server: Use the standard suspend mechanism to simulate a breakpoint

server/context_alpha.c

@@ -321,17 +321,10 @@ static void copy_context( CONTEXT *to, const CONTEXT *from, unsigned int flags )
     to->ContextFlags |= flags;
 }
 
-/* retrieve the current instruction pointer of a thread */
-void *get_thread_ip( struct thread *thread )
+/* retrieve the current instruction pointer of a context */
+void *get_context_ip( const CONTEXT *context )
 {
-    CONTEXT context;
-    context.Fir = 0;
-    if (suspend_for_ptrace( thread ))
-    {
-        get_thread_context( thread, CONTEXT_CONTROL, &context );
-        resume_after_ptrace( thread );
-    }
-    return (void *)context.Fir;
+    return (void *)context->Fir;
 }
 
 /* retrieve the thread context */

server/context_i386.c

@@ -537,17 +537,10 @@ static void copy_context( CONTEXT *to, const CONTEXT *from, unsigned int flags )
     to->ContextFlags |= flags & ~CONTEXT_DEBUG_REGISTERS;
 }
 
-/* retrieve the current instruction pointer of a thread */
-void *get_thread_ip( struct thread *thread )
+/* retrieve the current instruction pointer of a context */
+void *get_context_ip( const CONTEXT *context )
 {
-    CONTEXT context;
-    context.Eip = 0;
-    if (suspend_for_ptrace( thread ))
-    {
-        get_thread_context_ptrace( thread, CONTEXT_CONTROL, &context );
-        resume_after_ptrace( thread );
-    }
-    return (void *)context.Eip;
+    return (void *)context->Eip;
 }
 
 /* retrieve the thread context */

server/context_powerpc.c

@@ -260,17 +260,10 @@ static void copy_context( CONTEXT *to, const CONTEXT *from, unsigned int flags )
     }
 }
 
-/* retrieve the current instruction pointer of a thread */
-void *get_thread_ip( struct thread *thread )
+/* retrieve the current instruction pointer of a context */
+void *get_context_ip( const CONTEXT *context )
 {
-    CONTEXT context;
-    context.Iar = 0;
-    if (suspend_for_ptrace( thread ))
-    {
-        get_thread_context_ptrace( thread, CONTEXT_CONTROL, &context );
-        resume_after_ptrace( thread );
-    }
-    return (void *)context.Iar;
+    return (void *)context->Iar;
 }
 
 /* retrieve the thread context */

server/context_sparc.c

@@ -159,17 +159,10 @@ static void copy_context( CONTEXT *to, const CONTEXT *from, unsigned int flags )
     context |= flags & (CONTEXT_CONTROL|CONTEXT_INTEGER);
 }
 
-/* retrieve the current instruction pointer of a thread */
-void *get_thread_ip( struct thread *thread )
+/* retrieve the current instruction pointer of a context */
+void *get_context_ip( const CONTEXT *context )
 {
-    CONTEXT context;
-    context.pc = 0;
-    if (suspend_for_ptrace( thread ))
-    {
-        get_thread_context_ptrace( thread, CONTEXT_CONTROL, &context );
-        resume_after_ptrace( thread );
-    }
-    return (void *)context.pc;
+    return (void *)context->pc;
 }
 
 /* retrieve the thread context */

server/context_x86_64.c

@@ -248,17 +248,10 @@ static void copy_context( CONTEXT *to, const CONTEXT *from, unsigned int flags )
     to->ContextFlags |= flags & ~CONTEXT_DEBUG_REGISTERS;
 }
 
-/* retrieve the current instruction pointer of a thread */
-void *get_thread_ip( struct thread *thread )
+/* retrieve the current instruction pointer of a context */
+void *get_context_ip( const CONTEXT *context )
 {
-    CONTEXT context;
-    context.Rip = 0;
-    if (suspend_for_ptrace( thread ))
-    {
-        get_thread_context_ptrace( thread, CONTEXT_CONTROL, &context );
-        resume_after_ptrace( thread );
-    }
-    return (void *)context.Rip;
+    return (void *)context->Rip;
 }
 
 /* retrieve the thread context */

server/debugger.c

@@ -616,19 +616,9 @@ DECL_HANDLER(debug_process)
     }
     else if (debugger_attach( process, current ))
     {
-        struct debug_event_exception data;
-        struct thread *thread = get_process_first_thread( process );
-
         generate_startup_debug_events( process, NULL );
+        break_process( process );
         resume_process( process );
-
-        data.record.ExceptionCode    = EXCEPTION_BREAKPOINT;
-        data.record.ExceptionFlags   = EXCEPTION_CONTINUABLE;
-        data.record.ExceptionRecord  = NULL;
-        data.record.ExceptionAddress = get_thread_ip( thread );
-        data.record.NumberParameters = 0;
-        data.first = 1;
-        generate_debug_event( thread, EXCEPTION_DEBUG_EVENT, &data );
     }
     release_object( process );
 }
@@ -704,22 +694,12 @@ DECL_HANDLER(debug_break)
     struct process *process;
 
     reply->self = 0;
-    if (!(process = get_process_from_handle( req->handle, PROCESS_SET_INFORMATION /*FIXME*/ )))
-        return;
-    if (process != current->process)
+    if ((process = get_process_from_handle( req->handle, PROCESS_SET_INFORMATION /*FIXME*/ )))
     {
-        /* find a suitable thread to signal */
-        struct thread *thread;
-        LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
-        {
-            if (send_thread_signal( thread, SIGTRAP )) goto done;
-        }
-        set_error( STATUS_ACCESS_DENIED );
+        if (process != current->process) break_process( process );
+        else reply->self = 1;
+        release_object( process );
     }
-    else reply->self = 1;
-
-done:
-    release_object( process );
 }
 
 /* set debugger kill on exit flag */

server/process.c

@@ -683,6 +683,28 @@ void kill_debugged_processes( struct thread *debugger, int exit_code )
 }
 
 
+/* trigger a breakpoint event in a given process */
+void break_process( struct process *process )
+{
+    struct thread *thread;
+
+    suspend_process( process );
+
+    LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
+    {
+        if (thread->context)  /* inside an exception event already */
+        {
+            break_thread( thread );
+            goto done;
+        }
+    }
+    if ((thread = get_process_first_thread( process ))) thread->debug_break = 1;
+    else set_error( STATUS_ACCESS_DENIED );
+done:
+    resume_process( process );
+}
+
+
 /* detach a debugger from all its debuggees */
 void detach_debugged_processes( struct thread *debugger )
 {

server/process.h

@@ -121,6 +121,7 @@ extern void kill_all_processes( struct process *skip, int exit_code );
 extern void kill_process( struct process *process, struct thread *skip, int exit_code );
 extern void kill_console_processes( struct thread *renderer, int exit_code );
 extern void kill_debugged_processes( struct thread *debugger, int exit_code );
+extern void break_process( struct process *process );
 extern void detach_debugged_processes( struct thread *debugger );
 extern struct process_snapshot *process_snap( int *count );
 extern struct module_snapshot *module_snap( struct process *process, int *count );

server/thread.c

@@ -128,6 +128,7 @@ inline static void init_thread_structure( struct thread *thread )
     thread->teb             = NULL;
     thread->debug_ctx       = NULL;
     thread->debug_event     = NULL;
+    thread->debug_break     = 0;
     thread->queue           = NULL;
     thread->wait            = NULL;
     thread->error           = 0;
@@ -759,6 +760,23 @@ void kill_thread( struct thread *thread, int violent_death )
     release_object( thread );
 }
 
+/* trigger a breakpoint event in a given thread */
+void break_thread( struct thread *thread )
+{
+    struct debug_event_exception data;
+
+    assert( thread->context );
+
+    data.record.ExceptionCode    = EXCEPTION_BREAKPOINT;
+    data.record.ExceptionFlags   = EXCEPTION_CONTINUABLE;
+    data.record.ExceptionRecord  = NULL;
+    data.record.ExceptionAddress = get_context_ip( thread->context );
+    data.record.NumberParameters = 0;
+    data.first = 1;
+    generate_debug_event( thread, EXCEPTION_DEBUG_EVENT, &data );
+    thread->debug_break = 0;
+}
+
 /* take a snapshot of currently running threads */
 struct thread_snapshot *thread_snap( int *count )
 {
@@ -1091,6 +1109,7 @@ DECL_HANDLER(set_thread_context)
         {
             memcpy( thread->suspend_context, get_req_data(), sizeof(CONTEXT) );
             thread->context = thread->suspend_context;
+            if (thread->debug_break) break_thread( thread );
         }
     }
     else if (thread != current && !thread->context)

server/thread.h

@@ -56,6 +56,7 @@ struct thread
     struct list            mutex_list;    /* list of currently owned mutexes */
     struct debug_ctx      *debug_ctx;     /* debugger context if this thread is a debugger */
     struct debug_event    *debug_event;   /* debug event being sent to debugger */
+    int                    debug_break;   /* debug breakpoint pending? */
     struct msg_queue      *queue;         /* message queue */
     struct thread_wait    *wait;          /* current wait condition if sleeping */
     struct list            system_apc;    /* queue of system async procedure calls */
@@ -108,6 +109,7 @@ extern int wake_thread( struct thread *thread );
 extern int add_queue( struct object *obj, struct wait_queue_entry *entry );
 extern void remove_queue( struct object *obj, struct wait_queue_entry *entry );
 extern void kill_thread( struct thread *thread, int violent_death );
+extern void break_thread( struct thread *thread );
 extern void wake_up( struct object *obj, int max );
 extern int thread_queue_apc( struct thread *thread, struct object *owner, void *func,
                              enum apc_type type, int system, void *arg1, void *arg2, void *arg3 );
@@ -123,7 +125,7 @@ extern void sigchld_callback(void);
 extern int get_ptrace_pid( struct thread *thread );
 extern int suspend_for_ptrace( struct thread *thread );
 extern void resume_after_ptrace( struct thread *thread );
-extern void *get_thread_ip( struct thread *thread );
+extern void *get_context_ip( const CONTEXT *context );
 extern void get_thread_context( struct thread *thread, CONTEXT *context, unsigned int flags );
 extern void set_thread_context( struct thread *thread, const CONTEXT *context, unsigned int flags );
 extern int send_thread_signal( struct thread *thread, int sig );