-31: Calling perror_with_name if the 314 ptrace call fails breaks debugging remote targets. The correct 315 way to fix this is to add the hardware breakpoint and watchpoint 316 stuff to the target vector. For now, just return zero if the 317 ptrace call fails. */ 318 if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid), 319 (PTRACE_TYPE_ARG3) &dbregs, 0) == -1) 320#if 0 321 perror_with_name (_("Couldn't read debug registers")); 322#else 323 return 0; 324#endif 325 326 return DBREG_DRX ((&dbregs), 6); 327} 328 329#endif /* PT_GETDBREGS */ 330 331 332void 333_initialize_i386bsd_nat (void) 334{ 335 int offset; 336 337 /* To support the recognition of signal handlers, i386bsd-tdep.c 338 hardcodes some constants. Inclusion of this file means that we 339 are compiling a native debugger, which means that we can use the 340 system header files and sysctl(3) to get at the relevant 341 information. */ 342 343#if defined (__FreeBSD_version) && __FreeBSD_version >= 400011 344#define SC_REG_OFFSET i386fbsd4_sc_reg_offset 345#elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005 346#define SC_REG_OFFSET i386fbsd_sc_reg_offset 347#elif defined (NetBSD) || defined (__NetBSD_Version__) 348#define SC_REG_OFFSET i386nbsd_sc_reg_offset 349#elif defined (OpenBSD) 350#define SC_REG_OFFSET i386obsd_sc_reg_offset 351#endif 352 353#ifdef SC_REG_OFFSET 354 355 /* We only check the program counter, stack pointer and frame 356 pointer since these members of `struct sigcontext' are essential 357 for providing backtraces. More checks could be added, but would 358 involve adding configure checks for the appropriate structure 359 members, since older BSD's don't provide all of them. */ 360 361#define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM] 362#define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM] 363#define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM] 364 365 /* Override the default value for the offset of the program counter 366 in the sigcontext structure. */ 367 offset = offsetof (struct sigcontext, sc_pc); 368 369 if (SC_PC_OFFSET != offset) 370 { 371 warning (_("\ 372offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\ 373Please report this to <bug-gdb@gnu.org>."), 374 offset, SC_PC_OFFSET); 375 } 376 377 SC_PC_OFFSET = offset; 378 379 /* Likewise for the stack pointer. */ 380 offset = offsetof (struct sigcontext, sc_sp); 381 382 if (SC_SP_OFFSET != offset) 383 { 384 warning (_("\ 385offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\ 386Please report this to <bug-gdb@gnu.org>."), 387 offset, SC_SP_OFFSET); 388 } 389 390 SC_SP_OFFSET = offset; 391 392 /* And the frame pointer. */ 393 offset = offsetof (struct sigcontext, sc_fp); 394 395 if (SC_FP_OFFSET != offset) 396 { 397 warning (_("\ 398offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\ 399Please report this to <bug-gdb@gnu.org>."), 400 offset, SC_FP_OFFSET); 401 } 402 403 SC_FP_OFFSET = offset; 404 405#endif /* SC_REG_OFFSET */ 406} 407