Added send_thread_signal() function and properly handle errors caused
by the thread having already died when we send it a signal.
Use -1 instead of 0 as invalid Unix pid value.
diff --git a/server/ptrace.c b/server/ptrace.c
index 2c0c12b..b83ab7d 100644
--- a/server/ptrace.c
+++ b/server/ptrace.c
@@ -93,7 +93,7 @@
if (thread && (WIFSIGNALED(status) || WIFEXITED(status)))
{
thread->attached = 0;
- thread->unix_pid = 0;
+ thread->unix_pid = -1;
if (debug_level)
{
if (WIFSIGNALED(status))
@@ -136,6 +136,23 @@
} 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 )
{
@@ -143,7 +160,7 @@
if (!use_ptrace) return 0;
if (ptrace( PTRACE_ATTACH, thread->unix_pid, 0, 0 ) == -1)
{
- if (errno == ESRCH) thread->unix_pid = 0; /* process got killed */
+ if (errno == ESRCH) thread->unix_pid = -1; /* thread got killed */
return 0;
}
if (debug_level) fprintf( stderr, "%04x: *attached*\n", thread->id );
@@ -155,12 +172,13 @@
/* detach from a Unix thread and kill it */
void detach_thread( struct thread *thread, int sig )
{
- if (!thread->unix_pid) return;
+ if (thread->unix_pid == -1) return;
if (thread->attached)
{
/* make sure it is stopped */
suspend_thread( thread, 0 );
- if (sig) kill( thread->unix_pid, sig );
+ 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->suspend = 0; /* detach makes it continue */
@@ -168,7 +186,7 @@
}
else
{
- if (sig) kill( thread->unix_pid, sig );
+ if (sig) send_thread_signal( thread, sig );
if (thread->suspend + thread->process->suspend) continue_thread( thread );
}
}
@@ -177,21 +195,21 @@
void stop_thread( struct thread *thread )
{
/* can't stop a thread while initialisation is in progress */
- if (!thread->unix_pid || !is_process_init_done(thread->process)) return;
+ if (thread->unix_pid == -1 || !is_process_init_done(thread->process)) return;
/* first try to attach to it */
if (!thread->attached)
if (attach_thread( thread )) return; /* this will have stopped it */
/* attached already, or attach failed -> send a signal */
- if (!thread->unix_pid) return;
- kill( thread->unix_pid, SIGSTOP );
+ if (thread->unix_pid == -1) return;
+ send_thread_signal( thread, SIGSTOP );
if (thread->attached) wait4_thread( thread, SIGSTOP );
}
/* make a thread continue (at the Unix level) */
void continue_thread( struct thread *thread )
{
- if (!thread->unix_pid) return;
- if (!thread->attached) kill( thread->unix_pid, SIGCONT );
+ if (thread->unix_pid == -1) return;
+ if (!thread->attached) send_thread_signal( thread, SIGCONT );
else ptrace( get_thread_single_step(thread) ? PTRACE_SINGLESTEP : PTRACE_CONT,
thread->unix_pid, (caddr_t)1, SIGSTOP );
}
@@ -206,7 +224,7 @@
return 1;
}
/* can't stop a thread while initialisation is in progress */
- if (!thread->unix_pid || !is_process_init_done(thread->process)) goto error;
+ if (thread->unix_pid == -1 || !is_process_init_done(thread->process)) goto error;
thread->suspend++;
if (attach_thread( thread )) return 1;
thread->suspend--;
