| 1 | /* Low level Unix child interface to ptrace, for GDB when running under Unix. |
| 2 | Copyright 1988, 1989, 1990, 1991, 1992 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "frame.h" |
| 22 | #include "inferior.h" |
| 23 | #include "target.h" |
| 24 | |
| 25 | #ifdef USG |
| 26 | #include <sys/types.h> |
| 27 | #endif |
| 28 | |
| 29 | #include <sys/param.h> |
| 30 | #include <sys/dir.h> |
| 31 | #include <signal.h> |
| 32 | #include <sys/ioctl.h> |
| 33 | |
| 34 | #ifndef NO_PTRACE_H |
| 35 | #ifdef PTRACE_IN_WRONG_PLACE |
| 36 | #include <ptrace.h> |
| 37 | #else |
| 38 | #include <sys/ptrace.h> |
| 39 | #endif |
| 40 | #endif /* NO_PTRACE_H */ |
| 41 | |
| 42 | #if !defined (PT_KILL) |
| 43 | #define PT_KILL 8 |
| 44 | #define PT_STEP 9 |
| 45 | #define PT_CONTINUE 7 |
| 46 | #define PT_READ_U 3 |
| 47 | #define PT_WRITE_U 6 |
| 48 | #define PT_READ_I 1 |
| 49 | #define PT_READ_D 2 |
| 50 | #define PT_WRITE_I 4 |
| 51 | #define PT_WRITE_D 5 |
| 52 | #endif /* No PT_KILL. */ |
| 53 | |
| 54 | #ifndef PT_ATTACH |
| 55 | #define PT_ATTACH PTRACE_ATTACH |
| 56 | #endif |
| 57 | #ifndef PT_DETACH |
| 58 | #define PT_DETACH PTRACE_DETACH |
| 59 | #endif |
| 60 | |
| 61 | #include "gdbcore.h" |
| 62 | #ifndef NO_SYS_FILE |
| 63 | #include <sys/file.h> |
| 64 | #endif |
| 65 | #include <sys/stat.h> |
| 66 | |
| 67 | #if defined (FIVE_ARG_PTRACE |
| 68 | /* Deal with HPUX 8.0 braindamage. */ |
| 69 | #define ptrace(a,b,c,d) ptrace(a,b,c,d,0) |
| 70 | #endif |
| 71 | |
| 72 | #if !defined (FETCH_INFERIOR_REGISTERS) |
| 73 | #include <sys/user.h> /* Probably need to poke the user structure */ |
| 74 | #if defined (KERNEL_U_ADDR_BSD) |
| 75 | #include <a.out.h> /* For struct nlist */ |
| 76 | #endif /* KERNEL_U_ADDR_BSD. */ |
| 77 | #endif /* !FETCH_INFERIOR_REGISTERS */ |
| 78 | |
| 79 | \f |
| 80 | /* This function simply calls ptrace with the given arguments. |
| 81 | It exists so that all calls to ptrace are isolated in this |
| 82 | machine-dependent file. */ |
| 83 | int |
| 84 | call_ptrace (request, pid, addr, data) |
| 85 | int request, pid; |
| 86 | PTRACE_ARG3_TYPE addr; |
| 87 | int data; |
| 88 | { |
| 89 | return ptrace (request, pid, addr, data); |
| 90 | } |
| 91 | |
| 92 | #ifdef DEBUG_PTRACE |
| 93 | /* For the rest of the file, use an extra level of indirection */ |
| 94 | /* This lets us breakpoint usefully on call_ptrace. */ |
| 95 | #define ptrace call_ptrace |
| 96 | #endif |
| 97 | |
| 98 | void |
| 99 | kill_inferior () |
| 100 | { |
| 101 | if (inferior_pid == 0) |
| 102 | return; |
| 103 | /* ptrace PT_KILL only works if process is stopped!!! So stop it with |
| 104 | a real signal first, if we can. */ |
| 105 | kill (inferior_pid, SIGKILL); |
| 106 | ptrace (PT_KILL, inferior_pid, (PTRACE_ARG3_TYPE) 0, 0); |
| 107 | wait ((int *)0); |
| 108 | target_mourn_inferior (); |
| 109 | } |
| 110 | |
| 111 | /* Resume execution of the inferior process. |
| 112 | If STEP is nonzero, single-step it. |
| 113 | If SIGNAL is nonzero, give it that signal. */ |
| 114 | |
| 115 | void |
| 116 | child_resume (step, signal) |
| 117 | int step; |
| 118 | int signal; |
| 119 | { |
| 120 | errno = 0; |
| 121 | |
| 122 | /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where |
| 123 | it was. (If GDB wanted it to start some other way, we have already |
| 124 | written a new PC value to the child.) |
| 125 | |
| 126 | If this system does not support PT_STEP, a higher level function will |
| 127 | have called single_step() to transmute the step request into a |
| 128 | continue request (by setting breakpoints on all possible successor |
| 129 | instructions), so we don't have to worry about that here. */ |
| 130 | |
| 131 | if (step) |
| 132 | ptrace (PT_STEP, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal); |
| 133 | else |
| 134 | ptrace (PT_CONTINUE, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal); |
| 135 | |
| 136 | if (errno) |
| 137 | perror_with_name ("ptrace"); |
| 138 | } |
| 139 | \f |
| 140 | #ifdef ATTACH_DETACH |
| 141 | /* Start debugging the process whose number is PID. */ |
| 142 | int |
| 143 | attach (pid) |
| 144 | int pid; |
| 145 | { |
| 146 | errno = 0; |
| 147 | ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 0, 0); |
| 148 | if (errno) |
| 149 | perror_with_name ("ptrace"); |
| 150 | attach_flag = 1; |
| 151 | return pid; |
| 152 | } |
| 153 | |
| 154 | /* Stop debugging the process whose number is PID |
| 155 | and continue it with signal number SIGNAL. |
| 156 | SIGNAL = 0 means just continue it. */ |
| 157 | |
| 158 | void |
| 159 | detach (signal) |
| 160 | int signal; |
| 161 | { |
| 162 | errno = 0; |
| 163 | ptrace (PT_DETACH, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal); |
| 164 | if (errno) |
| 165 | perror_with_name ("ptrace"); |
| 166 | attach_flag = 0; |
| 167 | } |
| 168 | #endif /* ATTACH_DETACH */ |
| 169 | \f |
| 170 | #if !defined (FETCH_INFERIOR_REGISTERS) |
| 171 | |
| 172 | /* KERNEL_U_ADDR is the amount to subtract from u.u_ar0 |
| 173 | to get the offset in the core file of the register values. */ |
| 174 | #if defined (KERNEL_U_ADDR_BSD) |
| 175 | /* Get kernel_u_addr using BSD-style nlist(). */ |
| 176 | CORE_ADDR kernel_u_addr; |
| 177 | |
| 178 | void |
| 179 | _initialize_kernel_u_addr () |
| 180 | { |
| 181 | struct nlist names[2]; |
| 182 | |
| 183 | names[0].n_un.n_name = "_u"; |
| 184 | names[1].n_un.n_name = NULL; |
| 185 | if (nlist ("/vmunix", names) == 0) |
| 186 | kernel_u_addr = names[0].n_value; |
| 187 | else |
| 188 | fatal ("Unable to get kernel u area address."); |
| 189 | } |
| 190 | #endif /* KERNEL_U_ADDR_BSD. */ |
| 191 | |
| 192 | #if defined (KERNEL_U_ADDR_HPUX) |
| 193 | /* Get kernel_u_addr using HPUX-style nlist(). */ |
| 194 | CORE_ADDR kernel_u_addr; |
| 195 | |
| 196 | struct hpnlist { |
| 197 | char * n_name; |
| 198 | long n_value; |
| 199 | unsigned char n_type; |
| 200 | unsigned char n_length; |
| 201 | short n_almod; |
| 202 | short n_unused; |
| 203 | }; |
| 204 | static struct hpnlist nl[] = {{ "_u", -1, }, { (char *) 0, }}; |
| 205 | |
| 206 | /* read the value of the u area from the hp-ux kernel */ |
| 207 | void _initialize_kernel_u_addr () |
| 208 | { |
| 209 | nlist ("/hp-ux", &nl); |
| 210 | kernel_u_addr = nl[0].n_value; |
| 211 | } |
| 212 | #endif /* KERNEL_U_ADDR_HPUX. */ |
| 213 | |
| 214 | #if !defined (offsetof) |
| 215 | #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) |
| 216 | #endif |
| 217 | |
| 218 | /* U_REGS_OFFSET is the offset of the registers within the u area. */ |
| 219 | #if !defined (U_REGS_OFFSET) |
| 220 | #define U_REGS_OFFSET \ |
| 221 | ptrace (PT_READ_U, inferior_pid, \ |
| 222 | (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \ |
| 223 | - KERNEL_U_ADDR |
| 224 | #endif |
| 225 | |
| 226 | /* Registers we shouldn't try to fetch. */ |
| 227 | #if !defined (CANNOT_FETCH_REGISTER) |
| 228 | #define CANNOT_FETCH_REGISTER(regno) 0 |
| 229 | #endif |
| 230 | |
| 231 | /* Fetch one register. */ |
| 232 | |
| 233 | static void |
| 234 | fetch_register (regno) |
| 235 | int regno; |
| 236 | { |
| 237 | register unsigned int regaddr; |
| 238 | char buf[MAX_REGISTER_RAW_SIZE]; |
| 239 | char mess[128]; /* For messages */ |
| 240 | register int i; |
| 241 | |
| 242 | /* Offset of registers within the u area. */ |
| 243 | unsigned int offset; |
| 244 | |
| 245 | if (CANNOT_FETCH_REGISTER (regno)) |
| 246 | { |
| 247 | bzero (buf, REGISTER_RAW_SIZE (regno)); /* Supply zeroes */ |
| 248 | supply_register (regno, buf); |
| 249 | return; |
| 250 | } |
| 251 | |
| 252 | offset = U_REGS_OFFSET; |
| 253 | |
| 254 | regaddr = register_addr (regno, offset); |
| 255 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int)) |
| 256 | { |
| 257 | errno = 0; |
| 258 | *(int *) &buf[i] = ptrace (PT_READ_U, inferior_pid, |
| 259 | (PTRACE_ARG3_TYPE) regaddr, 0); |
| 260 | regaddr += sizeof (int); |
| 261 | if (errno != 0) |
| 262 | { |
| 263 | sprintf (mess, "reading register %s (#%d)", reg_names[regno], regno); |
| 264 | perror_with_name (mess); |
| 265 | } |
| 266 | } |
| 267 | supply_register (regno, buf); |
| 268 | } |
| 269 | |
| 270 | |
| 271 | /* Fetch all registers, or just one, from the child process. */ |
| 272 | |
| 273 | void |
| 274 | fetch_inferior_registers (regno) |
| 275 | int regno; |
| 276 | { |
| 277 | if (regno == -1) |
| 278 | for (regno = 0; regno < NUM_REGS; regno++) |
| 279 | fetch_register (regno); |
| 280 | else |
| 281 | fetch_register (regno); |
| 282 | } |
| 283 | |
| 284 | /* Registers we shouldn't try to store. */ |
| 285 | #if !defined (CANNOT_STORE_REGISTER) |
| 286 | #define CANNOT_STORE_REGISTER(regno) 0 |
| 287 | #endif |
| 288 | |
| 289 | /* Store our register values back into the inferior. |
| 290 | If REGNO is -1, do this for all registers. |
| 291 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 292 | |
| 293 | void |
| 294 | store_inferior_registers (regno) |
| 295 | int regno; |
| 296 | { |
| 297 | register unsigned int regaddr; |
| 298 | char buf[80]; |
| 299 | extern char registers[]; |
| 300 | register int i; |
| 301 | |
| 302 | unsigned int offset = U_REGS_OFFSET; |
| 303 | |
| 304 | if (regno >= 0) |
| 305 | { |
| 306 | regaddr = register_addr (regno, offset); |
| 307 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int)) |
| 308 | { |
| 309 | errno = 0; |
| 310 | ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, |
| 311 | *(int *) ®isters[REGISTER_BYTE (regno) + i]); |
| 312 | if (errno != 0) |
| 313 | { |
| 314 | sprintf (buf, "writing register number %d(%d)", regno, i); |
| 315 | perror_with_name (buf); |
| 316 | } |
| 317 | regaddr += sizeof(int); |
| 318 | } |
| 319 | } |
| 320 | else |
| 321 | { |
| 322 | for (regno = 0; regno < NUM_REGS; regno++) |
| 323 | { |
| 324 | if (CANNOT_STORE_REGISTER (regno)) |
| 325 | continue; |
| 326 | regaddr = register_addr (regno, offset); |
| 327 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int)) |
| 328 | { |
| 329 | errno = 0; |
| 330 | ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, |
| 331 | *(int *) ®isters[REGISTER_BYTE (regno) + i]); |
| 332 | if (errno != 0) |
| 333 | { |
| 334 | sprintf (buf, "writing register number %d(%d)", regno, i); |
| 335 | perror_with_name (buf); |
| 336 | } |
| 337 | regaddr += sizeof(int); |
| 338 | } |
| 339 | } |
| 340 | } |
| 341 | } |
| 342 | #endif /* !defined (FETCH_INFERIOR_REGISTERS). */ |
| 343 | \f |
| 344 | /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory |
| 345 | in the NEW_SUN_PTRACE case. |
| 346 | It ought to be straightforward. But it appears that writing did |
| 347 | not write the data that I specified. I cannot understand where |
| 348 | it got the data that it actually did write. */ |
| 349 | |
| 350 | /* Copy LEN bytes to or from inferior's memory starting at MEMADDR |
| 351 | to debugger memory starting at MYADDR. Copy to inferior if |
| 352 | WRITE is nonzero. |
| 353 | |
| 354 | Returns the length copied, which is either the LEN argument or zero. |
| 355 | This xfer function does not do partial moves, since child_ops |
| 356 | doesn't allow memory operations to cross below us in the target stack |
| 357 | anyway. */ |
| 358 | |
| 359 | int |
| 360 | child_xfer_memory (memaddr, myaddr, len, write, target) |
| 361 | CORE_ADDR memaddr; |
| 362 | char *myaddr; |
| 363 | int len; |
| 364 | int write; |
| 365 | struct target_ops *target; /* ignored */ |
| 366 | { |
| 367 | register int i; |
| 368 | /* Round starting address down to longword boundary. */ |
| 369 | register CORE_ADDR addr = memaddr & - sizeof (int); |
| 370 | /* Round ending address up; get number of longwords that makes. */ |
| 371 | register int count |
| 372 | = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int); |
| 373 | /* Allocate buffer of that many longwords. */ |
| 374 | register int *buffer = (int *) alloca (count * sizeof (int)); |
| 375 | |
| 376 | if (write) |
| 377 | { |
| 378 | /* Fill start and end extra bytes of buffer with existing memory data. */ |
| 379 | |
| 380 | if (addr != memaddr || len < (int)sizeof (int)) { |
| 381 | /* Need part of initial word -- fetch it. */ |
| 382 | buffer[0] = ptrace (PT_READ_I, inferior_pid, (PTRACE_ARG3_TYPE) addr, |
| 383 | 0); |
| 384 | } |
| 385 | |
| 386 | if (count > 1) /* FIXME, avoid if even boundary */ |
| 387 | { |
| 388 | buffer[count - 1] |
| 389 | = ptrace (PT_READ_I, inferior_pid, |
| 390 | (PTRACE_ARG3_TYPE) (addr + (count - 1) * sizeof (int)), |
| 391 | 0); |
| 392 | } |
| 393 | |
| 394 | /* Copy data to be written over corresponding part of buffer */ |
| 395 | |
| 396 | memcpy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len); |
| 397 | |
| 398 | /* Write the entire buffer. */ |
| 399 | |
| 400 | for (i = 0; i < count; i++, addr += sizeof (int)) |
| 401 | { |
| 402 | errno = 0; |
| 403 | ptrace (PT_WRITE_D, inferior_pid, (PTRACE_ARG3_TYPE) addr, |
| 404 | buffer[i]); |
| 405 | if (errno) |
| 406 | { |
| 407 | /* Using the appropriate one (I or D) is necessary for |
| 408 | Gould NP1, at least. */ |
| 409 | errno = 0; |
| 410 | ptrace (PT_WRITE_I, inferior_pid, (PTRACE_ARG3_TYPE) addr, |
| 411 | buffer[i]); |
| 412 | } |
| 413 | if (errno) |
| 414 | return 0; |
| 415 | } |
| 416 | } |
| 417 | else |
| 418 | { |
| 419 | /* Read all the longwords */ |
| 420 | for (i = 0; i < count; i++, addr += sizeof (int)) |
| 421 | { |
| 422 | errno = 0; |
| 423 | buffer[i] = ptrace (PT_READ_I, inferior_pid, |
| 424 | (PTRACE_ARG3_TYPE) addr, 0); |
| 425 | if (errno) |
| 426 | return 0; |
| 427 | QUIT; |
| 428 | } |
| 429 | |
| 430 | /* Copy appropriate bytes out of the buffer. */ |
| 431 | memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len); |
| 432 | } |
| 433 | return len; |
| 434 | } |