1 /* Low level Unix child interface to ptrace, for GDB when running under Unix.
2 Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
3 1998, 1999, 2000, 2001, 2002
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
27 #include "gdb_string.h"
35 #include <sys/types.h>
38 #include <sys/param.h>
39 #include "gdb_dirent.h"
41 #include <sys/ioctl.h>
46 #ifdef HAVE_SYS_PTRACE_H
47 #include <sys/ptrace.h>
51 #if !defined (PT_READ_I)
52 #define PT_READ_I 1 /* Read word from text space */
54 #if !defined (PT_READ_D)
55 #define PT_READ_D 2 /* Read word from data space */
57 #if !defined (PT_READ_U)
58 #define PT_READ_U 3 /* Read word from kernel user struct */
60 #if !defined (PT_WRITE_I)
61 #define PT_WRITE_I 4 /* Write word to text space */
63 #if !defined (PT_WRITE_D)
64 #define PT_WRITE_D 5 /* Write word to data space */
66 #if !defined (PT_WRITE_U)
67 #define PT_WRITE_U 6 /* Write word to kernel user struct */
69 #if !defined (PT_CONTINUE)
70 #define PT_CONTINUE 7 /* Continue after signal */
72 #if !defined (PT_STEP)
73 #define PT_STEP 9 /* Set flag for single stepping */
75 #if !defined (PT_KILL)
76 #define PT_KILL 8 /* Send child a SIGKILL signal */
84 /* Don't think this is used anymore. On the sequent (not sure whether it's
85 dynix or ptx or both), it is included unconditionally by sys/user.h and
86 not protected against multiple inclusion. */
90 #if !defined (FETCH_INFERIOR_REGISTERS)
91 #include <sys/user.h> /* Probably need to poke the user structure */
92 #if defined (KERNEL_U_ADDR_BSD)
93 #include <a.out.h> /* For struct nlist */
94 #endif /* KERNEL_U_ADDR_BSD. */
95 #endif /* !FETCH_INFERIOR_REGISTERS */
97 #if !defined (CHILD_XFER_MEMORY)
98 static void udot_info (char *, int);
101 #if !defined (FETCH_INFERIOR_REGISTERS)
102 static void fetch_register (int);
103 static void store_register (int);
106 void _initialize_kernel_u_addr (void);
107 void _initialize_infptrace (void);
110 /* This function simply calls ptrace with the given arguments.
111 It exists so that all calls to ptrace are isolated in this
112 machine-dependent file. */
114 call_ptrace (int request
, int pid
, PTRACE_ARG3_TYPE addr
, int data
)
121 printf ("call_ptrace(request=%d, pid=%d, addr=0x%x, data=0x%x)",
122 request
, pid
, addr
, data
);
124 #if defined(PT_SETTRC)
125 /* If the parent can be told to attach to us, try to do it. */
126 if (request
== PT_SETTRC
)
129 #if !defined (FIVE_ARG_PTRACE)
130 pt_status
= ptrace (PT_SETTRC
, pid
, addr
, data
);
132 /* Deal with HPUX 8.0 braindamage. We never use the
133 calls which require the fifth argument. */
134 pt_status
= ptrace (PT_SETTRC
, pid
, addr
, data
, 0);
137 perror_with_name ("ptrace");
139 printf (" = %d\n", pt_status
);
144 return parent_attach_all (pid
, addr
, data
);
148 #if defined(PT_CONTIN1)
149 /* On HPUX, PT_CONTIN1 is a form of continue that preserves pending
150 signals. If it's available, use it. */
151 if (request
== PT_CONTINUE
)
152 request
= PT_CONTIN1
;
155 #if defined(PT_SINGLE1)
156 /* On HPUX, PT_SINGLE1 is a form of step that preserves pending
157 signals. If it's available, use it. */
158 if (request
== PT_STEP
)
159 request
= PT_SINGLE1
;
166 #if !defined (FIVE_ARG_PTRACE)
167 pt_status
= ptrace (request
, pid
, addr
, data
);
169 /* Deal with HPUX 8.0 braindamage. We never use the
170 calls which require the fifth argument. */
171 pt_status
= ptrace (request
, pid
, addr
, data
, 0);
176 printf (" [errno = %d]", errno
);
179 printf (" = 0x%x\n", pt_status
);
185 #if defined (DEBUG_PTRACE) || defined (FIVE_ARG_PTRACE)
186 /* For the rest of the file, use an extra level of indirection */
187 /* This lets us breakpoint usefully on call_ptrace. */
188 #define ptrace call_ptrace
191 /* Wait for a process to finish, possibly running a target-specific
192 hook before returning. */
195 ptrace_wait (ptid_t ptid
, int *status
)
199 wstate
= wait (status
);
200 target_post_wait (pid_to_ptid (wstate
), *status
);
204 #ifndef KILL_INFERIOR
209 int pid
= PIDGET (inferior_ptid
);
214 /* This once used to call "kill" to kill the inferior just in case
215 the inferior was still running. As others have noted in the past
216 (kingdon) there shouldn't be any way to get here if the inferior
217 is still running -- else there's a major problem elsewere in gdb
218 and it needs to be fixed.
220 The kill call causes problems under hpux10, so it's been removed;
221 if this causes problems we'll deal with them as they arise. */
222 ptrace (PT_KILL
, pid
, (PTRACE_ARG3_TYPE
) 0, 0);
223 ptrace_wait (null_ptid
, &status
);
224 target_mourn_inferior ();
226 #endif /* KILL_INFERIOR */
230 /* Resume execution of the inferior process.
231 If STEP is nonzero, single-step it.
232 If SIGNAL is nonzero, give it that signal. */
235 child_resume (ptid_t ptid
, int step
, enum target_signal signal
)
237 int pid
= PIDGET (ptid
);
242 /* Resume all threads. */
243 /* I think this only gets used in the non-threaded case, where "resume
244 all threads" and "resume inferior_ptid" are the same. */
245 pid
= PIDGET (inferior_ptid
);
247 /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where
248 it was. (If GDB wanted it to start some other way, we have already
249 written a new PC value to the child.)
251 If this system does not support PT_STEP, a higher level function will
252 have called single_step() to transmute the step request into a
253 continue request (by setting breakpoints on all possible successor
254 instructions), so we don't have to worry about that here. */
258 if (SOFTWARE_SINGLE_STEP_P ())
259 internal_error (__FILE__
, __LINE__
, "failed internal consistency check"); /* Make sure this doesn't happen. */
261 ptrace (PT_STEP
, pid
, (PTRACE_ARG3_TYPE
) 1,
262 target_signal_to_host (signal
));
265 ptrace (PT_CONTINUE
, pid
, (PTRACE_ARG3_TYPE
) 1,
266 target_signal_to_host (signal
));
270 perror_with_name ("ptrace");
273 #endif /* CHILD_RESUME */
275 /* Start debugging the process whose number is PID. */
282 #define PT_ATTACH PTRACE_ATTACH
286 ptrace (PT_ATTACH
, pid
, (PTRACE_ARG3_TYPE
) 0, 0);
288 perror_with_name ("ptrace");
292 error ("This system does not support attaching to a process");
296 /* Stop debugging the process whose number is PID
297 and continue it with signal number SIGNAL.
298 SIGNAL = 0 means just continue it. */
306 #define PT_DETACH PTRACE_DETACH
310 ptrace (PT_DETACH
, PIDGET (inferior_ptid
), (PTRACE_ARG3_TYPE
) 1,
313 print_sys_errmsg ("ptrace", errno
);
316 error ("This system does not support detaching from a process");
320 /* Default the type of the ptrace transfer to int. */
321 #ifndef PTRACE_XFER_TYPE
322 #define PTRACE_XFER_TYPE int
325 /* KERNEL_U_ADDR is the amount to subtract from u.u_ar0
326 to get the offset in the core file of the register values. */
327 #if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)
328 /* Get kernel_u_addr using BSD-style nlist(). */
329 CORE_ADDR kernel_u_addr
;
330 #endif /* KERNEL_U_ADDR_BSD. */
333 _initialize_kernel_u_addr (void)
335 #if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)
336 struct nlist names
[2];
338 names
[0].n_un
.n_name
= "_u";
339 names
[1].n_un
.n_name
= NULL
;
340 if (nlist ("/vmunix", names
) == 0)
341 kernel_u_addr
= names
[0].n_value
;
343 internal_error (__FILE__
, __LINE__
,
344 "Unable to get kernel u area address.");
345 #endif /* KERNEL_U_ADDR_BSD. */
348 #if !defined (FETCH_INFERIOR_REGISTERS)
350 #if !defined (offsetof)
351 #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
354 /* U_REGS_OFFSET is the offset of the registers within the u area. */
355 #if !defined (U_REGS_OFFSET)
356 #define U_REGS_OFFSET \
357 ptrace (PT_READ_U, PIDGET (inferior_ptid), \
358 (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \
362 /* Fetch one register. */
365 fetch_register (int regno
)
367 /* This isn't really an address. But ptrace thinks of it as one. */
369 char mess
[128]; /* For messages */
371 unsigned int offset
; /* Offset of registers within the u area. */
372 char buf
[MAX_REGISTER_SIZE
];
375 if (CANNOT_FETCH_REGISTER (regno
))
377 memset (buf
, '\0', DEPRECATED_REGISTER_RAW_SIZE (regno
)); /* Supply zeroes */
378 supply_register (regno
, buf
);
382 /* Overload thread id onto process id */
383 if ((tid
= TIDGET (inferior_ptid
)) == 0)
384 tid
= PIDGET (inferior_ptid
); /* no thread id, just use process id */
386 offset
= U_REGS_OFFSET
;
388 regaddr
= register_addr (regno
, offset
);
389 for (i
= 0; i
< DEPRECATED_REGISTER_RAW_SIZE (regno
); i
+= sizeof (PTRACE_XFER_TYPE
))
392 *(PTRACE_XFER_TYPE
*) & buf
[i
] = ptrace (PT_READ_U
, tid
,
393 (PTRACE_ARG3_TYPE
) regaddr
, 0);
394 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
397 sprintf (mess
, "reading register %s (#%d)",
398 REGISTER_NAME (regno
), regno
);
399 perror_with_name (mess
);
402 supply_register (regno
, buf
);
406 /* Fetch register values from the inferior.
407 If REGNO is negative, do this for all registers.
408 Otherwise, REGNO specifies which register (so we can save time). */
411 fetch_inferior_registers (int regno
)
415 fetch_register (regno
);
419 for (regno
= 0; regno
< NUM_REGS
; regno
++)
421 fetch_register (regno
);
426 /* Store one register. */
429 store_register (int regno
)
431 /* This isn't really an address. But ptrace thinks of it as one. */
433 char mess
[128]; /* For messages */
435 unsigned int offset
; /* Offset of registers within the u area. */
437 char buf
[MAX_REGISTER_SIZE
];
439 if (CANNOT_STORE_REGISTER (regno
))
444 /* Overload thread id onto process id */
445 if ((tid
= TIDGET (inferior_ptid
)) == 0)
446 tid
= PIDGET (inferior_ptid
); /* no thread id, just use process id */
448 offset
= U_REGS_OFFSET
;
450 regaddr
= register_addr (regno
, offset
);
452 /* Put the contents of regno into a local buffer */
453 regcache_collect (regno
, buf
);
455 /* Store the local buffer into the inferior a chunk at the time. */
456 for (i
= 0; i
< DEPRECATED_REGISTER_RAW_SIZE (regno
); i
+= sizeof (PTRACE_XFER_TYPE
))
459 ptrace (PT_WRITE_U
, tid
, (PTRACE_ARG3_TYPE
) regaddr
,
460 *(PTRACE_XFER_TYPE
*) (buf
+ i
));
461 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
464 sprintf (mess
, "writing register %s (#%d)",
465 REGISTER_NAME (regno
), regno
);
466 perror_with_name (mess
);
471 /* Store our register values back into the inferior.
472 If REGNO is negative, do this for all registers.
473 Otherwise, REGNO specifies which register (so we can save time). */
476 store_inferior_registers (int regno
)
480 store_register (regno
);
484 for (regno
= 0; regno
< NUM_REGS
; regno
++)
486 store_register (regno
);
490 #endif /* !defined (FETCH_INFERIOR_REGISTERS). */
493 /* Set an upper limit on alloca. */
494 #ifndef GDB_MAX_ALLOCA
495 #define GDB_MAX_ALLOCA 0x1000
498 #if !defined (CHILD_XFER_MEMORY)
499 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
500 in the NEW_SUN_PTRACE case. It ought to be straightforward. But
501 it appears that writing did not write the data that I specified. I
502 cannot understand where it got the data that it actually did write. */
504 /* Copy LEN bytes to or from inferior's memory starting at MEMADDR to
505 debugger memory starting at MYADDR. Copy to inferior if WRITE is
506 nonzero. TARGET is ignored.
508 Returns the length copied, which is either the LEN argument or
509 zero. This xfer function does not do partial moves, since
510 child_ops doesn't allow memory operations to cross below us in the
511 target stack anyway. */
514 child_xfer_memory (CORE_ADDR memaddr
, char *myaddr
, int len
, int write
,
515 struct mem_attrib
*attrib
, struct target_ops
*target
)
518 /* Round starting address down to longword boundary. */
519 CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
520 /* Round ending address up; get number of longwords that makes. */
521 int count
= ((((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
522 / sizeof (PTRACE_XFER_TYPE
));
523 int alloc
= count
* sizeof (PTRACE_XFER_TYPE
);
524 PTRACE_XFER_TYPE
*buffer
;
525 struct cleanup
*old_chain
= NULL
;
528 /* OpenBSD 3.1, NetBSD 1.6 and FreeBSD 5.0 have a new PT_IO request
529 that promises to be much more efficient in reading and writing
530 data in the traced process's address space. */
533 struct ptrace_io_desc piod
;
535 /* NOTE: We assume that there are no distinct address spaces for
536 instruction and data. */
537 piod
.piod_op
= write
? PIOD_WRITE_D
: PIOD_READ_D
;
538 piod
.piod_offs
= (void *) memaddr
;
539 piod
.piod_addr
= myaddr
;
542 if (ptrace (PT_IO
, PIDGET (inferior_ptid
), (caddr_t
) &piod
, 0) == -1)
544 /* If the PT_IO request is somehow not supported, fallback on
545 using PT_WRITE_D/PT_READ_D. Otherwise we will return zero
546 to indicate failure. */
552 /* Return the actual number of bytes read or written. */
553 return piod
.piod_len
;
558 /* Allocate buffer of that many longwords. */
559 if (len
< GDB_MAX_ALLOCA
)
561 buffer
= (PTRACE_XFER_TYPE
*) alloca (alloc
);
565 buffer
= (PTRACE_XFER_TYPE
*) xmalloc (alloc
);
566 old_chain
= make_cleanup (xfree
, buffer
);
571 /* Fill start and end extra bytes of buffer with existing memory
573 if (addr
!= memaddr
|| len
< (int) sizeof (PTRACE_XFER_TYPE
))
575 /* Need part of initial word -- fetch it. */
576 buffer
[0] = ptrace (PT_READ_I
, PIDGET (inferior_ptid
),
577 (PTRACE_ARG3_TYPE
) addr
, 0);
580 if (count
> 1) /* FIXME, avoid if even boundary. */
583 ptrace (PT_READ_I
, PIDGET (inferior_ptid
),
585 (addr
+ (count
- 1) * sizeof (PTRACE_XFER_TYPE
))), 0);
588 /* Copy data to be written over corresponding part of buffer. */
589 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
592 /* Write the entire buffer. */
593 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
596 ptrace (PT_WRITE_D
, PIDGET (inferior_ptid
),
597 (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
600 /* Using the appropriate one (I or D) is necessary for
601 Gould NP1, at least. */
603 ptrace (PT_WRITE_I
, PIDGET (inferior_ptid
),
604 (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
612 /* Read all the longwords. */
613 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
616 buffer
[i
] = ptrace (PT_READ_I
, PIDGET (inferior_ptid
),
617 (PTRACE_ARG3_TYPE
) addr
, 0);
623 /* Copy appropriate bytes out of the buffer. */
625 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
629 if (old_chain
!= NULL
)
630 do_cleanups (old_chain
);
636 udot_info (char *dummy1
, int dummy2
)
638 #if defined (KERNEL_U_SIZE)
639 long udot_off
; /* Offset into user struct */
640 int udot_val
; /* Value from user struct at udot_off */
641 char mess
[128]; /* For messages */
644 if (!target_has_execution
)
646 error ("The program is not being run.");
649 #if !defined (KERNEL_U_SIZE)
651 /* Adding support for this command is easy. Typically you just add a
652 routine, called "kernel_u_size" that returns the size of the user
653 struct, to the appropriate *-nat.c file and then add to the native
654 config file "#define KERNEL_U_SIZE kernel_u_size()" */
655 error ("Don't know how large ``struct user'' is in this version of gdb.");
659 for (udot_off
= 0; udot_off
< KERNEL_U_SIZE
; udot_off
+= sizeof (udot_val
))
661 if ((udot_off
% 24) == 0)
665 printf_filtered ("\n");
667 printf_filtered ("%s:", paddr (udot_off
));
669 udot_val
= ptrace (PT_READ_U
, PIDGET (inferior_ptid
), (PTRACE_ARG3_TYPE
) udot_off
, 0);
672 sprintf (mess
, "\nreading user struct at offset 0x%s",
673 paddr_nz (udot_off
));
674 perror_with_name (mess
);
676 /* Avoid using nonportable (?) "*" in print specs */
677 printf_filtered (sizeof (int) == 4 ? " 0x%08x" : " 0x%16x", udot_val
);
679 printf_filtered ("\n");
683 #endif /* !defined (CHILD_XFER_MEMORY). */
687 _initialize_infptrace (void)
689 #if !defined (CHILD_XFER_MEMORY)
690 add_info ("udot", udot_info
,
691 "Print contents of kernel ``struct user'' for current child.");
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