Commit | Line | Data |
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da6d8c04 DJ |
1 | /* Low level interface to ptrace, for the remote server for GDB. |
2 | Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002 | |
3 | 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 2 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, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | #include "server.h" | |
58caa3dc | 23 | #include "linux-low.h" |
da6d8c04 | 24 | |
58caa3dc | 25 | #include <sys/wait.h> |
da6d8c04 DJ |
26 | #include <stdio.h> |
27 | #include <sys/param.h> | |
28 | #include <sys/dir.h> | |
29 | #include <sys/ptrace.h> | |
30 | #include <sys/user.h> | |
31 | #include <signal.h> | |
32 | #include <sys/ioctl.h> | |
33 | #include <fcntl.h> | |
d07c63e7 | 34 | #include <string.h> |
0a30fbc4 DJ |
35 | #include <stdlib.h> |
36 | #include <unistd.h> | |
da6d8c04 | 37 | |
d844cde6 | 38 | #define PTRACE_ARG3_TYPE long |
c6ecbae5 | 39 | #define PTRACE_XFER_TYPE long |
da6d8c04 | 40 | |
58caa3dc DJ |
41 | #ifdef HAVE_LINUX_REGSETS |
42 | static int use_regsets_p = 1; | |
43 | #endif | |
44 | ||
da6d8c04 | 45 | extern int errno; |
c6ecbae5 | 46 | |
ce3a066d DJ |
47 | static int inferior_pid; |
48 | ||
da6d8c04 DJ |
49 | /* Start an inferior process and returns its pid. |
50 | ALLARGS is a vector of program-name and args. */ | |
51 | ||
ce3a066d DJ |
52 | static int |
53 | linux_create_inferior (char *program, char **allargs) | |
da6d8c04 DJ |
54 | { |
55 | int pid; | |
56 | ||
57 | pid = fork (); | |
58 | if (pid < 0) | |
59 | perror_with_name ("fork"); | |
60 | ||
61 | if (pid == 0) | |
62 | { | |
63 | ptrace (PTRACE_TRACEME, 0, 0, 0); | |
64 | ||
65 | execv (program, allargs); | |
66 | ||
67 | fprintf (stderr, "Cannot exec %s: %s.\n", program, | |
d07c63e7 | 68 | strerror (errno)); |
da6d8c04 DJ |
69 | fflush (stderr); |
70 | _exit (0177); | |
71 | } | |
72 | ||
ce3a066d DJ |
73 | add_inferior (pid); |
74 | /* FIXME remove */ | |
75 | inferior_pid = pid; | |
76 | return 0; | |
da6d8c04 DJ |
77 | } |
78 | ||
79 | /* Attach to an inferior process. */ | |
80 | ||
ce3a066d DJ |
81 | static int |
82 | linux_attach (int pid) | |
da6d8c04 DJ |
83 | { |
84 | if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0) | |
85 | { | |
86 | fprintf (stderr, "Cannot attach to process %d: %s (%d)\n", pid, | |
87 | errno < sys_nerr ? sys_errlist[errno] : "unknown error", | |
88 | errno); | |
89 | fflush (stderr); | |
90 | _exit (0177); | |
91 | } | |
92 | ||
93 | return 0; | |
94 | } | |
95 | ||
96 | /* Kill the inferior process. Make us have no inferior. */ | |
97 | ||
ce3a066d DJ |
98 | static void |
99 | linux_kill (void) | |
da6d8c04 DJ |
100 | { |
101 | if (inferior_pid == 0) | |
102 | return; | |
103 | ptrace (PTRACE_KILL, inferior_pid, 0, 0); | |
104 | wait (0); | |
ce3a066d | 105 | clear_inferiors (); |
da6d8c04 DJ |
106 | } |
107 | ||
108 | /* Return nonzero if the given thread is still alive. */ | |
ce3a066d DJ |
109 | static int |
110 | linux_thread_alive (int pid) | |
da6d8c04 DJ |
111 | { |
112 | return 1; | |
113 | } | |
114 | ||
115 | /* Wait for process, returns status */ | |
116 | ||
ce3a066d DJ |
117 | static unsigned char |
118 | linux_wait (char *status) | |
da6d8c04 DJ |
119 | { |
120 | int pid; | |
e5f1222d | 121 | int w; |
da6d8c04 DJ |
122 | |
123 | enable_async_io (); | |
e5f1222d | 124 | pid = waitpid (inferior_pid, &w, 0); |
da6d8c04 DJ |
125 | disable_async_io (); |
126 | if (pid != inferior_pid) | |
127 | perror_with_name ("wait"); | |
128 | ||
129 | if (WIFEXITED (w)) | |
130 | { | |
131 | fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w)); | |
132 | *status = 'W'; | |
ce3a066d | 133 | clear_inferiors (); |
da6d8c04 DJ |
134 | return ((unsigned char) WEXITSTATUS (w)); |
135 | } | |
136 | else if (!WIFSTOPPED (w)) | |
137 | { | |
138 | fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w)); | |
ce3a066d | 139 | clear_inferiors (); |
da6d8c04 DJ |
140 | *status = 'X'; |
141 | return ((unsigned char) WTERMSIG (w)); | |
142 | } | |
143 | ||
144 | fetch_inferior_registers (0); | |
145 | ||
146 | *status = 'T'; | |
147 | return ((unsigned char) WSTOPSIG (w)); | |
148 | } | |
149 | ||
150 | /* Resume execution of the inferior process. | |
151 | If STEP is nonzero, single-step it. | |
152 | If SIGNAL is nonzero, give it that signal. */ | |
153 | ||
ce3a066d DJ |
154 | static void |
155 | linux_resume (int step, int signal) | |
da6d8c04 DJ |
156 | { |
157 | errno = 0; | |
158 | ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal); | |
159 | if (errno) | |
160 | perror_with_name ("ptrace"); | |
161 | } | |
162 | ||
c6ecbae5 DJ |
163 | |
164 | #ifdef HAVE_LINUX_USRREGS | |
165 | ||
0a30fbc4 | 166 | #define REGISTER_RAW_SIZE(regno) register_size((regno)) |
da6d8c04 DJ |
167 | |
168 | int | |
0a30fbc4 | 169 | register_addr (int regnum) |
da6d8c04 DJ |
170 | { |
171 | int addr; | |
172 | ||
2ec06d2e | 173 | if (regnum < 0 || regnum >= the_low_target.num_regs) |
da6d8c04 DJ |
174 | error ("Invalid register number %d.", regnum); |
175 | ||
2ec06d2e | 176 | addr = the_low_target.regmap[regnum]; |
da6d8c04 DJ |
177 | if (addr == -1) |
178 | addr = 0; | |
179 | ||
180 | return addr; | |
181 | } | |
182 | ||
58caa3dc | 183 | /* Fetch one register. */ |
da6d8c04 DJ |
184 | static void |
185 | fetch_register (int regno) | |
186 | { | |
187 | CORE_ADDR regaddr; | |
188 | register int i; | |
189 | ||
2ec06d2e | 190 | if (regno >= the_low_target.num_regs) |
0a30fbc4 | 191 | return; |
2ec06d2e | 192 | if ((*the_low_target.cannot_fetch_register) (regno)) |
0a30fbc4 | 193 | return; |
da6d8c04 | 194 | |
0a30fbc4 DJ |
195 | regaddr = register_addr (regno); |
196 | if (regaddr == -1) | |
197 | return; | |
da6d8c04 DJ |
198 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) |
199 | { | |
200 | errno = 0; | |
0a30fbc4 | 201 | *(PTRACE_XFER_TYPE *) (register_data (regno) + i) = |
da6d8c04 DJ |
202 | ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0); |
203 | regaddr += sizeof (PTRACE_XFER_TYPE); | |
204 | if (errno != 0) | |
205 | { | |
206 | /* Warning, not error, in case we are attached; sometimes the | |
207 | kernel doesn't let us at the registers. */ | |
208 | char *err = strerror (errno); | |
209 | char *msg = alloca (strlen (err) + 128); | |
210 | sprintf (msg, "reading register %d: %s", regno, err); | |
211 | error (msg); | |
212 | goto error_exit; | |
213 | } | |
214 | } | |
215 | error_exit:; | |
216 | } | |
217 | ||
218 | /* Fetch all registers, or just one, from the child process. */ | |
58caa3dc DJ |
219 | static void |
220 | usr_fetch_inferior_registers (int regno) | |
da6d8c04 DJ |
221 | { |
222 | if (regno == -1 || regno == 0) | |
2ec06d2e | 223 | for (regno = 0; regno < the_low_target.num_regs; regno++) |
da6d8c04 DJ |
224 | fetch_register (regno); |
225 | else | |
226 | fetch_register (regno); | |
227 | } | |
228 | ||
229 | /* Store our register values back into the inferior. | |
230 | If REGNO is -1, do this for all registers. | |
231 | Otherwise, REGNO specifies which register (so we can save time). */ | |
58caa3dc DJ |
232 | static void |
233 | usr_store_inferior_registers (int regno) | |
da6d8c04 DJ |
234 | { |
235 | CORE_ADDR regaddr; | |
236 | int i; | |
da6d8c04 DJ |
237 | |
238 | if (regno >= 0) | |
239 | { | |
2ec06d2e | 240 | if (regno >= the_low_target.num_regs) |
0a30fbc4 DJ |
241 | return; |
242 | ||
2ec06d2e | 243 | if ((*the_low_target.cannot_store_register) (regno)) |
0a30fbc4 DJ |
244 | return; |
245 | ||
246 | regaddr = register_addr (regno); | |
247 | if (regaddr == -1) | |
da6d8c04 | 248 | return; |
da6d8c04 | 249 | errno = 0; |
c6ecbae5 | 250 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) |
da6d8c04 | 251 | { |
0a30fbc4 DJ |
252 | errno = 0; |
253 | ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, | |
254 | *(int *) (register_data (regno) + i)); | |
da6d8c04 DJ |
255 | if (errno != 0) |
256 | { | |
0a30fbc4 DJ |
257 | /* Warning, not error, in case we are attached; sometimes the |
258 | kernel doesn't let us at the registers. */ | |
259 | char *err = strerror (errno); | |
260 | char *msg = alloca (strlen (err) + 128); | |
261 | sprintf (msg, "writing register %d: %s", | |
262 | regno, err); | |
263 | error (msg); | |
264 | return; | |
da6d8c04 | 265 | } |
0a30fbc4 | 266 | regaddr += sizeof (int); |
da6d8c04 | 267 | } |
da6d8c04 DJ |
268 | } |
269 | else | |
2ec06d2e | 270 | for (regno = 0; regno < the_low_target.num_regs; regno++) |
da6d8c04 DJ |
271 | store_inferior_registers (regno); |
272 | } | |
58caa3dc DJ |
273 | #endif /* HAVE_LINUX_USRREGS */ |
274 | ||
275 | ||
276 | ||
277 | #ifdef HAVE_LINUX_REGSETS | |
278 | ||
279 | static int | |
280 | regsets_fetch_inferior_registers (void) | |
281 | { | |
282 | struct regset_info *regset; | |
283 | ||
284 | regset = target_regsets; | |
285 | ||
286 | while (regset->size >= 0) | |
287 | { | |
288 | void *buf; | |
289 | int res; | |
290 | ||
291 | if (regset->size == 0) | |
292 | { | |
293 | regset ++; | |
294 | continue; | |
295 | } | |
296 | ||
297 | buf = malloc (regset->size); | |
298 | res = ptrace (regset->get_request, inferior_pid, 0, (int) buf); | |
299 | if (res < 0) | |
300 | { | |
301 | if (errno == EIO) | |
302 | { | |
303 | /* If we get EIO on the first regset, do not try regsets again. | |
304 | If we get EIO on a later regset, disable that regset. */ | |
305 | if (regset == target_regsets) | |
306 | { | |
307 | use_regsets_p = 0; | |
308 | return -1; | |
309 | } | |
310 | else | |
311 | { | |
312 | regset->size = 0; | |
313 | continue; | |
314 | } | |
315 | } | |
316 | else | |
317 | { | |
318 | perror ("Warning: ptrace(regsets_fetch_inferior_registers)"); | |
319 | } | |
320 | } | |
321 | regset->store_function (buf); | |
322 | regset ++; | |
323 | } | |
ce3a066d | 324 | return 0; |
58caa3dc DJ |
325 | } |
326 | ||
327 | static int | |
328 | regsets_store_inferior_registers (void) | |
329 | { | |
330 | struct regset_info *regset; | |
331 | ||
332 | regset = target_regsets; | |
333 | ||
334 | while (regset->size >= 0) | |
335 | { | |
336 | void *buf; | |
337 | int res; | |
338 | ||
339 | if (regset->size == 0) | |
340 | { | |
341 | regset ++; | |
342 | continue; | |
343 | } | |
344 | ||
345 | buf = malloc (regset->size); | |
346 | regset->fill_function (buf); | |
347 | res = ptrace (regset->set_request, inferior_pid, 0, (int) buf); | |
348 | if (res < 0) | |
349 | { | |
350 | if (errno == EIO) | |
351 | { | |
352 | /* If we get EIO on the first regset, do not try regsets again. | |
353 | If we get EIO on a later regset, disable that regset. */ | |
354 | if (regset == target_regsets) | |
355 | { | |
356 | use_regsets_p = 0; | |
357 | return -1; | |
358 | } | |
359 | else | |
360 | { | |
361 | regset->size = 0; | |
362 | continue; | |
363 | } | |
364 | } | |
365 | else | |
366 | { | |
ce3a066d | 367 | perror ("Warning: ptrace(regsets_store_inferior_registers)"); |
58caa3dc DJ |
368 | } |
369 | } | |
370 | regset ++; | |
371 | } | |
ce3a066d | 372 | return 0; |
58caa3dc DJ |
373 | } |
374 | ||
375 | #endif /* HAVE_LINUX_REGSETS */ | |
376 | ||
377 | ||
378 | void | |
ce3a066d | 379 | linux_fetch_registers (int regno) |
58caa3dc DJ |
380 | { |
381 | #ifdef HAVE_LINUX_REGSETS | |
382 | if (use_regsets_p) | |
383 | { | |
384 | if (regsets_fetch_inferior_registers () == 0) | |
385 | return; | |
386 | } | |
387 | #endif | |
388 | #ifdef HAVE_LINUX_USRREGS | |
389 | usr_fetch_inferior_registers (regno); | |
390 | #endif | |
391 | } | |
392 | ||
393 | void | |
ce3a066d | 394 | linux_store_registers (int regno) |
58caa3dc DJ |
395 | { |
396 | #ifdef HAVE_LINUX_REGSETS | |
397 | if (use_regsets_p) | |
398 | { | |
399 | if (regsets_store_inferior_registers () == 0) | |
400 | return; | |
401 | } | |
402 | #endif | |
403 | #ifdef HAVE_LINUX_USRREGS | |
404 | usr_store_inferior_registers (regno); | |
405 | #endif | |
406 | } | |
407 | ||
da6d8c04 | 408 | |
da6d8c04 DJ |
409 | /* Copy LEN bytes from inferior's memory starting at MEMADDR |
410 | to debugger memory starting at MYADDR. */ | |
411 | ||
ce3a066d DJ |
412 | static void |
413 | linux_read_memory (CORE_ADDR memaddr, char *myaddr, int len) | |
da6d8c04 DJ |
414 | { |
415 | register int i; | |
416 | /* Round starting address down to longword boundary. */ | |
417 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
418 | /* Round ending address up; get number of longwords that makes. */ | |
419 | register int count | |
420 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) | |
421 | / sizeof (PTRACE_XFER_TYPE); | |
422 | /* Allocate buffer of that many longwords. */ | |
423 | register PTRACE_XFER_TYPE *buffer | |
424 | = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); | |
425 | ||
426 | /* Read all the longwords */ | |
427 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
428 | { | |
d844cde6 | 429 | buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, 0); |
da6d8c04 DJ |
430 | } |
431 | ||
432 | /* Copy appropriate bytes out of the buffer. */ | |
433 | memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len); | |
434 | } | |
435 | ||
436 | /* Copy LEN bytes of data from debugger memory at MYADDR | |
437 | to inferior's memory at MEMADDR. | |
438 | On failure (cannot write the inferior) | |
439 | returns the value of errno. */ | |
440 | ||
ce3a066d DJ |
441 | static int |
442 | linux_write_memory (CORE_ADDR memaddr, char *myaddr, int len) | |
da6d8c04 DJ |
443 | { |
444 | register int i; | |
445 | /* Round starting address down to longword boundary. */ | |
446 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
447 | /* Round ending address up; get number of longwords that makes. */ | |
448 | register int count | |
449 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE); | |
450 | /* Allocate buffer of that many longwords. */ | |
451 | register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); | |
452 | extern int errno; | |
453 | ||
454 | /* Fill start and end extra bytes of buffer with existing memory data. */ | |
455 | ||
d844cde6 DJ |
456 | buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid, |
457 | (PTRACE_ARG3_TYPE) addr, 0); | |
da6d8c04 DJ |
458 | |
459 | if (count > 1) | |
460 | { | |
461 | buffer[count - 1] | |
462 | = ptrace (PTRACE_PEEKTEXT, inferior_pid, | |
d844cde6 DJ |
463 | (PTRACE_ARG3_TYPE) (addr + (count - 1) |
464 | * sizeof (PTRACE_XFER_TYPE)), | |
465 | 0); | |
da6d8c04 DJ |
466 | } |
467 | ||
468 | /* Copy data to be written over corresponding part of buffer */ | |
469 | ||
470 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len); | |
471 | ||
472 | /* Write the entire buffer. */ | |
473 | ||
474 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
475 | { | |
476 | errno = 0; | |
d844cde6 | 477 | ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]); |
da6d8c04 DJ |
478 | if (errno) |
479 | return errno; | |
480 | } | |
481 | ||
482 | return 0; | |
483 | } | |
2f2893d9 DJ |
484 | |
485 | static void | |
486 | linux_look_up_symbols (void) | |
487 | { | |
488 | /* Don't need to look up any symbols yet. */ | |
489 | } | |
490 | ||
da6d8c04 | 491 | \f |
ce3a066d DJ |
492 | static struct target_ops linux_target_ops = { |
493 | linux_create_inferior, | |
494 | linux_attach, | |
495 | linux_kill, | |
496 | linux_thread_alive, | |
497 | linux_resume, | |
498 | linux_wait, | |
499 | linux_fetch_registers, | |
500 | linux_store_registers, | |
501 | linux_read_memory, | |
502 | linux_write_memory, | |
2f2893d9 | 503 | linux_look_up_symbols, |
ce3a066d DJ |
504 | }; |
505 | ||
da6d8c04 DJ |
506 | void |
507 | initialize_low (void) | |
508 | { | |
ce3a066d | 509 | set_target_ops (&linux_target_ops); |
0a30fbc4 | 510 | init_registers (); |
da6d8c04 | 511 | } |