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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" | |
23 | #include <sys/wait.h> | |
da6d8c04 DJ |
24 | |
25 | #include <stdio.h> | |
26 | #include <sys/param.h> | |
27 | #include <sys/dir.h> | |
28 | #include <sys/ptrace.h> | |
29 | #include <sys/user.h> | |
30 | #include <signal.h> | |
31 | #include <sys/ioctl.h> | |
32 | #include <fcntl.h> | |
d07c63e7 | 33 | #include <string.h> |
0a30fbc4 DJ |
34 | #include <stdlib.h> |
35 | #include <unistd.h> | |
da6d8c04 | 36 | |
d844cde6 | 37 | #define PTRACE_ARG3_TYPE long |
da6d8c04 | 38 | #define PTRACE_XFER_TYPE int |
da6d8c04 DJ |
39 | |
40 | extern int errno; | |
0a30fbc4 DJ |
41 | extern int num_regs; |
42 | extern int regmap[]; | |
da6d8c04 DJ |
43 | |
44 | /* Start an inferior process and returns its pid. | |
45 | ALLARGS is a vector of program-name and args. */ | |
46 | ||
47 | int | |
48 | create_inferior (char *program, char **allargs) | |
49 | { | |
50 | int pid; | |
51 | ||
52 | pid = fork (); | |
53 | if (pid < 0) | |
54 | perror_with_name ("fork"); | |
55 | ||
56 | if (pid == 0) | |
57 | { | |
58 | ptrace (PTRACE_TRACEME, 0, 0, 0); | |
59 | ||
60 | execv (program, allargs); | |
61 | ||
62 | fprintf (stderr, "Cannot exec %s: %s.\n", program, | |
d07c63e7 | 63 | strerror (errno)); |
da6d8c04 DJ |
64 | fflush (stderr); |
65 | _exit (0177); | |
66 | } | |
67 | ||
68 | return pid; | |
69 | } | |
70 | ||
71 | /* Attach to an inferior process. */ | |
72 | ||
73 | int | |
74 | myattach (int pid) | |
75 | { | |
76 | if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0) | |
77 | { | |
78 | fprintf (stderr, "Cannot attach to process %d: %s (%d)\n", pid, | |
79 | errno < sys_nerr ? sys_errlist[errno] : "unknown error", | |
80 | errno); | |
81 | fflush (stderr); | |
82 | _exit (0177); | |
83 | } | |
84 | ||
85 | return 0; | |
86 | } | |
87 | ||
88 | /* Kill the inferior process. Make us have no inferior. */ | |
89 | ||
90 | void | |
91 | kill_inferior (void) | |
92 | { | |
93 | if (inferior_pid == 0) | |
94 | return; | |
95 | ptrace (PTRACE_KILL, inferior_pid, 0, 0); | |
96 | wait (0); | |
da6d8c04 DJ |
97 | } |
98 | ||
99 | /* Return nonzero if the given thread is still alive. */ | |
100 | int | |
101 | mythread_alive (int pid) | |
102 | { | |
103 | return 1; | |
104 | } | |
105 | ||
106 | /* Wait for process, returns status */ | |
107 | ||
108 | unsigned char | |
109 | mywait (char *status) | |
110 | { | |
111 | int pid; | |
e5f1222d | 112 | int w; |
da6d8c04 DJ |
113 | |
114 | enable_async_io (); | |
e5f1222d | 115 | pid = waitpid (inferior_pid, &w, 0); |
da6d8c04 DJ |
116 | disable_async_io (); |
117 | if (pid != inferior_pid) | |
118 | perror_with_name ("wait"); | |
119 | ||
120 | if (WIFEXITED (w)) | |
121 | { | |
122 | fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w)); | |
123 | *status = 'W'; | |
124 | return ((unsigned char) WEXITSTATUS (w)); | |
125 | } | |
126 | else if (!WIFSTOPPED (w)) | |
127 | { | |
128 | fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w)); | |
129 | *status = 'X'; | |
130 | return ((unsigned char) WTERMSIG (w)); | |
131 | } | |
132 | ||
133 | fetch_inferior_registers (0); | |
134 | ||
135 | *status = 'T'; | |
136 | return ((unsigned char) WSTOPSIG (w)); | |
137 | } | |
138 | ||
139 | /* Resume execution of the inferior process. | |
140 | If STEP is nonzero, single-step it. | |
141 | If SIGNAL is nonzero, give it that signal. */ | |
142 | ||
143 | void | |
144 | myresume (int step, int signal) | |
145 | { | |
146 | errno = 0; | |
147 | ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal); | |
148 | if (errno) | |
149 | perror_with_name ("ptrace"); | |
150 | } | |
151 | ||
0a30fbc4 | 152 | #define REGISTER_RAW_SIZE(regno) register_size((regno)) |
da6d8c04 DJ |
153 | |
154 | int | |
0a30fbc4 | 155 | register_addr (int regnum) |
da6d8c04 DJ |
156 | { |
157 | int addr; | |
158 | ||
0a30fbc4 | 159 | if (regnum < 0 || regnum >= num_regs) |
da6d8c04 DJ |
160 | error ("Invalid register number %d.", regnum); |
161 | ||
0a30fbc4 | 162 | addr = regmap[regnum]; |
da6d8c04 DJ |
163 | if (addr == -1) |
164 | addr = 0; | |
165 | ||
166 | return addr; | |
167 | } | |
168 | ||
da6d8c04 DJ |
169 | /* Fetch one register. */ |
170 | ||
171 | static void | |
172 | fetch_register (int regno) | |
173 | { | |
174 | CORE_ADDR regaddr; | |
175 | register int i; | |
176 | ||
0a30fbc4 DJ |
177 | if (regno >= num_regs) |
178 | return; | |
179 | if (cannot_fetch_register (regno)) | |
180 | return; | |
da6d8c04 | 181 | |
0a30fbc4 DJ |
182 | regaddr = register_addr (regno); |
183 | if (regaddr == -1) | |
184 | return; | |
da6d8c04 DJ |
185 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) |
186 | { | |
187 | errno = 0; | |
0a30fbc4 | 188 | *(PTRACE_XFER_TYPE *) (register_data (regno) + i) = |
da6d8c04 DJ |
189 | ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0); |
190 | regaddr += sizeof (PTRACE_XFER_TYPE); | |
191 | if (errno != 0) | |
192 | { | |
193 | /* Warning, not error, in case we are attached; sometimes the | |
194 | kernel doesn't let us at the registers. */ | |
195 | char *err = strerror (errno); | |
196 | char *msg = alloca (strlen (err) + 128); | |
197 | sprintf (msg, "reading register %d: %s", regno, err); | |
198 | error (msg); | |
199 | goto error_exit; | |
200 | } | |
201 | } | |
202 | error_exit:; | |
203 | } | |
204 | ||
205 | /* Fetch all registers, or just one, from the child process. */ | |
206 | ||
207 | void | |
208 | fetch_inferior_registers (int regno) | |
209 | { | |
210 | if (regno == -1 || regno == 0) | |
0a30fbc4 | 211 | for (regno = 0; regno < num_regs; regno++) |
da6d8c04 DJ |
212 | fetch_register (regno); |
213 | else | |
214 | fetch_register (regno); | |
215 | } | |
216 | ||
217 | /* Store our register values back into the inferior. | |
218 | If REGNO is -1, do this for all registers. | |
219 | Otherwise, REGNO specifies which register (so we can save time). */ | |
220 | ||
221 | void | |
222 | store_inferior_registers (int regno) | |
223 | { | |
224 | CORE_ADDR regaddr; | |
225 | int i; | |
da6d8c04 DJ |
226 | |
227 | if (regno >= 0) | |
228 | { | |
0a30fbc4 DJ |
229 | if (regno >= num_regs) |
230 | return; | |
231 | ||
232 | if (cannot_store_register (regno)) | |
233 | return; | |
234 | ||
235 | regaddr = register_addr (regno); | |
236 | if (regaddr == -1) | |
da6d8c04 | 237 | return; |
da6d8c04 | 238 | errno = 0; |
0a30fbc4 | 239 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int)) |
da6d8c04 | 240 | { |
0a30fbc4 DJ |
241 | errno = 0; |
242 | ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, | |
243 | *(int *) (register_data (regno) + i)); | |
da6d8c04 DJ |
244 | if (errno != 0) |
245 | { | |
0a30fbc4 DJ |
246 | /* Warning, not error, in case we are attached; sometimes the |
247 | kernel doesn't let us at the registers. */ | |
248 | char *err = strerror (errno); | |
249 | char *msg = alloca (strlen (err) + 128); | |
250 | sprintf (msg, "writing register %d: %s", | |
251 | regno, err); | |
252 | error (msg); | |
253 | return; | |
da6d8c04 | 254 | } |
0a30fbc4 | 255 | regaddr += sizeof (int); |
da6d8c04 | 256 | } |
da6d8c04 DJ |
257 | } |
258 | else | |
0a30fbc4 | 259 | for (regno = 0; regno < num_regs; regno++) |
da6d8c04 DJ |
260 | store_inferior_registers (regno); |
261 | } | |
262 | ||
da6d8c04 DJ |
263 | /* Copy LEN bytes from inferior's memory starting at MEMADDR |
264 | to debugger memory starting at MYADDR. */ | |
265 | ||
266 | void | |
267 | read_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len) | |
268 | { | |
269 | register int i; | |
270 | /* Round starting address down to longword boundary. */ | |
271 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
272 | /* Round ending address up; get number of longwords that makes. */ | |
273 | register int count | |
274 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) | |
275 | / sizeof (PTRACE_XFER_TYPE); | |
276 | /* Allocate buffer of that many longwords. */ | |
277 | register PTRACE_XFER_TYPE *buffer | |
278 | = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); | |
279 | ||
280 | /* Read all the longwords */ | |
281 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
282 | { | |
d844cde6 | 283 | buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, 0); |
da6d8c04 DJ |
284 | } |
285 | ||
286 | /* Copy appropriate bytes out of the buffer. */ | |
287 | memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len); | |
288 | } | |
289 | ||
290 | /* Copy LEN bytes of data from debugger memory at MYADDR | |
291 | to inferior's memory at MEMADDR. | |
292 | On failure (cannot write the inferior) | |
293 | returns the value of errno. */ | |
294 | ||
295 | int | |
296 | write_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len) | |
297 | { | |
298 | register int i; | |
299 | /* Round starting address down to longword boundary. */ | |
300 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
301 | /* Round ending address up; get number of longwords that makes. */ | |
302 | register int count | |
303 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE); | |
304 | /* Allocate buffer of that many longwords. */ | |
305 | register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); | |
306 | extern int errno; | |
307 | ||
308 | /* Fill start and end extra bytes of buffer with existing memory data. */ | |
309 | ||
d844cde6 DJ |
310 | buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid, |
311 | (PTRACE_ARG3_TYPE) addr, 0); | |
da6d8c04 DJ |
312 | |
313 | if (count > 1) | |
314 | { | |
315 | buffer[count - 1] | |
316 | = ptrace (PTRACE_PEEKTEXT, inferior_pid, | |
d844cde6 DJ |
317 | (PTRACE_ARG3_TYPE) (addr + (count - 1) |
318 | * sizeof (PTRACE_XFER_TYPE)), | |
319 | 0); | |
da6d8c04 DJ |
320 | } |
321 | ||
322 | /* Copy data to be written over corresponding part of buffer */ | |
323 | ||
324 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len); | |
325 | ||
326 | /* Write the entire buffer. */ | |
327 | ||
328 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
329 | { | |
330 | errno = 0; | |
d844cde6 | 331 | ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]); |
da6d8c04 DJ |
332 | if (errno) |
333 | return errno; | |
334 | } | |
335 | ||
336 | return 0; | |
337 | } | |
338 | \f | |
339 | void | |
340 | initialize_low (void) | |
341 | { | |
0a30fbc4 | 342 | init_registers (); |
da6d8c04 | 343 | } |