1 /* Native-dependent code for modern i386 BSD's. 2 3 Copyright (C) 2000-2019 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 <signal.h> 25 #include <sys/types.h> 26 #include <sys/ptrace.h> 27 #include <machine/reg.h> 28 #include <machine/frame.h> 29 30 #include "i386-tdep.h" 31 #include "i387-tdep.h" 32 #include "x86-bsd-nat.h" 33 #include "i386-bsd-nat.h" 34 #include "inf-ptrace.h" 35 36 37 /* In older BSD versions we cannot get at some of the segment 38 registers. FreeBSD for example didn't support the %fs and %gs 39 registers until the 3.0 release. We have autoconf checks for their 40 presence, and deal gracefully with their absence. */ 41 42 /* Offset in `struct reg' where MEMBER is stored. */ 43 #define REG_OFFSET(member) offsetof (struct reg, member) 44 45 /* At i386bsd_reg_offset[REGNUM] you'll find the offset in `struct 46 reg' where the GDB register REGNUM is stored. Unsupported 47 registers are marked with `-1'. */ 48 static int i386bsd_r_reg_offset[] = 49 { 50 REG_OFFSET (r_eax), 51 REG_OFFSET (r_ecx), 52 REG_OFFSET (r_edx), 53 REG_OFFSET (r_ebx), 54 REG_OFFSET (r_esp), 55 REG_OFFSET (r_ebp), 56 REG_OFFSET (r_esi), 57 REG_OFFSET (r_edi), 58 REG_OFFSET (r_eip), 59 REG_OFFSET (r_eflags), 60 REG_OFFSET (r_cs), 61 REG_OFFSET (r_ss), 62 REG_OFFSET (r_ds), 63 REG_OFFSET (r_es), 64 #ifdef HAVE_STRUCT_REG_R_FS 65 REG_OFFSET (r_fs), 66 #else 67 -1, 68 #endif 69 #ifdef HAVE_STRUCT_REG_R_GS 70 REG_OFFSET (r_gs) 71 #else 72 -1 73 #endif 74 }; 75 76 /* Macro to determine if a register is fetched with PT_GETREGS. */ 77 #define GETREGS_SUPPLIES(regnum) \ 78 ((0 <= (regnum) && (regnum) <= 15)) 79 80 #ifdef HAVE_PT_GETXMMREGS 81 /* Set to 1 if the kernel supports PT_GETXMMREGS. Initialized to -1 82 so that we try PT_GETXMMREGS the first time around. */ 83 static int have_ptrace_xmmregs = -1; 84 #endif 85 86 87 /* Supply the general-purpose registers in GREGS, to REGCACHE. */ 88 89 static void 90 i386bsd_supply_gregset (struct regcache *regcache, const void *gregs) 91 { 92 const char *regs = (const char *) gregs; 93 int regnum; 94 95 for (regnum = 0; regnum < ARRAY_SIZE (i386bsd_r_reg_offset); regnum++) 96 { 97 int offset = i386bsd_r_reg_offset[regnum]; 98 99 if (offset != -1) 100 regcache->raw_supply (regnum, regs + offset); 101 } 102 } 103 104 /* Collect register REGNUM from REGCACHE and store its contents in 105 GREGS. If REGNUM is -1, collect and store all appropriate 106 registers. */ 107 108 static void 109 i386bsd_collect_gregset (const struct regcache *regcache, 110 void *gregs, int regnum) 111 { 112 char *regs = (char *) gregs; 113 int i; 114 115 for (i = 0; i < ARRAY_SIZE (i386bsd_r_reg_offset); i++) 116 { 117 if (regnum == -1 || regnum == i) 118 { 119 int offset = i386bsd_r_reg_offset[i]; 120 121 if (offset != -1) 122 regcache->raw_collect (i, regs + offset); 123 } 124 } 125 } 126 127 /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this 128 for all registers (including the floating point registers). */ 129 130 void 131 i386bsd_fetch_inferior_registers (struct regcache *regcache, int regnum) 132 { 133 pid_t pid = get_ptrace_pid (regcache->ptid ()); 134 int lwp = regcache->ptid ().lwp (); 135 136 if (regnum == -1 || GETREGS_SUPPLIES (regnum)) 137 { 138 struct reg regs; 139 140 if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) ®s, lwp) == -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 #endif 154 155 #ifdef PT_GETXSTATE_INFO 156 if (x86bsd_xsave_len != 0) 157 { 158 void *xstateregs; 159 160 xstateregs = alloca (x86bsd_xsave_len); 161 if (ptrace (PT_GETXSTATE, pid, 162 (PTRACE_TYPE_ARG3) xstateregs, lwp) == -1) 163 perror_with_name (_("Couldn't get extended state status")); 164 165 i387_supply_xsave (regcache, -1, xstateregs); 166 return; 167 } 168 #endif 169 170 #ifdef HAVE_PT_GETXMMREGS 171 if (have_ptrace_xmmregs != 0 172 && ptrace(PT_GETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, lwp) == 0) 173 { 174 have_ptrace_xmmregs = 1; 175 i387_supply_fxsave (regcache, -1, xmmregs); 176 } 177 else 178 { 179 have_ptrace_xmmregs = 0; 180 #endif 181 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, lwp) == -1) 182 perror_with_name (_("Couldn't get floating point status")); 183 184 i387_supply_fsave (regcache, -1, &fpregs); 185 #ifdef HAVE_PT_GETXMMREGS 186 } 187 #endif 188 } 189 } 190 191 /* Store register REGNUM back into the inferior. If REGNUM is -1, do 192 this for all registers (including the floating point registers). */ 193 194 void 195 i386bsd_store_inferior_registers (struct regcache *regcache, int regnum) 196 { 197 pid_t pid = get_ptrace_pid (regcache->ptid ()); 198 int lwp = regcache->ptid ().lwp (); 199 200 if (regnum == -1 || GETREGS_SUPPLIES (regnum)) 201 { 202 struct reg regs; 203 204 if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) ®s, lwp) == -1) 205 perror_with_name (_("Couldn't get registers")); 206 207 i386bsd_collect_gregset (regcache, ®s, regnum); 208 209 if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) ®s, lwp) == -1) 210 perror_with_name (_("Couldn't write registers")); 211 212 if (regnum != -1) 213 return; 214 } 215 216 if (regnum == -1 || regnum >= I386_ST0_REGNUM) 217 { 218 struct fpreg fpregs; 219 #ifdef HAVE_PT_GETXMMREGS 220 char xmmregs[512]; 221 #endif 222 223 #ifdef PT_GETXSTATE_INFO 224 if (x86bsd_xsave_len != 0) 225 { 226 void *xstateregs; 227 228 xstateregs = alloca (x86bsd_xsave_len); 229 if (ptrace (PT_GETXSTATE, pid, 230 (PTRACE_TYPE_ARG3) xstateregs, lwp) == -1) 231 perror_with_name (_("Couldn't get extended state status")); 232 233 i387_collect_xsave (regcache, -1, xstateregs, lwp); 234 235 if (ptrace (PT_SETXSTATE, pid, 236 (PTRACE_TYPE_ARG3) xstateregs, x86bsd_xsave_len) == -1) 237 perror_with_name (_("Couldn't write extended state status")); 238 return; 239 } 240 #endif 241 242 #ifdef HAVE_PT_GETXMMREGS 243 if (have_ptrace_xmmregs != 0 244 && ptrace(PT_GETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, lwp) == 0) 245 { 246 have_ptrace_xmmregs = 1; 247 248 i387_collect_fxsave (regcache, regnum, xmmregs); 249 250 if (ptrace (PT_SETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, lwp) == -1) 251 perror_with_name (_("Couldn't write XMM registers")); 252 } 253 else 254 { 255 have_ptrace_xmmregs = 0; 256 #endif 257 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, lwp) == -1) 258 perror_with_name (_("Couldn't get floating point status")); 259 260 i387_collect_fsave (regcache, regnum, &fpregs); 261 262 if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, lwp) == -1) 263 perror_with_name (_("Couldn't write floating point status")); 264 #ifdef HAVE_PT_GETXMMREGS 265 } 266 #endif 267 } 268 } 269 270 void 271 _initialize_i386bsd_nat (void) 272 { 273 int offset; 274 275 /* To support the recognition of signal handlers, i386-bsd-tdep.c 276 hardcodes some constants. Inclusion of this file means that we 277 are compiling a native debugger, which means that we can use the 278 system header files and sysctl(3) to get at the relevant 279 information. */ 280 281 #if defined (__FreeBSD_version) && __FreeBSD_version >= 400011 282 #define SC_REG_OFFSET i386fbsd4_sc_reg_offset 283 #elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005 284 #define SC_REG_OFFSET i386fbsd_sc_reg_offset 285 #elif defined (NetBSD) || defined (__NetBSD_Version__) 286 #define SC_REG_OFFSET i386nbsd_sc_reg_offset 287 #elif defined (OpenBSD) 288 #define SC_REG_OFFSET i386obsd_sc_reg_offset 289 #endif 290 291 #ifdef SC_REG_OFFSET 292 293 /* We only check the program counter, stack pointer and frame 294 pointer since these members of `struct sigcontext' are essential 295 for providing backtraces. More checks could be added, but would 296 involve adding configure checks for the appropriate structure 297 members, since older BSD's don't provide all of them. */ 298 299 #define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM] 300 #define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM] 301 #define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM] 302 303 /* Override the default value for the offset of the program counter 304 in the sigcontext structure. */ 305 offset = offsetof (struct sigcontext, sc_pc); 306 307 if (SC_PC_OFFSET != offset) 308 { 309 warning (_("\ 310 offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\ 311 Please report this to <bug-gdb@gnu.org>."), 312 offset, SC_PC_OFFSET); 313 } 314 315 SC_PC_OFFSET = offset; 316 317 /* Likewise for the stack pointer. */ 318 offset = offsetof (struct sigcontext, sc_sp); 319 320 if (SC_SP_OFFSET != offset) 321 { 322 warning (_("\ 323 offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\ 324 Please report this to <bug-gdb@gnu.org>."), 325 offset, SC_SP_OFFSET); 326 } 327 328 SC_SP_OFFSET = offset; 329 330 /* And the frame pointer. */ 331 offset = offsetof (struct sigcontext, sc_fp); 332 333 if (SC_FP_OFFSET != offset) 334 { 335 warning (_("\ 336 offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\ 337 Please report this to <bug-gdb@gnu.org>."), 338 offset, SC_FP_OFFSET); 339 } 340 341 SC_FP_OFFSET = offset; 342 343 #endif /* SC_REG_OFFSET */ 344 } 345