1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002
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. */
23 #include "linux-low.h"
27 #include <sys/param.h>
29 #include <sys/ptrace.h>
32 #include <sys/ioctl.h>
38 static CORE_ADDR linux_bp_reinsert
;
40 static void linux_resume (int step
, int signal
);
42 #define PTRACE_ARG3_TYPE long
43 #define PTRACE_XFER_TYPE long
45 #ifdef HAVE_LINUX_REGSETS
46 static int use_regsets_p
= 1;
51 static int inferior_pid
;
53 struct inferior_linux_data
58 /* Start an inferior process and returns its pid.
59 ALLARGS is a vector of program-name and args. */
62 linux_create_inferior (char *program
, char **allargs
)
64 struct inferior_linux_data
*tdata
;
69 perror_with_name ("fork");
73 ptrace (PTRACE_TRACEME
, 0, 0, 0);
75 execv (program
, allargs
);
77 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
84 tdata
= (struct inferior_linux_data
*) malloc (sizeof (*tdata
));
86 set_inferior_target_data (current_inferior
, tdata
);
93 /* Attach to an inferior process. */
96 linux_attach (int pid
)
98 struct inferior_linux_data
*tdata
;
100 if (ptrace (PTRACE_ATTACH
, pid
, 0, 0) != 0)
102 fprintf (stderr
, "Cannot attach to process %d: %s (%d)\n", pid
,
103 errno
< sys_nerr
? sys_errlist
[errno
] : "unknown error",
110 tdata
= (struct inferior_linux_data
*) malloc (sizeof (*tdata
));
112 set_inferior_target_data (current_inferior
, tdata
);
116 /* Kill the inferior process. Make us have no inferior. */
121 if (inferior_pid
== 0)
123 ptrace (PTRACE_KILL
, inferior_pid
, 0, 0);
128 /* Return nonzero if the given thread is still alive. */
130 linux_thread_alive (int pid
)
136 linux_wait_for_one_inferior (struct inferior_info
*child
)
138 struct inferior_linux_data
*child_data
= inferior_target_data (child
);
143 pid
= waitpid (child_data
->pid
, &wstat
, 0);
145 if (pid
!= child_data
->pid
)
146 perror_with_name ("wait");
148 /* If this target supports breakpoints, see if we hit one. */
149 if (the_low_target
.stop_pc
!= NULL
150 && WIFSTOPPED (wstat
)
151 && WSTOPSIG (wstat
) == SIGTRAP
)
155 if (linux_bp_reinsert
!= 0)
157 reinsert_breakpoint (linux_bp_reinsert
);
158 linux_bp_reinsert
= 0;
163 fetch_inferior_registers (0);
164 stop_pc
= (*the_low_target
.stop_pc
) ();
166 if (check_breakpoints (stop_pc
) != 0)
168 if (the_low_target
.set_pc
!= NULL
)
169 (*the_low_target
.set_pc
) (stop_pc
);
171 if (the_low_target
.breakpoint_reinsert_addr
== NULL
)
173 linux_bp_reinsert
= stop_pc
;
174 uninsert_breakpoint (stop_pc
);
179 reinsert_breakpoint_by_bp
180 (stop_pc
, (*the_low_target
.breakpoint_reinsert_addr
) ());
194 /* Wait for process, returns status */
197 linux_wait (char *status
)
202 w
= linux_wait_for_one_inferior (current_inferior
);
207 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
210 return ((unsigned char) WEXITSTATUS (w
));
212 else if (!WIFSTOPPED (w
))
214 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
217 return ((unsigned char) WTERMSIG (w
));
220 fetch_inferior_registers (0);
223 return ((unsigned char) WSTOPSIG (w
));
226 /* Resume execution of the inferior process.
227 If STEP is nonzero, single-step it.
228 If SIGNAL is nonzero, give it that signal. */
231 linux_resume (int step
, int signal
)
234 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, inferior_pid
, 1, signal
);
236 perror_with_name ("ptrace");
240 #ifdef HAVE_LINUX_USRREGS
242 #define REGISTER_RAW_SIZE(regno) register_size((regno))
245 register_addr (int regnum
)
249 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
250 error ("Invalid register number %d.", regnum
);
252 addr
= the_low_target
.regmap
[regnum
];
259 /* Fetch one register. */
261 fetch_register (int regno
)
266 if (regno
>= the_low_target
.num_regs
)
268 if ((*the_low_target
.cannot_fetch_register
) (regno
))
271 regaddr
= register_addr (regno
);
274 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof (PTRACE_XFER_TYPE
))
277 *(PTRACE_XFER_TYPE
*) (register_data (regno
) + i
) =
278 ptrace (PTRACE_PEEKUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
, 0);
279 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
282 /* Warning, not error, in case we are attached; sometimes the
283 kernel doesn't let us at the registers. */
284 char *err
= strerror (errno
);
285 char *msg
= alloca (strlen (err
) + 128);
286 sprintf (msg
, "reading register %d: %s", regno
, err
);
294 /* Fetch all registers, or just one, from the child process. */
296 usr_fetch_inferior_registers (int regno
)
298 if (regno
== -1 || regno
== 0)
299 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
300 fetch_register (regno
);
302 fetch_register (regno
);
305 /* Store our register values back into the inferior.
306 If REGNO is -1, do this for all registers.
307 Otherwise, REGNO specifies which register (so we can save time). */
309 usr_store_inferior_registers (int regno
)
316 if (regno
>= the_low_target
.num_regs
)
319 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
322 regaddr
= register_addr (regno
);
326 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
+= sizeof (PTRACE_XFER_TYPE
))
329 ptrace (PTRACE_POKEUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
,
330 *(int *) (register_data (regno
) + i
));
333 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
335 char *err
= strerror (errno
);
336 char *msg
= alloca (strlen (err
) + 128);
337 sprintf (msg
, "writing register %d: %s",
343 regaddr
+= sizeof (int);
347 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
348 store_inferior_registers (regno
);
350 #endif /* HAVE_LINUX_USRREGS */
354 #ifdef HAVE_LINUX_REGSETS
357 regsets_fetch_inferior_registers (void)
359 struct regset_info
*regset
;
361 regset
= target_regsets
;
363 while (regset
->size
>= 0)
368 if (regset
->size
== 0)
374 buf
= malloc (regset
->size
);
375 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
380 /* If we get EIO on the first regset, do not try regsets again.
381 If we get EIO on a later regset, disable that regset. */
382 if (regset
== target_regsets
)
395 perror ("Warning: ptrace(regsets_fetch_inferior_registers)");
398 regset
->store_function (buf
);
405 regsets_store_inferior_registers (void)
407 struct regset_info
*regset
;
409 regset
= target_regsets
;
411 while (regset
->size
>= 0)
416 if (regset
->size
== 0)
422 buf
= malloc (regset
->size
);
423 regset
->fill_function (buf
);
424 res
= ptrace (regset
->set_request
, inferior_pid
, 0, buf
);
429 /* If we get EIO on the first regset, do not try regsets again.
430 If we get EIO on a later regset, disable that regset. */
431 if (regset
== target_regsets
)
444 perror ("Warning: ptrace(regsets_store_inferior_registers)");
452 #endif /* HAVE_LINUX_REGSETS */
456 linux_fetch_registers (int regno
)
458 #ifdef HAVE_LINUX_REGSETS
461 if (regsets_fetch_inferior_registers () == 0)
465 #ifdef HAVE_LINUX_USRREGS
466 usr_fetch_inferior_registers (regno
);
471 linux_store_registers (int regno
)
473 #ifdef HAVE_LINUX_REGSETS
476 if (regsets_store_inferior_registers () == 0)
480 #ifdef HAVE_LINUX_USRREGS
481 usr_store_inferior_registers (regno
);
486 /* Copy LEN bytes from inferior's memory starting at MEMADDR
487 to debugger memory starting at MYADDR. */
490 linux_read_memory (CORE_ADDR memaddr
, char *myaddr
, int len
)
493 /* Round starting address down to longword boundary. */
494 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
495 /* Round ending address up; get number of longwords that makes. */
497 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
498 / sizeof (PTRACE_XFER_TYPE
);
499 /* Allocate buffer of that many longwords. */
500 register PTRACE_XFER_TYPE
*buffer
501 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
503 /* Read all the longwords */
504 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
506 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, 0);
509 /* Copy appropriate bytes out of the buffer. */
510 memcpy (myaddr
, (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), len
);
513 /* Copy LEN bytes of data from debugger memory at MYADDR
514 to inferior's memory at MEMADDR.
515 On failure (cannot write the inferior)
516 returns the value of errno. */
519 linux_write_memory (CORE_ADDR memaddr
, const char *myaddr
, int len
)
522 /* Round starting address down to longword boundary. */
523 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
524 /* Round ending address up; get number of longwords that makes. */
526 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
527 /* Allocate buffer of that many longwords. */
528 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
531 /* Fill start and end extra bytes of buffer with existing memory data. */
533 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
534 (PTRACE_ARG3_TYPE
) addr
, 0);
539 = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
540 (PTRACE_ARG3_TYPE
) (addr
+ (count
- 1)
541 * sizeof (PTRACE_XFER_TYPE
)),
545 /* Copy data to be written over corresponding part of buffer */
547 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
549 /* Write the entire buffer. */
551 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
554 ptrace (PTRACE_POKETEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
563 linux_look_up_symbols (void)
565 /* Don't need to look up any symbols yet. */
569 static struct target_ops linux_target_ops
= {
570 linux_create_inferior
,
576 linux_fetch_registers
,
577 linux_store_registers
,
580 linux_look_up_symbols
,
584 initialize_low (void)
586 set_target_ops (&linux_target_ops
);
587 set_breakpoint_data (the_low_target
.breakpoint
,
588 the_low_target
.breakpoint_len
);