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.
4 This file is part of GDB.
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)
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.
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. */
28 #include <sys/types.h>
31 #include <sys/param.h>
34 #include <sys/ioctl.h>
36 #include <sys/ptrace.h>
39 #if !defined (PT_KILL)
49 #endif /* No PT_KILL. */
52 #define PT_ATTACH PTRACE_ATTACH
55 #define PT_DETACH PTRACE_DETACH
59 #include <sys/user.h> /* After a.out.h */
63 /* This function simply calls ptrace with the given arguments.
64 It exists so that all calls to ptrace are isolated in this
65 machine-dependent file. */
67 call_ptrace (request
, pid
, addr
, data
)
68 int request
, pid
, *addr
, data
;
70 return ptrace (request
, pid
, addr
, data
);
74 /* For the rest of the file, use an extra level of indirection */
75 /* This lets us breakpoint usefully on call_ptrace. */
76 #define ptrace call_ptrace
79 /* This is used when GDB is exiting. It gives less chance of error.*/
84 if (inferior_pid
== 0)
86 ptrace (PT_KILL
, inferior_pid
, 0, 0);
91 kill_inferior (args
, from_tty
)
95 kill_inferior_fast ();
96 target_mourn_inferior ();
99 /* Resume execution of the inferior process.
100 If STEP is nonzero, single-step it.
101 If SIGNAL is nonzero, give it that signal. */
104 child_resume (step
, signal
)
109 /* An address of (int *)1 tells it to continue from where it was.
110 (If GDB wanted it to start some other way, we have already written
111 a new PC value to the child.) */
114 #if defined (NO_SINGLE_STEP)
115 single_step (signal
);
116 #else /* Have single step. */
117 ptrace (PT_STEP
, inferior_pid
, (int *)1, signal
);
118 #endif /* Have single step. */
121 ptrace (PT_CONTINUE
, inferior_pid
, (int *)1, signal
);
123 perror_with_name ("ptrace");
127 /* Nonzero if we are debugging an attached process rather than
129 extern int attach_flag
;
131 /* Start debugging the process whose number is PID. */
137 ptrace (PT_ATTACH
, pid
, 0, 0);
139 perror_with_name ("ptrace");
144 /* Stop debugging the process whose number is PID
145 and continue it with signal number SIGNAL.
146 SIGNAL = 0 means just continue it. */
153 ptrace (PT_DETACH
, inferior_pid
, 1, signal
);
155 perror_with_name ("ptrace");
158 #endif /* ATTACH_DETACH */
160 #if !defined (FETCH_INFERIOR_REGISTERS)
162 /* KERNEL_U_ADDR is the amount to subtract from u.u_ar0
163 to get the offset in the core file of the register values. */
164 #if defined (KERNEL_U_ADDR_BSD)
165 /* Get kernel_u_addr using BSD-style nlist(). */
166 CORE_ADDR kernel_u_addr
;
169 _initialize_kernel_u_addr ()
171 struct nlist names
[2];
173 names
[0].n_un
.n_name
= "_u";
174 names
[1].n_un
.n_name
= NULL
;
175 if (nlist ("/vmunix", names
) == 0)
176 kernel_u_addr
= names
[0].n_value
;
178 fatal ("Unable to get kernel u area address.");
180 #endif /* KERNEL_U_ADDR_BSD. */
182 #if defined (KERNEL_U_ADDR_HPUX)
183 /* Get kernel_u_addr using HPUX-style nlist(). */
184 CORE_ADDR kernel_u_addr
;
189 unsigned char n_type
;
190 unsigned char n_length
;
194 static struct hpnlist nl
[] = {{ "_u", -1, }, { (char *) 0, }};
196 /* read the value of the u area from the hp-ux kernel */
197 void _initialize_kernel_u_addr ()
200 nlist ("/hp-ux", &nl
);
201 kernel_u_addr
= nl
[0].n_value
;
203 #endif /* KERNEL_U_ADDR_HPUX. */
205 #if !defined (offsetof)
206 #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
209 /* U_REGS_OFFSET is the offset of the registers within the u area. */
210 #if !defined (U_REGS_OFFSET)
211 #define U_REGS_OFFSET \
212 ptrace (PT_READ_U, inferior_pid, \
213 (int *)(offsetof (struct user, u_ar0)), 0) - KERNEL_U_ADDR
216 /* Fetch one register. */
218 fetch_register (regno
)
221 register unsigned int regaddr
;
222 char buf
[MAX_REGISTER_RAW_SIZE
];
225 /* Offset of registers within the u area. */
226 unsigned int offset
= U_REGS_OFFSET
;
228 regaddr
= register_addr (regno
, offset
);
229 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof (int))
231 *(int *) &buf
[i
] = ptrace (PT_READ_U
, inferior_pid
, (int *)regaddr
, 0);
232 regaddr
+= sizeof (int);
234 supply_register (regno
, buf
);
237 /* Fetch all registers, or just one, from the child process. */
240 fetch_inferior_registers (regno
)
244 for (regno
= 0; regno
< NUM_REGS
; regno
++)
245 fetch_register (regno
);
247 fetch_register (regno
);
251 /* Registers we shouldn't try to store. */
252 #if !defined (CANNOT_STORE_REGISTER)
253 #define CANNOT_STORE_REGISTER(regno) 0
256 /* Store our register values back into the inferior.
257 If REGNO is -1, do this for all registers.
258 Otherwise, REGNO specifies which register (so we can save time). */
261 store_inferior_registers (regno
)
264 register unsigned int regaddr
;
266 extern char registers
[];
270 unsigned int offset
= U_REGS_OFFSET
;
274 regaddr
= register_addr (regno
, offset
);
275 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof(int))
278 ptrace (PT_WRITE_U
, inferior_pid
, (int *)regaddr
,
279 *(int *) ®isters
[REGISTER_BYTE (regno
) + i
]);
282 sprintf (buf
, "writing register number %d(%d)", regno
, i
);
283 perror_with_name (buf
);
286 regaddr
+= sizeof(int);
291 for (regno
= 0; regno
< NUM_REGS
; regno
++)
293 if (CANNOT_STORE_REGISTER (regno
))
295 regaddr
= register_addr (regno
, offset
);
296 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof(int))
299 ptrace (PT_WRITE_U
, inferior_pid
, (int *)regaddr
,
300 *(int *) ®isters
[REGISTER_BYTE (regno
) + i
]);
303 sprintf (buf
, "writing register number %d(%d)", regno
, i
);
304 perror_with_name (buf
);
307 regaddr
+= sizeof(int);
313 #endif /* !defined (FETCH_INFERIOR_REGISTERS). */
315 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
316 in the NEW_SUN_PTRACE case.
317 It ought to be straightforward. But it appears that writing did
318 not write the data that I specified. I cannot understand where
319 it got the data that it actually did write. */
321 /* Copy LEN bytes to or from inferior's memory starting at MEMADDR
322 to debugger memory starting at MYADDR. Copy to inferior if
325 Returns the length copied, which is either the LEN argument or zero.
326 This xfer function does not do partial moves, since child_ops
327 doesn't allow memory operations to cross below us in the target stack
331 child_xfer_memory (memaddr
, myaddr
, len
, write
)
338 /* Round starting address down to longword boundary. */
339 register CORE_ADDR addr
= memaddr
& - sizeof (int);
340 /* Round ending address up; get number of longwords that makes. */
342 = (((memaddr
+ len
) - addr
) + sizeof (int) - 1) / sizeof (int);
343 /* Allocate buffer of that many longwords. */
344 register int *buffer
= (int *) alloca (count
* sizeof (int));
348 /* Fill start and end extra bytes of buffer with existing memory data. */
350 if (addr
!= memaddr
|| len
< (int)sizeof (int)) {
351 /* Need part of initial word -- fetch it. */
352 buffer
[0] = ptrace (PT_READ_I
, inferior_pid
, (int *)addr
, 0);
355 if (count
> 1) /* FIXME, avoid if even boundary */
358 = ptrace (PT_READ_I
, inferior_pid
,
359 (int *)(addr
+ (count
- 1) * sizeof (int)), 0);
362 /* Copy data to be written over corresponding part of buffer */
364 bcopy (myaddr
, (char *) buffer
+ (memaddr
& (sizeof (int) - 1)), len
);
366 /* Write the entire buffer. */
368 for (i
= 0; i
< count
; i
++, addr
+= sizeof (int))
371 ptrace (PT_WRITE_D
, inferior_pid
, (int *)addr
, buffer
[i
]);
374 /* Using the appropriate one (I or D) is necessary for
375 Gould NP1, at least. */
377 ptrace (PT_WRITE_I
, inferior_pid
, (int *)addr
, buffer
[i
]);
385 /* Read all the longwords */
386 for (i
= 0; i
< count
; i
++, addr
+= sizeof (int))
389 buffer
[i
] = ptrace (PT_READ_I
, inferior_pid
, (int *)addr
, 0);
395 /* Copy appropriate bytes out of the buffer. */
396 bcopy ((char *) buffer
+ (memaddr
& (sizeof (int) - 1)), myaddr
, len
);
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