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bd5635a1 RP |
1 | /* Low level Unix child interface to ptrace, for GDB when running under Unix. |
2 | Copyright (C) 1988, 1989, 1990, 1991 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GDB. | |
5 | ||
6 | GDB is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 1, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GDB is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GDB; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | #include <stdio.h> | |
21 | #include "defs.h" | |
22 | #include "param.h" | |
23 | #include "frame.h" | |
24 | #include "inferior.h" | |
25 | #include "target.h" | |
26 | ||
27 | #ifdef USG | |
28 | #include <sys/types.h> | |
29 | #endif | |
30 | ||
31 | #include <sys/param.h> | |
32 | #include <sys/dir.h> | |
33 | #include <signal.h> | |
34 | #include <sys/ioctl.h> | |
35 | #include <sys/ptrace.h> | |
36 | #if !defined (PT_KILL) | |
37 | #define PT_KILL 8 | |
38 | #define PT_STEP 9 | |
39 | #define PT_CONTINUE 7 | |
40 | #define PT_READ_U 3 | |
41 | #define PT_WRITE_U 6 | |
42 | #define PT_READ_I 1 | |
43 | #define PT_WRITE_I 4 | |
44 | /* The Following Change is for a Sun */ | |
45 | #define PT_WRITE_D 4 | |
46 | #endif /* No PT_KILL. */ | |
47 | ||
48 | #ifndef PT_ATTACH | |
49 | #define PT_ATTACH PTRACE_ATTACH | |
50 | #endif | |
51 | #ifndef PT_DETACH | |
52 | #define PT_DETACH PTRACE_DETACH | |
53 | #endif | |
54 | ||
55 | #include "gdbcore.h" | |
56 | #include <sys/user.h> /* After a.out.h */ | |
57 | #include <sys/file.h> | |
58 | #include <sys/stat.h> | |
59 | \f | |
60 | /* This function simply calls ptrace with the given arguments. | |
61 | It exists so that all calls to ptrace are isolated in this | |
62 | machine-dependent file. */ | |
63 | int | |
64 | call_ptrace (request, pid, addr, data) | |
65 | int request, pid, *addr, data; | |
66 | { | |
67 | return ptrace (request, pid, addr, data); | |
68 | } | |
69 | ||
70 | #ifdef DEBUG_PTRACE | |
71 | /* For the rest of the file, use an extra level of indirection */ | |
72 | /* This lets us breakpoint usefully on call_ptrace. */ | |
73 | #define ptrace call_ptrace | |
74 | #endif | |
75 | ||
76 | /* This is used when GDB is exiting. It gives less chance of error.*/ | |
77 | ||
78 | void | |
79 | kill_inferior_fast () | |
80 | { | |
81 | if (inferior_pid == 0) | |
82 | return; | |
83 | ptrace (PT_KILL, inferior_pid, 0, 0); | |
84 | wait ((int *)0); | |
85 | } | |
86 | ||
87 | void | |
88 | kill_inferior (args, from_tty) | |
89 | char *args; | |
90 | int from_tty; | |
91 | { | |
92 | kill_inferior_fast (); | |
93 | target_mourn_inferior (); | |
94 | } | |
95 | ||
96 | /* Resume execution of the inferior process. | |
97 | If STEP is nonzero, single-step it. | |
98 | If SIGNAL is nonzero, give it that signal. */ | |
99 | ||
100 | void | |
101 | child_resume (step, signal) | |
102 | int step; | |
103 | int signal; | |
104 | { | |
105 | errno = 0; | |
106 | /* An address of (int *)1 tells it to continue from where it was. | |
107 | (If GDB wanted it to start some other way, we have already written | |
108 | a new PC value to the child.) */ | |
109 | if (step) | |
110 | { | |
111 | #if defined (NO_SINGLE_STEP) | |
112 | single_step (signal); | |
113 | #else /* Have single step. */ | |
114 | ptrace (PT_STEP, inferior_pid, (int *)1, signal); | |
115 | #endif /* Have single step. */ | |
116 | } | |
117 | else | |
118 | ptrace (PT_CONTINUE, inferior_pid, (int *)1, signal); | |
119 | if (errno) | |
120 | perror_with_name ("ptrace"); | |
121 | } | |
122 | \f | |
123 | #ifdef ATTACH_DETACH | |
124 | /* Nonzero if we are debugging an attached process rather than | |
125 | an inferior. */ | |
126 | extern int attach_flag; | |
127 | ||
128 | /* Start debugging the process whose number is PID. */ | |
129 | int | |
130 | attach (pid) | |
131 | int pid; | |
132 | { | |
133 | errno = 0; | |
134 | ptrace (PT_ATTACH, pid, 0, 0); | |
135 | if (errno) | |
136 | perror_with_name ("ptrace"); | |
137 | attach_flag = 1; | |
138 | return pid; | |
139 | } | |
140 | ||
141 | /* Stop debugging the process whose number is PID | |
142 | and continue it with signal number SIGNAL. | |
143 | SIGNAL = 0 means just continue it. */ | |
144 | ||
145 | void | |
146 | detach (signal) | |
147 | int signal; | |
148 | { | |
149 | errno = 0; | |
150 | ptrace (PT_DETACH, inferior_pid, 1, signal); | |
151 | if (errno) | |
152 | perror_with_name ("ptrace"); | |
153 | attach_flag = 0; | |
154 | } | |
155 | #endif /* ATTACH_DETACH */ | |
156 | \f | |
157 | #if !defined (FETCH_INFERIOR_REGISTERS) | |
158 | ||
159 | /* KERNEL_U_ADDR is the amount to subtract from u.u_ar0 | |
160 | to get the offset in the core file of the register values. */ | |
161 | #if defined (KERNEL_U_ADDR_BSD) | |
162 | /* Get kernel_u_addr using BSD-style nlist(). */ | |
163 | CORE_ADDR kernel_u_addr; | |
164 | ||
165 | void | |
166 | _initialize_kernel_u_addr () | |
167 | { | |
168 | struct nlist names[2]; | |
169 | ||
170 | names[0].n_un.n_name = "_u"; | |
171 | names[1].n_un.n_name = NULL; | |
172 | if (nlist ("/vmunix", names) == 0) | |
173 | kernel_u_addr = names[0].n_value; | |
174 | else | |
175 | fatal ("Unable to get kernel u area address."); | |
176 | } | |
177 | #endif /* KERNEL_U_ADDR_BSD. */ | |
178 | ||
179 | #if defined (KERNEL_U_ADDR_HPUX) | |
180 | /* Get kernel_u_addr using HPUX-style nlist(). */ | |
181 | CORE_ADDR kernel_u_addr; | |
182 | ||
183 | struct hpnlist { | |
184 | char * n_name; | |
185 | long n_value; | |
186 | unsigned char n_type; | |
187 | unsigned char n_length; | |
188 | short n_almod; | |
189 | short n_unused; | |
190 | }; | |
191 | static struct hpnlist nl[] = {{ "_u", -1, }, { (char *) 0, }}; | |
192 | ||
193 | /* read the value of the u area from the hp-ux kernel */ | |
194 | void _initialize_kernel_u_addr () | |
195 | { | |
196 | struct user u; | |
197 | nlist ("/hp-ux", &nl); | |
198 | kernel_u_addr = nl[0].n_value; | |
199 | } | |
200 | #endif /* KERNEL_U_ADDR_HPUX. */ | |
201 | ||
202 | #if !defined (offsetof) | |
203 | #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) | |
204 | #endif | |
205 | ||
206 | /* U_REGS_OFFSET is the offset of the registers within the u area. */ | |
207 | #if !defined (U_REGS_OFFSET) | |
208 | #define U_REGS_OFFSET \ | |
209 | ptrace (PT_READ_U, inferior_pid, \ | |
210 | (int *)(offsetof (struct user, u_ar0)), 0) - KERNEL_U_ADDR | |
211 | #endif | |
212 | ||
213 | /* Fetch one register. */ | |
214 | static void | |
215 | fetch_register (regno) | |
216 | int regno; | |
217 | { | |
218 | register unsigned int regaddr; | |
219 | char buf[MAX_REGISTER_RAW_SIZE]; | |
220 | register int i; | |
221 | ||
222 | /* Offset of registers within the u area. */ | |
223 | unsigned int offset = U_REGS_OFFSET; | |
224 | ||
225 | regaddr = register_addr (regno, offset); | |
226 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int)) | |
227 | { | |
228 | *(int *) &buf[i] = ptrace (PT_READ_U, inferior_pid, (int *)regaddr, 0); | |
229 | regaddr += sizeof (int); | |
230 | } | |
231 | supply_register (regno, buf); | |
232 | } | |
233 | ||
234 | /* Fetch all registers, or just one, from the child process. | |
235 | We should check for errors, but we don't. FIXME. */ | |
236 | ||
237 | int | |
238 | fetch_inferior_registers (regno) | |
239 | int regno; | |
240 | { | |
241 | if (regno == -1) | |
242 | for (regno = 0; regno < NUM_REGS; regno++) | |
243 | fetch_register (regno); | |
244 | else | |
245 | fetch_register (regno); | |
246 | return 0; | |
247 | } | |
248 | ||
249 | /* Registers we shouldn't try to store. */ | |
250 | #if !defined (CANNOT_STORE_REGISTER) | |
251 | #define CANNOT_STORE_REGISTER(regno) 0 | |
252 | #endif | |
253 | ||
254 | /* Store our register values back into the inferior. | |
255 | If REGNO is -1, do this for all registers. | |
256 | Otherwise, REGNO specifies which register (so we can save time). */ | |
257 | ||
258 | int | |
259 | store_inferior_registers (regno) | |
260 | int regno; | |
261 | { | |
262 | register unsigned int regaddr; | |
263 | char buf[80]; | |
264 | extern char registers[]; | |
265 | register int i; | |
266 | int result = 0; | |
267 | ||
268 | unsigned int offset = U_REGS_OFFSET; | |
269 | ||
270 | if (regno >= 0) | |
271 | { | |
272 | regaddr = register_addr (regno, offset); | |
273 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int)) | |
274 | { | |
275 | errno = 0; | |
276 | ptrace (PT_WRITE_U, inferior_pid, (int *)regaddr, | |
277 | *(int *) ®isters[REGISTER_BYTE (regno) + i]); | |
278 | if (errno != 0) | |
279 | { | |
280 | sprintf (buf, "writing register number %d(%d)", regno, i); | |
281 | perror_with_name (buf); | |
282 | result = -1; | |
283 | } | |
284 | regaddr += sizeof(int); | |
285 | } | |
286 | } | |
287 | else | |
288 | { | |
289 | for (regno = 0; regno < NUM_REGS; regno++) | |
290 | { | |
291 | if (CANNOT_STORE_REGISTER (regno)) | |
292 | continue; | |
293 | regaddr = register_addr (regno, offset); | |
294 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int)) | |
295 | { | |
296 | errno = 0; | |
297 | ptrace (PT_WRITE_U, inferior_pid, (int *)regaddr, | |
298 | *(int *) ®isters[REGISTER_BYTE (regno) + i]); | |
299 | if (errno != 0) | |
300 | { | |
301 | sprintf (buf, "writing register number %d(%d)", regno, i); | |
302 | perror_with_name (buf); | |
303 | result = -1; | |
304 | } | |
305 | regaddr += sizeof(int); | |
306 | } | |
307 | } | |
308 | } | |
309 | return result; | |
310 | } | |
311 | #endif /* !defined (FETCH_INFERIOR_REGISTERS). */ | |
312 | \f | |
313 | /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory | |
314 | in the NEW_SUN_PTRACE case. | |
315 | It ought to be straightforward. But it appears that writing did | |
316 | not write the data that I specified. I cannot understand where | |
317 | it got the data that it actually did write. */ | |
318 | ||
319 | /* Copy LEN bytes to or from inferior's memory starting at MEMADDR | |
320 | to debugger memory starting at MYADDR. Copy to inferior if | |
321 | WRITE is nonzero. | |
322 | ||
323 | Returns the length copied, which is either the LEN argument or zero. | |
324 | This xfer function does not do partial moves, since child_ops | |
325 | doesn't allow memory operations to cross below us in the target stack | |
326 | anyway. */ | |
327 | ||
328 | int | |
329 | child_xfer_memory (memaddr, myaddr, len, write) | |
330 | CORE_ADDR memaddr; | |
331 | char *myaddr; | |
332 | int len; | |
333 | int write; | |
334 | { | |
335 | register int i; | |
336 | /* Round starting address down to longword boundary. */ | |
337 | register CORE_ADDR addr = memaddr & - sizeof (int); | |
338 | /* Round ending address up; get number of longwords that makes. */ | |
339 | register int count | |
340 | = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int); | |
341 | /* Allocate buffer of that many longwords. */ | |
342 | register int *buffer = (int *) alloca (count * sizeof (int)); | |
343 | ||
344 | if (write) | |
345 | { | |
346 | /* Fill start and end extra bytes of buffer with existing memory data. */ | |
347 | ||
348 | if (addr != memaddr || len < (int)sizeof (int)) { | |
349 | /* Need part of initial word -- fetch it. */ | |
350 | buffer[0] = ptrace (PT_READ_I, inferior_pid, (int *)addr, 0); | |
351 | } | |
352 | ||
353 | if (count > 1) /* FIXME, avoid if even boundary */ | |
354 | { | |
355 | buffer[count - 1] | |
356 | = ptrace (PT_READ_I, inferior_pid, | |
357 | (int *)(addr + (count - 1) * sizeof (int)), 0); | |
358 | } | |
359 | ||
360 | /* Copy data to be written over corresponding part of buffer */ | |
361 | ||
362 | bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len); | |
363 | ||
364 | /* Write the entire buffer. */ | |
365 | ||
366 | for (i = 0; i < count; i++, addr += sizeof (int)) | |
367 | { | |
368 | errno = 0; | |
369 | ptrace (PT_WRITE_D, inferior_pid, (int *)addr, buffer[i]); | |
370 | if (errno) | |
371 | { | |
372 | /* Using the appropriate one (I or D) is necessary for | |
373 | Gould NP1, at least. */ | |
374 | errno = 0; | |
375 | ptrace (PT_WRITE_I, inferior_pid, (int *)addr, buffer[i]); | |
376 | } | |
377 | if (errno) | |
378 | return 0; | |
379 | } | |
380 | } | |
381 | else | |
382 | { | |
383 | /* Read all the longwords */ | |
384 | for (i = 0; i < count; i++, addr += sizeof (int)) | |
385 | { | |
386 | errno = 0; | |
387 | buffer[i] = ptrace (PT_READ_I, inferior_pid, (int *)addr, 0); | |
388 | if (errno) | |
389 | return 0; | |
390 | QUIT; | |
391 | } | |
392 | ||
393 | /* Copy appropriate bytes out of the buffer. */ | |
394 | bcopy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len); | |
395 | } | |
396 | return len; | |
397 | } |