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