Commit | Line | Data |
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2c4a536d | 1 | /* Low-level child interface to ptrace. |
5bf970f9 | 2 | |
6aba47ca | 3 | Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, |
0fb0cc75 | 4 | 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2007, 2008, 2009 |
8785ced0 | 5 | Free Software Foundation, Inc. |
5bf970f9 AC |
6 | |
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 11 | the Free Software Foundation; either version 3 of the License, or |
5bf970f9 AC |
12 | (at your option) any later version. |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
5bf970f9 AC |
21 | |
22 | #include "defs.h" | |
5bf970f9 | 23 | #include "command.h" |
2c4a536d MK |
24 | #include "inferior.h" |
25 | #include "inflow.h" | |
5bf970f9 | 26 | #include "gdbcore.h" |
8785ced0 | 27 | #include "regcache.h" |
5bf970f9 | 28 | |
8785ced0 | 29 | #include "gdb_assert.h" |
2c4a536d MK |
30 | #include "gdb_string.h" |
31 | #include "gdb_ptrace.h" | |
34a17005 | 32 | #include "gdb_wait.h" |
5bf970f9 AC |
33 | #include <signal.h> |
34 | ||
2c4a536d | 35 | #include "inf-child.h" |
af990527 | 36 | #include "gdbthread.h" |
2c4a536d | 37 | |
c7c14b96 MK |
38 | \f |
39 | ||
735f54b4 MK |
40 | #ifdef PT_GET_PROCESS_STATE |
41 | ||
42 | static int | |
ee057212 | 43 | inf_ptrace_follow_fork (struct target_ops *ops, int follow_child) |
735f54b4 MK |
44 | { |
45 | pid_t pid, fpid; | |
46 | ptrace_state_t pe; | |
4e1c45ea | 47 | struct thread_info *last_tp = NULL; |
735f54b4 MK |
48 | |
49 | /* FIXME: kettenis/20050720: This stuff should really be passed as | |
50 | an argument by our caller. */ | |
51 | { | |
52 | ptid_t ptid; | |
53 | struct target_waitstatus status; | |
54 | ||
55 | get_last_target_status (&ptid, &status); | |
56 | gdb_assert (status.kind == TARGET_WAITKIND_FORKED); | |
57 | ||
58 | pid = ptid_get_pid (ptid); | |
4e1c45ea | 59 | last_tp = find_thread_pid (ptid); |
735f54b4 MK |
60 | } |
61 | ||
62 | if (ptrace (PT_GET_PROCESS_STATE, pid, | |
63 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) | |
64 | perror_with_name (("ptrace")); | |
65 | ||
66 | gdb_assert (pe.pe_report_event == PTRACE_FORK); | |
67 | fpid = pe.pe_other_pid; | |
68 | ||
69 | if (follow_child) | |
70 | { | |
4e1c45ea PA |
71 | /* Copy user stepping state to the new inferior thread. */ |
72 | struct breakpoint *step_resume_breakpoint = last_tp->step_resume_breakpoint; | |
73 | CORE_ADDR step_range_start = last_tp->step_range_start; | |
74 | CORE_ADDR step_range_end = last_tp->step_range_end; | |
75 | struct frame_id step_frame_id = last_tp->step_frame_id; | |
77435e4c PA |
76 | int attach_flag = find_inferior_pid (pid)->attach_flag; |
77 | struct inferior *inf; | |
4e1c45ea PA |
78 | struct thread_info *tp; |
79 | ||
80 | /* Otherwise, deleting the parent would get rid of this | |
81 | breakpoint. */ | |
82 | last_tp->step_resume_breakpoint = NULL; | |
83 | ||
84 | /* Before detaching from the parent, remove all breakpoints from | |
85 | it. */ | |
77435e4c | 86 | remove_breakpoints (); |
735f54b4 MK |
87 | |
88 | if (ptrace (PT_DETACH, pid, (PTRACE_TYPE_ARG3)1, 0) == -1) | |
89 | perror_with_name (("ptrace")); | |
4e1c45ea | 90 | |
7f9f62ba PA |
91 | /* Switch inferior_ptid out of the parent's way. */ |
92 | inferior_ptid = pid_to_ptid (fpid); | |
93 | ||
4e1c45ea | 94 | /* Delete the parent. */ |
7f9f62ba | 95 | detach_inferior (pid); |
4e1c45ea PA |
96 | |
97 | /* Add the child. */ | |
77435e4c PA |
98 | inf = add_inferior (fpid); |
99 | inf->attach_flag = attach_flag; | |
4e1c45ea PA |
100 | tp = add_thread_silent (inferior_ptid); |
101 | ||
102 | tp->step_resume_breakpoint = step_resume_breakpoint; | |
103 | tp->step_range_start = step_range_start; | |
104 | tp->step_range_end = step_range_end; | |
105 | tp->step_frame_id = step_frame_id; | |
106 | ||
107 | /* Reset breakpoints in the child as appropriate. */ | |
108 | follow_inferior_reset_breakpoints (); | |
735f54b4 MK |
109 | } |
110 | else | |
111 | { | |
112 | inferior_ptid = pid_to_ptid (pid); | |
113 | detach_breakpoints (fpid); | |
114 | ||
115 | if (ptrace (PT_DETACH, fpid, (PTRACE_TYPE_ARG3)1, 0) == -1) | |
116 | perror_with_name (("ptrace")); | |
7f9f62ba | 117 | detach_inferior (pid); |
735f54b4 MK |
118 | } |
119 | ||
120 | return 0; | |
121 | } | |
122 | ||
123 | #endif /* PT_GET_PROCESS_STATE */ | |
124 | \f | |
125 | ||
4b8a1a28 | 126 | /* Prepare to be traced. */ |
5bf970f9 AC |
127 | |
128 | static void | |
c7c14b96 | 129 | inf_ptrace_me (void) |
5bf970f9 | 130 | { |
c7c14b96 | 131 | /* "Trace me, Dr. Memory!" */ |
4b8a1a28 | 132 | ptrace (PT_TRACE_ME, 0, (PTRACE_TYPE_ARG3)0, 0); |
5bf970f9 AC |
133 | } |
134 | ||
136d6dae VP |
135 | /* Start a new inferior Unix child process. EXEC_FILE is the file to |
136 | run, ALLARGS is a string containing the arguments to the program. | |
137 | ENV is the environment vector to pass. If FROM_TTY is non-zero, be | |
138 | chatty about it. */ | |
5bf970f9 AC |
139 | |
140 | static void | |
136d6dae VP |
141 | inf_ptrace_create_inferior (struct target_ops *ops, |
142 | char *exec_file, char *allargs, char **env, | |
143 | int from_tty) | |
5bf970f9 | 144 | { |
136d6dae VP |
145 | int pid; |
146 | ||
147 | pid = fork_inferior (exec_file, allargs, env, inf_ptrace_me, NULL, | |
148 | NULL, NULL); | |
149 | ||
150 | push_target (ops); | |
5bf970f9 | 151 | |
c7c14b96 MK |
152 | /* On some targets, there must be some explicit synchronization |
153 | between the parent and child processes after the debugger | |
154 | forks, and before the child execs the debuggee program. This | |
155 | call basically gives permission for the child to exec. */ | |
5bf970f9 | 156 | |
c7c14b96 | 157 | target_acknowledge_created_inferior (pid); |
5bf970f9 | 158 | |
c7c14b96 MK |
159 | /* START_INFERIOR_TRAPS_EXPECTED is defined in inferior.h, and will |
160 | be 1 or 2 depending on whether we're starting without or with a | |
161 | shell. */ | |
162 | startup_inferior (START_INFERIOR_TRAPS_EXPECTED); | |
163 | ||
164 | /* On some targets, there must be some explicit actions taken after | |
165 | the inferior has been started up. */ | |
166 | target_post_startup_inferior (pid_to_ptid (pid)); | |
5bf970f9 AC |
167 | } |
168 | ||
e4ef629d MK |
169 | #ifdef PT_GET_PROCESS_STATE |
170 | ||
171 | static void | |
172 | inf_ptrace_post_startup_inferior (ptid_t pid) | |
173 | { | |
174 | ptrace_event_t pe; | |
175 | ||
176 | /* Set the initial event mask. */ | |
177 | memset (&pe, 0, sizeof pe); | |
178 | pe.pe_set_event |= PTRACE_FORK; | |
179 | if (ptrace (PT_SET_EVENT_MASK, ptid_get_pid (pid), | |
180 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) | |
181 | perror_with_name (("ptrace")); | |
182 | } | |
183 | ||
184 | #endif | |
185 | ||
4b8a1a28 MK |
186 | /* Clean up a rotting corpse of an inferior after it died. */ |
187 | ||
c7c14b96 | 188 | static void |
136d6dae | 189 | inf_ptrace_mourn_inferior (struct target_ops *ops) |
5bf970f9 | 190 | { |
4b8a1a28 MK |
191 | int status; |
192 | ||
193 | /* Wait just one more time to collect the inferior's exit status. | |
f010475d | 194 | Do not check whether this succeeds though, since we may be |
4b8a1a28 | 195 | dealing with a process that we attached to. Such a process will |
3d450bdd | 196 | only report its exit status to its original parent. */ |
4b8a1a28 MK |
197 | waitpid (ptid_get_pid (inferior_ptid), &status, 0); |
198 | ||
136d6dae | 199 | unpush_target (ops); |
c7c14b96 | 200 | generic_mourn_inferior (); |
5bf970f9 AC |
201 | } |
202 | ||
4b8a1a28 MK |
203 | /* Attach to the process specified by ARGS. If FROM_TTY is non-zero, |
204 | be chatty about it. */ | |
5bf970f9 AC |
205 | |
206 | static void | |
136d6dae | 207 | inf_ptrace_attach (struct target_ops *ops, char *args, int from_tty) |
5bf970f9 AC |
208 | { |
209 | char *exec_file; | |
4b8a1a28 | 210 | pid_t pid; |
5bf970f9 | 211 | char *dummy; |
181e7f93 | 212 | struct inferior *inf; |
5bf970f9 AC |
213 | |
214 | if (!args) | |
e2e0b3e5 | 215 | error_no_arg (_("process-id to attach")); |
5bf970f9 AC |
216 | |
217 | dummy = args; | |
218 | pid = strtol (args, &dummy, 0); | |
f6ffd89b | 219 | /* Some targets don't set errno on errors, grrr! */ |
6e1e94ea | 220 | if (pid == 0 && args == dummy) |
8a3fe4f8 | 221 | error (_("Illegal process-id: %s."), args); |
5bf970f9 | 222 | |
f6ffd89b | 223 | if (pid == getpid ()) /* Trying to masturbate? */ |
8a3fe4f8 | 224 | error (_("I refuse to debug myself!")); |
5bf970f9 AC |
225 | |
226 | if (from_tty) | |
227 | { | |
4b8a1a28 | 228 | exec_file = get_exec_file (0); |
5bf970f9 AC |
229 | |
230 | if (exec_file) | |
a3f17187 | 231 | printf_unfiltered (_("Attaching to program: %s, %s\n"), exec_file, |
5bf970f9 AC |
232 | target_pid_to_str (pid_to_ptid (pid))); |
233 | else | |
a3f17187 | 234 | printf_unfiltered (_("Attaching to %s\n"), |
5bf970f9 AC |
235 | target_pid_to_str (pid_to_ptid (pid))); |
236 | ||
237 | gdb_flush (gdb_stdout); | |
238 | } | |
239 | ||
6e1e94ea MK |
240 | #ifdef PT_ATTACH |
241 | errno = 0; | |
4b8a1a28 | 242 | ptrace (PT_ATTACH, pid, (PTRACE_TYPE_ARG3)0, 0); |
6e1e94ea | 243 | if (errno != 0) |
e2e0b3e5 | 244 | perror_with_name (("ptrace")); |
6e1e94ea | 245 | #else |
8a3fe4f8 | 246 | error (_("This system does not support attaching to a process")); |
6e1e94ea | 247 | #endif |
5bf970f9 AC |
248 | |
249 | inferior_ptid = pid_to_ptid (pid); | |
af990527 | 250 | |
181e7f93 PA |
251 | inf = add_inferior (pid); |
252 | inf->attach_flag = 1; | |
7f9f62ba | 253 | |
af990527 PA |
254 | /* Always add a main thread. If some target extends the ptrace |
255 | target, it should decorate the ptid later with more info. */ | |
256 | add_thread_silent (inferior_ptid); | |
257 | ||
136d6dae | 258 | push_target(ops); |
5bf970f9 AC |
259 | } |
260 | ||
e4ef629d MK |
261 | #ifdef PT_GET_PROCESS_STATE |
262 | ||
263 | void | |
264 | inf_ptrace_post_attach (int pid) | |
265 | { | |
266 | ptrace_event_t pe; | |
267 | ||
268 | /* Set the initial event mask. */ | |
269 | memset (&pe, 0, sizeof pe); | |
270 | pe.pe_set_event |= PTRACE_FORK; | |
271 | if (ptrace (PT_SET_EVENT_MASK, pid, | |
272 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) | |
273 | perror_with_name (("ptrace")); | |
274 | } | |
275 | ||
276 | #endif | |
277 | ||
4b8a1a28 | 278 | /* Detach from the inferior, optionally passing it the signal |
f010475d | 279 | specified by ARGS. If FROM_TTY is non-zero, be chatty about it. */ |
5bf970f9 AC |
280 | |
281 | static void | |
136d6dae | 282 | inf_ptrace_detach (struct target_ops *ops, char *args, int from_tty) |
5bf970f9 | 283 | { |
4b8a1a28 | 284 | pid_t pid = ptid_get_pid (inferior_ptid); |
6e1e94ea | 285 | int sig = 0; |
5bf970f9 AC |
286 | |
287 | if (from_tty) | |
288 | { | |
289 | char *exec_file = get_exec_file (0); | |
290 | if (exec_file == 0) | |
291 | exec_file = ""; | |
a3f17187 | 292 | printf_unfiltered (_("Detaching from program: %s, %s\n"), exec_file, |
5bf970f9 AC |
293 | target_pid_to_str (pid_to_ptid (pid))); |
294 | gdb_flush (gdb_stdout); | |
295 | } | |
296 | if (args) | |
6e1e94ea | 297 | sig = atoi (args); |
5bf970f9 | 298 | |
6e1e94ea | 299 | #ifdef PT_DETACH |
4b8a1a28 | 300 | /* We'd better not have left any breakpoints in the program or it'll |
f010475d | 301 | die when it hits one. Also note that this may only work if we |
4b8a1a28 MK |
302 | previously attached to the inferior. It *might* work if we |
303 | started the process ourselves. */ | |
6e1e94ea | 304 | errno = 0; |
4b8a1a28 | 305 | ptrace (PT_DETACH, pid, (PTRACE_TYPE_ARG3)1, sig); |
6e1e94ea | 306 | if (errno != 0) |
e2e0b3e5 | 307 | perror_with_name (("ptrace")); |
6e1e94ea | 308 | #else |
8a3fe4f8 | 309 | error (_("This system does not support detaching from a process")); |
6e1e94ea | 310 | #endif |
5bf970f9 AC |
311 | |
312 | inferior_ptid = null_ptid; | |
7f9f62ba | 313 | detach_inferior (pid); |
7a7d3353 PA |
314 | |
315 | if (!have_inferiors ()) | |
316 | unpush_target (ops); | |
5bf970f9 AC |
317 | } |
318 | ||
4b8a1a28 MK |
319 | /* Kill the inferior. */ |
320 | ||
5bf970f9 | 321 | static void |
4b8a1a28 | 322 | inf_ptrace_kill (void) |
5bf970f9 | 323 | { |
4b8a1a28 | 324 | pid_t pid = ptid_get_pid (inferior_ptid); |
c7c14b96 | 325 | int status; |
c7c14b96 MK |
326 | |
327 | if (pid == 0) | |
328 | return; | |
329 | ||
4b8a1a28 MK |
330 | ptrace (PT_KILL, pid, (PTRACE_TYPE_ARG3)0, 0); |
331 | waitpid (pid, &status, 0); | |
332 | ||
c7c14b96 | 333 | target_mourn_inferior (); |
5bf970f9 AC |
334 | } |
335 | ||
4b8a1a28 | 336 | /* Stop the inferior. */ |
c7c14b96 | 337 | |
5bf970f9 | 338 | static void |
94cc34af | 339 | inf_ptrace_stop (ptid_t ptid) |
5bf970f9 | 340 | { |
4b8a1a28 MK |
341 | /* Send a SIGINT to the process group. This acts just like the user |
342 | typed a ^C on the controlling terminal. Note that using a | |
343 | negative process number in kill() is a System V-ism. The proper | |
344 | BSD interface is killpg(). However, all modern BSDs support the | |
345 | System V interface too. */ | |
c7c14b96 | 346 | kill (-inferior_process_group, SIGINT); |
5bf970f9 AC |
347 | } |
348 | ||
4b8a1a28 MK |
349 | /* Resume execution of thread PTID, or all threads if PTID is -1. If |
350 | STEP is nonzero, single-step it. If SIGNAL is nonzero, give it | |
351 | that signal. */ | |
5bf970f9 AC |
352 | |
353 | static void | |
c7c14b96 | 354 | inf_ptrace_resume (ptid_t ptid, int step, enum target_signal signal) |
5bf970f9 | 355 | { |
4b8a1a28 | 356 | pid_t pid = ptid_get_pid (ptid); |
c7c14b96 | 357 | int request = PT_CONTINUE; |
c7c14b96 MK |
358 | |
359 | if (pid == -1) | |
4b8a1a28 MK |
360 | /* Resume all threads. Traditionally ptrace() only supports |
361 | single-threaded processes, so simply resume the inferior. */ | |
362 | pid = ptid_get_pid (inferior_ptid); | |
c7c14b96 MK |
363 | |
364 | if (step) | |
365 | { | |
366 | /* If this system does not support PT_STEP, a higher level | |
367 | function will have called single_step() to transmute the step | |
368 | request into a continue request (by setting breakpoints on | |
369 | all possible successor instructions), so we don't have to | |
370 | worry about that here. */ | |
371 | request = PT_STEP; | |
372 | } | |
373 | ||
374 | /* An address of (PTRACE_TYPE_ARG3)1 tells ptrace to continue from | |
375 | where it was. If GDB wanted it to start some other way, we have | |
4b8a1a28 | 376 | already written a new program counter value to the child. */ |
c7c14b96 | 377 | errno = 0; |
4b8a1a28 | 378 | ptrace (request, pid, (PTRACE_TYPE_ARG3)1, target_signal_to_host (signal)); |
c7c14b96 MK |
379 | if (errno != 0) |
380 | perror_with_name (("ptrace")); | |
5bf970f9 AC |
381 | } |
382 | ||
4b8a1a28 MK |
383 | /* Wait for the child specified by PTID to do something. Return the |
384 | process ID of the child, or MINUS_ONE_PTID in case of error; store | |
385 | the status in *OURSTATUS. */ | |
5bf970f9 | 386 | |
c7c14b96 | 387 | static ptid_t |
117de6a9 PA |
388 | inf_ptrace_wait (struct target_ops *ops, |
389 | ptid_t ptid, struct target_waitstatus *ourstatus) | |
5bf970f9 | 390 | { |
4b8a1a28 MK |
391 | pid_t pid; |
392 | int status, save_errno; | |
5bf970f9 | 393 | |
c7c14b96 MK |
394 | do |
395 | { | |
4b8a1a28 | 396 | set_sigint_trap (); |
5bf970f9 | 397 | |
4b8a1a28 MK |
398 | do |
399 | { | |
400 | pid = waitpid (ptid_get_pid (ptid), &status, 0); | |
401 | save_errno = errno; | |
402 | } | |
403 | while (pid == -1 && errno == EINTR); | |
5bf970f9 | 404 | |
c7c14b96 | 405 | clear_sigint_trap (); |
5bf970f9 | 406 | |
c7c14b96 MK |
407 | if (pid == -1) |
408 | { | |
c7c14b96 | 409 | fprintf_unfiltered (gdb_stderr, |
4b8a1a28 | 410 | _("Child process unexpectedly missing: %s.\n"), |
c7c14b96 MK |
411 | safe_strerror (save_errno)); |
412 | ||
413 | /* Claim it exited with unknown signal. */ | |
414 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; | |
415 | ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN; | |
fb66883a | 416 | return inferior_ptid; |
c7c14b96 MK |
417 | } |
418 | ||
4b8a1a28 MK |
419 | /* Ignore terminated detached child processes. */ |
420 | if (!WIFSTOPPED (status) && pid != ptid_get_pid (inferior_ptid)) | |
421 | pid = -1; | |
c7c14b96 | 422 | } |
4b8a1a28 | 423 | while (pid == -1); |
c7c14b96 | 424 | |
735f54b4 MK |
425 | #ifdef PT_GET_PROCESS_STATE |
426 | if (WIFSTOPPED (status)) | |
427 | { | |
428 | ptrace_state_t pe; | |
429 | pid_t fpid; | |
430 | ||
431 | if (ptrace (PT_GET_PROCESS_STATE, pid, | |
432 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) | |
433 | perror_with_name (("ptrace")); | |
434 | ||
435 | switch (pe.pe_report_event) | |
436 | { | |
437 | case PTRACE_FORK: | |
438 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
3a3e9ee3 | 439 | ourstatus->value.related_pid = pid_to_ptid (pe.pe_other_pid); |
735f54b4 MK |
440 | |
441 | /* Make sure the other end of the fork is stopped too. */ | |
442 | fpid = waitpid (pe.pe_other_pid, &status, 0); | |
443 | if (fpid == -1) | |
444 | perror_with_name (("waitpid")); | |
445 | ||
446 | if (ptrace (PT_GET_PROCESS_STATE, fpid, | |
447 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) | |
448 | perror_with_name (("ptrace")); | |
449 | ||
450 | gdb_assert (pe.pe_report_event == PTRACE_FORK); | |
451 | gdb_assert (pe.pe_other_pid == pid); | |
452 | if (fpid == ptid_get_pid (inferior_ptid)) | |
453 | { | |
3a3e9ee3 | 454 | ourstatus->value.related_pid = pid_to_ptid (pe.pe_other_pid); |
735f54b4 MK |
455 | return pid_to_ptid (fpid); |
456 | } | |
457 | ||
458 | return pid_to_ptid (pid); | |
459 | } | |
460 | } | |
461 | #endif | |
462 | ||
c7c14b96 MK |
463 | store_waitstatus (ourstatus, status); |
464 | return pid_to_ptid (pid); | |
5bf970f9 AC |
465 | } |
466 | ||
4b8a1a28 MK |
467 | /* Attempt a transfer all LEN bytes starting at OFFSET between the |
468 | inferior's OBJECT:ANNEX space and GDB's READBUF/WRITEBUF buffer. | |
469 | Return the number of bytes actually transferred. */ | |
5bf970f9 AC |
470 | |
471 | static LONGEST | |
472 | inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object, | |
961cb7b5 MK |
473 | const char *annex, gdb_byte *readbuf, |
474 | const gdb_byte *writebuf, | |
475 | ULONGEST offset, LONGEST len) | |
5bf970f9 | 476 | { |
4b8a1a28 MK |
477 | pid_t pid = ptid_get_pid (inferior_ptid); |
478 | ||
5bf970f9 AC |
479 | switch (object) |
480 | { | |
481 | case TARGET_OBJECT_MEMORY: | |
f929a579 AC |
482 | #ifdef PT_IO |
483 | /* OpenBSD 3.1, NetBSD 1.6 and FreeBSD 5.0 have a new PT_IO | |
484 | request that promises to be much more efficient in reading | |
485 | and writing data in the traced process's address space. */ | |
486 | { | |
487 | struct ptrace_io_desc piod; | |
4b8a1a28 | 488 | |
f929a579 | 489 | /* NOTE: We assume that there are no distinct address spaces |
b457b3dd MK |
490 | for instruction and data. However, on OpenBSD 3.9 and |
491 | later, PIOD_WRITE_D doesn't allow changing memory that's | |
492 | mapped read-only. Since most code segments will be | |
493 | read-only, using PIOD_WRITE_D will prevent us from | |
494 | inserting breakpoints, so we use PIOD_WRITE_I instead. */ | |
495 | piod.piod_op = writebuf ? PIOD_WRITE_I : PIOD_READ_D; | |
f929a579 AC |
496 | piod.piod_addr = writebuf ? (void *) writebuf : readbuf; |
497 | piod.piod_offs = (void *) (long) offset; | |
498 | piod.piod_len = len; | |
499 | ||
500 | errno = 0; | |
4b8a1a28 | 501 | if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0) |
f929a579 AC |
502 | /* Return the actual number of bytes read or written. */ |
503 | return piod.piod_len; | |
504 | /* If the PT_IO request is somehow not supported, fallback on | |
505 | using PT_WRITE_D/PT_READ_D. Otherwise we will return zero | |
506 | to indicate failure. */ | |
507 | if (errno != EINVAL) | |
508 | return 0; | |
509 | } | |
510 | #endif | |
511 | { | |
512 | union | |
513 | { | |
514 | PTRACE_TYPE_RET word; | |
4b8a1a28 | 515 | gdb_byte byte[sizeof (PTRACE_TYPE_RET)]; |
f929a579 AC |
516 | } buffer; |
517 | ULONGEST rounded_offset; | |
518 | LONGEST partial_len; | |
4b8a1a28 | 519 | |
cb85a953 AC |
520 | /* Round the start offset down to the next long word |
521 | boundary. */ | |
f929a579 | 522 | rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET); |
4b8a1a28 | 523 | |
cb85a953 AC |
524 | /* Since ptrace will transfer a single word starting at that |
525 | rounded_offset the partial_len needs to be adjusted down to | |
526 | that (remember this function only does a single transfer). | |
527 | Should the required length be even less, adjust it down | |
528 | again. */ | |
529 | partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset; | |
530 | if (partial_len > len) | |
f929a579 | 531 | partial_len = len; |
4b8a1a28 | 532 | |
f929a579 AC |
533 | if (writebuf) |
534 | { | |
cb85a953 AC |
535 | /* If OFFSET:PARTIAL_LEN is smaller than |
536 | ROUNDED_OFFSET:WORDSIZE then a read/modify write will | |
537 | be needed. Read in the entire word. */ | |
f929a579 | 538 | if (rounded_offset < offset |
cb85a953 AC |
539 | || (offset + partial_len |
540 | < rounded_offset + sizeof (PTRACE_TYPE_RET))) | |
f929a579 | 541 | /* Need part of initial word -- fetch it. */ |
4b8a1a28 | 542 | buffer.word = ptrace (PT_READ_I, pid, |
f7dd0ed7 UW |
543 | (PTRACE_TYPE_ARG3)(uintptr_t) |
544 | rounded_offset, 0); | |
4b8a1a28 | 545 | |
f929a579 AC |
546 | /* Copy data to be written over corresponding part of |
547 | buffer. */ | |
f6ffd89b MK |
548 | memcpy (buffer.byte + (offset - rounded_offset), |
549 | writebuf, partial_len); | |
4b8a1a28 | 550 | |
f929a579 | 551 | errno = 0; |
4b8a1a28 | 552 | ptrace (PT_WRITE_D, pid, |
f7dd0ed7 UW |
553 | (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset, |
554 | buffer.word); | |
f929a579 AC |
555 | if (errno) |
556 | { | |
557 | /* Using the appropriate one (I or D) is necessary for | |
558 | Gould NP1, at least. */ | |
559 | errno = 0; | |
4b8a1a28 | 560 | ptrace (PT_WRITE_I, pid, |
f7dd0ed7 UW |
561 | (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset, |
562 | buffer.word); | |
f929a579 AC |
563 | if (errno) |
564 | return 0; | |
565 | } | |
566 | } | |
4b8a1a28 | 567 | |
f929a579 AC |
568 | if (readbuf) |
569 | { | |
570 | errno = 0; | |
4b8a1a28 | 571 | buffer.word = ptrace (PT_READ_I, pid, |
f7dd0ed7 UW |
572 | (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset, |
573 | 0); | |
f929a579 AC |
574 | if (errno) |
575 | return 0; | |
576 | /* Copy appropriate bytes out of the buffer. */ | |
577 | memcpy (readbuf, buffer.byte + (offset - rounded_offset), | |
578 | partial_len); | |
579 | } | |
4b8a1a28 | 580 | |
f929a579 AC |
581 | return partial_len; |
582 | } | |
5bf970f9 AC |
583 | |
584 | case TARGET_OBJECT_UNWIND_TABLE: | |
585 | return -1; | |
586 | ||
587 | case TARGET_OBJECT_AUXV: | |
588 | return -1; | |
589 | ||
590 | case TARGET_OBJECT_WCOOKIE: | |
591 | return -1; | |
592 | ||
593 | default: | |
594 | return -1; | |
595 | } | |
596 | } | |
597 | ||
4b8a1a28 | 598 | /* Return non-zero if the thread specified by PTID is alive. */ |
c7c14b96 MK |
599 | |
600 | static int | |
601 | inf_ptrace_thread_alive (ptid_t ptid) | |
602 | { | |
4b8a1a28 MK |
603 | /* ??? Is kill the right way to do this? */ |
604 | return (kill (ptid_get_pid (ptid), 0) != -1); | |
c7c14b96 MK |
605 | } |
606 | ||
607 | /* Print status information about what we're accessing. */ | |
608 | ||
609 | static void | |
610 | inf_ptrace_files_info (struct target_ops *ignore) | |
611 | { | |
181e7f93 PA |
612 | struct inferior *inf = current_inferior (); |
613 | ||
4b8a1a28 | 614 | printf_filtered (_("\tUsing the running image of %s %s.\n"), |
181e7f93 | 615 | inf->attach_flag ? "attached" : "child", |
4b8a1a28 | 616 | target_pid_to_str (inferior_ptid)); |
5bf970f9 AC |
617 | } |
618 | ||
117de6a9 PA |
619 | static char * |
620 | inf_ptrace_pid_to_str (struct target_ops *ops, ptid_t ptid) | |
621 | { | |
622 | return normal_pid_to_str (ptid); | |
623 | } | |
624 | ||
8785ced0 MK |
625 | /* Create a prototype ptrace target. The client can override it with |
626 | local methods. */ | |
627 | ||
5bf970f9 AC |
628 | struct target_ops * |
629 | inf_ptrace_target (void) | |
630 | { | |
631 | struct target_ops *t = inf_child_target (); | |
8785ced0 | 632 | |
5bf970f9 | 633 | t->to_attach = inf_ptrace_attach; |
5bf970f9 AC |
634 | t->to_detach = inf_ptrace_detach; |
635 | t->to_resume = inf_ptrace_resume; | |
636 | t->to_wait = inf_ptrace_wait; | |
5bf970f9 | 637 | t->to_files_info = inf_ptrace_files_info; |
4b8a1a28 | 638 | t->to_kill = inf_ptrace_kill; |
5bf970f9 | 639 | t->to_create_inferior = inf_ptrace_create_inferior; |
735f54b4 MK |
640 | #ifdef PT_GET_PROCESS_STATE |
641 | t->to_follow_fork = inf_ptrace_follow_fork; | |
e4ef629d MK |
642 | t->to_post_startup_inferior = inf_ptrace_post_startup_inferior; |
643 | t->to_post_attach = inf_ptrace_post_attach; | |
735f54b4 | 644 | #endif |
5bf970f9 | 645 | t->to_mourn_inferior = inf_ptrace_mourn_inferior; |
5bf970f9 | 646 | t->to_thread_alive = inf_ptrace_thread_alive; |
117de6a9 | 647 | t->to_pid_to_str = inf_ptrace_pid_to_str; |
5bf970f9 | 648 | t->to_stop = inf_ptrace_stop; |
c7c14b96 | 649 | t->to_xfer_partial = inf_ptrace_xfer_partial; |
8785ced0 MK |
650 | |
651 | return t; | |
652 | } | |
653 | \f | |
654 | ||
4b8a1a28 | 655 | /* Pointer to a function that returns the offset within the user area |
8785ced0 | 656 | where a particular register is stored. */ |
7714d83a | 657 | static CORE_ADDR (*inf_ptrace_register_u_offset)(struct gdbarch *, int, int); |
8785ced0 MK |
658 | |
659 | /* Fetch register REGNUM from the inferior. */ | |
660 | ||
661 | static void | |
56be3814 | 662 | inf_ptrace_fetch_register (struct regcache *regcache, int regnum) |
8785ced0 | 663 | { |
3b3b1423 | 664 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
8785ced0 MK |
665 | CORE_ADDR addr; |
666 | size_t size; | |
667 | PTRACE_TYPE_RET *buf; | |
668 | int pid, i; | |
669 | ||
7714d83a | 670 | /* This isn't really an address, but ptrace thinks of it as one. */ |
3b3b1423 | 671 | addr = inf_ptrace_register_u_offset (gdbarch, regnum, 0); |
8d4c1ba3 | 672 | if (addr == (CORE_ADDR)-1 |
3b3b1423 | 673 | || gdbarch_cannot_fetch_register (gdbarch, regnum)) |
10d6c8cd | 674 | { |
56be3814 | 675 | regcache_raw_supply (regcache, regnum, NULL); |
10d6c8cd DJ |
676 | return; |
677 | } | |
678 | ||
8785ced0 | 679 | /* Cater for systems like GNU/Linux, that implement threads as |
10d6c8cd | 680 | separate processes. */ |
8785ced0 MK |
681 | pid = ptid_get_lwp (inferior_ptid); |
682 | if (pid == 0) | |
683 | pid = ptid_get_pid (inferior_ptid); | |
684 | ||
3b3b1423 | 685 | size = register_size (gdbarch, regnum); |
8785ced0 MK |
686 | gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0); |
687 | buf = alloca (size); | |
688 | ||
10d6c8cd | 689 | /* Read the register contents from the inferior a chunk at a time. */ |
8785ced0 MK |
690 | for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++) |
691 | { | |
692 | errno = 0; | |
f7dd0ed7 | 693 | buf[i] = ptrace (PT_READ_U, pid, (PTRACE_TYPE_ARG3)(uintptr_t)addr, 0); |
8785ced0 | 694 | if (errno != 0) |
4b8a1a28 | 695 | error (_("Couldn't read register %s (#%d): %s."), |
3b3b1423 | 696 | gdbarch_register_name (gdbarch, regnum), |
c9f4d572 | 697 | regnum, safe_strerror (errno)); |
8785ced0 MK |
698 | |
699 | addr += sizeof (PTRACE_TYPE_RET); | |
700 | } | |
56be3814 | 701 | regcache_raw_supply (regcache, regnum, buf); |
8785ced0 MK |
702 | } |
703 | ||
704 | /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this | |
705 | for all registers. */ | |
706 | ||
707 | static void | |
56be3814 | 708 | inf_ptrace_fetch_registers (struct regcache *regcache, int regnum) |
8785ced0 MK |
709 | { |
710 | if (regnum == -1) | |
3b3b1423 UW |
711 | for (regnum = 0; |
712 | regnum < gdbarch_num_regs (get_regcache_arch (regcache)); | |
713 | regnum++) | |
56be3814 | 714 | inf_ptrace_fetch_register (regcache, regnum); |
8785ced0 | 715 | else |
56be3814 | 716 | inf_ptrace_fetch_register (regcache, regnum); |
8785ced0 MK |
717 | } |
718 | ||
719 | /* Store register REGNUM into the inferior. */ | |
720 | ||
721 | static void | |
56be3814 | 722 | inf_ptrace_store_register (const struct regcache *regcache, int regnum) |
8785ced0 | 723 | { |
3b3b1423 | 724 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
8785ced0 MK |
725 | CORE_ADDR addr; |
726 | size_t size; | |
727 | PTRACE_TYPE_RET *buf; | |
728 | int pid, i; | |
729 | ||
7714d83a | 730 | /* This isn't really an address, but ptrace thinks of it as one. */ |
3b3b1423 | 731 | addr = inf_ptrace_register_u_offset (gdbarch, regnum, 1); |
8d4c1ba3 | 732 | if (addr == (CORE_ADDR)-1 |
3b3b1423 | 733 | || gdbarch_cannot_store_register (gdbarch, regnum)) |
10d6c8cd DJ |
734 | return; |
735 | ||
8785ced0 | 736 | /* Cater for systems like GNU/Linux, that implement threads as |
10d6c8cd | 737 | separate processes. */ |
8785ced0 MK |
738 | pid = ptid_get_lwp (inferior_ptid); |
739 | if (pid == 0) | |
740 | pid = ptid_get_pid (inferior_ptid); | |
741 | ||
3b3b1423 | 742 | size = register_size (gdbarch, regnum); |
8785ced0 MK |
743 | gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0); |
744 | buf = alloca (size); | |
745 | ||
10d6c8cd | 746 | /* Write the register contents into the inferior a chunk at a time. */ |
56be3814 | 747 | regcache_raw_collect (regcache, regnum, buf); |
8785ced0 MK |
748 | for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++) |
749 | { | |
750 | errno = 0; | |
f7dd0ed7 | 751 | ptrace (PT_WRITE_U, pid, (PTRACE_TYPE_ARG3)(uintptr_t)addr, buf[i]); |
8785ced0 | 752 | if (errno != 0) |
4b8a1a28 | 753 | error (_("Couldn't write register %s (#%d): %s."), |
3b3b1423 | 754 | gdbarch_register_name (gdbarch, regnum), |
c9f4d572 | 755 | regnum, safe_strerror (errno)); |
8785ced0 MK |
756 | |
757 | addr += sizeof (PTRACE_TYPE_RET); | |
758 | } | |
759 | } | |
760 | ||
761 | /* Store register REGNUM back into the inferior. If REGNUM is -1, do | |
762 | this for all registers. */ | |
763 | ||
764 | void | |
56be3814 | 765 | inf_ptrace_store_registers (struct regcache *regcache, int regnum) |
8785ced0 MK |
766 | { |
767 | if (regnum == -1) | |
3b3b1423 UW |
768 | for (regnum = 0; |
769 | regnum < gdbarch_num_regs (get_regcache_arch (regcache)); | |
770 | regnum++) | |
56be3814 | 771 | inf_ptrace_store_register (regcache, regnum); |
8785ced0 | 772 | else |
56be3814 | 773 | inf_ptrace_store_register (regcache, regnum); |
8785ced0 MK |
774 | } |
775 | ||
776 | /* Create a "traditional" ptrace target. REGISTER_U_OFFSET should be | |
777 | a function returning the offset within the user area where a | |
778 | particular register is stored. */ | |
779 | ||
780 | struct target_ops * | |
7714d83a UW |
781 | inf_ptrace_trad_target (CORE_ADDR (*register_u_offset) |
782 | (struct gdbarch *, int, int)) | |
8785ced0 MK |
783 | { |
784 | struct target_ops *t = inf_ptrace_target(); | |
785 | ||
786 | gdb_assert (register_u_offset); | |
787 | inf_ptrace_register_u_offset = register_u_offset; | |
788 | t->to_fetch_registers = inf_ptrace_fetch_registers; | |
789 | t->to_store_registers = inf_ptrace_store_registers; | |
790 | ||
5bf970f9 AC |
791 | return t; |
792 | } |