| 1 | /* Low level Unix child interface to ptrace, for GDB when running under Unix. |
| 2 | Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, |
| 3 | 1998, 1999, 2000, 2001, 2002, 2004 |
| 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 2 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, write to the Free Software |
| 20 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| 21 | Boston, MA 02110-1301, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "command.h" |
| 25 | #include "frame.h" |
| 26 | #include "gdbcore.h" |
| 27 | #include "inferior.h" |
| 28 | #include "regcache.h" |
| 29 | #include "target.h" |
| 30 | |
| 31 | #include "gdb_assert.h" |
| 32 | #include "gdb_wait.h" |
| 33 | #include "gdb_string.h" |
| 34 | |
| 35 | #include <sys/param.h> |
| 36 | #include "gdb_dirent.h" |
| 37 | #include <signal.h> |
| 38 | #include <sys/ioctl.h> |
| 39 | |
| 40 | #include "gdb_ptrace.h" |
| 41 | |
| 42 | #ifdef HAVE_SYS_FILE_H |
| 43 | #include <sys/file.h> |
| 44 | #endif |
| 45 | |
| 46 | #if !defined (FETCH_INFERIOR_REGISTERS) |
| 47 | #include <sys/user.h> /* Probably need to poke the user structure */ |
| 48 | #endif /* !FETCH_INFERIOR_REGISTERS */ |
| 49 | |
| 50 | #if !defined (CHILD_XFER_MEMORY) |
| 51 | static void udot_info (char *, int); |
| 52 | #endif |
| 53 | |
| 54 | void _initialize_infptrace (void); |
| 55 | \f |
| 56 | |
| 57 | int |
| 58 | call_ptrace (int request, int pid, PTRACE_ARG3_TYPE addr, int data) |
| 59 | { |
| 60 | return ptrace (request, pid, addr, data); |
| 61 | } |
| 62 | |
| 63 | /* Wait for a process to finish, possibly running a target-specific |
| 64 | hook before returning. */ |
| 65 | |
| 66 | /* NOTE: cagney: 2004-09-29: Dependant on the native configuration, |
| 67 | "hppah-nat.c" may either call this or infttrace.c's implementation |
| 68 | of ptrace_wait. See "hppahpux.mh". */ |
| 69 | |
| 70 | int |
| 71 | ptrace_wait (ptid_t ptid, int *status) |
| 72 | { |
| 73 | int wstate; |
| 74 | |
| 75 | wstate = wait (status); |
| 76 | return wstate; |
| 77 | } |
| 78 | |
| 79 | #ifndef DEPRECATED_KILL_INFERIOR |
| 80 | /* NOTE: cagney/2004-09-12: Instead of definining this macro, code |
| 81 | should call inf_ptrace_target to get a basic ptrace target and then |
| 82 | locally update any necessary methods. See ppcnbsd-nat.c. */ |
| 83 | |
| 84 | void |
| 85 | kill_inferior (void) |
| 86 | { |
| 87 | int status; |
| 88 | int pid = PIDGET (inferior_ptid); |
| 89 | |
| 90 | if (pid == 0) |
| 91 | return; |
| 92 | |
| 93 | /* This once used to call "kill" to kill the inferior just in case |
| 94 | the inferior was still running. As others have noted in the past |
| 95 | (kingdon) there shouldn't be any way to get here if the inferior |
| 96 | is still running -- else there's a major problem elsewere in gdb |
| 97 | and it needs to be fixed. |
| 98 | |
| 99 | The kill call causes problems under hpux10, so it's been removed; |
| 100 | if this causes problems we'll deal with them as they arise. */ |
| 101 | ptrace (PT_KILL, pid, (PTRACE_TYPE_ARG3) 0, 0); |
| 102 | wait (&status); |
| 103 | target_mourn_inferior (); |
| 104 | } |
| 105 | #endif /* DEPRECATED_KILL_INFERIOR */ |
| 106 | |
| 107 | #ifndef DEPRECATED_CHILD_RESUME |
| 108 | /* NOTE: cagney/2004-09-12: Instead of definining this macro, code |
| 109 | should call inf_ptrace_target to get a basic ptrace target and then |
| 110 | locally update any necessary methods. See ppcnbsd-nat.c. */ |
| 111 | |
| 112 | /* Resume execution of the inferior process. |
| 113 | If STEP is nonzero, single-step it. |
| 114 | If SIGNAL is nonzero, give it that signal. */ |
| 115 | |
| 116 | void |
| 117 | child_resume (ptid_t ptid, int step, enum target_signal signal) |
| 118 | { |
| 119 | int request = PT_CONTINUE; |
| 120 | int pid = PIDGET (ptid); |
| 121 | |
| 122 | if (pid == -1) |
| 123 | /* Resume all threads. */ |
| 124 | /* I think this only gets used in the non-threaded case, where "resume |
| 125 | all threads" and "resume inferior_ptid" are the same. */ |
| 126 | pid = PIDGET (inferior_ptid); |
| 127 | |
| 128 | if (step) |
| 129 | { |
| 130 | /* If this system does not support PT_STEP, a higher level |
| 131 | function will have called single_step() to transmute the step |
| 132 | request into a continue request (by setting breakpoints on |
| 133 | all possible successor instructions), so we don't have to |
| 134 | worry about that here. */ |
| 135 | |
| 136 | gdb_assert (!SOFTWARE_SINGLE_STEP_P ()); |
| 137 | request = PT_STEP; |
| 138 | } |
| 139 | |
| 140 | /* An address of (PTRACE_TYPE_ARG3)1 tells ptrace to continue from |
| 141 | where it was. If GDB wanted it to start some other way, we have |
| 142 | already written a new PC value to the child. */ |
| 143 | |
| 144 | errno = 0; |
| 145 | ptrace (request, pid, (PTRACE_TYPE_ARG3)1, target_signal_to_host (signal)); |
| 146 | if (errno != 0) |
| 147 | perror_with_name (("ptrace")); |
| 148 | } |
| 149 | #endif /* DEPRECATED_CHILD_RESUME */ |
| 150 | \f |
| 151 | |
| 152 | /* Start debugging the process whose number is PID. */ |
| 153 | |
| 154 | int |
| 155 | attach (int pid) |
| 156 | { |
| 157 | #ifdef PT_ATTACH |
| 158 | errno = 0; |
| 159 | ptrace (PT_ATTACH, pid, (PTRACE_TYPE_ARG3) 0, 0); |
| 160 | if (errno != 0) |
| 161 | perror_with_name (("ptrace")); |
| 162 | attach_flag = 1; |
| 163 | return pid; |
| 164 | #else |
| 165 | error (_("This system does not support attaching to a process")); |
| 166 | #endif |
| 167 | } |
| 168 | |
| 169 | /* Stop debugging the process whose number is PID and continue it with |
| 170 | signal number SIGNAL. SIGNAL = 0 means just continue it. */ |
| 171 | |
| 172 | void |
| 173 | detach (int signal) |
| 174 | { |
| 175 | #ifdef PT_DETACH |
| 176 | int pid = PIDGET (inferior_ptid); |
| 177 | |
| 178 | errno = 0; |
| 179 | ptrace (PT_DETACH, pid, (PTRACE_TYPE_ARG3) 1, signal); |
| 180 | if (errno != 0) |
| 181 | perror_with_name (("ptrace")); |
| 182 | attach_flag = 0; |
| 183 | #else |
| 184 | error (_("This system does not support detaching from a process")); |
| 185 | #endif |
| 186 | } |
| 187 | \f |
| 188 | |
| 189 | #ifndef FETCH_INFERIOR_REGISTERS |
| 190 | |
| 191 | /* U_REGS_OFFSET is the offset of the registers within the u area. */ |
| 192 | #ifndef U_REGS_OFFSET |
| 193 | |
| 194 | #ifndef offsetof |
| 195 | #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) |
| 196 | #endif |
| 197 | |
| 198 | #define U_REGS_OFFSET \ |
| 199 | ptrace (PT_READ_U, PIDGET (inferior_ptid), \ |
| 200 | (PTRACE_TYPE_ARG3) (offsetof (struct user, u_ar0)), 0) \ |
| 201 | - KERNEL_U_ADDR |
| 202 | #endif |
| 203 | |
| 204 | /* Fetch register REGNUM from the inferior. */ |
| 205 | |
| 206 | static void |
| 207 | fetch_register (int regnum) |
| 208 | { |
| 209 | CORE_ADDR addr; |
| 210 | size_t size; |
| 211 | PTRACE_TYPE_RET *buf; |
| 212 | int tid, i; |
| 213 | |
| 214 | if (CANNOT_FETCH_REGISTER (regnum)) |
| 215 | { |
| 216 | regcache_raw_supply (current_regcache, regnum, NULL); |
| 217 | return; |
| 218 | } |
| 219 | |
| 220 | /* GNU/Linux LWP ID's are process ID's. */ |
| 221 | tid = TIDGET (inferior_ptid); |
| 222 | if (tid == 0) |
| 223 | tid = PIDGET (inferior_ptid); /* Not a threaded program. */ |
| 224 | |
| 225 | /* This isn't really an address. But ptrace thinks of it as one. */ |
| 226 | addr = register_addr (regnum, U_REGS_OFFSET); |
| 227 | size = register_size (current_gdbarch, regnum); |
| 228 | |
| 229 | gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0); |
| 230 | buf = alloca (size); |
| 231 | |
| 232 | /* Read the register contents from the inferior a chuck at the time. */ |
| 233 | for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++) |
| 234 | { |
| 235 | errno = 0; |
| 236 | buf[i] = ptrace (PT_READ_U, tid, (PTRACE_TYPE_ARG3) addr, 0); |
| 237 | if (errno != 0) |
| 238 | error (_("Couldn't read register %s (#%d): %s."), REGISTER_NAME (regnum), |
| 239 | regnum, safe_strerror (errno)); |
| 240 | |
| 241 | addr += sizeof (PTRACE_TYPE_RET); |
| 242 | } |
| 243 | regcache_raw_supply (current_regcache, regnum, buf); |
| 244 | } |
| 245 | |
| 246 | /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this |
| 247 | for all registers. */ |
| 248 | |
| 249 | void |
| 250 | fetch_inferior_registers (int regnum) |
| 251 | { |
| 252 | if (regnum == -1) |
| 253 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 254 | fetch_register (regnum); |
| 255 | else |
| 256 | fetch_register (regnum); |
| 257 | } |
| 258 | |
| 259 | /* Store register REGNUM into the inferior. */ |
| 260 | |
| 261 | static void |
| 262 | store_register (int regnum) |
| 263 | { |
| 264 | CORE_ADDR addr; |
| 265 | size_t size; |
| 266 | PTRACE_TYPE_RET *buf; |
| 267 | int tid, i; |
| 268 | |
| 269 | if (CANNOT_STORE_REGISTER (regnum)) |
| 270 | return; |
| 271 | |
| 272 | /* GNU/Linux LWP ID's are process ID's. */ |
| 273 | tid = TIDGET (inferior_ptid); |
| 274 | if (tid == 0) |
| 275 | tid = PIDGET (inferior_ptid); /* Not a threaded program. */ |
| 276 | |
| 277 | /* This isn't really an address. But ptrace thinks of it as one. */ |
| 278 | addr = register_addr (regnum, U_REGS_OFFSET); |
| 279 | size = register_size (current_gdbarch, regnum); |
| 280 | |
| 281 | gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0); |
| 282 | buf = alloca (size); |
| 283 | |
| 284 | /* Write the register contents into the inferior a chunk at the time. */ |
| 285 | regcache_raw_collect (current_regcache, regnum, buf); |
| 286 | for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++) |
| 287 | { |
| 288 | errno = 0; |
| 289 | ptrace (PT_WRITE_U, tid, (PTRACE_TYPE_ARG3) addr, buf[i]); |
| 290 | if (errno != 0) |
| 291 | error (_("Couldn't write register %s (#%d): %s."), |
| 292 | REGISTER_NAME (regnum), regnum, safe_strerror (errno)); |
| 293 | |
| 294 | addr += sizeof (PTRACE_TYPE_RET); |
| 295 | } |
| 296 | } |
| 297 | |
| 298 | /* Store register REGNUM back into the inferior. If REGNUM is -1, do |
| 299 | this for all registers (including the floating point registers). */ |
| 300 | |
| 301 | void |
| 302 | store_inferior_registers (int regnum) |
| 303 | { |
| 304 | if (regnum == -1) |
| 305 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 306 | store_register (regnum); |
| 307 | else |
| 308 | store_register (regnum); |
| 309 | } |
| 310 | |
| 311 | #endif /* not FETCH_INFERIOR_REGISTERS. */ |
| 312 | \f |
| 313 | |
| 314 | /* Set an upper limit on alloca. */ |
| 315 | #ifndef GDB_MAX_ALLOCA |
| 316 | #define GDB_MAX_ALLOCA 0x1000 |
| 317 | #endif |
| 318 | |
| 319 | #if !defined (CHILD_XFER_MEMORY) |
| 320 | /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory |
| 321 | in the NEW_SUN_PTRACE case. It ought to be straightforward. But |
| 322 | it appears that writing did not write the data that I specified. I |
| 323 | cannot understand where it got the data that it actually did write. */ |
| 324 | |
| 325 | /* Copy LEN bytes to or from inferior's memory starting at MEMADDR to |
| 326 | debugger memory starting at MYADDR. Copy to inferior if WRITE is |
| 327 | nonzero. TARGET is ignored. |
| 328 | |
| 329 | Returns the length copied, which is either the LEN argument or |
| 330 | zero. This xfer function does not do partial moves, since |
| 331 | deprecated_child_ops doesn't allow memory operations to cross below |
| 332 | us in the target stack anyway. */ |
| 333 | |
| 334 | int |
| 335 | child_xfer_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len, int write, |
| 336 | struct mem_attrib *attrib, struct target_ops *target) |
| 337 | { |
| 338 | int i; |
| 339 | /* Round starting address down to longword boundary. */ |
| 340 | CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_TYPE_RET); |
| 341 | /* Round ending address up; get number of longwords that makes. */ |
| 342 | int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1) |
| 343 | / sizeof (PTRACE_TYPE_RET)); |
| 344 | int alloc = count * sizeof (PTRACE_TYPE_RET); |
| 345 | PTRACE_TYPE_RET *buffer; |
| 346 | struct cleanup *old_chain = NULL; |
| 347 | |
| 348 | #ifdef PT_IO |
| 349 | /* OpenBSD 3.1, NetBSD 1.6 and FreeBSD 5.0 have a new PT_IO request |
| 350 | that promises to be much more efficient in reading and writing |
| 351 | data in the traced process's address space. */ |
| 352 | |
| 353 | { |
| 354 | struct ptrace_io_desc piod; |
| 355 | |
| 356 | /* NOTE: We assume that there are no distinct address spaces for |
| 357 | instruction and data. */ |
| 358 | piod.piod_op = write ? PIOD_WRITE_D : PIOD_READ_D; |
| 359 | piod.piod_offs = (void *) memaddr; |
| 360 | piod.piod_addr = myaddr; |
| 361 | piod.piod_len = len; |
| 362 | |
| 363 | if (ptrace (PT_IO, PIDGET (inferior_ptid), (caddr_t) &piod, 0) == -1) |
| 364 | { |
| 365 | /* If the PT_IO request is somehow not supported, fallback on |
| 366 | using PT_WRITE_D/PT_READ_D. Otherwise we will return zero |
| 367 | to indicate failure. */ |
| 368 | if (errno != EINVAL) |
| 369 | return 0; |
| 370 | } |
| 371 | else |
| 372 | { |
| 373 | /* Return the actual number of bytes read or written. */ |
| 374 | return piod.piod_len; |
| 375 | } |
| 376 | } |
| 377 | #endif |
| 378 | |
| 379 | /* Allocate buffer of that many longwords. */ |
| 380 | if (len < GDB_MAX_ALLOCA) |
| 381 | { |
| 382 | buffer = (PTRACE_TYPE_RET *) alloca (alloc); |
| 383 | } |
| 384 | else |
| 385 | { |
| 386 | buffer = (PTRACE_TYPE_RET *) xmalloc (alloc); |
| 387 | old_chain = make_cleanup (xfree, buffer); |
| 388 | } |
| 389 | |
| 390 | if (write) |
| 391 | { |
| 392 | /* Fill start and end extra bytes of buffer with existing memory |
| 393 | data. */ |
| 394 | if (addr != memaddr || len < (int) sizeof (PTRACE_TYPE_RET)) |
| 395 | { |
| 396 | /* Need part of initial word -- fetch it. */ |
| 397 | buffer[0] = ptrace (PT_READ_I, PIDGET (inferior_ptid), |
| 398 | (PTRACE_TYPE_ARG3) addr, 0); |
| 399 | } |
| 400 | |
| 401 | if (count > 1) /* FIXME, avoid if even boundary. */ |
| 402 | { |
| 403 | buffer[count - 1] = |
| 404 | ptrace (PT_READ_I, PIDGET (inferior_ptid), |
| 405 | ((PTRACE_TYPE_ARG3) |
| 406 | (addr + (count - 1) * sizeof (PTRACE_TYPE_RET))), 0); |
| 407 | } |
| 408 | |
| 409 | /* Copy data to be written over corresponding part of buffer. */ |
| 410 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)), |
| 411 | myaddr, len); |
| 412 | |
| 413 | /* Write the entire buffer. */ |
| 414 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET)) |
| 415 | { |
| 416 | errno = 0; |
| 417 | ptrace (PT_WRITE_D, PIDGET (inferior_ptid), |
| 418 | (PTRACE_TYPE_ARG3) addr, buffer[i]); |
| 419 | if (errno) |
| 420 | { |
| 421 | /* Using the appropriate one (I or D) is necessary for |
| 422 | Gould NP1, at least. */ |
| 423 | errno = 0; |
| 424 | ptrace (PT_WRITE_I, PIDGET (inferior_ptid), |
| 425 | (PTRACE_TYPE_ARG3) addr, buffer[i]); |
| 426 | } |
| 427 | if (errno) |
| 428 | return 0; |
| 429 | } |
| 430 | } |
| 431 | else |
| 432 | { |
| 433 | /* Read all the longwords. */ |
| 434 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET)) |
| 435 | { |
| 436 | errno = 0; |
| 437 | buffer[i] = ptrace (PT_READ_I, PIDGET (inferior_ptid), |
| 438 | (PTRACE_TYPE_ARG3) addr, 0); |
| 439 | if (errno) |
| 440 | return 0; |
| 441 | QUIT; |
| 442 | } |
| 443 | |
| 444 | /* Copy appropriate bytes out of the buffer. */ |
| 445 | memcpy (myaddr, |
| 446 | (char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)), |
| 447 | len); |
| 448 | } |
| 449 | |
| 450 | if (old_chain != NULL) |
| 451 | do_cleanups (old_chain); |
| 452 | return len; |
| 453 | } |
| 454 | \f |
| 455 | |
| 456 | static void |
| 457 | udot_info (char *dummy1, int dummy2) |
| 458 | { |
| 459 | #if defined (KERNEL_U_SIZE) |
| 460 | long udot_off; /* Offset into user struct */ |
| 461 | int udot_val; /* Value from user struct at udot_off */ |
| 462 | char mess[128]; /* For messages */ |
| 463 | #endif |
| 464 | |
| 465 | if (!target_has_execution) |
| 466 | { |
| 467 | error (_("The program is not being run.")); |
| 468 | } |
| 469 | |
| 470 | #if !defined (KERNEL_U_SIZE) |
| 471 | |
| 472 | /* Adding support for this command is easy. Typically you just add a |
| 473 | routine, called "kernel_u_size" that returns the size of the user |
| 474 | struct, to the appropriate *-nat.c file and then add to the native |
| 475 | config file "#define KERNEL_U_SIZE kernel_u_size()" */ |
| 476 | error (_("Don't know how large ``struct user'' is in this version of gdb.")); |
| 477 | |
| 478 | #else |
| 479 | |
| 480 | for (udot_off = 0; udot_off < KERNEL_U_SIZE; udot_off += sizeof (udot_val)) |
| 481 | { |
| 482 | if ((udot_off % 24) == 0) |
| 483 | { |
| 484 | if (udot_off > 0) |
| 485 | { |
| 486 | printf_filtered ("\n"); |
| 487 | } |
| 488 | printf_filtered ("%s:", paddr (udot_off)); |
| 489 | } |
| 490 | udot_val = ptrace (PT_READ_U, PIDGET (inferior_ptid), (PTRACE_TYPE_ARG3) udot_off, 0); |
| 491 | if (errno != 0) |
| 492 | { |
| 493 | sprintf (mess, "\nreading user struct at offset 0x%s", |
| 494 | paddr_nz (udot_off)); |
| 495 | perror_with_name (mess); |
| 496 | } |
| 497 | /* Avoid using nonportable (?) "*" in print specs */ |
| 498 | printf_filtered (sizeof (int) == 4 ? " 0x%08x" : " 0x%16x", udot_val); |
| 499 | } |
| 500 | printf_filtered ("\n"); |
| 501 | |
| 502 | #endif |
| 503 | } |
| 504 | #endif /* !defined (CHILD_XFER_MEMORY). */ |
| 505 | \f |
| 506 | |
| 507 | void |
| 508 | _initialize_infptrace (void) |
| 509 | { |
| 510 | #if !defined (CHILD_XFER_MEMORY) |
| 511 | add_info ("udot", udot_info, |
| 512 | _("Print contents of kernel ``struct user'' for current child.")); |
| 513 | #endif |
| 514 | } |