Commit | Line | Data |
---|---|---|
2c4a536d | 1 | /* Low-level child interface to ptrace. |
5bf970f9 AC |
2 | |
3 | Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, | |
8785ced0 MK |
4 | 1998, 1999, 2000, 2001, 2002, 2004, 2005 |
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 | |
11 | the Free Software Foundation; either version 2 of the License, or | |
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 | |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | Boston, MA 02111-1307, USA. */ | |
23 | ||
24 | #include "defs.h" | |
5bf970f9 | 25 | #include "command.h" |
2c4a536d MK |
26 | #include "inferior.h" |
27 | #include "inflow.h" | |
5bf970f9 | 28 | #include "gdbcore.h" |
2c4a536d | 29 | #include "observer.h" |
8785ced0 | 30 | #include "regcache.h" |
5bf970f9 | 31 | |
8785ced0 | 32 | #include "gdb_assert.h" |
2c4a536d MK |
33 | #include "gdb_string.h" |
34 | #include "gdb_ptrace.h" | |
34a17005 | 35 | #include "gdb_wait.h" |
5bf970f9 AC |
36 | #include <signal.h> |
37 | ||
2c4a536d MK |
38 | #include "inf-child.h" |
39 | ||
40 | /* HACK: Save the ptrace ops returned by inf_ptrace_target. */ | |
5bf970f9 | 41 | static struct target_ops *ptrace_ops_hack; |
c7c14b96 MK |
42 | \f |
43 | ||
735f54b4 MK |
44 | #ifdef PT_GET_PROCESS_STATE |
45 | ||
46 | static int | |
ee057212 | 47 | inf_ptrace_follow_fork (struct target_ops *ops, int follow_child) |
735f54b4 MK |
48 | { |
49 | pid_t pid, fpid; | |
50 | ptrace_state_t pe; | |
51 | ||
52 | /* FIXME: kettenis/20050720: This stuff should really be passed as | |
53 | an argument by our caller. */ | |
54 | { | |
55 | ptid_t ptid; | |
56 | struct target_waitstatus status; | |
57 | ||
58 | get_last_target_status (&ptid, &status); | |
59 | gdb_assert (status.kind == TARGET_WAITKIND_FORKED); | |
60 | ||
61 | pid = ptid_get_pid (ptid); | |
62 | } | |
63 | ||
64 | if (ptrace (PT_GET_PROCESS_STATE, pid, | |
65 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) | |
66 | perror_with_name (("ptrace")); | |
67 | ||
68 | gdb_assert (pe.pe_report_event == PTRACE_FORK); | |
69 | fpid = pe.pe_other_pid; | |
70 | ||
71 | if (follow_child) | |
72 | { | |
73 | inferior_ptid = pid_to_ptid (fpid); | |
74 | detach_breakpoints (pid); | |
75 | ||
76 | /* Reset breakpoints in the child as appropriate. */ | |
77 | follow_inferior_reset_breakpoints (); | |
78 | ||
79 | if (ptrace (PT_DETACH, pid, (PTRACE_TYPE_ARG3)1, 0) == -1) | |
80 | perror_with_name (("ptrace")); | |
81 | } | |
82 | else | |
83 | { | |
84 | inferior_ptid = pid_to_ptid (pid); | |
85 | detach_breakpoints (fpid); | |
86 | ||
87 | if (ptrace (PT_DETACH, fpid, (PTRACE_TYPE_ARG3)1, 0) == -1) | |
88 | perror_with_name (("ptrace")); | |
89 | } | |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
94 | #endif /* PT_GET_PROCESS_STATE */ | |
95 | \f | |
96 | ||
4b8a1a28 | 97 | /* Prepare to be traced. */ |
5bf970f9 AC |
98 | |
99 | static void | |
c7c14b96 | 100 | inf_ptrace_me (void) |
5bf970f9 | 101 | { |
c7c14b96 | 102 | /* "Trace me, Dr. Memory!" */ |
4b8a1a28 | 103 | ptrace (PT_TRACE_ME, 0, (PTRACE_TYPE_ARG3)0, 0); |
5bf970f9 AC |
104 | } |
105 | ||
4b8a1a28 | 106 | /* Start tracing PID. */ |
5bf970f9 AC |
107 | |
108 | static void | |
c7c14b96 | 109 | inf_ptrace_him (int pid) |
5bf970f9 | 110 | { |
c7c14b96 | 111 | push_target (ptrace_ops_hack); |
5bf970f9 | 112 | |
c7c14b96 MK |
113 | /* On some targets, there must be some explicit synchronization |
114 | between the parent and child processes after the debugger | |
115 | forks, and before the child execs the debuggee program. This | |
116 | call basically gives permission for the child to exec. */ | |
5bf970f9 | 117 | |
c7c14b96 | 118 | target_acknowledge_created_inferior (pid); |
5bf970f9 | 119 | |
c7c14b96 MK |
120 | /* START_INFERIOR_TRAPS_EXPECTED is defined in inferior.h, and will |
121 | be 1 or 2 depending on whether we're starting without or with a | |
122 | shell. */ | |
123 | startup_inferior (START_INFERIOR_TRAPS_EXPECTED); | |
124 | ||
125 | /* On some targets, there must be some explicit actions taken after | |
126 | the inferior has been started up. */ | |
127 | target_post_startup_inferior (pid_to_ptid (pid)); | |
5bf970f9 AC |
128 | } |
129 | ||
4b8a1a28 MK |
130 | /* Start a new inferior Unix child process. EXEC_FILE is the file to |
131 | run, ALLARGS is a string containing the arguments to the program. | |
132 | ENV is the environment vector to pass. If FROM_TTY is non-zero, be | |
133 | chatty about it. */ | |
5bf970f9 | 134 | |
c7c14b96 MK |
135 | static void |
136 | inf_ptrace_create_inferior (char *exec_file, char *allargs, char **env, | |
137 | int from_tty) | |
5bf970f9 | 138 | { |
c7c14b96 MK |
139 | fork_inferior (exec_file, allargs, env, inf_ptrace_me, inf_ptrace_him, |
140 | NULL, NULL); | |
4b8a1a28 | 141 | |
c7c14b96 MK |
142 | /* We are at the first instruction we care about. */ |
143 | observer_notify_inferior_created (¤t_target, from_tty); | |
4b8a1a28 | 144 | |
c7c14b96 MK |
145 | /* Pedal to the metal... */ |
146 | proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0); | |
5bf970f9 AC |
147 | } |
148 | ||
e4ef629d MK |
149 | #ifdef PT_GET_PROCESS_STATE |
150 | ||
151 | static void | |
152 | inf_ptrace_post_startup_inferior (ptid_t pid) | |
153 | { | |
154 | ptrace_event_t pe; | |
155 | ||
156 | /* Set the initial event mask. */ | |
157 | memset (&pe, 0, sizeof pe); | |
158 | pe.pe_set_event |= PTRACE_FORK; | |
159 | if (ptrace (PT_SET_EVENT_MASK, ptid_get_pid (pid), | |
160 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) | |
161 | perror_with_name (("ptrace")); | |
162 | } | |
163 | ||
164 | #endif | |
165 | ||
4b8a1a28 MK |
166 | /* Clean up a rotting corpse of an inferior after it died. */ |
167 | ||
c7c14b96 MK |
168 | static void |
169 | inf_ptrace_mourn_inferior (void) | |
5bf970f9 | 170 | { |
4b8a1a28 MK |
171 | int status; |
172 | ||
173 | /* Wait just one more time to collect the inferior's exit status. | |
174 | Don not check whether this succeeds though, since we may be | |
175 | dealing with a process that we attached to. Such a process will | |
176 | only report its exit status to its origional parent. */ | |
177 | waitpid (ptid_get_pid (inferior_ptid), &status, 0); | |
178 | ||
c7c14b96 MK |
179 | unpush_target (ptrace_ops_hack); |
180 | generic_mourn_inferior (); | |
5bf970f9 AC |
181 | } |
182 | ||
4b8a1a28 MK |
183 | /* Attach to the process specified by ARGS. If FROM_TTY is non-zero, |
184 | be chatty about it. */ | |
5bf970f9 AC |
185 | |
186 | static void | |
187 | inf_ptrace_attach (char *args, int from_tty) | |
188 | { | |
189 | char *exec_file; | |
4b8a1a28 | 190 | pid_t pid; |
5bf970f9 AC |
191 | char *dummy; |
192 | ||
193 | if (!args) | |
e2e0b3e5 | 194 | error_no_arg (_("process-id to attach")); |
5bf970f9 AC |
195 | |
196 | dummy = args; | |
197 | pid = strtol (args, &dummy, 0); | |
f6ffd89b | 198 | /* Some targets don't set errno on errors, grrr! */ |
6e1e94ea | 199 | if (pid == 0 && args == dummy) |
8a3fe4f8 | 200 | error (_("Illegal process-id: %s."), args); |
5bf970f9 | 201 | |
f6ffd89b | 202 | if (pid == getpid ()) /* Trying to masturbate? */ |
8a3fe4f8 | 203 | error (_("I refuse to debug myself!")); |
5bf970f9 AC |
204 | |
205 | if (from_tty) | |
206 | { | |
4b8a1a28 | 207 | exec_file = get_exec_file (0); |
5bf970f9 AC |
208 | |
209 | if (exec_file) | |
a3f17187 | 210 | printf_unfiltered (_("Attaching to program: %s, %s\n"), exec_file, |
5bf970f9 AC |
211 | target_pid_to_str (pid_to_ptid (pid))); |
212 | else | |
a3f17187 | 213 | printf_unfiltered (_("Attaching to %s\n"), |
5bf970f9 AC |
214 | target_pid_to_str (pid_to_ptid (pid))); |
215 | ||
216 | gdb_flush (gdb_stdout); | |
217 | } | |
218 | ||
6e1e94ea MK |
219 | #ifdef PT_ATTACH |
220 | errno = 0; | |
4b8a1a28 | 221 | ptrace (PT_ATTACH, pid, (PTRACE_TYPE_ARG3)0, 0); |
6e1e94ea | 222 | if (errno != 0) |
e2e0b3e5 | 223 | perror_with_name (("ptrace")); |
6e1e94ea MK |
224 | attach_flag = 1; |
225 | #else | |
8a3fe4f8 | 226 | error (_("This system does not support attaching to a process")); |
6e1e94ea | 227 | #endif |
5bf970f9 AC |
228 | |
229 | inferior_ptid = pid_to_ptid (pid); | |
230 | push_target (ptrace_ops_hack); | |
12b8a2cb DJ |
231 | |
232 | /* Do this first, before anything has had a chance to query the | |
233 | inferior's symbol table or similar. */ | |
234 | observer_notify_inferior_created (¤t_target, from_tty); | |
5bf970f9 AC |
235 | } |
236 | ||
e4ef629d MK |
237 | #ifdef PT_GET_PROCESS_STATE |
238 | ||
239 | void | |
240 | inf_ptrace_post_attach (int pid) | |
241 | { | |
242 | ptrace_event_t pe; | |
243 | ||
244 | /* Set the initial event mask. */ | |
245 | memset (&pe, 0, sizeof pe); | |
246 | pe.pe_set_event |= PTRACE_FORK; | |
247 | if (ptrace (PT_SET_EVENT_MASK, pid, | |
248 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) | |
249 | perror_with_name (("ptrace")); | |
250 | } | |
251 | ||
252 | #endif | |
253 | ||
4b8a1a28 MK |
254 | /* Detach from the inferior, optionally passing it the signal |
255 | specified ARGS. If FROM_TTY is non-zero, be chatty about it. */ | |
5bf970f9 AC |
256 | |
257 | static void | |
258 | inf_ptrace_detach (char *args, int from_tty) | |
259 | { | |
4b8a1a28 | 260 | pid_t pid = ptid_get_pid (inferior_ptid); |
6e1e94ea | 261 | int sig = 0; |
5bf970f9 AC |
262 | |
263 | if (from_tty) | |
264 | { | |
265 | char *exec_file = get_exec_file (0); | |
266 | if (exec_file == 0) | |
267 | exec_file = ""; | |
a3f17187 | 268 | printf_unfiltered (_("Detaching from program: %s, %s\n"), exec_file, |
5bf970f9 AC |
269 | target_pid_to_str (pid_to_ptid (pid))); |
270 | gdb_flush (gdb_stdout); | |
271 | } | |
272 | if (args) | |
6e1e94ea | 273 | sig = atoi (args); |
5bf970f9 | 274 | |
6e1e94ea | 275 | #ifdef PT_DETACH |
4b8a1a28 MK |
276 | /* We'd better not have left any breakpoints in the program or it'll |
277 | die when it hits one. Alsno note that this may only work if we | |
278 | previously attached to the inferior. It *might* work if we | |
279 | started the process ourselves. */ | |
6e1e94ea | 280 | errno = 0; |
4b8a1a28 | 281 | ptrace (PT_DETACH, pid, (PTRACE_TYPE_ARG3)1, sig); |
6e1e94ea | 282 | if (errno != 0) |
e2e0b3e5 | 283 | perror_with_name (("ptrace")); |
6e1e94ea MK |
284 | attach_flag = 0; |
285 | #else | |
8a3fe4f8 | 286 | error (_("This system does not support detaching from a process")); |
6e1e94ea | 287 | #endif |
5bf970f9 AC |
288 | |
289 | inferior_ptid = null_ptid; | |
290 | unpush_target (ptrace_ops_hack); | |
291 | } | |
292 | ||
4b8a1a28 MK |
293 | /* Kill the inferior. */ |
294 | ||
5bf970f9 | 295 | static void |
4b8a1a28 | 296 | inf_ptrace_kill (void) |
5bf970f9 | 297 | { |
4b8a1a28 | 298 | pid_t pid = ptid_get_pid (inferior_ptid); |
c7c14b96 | 299 | int status; |
c7c14b96 MK |
300 | |
301 | if (pid == 0) | |
302 | return; | |
303 | ||
4b8a1a28 MK |
304 | ptrace (PT_KILL, pid, (PTRACE_TYPE_ARG3)0, 0); |
305 | waitpid (pid, &status, 0); | |
306 | ||
c7c14b96 | 307 | target_mourn_inferior (); |
5bf970f9 AC |
308 | } |
309 | ||
4b8a1a28 | 310 | /* Stop the inferior. */ |
c7c14b96 | 311 | |
5bf970f9 | 312 | static void |
c7c14b96 | 313 | inf_ptrace_stop (void) |
5bf970f9 | 314 | { |
4b8a1a28 MK |
315 | /* Send a SIGINT to the process group. This acts just like the user |
316 | typed a ^C on the controlling terminal. Note that using a | |
317 | negative process number in kill() is a System V-ism. The proper | |
318 | BSD interface is killpg(). However, all modern BSDs support the | |
319 | System V interface too. */ | |
c7c14b96 | 320 | kill (-inferior_process_group, SIGINT); |
5bf970f9 AC |
321 | } |
322 | ||
4b8a1a28 MK |
323 | /* Resume execution of thread PTID, or all threads if PTID is -1. If |
324 | STEP is nonzero, single-step it. If SIGNAL is nonzero, give it | |
325 | that signal. */ | |
5bf970f9 AC |
326 | |
327 | static void | |
c7c14b96 | 328 | inf_ptrace_resume (ptid_t ptid, int step, enum target_signal signal) |
5bf970f9 | 329 | { |
4b8a1a28 | 330 | pid_t pid = ptid_get_pid (ptid); |
c7c14b96 | 331 | int request = PT_CONTINUE; |
c7c14b96 MK |
332 | |
333 | if (pid == -1) | |
4b8a1a28 MK |
334 | /* Resume all threads. Traditionally ptrace() only supports |
335 | single-threaded processes, so simply resume the inferior. */ | |
336 | pid = ptid_get_pid (inferior_ptid); | |
c7c14b96 MK |
337 | |
338 | if (step) | |
339 | { | |
340 | /* If this system does not support PT_STEP, a higher level | |
341 | function will have called single_step() to transmute the step | |
342 | request into a continue request (by setting breakpoints on | |
343 | all possible successor instructions), so we don't have to | |
344 | worry about that here. */ | |
345 | request = PT_STEP; | |
346 | } | |
347 | ||
348 | /* An address of (PTRACE_TYPE_ARG3)1 tells ptrace to continue from | |
349 | where it was. If GDB wanted it to start some other way, we have | |
4b8a1a28 | 350 | already written a new program counter value to the child. */ |
c7c14b96 | 351 | errno = 0; |
4b8a1a28 | 352 | ptrace (request, pid, (PTRACE_TYPE_ARG3)1, target_signal_to_host (signal)); |
c7c14b96 MK |
353 | if (errno != 0) |
354 | perror_with_name (("ptrace")); | |
5bf970f9 AC |
355 | } |
356 | ||
4b8a1a28 MK |
357 | /* Wait for the child specified by PTID to do something. Return the |
358 | process ID of the child, or MINUS_ONE_PTID in case of error; store | |
359 | the status in *OURSTATUS. */ | |
5bf970f9 | 360 | |
c7c14b96 MK |
361 | static ptid_t |
362 | inf_ptrace_wait (ptid_t ptid, struct target_waitstatus *ourstatus) | |
5bf970f9 | 363 | { |
4b8a1a28 MK |
364 | pid_t pid; |
365 | int status, save_errno; | |
5bf970f9 | 366 | |
c7c14b96 MK |
367 | do |
368 | { | |
4b8a1a28 | 369 | set_sigint_trap (); |
c7c14b96 | 370 | set_sigio_trap (); |
5bf970f9 | 371 | |
4b8a1a28 MK |
372 | do |
373 | { | |
374 | pid = waitpid (ptid_get_pid (ptid), &status, 0); | |
375 | save_errno = errno; | |
376 | } | |
377 | while (pid == -1 && errno == EINTR); | |
5bf970f9 | 378 | |
c7c14b96 | 379 | clear_sigio_trap (); |
c7c14b96 | 380 | clear_sigint_trap (); |
5bf970f9 | 381 | |
c7c14b96 MK |
382 | if (pid == -1) |
383 | { | |
c7c14b96 | 384 | fprintf_unfiltered (gdb_stderr, |
4b8a1a28 | 385 | _("Child process unexpectedly missing: %s.\n"), |
c7c14b96 MK |
386 | safe_strerror (save_errno)); |
387 | ||
388 | /* Claim it exited with unknown signal. */ | |
389 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; | |
390 | ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN; | |
4b8a1a28 | 391 | return minus_one_ptid; |
c7c14b96 MK |
392 | } |
393 | ||
4b8a1a28 MK |
394 | /* Ignore terminated detached child processes. */ |
395 | if (!WIFSTOPPED (status) && pid != ptid_get_pid (inferior_ptid)) | |
396 | pid = -1; | |
c7c14b96 | 397 | } |
4b8a1a28 | 398 | while (pid == -1); |
c7c14b96 | 399 | |
735f54b4 MK |
400 | #ifdef PT_GET_PROCESS_STATE |
401 | if (WIFSTOPPED (status)) | |
402 | { | |
403 | ptrace_state_t pe; | |
404 | pid_t fpid; | |
405 | ||
406 | if (ptrace (PT_GET_PROCESS_STATE, pid, | |
407 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) | |
408 | perror_with_name (("ptrace")); | |
409 | ||
410 | switch (pe.pe_report_event) | |
411 | { | |
412 | case PTRACE_FORK: | |
413 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
414 | ourstatus->value.related_pid = pe.pe_other_pid; | |
415 | ||
416 | /* Make sure the other end of the fork is stopped too. */ | |
417 | fpid = waitpid (pe.pe_other_pid, &status, 0); | |
418 | if (fpid == -1) | |
419 | perror_with_name (("waitpid")); | |
420 | ||
421 | if (ptrace (PT_GET_PROCESS_STATE, fpid, | |
422 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) | |
423 | perror_with_name (("ptrace")); | |
424 | ||
425 | gdb_assert (pe.pe_report_event == PTRACE_FORK); | |
426 | gdb_assert (pe.pe_other_pid == pid); | |
427 | if (fpid == ptid_get_pid (inferior_ptid)) | |
428 | { | |
429 | ourstatus->value.related_pid = pe.pe_other_pid; | |
430 | return pid_to_ptid (fpid); | |
431 | } | |
432 | ||
433 | return pid_to_ptid (pid); | |
434 | } | |
435 | } | |
436 | #endif | |
437 | ||
c7c14b96 MK |
438 | store_waitstatus (ourstatus, status); |
439 | return pid_to_ptid (pid); | |
5bf970f9 AC |
440 | } |
441 | ||
4b8a1a28 MK |
442 | /* Attempt a transfer all LEN bytes starting at OFFSET between the |
443 | inferior's OBJECT:ANNEX space and GDB's READBUF/WRITEBUF buffer. | |
444 | Return the number of bytes actually transferred. */ | |
5bf970f9 AC |
445 | |
446 | static LONGEST | |
447 | inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object, | |
961cb7b5 MK |
448 | const char *annex, gdb_byte *readbuf, |
449 | const gdb_byte *writebuf, | |
450 | ULONGEST offset, LONGEST len) | |
5bf970f9 | 451 | { |
4b8a1a28 MK |
452 | pid_t pid = ptid_get_pid (inferior_ptid); |
453 | ||
5bf970f9 AC |
454 | switch (object) |
455 | { | |
456 | case TARGET_OBJECT_MEMORY: | |
f929a579 AC |
457 | #ifdef PT_IO |
458 | /* OpenBSD 3.1, NetBSD 1.6 and FreeBSD 5.0 have a new PT_IO | |
459 | request that promises to be much more efficient in reading | |
460 | and writing data in the traced process's address space. */ | |
461 | { | |
462 | struct ptrace_io_desc piod; | |
4b8a1a28 | 463 | |
f929a579 AC |
464 | /* NOTE: We assume that there are no distinct address spaces |
465 | for instruction and data. */ | |
466 | piod.piod_op = writebuf ? PIOD_WRITE_D : PIOD_READ_D; | |
467 | piod.piod_addr = writebuf ? (void *) writebuf : readbuf; | |
468 | piod.piod_offs = (void *) (long) offset; | |
469 | piod.piod_len = len; | |
470 | ||
471 | errno = 0; | |
4b8a1a28 | 472 | if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0) |
f929a579 AC |
473 | /* Return the actual number of bytes read or written. */ |
474 | return piod.piod_len; | |
475 | /* If the PT_IO request is somehow not supported, fallback on | |
476 | using PT_WRITE_D/PT_READ_D. Otherwise we will return zero | |
477 | to indicate failure. */ | |
478 | if (errno != EINVAL) | |
479 | return 0; | |
480 | } | |
481 | #endif | |
482 | { | |
483 | union | |
484 | { | |
485 | PTRACE_TYPE_RET word; | |
4b8a1a28 | 486 | gdb_byte byte[sizeof (PTRACE_TYPE_RET)]; |
f929a579 AC |
487 | } buffer; |
488 | ULONGEST rounded_offset; | |
489 | LONGEST partial_len; | |
4b8a1a28 | 490 | |
cb85a953 AC |
491 | /* Round the start offset down to the next long word |
492 | boundary. */ | |
f929a579 | 493 | rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET); |
4b8a1a28 | 494 | |
cb85a953 AC |
495 | /* Since ptrace will transfer a single word starting at that |
496 | rounded_offset the partial_len needs to be adjusted down to | |
497 | that (remember this function only does a single transfer). | |
498 | Should the required length be even less, adjust it down | |
499 | again. */ | |
500 | partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset; | |
501 | if (partial_len > len) | |
f929a579 | 502 | partial_len = len; |
4b8a1a28 | 503 | |
f929a579 AC |
504 | if (writebuf) |
505 | { | |
cb85a953 AC |
506 | /* If OFFSET:PARTIAL_LEN is smaller than |
507 | ROUNDED_OFFSET:WORDSIZE then a read/modify write will | |
508 | be needed. Read in the entire word. */ | |
f929a579 | 509 | if (rounded_offset < offset |
cb85a953 AC |
510 | || (offset + partial_len |
511 | < rounded_offset + sizeof (PTRACE_TYPE_RET))) | |
f929a579 | 512 | /* Need part of initial word -- fetch it. */ |
4b8a1a28 MK |
513 | buffer.word = ptrace (PT_READ_I, pid, |
514 | (PTRACE_TYPE_ARG3)(long)rounded_offset, 0); | |
515 | ||
f929a579 AC |
516 | /* Copy data to be written over corresponding part of |
517 | buffer. */ | |
f6ffd89b MK |
518 | memcpy (buffer.byte + (offset - rounded_offset), |
519 | writebuf, partial_len); | |
4b8a1a28 | 520 | |
f929a579 | 521 | errno = 0; |
4b8a1a28 MK |
522 | ptrace (PT_WRITE_D, pid, |
523 | (PTRACE_TYPE_ARG3)(long)rounded_offset, buffer.word); | |
f929a579 AC |
524 | if (errno) |
525 | { | |
526 | /* Using the appropriate one (I or D) is necessary for | |
527 | Gould NP1, at least. */ | |
528 | errno = 0; | |
4b8a1a28 MK |
529 | ptrace (PT_WRITE_I, pid, |
530 | (PTRACE_TYPE_ARG3)(long)rounded_offset, buffer.word); | |
f929a579 AC |
531 | if (errno) |
532 | return 0; | |
533 | } | |
534 | } | |
4b8a1a28 | 535 | |
f929a579 AC |
536 | if (readbuf) |
537 | { | |
538 | errno = 0; | |
4b8a1a28 MK |
539 | buffer.word = ptrace (PT_READ_I, pid, |
540 | (PTRACE_TYPE_ARG3)(long)rounded_offset, 0); | |
f929a579 AC |
541 | if (errno) |
542 | return 0; | |
543 | /* Copy appropriate bytes out of the buffer. */ | |
544 | memcpy (readbuf, buffer.byte + (offset - rounded_offset), | |
545 | partial_len); | |
546 | } | |
4b8a1a28 | 547 | |
f929a579 AC |
548 | return partial_len; |
549 | } | |
5bf970f9 AC |
550 | |
551 | case TARGET_OBJECT_UNWIND_TABLE: | |
552 | return -1; | |
553 | ||
554 | case TARGET_OBJECT_AUXV: | |
555 | return -1; | |
556 | ||
557 | case TARGET_OBJECT_WCOOKIE: | |
558 | return -1; | |
559 | ||
560 | default: | |
561 | return -1; | |
562 | } | |
563 | } | |
564 | ||
4b8a1a28 | 565 | /* Return non-zero if the thread specified by PTID is alive. */ |
c7c14b96 MK |
566 | |
567 | static int | |
568 | inf_ptrace_thread_alive (ptid_t ptid) | |
569 | { | |
4b8a1a28 MK |
570 | /* ??? Is kill the right way to do this? */ |
571 | return (kill (ptid_get_pid (ptid), 0) != -1); | |
c7c14b96 MK |
572 | } |
573 | ||
574 | /* Print status information about what we're accessing. */ | |
575 | ||
576 | static void | |
577 | inf_ptrace_files_info (struct target_ops *ignore) | |
578 | { | |
4b8a1a28 MK |
579 | printf_filtered (_("\tUsing the running image of %s %s.\n"), |
580 | attach_flag ? "attached" : "child", | |
581 | target_pid_to_str (inferior_ptid)); | |
5bf970f9 AC |
582 | } |
583 | ||
8785ced0 MK |
584 | /* Create a prototype ptrace target. The client can override it with |
585 | local methods. */ | |
586 | ||
5bf970f9 AC |
587 | struct target_ops * |
588 | inf_ptrace_target (void) | |
589 | { | |
590 | struct target_ops *t = inf_child_target (); | |
8785ced0 | 591 | |
5bf970f9 | 592 | t->to_attach = inf_ptrace_attach; |
5bf970f9 AC |
593 | t->to_detach = inf_ptrace_detach; |
594 | t->to_resume = inf_ptrace_resume; | |
595 | t->to_wait = inf_ptrace_wait; | |
5bf970f9 | 596 | t->to_files_info = inf_ptrace_files_info; |
4b8a1a28 | 597 | t->to_kill = inf_ptrace_kill; |
5bf970f9 | 598 | t->to_create_inferior = inf_ptrace_create_inferior; |
735f54b4 MK |
599 | #ifdef PT_GET_PROCESS_STATE |
600 | t->to_follow_fork = inf_ptrace_follow_fork; | |
e4ef629d MK |
601 | t->to_post_startup_inferior = inf_ptrace_post_startup_inferior; |
602 | t->to_post_attach = inf_ptrace_post_attach; | |
735f54b4 | 603 | #endif |
5bf970f9 | 604 | t->to_mourn_inferior = inf_ptrace_mourn_inferior; |
5bf970f9 | 605 | t->to_thread_alive = inf_ptrace_thread_alive; |
4b8a1a28 | 606 | t->to_pid_to_str = normal_pid_to_str; |
5bf970f9 | 607 | t->to_stop = inf_ptrace_stop; |
c7c14b96 | 608 | t->to_xfer_partial = inf_ptrace_xfer_partial; |
8785ced0 | 609 | |
c7c14b96 | 610 | ptrace_ops_hack = t; |
8785ced0 MK |
611 | return t; |
612 | } | |
613 | \f | |
614 | ||
4b8a1a28 | 615 | /* Pointer to a function that returns the offset within the user area |
8785ced0 MK |
616 | where a particular register is stored. */ |
617 | static CORE_ADDR (*inf_ptrace_register_u_offset)(int); | |
618 | ||
619 | /* Fetch register REGNUM from the inferior. */ | |
620 | ||
621 | static void | |
622 | inf_ptrace_fetch_register (int regnum) | |
623 | { | |
624 | CORE_ADDR addr; | |
625 | size_t size; | |
626 | PTRACE_TYPE_RET *buf; | |
627 | int pid, i; | |
628 | ||
10d6c8cd DJ |
629 | if (CANNOT_FETCH_REGISTER (regnum)) |
630 | { | |
631 | regcache_raw_supply (current_regcache, regnum, NULL); | |
632 | return; | |
633 | } | |
634 | ||
8785ced0 | 635 | /* Cater for systems like GNU/Linux, that implement threads as |
10d6c8cd | 636 | separate processes. */ |
8785ced0 MK |
637 | pid = ptid_get_lwp (inferior_ptid); |
638 | if (pid == 0) | |
639 | pid = ptid_get_pid (inferior_ptid); | |
640 | ||
641 | /* This isn't really an address, but ptrace thinks of it as one. */ | |
642 | addr = inf_ptrace_register_u_offset (regnum); | |
643 | size = register_size (current_gdbarch, regnum); | |
644 | ||
645 | gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0); | |
646 | buf = alloca (size); | |
647 | ||
10d6c8cd | 648 | /* Read the register contents from the inferior a chunk at a time. */ |
8785ced0 MK |
649 | for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++) |
650 | { | |
651 | errno = 0; | |
4b8a1a28 | 652 | buf[i] = ptrace (PT_READ_U, pid, (PTRACE_TYPE_ARG3)addr, 0); |
8785ced0 | 653 | if (errno != 0) |
4b8a1a28 MK |
654 | error (_("Couldn't read register %s (#%d): %s."), |
655 | REGISTER_NAME (regnum), regnum, safe_strerror (errno)); | |
8785ced0 MK |
656 | |
657 | addr += sizeof (PTRACE_TYPE_RET); | |
658 | } | |
659 | regcache_raw_supply (current_regcache, regnum, buf); | |
660 | } | |
661 | ||
662 | /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this | |
663 | for all registers. */ | |
664 | ||
665 | static void | |
666 | inf_ptrace_fetch_registers (int regnum) | |
667 | { | |
668 | if (regnum == -1) | |
669 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
670 | inf_ptrace_fetch_register (regnum); | |
671 | else | |
672 | inf_ptrace_fetch_register (regnum); | |
673 | } | |
674 | ||
675 | /* Store register REGNUM into the inferior. */ | |
676 | ||
677 | static void | |
678 | inf_ptrace_store_register (int regnum) | |
679 | { | |
680 | CORE_ADDR addr; | |
681 | size_t size; | |
682 | PTRACE_TYPE_RET *buf; | |
683 | int pid, i; | |
684 | ||
10d6c8cd DJ |
685 | if (CANNOT_STORE_REGISTER (regnum)) |
686 | return; | |
687 | ||
8785ced0 | 688 | /* Cater for systems like GNU/Linux, that implement threads as |
10d6c8cd | 689 | separate processes. */ |
8785ced0 MK |
690 | pid = ptid_get_lwp (inferior_ptid); |
691 | if (pid == 0) | |
692 | pid = ptid_get_pid (inferior_ptid); | |
693 | ||
694 | /* This isn't really an address, but ptrace thinks of it as one. */ | |
695 | addr = inf_ptrace_register_u_offset (regnum); | |
696 | size = register_size (current_gdbarch, regnum); | |
697 | ||
698 | gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0); | |
699 | buf = alloca (size); | |
700 | ||
10d6c8cd | 701 | /* Write the register contents into the inferior a chunk at a time. */ |
8785ced0 MK |
702 | regcache_raw_collect (current_regcache, regnum, buf); |
703 | for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++) | |
704 | { | |
705 | errno = 0; | |
4b8a1a28 | 706 | ptrace (PT_WRITE_U, pid, (PTRACE_TYPE_ARG3)addr, buf[i]); |
8785ced0 | 707 | if (errno != 0) |
4b8a1a28 MK |
708 | error (_("Couldn't write register %s (#%d): %s."), |
709 | REGISTER_NAME (regnum), regnum, safe_strerror (errno)); | |
8785ced0 MK |
710 | |
711 | addr += sizeof (PTRACE_TYPE_RET); | |
712 | } | |
713 | } | |
714 | ||
715 | /* Store register REGNUM back into the inferior. If REGNUM is -1, do | |
716 | this for all registers. */ | |
717 | ||
718 | void | |
719 | inf_ptrace_store_registers (int regnum) | |
720 | { | |
721 | if (regnum == -1) | |
722 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
723 | inf_ptrace_store_register (regnum); | |
724 | else | |
725 | inf_ptrace_store_register (regnum); | |
726 | } | |
727 | ||
728 | /* Create a "traditional" ptrace target. REGISTER_U_OFFSET should be | |
729 | a function returning the offset within the user area where a | |
730 | particular register is stored. */ | |
731 | ||
732 | struct target_ops * | |
733 | inf_ptrace_trad_target (CORE_ADDR (*register_u_offset)(int)) | |
734 | { | |
735 | struct target_ops *t = inf_ptrace_target(); | |
736 | ||
737 | gdb_assert (register_u_offset); | |
738 | inf_ptrace_register_u_offset = register_u_offset; | |
739 | t->to_fetch_registers = inf_ptrace_fetch_registers; | |
740 | t->to_store_registers = inf_ptrace_store_registers; | |
741 | ||
5bf970f9 AC |
742 | return t; |
743 | } |