2 * Server-side ptrace support
4 * Copyright (C) 1999 Alexandre Julliard
13 #include <sys/types.h>
14 #ifdef HAVE_SYS_PTRACE_H
15 # include <sys/ptrace.h>
17 #ifdef HAVE_SYS_WAIT_H
18 # include <sys/wait.h>
27 #define PTRACE_CONT PT_CONTINUE
29 #ifndef PTRACE_SINGLESTEP
30 #define PTRACE_SINGLESTEP PT_STEP
33 #define PTRACE_ATTACH PT_ATTACH
36 #define PTRACE_DETACH PT_DETACH
38 #ifndef PTRACE_PEEKDATA
39 #define PTRACE_PEEKDATA PT_READ_D
41 #ifndef PTRACE_POKEDATA
42 #define PTRACE_POKEDATA PT_WRITE_D
45 #ifdef HAVE_SYS_PTRACE_H
46 static const int use_ptrace
= 1; /* set to 0 to disable ptrace */
48 static const int use_ptrace
= 0;
57 static int ptrace(int req
, ...) { return -1; /*FAIL*/ }
60 /* handle a status returned by wait4 */
61 static int handle_child_status( struct thread
*thread
, int pid
, int status
)
63 if (WIFSTOPPED(status
))
65 int sig
= WSTOPSIG(status
);
66 if (debug_level
&& thread
)
67 fprintf( stderr
, "%08x: *signal* signal=%d\n", (unsigned int)thread
, sig
);
70 case SIGSTOP
: /* continue at once if not suspended */
71 if (thread
&& (thread
->process
->suspend
+ thread
->suspend
)) break;
73 default: /* ignore other signals for now */
74 if (thread
&& get_thread_single_step( thread
))
75 ptrace( PTRACE_SINGLESTEP
, pid
, (caddr_t
)1, sig
);
77 ptrace( PTRACE_CONT
, pid
, (caddr_t
)1, sig
);
82 if (thread
&& (WIFSIGNALED(status
) || WIFEXITED(status
)))
88 if (WIFSIGNALED(status
))
89 fprintf( stderr
, "%08x: *exited* signal=%d\n",
90 (unsigned int)thread
, WTERMSIG(status
) );
92 fprintf( stderr
, "%08x: *exited* status=%d\n",
93 (unsigned int)thread
, WEXITSTATUS(status
) );
99 /* handle a SIGCHLD signal */
100 void sigchld_handler()
106 if (!(pid
= wait4( -1, &status
, WUNTRACED
| WNOHANG
, NULL
))) break;
107 if (pid
!= -1) handle_child_status( get_thread_from_pid(pid
), pid
, status
);
112 /* wait for a ptraced child to get a certain signal */
113 void wait4_thread( struct thread
*thread
, int signal
)
119 if ((res
= wait4( thread
->unix_pid
, &status
, WUNTRACED
, NULL
)) == -1)
124 res
= handle_child_status( thread
, res
, status
);
125 } while (res
&& res
!= signal
);
128 /* attach to a Unix thread */
129 static int attach_thread( struct thread
*thread
)
131 /* this may fail if the client is already being debugged */
132 if (!use_ptrace
|| (ptrace( PTRACE_ATTACH
, thread
->unix_pid
, 0, 0 ) == -1)) return 0;
133 if (debug_level
) fprintf( stderr
, "%08x: *attached*\n", (unsigned int)thread
);
134 thread
->attached
= 1;
135 wait4_thread( thread
, SIGSTOP
);
139 /* detach from a Unix thread and kill it */
140 void detach_thread( struct thread
*thread
, int sig
)
142 if (!thread
->unix_pid
) return;
143 if (thread
->attached
)
145 /* make sure it is stopped */
146 if (!(thread
->suspend
+ thread
->process
->suspend
)) stop_thread( thread
);
147 if (sig
) kill( thread
->unix_pid
, sig
);
148 if (debug_level
) fprintf( stderr
, "%08x: *detached*\n", (unsigned int)thread
);
149 ptrace( PTRACE_DETACH
, thread
->unix_pid
, (caddr_t
)1, sig
);
150 thread
->attached
= 0;
154 if (sig
) kill( thread
->unix_pid
, sig
);
155 if (thread
->suspend
+ thread
->process
->suspend
) continue_thread( thread
);
159 /* stop a thread (at the Unix level) */
160 void stop_thread( struct thread
*thread
)
162 /* can't stop a thread while initialisation is in progress */
163 if (!thread
->unix_pid
|| thread
->process
->init_event
) return;
164 /* first try to attach to it */
165 if (!thread
->attached
)
166 if (attach_thread( thread
)) return; /* this will have stopped it */
167 /* attached already, or attach failed -> send a signal */
168 kill( thread
->unix_pid
, SIGSTOP
);
169 if (thread
->attached
) wait4_thread( thread
, SIGSTOP
);
172 /* make a thread continue (at the Unix level) */
173 void continue_thread( struct thread
*thread
)
175 if (!thread
->unix_pid
) return;
176 if (!thread
->attached
) kill( thread
->unix_pid
, SIGCONT
);
177 else ptrace( get_thread_single_step(thread
) ? PTRACE_SINGLESTEP
: PTRACE_CONT
,
178 thread
->unix_pid
, (caddr_t
)1, SIGSTOP
);
181 /* suspend a thread to allow using ptrace on it */
182 /* you must do a resume_thread when finished with the thread */
183 int suspend_for_ptrace( struct thread
*thread
)
185 if (thread
->attached
)
187 suspend_thread( thread
, 0 );
190 /* can't stop a thread while initialisation is in progress */
191 if (!thread
->unix_pid
|| thread
->process
->init_event
) goto error
;
193 if (attach_thread( thread
)) return 1;
196 set_error( STATUS_ACCESS_DENIED
);
200 /* read an int from a thread address space */
201 int read_thread_int( struct thread
*thread
, const int *addr
, int *data
)
203 *data
= ptrace( PTRACE_PEEKDATA
, thread
->unix_pid
, (caddr_t
)addr
, 0 );
204 if ( *data
== -1 && errno
)
212 /* write an int to a thread address space */
213 int write_thread_int( struct thread
*thread
, int *addr
, int data
, unsigned int mask
)
218 if (read_thread_int( thread
, addr
, &res
) == -1) return -1;
219 data
= (data
& mask
) | (res
& ~mask
);
221 if ((res
= ptrace( PTRACE_POKEDATA
, thread
->unix_pid
, (caddr_t
)addr
, data
)) == -1)