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>
35 #ifdef PTRACE_IN_WRONG_PLACE
38 #include <sys/ptrace.h>
40 #endif /* NO_PTRACE_H */
42 #if !defined (PT_KILL)
46 #if !defined (PT_STEP)
55 #endif /* No PT_STEP. */
58 #define PT_ATTACH PTRACE_ATTACH
61 #define PT_DETACH PTRACE_DETACH
69 /* Don't think this is used anymore. On the sequent (not sure whether it's
70 dynix or ptx or both), it is included unconditionally by sys/user.h and
71 not protected against multiple inclusion. */
75 #if !defined (FETCH_INFERIOR_REGISTERS)
76 #include <sys/user.h> /* Probably need to poke the user structure */
77 #if defined (KERNEL_U_ADDR_BSD)
78 #include <a.out.h> /* For struct nlist */
79 #endif /* KERNEL_U_ADDR_BSD. */
80 #endif /* !FETCH_INFERIOR_REGISTERS */
83 /* This function simply calls ptrace with the given arguments.
84 It exists so that all calls to ptrace are isolated in this
85 machine-dependent file. */
87 call_ptrace (request
, pid
, addr
, data
)
89 PTRACE_ARG3_TYPE addr
;
92 return ptrace (request
, pid
, addr
, data
93 #if defined (FIVE_ARG_PTRACE)
94 /* Deal with HPUX 8.0 braindamage. We never use the
95 calls which require the fifth argument. */
101 #if defined (DEBUG_PTRACE) || defined (FIVE_ARG_PTRACE)
102 /* For the rest of the file, use an extra level of indirection */
103 /* This lets us breakpoint usefully on call_ptrace. */
104 #define ptrace call_ptrace
110 if (inferior_pid
== 0)
112 /* ptrace PT_KILL only works if process is stopped!!! So stop it with
113 a real signal first, if we can. */
114 kill (inferior_pid
, SIGKILL
);
115 ptrace (PT_KILL
, inferior_pid
, (PTRACE_ARG3_TYPE
) 0, 0);
117 target_mourn_inferior ();
120 /* Resume execution of the inferior process.
121 If STEP is nonzero, single-step it.
122 If SIGNAL is nonzero, give it that signal. */
125 child_resume (pid
, step
, signal
)
128 enum target_signal signal
;
133 /* Resume all threads. */
135 /* This is for Lynx, and should be cleaned up by having Lynx be
136 a separate debugging target, with its own target_resume function. */
137 pid
= PIDGET (inferior_pid
);
139 /* I think this only gets used in the non-threaded case, where "resume
140 all threads" and "resume inferior_pid" are the same. */
144 /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where
145 it was. (If GDB wanted it to start some other way, we have already
146 written a new PC value to the child.)
148 If this system does not support PT_STEP, a higher level function will
149 have called single_step() to transmute the step request into a
150 continue request (by setting breakpoints on all possible successor
151 instructions), so we don't have to worry about that here. */
154 ptrace (PT_STEP
, pid
, (PTRACE_ARG3_TYPE
) 1,
155 target_signal_to_host (signal
));
157 ptrace (PT_CONTINUE
, pid
, (PTRACE_ARG3_TYPE
) 1,
158 target_signal_to_host (signal
));
161 perror_with_name ("ptrace");
165 /* Start debugging the process whose number is PID. */
171 ptrace (PT_ATTACH
, pid
, (PTRACE_ARG3_TYPE
) 0, 0);
173 perror_with_name ("ptrace");
178 /* Stop debugging the process whose number is PID
179 and continue it with signal number SIGNAL.
180 SIGNAL = 0 means just continue it. */
187 ptrace (PT_DETACH
, inferior_pid
, (PTRACE_ARG3_TYPE
) 1, signal
);
189 perror_with_name ("ptrace");
192 #endif /* ATTACH_DETACH */
194 /* Default the type of the ptrace transfer to int. */
195 #ifndef PTRACE_XFER_TYPE
196 #define PTRACE_XFER_TYPE int
199 /* KERNEL_U_ADDR is the amount to subtract from u.u_ar0
200 to get the offset in the core file of the register values. */
201 #if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)
202 /* Get kernel_u_addr using BSD-style nlist(). */
203 CORE_ADDR kernel_u_addr
;
204 #endif /* KERNEL_U_ADDR_BSD. */
207 _initialize_kernel_u_addr ()
209 #if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)
210 struct nlist names
[2];
212 names
[0].n_un
.n_name
= "_u";
213 names
[1].n_un
.n_name
= NULL
;
214 if (nlist ("/vmunix", names
) == 0)
215 kernel_u_addr
= names
[0].n_value
;
217 fatal ("Unable to get kernel u area address.");
218 #endif /* KERNEL_U_ADDR_BSD. */
221 #if !defined (FETCH_INFERIOR_REGISTERS)
223 #if !defined (offsetof)
224 #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
227 /* U_REGS_OFFSET is the offset of the registers within the u area. */
228 #if !defined (U_REGS_OFFSET)
229 #define U_REGS_OFFSET \
230 ptrace (PT_READ_U, inferior_pid, \
231 (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \
235 /* Registers we shouldn't try to fetch. */
236 #if !defined (CANNOT_FETCH_REGISTER)
237 #define CANNOT_FETCH_REGISTER(regno) 0
240 /* Fetch one register. */
243 fetch_register (regno
)
246 register unsigned int regaddr
;
247 char buf
[MAX_REGISTER_RAW_SIZE
];
248 char mess
[128]; /* For messages */
251 /* Offset of registers within the u area. */
254 if (CANNOT_FETCH_REGISTER (regno
))
256 memset (buf
, '\0', REGISTER_RAW_SIZE (regno
)); /* Supply zeroes */
257 supply_register (regno
, buf
);
261 offset
= U_REGS_OFFSET
;
263 regaddr
= register_addr (regno
, offset
);
264 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof (PTRACE_XFER_TYPE
))
267 *(PTRACE_XFER_TYPE
*) &buf
[i
] = ptrace (PT_READ_U
, inferior_pid
,
268 (PTRACE_ARG3_TYPE
) regaddr
, 0);
269 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
272 sprintf (mess
, "reading register %s (#%d)", reg_names
[regno
], regno
);
273 perror_with_name (mess
);
276 supply_register (regno
, buf
);
280 /* Fetch all registers, or just one, from the child process. */
283 fetch_inferior_registers (regno
)
287 for (regno
= 0; regno
< NUM_REGS
; regno
++)
288 fetch_register (regno
);
290 fetch_register (regno
);
293 /* Registers we shouldn't try to store. */
294 #if !defined (CANNOT_STORE_REGISTER)
295 #define CANNOT_STORE_REGISTER(regno) 0
298 /* Store our register values back into the inferior.
299 If REGNO is -1, do this for all registers.
300 Otherwise, REGNO specifies which register (so we can save time). */
303 store_inferior_registers (regno
)
306 register unsigned int regaddr
;
310 unsigned int offset
= U_REGS_OFFSET
;
314 regaddr
= register_addr (regno
, offset
);
315 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof(PTRACE_XFER_TYPE
))
318 ptrace (PT_WRITE_U
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
,
319 *(PTRACE_XFER_TYPE
*) ®isters
[REGISTER_BYTE (regno
) + i
]);
322 sprintf (buf
, "writing register number %d(%d)", regno
, i
);
323 perror_with_name (buf
);
325 regaddr
+= sizeof(PTRACE_XFER_TYPE
);
330 for (regno
= 0; regno
< NUM_REGS
; regno
++)
332 if (CANNOT_STORE_REGISTER (regno
))
334 regaddr
= register_addr (regno
, offset
);
335 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof(PTRACE_XFER_TYPE
))
338 ptrace (PT_WRITE_U
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
,
339 *(PTRACE_XFER_TYPE
*) ®isters
[REGISTER_BYTE (regno
) + i
]);
342 sprintf (buf
, "writing register number %d(%d)", regno
, i
);
343 perror_with_name (buf
);
345 regaddr
+= sizeof(PTRACE_XFER_TYPE
);
350 #endif /* !defined (FETCH_INFERIOR_REGISTERS). */
353 #if !defined (CHILD_XFER_MEMORY)
354 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
355 in the NEW_SUN_PTRACE case.
356 It ought to be straightforward. But it appears that writing did
357 not write the data that I specified. I cannot understand where
358 it got the data that it actually did write. */
360 /* Copy LEN bytes to or from inferior's memory starting at MEMADDR
361 to debugger memory starting at MYADDR. Copy to inferior if
364 Returns the length copied, which is either the LEN argument or zero.
365 This xfer function does not do partial moves, since child_ops
366 doesn't allow memory operations to cross below us in the target stack
370 child_xfer_memory (memaddr
, myaddr
, len
, write
, target
)
375 struct target_ops
*target
; /* ignored */
378 /* Round starting address down to longword boundary. */
379 register CORE_ADDR addr
= memaddr
& - sizeof (PTRACE_XFER_TYPE
);
380 /* Round ending address up; get number of longwords that makes. */
382 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
383 / sizeof (PTRACE_XFER_TYPE
);
384 /* Allocate buffer of that many longwords. */
385 register PTRACE_XFER_TYPE
*buffer
386 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
390 /* Fill start and end extra bytes of buffer with existing memory data. */
392 if (addr
!= memaddr
|| len
< (int) sizeof (PTRACE_XFER_TYPE
)) {
393 /* Need part of initial word -- fetch it. */
394 buffer
[0] = ptrace (PT_READ_I
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
,
398 if (count
> 1) /* FIXME, avoid if even boundary */
401 = ptrace (PT_READ_I
, inferior_pid
,
403 (addr
+ (count
- 1) * sizeof (PTRACE_XFER_TYPE
))),
407 /* Copy data to be written over corresponding part of buffer */
409 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
413 /* Write the entire buffer. */
415 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
418 ptrace (PT_WRITE_D
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
,
422 /* Using the appropriate one (I or D) is necessary for
423 Gould NP1, at least. */
425 ptrace (PT_WRITE_I
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
,
434 /* Read all the longwords */
435 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
438 buffer
[i
] = ptrace (PT_READ_I
, inferior_pid
,
439 (PTRACE_ARG3_TYPE
) addr
, 0);
445 /* Copy appropriate bytes out of the buffer. */
447 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
452 #endif /* !defined (CHILD_XFER_MEMORY). */
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