244 lines
6.8 KiB
C
244 lines
6.8 KiB
C
/*
|
|
* Server-side ptrace support
|
|
*
|
|
* Copyright (C) 1999 Alexandre Julliard
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* This library 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
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#include <signal.h>
|
|
#include <sys/types.h>
|
|
#ifdef HAVE_SYS_PTRACE_H
|
|
# include <sys/ptrace.h>
|
|
#endif
|
|
#ifdef HAVE_SYS_WAIT_H
|
|
# include <sys/wait.h>
|
|
#endif
|
|
#include <unistd.h>
|
|
|
|
#include "file.h"
|
|
#include "process.h"
|
|
#include "thread.h"
|
|
|
|
#ifndef PTRACE_CONT
|
|
#define PTRACE_CONT PT_CONTINUE
|
|
#endif
|
|
#ifndef PTRACE_SINGLESTEP
|
|
#define PTRACE_SINGLESTEP PT_STEP
|
|
#endif
|
|
#ifndef PTRACE_ATTACH
|
|
#define PTRACE_ATTACH PT_ATTACH
|
|
#endif
|
|
#ifndef PTRACE_DETACH
|
|
#define PTRACE_DETACH PT_DETACH
|
|
#endif
|
|
#ifndef PTRACE_PEEKDATA
|
|
#define PTRACE_PEEKDATA PT_READ_D
|
|
#endif
|
|
#ifndef PTRACE_POKEDATA
|
|
#define PTRACE_POKEDATA PT_WRITE_D
|
|
#endif
|
|
|
|
#ifndef HAVE_SYS_PTRACE_H
|
|
#define PT_CONTINUE 0
|
|
#define PT_ATTACH 1
|
|
#define PT_DETACH 2
|
|
#define PT_READ_D 3
|
|
#define PT_WRITE_D 4
|
|
#define PT_STEP 5
|
|
inline static int ptrace(int req, ...) { errno = EPERM; return -1; /*FAIL*/ }
|
|
#endif /* HAVE_SYS_PTRACE_H */
|
|
|
|
static const int use_ptrace = 1; /* set to 0 to disable ptrace */
|
|
|
|
/* handle a status returned by wait4 */
|
|
static int handle_child_status( struct thread *thread, int pid, int status, int want_sig )
|
|
{
|
|
if (WIFSTOPPED(status))
|
|
{
|
|
int sig = WSTOPSIG(status);
|
|
if (debug_level && thread)
|
|
fprintf( stderr, "%04x: *signal* signal=%d\n", thread->id, sig );
|
|
if (sig != want_sig)
|
|
{
|
|
/* ignore other signals for now */
|
|
if (thread && get_thread_single_step( thread ))
|
|
ptrace( PTRACE_SINGLESTEP, pid, (caddr_t)1, sig );
|
|
else
|
|
ptrace( PTRACE_CONT, pid, (caddr_t)1, sig );
|
|
}
|
|
return sig;
|
|
}
|
|
if (thread && (WIFSIGNALED(status) || WIFEXITED(status)))
|
|
{
|
|
thread->attached = 0;
|
|
thread->unix_pid = -1;
|
|
if (debug_level)
|
|
{
|
|
if (WIFSIGNALED(status))
|
|
fprintf( stderr, "%04x: *exited* signal=%d\n",
|
|
thread->id, WTERMSIG(status) );
|
|
else
|
|
fprintf( stderr, "%04x: *exited* status=%d\n",
|
|
thread->id, WEXITSTATUS(status) );
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* handle a SIGCHLD signal */
|
|
void sigchld_handler()
|
|
{
|
|
int pid, status;
|
|
|
|
for (;;)
|
|
{
|
|
if (!(pid = wait4( -1, &status, WUNTRACED | WNOHANG, NULL ))) break;
|
|
if (pid != -1) handle_child_status( get_thread_from_pid(pid), pid, status, -1 );
|
|
else break;
|
|
}
|
|
}
|
|
|
|
/* wait for a ptraced child to get a certain signal */
|
|
static void wait4_thread( struct thread *thread, int signal )
|
|
{
|
|
int res, status;
|
|
|
|
do
|
|
{
|
|
if ((res = wait4( thread->unix_pid, &status, WUNTRACED, NULL )) == -1)
|
|
{
|
|
if (errno == ECHILD) /* must have died */
|
|
{
|
|
thread->unix_pid = -1;
|
|
thread->attached = 0;
|
|
}
|
|
else perror( "wait4" );
|
|
return;
|
|
}
|
|
res = handle_child_status( thread, res, status, signal );
|
|
} while (res && res != signal);
|
|
}
|
|
|
|
/* send a Unix signal to a specific thread */
|
|
int send_thread_signal( struct thread *thread, int sig )
|
|
{
|
|
int ret = -1;
|
|
|
|
if (thread->unix_pid != -1)
|
|
{
|
|
ret = kill( thread->unix_pid, sig );
|
|
if (ret == -1 && errno == ESRCH) /* thread got killed */
|
|
{
|
|
thread->unix_pid = -1;
|
|
thread->attached = 0;
|
|
}
|
|
}
|
|
return (ret != -1);
|
|
}
|
|
|
|
/* attach to a Unix thread */
|
|
static int attach_thread( struct thread *thread )
|
|
{
|
|
/* this may fail if the client is already being debugged */
|
|
if (!use_ptrace) return 0;
|
|
if (ptrace( PTRACE_ATTACH, thread->unix_pid, 0, 0 ) == -1)
|
|
{
|
|
if (errno == ESRCH) thread->unix_pid = -1; /* thread got killed */
|
|
return 0;
|
|
}
|
|
if (debug_level) fprintf( stderr, "%04x: *attached*\n", thread->id );
|
|
thread->attached = 1;
|
|
wait4_thread( thread, SIGSTOP );
|
|
return 1;
|
|
}
|
|
|
|
/* detach from a Unix thread and kill it */
|
|
void detach_thread( struct thread *thread, int sig )
|
|
{
|
|
if (thread->unix_pid == -1) return;
|
|
if (thread->attached)
|
|
{
|
|
/* make sure it is stopped */
|
|
suspend_for_ptrace( thread );
|
|
if (sig) send_thread_signal( thread, sig );
|
|
if (thread->unix_pid == -1) return;
|
|
if (debug_level) fprintf( stderr, "%04x: *detached*\n", thread->id );
|
|
ptrace( PTRACE_DETACH, thread->unix_pid, (caddr_t)1, sig );
|
|
thread->attached = 0;
|
|
}
|
|
else if (sig) send_thread_signal( thread, sig );
|
|
}
|
|
|
|
/* suspend a thread to allow using ptrace on it */
|
|
/* you must do a resume_after_ptrace when finished with the thread */
|
|
int suspend_for_ptrace( struct thread *thread )
|
|
{
|
|
/* can't stop a thread while initialisation is in progress */
|
|
if (thread->unix_pid == -1 || !is_process_init_done(thread->process)) goto error;
|
|
|
|
if (thread->attached)
|
|
{
|
|
send_thread_signal( thread, SIGSTOP );
|
|
wait4_thread( thread, SIGSTOP );
|
|
return 1;
|
|
}
|
|
if (attach_thread( thread )) return 1;
|
|
error:
|
|
set_error( STATUS_ACCESS_DENIED );
|
|
return 0;
|
|
}
|
|
|
|
/* resume a thread after we have used pthread on it */
|
|
void resume_after_ptrace( struct thread *thread )
|
|
{
|
|
if (thread->unix_pid == -1) return;
|
|
assert( thread->attached );
|
|
ptrace( get_thread_single_step(thread) ? PTRACE_SINGLESTEP : PTRACE_CONT,
|
|
thread->unix_pid, (caddr_t)1, 0 /* cancel the SIGSTOP */ );
|
|
}
|
|
|
|
/* read an int from a thread address space */
|
|
int read_thread_int( struct thread *thread, const int *addr, int *data )
|
|
{
|
|
errno = 0;
|
|
*data = ptrace( PTRACE_PEEKDATA, thread->unix_pid, (caddr_t)addr, 0 );
|
|
if ( *data == -1 && errno)
|
|
{
|
|
file_set_error();
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* write an int to a thread address space */
|
|
int write_thread_int( struct thread *thread, int *addr, int data, unsigned int mask )
|
|
{
|
|
int res;
|
|
if (mask != ~0)
|
|
{
|
|
if (read_thread_int( thread, addr, &res ) == -1) return -1;
|
|
data = (data & mask) | (res & ~mask);
|
|
}
|
|
if ((res = ptrace( PTRACE_POKEDATA, thread->unix_pid, (caddr_t)addr, data )) == -1)
|
|
file_set_error();
|
|
return res;
|
|
}
|