| 1 | /* Motorola m68k native support for GNU/Linux. |
| 2 | |
| 3 | Copyright (C) 1996-2020 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 "frame.h" |
| 22 | #include "inferior.h" |
| 23 | #include "language.h" |
| 24 | #include "gdbcore.h" |
| 25 | #include "regcache.h" |
| 26 | #include "target.h" |
| 27 | #include "linux-nat.h" |
| 28 | #include "gdbarch.h" |
| 29 | |
| 30 | #include "m68k-tdep.h" |
| 31 | |
| 32 | #include <sys/dir.h> |
| 33 | #include <signal.h> |
| 34 | #include "nat/gdb_ptrace.h" |
| 35 | #include <sys/user.h> |
| 36 | #include <sys/ioctl.h> |
| 37 | #include <fcntl.h> |
| 38 | #include <sys/procfs.h> |
| 39 | |
| 40 | #ifdef HAVE_SYS_REG_H |
| 41 | #include <sys/reg.h> |
| 42 | #endif |
| 43 | |
| 44 | #include <sys/file.h> |
| 45 | #include <sys/stat.h> |
| 46 | |
| 47 | #include "floatformat.h" |
| 48 | |
| 49 | /* Prototypes for supply_gregset etc. */ |
| 50 | #include "gregset.h" |
| 51 | |
| 52 | /* Defines ps_err_e, struct ps_prochandle. */ |
| 53 | #include "gdb_proc_service.h" |
| 54 | |
| 55 | #include "inf-ptrace.h" |
| 56 | |
| 57 | #ifndef PTRACE_GET_THREAD_AREA |
| 58 | #define PTRACE_GET_THREAD_AREA 25 |
| 59 | #endif |
| 60 | \f |
| 61 | |
| 62 | class m68k_linux_nat_target final : public linux_nat_target |
| 63 | { |
| 64 | public: |
| 65 | /* Add our register access methods. */ |
| 66 | void fetch_registers (struct regcache *, int) override; |
| 67 | void store_registers (struct regcache *, int) override; |
| 68 | }; |
| 69 | |
| 70 | static m68k_linux_nat_target the_m68k_linux_nat_target; |
| 71 | |
| 72 | /* This table must line up with gdbarch_register_name in "m68k-tdep.c". */ |
| 73 | static const int regmap[] = |
| 74 | { |
| 75 | PT_D0, PT_D1, PT_D2, PT_D3, PT_D4, PT_D5, PT_D6, PT_D7, |
| 76 | PT_A0, PT_A1, PT_A2, PT_A3, PT_A4, PT_A5, PT_A6, PT_USP, |
| 77 | PT_SR, PT_PC, |
| 78 | /* PT_FP0, ..., PT_FP7 */ |
| 79 | 21, 24, 27, 30, 33, 36, 39, 42, |
| 80 | /* PT_FPCR, PT_FPSR, PT_FPIAR */ |
| 81 | 45, 46, 47 |
| 82 | }; |
| 83 | |
| 84 | /* Which ptrace request retrieves which registers? |
| 85 | These apply to the corresponding SET requests as well. */ |
| 86 | #define NUM_GREGS (18) |
| 87 | #define MAX_NUM_REGS (NUM_GREGS + 11) |
| 88 | |
| 89 | static int |
| 90 | getregs_supplies (int regno) |
| 91 | { |
| 92 | return 0 <= regno && regno < NUM_GREGS; |
| 93 | } |
| 94 | |
| 95 | static int |
| 96 | getfpregs_supplies (int regno) |
| 97 | { |
| 98 | return M68K_FP0_REGNUM <= regno && regno <= M68K_FPI_REGNUM; |
| 99 | } |
| 100 | |
| 101 | /* Does the current host support the GETREGS request? */ |
| 102 | static int have_ptrace_getregs = |
| 103 | #ifdef HAVE_PTRACE_GETREGS |
| 104 | 1 |
| 105 | #else |
| 106 | 0 |
| 107 | #endif |
| 108 | ; |
| 109 | |
| 110 | \f |
| 111 | |
| 112 | /* Fetching registers directly from the U area, one at a time. */ |
| 113 | |
| 114 | /* Fetch one register. */ |
| 115 | |
| 116 | static void |
| 117 | fetch_register (struct regcache *regcache, int regno) |
| 118 | { |
| 119 | struct gdbarch *gdbarch = regcache->arch (); |
| 120 | long regaddr, val; |
| 121 | int i; |
| 122 | gdb_byte buf[M68K_MAX_REGISTER_SIZE]; |
| 123 | pid_t tid = get_ptrace_pid (regcache->ptid ()); |
| 124 | |
| 125 | regaddr = 4 * regmap[regno]; |
| 126 | for (i = 0; i < register_size (gdbarch, regno); i += sizeof (long)) |
| 127 | { |
| 128 | errno = 0; |
| 129 | val = ptrace (PTRACE_PEEKUSER, tid, regaddr, 0); |
| 130 | memcpy (&buf[i], &val, sizeof (long)); |
| 131 | regaddr += sizeof (long); |
| 132 | if (errno != 0) |
| 133 | error (_("Couldn't read register %s (#%d): %s."), |
| 134 | gdbarch_register_name (gdbarch, regno), |
| 135 | regno, safe_strerror (errno)); |
| 136 | } |
| 137 | regcache->raw_supply (regno, buf); |
| 138 | } |
| 139 | |
| 140 | /* Fetch register values from the inferior. |
| 141 | If REGNO is negative, do this for all registers. |
| 142 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 143 | |
| 144 | static void |
| 145 | old_fetch_inferior_registers (struct regcache *regcache, int regno) |
| 146 | { |
| 147 | if (regno >= 0) |
| 148 | { |
| 149 | fetch_register (regcache, regno); |
| 150 | } |
| 151 | else |
| 152 | { |
| 153 | for (regno = 0; |
| 154 | regno < gdbarch_num_regs (regcache->arch ()); |
| 155 | regno++) |
| 156 | { |
| 157 | fetch_register (regcache, regno); |
| 158 | } |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | /* Store one register. */ |
| 163 | |
| 164 | static void |
| 165 | store_register (const struct regcache *regcache, int regno) |
| 166 | { |
| 167 | struct gdbarch *gdbarch = regcache->arch (); |
| 168 | long regaddr, val; |
| 169 | int i; |
| 170 | gdb_byte buf[M68K_MAX_REGISTER_SIZE]; |
| 171 | pid_t tid = get_ptrace_pid (regcache->ptid ()); |
| 172 | |
| 173 | regaddr = 4 * regmap[regno]; |
| 174 | |
| 175 | /* Put the contents of regno into a local buffer. */ |
| 176 | regcache->raw_collect (regno, buf); |
| 177 | |
| 178 | /* Store the local buffer into the inferior a chunk at the time. */ |
| 179 | for (i = 0; i < register_size (gdbarch, regno); i += sizeof (long)) |
| 180 | { |
| 181 | errno = 0; |
| 182 | memcpy (&val, &buf[i], sizeof (long)); |
| 183 | ptrace (PTRACE_POKEUSER, tid, regaddr, val); |
| 184 | regaddr += sizeof (long); |
| 185 | if (errno != 0) |
| 186 | error (_("Couldn't write register %s (#%d): %s."), |
| 187 | gdbarch_register_name (gdbarch, regno), |
| 188 | regno, safe_strerror (errno)); |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | /* Store our register values back into the inferior. |
| 193 | If REGNO is negative, do this for all registers. |
| 194 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 195 | |
| 196 | static void |
| 197 | old_store_inferior_registers (const struct regcache *regcache, int regno) |
| 198 | { |
| 199 | if (regno >= 0) |
| 200 | { |
| 201 | store_register (regcache, regno); |
| 202 | } |
| 203 | else |
| 204 | { |
| 205 | for (regno = 0; |
| 206 | regno < gdbarch_num_regs (regcache->arch ()); |
| 207 | regno++) |
| 208 | { |
| 209 | store_register (regcache, regno); |
| 210 | } |
| 211 | } |
| 212 | } |
| 213 | \f |
| 214 | /* Given a pointer to a general register set in /proc format |
| 215 | (elf_gregset_t *), unpack the register contents and supply |
| 216 | them as gdb's idea of the current register values. */ |
| 217 | |
| 218 | void |
| 219 | supply_gregset (struct regcache *regcache, const elf_gregset_t *gregsetp) |
| 220 | { |
| 221 | struct gdbarch *gdbarch = regcache->arch (); |
| 222 | const elf_greg_t *regp = (const elf_greg_t *) gregsetp; |
| 223 | int regi; |
| 224 | |
| 225 | for (regi = M68K_D0_REGNUM; |
| 226 | regi <= gdbarch_sp_regnum (gdbarch); |
| 227 | regi++) |
| 228 | regcache->raw_supply (regi, ®p[regmap[regi]]); |
| 229 | regcache->raw_supply (gdbarch_ps_regnum (gdbarch), ®p[PT_SR]); |
| 230 | regcache->raw_supply (gdbarch_pc_regnum (gdbarch), ®p[PT_PC]); |
| 231 | } |
| 232 | |
| 233 | /* Fill register REGNO (if it is a general-purpose register) in |
| 234 | *GREGSETPS with the value in GDB's register array. If REGNO is -1, |
| 235 | do this for all registers. */ |
| 236 | void |
| 237 | fill_gregset (const struct regcache *regcache, |
| 238 | elf_gregset_t *gregsetp, int regno) |
| 239 | { |
| 240 | elf_greg_t *regp = (elf_greg_t *) gregsetp; |
| 241 | int i; |
| 242 | |
| 243 | for (i = 0; i < NUM_GREGS; i++) |
| 244 | if (regno == -1 || regno == i) |
| 245 | regcache->raw_collect (i, regp + regmap[i]); |
| 246 | } |
| 247 | |
| 248 | #ifdef HAVE_PTRACE_GETREGS |
| 249 | |
| 250 | /* Fetch all general-purpose registers from process/thread TID and |
| 251 | store their values in GDB's register array. */ |
| 252 | |
| 253 | static void |
| 254 | fetch_regs (struct regcache *regcache, int tid) |
| 255 | { |
| 256 | elf_gregset_t regs; |
| 257 | |
| 258 | if (ptrace (PTRACE_GETREGS, tid, 0, (int) ®s) < 0) |
| 259 | { |
| 260 | if (errno == EIO) |
| 261 | { |
| 262 | /* The kernel we're running on doesn't support the GETREGS |
| 263 | request. Reset `have_ptrace_getregs'. */ |
| 264 | have_ptrace_getregs = 0; |
| 265 | return; |
| 266 | } |
| 267 | |
| 268 | perror_with_name (_("Couldn't get registers")); |
| 269 | } |
| 270 | |
| 271 | supply_gregset (regcache, (const elf_gregset_t *) ®s); |
| 272 | } |
| 273 | |
| 274 | /* Store all valid general-purpose registers in GDB's register array |
| 275 | into the process/thread specified by TID. */ |
| 276 | |
| 277 | static void |
| 278 | store_regs (const struct regcache *regcache, int tid, int regno) |
| 279 | { |
| 280 | elf_gregset_t regs; |
| 281 | |
| 282 | if (ptrace (PTRACE_GETREGS, tid, 0, (int) ®s) < 0) |
| 283 | perror_with_name (_("Couldn't get registers")); |
| 284 | |
| 285 | fill_gregset (regcache, ®s, regno); |
| 286 | |
| 287 | if (ptrace (PTRACE_SETREGS, tid, 0, (int) ®s) < 0) |
| 288 | perror_with_name (_("Couldn't write registers")); |
| 289 | } |
| 290 | |
| 291 | #else |
| 292 | |
| 293 | static void fetch_regs (struct regcache *regcache, int tid) |
| 294 | { |
| 295 | } |
| 296 | |
| 297 | static void store_regs (const struct regcache *regcache, int tid, int regno) |
| 298 | { |
| 299 | } |
| 300 | |
| 301 | #endif |
| 302 | |
| 303 | \f |
| 304 | /* Transfering floating-point registers between GDB, inferiors and cores. */ |
| 305 | |
| 306 | /* What is the address of fpN within the floating-point register set F? */ |
| 307 | #define FPREG_ADDR(f, n) (&(f)->fpregs[(n) * 3]) |
| 308 | |
| 309 | /* Fill GDB's register array with the floating-point register values in |
| 310 | *FPREGSETP. */ |
| 311 | |
| 312 | void |
| 313 | supply_fpregset (struct regcache *regcache, const elf_fpregset_t *fpregsetp) |
| 314 | { |
| 315 | struct gdbarch *gdbarch = regcache->arch (); |
| 316 | int regi; |
| 317 | |
| 318 | for (regi = gdbarch_fp0_regnum (gdbarch); |
| 319 | regi < gdbarch_fp0_regnum (gdbarch) + 8; regi++) |
| 320 | regcache->raw_supply |
| 321 | (regi, FPREG_ADDR (fpregsetp, regi - gdbarch_fp0_regnum (gdbarch))); |
| 322 | regcache->raw_supply (M68K_FPC_REGNUM, &fpregsetp->fpcntl[0]); |
| 323 | regcache->raw_supply (M68K_FPS_REGNUM, &fpregsetp->fpcntl[1]); |
| 324 | regcache->raw_supply (M68K_FPI_REGNUM, &fpregsetp->fpcntl[2]); |
| 325 | } |
| 326 | |
| 327 | /* Fill register REGNO (if it is a floating-point register) in |
| 328 | *FPREGSETP with the value in GDB's register array. If REGNO is -1, |
| 329 | do this for all registers. */ |
| 330 | |
| 331 | void |
| 332 | fill_fpregset (const struct regcache *regcache, |
| 333 | elf_fpregset_t *fpregsetp, int regno) |
| 334 | { |
| 335 | struct gdbarch *gdbarch = regcache->arch (); |
| 336 | int i; |
| 337 | |
| 338 | /* Fill in the floating-point registers. */ |
| 339 | for (i = gdbarch_fp0_regnum (gdbarch); |
| 340 | i < gdbarch_fp0_regnum (gdbarch) + 8; i++) |
| 341 | if (regno == -1 || regno == i) |
| 342 | regcache->raw_collect |
| 343 | (i, FPREG_ADDR (fpregsetp, i - gdbarch_fp0_regnum (gdbarch))); |
| 344 | |
| 345 | /* Fill in the floating-point control registers. */ |
| 346 | for (i = M68K_FPC_REGNUM; i <= M68K_FPI_REGNUM; i++) |
| 347 | if (regno == -1 || regno == i) |
| 348 | regcache->raw_collect (i, &fpregsetp->fpcntl[i - M68K_FPC_REGNUM]); |
| 349 | } |
| 350 | |
| 351 | #ifdef HAVE_PTRACE_GETREGS |
| 352 | |
| 353 | /* Fetch all floating-point registers from process/thread TID and store |
| 354 | thier values in GDB's register array. */ |
| 355 | |
| 356 | static void |
| 357 | fetch_fpregs (struct regcache *regcache, int tid) |
| 358 | { |
| 359 | elf_fpregset_t fpregs; |
| 360 | |
| 361 | if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0) |
| 362 | perror_with_name (_("Couldn't get floating point status")); |
| 363 | |
| 364 | supply_fpregset (regcache, (const elf_fpregset_t *) &fpregs); |
| 365 | } |
| 366 | |
| 367 | /* Store all valid floating-point registers in GDB's register array |
| 368 | into the process/thread specified by TID. */ |
| 369 | |
| 370 | static void |
| 371 | store_fpregs (const struct regcache *regcache, int tid, int regno) |
| 372 | { |
| 373 | elf_fpregset_t fpregs; |
| 374 | |
| 375 | if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0) |
| 376 | perror_with_name (_("Couldn't get floating point status")); |
| 377 | |
| 378 | fill_fpregset (regcache, &fpregs, regno); |
| 379 | |
| 380 | if (ptrace (PTRACE_SETFPREGS, tid, 0, (int) &fpregs) < 0) |
| 381 | perror_with_name (_("Couldn't write floating point status")); |
| 382 | } |
| 383 | |
| 384 | #else |
| 385 | |
| 386 | static void fetch_fpregs (struct regcache *regcache, int tid) |
| 387 | { |
| 388 | } |
| 389 | |
| 390 | static void store_fpregs (const struct regcache *regcache, int tid, int regno) |
| 391 | { |
| 392 | } |
| 393 | |
| 394 | #endif |
| 395 | \f |
| 396 | /* Transferring arbitrary registers between GDB and inferior. */ |
| 397 | |
| 398 | /* Fetch register REGNO from the child process. If REGNO is -1, do |
| 399 | this for all registers (including the floating point and SSE |
| 400 | registers). */ |
| 401 | |
| 402 | void |
| 403 | m68k_linux_nat_target::fetch_registers (struct regcache *regcache, int regno) |
| 404 | { |
| 405 | pid_t tid; |
| 406 | |
| 407 | /* Use the old method of peeking around in `struct user' if the |
| 408 | GETREGS request isn't available. */ |
| 409 | if (! have_ptrace_getregs) |
| 410 | { |
| 411 | old_fetch_inferior_registers (regcache, regno); |
| 412 | return; |
| 413 | } |
| 414 | |
| 415 | tid = get_ptrace_pid (regcache->ptid ()); |
| 416 | |
| 417 | /* Use the PTRACE_GETFPXREGS request whenever possible, since it |
| 418 | transfers more registers in one system call, and we'll cache the |
| 419 | results. But remember that fetch_fpxregs can fail, and return |
| 420 | zero. */ |
| 421 | if (regno == -1) |
| 422 | { |
| 423 | fetch_regs (regcache, tid); |
| 424 | |
| 425 | /* The call above might reset `have_ptrace_getregs'. */ |
| 426 | if (! have_ptrace_getregs) |
| 427 | { |
| 428 | old_fetch_inferior_registers (regcache, -1); |
| 429 | return; |
| 430 | } |
| 431 | |
| 432 | fetch_fpregs (regcache, tid); |
| 433 | return; |
| 434 | } |
| 435 | |
| 436 | if (getregs_supplies (regno)) |
| 437 | { |
| 438 | fetch_regs (regcache, tid); |
| 439 | return; |
| 440 | } |
| 441 | |
| 442 | if (getfpregs_supplies (regno)) |
| 443 | { |
| 444 | fetch_fpregs (regcache, tid); |
| 445 | return; |
| 446 | } |
| 447 | |
| 448 | internal_error (__FILE__, __LINE__, |
| 449 | _("Got request for bad register number %d."), regno); |
| 450 | } |
| 451 | |
| 452 | /* Store register REGNO back into the child process. If REGNO is -1, |
| 453 | do this for all registers (including the floating point and SSE |
| 454 | registers). */ |
| 455 | void |
| 456 | m68k_linux_nat_target::store_registers (struct regcache *regcache, int regno) |
| 457 | { |
| 458 | pid_t tid; |
| 459 | |
| 460 | /* Use the old method of poking around in `struct user' if the |
| 461 | SETREGS request isn't available. */ |
| 462 | if (! have_ptrace_getregs) |
| 463 | { |
| 464 | old_store_inferior_registers (regcache, regno); |
| 465 | return; |
| 466 | } |
| 467 | |
| 468 | tid = get_ptrace_pid (regcache->ptid ()); |
| 469 | |
| 470 | /* Use the PTRACE_SETFPREGS requests whenever possible, since it |
| 471 | transfers more registers in one system call. But remember that |
| 472 | store_fpregs can fail, and return zero. */ |
| 473 | if (regno == -1) |
| 474 | { |
| 475 | store_regs (regcache, tid, regno); |
| 476 | store_fpregs (regcache, tid, regno); |
| 477 | return; |
| 478 | } |
| 479 | |
| 480 | if (getregs_supplies (regno)) |
| 481 | { |
| 482 | store_regs (regcache, tid, regno); |
| 483 | return; |
| 484 | } |
| 485 | |
| 486 | if (getfpregs_supplies (regno)) |
| 487 | { |
| 488 | store_fpregs (regcache, tid, regno); |
| 489 | return; |
| 490 | } |
| 491 | |
| 492 | internal_error (__FILE__, __LINE__, |
| 493 | _("Got request to store bad register number %d."), regno); |
| 494 | } |
| 495 | \f |
| 496 | |
| 497 | /* Fetch the thread-local storage pointer for libthread_db. */ |
| 498 | |
| 499 | ps_err_e |
| 500 | ps_get_thread_area (struct ps_prochandle *ph, |
| 501 | lwpid_t lwpid, int idx, void **base) |
| 502 | { |
| 503 | if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) < 0) |
| 504 | return PS_ERR; |
| 505 | |
| 506 | /* IDX is the bias from the thread pointer to the beginning of the |
| 507 | thread descriptor. It has to be subtracted due to implementation |
| 508 | quirks in libthread_db. */ |
| 509 | *base = (char *) *base - idx; |
| 510 | |
| 511 | return PS_OK; |
| 512 | } |
| 513 | |
| 514 | void |
| 515 | _initialize_m68k_linux_nat (void) |
| 516 | { |
| 517 | /* Register the target. */ |
| 518 | linux_target = &the_m68k_linux_nat_target; |
| 519 | add_inf_child_target (&the_m68k_linux_nat_target); |
| 520 | } |