[PATCH] alpha: single-step breakpoints - updated fix

Restore 2.4 behavior when setting the single step breakpoints.

arch/alpha/kernel/ptrace.c

@@ -366,8 +366,8 @@ do_sys_ptrace(long request, long pid, long addr, long data,
 		ret = -EIO;
 		if ((unsigned long) data > _NSIG)
 			break;
-		/* Set single stepping.  */
-		ptrace_set_bpt(child);
+		/* Mark single stepping.  */
+		child->thread_info->bpt_nsaved = -1;
 		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 		wake_up_process(child);
 		child->exit_code = data;

arch/alpha/kernel/signal.c

@@ -619,7 +619,10 @@ do_signal(sigset_t *oldset, struct pt_regs * regs, struct switch_stack * sw,
 	if (!oldset)
 		oldset = &current->blocked;
 
+	/* This lets the debugger run, ... */
 	signr = get_signal_to_deliver(&info, regs, NULL);
+	/* ... so re-check the single stepping. */
+	single_stepping |= ptrace_cancel_bpt(current);
 
 	if (signr > 0) {
 		/* Whee!  Actually deliver the signal.  */