1 /* Low level Unix child interface to ptrace, for GDB when running under Unix.
2 Copyright 1988, 89, 90, 91, 92, 93, 94, 95, 96, 1998
3 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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. */
26 #include "gdb_string.h"
33 #include <sys/types.h>
36 #include <sys/param.h>
39 #include <sys/ioctl.h>
44 #ifdef HAVE_SYS_PTRACE_H
45 #include <sys/ptrace.h>
49 #if !defined (PT_READ_I)
50 #define PT_READ_I 1 /* Read word from text space */
52 #if !defined (PT_READ_D)
53 #define PT_READ_D 2 /* Read word from data space */
55 #if !defined (PT_READ_U)
56 #define PT_READ_U 3 /* Read word from kernel user struct */
58 #if !defined (PT_WRITE_I)
59 #define PT_WRITE_I 4 /* Write word to text space */
61 #if !defined (PT_WRITE_D)
62 #define PT_WRITE_D 5 /* Write word to data space */
64 #if !defined (PT_WRITE_U)
65 #define PT_WRITE_U 6 /* Write word to kernel user struct */
67 #if !defined (PT_CONTINUE)
68 #define PT_CONTINUE 7 /* Continue after signal */
70 #if !defined (PT_STEP)
71 #define PT_STEP 9 /* Set flag for single stepping */
73 #if !defined (PT_KILL)
74 #define PT_KILL 8 /* Send child a SIGKILL signal */
78 #define PT_ATTACH PTRACE_ATTACH
81 #define PT_DETACH PTRACE_DETACH
89 /* Don't think this is used anymore. On the sequent (not sure whether it's
90 dynix or ptx or both), it is included unconditionally by sys/user.h and
91 not protected against multiple inclusion. */
95 #if !defined (FETCH_INFERIOR_REGISTERS)
96 #include <sys/user.h> /* Probably need to poke the user structure */
97 #if defined (KERNEL_U_ADDR_BSD)
98 #include <a.out.h> /* For struct nlist */
99 #endif /* KERNEL_U_ADDR_BSD. */
100 #endif /* !FETCH_INFERIOR_REGISTERS */
102 #if !defined (CHILD_XFER_MEMORY)
103 static void udot_info
PARAMS ((char *, int));
106 #if !defined (FETCH_INFERIOR_REGISTERS)
107 static void fetch_register
PARAMS ((int));
108 static void store_register
PARAMS ((int));
112 * Some systems (Linux) may have threads implemented as pseudo-processes,
113 * in which case we may be tracing more than one process at a time.
114 * In that case, inferior_pid will contain the main process ID and the
115 * individual thread (process) id mashed together. These macros are
116 * used to separate them out. The definitions may be overridden in tm.h
118 * NOTE: default definitions here are for systems with no threads.
119 * Useful definitions MUST be provided in tm.h
122 #if !defined (PIDGET) /* Default definition for PIDGET/TIDGET. */
123 #define PIDGET(PID) PID
124 #define TIDGET(PID) 0
127 void _initialize_kernel_u_addr
PARAMS ((void));
128 void _initialize_infptrace
PARAMS ((void));
131 /* This function simply calls ptrace with the given arguments.
132 It exists so that all calls to ptrace are isolated in this
133 machine-dependent file. */
135 call_ptrace (request
, pid
, addr
, data
)
137 PTRACE_ARG3_TYPE addr
;
145 printf ("call_ptrace(request=%d, pid=%d, addr=0x%x, data=0x%x)",
146 request
, pid
, addr
, data
);
148 #if defined(PT_SETTRC)
149 /* If the parent can be told to attach to us, try to do it. */
150 if (request
== PT_SETTRC
)
153 #if !defined (FIVE_ARG_PTRACE)
154 pt_status
= ptrace (PT_SETTRC
, pid
, addr
, data
);
156 /* Deal with HPUX 8.0 braindamage. We never use the
157 calls which require the fifth argument. */
158 pt_status
= ptrace (PT_SETTRC
, pid
, addr
, data
, 0);
161 perror_with_name ("ptrace");
163 printf (" = %d\n", pt_status
);
168 return parent_attach_all (pid
, addr
, data
);
172 #if defined(PT_CONTIN1)
173 /* On HPUX, PT_CONTIN1 is a form of continue that preserves pending
174 signals. If it's available, use it. */
175 if (request
== PT_CONTINUE
)
176 request
= PT_CONTIN1
;
179 #if defined(PT_SINGLE1)
180 /* On HPUX, PT_SINGLE1 is a form of step that preserves pending
181 signals. If it's available, use it. */
182 if (request
== PT_STEP
)
183 request
= PT_SINGLE1
;
190 #if !defined (FIVE_ARG_PTRACE)
191 pt_status
= ptrace (request
, pid
, addr
, data
);
193 /* Deal with HPUX 8.0 braindamage. We never use the
194 calls which require the fifth argument. */
195 pt_status
= ptrace (request
, pid
, addr
, data
, 0);
200 printf (" [errno = %d]", errno
);
203 printf (" = 0x%x\n", pt_status
);
209 #if defined (DEBUG_PTRACE) || defined (FIVE_ARG_PTRACE)
210 /* For the rest of the file, use an extra level of indirection */
211 /* This lets us breakpoint usefully on call_ptrace. */
212 #define ptrace call_ptrace
215 /* Wait for a process to finish, possibly running a target-specific
216 hook before returning. */
219 ptrace_wait (pid
, status
)
225 wstate
= wait (status
);
226 target_post_wait (wstate
, *status
);
235 if (inferior_pid
== 0)
238 /* This once used to call "kill" to kill the inferior just in case
239 the inferior was still running. As others have noted in the past
240 (kingdon) there shouldn't be any way to get here if the inferior
241 is still running -- else there's a major problem elsewere in gdb
242 and it needs to be fixed.
244 The kill call causes problems under hpux10, so it's been removed;
245 if this causes problems we'll deal with them as they arise. */
246 ptrace (PT_KILL
, inferior_pid
, (PTRACE_ARG3_TYPE
) 0, 0);
247 ptrace_wait (0, &status
);
248 target_mourn_inferior ();
253 /* Resume execution of the inferior process.
254 If STEP is nonzero, single-step it.
255 If SIGNAL is nonzero, give it that signal. */
258 child_resume (pid
, step
, signal
)
261 enum target_signal signal
;
266 /* Resume all threads. */
267 /* I think this only gets used in the non-threaded case, where "resume
268 all threads" and "resume inferior_pid" are the same. */
271 /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where
272 it was. (If GDB wanted it to start some other way, we have already
273 written a new PC value to the child.)
275 If this system does not support PT_STEP, a higher level function will
276 have called single_step() to transmute the step request into a
277 continue request (by setting breakpoints on all possible successor
278 instructions), so we don't have to worry about that here. */
282 if (SOFTWARE_SINGLE_STEP_P
)
283 abort (); /* Make sure this doesn't happen. */
285 ptrace (PT_STEP
, pid
, (PTRACE_ARG3_TYPE
) 1,
286 target_signal_to_host (signal
));
289 ptrace (PT_CONTINUE
, pid
, (PTRACE_ARG3_TYPE
) 1,
290 target_signal_to_host (signal
));
294 perror_with_name ("ptrace");
297 #endif /* CHILD_RESUME */
301 /* Start debugging the process whose number is PID. */
307 ptrace (PT_ATTACH
, pid
, (PTRACE_ARG3_TYPE
) 0, 0);
309 perror_with_name ("ptrace");
314 /* Stop debugging the process whose number is PID
315 and continue it with signal number SIGNAL.
316 SIGNAL = 0 means just continue it. */
323 ptrace (PT_DETACH
, inferior_pid
, (PTRACE_ARG3_TYPE
) 1, signal
);
325 perror_with_name ("ptrace");
328 #endif /* ATTACH_DETACH */
330 /* Default the type of the ptrace transfer to int. */
331 #ifndef PTRACE_XFER_TYPE
332 #define PTRACE_XFER_TYPE int
335 /* KERNEL_U_ADDR is the amount to subtract from u.u_ar0
336 to get the offset in the core file of the register values. */
337 #if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)
338 /* Get kernel_u_addr using BSD-style nlist(). */
339 CORE_ADDR kernel_u_addr
;
340 #endif /* KERNEL_U_ADDR_BSD. */
343 _initialize_kernel_u_addr ()
345 #if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)
346 struct nlist names
[2];
348 names
[0].n_un
.n_name
= "_u";
349 names
[1].n_un
.n_name
= NULL
;
350 if (nlist ("/vmunix", names
) == 0)
351 kernel_u_addr
= names
[0].n_value
;
353 internal_error ("Unable to get kernel u area address.");
354 #endif /* KERNEL_U_ADDR_BSD. */
357 #if !defined (FETCH_INFERIOR_REGISTERS)
359 #if !defined (offsetof)
360 #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
363 /* U_REGS_OFFSET is the offset of the registers within the u area. */
364 #if !defined (U_REGS_OFFSET)
365 #define U_REGS_OFFSET \
366 ptrace (PT_READ_U, inferior_pid, \
367 (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \
371 /* Registers we shouldn't try to fetch. */
372 #if !defined (CANNOT_FETCH_REGISTER)
373 #define CANNOT_FETCH_REGISTER(regno) 0
376 /* Fetch one register. */
379 fetch_register (regno
)
382 /* This isn't really an address. But ptrace thinks of it as one. */
384 char mess
[128]; /* For messages */
386 unsigned int offset
; /* Offset of registers within the u area. */
387 char buf
[MAX_REGISTER_RAW_SIZE
];
390 if (CANNOT_FETCH_REGISTER (regno
))
392 memset (buf
, '\0', REGISTER_RAW_SIZE (regno
)); /* Supply zeroes */
393 supply_register (regno
, buf
);
397 /* Overload thread id onto process id */
398 if ((tid
= TIDGET (inferior_pid
)) == 0)
399 tid
= inferior_pid
; /* no thread id, just use process id */
401 offset
= U_REGS_OFFSET
;
403 regaddr
= register_addr (regno
, offset
);
404 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof (PTRACE_XFER_TYPE
))
407 *(PTRACE_XFER_TYPE
*) & buf
[i
] = ptrace (PT_READ_U
, tid
,
408 (PTRACE_ARG3_TYPE
) regaddr
, 0);
409 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
412 sprintf (mess
, "reading register %s (#%d)",
413 REGISTER_NAME (regno
), regno
);
414 perror_with_name (mess
);
417 supply_register (regno
, buf
);
421 /* Fetch register values from the inferior.
422 If REGNO is negative, do this for all registers.
423 Otherwise, REGNO specifies which register (so we can save time). */
426 fetch_inferior_registers (regno
)
431 fetch_register (regno
);
435 for (regno
= 0; regno
< ARCH_NUM_REGS
; regno
++)
437 fetch_register (regno
);
442 /* Registers we shouldn't try to store. */
443 #if !defined (CANNOT_STORE_REGISTER)
444 #define CANNOT_STORE_REGISTER(regno) 0
447 /* Store one register. */
450 store_register (regno
)
453 /* This isn't really an address. But ptrace thinks of it as one. */
455 char mess
[128]; /* For messages */
457 unsigned int offset
; /* Offset of registers within the u area. */
460 if (CANNOT_STORE_REGISTER (regno
))
465 /* Overload thread id onto process id */
466 if ((tid
= TIDGET (inferior_pid
)) == 0)
467 tid
= inferior_pid
; /* no thread id, just use process id */
469 offset
= U_REGS_OFFSET
;
471 regaddr
= register_addr (regno
, offset
);
472 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof (PTRACE_XFER_TYPE
))
475 ptrace (PT_WRITE_U
, tid
, (PTRACE_ARG3_TYPE
) regaddr
,
476 *(PTRACE_XFER_TYPE
*) & registers
[REGISTER_BYTE (regno
) + i
]);
477 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
480 sprintf (mess
, "writing register %s (#%d)",
481 REGISTER_NAME (regno
), regno
);
482 perror_with_name (mess
);
487 /* Store our register values back into the inferior.
488 If REGNO is negative, do this for all registers.
489 Otherwise, REGNO specifies which register (so we can save time). */
492 store_inferior_registers (regno
)
497 store_register (regno
);
501 for (regno
= 0; regno
< ARCH_NUM_REGS
; regno
++)
503 store_register (regno
);
507 #endif /* !defined (FETCH_INFERIOR_REGISTERS). */
510 #if !defined (CHILD_XFER_MEMORY)
511 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
512 in the NEW_SUN_PTRACE case.
513 It ought to be straightforward. But it appears that writing did
514 not write the data that I specified. I cannot understand where
515 it got the data that it actually did write. */
517 /* Copy LEN bytes to or from inferior's memory starting at MEMADDR
518 to debugger memory starting at MYADDR. Copy to inferior if
521 Returns the length copied, which is either the LEN argument or zero.
522 This xfer function does not do partial moves, since child_ops
523 doesn't allow memory operations to cross below us in the target stack
527 child_xfer_memory (memaddr
, myaddr
, len
, write
, target
)
532 struct target_ops
*target
; /* ignored */
535 /* Round starting address down to longword boundary. */
536 register CORE_ADDR addr
= memaddr
& -sizeof (PTRACE_XFER_TYPE
);
537 /* Round ending address up; get number of longwords that makes. */
539 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
540 / sizeof (PTRACE_XFER_TYPE
);
541 /* Allocate buffer of that many longwords. */
542 register PTRACE_XFER_TYPE
*buffer
543 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
547 /* Fill start and end extra bytes of buffer with existing memory data. */
549 if (addr
!= memaddr
|| len
< (int) sizeof (PTRACE_XFER_TYPE
))
551 /* Need part of initial word -- fetch it. */
552 buffer
[0] = ptrace (PT_READ_I
, PIDGET (inferior_pid
),
553 (PTRACE_ARG3_TYPE
) addr
, 0);
556 if (count
> 1) /* FIXME, avoid if even boundary */
559 = ptrace (PT_READ_I
, PIDGET (inferior_pid
),
561 (addr
+ (count
- 1) * sizeof (PTRACE_XFER_TYPE
))),
565 /* Copy data to be written over corresponding part of buffer */
567 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
571 /* Write the entire buffer. */
573 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
576 ptrace (PT_WRITE_D
, PIDGET (inferior_pid
),
577 (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
580 /* Using the appropriate one (I or D) is necessary for
581 Gould NP1, at least. */
583 ptrace (PT_WRITE_I
, PIDGET (inferior_pid
),
584 (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
589 #ifdef CLEAR_INSN_CACHE
595 /* Read all the longwords */
596 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
599 buffer
[i
] = ptrace (PT_READ_I
, PIDGET (inferior_pid
),
600 (PTRACE_ARG3_TYPE
) addr
, 0);
606 /* Copy appropriate bytes out of the buffer. */
608 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
616 udot_info (dummy1
, dummy2
)
620 #if defined (KERNEL_U_SIZE)
621 int udot_off
; /* Offset into user struct */
622 int udot_val
; /* Value from user struct at udot_off */
623 char mess
[128]; /* For messages */
626 if (!target_has_execution
)
628 error ("The program is not being run.");
631 #if !defined (KERNEL_U_SIZE)
633 /* Adding support for this command is easy. Typically you just add a
634 routine, called "kernel_u_size" that returns the size of the user
635 struct, to the appropriate *-nat.c file and then add to the native
636 config file "#define KERNEL_U_SIZE kernel_u_size()" */
637 error ("Don't know how large ``struct user'' is in this version of gdb.");
641 for (udot_off
= 0; udot_off
< KERNEL_U_SIZE
; udot_off
+= sizeof (udot_val
))
643 if ((udot_off
% 24) == 0)
647 printf_filtered ("\n");
649 printf_filtered ("%04x:", udot_off
);
651 udot_val
= ptrace (PT_READ_U
, inferior_pid
, (PTRACE_ARG3_TYPE
) udot_off
, 0);
654 sprintf (mess
, "\nreading user struct at offset 0x%x", udot_off
);
655 perror_with_name (mess
);
657 /* Avoid using nonportable (?) "*" in print specs */
658 printf_filtered (sizeof (int) == 4 ? " 0x%08x" : " 0x%16x", udot_val
);
660 printf_filtered ("\n");
664 #endif /* !defined (CHILD_XFER_MEMORY). */
668 _initialize_infptrace ()
670 #if !defined (CHILD_XFER_MEMORY)
671 add_info ("udot", udot_info
,
672 "Print contents of kernel ``struct user'' for current child.");