| 1 | /* Low level Unix child interface to ptrace, for GDB when running under Unix. |
| 2 | Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "frame.h" |
| 22 | #include "inferior.h" |
| 23 | #include "target.h" |
| 24 | #include "gdb_string.h" |
| 25 | #include "wait.h" |
| 26 | #include "command.h" |
| 27 | |
| 28 | #ifdef USG |
| 29 | #include <sys/types.h> |
| 30 | #endif |
| 31 | |
| 32 | #include <sys/param.h> |
| 33 | #include <sys/dir.h> |
| 34 | #include <signal.h> |
| 35 | #include <sys/ioctl.h> |
| 36 | |
| 37 | #ifndef NO_PTRACE_H |
| 38 | #ifdef PTRACE_IN_WRONG_PLACE |
| 39 | #include <ptrace.h> |
| 40 | #else |
| 41 | #include <sys/ptrace.h> |
| 42 | #endif |
| 43 | #endif /* NO_PTRACE_H */ |
| 44 | |
| 45 | #if !defined (PT_READ_I) |
| 46 | #define PT_READ_I 1 /* Read word from text space */ |
| 47 | #endif |
| 48 | #if !defined (PT_READ_D) |
| 49 | #define PT_READ_D 2 /* Read word from data space */ |
| 50 | #endif |
| 51 | #if !defined (PT_READ_U) |
| 52 | #define PT_READ_U 3 /* Read word from kernel user struct */ |
| 53 | #endif |
| 54 | #if !defined (PT_WRITE_I) |
| 55 | #define PT_WRITE_I 4 /* Write word to text space */ |
| 56 | #endif |
| 57 | #if !defined (PT_WRITE_D) |
| 58 | #define PT_WRITE_D 5 /* Write word to data space */ |
| 59 | #endif |
| 60 | #if !defined (PT_WRITE_U) |
| 61 | #define PT_WRITE_U 6 /* Write word to kernel user struct */ |
| 62 | #endif |
| 63 | #if !defined (PT_CONTINUE) |
| 64 | #define PT_CONTINUE 7 /* Continue after signal */ |
| 65 | #endif |
| 66 | #if !defined (PT_STEP) |
| 67 | #define PT_STEP 9 /* Set flag for single stepping */ |
| 68 | #endif |
| 69 | #if !defined (PT_KILL) |
| 70 | #define PT_KILL 8 /* Send child a SIGKILL signal */ |
| 71 | #endif |
| 72 | |
| 73 | #ifndef PT_ATTACH |
| 74 | #define PT_ATTACH PTRACE_ATTACH |
| 75 | #endif |
| 76 | #ifndef PT_DETACH |
| 77 | #define PT_DETACH PTRACE_DETACH |
| 78 | #endif |
| 79 | |
| 80 | #include "gdbcore.h" |
| 81 | #ifndef NO_SYS_FILE |
| 82 | #include <sys/file.h> |
| 83 | #endif |
| 84 | #if 0 |
| 85 | /* Don't think this is used anymore. On the sequent (not sure whether it's |
| 86 | dynix or ptx or both), it is included unconditionally by sys/user.h and |
| 87 | not protected against multiple inclusion. */ |
| 88 | #include "gdb_stat.h" |
| 89 | #endif |
| 90 | |
| 91 | #if !defined (FETCH_INFERIOR_REGISTERS) |
| 92 | #include <sys/user.h> /* Probably need to poke the user structure */ |
| 93 | #if defined (KERNEL_U_ADDR_BSD) |
| 94 | #include <a.out.h> /* For struct nlist */ |
| 95 | #endif /* KERNEL_U_ADDR_BSD. */ |
| 96 | #endif /* !FETCH_INFERIOR_REGISTERS */ |
| 97 | |
| 98 | \f |
| 99 | /* This function simply calls ptrace with the given arguments. |
| 100 | It exists so that all calls to ptrace are isolated in this |
| 101 | machine-dependent file. */ |
| 102 | int |
| 103 | call_ptrace (request, pid, addr, data) |
| 104 | int request, pid; |
| 105 | PTRACE_ARG3_TYPE addr; |
| 106 | int data; |
| 107 | { |
| 108 | return ptrace (request, pid, addr, data |
| 109 | #if defined (FIVE_ARG_PTRACE) |
| 110 | /* Deal with HPUX 8.0 braindamage. We never use the |
| 111 | calls which require the fifth argument. */ |
| 112 | , 0 |
| 113 | #endif |
| 114 | ); |
| 115 | } |
| 116 | |
| 117 | #if defined (DEBUG_PTRACE) || defined (FIVE_ARG_PTRACE) |
| 118 | /* For the rest of the file, use an extra level of indirection */ |
| 119 | /* This lets us breakpoint usefully on call_ptrace. */ |
| 120 | #define ptrace call_ptrace |
| 121 | #endif |
| 122 | |
| 123 | void |
| 124 | kill_inferior () |
| 125 | { |
| 126 | if (inferior_pid == 0) |
| 127 | return; |
| 128 | /* ptrace PT_KILL only works if process is stopped!!! So stop it with |
| 129 | a real signal first, if we can. FIXME: This is bogus. When the inferior |
| 130 | is not stopped, GDB should just be waiting for it. Either the following |
| 131 | line is unecessary, or there is some problem elsewhere in GDB which |
| 132 | causes us to get here when the inferior is not stopped. */ |
| 133 | kill (inferior_pid, SIGKILL); |
| 134 | ptrace (PT_KILL, inferior_pid, (PTRACE_ARG3_TYPE) 0, 0); |
| 135 | wait ((int *)0); |
| 136 | target_mourn_inferior (); |
| 137 | } |
| 138 | |
| 139 | #ifndef CHILD_RESUME |
| 140 | |
| 141 | /* Resume execution of the inferior process. |
| 142 | If STEP is nonzero, single-step it. |
| 143 | If SIGNAL is nonzero, give it that signal. */ |
| 144 | |
| 145 | void |
| 146 | child_resume (pid, step, signal) |
| 147 | int pid; |
| 148 | int step; |
| 149 | enum target_signal signal; |
| 150 | { |
| 151 | errno = 0; |
| 152 | |
| 153 | if (pid == -1) |
| 154 | /* Resume all threads. */ |
| 155 | /* I think this only gets used in the non-threaded case, where "resume |
| 156 | all threads" and "resume inferior_pid" are the same. */ |
| 157 | pid = inferior_pid; |
| 158 | |
| 159 | /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where |
| 160 | it was. (If GDB wanted it to start some other way, we have already |
| 161 | written a new PC value to the child.) |
| 162 | |
| 163 | If this system does not support PT_STEP, a higher level function will |
| 164 | have called single_step() to transmute the step request into a |
| 165 | continue request (by setting breakpoints on all possible successor |
| 166 | instructions), so we don't have to worry about that here. */ |
| 167 | |
| 168 | if (step) |
| 169 | ptrace (PT_STEP, pid, (PTRACE_ARG3_TYPE) 1, |
| 170 | target_signal_to_host (signal)); |
| 171 | else |
| 172 | ptrace (PT_CONTINUE, pid, (PTRACE_ARG3_TYPE) 1, |
| 173 | target_signal_to_host (signal)); |
| 174 | |
| 175 | if (errno) |
| 176 | perror_with_name ("ptrace"); |
| 177 | } |
| 178 | #endif /* CHILD_RESUME */ |
| 179 | |
| 180 | \f |
| 181 | #ifdef ATTACH_DETACH |
| 182 | /* Start debugging the process whose number is PID. */ |
| 183 | int |
| 184 | attach (pid) |
| 185 | int pid; |
| 186 | { |
| 187 | errno = 0; |
| 188 | ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 0, 0); |
| 189 | if (errno) |
| 190 | perror_with_name ("ptrace"); |
| 191 | attach_flag = 1; |
| 192 | return pid; |
| 193 | } |
| 194 | |
| 195 | /* Stop debugging the process whose number is PID |
| 196 | and continue it with signal number SIGNAL. |
| 197 | SIGNAL = 0 means just continue it. */ |
| 198 | |
| 199 | void |
| 200 | detach (signal) |
| 201 | int signal; |
| 202 | { |
| 203 | errno = 0; |
| 204 | ptrace (PT_DETACH, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal); |
| 205 | if (errno) |
| 206 | perror_with_name ("ptrace"); |
| 207 | attach_flag = 0; |
| 208 | } |
| 209 | #endif /* ATTACH_DETACH */ |
| 210 | \f |
| 211 | /* Default the type of the ptrace transfer to int. */ |
| 212 | #ifndef PTRACE_XFER_TYPE |
| 213 | #define PTRACE_XFER_TYPE int |
| 214 | #endif |
| 215 | |
| 216 | /* KERNEL_U_ADDR is the amount to subtract from u.u_ar0 |
| 217 | to get the offset in the core file of the register values. */ |
| 218 | #if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS) |
| 219 | /* Get kernel_u_addr using BSD-style nlist(). */ |
| 220 | CORE_ADDR kernel_u_addr; |
| 221 | #endif /* KERNEL_U_ADDR_BSD. */ |
| 222 | |
| 223 | void |
| 224 | _initialize_kernel_u_addr () |
| 225 | { |
| 226 | #if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS) |
| 227 | struct nlist names[2]; |
| 228 | |
| 229 | names[0].n_un.n_name = "_u"; |
| 230 | names[1].n_un.n_name = NULL; |
| 231 | if (nlist ("/vmunix", names) == 0) |
| 232 | kernel_u_addr = names[0].n_value; |
| 233 | else |
| 234 | fatal ("Unable to get kernel u area address."); |
| 235 | #endif /* KERNEL_U_ADDR_BSD. */ |
| 236 | } |
| 237 | |
| 238 | #if !defined (FETCH_INFERIOR_REGISTERS) |
| 239 | |
| 240 | #if !defined (offsetof) |
| 241 | #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) |
| 242 | #endif |
| 243 | |
| 244 | /* U_REGS_OFFSET is the offset of the registers within the u area. */ |
| 245 | #if !defined (U_REGS_OFFSET) |
| 246 | #define U_REGS_OFFSET \ |
| 247 | ptrace (PT_READ_U, inferior_pid, \ |
| 248 | (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \ |
| 249 | - KERNEL_U_ADDR |
| 250 | #endif |
| 251 | |
| 252 | /* Registers we shouldn't try to fetch. */ |
| 253 | #if !defined (CANNOT_FETCH_REGISTER) |
| 254 | #define CANNOT_FETCH_REGISTER(regno) 0 |
| 255 | #endif |
| 256 | |
| 257 | /* Fetch one register. */ |
| 258 | |
| 259 | static void |
| 260 | fetch_register (regno) |
| 261 | int regno; |
| 262 | { |
| 263 | /* This isn't really an address. But ptrace thinks of it as one. */ |
| 264 | CORE_ADDR regaddr; |
| 265 | char buf[MAX_REGISTER_RAW_SIZE]; |
| 266 | char mess[128]; /* For messages */ |
| 267 | register int i; |
| 268 | |
| 269 | /* Offset of registers within the u area. */ |
| 270 | unsigned int offset; |
| 271 | |
| 272 | if (CANNOT_FETCH_REGISTER (regno)) |
| 273 | { |
| 274 | memset (buf, '\0', REGISTER_RAW_SIZE (regno)); /* Supply zeroes */ |
| 275 | supply_register (regno, buf); |
| 276 | return; |
| 277 | } |
| 278 | |
| 279 | offset = U_REGS_OFFSET; |
| 280 | |
| 281 | regaddr = register_addr (regno, offset); |
| 282 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) |
| 283 | { |
| 284 | errno = 0; |
| 285 | *(PTRACE_XFER_TYPE *) &buf[i] = ptrace (PT_READ_U, inferior_pid, |
| 286 | (PTRACE_ARG3_TYPE) regaddr, 0); |
| 287 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 288 | if (errno != 0) |
| 289 | { |
| 290 | sprintf (mess, "reading register %s (#%d)", reg_names[regno], regno); |
| 291 | perror_with_name (mess); |
| 292 | } |
| 293 | } |
| 294 | supply_register (regno, buf); |
| 295 | } |
| 296 | |
| 297 | |
| 298 | /* Fetch all registers, or just one, from the child process. */ |
| 299 | |
| 300 | void |
| 301 | fetch_inferior_registers (regno) |
| 302 | int regno; |
| 303 | { |
| 304 | int numregs; |
| 305 | |
| 306 | if (regno == -1) |
| 307 | { |
| 308 | numregs = ARCH_NUM_REGS; |
| 309 | for (regno = 0; regno < numregs; regno++) |
| 310 | fetch_register (regno); |
| 311 | } |
| 312 | else |
| 313 | fetch_register (regno); |
| 314 | } |
| 315 | |
| 316 | /* Registers we shouldn't try to store. */ |
| 317 | #if !defined (CANNOT_STORE_REGISTER) |
| 318 | #define CANNOT_STORE_REGISTER(regno) 0 |
| 319 | #endif |
| 320 | |
| 321 | /* Store our register values back into the inferior. |
| 322 | If REGNO is -1, do this for all registers. |
| 323 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 324 | |
| 325 | void |
| 326 | store_inferior_registers (regno) |
| 327 | int regno; |
| 328 | { |
| 329 | /* This isn't really an address. But ptrace thinks of it as one. */ |
| 330 | CORE_ADDR regaddr; |
| 331 | char buf[80]; |
| 332 | register int i, numregs; |
| 333 | |
| 334 | unsigned int offset = U_REGS_OFFSET; |
| 335 | |
| 336 | if (regno >= 0) |
| 337 | { |
| 338 | regaddr = register_addr (regno, offset); |
| 339 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(PTRACE_XFER_TYPE)) |
| 340 | { |
| 341 | errno = 0; |
| 342 | ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, |
| 343 | *(PTRACE_XFER_TYPE *) ®isters[REGISTER_BYTE (regno) + i]); |
| 344 | if (errno != 0) |
| 345 | { |
| 346 | sprintf (buf, "writing register number %d(%d)", regno, i); |
| 347 | perror_with_name (buf); |
| 348 | } |
| 349 | regaddr += sizeof(PTRACE_XFER_TYPE); |
| 350 | } |
| 351 | } |
| 352 | else |
| 353 | { |
| 354 | numregs = ARCH_NUM_REGS; |
| 355 | for (regno = 0; regno < numregs; regno++) |
| 356 | { |
| 357 | if (CANNOT_STORE_REGISTER (regno)) |
| 358 | continue; |
| 359 | regaddr = register_addr (regno, offset); |
| 360 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(PTRACE_XFER_TYPE)) |
| 361 | { |
| 362 | errno = 0; |
| 363 | ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, |
| 364 | *(PTRACE_XFER_TYPE *) ®isters[REGISTER_BYTE (regno) + i]); |
| 365 | if (errno != 0) |
| 366 | { |
| 367 | sprintf (buf, "writing register number %d(%d)", regno, i); |
| 368 | perror_with_name (buf); |
| 369 | } |
| 370 | regaddr += sizeof(PTRACE_XFER_TYPE); |
| 371 | } |
| 372 | } |
| 373 | } |
| 374 | } |
| 375 | #endif /* !defined (FETCH_INFERIOR_REGISTERS). */ |
| 376 | \f |
| 377 | |
| 378 | #if !defined (CHILD_XFER_MEMORY) |
| 379 | /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory |
| 380 | in the NEW_SUN_PTRACE case. |
| 381 | It ought to be straightforward. But it appears that writing did |
| 382 | not write the data that I specified. I cannot understand where |
| 383 | it got the data that it actually did write. */ |
| 384 | |
| 385 | /* Copy LEN bytes to or from inferior's memory starting at MEMADDR |
| 386 | to debugger memory starting at MYADDR. Copy to inferior if |
| 387 | WRITE is nonzero. |
| 388 | |
| 389 | Returns the length copied, which is either the LEN argument or zero. |
| 390 | This xfer function does not do partial moves, since child_ops |
| 391 | doesn't allow memory operations to cross below us in the target stack |
| 392 | anyway. */ |
| 393 | |
| 394 | int |
| 395 | child_xfer_memory (memaddr, myaddr, len, write, target) |
| 396 | CORE_ADDR memaddr; |
| 397 | char *myaddr; |
| 398 | int len; |
| 399 | int write; |
| 400 | struct target_ops *target; /* ignored */ |
| 401 | { |
| 402 | register int i; |
| 403 | /* Round starting address down to longword boundary. */ |
| 404 | register CORE_ADDR addr = memaddr & - sizeof (PTRACE_XFER_TYPE); |
| 405 | /* Round ending address up; get number of longwords that makes. */ |
| 406 | register int count |
| 407 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 408 | / sizeof (PTRACE_XFER_TYPE); |
| 409 | /* Allocate buffer of that many longwords. */ |
| 410 | register PTRACE_XFER_TYPE *buffer |
| 411 | = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| 412 | |
| 413 | if (write) |
| 414 | { |
| 415 | /* Fill start and end extra bytes of buffer with existing memory data. */ |
| 416 | |
| 417 | if (addr != memaddr || len < (int) sizeof (PTRACE_XFER_TYPE)) { |
| 418 | /* Need part of initial word -- fetch it. */ |
| 419 | buffer[0] = ptrace (PT_READ_I, inferior_pid, (PTRACE_ARG3_TYPE) addr, |
| 420 | 0); |
| 421 | } |
| 422 | |
| 423 | if (count > 1) /* FIXME, avoid if even boundary */ |
| 424 | { |
| 425 | buffer[count - 1] |
| 426 | = ptrace (PT_READ_I, inferior_pid, |
| 427 | ((PTRACE_ARG3_TYPE) |
| 428 | (addr + (count - 1) * sizeof (PTRACE_XFER_TYPE))), |
| 429 | 0); |
| 430 | } |
| 431 | |
| 432 | /* Copy data to be written over corresponding part of buffer */ |
| 433 | |
| 434 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), |
| 435 | myaddr, |
| 436 | len); |
| 437 | |
| 438 | /* Write the entire buffer. */ |
| 439 | |
| 440 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 441 | { |
| 442 | errno = 0; |
| 443 | ptrace (PT_WRITE_D, inferior_pid, (PTRACE_ARG3_TYPE) addr, |
| 444 | buffer[i]); |
| 445 | if (errno) |
| 446 | { |
| 447 | /* Using the appropriate one (I or D) is necessary for |
| 448 | Gould NP1, at least. */ |
| 449 | errno = 0; |
| 450 | ptrace (PT_WRITE_I, inferior_pid, (PTRACE_ARG3_TYPE) addr, |
| 451 | buffer[i]); |
| 452 | } |
| 453 | if (errno) |
| 454 | return 0; |
| 455 | } |
| 456 | } |
| 457 | else |
| 458 | { |
| 459 | /* Read all the longwords */ |
| 460 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 461 | { |
| 462 | errno = 0; |
| 463 | buffer[i] = ptrace (PT_READ_I, inferior_pid, |
| 464 | (PTRACE_ARG3_TYPE) addr, 0); |
| 465 | if (errno) |
| 466 | return 0; |
| 467 | QUIT; |
| 468 | } |
| 469 | |
| 470 | /* Copy appropriate bytes out of the buffer. */ |
| 471 | memcpy (myaddr, |
| 472 | (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), |
| 473 | len); |
| 474 | } |
| 475 | return len; |
| 476 | } |
| 477 | |
| 478 | \f |
| 479 | static void |
| 480 | udot_info () |
| 481 | { |
| 482 | int udot_off; /* Offset into user struct */ |
| 483 | int udot_val; /* Value from user struct at udot_off */ |
| 484 | char mess[128]; /* For messages */ |
| 485 | |
| 486 | if (!target_has_execution) |
| 487 | { |
| 488 | error ("The program is not being run."); |
| 489 | } |
| 490 | |
| 491 | #if !defined (KERNEL_U_SIZE) |
| 492 | |
| 493 | /* Adding support for this command is easy. Typically you just add a |
| 494 | routine, called "kernel_u_size" that returns the size of the user |
| 495 | struct, to the appropriate *-nat.c file and then add to the native |
| 496 | config file "#define KERNEL_U_SIZE kernel_u_size()" */ |
| 497 | error ("Don't know how large ``struct user'' is in this version of gdb."); |
| 498 | |
| 499 | #else |
| 500 | |
| 501 | for (udot_off = 0; udot_off < KERNEL_U_SIZE; udot_off += sizeof (udot_val)) |
| 502 | { |
| 503 | if ((udot_off % 24) == 0) |
| 504 | { |
| 505 | if (udot_off > 0) |
| 506 | { |
| 507 | printf_filtered ("\n"); |
| 508 | } |
| 509 | printf_filtered ("%04x:", udot_off); |
| 510 | } |
| 511 | udot_val = ptrace (PT_READ_U, inferior_pid, (PTRACE_ARG3_TYPE) udot_off, 0); |
| 512 | if (errno != 0) |
| 513 | { |
| 514 | sprintf (mess, "\nreading user struct at offset 0x%x", udot_off); |
| 515 | perror_with_name (mess); |
| 516 | } |
| 517 | /* Avoid using nonportable (?) "*" in print specs */ |
| 518 | printf_filtered (sizeof (int) == 4 ? " 0x%08x" : " 0x%16x", udot_val); |
| 519 | } |
| 520 | printf_filtered ("\n"); |
| 521 | |
| 522 | #endif |
| 523 | } |
| 524 | #endif /* !defined (CHILD_XFER_MEMORY). */ |
| 525 | |
| 526 | \f |
| 527 | void |
| 528 | _initialize_infptrace () |
| 529 | { |
| 530 | #if !defined (CHILD_XFER_MEMORY) |
| 531 | add_info ("udot", udot_info, |
| 532 | "Print contents of kernel ``struct user'' for current child."); |
| 533 | #endif |
| 534 | } |