1 /* Low level Unix child interface to ptrace, for GDB when running under Unix.
2 Copyright 1988, 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program 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 2 of the License, or
9 (at your option) any later version.
11 This program 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.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
26 #include <sys/types.h>
29 #include <sys/param.h>
32 #include <sys/ioctl.h>
34 #ifdef PTRACE_IN_WRONG_PLACE
37 #include <sys/ptrace.h>
41 #if !defined (PT_KILL)
51 #endif /* No PT_KILL. */
54 #define PT_ATTACH PTRACE_ATTACH
57 #define PT_DETACH PTRACE_DETACH
66 #if !defined (FETCH_INFERIOR_REGISTERS)
67 #include <sys/user.h> /* Probably need to poke the user structure */
68 #if defined (KERNEL_U_ADDR_BSD)
69 #include <a.out.h> /* For struct nlist */
70 #endif /* KERNEL_U_ADDR_BSD. */
71 #endif /* !FETCH_INFERIOR_REGISTERS */
74 /* This function simply calls ptrace with the given arguments.
75 It exists so that all calls to ptrace are isolated in this
76 machine-dependent file. */
78 call_ptrace (request
, pid
, addr
, data
)
80 PTRACE_ARG3_TYPE addr
;
83 return ptrace (request
, pid
, addr
, data
);
87 /* For the rest of the file, use an extra level of indirection */
88 /* This lets us breakpoint usefully on call_ptrace. */
89 #define ptrace call_ptrace
92 /* This is used when GDB is exiting. It gives less chance of error.*/
97 if (inferior_pid
== 0)
99 ptrace (PT_KILL
, inferior_pid
, (PTRACE_ARG3_TYPE
) 0, 0);
106 kill_inferior_fast ();
107 target_mourn_inferior ();
110 /* Resume execution of the inferior process.
111 If STEP is nonzero, single-step it.
112 If SIGNAL is nonzero, give it that signal. */
115 child_resume (step
, signal
)
121 /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where
122 it was. (If GDB wanted it to start some other way, we have already
123 written a new PC value to the child.)
125 If this system does not support PT_STEP, a higher level function will
126 have called single_step() to transmute the step request into a
127 continue request (by setting breakpoints on all possible successor
128 instructions), so we don't have to worry about that here. */
131 ptrace (PT_STEP
, inferior_pid
, (PTRACE_ARG3_TYPE
) 1, signal
);
133 ptrace (PT_CONTINUE
, inferior_pid
, (PTRACE_ARG3_TYPE
) 1, signal
);
136 perror_with_name ("ptrace");
140 /* Nonzero if we are debugging an attached process rather than
142 extern int attach_flag
;
144 /* Start debugging the process whose number is PID. */
150 ptrace (PT_ATTACH
, pid
, (PTRACE_ARG3_TYPE
) 0, 0);
152 perror_with_name ("ptrace");
157 /* Stop debugging the process whose number is PID
158 and continue it with signal number SIGNAL.
159 SIGNAL = 0 means just continue it. */
166 ptrace (PT_DETACH
, inferior_pid
, (PTRACE_ARG3_TYPE
) 1, signal
);
168 perror_with_name ("ptrace");
171 #endif /* ATTACH_DETACH */
173 #if !defined (FETCH_INFERIOR_REGISTERS)
175 /* KERNEL_U_ADDR is the amount to subtract from u.u_ar0
176 to get the offset in the core file of the register values. */
177 #if defined (KERNEL_U_ADDR_BSD)
178 /* Get kernel_u_addr using BSD-style nlist(). */
179 CORE_ADDR kernel_u_addr
;
182 _initialize_kernel_u_addr ()
184 struct nlist names
[2];
186 names
[0].n_un
.n_name
= "_u";
187 names
[1].n_un
.n_name
= NULL
;
188 if (nlist ("/vmunix", names
) == 0)
189 kernel_u_addr
= names
[0].n_value
;
191 fatal ("Unable to get kernel u area address.");
193 #endif /* KERNEL_U_ADDR_BSD. */
195 #if defined (KERNEL_U_ADDR_HPUX)
196 /* Get kernel_u_addr using HPUX-style nlist(). */
197 CORE_ADDR kernel_u_addr
;
202 unsigned char n_type
;
203 unsigned char n_length
;
207 static struct hpnlist nl
[] = {{ "_u", -1, }, { (char *) 0, }};
209 /* read the value of the u area from the hp-ux kernel */
210 void _initialize_kernel_u_addr ()
212 nlist ("/hp-ux", &nl
);
213 kernel_u_addr
= nl
[0].n_value
;
215 #endif /* KERNEL_U_ADDR_HPUX. */
217 #if !defined (offsetof)
218 #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
221 /* U_REGS_OFFSET is the offset of the registers within the u area. */
222 #if !defined (U_REGS_OFFSET)
223 #define U_REGS_OFFSET \
224 ptrace (PT_READ_U, inferior_pid, \
225 (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \
229 /* Registers we shouldn't try to fetch. */
230 #if !defined (CANNOT_FETCH_REGISTER)
231 #define CANNOT_FETCH_REGISTER(regno) 0
234 /* Fetch one register. */
237 fetch_register (regno
)
240 register unsigned int regaddr
;
241 char buf
[MAX_REGISTER_RAW_SIZE
];
242 char mess
[128]; /* For messages */
245 /* Offset of registers within the u area. */
248 if (CANNOT_FETCH_REGISTER (regno
))
250 bzero (buf
, REGISTER_RAW_SIZE (regno
)); /* Supply zeroes */
251 supply_register (regno
, buf
);
255 offset
= U_REGS_OFFSET
;
257 regaddr
= register_addr (regno
, offset
);
258 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof (int))
261 *(int *) &buf
[i
] = ptrace (PT_READ_U
, inferior_pid
,
262 (PTRACE_ARG3_TYPE
) regaddr
, 0);
263 regaddr
+= sizeof (int);
266 sprintf (mess
, "reading register %s (#%d)", reg_names
[regno
], regno
);
267 perror_with_name (mess
);
270 supply_register (regno
, buf
);
274 /* Fetch all registers, or just one, from the child process. */
277 fetch_inferior_registers (regno
)
281 for (regno
= 0; regno
< NUM_REGS
; regno
++)
282 fetch_register (regno
);
284 fetch_register (regno
);
287 /* Registers we shouldn't try to store. */
288 #if !defined (CANNOT_STORE_REGISTER)
289 #define CANNOT_STORE_REGISTER(regno) 0
292 /* Store our register values back into the inferior.
293 If REGNO is -1, do this for all registers.
294 Otherwise, REGNO specifies which register (so we can save time). */
297 store_inferior_registers (regno
)
300 register unsigned int regaddr
;
302 extern char registers
[];
305 unsigned int offset
= U_REGS_OFFSET
;
309 regaddr
= register_addr (regno
, offset
);
310 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof(int))
313 ptrace (PT_WRITE_U
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
,
314 *(int *) ®isters
[REGISTER_BYTE (regno
) + i
]);
317 sprintf (buf
, "writing register number %d(%d)", regno
, i
);
318 perror_with_name (buf
);
320 regaddr
+= sizeof(int);
325 for (regno
= 0; regno
< NUM_REGS
; regno
++)
327 if (CANNOT_STORE_REGISTER (regno
))
329 regaddr
= register_addr (regno
, offset
);
330 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof(int))
333 ptrace (PT_WRITE_U
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
,
334 *(int *) ®isters
[REGISTER_BYTE (regno
) + i
]);
337 sprintf (buf
, "writing register number %d(%d)", regno
, i
);
338 perror_with_name (buf
);
340 regaddr
+= sizeof(int);
345 #endif /* !defined (FETCH_INFERIOR_REGISTERS). */
347 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
348 in the NEW_SUN_PTRACE case.
349 It ought to be straightforward. But it appears that writing did
350 not write the data that I specified. I cannot understand where
351 it got the data that it actually did write. */
353 /* Copy LEN bytes to or from inferior's memory starting at MEMADDR
354 to debugger memory starting at MYADDR. Copy to inferior if
357 Returns the length copied, which is either the LEN argument or zero.
358 This xfer function does not do partial moves, since child_ops
359 doesn't allow memory operations to cross below us in the target stack
363 child_xfer_memory (memaddr
, myaddr
, len
, write
, target
)
368 struct target_ops
*target
; /* ignored */
371 /* Round starting address down to longword boundary. */
372 register CORE_ADDR addr
= memaddr
& - sizeof (int);
373 /* Round ending address up; get number of longwords that makes. */
375 = (((memaddr
+ len
) - addr
) + sizeof (int) - 1) / sizeof (int);
376 /* Allocate buffer of that many longwords. */
377 register int *buffer
= (int *) alloca (count
* sizeof (int));
381 /* Fill start and end extra bytes of buffer with existing memory data. */
383 if (addr
!= memaddr
|| len
< (int)sizeof (int)) {
384 /* Need part of initial word -- fetch it. */
385 buffer
[0] = ptrace (PT_READ_I
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
,
389 if (count
> 1) /* FIXME, avoid if even boundary */
392 = ptrace (PT_READ_I
, inferior_pid
,
393 (PTRACE_ARG3_TYPE
) (addr
+ (count
- 1) * sizeof (int)),
397 /* Copy data to be written over corresponding part of buffer */
399 memcpy ((char *) buffer
+ (memaddr
& (sizeof (int) - 1)), myaddr
, len
);
401 /* Write the entire buffer. */
403 for (i
= 0; i
< count
; i
++, addr
+= sizeof (int))
406 ptrace (PT_WRITE_D
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
,
410 /* Using the appropriate one (I or D) is necessary for
411 Gould NP1, at least. */
413 ptrace (PT_WRITE_I
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
,
422 /* Read all the longwords */
423 for (i
= 0; i
< count
; i
++, addr
+= sizeof (int))
426 buffer
[i
] = ptrace (PT_READ_I
, inferior_pid
,
427 (PTRACE_ARG3_TYPE
) addr
, 0);
433 /* Copy appropriate bytes out of the buffer. */
434 memcpy (myaddr
, (char *) buffer
+ (memaddr
& (sizeof (int) - 1)), len
);
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