453 lines
12 KiB
C
453 lines
12 KiB
C
/* Low level Unix child interface to ptrace, for GDB when running under Unix.
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Copyright 1988, 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include "defs.h"
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#include "frame.h"
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#include "inferior.h"
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#include "target.h"
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#ifdef USG
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#include <sys/types.h>
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#endif
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#include <sys/param.h>
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#include <sys/dir.h>
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#include <signal.h>
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#include <sys/ioctl.h>
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#ifndef NO_PTRACE_H
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#ifdef PTRACE_IN_WRONG_PLACE
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#include <ptrace.h>
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#else
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#include <sys/ptrace.h>
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#endif
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#endif /* NO_PTRACE_H */
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#if !defined (PT_KILL)
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#define PT_KILL 8
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#endif
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#if !defined (PT_STEP)
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#define PT_STEP 9
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#define PT_CONTINUE 7
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#define PT_READ_U 3
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#define PT_WRITE_U 6
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#define PT_READ_I 1
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#define PT_READ_D 2
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#define PT_WRITE_I 4
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#define PT_WRITE_D 5
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#endif /* No PT_STEP. */
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#ifndef PT_ATTACH
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#define PT_ATTACH PTRACE_ATTACH
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#endif
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#ifndef PT_DETACH
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#define PT_DETACH PTRACE_DETACH
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#endif
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#include "gdbcore.h"
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#ifndef NO_SYS_FILE
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#include <sys/file.h>
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#endif
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#if 0
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/* Don't think this is used anymore. On the sequent (not sure whether it's
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dynix or ptx or both), it is included unconditionally by sys/user.h and
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not protected against multiple inclusion. */
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#include <sys/stat.h>
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#endif
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#if !defined (FETCH_INFERIOR_REGISTERS)
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#include <sys/user.h> /* Probably need to poke the user structure */
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#if defined (KERNEL_U_ADDR_BSD)
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#include <a.out.h> /* For struct nlist */
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#endif /* KERNEL_U_ADDR_BSD. */
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#endif /* !FETCH_INFERIOR_REGISTERS */
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/* This function simply calls ptrace with the given arguments.
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It exists so that all calls to ptrace are isolated in this
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machine-dependent file. */
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int
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call_ptrace (request, pid, addr, data)
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int request, pid;
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PTRACE_ARG3_TYPE addr;
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int data;
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{
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return ptrace (request, pid, addr, data
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#if defined (FIVE_ARG_PTRACE)
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/* Deal with HPUX 8.0 braindamage. We never use the
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calls which require the fifth argument. */
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, 0
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#endif
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);
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}
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#if defined (DEBUG_PTRACE) || defined (FIVE_ARG_PTRACE)
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/* For the rest of the file, use an extra level of indirection */
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/* This lets us breakpoint usefully on call_ptrace. */
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#define ptrace call_ptrace
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#endif
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void
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kill_inferior ()
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{
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if (inferior_pid == 0)
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return;
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/* ptrace PT_KILL only works if process is stopped!!! So stop it with
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a real signal first, if we can. */
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kill (inferior_pid, SIGKILL);
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ptrace (PT_KILL, inferior_pid, (PTRACE_ARG3_TYPE) 0, 0);
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wait ((int *)0);
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target_mourn_inferior ();
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}
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/* Resume execution of the inferior process.
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If STEP is nonzero, single-step it.
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If SIGNAL is nonzero, give it that signal. */
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void
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child_resume (pid, step, signal)
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int pid;
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int step;
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enum target_signal signal;
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{
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errno = 0;
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if (pid == -1)
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/* Resume all threads. */
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#ifdef PIDGET
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/* This is for Lynx, and should be cleaned up by having Lynx be
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a separate debugging target, with its own target_resume function. */
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pid = PIDGET (inferior_pid);
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#else
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/* I think this only gets used in the non-threaded case, where "resume
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all threads" and "resume inferior_pid" are the same. */
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pid = inferior_pid;
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#endif
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/* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where
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it was. (If GDB wanted it to start some other way, we have already
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written a new PC value to the child.)
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If this system does not support PT_STEP, a higher level function will
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have called single_step() to transmute the step request into a
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continue request (by setting breakpoints on all possible successor
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instructions), so we don't have to worry about that here. */
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if (step)
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ptrace (PT_STEP, pid, (PTRACE_ARG3_TYPE) 1,
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target_signal_to_host (signal));
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else
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ptrace (PT_CONTINUE, pid, (PTRACE_ARG3_TYPE) 1,
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target_signal_to_host (signal));
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if (errno)
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perror_with_name ("ptrace");
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}
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#ifdef ATTACH_DETACH
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/* Start debugging the process whose number is PID. */
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int
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attach (pid)
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int pid;
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{
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errno = 0;
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ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 0, 0);
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if (errno)
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perror_with_name ("ptrace");
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attach_flag = 1;
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return pid;
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}
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/* Stop debugging the process whose number is PID
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and continue it with signal number SIGNAL.
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SIGNAL = 0 means just continue it. */
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void
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detach (signal)
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int signal;
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{
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errno = 0;
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ptrace (PT_DETACH, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal);
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if (errno)
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perror_with_name ("ptrace");
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attach_flag = 0;
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}
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#endif /* ATTACH_DETACH */
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/* Default the type of the ptrace transfer to int. */
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#ifndef PTRACE_XFER_TYPE
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#define PTRACE_XFER_TYPE int
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#endif
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/* KERNEL_U_ADDR is the amount to subtract from u.u_ar0
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to get the offset in the core file of the register values. */
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#if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)
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/* Get kernel_u_addr using BSD-style nlist(). */
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CORE_ADDR kernel_u_addr;
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#endif /* KERNEL_U_ADDR_BSD. */
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void
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_initialize_kernel_u_addr ()
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{
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#if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)
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struct nlist names[2];
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names[0].n_un.n_name = "_u";
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names[1].n_un.n_name = NULL;
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if (nlist ("/vmunix", names) == 0)
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kernel_u_addr = names[0].n_value;
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else
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fatal ("Unable to get kernel u area address.");
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#endif /* KERNEL_U_ADDR_BSD. */
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}
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#if !defined (FETCH_INFERIOR_REGISTERS)
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#if !defined (offsetof)
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#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
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#endif
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/* U_REGS_OFFSET is the offset of the registers within the u area. */
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#if !defined (U_REGS_OFFSET)
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#define U_REGS_OFFSET \
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ptrace (PT_READ_U, inferior_pid, \
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(PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \
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- KERNEL_U_ADDR
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#endif
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/* Registers we shouldn't try to fetch. */
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#if !defined (CANNOT_FETCH_REGISTER)
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#define CANNOT_FETCH_REGISTER(regno) 0
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#endif
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/* Fetch one register. */
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static void
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fetch_register (regno)
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int regno;
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{
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register unsigned int regaddr;
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char buf[MAX_REGISTER_RAW_SIZE];
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char mess[128]; /* For messages */
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register int i;
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/* Offset of registers within the u area. */
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unsigned int offset;
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if (CANNOT_FETCH_REGISTER (regno))
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{
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memset (buf, '\0', REGISTER_RAW_SIZE (regno)); /* Supply zeroes */
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supply_register (regno, buf);
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return;
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}
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offset = U_REGS_OFFSET;
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regaddr = register_addr (regno, offset);
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for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE))
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{
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errno = 0;
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*(PTRACE_XFER_TYPE *) &buf[i] = ptrace (PT_READ_U, inferior_pid,
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(PTRACE_ARG3_TYPE) regaddr, 0);
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regaddr += sizeof (PTRACE_XFER_TYPE);
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if (errno != 0)
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{
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sprintf (mess, "reading register %s (#%d)", reg_names[regno], regno);
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perror_with_name (mess);
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}
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}
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supply_register (regno, buf);
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}
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/* Fetch all registers, or just one, from the child process. */
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void
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fetch_inferior_registers (regno)
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int regno;
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{
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if (regno == -1)
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for (regno = 0; regno < NUM_REGS; regno++)
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fetch_register (regno);
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else
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fetch_register (regno);
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}
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/* Registers we shouldn't try to store. */
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#if !defined (CANNOT_STORE_REGISTER)
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#define CANNOT_STORE_REGISTER(regno) 0
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#endif
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/* Store our register values back into the inferior.
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If REGNO is -1, do this for all registers.
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Otherwise, REGNO specifies which register (so we can save time). */
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void
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store_inferior_registers (regno)
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int regno;
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{
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register unsigned int regaddr;
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char buf[80];
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register int i;
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unsigned int offset = U_REGS_OFFSET;
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if (regno >= 0)
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{
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regaddr = register_addr (regno, offset);
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for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(PTRACE_XFER_TYPE))
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{
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errno = 0;
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ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
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*(PTRACE_XFER_TYPE *) ®isters[REGISTER_BYTE (regno) + i]);
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if (errno != 0)
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{
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sprintf (buf, "writing register number %d(%d)", regno, i);
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perror_with_name (buf);
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}
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regaddr += sizeof(PTRACE_XFER_TYPE);
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}
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}
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else
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{
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for (regno = 0; regno < NUM_REGS; regno++)
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{
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if (CANNOT_STORE_REGISTER (regno))
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continue;
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regaddr = register_addr (regno, offset);
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for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(PTRACE_XFER_TYPE))
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{
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errno = 0;
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ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
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*(PTRACE_XFER_TYPE *) ®isters[REGISTER_BYTE (regno) + i]);
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if (errno != 0)
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{
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sprintf (buf, "writing register number %d(%d)", regno, i);
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perror_with_name (buf);
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}
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regaddr += sizeof(PTRACE_XFER_TYPE);
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}
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}
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}
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}
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#endif /* !defined (FETCH_INFERIOR_REGISTERS). */
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#if !defined (CHILD_XFER_MEMORY)
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/* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
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in the NEW_SUN_PTRACE case.
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It ought to be straightforward. But it appears that writing did
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not write the data that I specified. I cannot understand where
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it got the data that it actually did write. */
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/* Copy LEN bytes to or from inferior's memory starting at MEMADDR
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to debugger memory starting at MYADDR. Copy to inferior if
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WRITE is nonzero.
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Returns the length copied, which is either the LEN argument or zero.
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This xfer function does not do partial moves, since child_ops
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doesn't allow memory operations to cross below us in the target stack
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anyway. */
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int
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child_xfer_memory (memaddr, myaddr, len, write, target)
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CORE_ADDR memaddr;
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char *myaddr;
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int len;
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int write;
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struct target_ops *target; /* ignored */
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{
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register int i;
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/* Round starting address down to longword boundary. */
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register CORE_ADDR addr = memaddr & - sizeof (PTRACE_XFER_TYPE);
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/* Round ending address up; get number of longwords that makes. */
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register int count
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= (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
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/ sizeof (PTRACE_XFER_TYPE);
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/* Allocate buffer of that many longwords. */
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register PTRACE_XFER_TYPE *buffer
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= (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
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if (write)
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{
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/* Fill start and end extra bytes of buffer with existing memory data. */
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if (addr != memaddr || len < (int) sizeof (PTRACE_XFER_TYPE)) {
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/* Need part of initial word -- fetch it. */
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buffer[0] = ptrace (PT_READ_I, inferior_pid, (PTRACE_ARG3_TYPE) addr,
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0);
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}
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if (count > 1) /* FIXME, avoid if even boundary */
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{
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buffer[count - 1]
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= ptrace (PT_READ_I, inferior_pid,
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((PTRACE_ARG3_TYPE)
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(addr + (count - 1) * sizeof (PTRACE_XFER_TYPE))),
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0);
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}
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/* Copy data to be written over corresponding part of buffer */
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memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
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myaddr,
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len);
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/* Write the entire buffer. */
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for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
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{
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errno = 0;
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ptrace (PT_WRITE_D, inferior_pid, (PTRACE_ARG3_TYPE) addr,
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buffer[i]);
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if (errno)
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{
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/* Using the appropriate one (I or D) is necessary for
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Gould NP1, at least. */
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errno = 0;
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ptrace (PT_WRITE_I, inferior_pid, (PTRACE_ARG3_TYPE) addr,
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buffer[i]);
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}
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if (errno)
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return 0;
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}
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}
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else
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{
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/* Read all the longwords */
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for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
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{
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errno = 0;
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buffer[i] = ptrace (PT_READ_I, inferior_pid,
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(PTRACE_ARG3_TYPE) addr, 0);
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if (errno)
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return 0;
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QUIT;
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}
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/* Copy appropriate bytes out of the buffer. */
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memcpy (myaddr,
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(char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
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len);
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}
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return len;
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}
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#endif /* !defined (CHILD_XFER_MEMORY). */
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