09ec9b38d6
* linux-low.c (regsets_store_inferior_registers): Add free() at the end of a loop to prevent memory leak. * linux-x86-64-low.c (x86_64_regmap): Add CS, SS registers. (X86_64_NUM_GREGS): Count it from the size of x86_64_regmap.
1292 lines
35 KiB
C
1292 lines
35 KiB
C
/* Low level interface to ptrace, for the remote server for GDB.
|
||
Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002
|
||
Free Software Foundation, Inc.
|
||
|
||
This file is part of GDB.
|
||
|
||
This program is free software; you can redistribute it and/or modify
|
||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 2 of the License, or
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with this program; if not, write to the Free Software
|
||
Foundation, Inc., 59 Temple Place - Suite 330,
|
||
Boston, MA 02111-1307, USA. */
|
||
|
||
#include "server.h"
|
||
#include "linux-low.h"
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|
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#include <sys/wait.h>
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#include <stdio.h>
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||
#include <sys/param.h>
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||
#include <sys/dir.h>
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||
#include <sys/ptrace.h>
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||
#include <sys/user.h>
|
||
#include <signal.h>
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||
#include <sys/ioctl.h>
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||
#include <fcntl.h>
|
||
#include <string.h>
|
||
#include <stdlib.h>
|
||
#include <unistd.h>
|
||
|
||
/* ``all_threads'' is keyed by the LWP ID - it should be the thread ID instead,
|
||
however. This requires changing the ID in place when we go from !using_threads
|
||
to using_threads, immediately.
|
||
|
||
``all_processes'' is keyed by the process ID - which on Linux is (presently)
|
||
the same as the LWP ID. */
|
||
|
||
struct inferior_list all_processes;
|
||
|
||
/* FIXME this is a bit of a hack, and could be removed. */
|
||
int stopping_threads;
|
||
|
||
/* FIXME make into a target method? */
|
||
int using_threads;
|
||
|
||
static void linux_resume_one_process (struct inferior_list_entry *entry,
|
||
int step, int signal);
|
||
static void linux_resume (int step, int signal);
|
||
static void stop_all_processes (void);
|
||
static int linux_wait_for_event (struct thread_info *child);
|
||
|
||
struct pending_signals
|
||
{
|
||
int signal;
|
||
struct pending_signals *prev;
|
||
};
|
||
|
||
#define PTRACE_ARG3_TYPE long
|
||
#define PTRACE_XFER_TYPE long
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||
|
||
#ifdef HAVE_LINUX_REGSETS
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||
static int use_regsets_p = 1;
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||
#endif
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||
|
||
extern int errno;
|
||
|
||
int debug_threads = 0;
|
||
|
||
#define pid_of(proc) ((proc)->head.id)
|
||
|
||
/* FIXME: Delete eventually. */
|
||
#define inferior_pid (pid_of (get_thread_process (current_inferior)))
|
||
|
||
/* This function should only be called if the process got a SIGTRAP.
|
||
The SIGTRAP could mean several things.
|
||
|
||
On i386, where decr_pc_after_break is non-zero:
|
||
If we were single-stepping this process using PTRACE_SINGLESTEP,
|
||
we will get only the one SIGTRAP (even if the instruction we
|
||
stepped over was a breakpoint). The value of $eip will be the
|
||
next instruction.
|
||
If we continue the process using PTRACE_CONT, we will get a
|
||
SIGTRAP when we hit a breakpoint. The value of $eip will be
|
||
the instruction after the breakpoint (i.e. needs to be
|
||
decremented). If we report the SIGTRAP to GDB, we must also
|
||
report the undecremented PC. If we cancel the SIGTRAP, we
|
||
must resume at the decremented PC.
|
||
|
||
(Presumably, not yet tested) On a non-decr_pc_after_break machine
|
||
with hardware or kernel single-step:
|
||
If we single-step over a breakpoint instruction, our PC will
|
||
point at the following instruction. If we continue and hit a
|
||
breakpoint instruction, our PC will point at the breakpoint
|
||
instruction. */
|
||
|
||
static CORE_ADDR
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||
get_stop_pc (void)
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||
{
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||
CORE_ADDR stop_pc = (*the_low_target.get_pc) ();
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||
|
||
if (get_thread_process (current_inferior)->stepping)
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return stop_pc;
|
||
else
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||
return stop_pc - the_low_target.decr_pc_after_break;
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||
}
|
||
|
||
static void *
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||
add_process (int pid)
|
||
{
|
||
struct process_info *process;
|
||
|
||
process = (struct process_info *) malloc (sizeof (*process));
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||
memset (process, 0, sizeof (*process));
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||
|
||
process->head.id = pid;
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||
|
||
/* Default to tid == lwpid == pid. */
|
||
process->tid = pid;
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||
process->lwpid = pid;
|
||
|
||
add_inferior_to_list (&all_processes, &process->head);
|
||
|
||
return process;
|
||
}
|
||
|
||
/* Start an inferior process and returns its pid.
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||
ALLARGS is a vector of program-name and args. */
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||
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||
static int
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linux_create_inferior (char *program, char **allargs)
|
||
{
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||
void *new_process;
|
||
int pid;
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||
|
||
pid = fork ();
|
||
if (pid < 0)
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||
perror_with_name ("fork");
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||
|
||
if (pid == 0)
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||
{
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||
ptrace (PTRACE_TRACEME, 0, 0, 0);
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||
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||
signal (SIGRTMIN + 1, SIG_DFL);
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||
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||
execv (program, allargs);
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||
|
||
fprintf (stderr, "Cannot exec %s: %s.\n", program,
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strerror (errno));
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||
fflush (stderr);
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||
_exit (0177);
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||
}
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||
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||
new_process = add_process (pid);
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||
add_thread (pid, new_process);
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||
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||
return 0;
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||
}
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||
|
||
/* Attach to an inferior process. */
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||
|
||
void
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||
linux_attach_lwp (int pid, int tid)
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||
{
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||
struct process_info *new_process;
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||
|
||
if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
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||
{
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||
fprintf (stderr, "Cannot attach to process %d: %s (%d)\n", pid,
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errno < sys_nerr ? sys_errlist[errno] : "unknown error",
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errno);
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fflush (stderr);
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||
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||
/* If we fail to attach to an LWP, just return. */
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||
if (!using_threads)
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_exit (0177);
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return;
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}
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||
new_process = (struct process_info *) add_process (pid);
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add_thread (tid, new_process);
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||
|
||
/* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
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brings it to a halt. We should ignore that SIGSTOP and resume the process
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(unless this is the first process, in which case the flag will be cleared
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||
in linux_attach).
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|
||
On the other hand, if we are currently trying to stop all threads, we
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should treat the new thread as if we had sent it a SIGSTOP. This works
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because we are guaranteed that add_process added us to the end of the
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list, and so the new thread has not yet reached wait_for_sigstop (but
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will). */
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if (! stopping_threads)
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new_process->stop_expected = 1;
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}
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int
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linux_attach (int pid)
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||
{
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struct process_info *process;
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linux_attach_lwp (pid, pid);
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/* Don't ignore the initial SIGSTOP if we just attached to this process. */
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process = (struct process_info *) find_inferior_id (&all_processes, pid);
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process->stop_expected = 0;
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return 0;
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}
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||
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||
/* Kill the inferior process. Make us have no inferior. */
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||
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||
static void
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linux_kill_one_process (struct inferior_list_entry *entry)
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{
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struct thread_info *thread = (struct thread_info *) entry;
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struct process_info *process = get_thread_process (thread);
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int wstat;
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do
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{
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ptrace (PTRACE_KILL, pid_of (process), 0, 0);
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/* Make sure it died. The loop is most likely unnecessary. */
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wstat = linux_wait_for_event (thread);
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} while (WIFSTOPPED (wstat));
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}
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||
/* Return nonzero if the given thread is still alive. */
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||
static void
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||
linux_kill (void)
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||
{
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for_each_inferior (&all_threads, linux_kill_one_process);
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||
}
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|
||
static int
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||
linux_thread_alive (int tid)
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||
{
|
||
if (find_inferior_id (&all_threads, tid) != NULL)
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return 1;
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||
else
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return 0;
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||
}
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/* Return nonzero if this process stopped at a breakpoint which
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no longer appears to be inserted. Also adjust the PC
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appropriately to resume where the breakpoint used to be. */
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static int
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||
check_removed_breakpoint (struct process_info *event_child)
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||
{
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CORE_ADDR stop_pc;
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struct thread_info *saved_inferior;
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if (event_child->pending_is_breakpoint == 0)
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return 0;
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||
|
||
if (debug_threads)
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fprintf (stderr, "Checking for breakpoint.\n");
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saved_inferior = current_inferior;
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current_inferior = get_process_thread (event_child);
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||
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||
stop_pc = get_stop_pc ();
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||
|
||
/* If the PC has changed since we stopped, then we shouldn't do
|
||
anything. This happens if, for instance, GDB handled the
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decr_pc_after_break subtraction itself. */
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if (stop_pc != event_child->pending_stop_pc)
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||
{
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||
if (debug_threads)
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fprintf (stderr, "Ignoring, PC was changed.\n");
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||
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||
event_child->pending_is_breakpoint = 0;
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current_inferior = saved_inferior;
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||
return 0;
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||
}
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||
|
||
/* If the breakpoint is still there, we will report hitting it. */
|
||
if ((*the_low_target.breakpoint_at) (stop_pc))
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||
{
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||
if (debug_threads)
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||
fprintf (stderr, "Ignoring, breakpoint is still present.\n");
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current_inferior = saved_inferior;
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||
return 0;
|
||
}
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||
|
||
if (debug_threads)
|
||
fprintf (stderr, "Removed breakpoint.\n");
|
||
|
||
/* For decr_pc_after_break targets, here is where we perform the
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decrement. We go immediately from this function to resuming,
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and can not safely call get_stop_pc () again. */
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||
if (the_low_target.set_pc != NULL)
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(*the_low_target.set_pc) (stop_pc);
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|
||
/* We consumed the pending SIGTRAP. */
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||
event_child->status_pending_p = 0;
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event_child->status_pending = 0;
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current_inferior = saved_inferior;
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return 1;
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||
}
|
||
|
||
/* Return 1 if this process has an interesting status pending. This function
|
||
may silently resume an inferior process. */
|
||
static int
|
||
status_pending_p (struct inferior_list_entry *entry, void *dummy)
|
||
{
|
||
struct process_info *process = (struct process_info *) entry;
|
||
|
||
if (process->status_pending_p)
|
||
if (check_removed_breakpoint (process))
|
||
{
|
||
/* This thread was stopped at a breakpoint, and the breakpoint
|
||
is now gone. We were told to continue (or step...) all threads,
|
||
so GDB isn't trying to single-step past this breakpoint.
|
||
So instead of reporting the old SIGTRAP, pretend we got to
|
||
the breakpoint just after it was removed instead of just
|
||
before; resume the process. */
|
||
linux_resume_one_process (&process->head, 0, 0);
|
||
return 0;
|
||
}
|
||
|
||
return process->status_pending_p;
|
||
}
|
||
|
||
static void
|
||
linux_wait_for_process (struct process_info **childp, int *wstatp)
|
||
{
|
||
int ret;
|
||
int to_wait_for = -1;
|
||
|
||
if (*childp != NULL)
|
||
to_wait_for = (*childp)->lwpid;
|
||
|
||
while (1)
|
||
{
|
||
ret = waitpid (to_wait_for, wstatp, WNOHANG);
|
||
|
||
if (ret == -1)
|
||
{
|
||
if (errno != ECHILD)
|
||
perror_with_name ("waitpid");
|
||
}
|
||
else if (ret > 0)
|
||
break;
|
||
|
||
ret = waitpid (to_wait_for, wstatp, WNOHANG | __WCLONE);
|
||
|
||
if (ret == -1)
|
||
{
|
||
if (errno != ECHILD)
|
||
perror_with_name ("waitpid (WCLONE)");
|
||
}
|
||
else if (ret > 0)
|
||
break;
|
||
|
||
usleep (1000);
|
||
}
|
||
|
||
if (debug_threads
|
||
&& (!WIFSTOPPED (*wstatp)
|
||
|| (WSTOPSIG (*wstatp) != 32
|
||
&& WSTOPSIG (*wstatp) != 33)))
|
||
fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
|
||
|
||
if (to_wait_for == -1)
|
||
*childp = (struct process_info *) find_inferior_id (&all_processes, ret);
|
||
|
||
(*childp)->stopped = 1;
|
||
(*childp)->pending_is_breakpoint = 0;
|
||
|
||
if (debug_threads
|
||
&& WIFSTOPPED (*wstatp))
|
||
{
|
||
current_inferior = (struct thread_info *)
|
||
find_inferior_id (&all_threads, (*childp)->tid);
|
||
/* For testing only; i386_stop_pc prints out a diagnostic. */
|
||
if (the_low_target.get_pc != NULL)
|
||
get_stop_pc ();
|
||
}
|
||
}
|
||
|
||
static int
|
||
linux_wait_for_event (struct thread_info *child)
|
||
{
|
||
CORE_ADDR stop_pc;
|
||
struct process_info *event_child;
|
||
int wstat;
|
||
|
||
/* Check for a process with a pending status. */
|
||
/* It is possible that the user changed the pending task's registers since
|
||
it stopped. We correctly handle the change of PC if we hit a breakpoint
|
||
(in check_removed_breakpoints); signals should be reported anyway. */
|
||
if (child == NULL)
|
||
{
|
||
event_child = (struct process_info *)
|
||
find_inferior (&all_processes, status_pending_p, NULL);
|
||
if (debug_threads && event_child)
|
||
fprintf (stderr, "Got a pending child %d\n", event_child->lwpid);
|
||
}
|
||
else
|
||
{
|
||
event_child = get_thread_process (child);
|
||
if (event_child->status_pending_p
|
||
&& check_removed_breakpoint (event_child))
|
||
event_child = NULL;
|
||
}
|
||
|
||
if (event_child != NULL)
|
||
{
|
||
if (event_child->status_pending_p)
|
||
{
|
||
if (debug_threads)
|
||
fprintf (stderr, "Got an event from pending child %d (%04x)\n",
|
||
event_child->lwpid, event_child->status_pending);
|
||
wstat = event_child->status_pending;
|
||
event_child->status_pending_p = 0;
|
||
event_child->status_pending = 0;
|
||
current_inferior = get_process_thread (event_child);
|
||
return wstat;
|
||
}
|
||
}
|
||
|
||
/* We only enter this loop if no process has a pending wait status. Thus
|
||
any action taken in response to a wait status inside this loop is
|
||
responding as soon as we detect the status, not after any pending
|
||
events. */
|
||
while (1)
|
||
{
|
||
if (child == NULL)
|
||
event_child = NULL;
|
||
else
|
||
event_child = get_thread_process (child);
|
||
|
||
linux_wait_for_process (&event_child, &wstat);
|
||
|
||
if (event_child == NULL)
|
||
error ("event from unknown child");
|
||
|
||
current_inferior = (struct thread_info *)
|
||
find_inferior_id (&all_threads, event_child->tid);
|
||
|
||
if (using_threads)
|
||
{
|
||
/* Check for thread exit. */
|
||
if (! WIFSTOPPED (wstat))
|
||
{
|
||
if (debug_threads)
|
||
fprintf (stderr, "Thread %d (LWP %d) exiting\n",
|
||
event_child->tid, event_child->head.id);
|
||
|
||
/* If the last thread is exiting, just return. */
|
||
if (all_threads.head == all_threads.tail)
|
||
return wstat;
|
||
|
||
dead_thread_notify (event_child->tid);
|
||
|
||
remove_inferior (&all_processes, &event_child->head);
|
||
free (event_child);
|
||
remove_thread (current_inferior);
|
||
current_inferior = (struct thread_info *) all_threads.head;
|
||
|
||
/* If we were waiting for this particular child to do something...
|
||
well, it did something. */
|
||
if (child != NULL)
|
||
return wstat;
|
||
|
||
/* Wait for a more interesting event. */
|
||
continue;
|
||
}
|
||
|
||
if (WIFSTOPPED (wstat)
|
||
&& WSTOPSIG (wstat) == SIGSTOP
|
||
&& event_child->stop_expected)
|
||
{
|
||
if (debug_threads)
|
||
fprintf (stderr, "Expected stop.\n");
|
||
event_child->stop_expected = 0;
|
||
linux_resume_one_process (&event_child->head,
|
||
event_child->stepping, 0);
|
||
continue;
|
||
}
|
||
|
||
/* FIXME drow/2002-06-09: Get signal numbers from the inferior's
|
||
thread library? */
|
||
if (WIFSTOPPED (wstat)
|
||
&& (WSTOPSIG (wstat) == SIGRTMIN
|
||
|| WSTOPSIG (wstat) == SIGRTMIN + 1))
|
||
{
|
||
if (debug_threads)
|
||
fprintf (stderr, "Ignored signal %d for %d (LWP %d).\n",
|
||
WSTOPSIG (wstat), event_child->tid,
|
||
event_child->head.id);
|
||
linux_resume_one_process (&event_child->head,
|
||
event_child->stepping,
|
||
WSTOPSIG (wstat));
|
||
continue;
|
||
}
|
||
}
|
||
|
||
/* If this event was not handled above, and is not a SIGTRAP, report
|
||
it. */
|
||
if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGTRAP)
|
||
return wstat;
|
||
|
||
/* If this target does not support breakpoints, we simply report the
|
||
SIGTRAP; it's of no concern to us. */
|
||
if (the_low_target.get_pc == NULL)
|
||
return wstat;
|
||
|
||
stop_pc = get_stop_pc ();
|
||
|
||
/* bp_reinsert will only be set if we were single-stepping.
|
||
Notice that we will resume the process after hitting
|
||
a gdbserver breakpoint; single-stepping to/over one
|
||
is not supported (yet). */
|
||
if (event_child->bp_reinsert != 0)
|
||
{
|
||
if (debug_threads)
|
||
fprintf (stderr, "Reinserted breakpoint.\n");
|
||
reinsert_breakpoint (event_child->bp_reinsert);
|
||
event_child->bp_reinsert = 0;
|
||
|
||
/* Clear the single-stepping flag and SIGTRAP as we resume. */
|
||
linux_resume_one_process (&event_child->head, 0, 0);
|
||
continue;
|
||
}
|
||
|
||
if (debug_threads)
|
||
fprintf (stderr, "Hit a (non-reinsert) breakpoint.\n");
|
||
|
||
if (check_breakpoints (stop_pc) != 0)
|
||
{
|
||
/* We hit one of our own breakpoints. We mark it as a pending
|
||
breakpoint, so that check_removed_breakpoints () will do the PC
|
||
adjustment for us at the appropriate time. */
|
||
event_child->pending_is_breakpoint = 1;
|
||
event_child->pending_stop_pc = stop_pc;
|
||
|
||
/* Now we need to put the breakpoint back. We continue in the event
|
||
loop instead of simply replacing the breakpoint right away,
|
||
in order to not lose signals sent to the thread that hit the
|
||
breakpoint. Unfortunately this increases the window where another
|
||
thread could sneak past the removed breakpoint. For the current
|
||
use of server-side breakpoints (thread creation) this is
|
||
acceptable; but it needs to be considered before this breakpoint
|
||
mechanism can be used in more general ways. For some breakpoints
|
||
it may be necessary to stop all other threads, but that should
|
||
be avoided where possible.
|
||
|
||
If breakpoint_reinsert_addr is NULL, that means that we can
|
||
use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
|
||
mark it for reinsertion, and single-step.
|
||
|
||
Otherwise, call the target function to figure out where we need
|
||
our temporary breakpoint, create it, and continue executing this
|
||
process. */
|
||
if (the_low_target.breakpoint_reinsert_addr == NULL)
|
||
{
|
||
event_child->bp_reinsert = stop_pc;
|
||
uninsert_breakpoint (stop_pc);
|
||
linux_resume_one_process (&event_child->head, 1, 0);
|
||
}
|
||
else
|
||
{
|
||
reinsert_breakpoint_by_bp
|
||
(stop_pc, (*the_low_target.breakpoint_reinsert_addr) ());
|
||
linux_resume_one_process (&event_child->head, 0, 0);
|
||
}
|
||
|
||
continue;
|
||
}
|
||
|
||
/* If we were single-stepping, we definitely want to report the
|
||
SIGTRAP. The single-step operation has completed, so also
|
||
clear the stepping flag; in general this does not matter,
|
||
because the SIGTRAP will be reported to the client, which
|
||
will give us a new action for this thread, but clear it for
|
||
consistency anyway. It's safe to clear the stepping flag
|
||
because the only consumer of get_stop_pc () after this point
|
||
is check_removed_breakpoints, and pending_is_breakpoint is not
|
||
set. It might be wiser to use a step_completed flag instead. */
|
||
if (event_child->stepping)
|
||
{
|
||
event_child->stepping = 0;
|
||
return wstat;
|
||
}
|
||
|
||
/* A SIGTRAP that we can't explain. It may have been a breakpoint.
|
||
Check if it is a breakpoint, and if so mark the process information
|
||
accordingly. This will handle both the necessary fiddling with the
|
||
PC on decr_pc_after_break targets and suppressing extra threads
|
||
hitting a breakpoint if two hit it at once and then GDB removes it
|
||
after the first is reported. Arguably it would be better to report
|
||
multiple threads hitting breakpoints simultaneously, but the current
|
||
remote protocol does not allow this. */
|
||
if ((*the_low_target.breakpoint_at) (stop_pc))
|
||
{
|
||
event_child->pending_is_breakpoint = 1;
|
||
event_child->pending_stop_pc = stop_pc;
|
||
}
|
||
|
||
return wstat;
|
||
}
|
||
|
||
/* NOTREACHED */
|
||
return 0;
|
||
}
|
||
|
||
/* Wait for process, returns status. */
|
||
|
||
static unsigned char
|
||
linux_wait (char *status)
|
||
{
|
||
int w;
|
||
struct thread_info *child = NULL;
|
||
|
||
retry:
|
||
/* If we were only supposed to resume one thread, only wait for
|
||
that thread - if it's still alive. If it died, however - which
|
||
can happen if we're coming from the thread death case below -
|
||
then we need to make sure we restart the other threads. We could
|
||
pick a thread at random or restart all; restarting all is less
|
||
arbitrary. */
|
||
if (cont_thread > 0)
|
||
{
|
||
child = (struct thread_info *) find_inferior_id (&all_threads,
|
||
cont_thread);
|
||
|
||
/* No stepping, no signal - unless one is pending already, of course. */
|
||
if (child == NULL)
|
||
linux_resume (0, 0);
|
||
}
|
||
|
||
enable_async_io ();
|
||
w = linux_wait_for_event (child);
|
||
stop_all_processes ();
|
||
disable_async_io ();
|
||
|
||
/* If we are waiting for a particular child, and it exited,
|
||
linux_wait_for_event will return its exit status. Similarly if
|
||
the last child exited. If this is not the last child, however,
|
||
do not report it as exited until there is a 'thread exited' response
|
||
available in the remote protocol. Instead, just wait for another event.
|
||
This should be safe, because if the thread crashed we will already
|
||
have reported the termination signal to GDB; that should stop any
|
||
in-progress stepping operations, etc.
|
||
|
||
Report the exit status of the last thread to exit. This matches
|
||
LinuxThreads' behavior. */
|
||
|
||
if (all_threads.head == all_threads.tail)
|
||
{
|
||
if (WIFEXITED (w))
|
||
{
|
||
fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
|
||
*status = 'W';
|
||
clear_inferiors ();
|
||
return ((unsigned char) WEXITSTATUS (w));
|
||
}
|
||
else if (!WIFSTOPPED (w))
|
||
{
|
||
fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
|
||
clear_inferiors ();
|
||
*status = 'X';
|
||
return ((unsigned char) WTERMSIG (w));
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (!WIFSTOPPED (w))
|
||
goto retry;
|
||
}
|
||
|
||
*status = 'T';
|
||
return ((unsigned char) WSTOPSIG (w));
|
||
}
|
||
|
||
static void
|
||
send_sigstop (struct inferior_list_entry *entry)
|
||
{
|
||
struct process_info *process = (struct process_info *) entry;
|
||
|
||
if (process->stopped)
|
||
return;
|
||
|
||
/* If we already have a pending stop signal for this process, don't
|
||
send another. */
|
||
if (process->stop_expected)
|
||
{
|
||
process->stop_expected = 0;
|
||
return;
|
||
}
|
||
|
||
if (debug_threads)
|
||
fprintf (stderr, "Sending sigstop to process %d\n", process->head.id);
|
||
|
||
kill (process->head.id, SIGSTOP);
|
||
process->sigstop_sent = 1;
|
||
}
|
||
|
||
static void
|
||
wait_for_sigstop (struct inferior_list_entry *entry)
|
||
{
|
||
struct process_info *process = (struct process_info *) entry;
|
||
struct thread_info *saved_inferior, *thread;
|
||
int wstat, saved_tid;
|
||
|
||
if (process->stopped)
|
||
return;
|
||
|
||
saved_inferior = current_inferior;
|
||
saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
|
||
thread = (struct thread_info *) find_inferior_id (&all_threads,
|
||
process->tid);
|
||
wstat = linux_wait_for_event (thread);
|
||
|
||
/* If we stopped with a non-SIGSTOP signal, save it for later
|
||
and record the pending SIGSTOP. If the process exited, just
|
||
return. */
|
||
if (WIFSTOPPED (wstat)
|
||
&& WSTOPSIG (wstat) != SIGSTOP)
|
||
{
|
||
if (debug_threads)
|
||
fprintf (stderr, "Stopped with non-sigstop signal\n");
|
||
process->status_pending_p = 1;
|
||
process->status_pending = wstat;
|
||
process->stop_expected = 1;
|
||
}
|
||
|
||
if (linux_thread_alive (saved_tid))
|
||
current_inferior = saved_inferior;
|
||
else
|
||
{
|
||
if (debug_threads)
|
||
fprintf (stderr, "Previously current thread died.\n");
|
||
|
||
/* Set a valid thread as current. */
|
||
set_desired_inferior (0);
|
||
}
|
||
}
|
||
|
||
static void
|
||
stop_all_processes (void)
|
||
{
|
||
stopping_threads = 1;
|
||
for_each_inferior (&all_processes, send_sigstop);
|
||
for_each_inferior (&all_processes, wait_for_sigstop);
|
||
stopping_threads = 0;
|
||
}
|
||
|
||
/* Resume execution of the inferior process.
|
||
If STEP is nonzero, single-step it.
|
||
If SIGNAL is nonzero, give it that signal. */
|
||
|
||
static void
|
||
linux_resume_one_process (struct inferior_list_entry *entry,
|
||
int step, int signal)
|
||
{
|
||
struct process_info *process = (struct process_info *) entry;
|
||
struct thread_info *saved_inferior;
|
||
|
||
if (process->stopped == 0)
|
||
return;
|
||
|
||
/* If we have pending signals or status, and a new signal, enqueue the
|
||
signal. Also enqueue the signal if we are waiting to reinsert a
|
||
breakpoint; it will be picked up again below. */
|
||
if (signal != 0
|
||
&& (process->status_pending_p || process->pending_signals != NULL
|
||
|| process->bp_reinsert != 0))
|
||
{
|
||
struct pending_signals *p_sig;
|
||
p_sig = malloc (sizeof (*p_sig));
|
||
p_sig->prev = process->pending_signals;
|
||
p_sig->signal = signal;
|
||
process->pending_signals = p_sig;
|
||
}
|
||
|
||
if (process->status_pending_p)
|
||
return;
|
||
|
||
saved_inferior = current_inferior;
|
||
current_inferior = get_process_thread (process);
|
||
|
||
if (debug_threads)
|
||
fprintf (stderr, "Resuming process %d (%s, signal %d, stop %s)\n", inferior_pid,
|
||
step ? "step" : "continue", signal,
|
||
process->stop_expected ? "expected" : "not expected");
|
||
|
||
/* This bit needs some thinking about. If we get a signal that
|
||
we must report while a single-step reinsert is still pending,
|
||
we often end up resuming the thread. It might be better to
|
||
(ew) allow a stack of pending events; then we could be sure that
|
||
the reinsert happened right away and not lose any signals.
|
||
|
||
Making this stack would also shrink the window in which breakpoints are
|
||
uninserted (see comment in linux_wait_for_process) but not enough for
|
||
complete correctness, so it won't solve that problem. It may be
|
||
worthwhile just to solve this one, however. */
|
||
if (process->bp_reinsert != 0)
|
||
{
|
||
if (debug_threads)
|
||
fprintf (stderr, " pending reinsert at %08lx", (long)process->bp_reinsert);
|
||
if (step == 0)
|
||
fprintf (stderr, "BAD - reinserting but not stepping.\n");
|
||
step = 1;
|
||
|
||
/* Postpone any pending signal. It was enqueued above. */
|
||
signal = 0;
|
||
}
|
||
|
||
check_removed_breakpoint (process);
|
||
|
||
if (debug_threads && the_low_target.get_pc != NULL)
|
||
{
|
||
fprintf (stderr, " ");
|
||
(long) (*the_low_target.get_pc) ();
|
||
}
|
||
|
||
/* If we have pending signals, consume one unless we are trying to reinsert
|
||
a breakpoint. */
|
||
if (process->pending_signals != NULL && process->bp_reinsert == 0)
|
||
{
|
||
struct pending_signals **p_sig;
|
||
|
||
p_sig = &process->pending_signals;
|
||
while ((*p_sig)->prev != NULL)
|
||
p_sig = &(*p_sig)->prev;
|
||
|
||
signal = (*p_sig)->signal;
|
||
free (*p_sig);
|
||
*p_sig = NULL;
|
||
}
|
||
|
||
regcache_invalidate_one ((struct inferior_list_entry *)
|
||
get_process_thread (process));
|
||
errno = 0;
|
||
process->stopped = 0;
|
||
process->stepping = step;
|
||
ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, process->lwpid, 0, signal);
|
||
|
||
current_inferior = saved_inferior;
|
||
if (errno)
|
||
perror_with_name ("ptrace");
|
||
}
|
||
|
||
/* This function is called once per process other than the first
|
||
one. The first process we are told the signal to continue
|
||
with, and whether to step or continue; for all others, any
|
||
existing signals will be marked in status_pending_p to be
|
||
reported momentarily, and we preserve the stepping flag. */
|
||
static void
|
||
linux_continue_one_process (struct inferior_list_entry *entry)
|
||
{
|
||
struct process_info *process;
|
||
|
||
process = (struct process_info *) entry;
|
||
linux_resume_one_process (entry, process->stepping, 0);
|
||
}
|
||
|
||
static void
|
||
linux_resume (int step, int signal)
|
||
{
|
||
struct process_info *process;
|
||
|
||
process = get_thread_process (current_inferior);
|
||
|
||
/* If the current process has a status pending, this signal will
|
||
be enqueued and sent later. */
|
||
linux_resume_one_process (&process->head, step, signal);
|
||
|
||
if (cont_thread == 0 || cont_thread == -1)
|
||
for_each_inferior (&all_processes, linux_continue_one_process);
|
||
}
|
||
|
||
#ifdef HAVE_LINUX_USRREGS
|
||
|
||
int
|
||
register_addr (int regnum)
|
||
{
|
||
int addr;
|
||
|
||
if (regnum < 0 || regnum >= the_low_target.num_regs)
|
||
error ("Invalid register number %d.", regnum);
|
||
|
||
addr = the_low_target.regmap[regnum];
|
||
if (addr == -1)
|
||
addr = 0;
|
||
|
||
return addr;
|
||
}
|
||
|
||
/* Fetch one register. */
|
||
static void
|
||
fetch_register (int regno)
|
||
{
|
||
CORE_ADDR regaddr;
|
||
register int i;
|
||
char *buf;
|
||
|
||
if (regno >= the_low_target.num_regs)
|
||
return;
|
||
if ((*the_low_target.cannot_fetch_register) (regno))
|
||
return;
|
||
|
||
regaddr = register_addr (regno);
|
||
if (regaddr == -1)
|
||
return;
|
||
buf = alloca (register_size (regno));
|
||
for (i = 0; i < register_size (regno); i += sizeof (PTRACE_XFER_TYPE))
|
||
{
|
||
errno = 0;
|
||
*(PTRACE_XFER_TYPE *) (buf + i) =
|
||
ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0);
|
||
regaddr += sizeof (PTRACE_XFER_TYPE);
|
||
if (errno != 0)
|
||
{
|
||
/* Warning, not error, in case we are attached; sometimes the
|
||
kernel doesn't let us at the registers. */
|
||
char *err = strerror (errno);
|
||
char *msg = alloca (strlen (err) + 128);
|
||
sprintf (msg, "reading register %d: %s", regno, err);
|
||
error (msg);
|
||
goto error_exit;
|
||
}
|
||
}
|
||
supply_register (regno, buf);
|
||
|
||
error_exit:;
|
||
}
|
||
|
||
/* Fetch all registers, or just one, from the child process. */
|
||
static void
|
||
usr_fetch_inferior_registers (int regno)
|
||
{
|
||
if (regno == -1 || regno == 0)
|
||
for (regno = 0; regno < the_low_target.num_regs; regno++)
|
||
fetch_register (regno);
|
||
else
|
||
fetch_register (regno);
|
||
}
|
||
|
||
/* Store our register values back into the inferior.
|
||
If REGNO is -1, do this for all registers.
|
||
Otherwise, REGNO specifies which register (so we can save time). */
|
||
static void
|
||
usr_store_inferior_registers (int regno)
|
||
{
|
||
CORE_ADDR regaddr;
|
||
int i;
|
||
char *buf;
|
||
|
||
if (regno >= 0)
|
||
{
|
||
if (regno >= the_low_target.num_regs)
|
||
return;
|
||
|
||
if ((*the_low_target.cannot_store_register) (regno) == 1)
|
||
return;
|
||
|
||
regaddr = register_addr (regno);
|
||
if (regaddr == -1)
|
||
return;
|
||
errno = 0;
|
||
buf = alloca (register_size (regno));
|
||
collect_register (regno, buf);
|
||
for (i = 0; i < register_size (regno); i += sizeof (PTRACE_XFER_TYPE))
|
||
{
|
||
errno = 0;
|
||
ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
|
||
*(int *) (buf + i));
|
||
if (errno != 0)
|
||
{
|
||
if ((*the_low_target.cannot_store_register) (regno) == 0)
|
||
{
|
||
char *err = strerror (errno);
|
||
char *msg = alloca (strlen (err) + 128);
|
||
sprintf (msg, "writing register %d: %s",
|
||
regno, err);
|
||
error (msg);
|
||
return;
|
||
}
|
||
}
|
||
regaddr += sizeof (int);
|
||
}
|
||
}
|
||
else
|
||
for (regno = 0; regno < the_low_target.num_regs; regno++)
|
||
usr_store_inferior_registers (regno);
|
||
}
|
||
#endif /* HAVE_LINUX_USRREGS */
|
||
|
||
|
||
|
||
#ifdef HAVE_LINUX_REGSETS
|
||
|
||
static int
|
||
regsets_fetch_inferior_registers ()
|
||
{
|
||
struct regset_info *regset;
|
||
|
||
regset = target_regsets;
|
||
|
||
while (regset->size >= 0)
|
||
{
|
||
void *buf;
|
||
int res;
|
||
|
||
if (regset->size == 0)
|
||
{
|
||
regset ++;
|
||
continue;
|
||
}
|
||
|
||
buf = malloc (regset->size);
|
||
res = ptrace (regset->get_request, inferior_pid, 0, buf);
|
||
if (res < 0)
|
||
{
|
||
if (errno == EIO)
|
||
{
|
||
/* If we get EIO on the first regset, do not try regsets again.
|
||
If we get EIO on a later regset, disable that regset. */
|
||
if (regset == target_regsets)
|
||
{
|
||
use_regsets_p = 0;
|
||
return -1;
|
||
}
|
||
else
|
||
{
|
||
regset->size = 0;
|
||
continue;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
char s[256];
|
||
sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
|
||
inferior_pid);
|
||
perror (s);
|
||
}
|
||
}
|
||
regset->store_function (buf);
|
||
regset ++;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
static int
|
||
regsets_store_inferior_registers ()
|
||
{
|
||
struct regset_info *regset;
|
||
|
||
regset = target_regsets;
|
||
|
||
while (regset->size >= 0)
|
||
{
|
||
void *buf;
|
||
int res;
|
||
|
||
if (regset->size == 0)
|
||
{
|
||
regset ++;
|
||
continue;
|
||
}
|
||
|
||
buf = malloc (regset->size);
|
||
regset->fill_function (buf);
|
||
res = ptrace (regset->set_request, inferior_pid, 0, buf);
|
||
if (res < 0)
|
||
{
|
||
if (errno == EIO)
|
||
{
|
||
/* If we get EIO on the first regset, do not try regsets again.
|
||
If we get EIO on a later regset, disable that regset. */
|
||
if (regset == target_regsets)
|
||
{
|
||
use_regsets_p = 0;
|
||
return -1;
|
||
}
|
||
else
|
||
{
|
||
regset->size = 0;
|
||
continue;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
perror ("Warning: ptrace(regsets_store_inferior_registers)");
|
||
}
|
||
}
|
||
regset ++;
|
||
free (buf);
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
#endif /* HAVE_LINUX_REGSETS */
|
||
|
||
|
||
void
|
||
linux_fetch_registers (int regno)
|
||
{
|
||
#ifdef HAVE_LINUX_REGSETS
|
||
if (use_regsets_p)
|
||
{
|
||
if (regsets_fetch_inferior_registers () == 0)
|
||
return;
|
||
}
|
||
#endif
|
||
#ifdef HAVE_LINUX_USRREGS
|
||
usr_fetch_inferior_registers (regno);
|
||
#endif
|
||
}
|
||
|
||
void
|
||
linux_store_registers (int regno)
|
||
{
|
||
#ifdef HAVE_LINUX_REGSETS
|
||
if (use_regsets_p)
|
||
{
|
||
if (regsets_store_inferior_registers () == 0)
|
||
return;
|
||
}
|
||
#endif
|
||
#ifdef HAVE_LINUX_USRREGS
|
||
usr_store_inferior_registers (regno);
|
||
#endif
|
||
}
|
||
|
||
|
||
/* Copy LEN bytes from inferior's memory starting at MEMADDR
|
||
to debugger memory starting at MYADDR. */
|
||
|
||
static void
|
||
linux_read_memory (CORE_ADDR memaddr, char *myaddr, int len)
|
||
{
|
||
register int i;
|
||
/* Round starting address down to longword boundary. */
|
||
register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
|
||
/* Round ending address up; get number of longwords that makes. */
|
||
register int count
|
||
= (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
|
||
/ sizeof (PTRACE_XFER_TYPE);
|
||
/* Allocate buffer of that many longwords. */
|
||
register PTRACE_XFER_TYPE *buffer
|
||
= (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
|
||
|
||
/* Read all the longwords */
|
||
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
|
||
{
|
||
buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, 0);
|
||
}
|
||
|
||
/* Copy appropriate bytes out of the buffer. */
|
||
memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len);
|
||
}
|
||
|
||
/* Copy LEN bytes of data from debugger memory at MYADDR
|
||
to inferior's memory at MEMADDR.
|
||
On failure (cannot write the inferior)
|
||
returns the value of errno. */
|
||
|
||
static int
|
||
linux_write_memory (CORE_ADDR memaddr, const char *myaddr, int len)
|
||
{
|
||
register int i;
|
||
/* Round starting address down to longword boundary. */
|
||
register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
|
||
/* Round ending address up; get number of longwords that makes. */
|
||
register int count
|
||
= (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE);
|
||
/* Allocate buffer of that many longwords. */
|
||
register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
|
||
extern int errno;
|
||
|
||
if (debug_threads)
|
||
{
|
||
fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr);
|
||
}
|
||
|
||
/* Fill start and end extra bytes of buffer with existing memory data. */
|
||
|
||
buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
|
||
(PTRACE_ARG3_TYPE) addr, 0);
|
||
|
||
if (count > 1)
|
||
{
|
||
buffer[count - 1]
|
||
= ptrace (PTRACE_PEEKTEXT, inferior_pid,
|
||
(PTRACE_ARG3_TYPE) (addr + (count - 1)
|
||
* sizeof (PTRACE_XFER_TYPE)),
|
||
0);
|
||
}
|
||
|
||
/* Copy data to be written over corresponding part of buffer */
|
||
|
||
memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
|
||
|
||
/* Write the entire buffer. */
|
||
|
||
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
|
||
{
|
||
errno = 0;
|
||
ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]);
|
||
if (errno)
|
||
return errno;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
linux_look_up_symbols (void)
|
||
{
|
||
#ifdef USE_THREAD_DB
|
||
if (using_threads)
|
||
return;
|
||
|
||
using_threads = thread_db_init ();
|
||
#endif
|
||
}
|
||
|
||
/* Return 1 if this process is not stopped. */
|
||
static int
|
||
unstopped_p (struct inferior_list_entry *entry, void *dummy)
|
||
{
|
||
struct process_info *process = (struct process_info *) entry;
|
||
|
||
if (process->stopped)
|
||
return 0;
|
||
|
||
return 1;
|
||
}
|
||
|
||
static int
|
||
linux_signal_pid ()
|
||
{
|
||
struct inferior_list_entry *process;
|
||
|
||
process = find_inferior (&all_processes, unstopped_p, NULL);
|
||
|
||
if (process == NULL)
|
||
{
|
||
warning ("no unstopped process");
|
||
return inferior_pid;
|
||
}
|
||
|
||
return pid_of ((struct process_info *) process);
|
||
}
|
||
|
||
|
||
static struct target_ops linux_target_ops = {
|
||
linux_create_inferior,
|
||
linux_attach,
|
||
linux_kill,
|
||
linux_thread_alive,
|
||
linux_resume,
|
||
linux_wait,
|
||
linux_fetch_registers,
|
||
linux_store_registers,
|
||
linux_read_memory,
|
||
linux_write_memory,
|
||
linux_look_up_symbols,
|
||
linux_signal_pid,
|
||
};
|
||
|
||
static void
|
||
linux_init_signals ()
|
||
{
|
||
/* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
|
||
to find what the cancel signal actually is. */
|
||
signal (SIGRTMIN+1, SIG_IGN);
|
||
}
|
||
|
||
void
|
||
initialize_low (void)
|
||
{
|
||
using_threads = 0;
|
||
set_target_ops (&linux_target_ops);
|
||
set_breakpoint_data (the_low_target.breakpoint,
|
||
the_low_target.breakpoint_len);
|
||
init_registers ();
|
||
linux_init_signals ();
|
||
}
|