[PATCH] fix non-leader exec under ptrace

This reverts most of commit 30e0fca6c1d7d26f3f2daa4dd2b12c51dadc778a.
It broke the case of non-leader MT exec when ptraced.
I think the bug it was intended to fix was already addressed by commit
788e05a67c343fa22f2ae1d3ca264e7f15c25eaf.

Signed-off-by: Roland McGrath <roland@redhat.com>
Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 4 insertions, 7 deletions

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 0eeb7e66722c..4e0f0ec003f7 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -56,10 +56,6 @@ void ptrace_untrace(task_t *child)
                         signal_wake_up(child, 1);
                 }
         }
-        if (child->signal->flags & SIGNAL_GROUP_EXIT) {
-                sigaddset(&child->pending.signal, SIGKILL);
-                signal_wake_up(child, 1);
-        }
         spin_unlock(&child->sighand->siglock);
 }
 
@@ -81,7 +77,8 @@ void __ptrace_unlink(task_t *child)
                 add_parent(child);
         }
 
-        ptrace_untrace(child);
+        if (child->state == TASK_TRACED)
+                ptrace_untrace(child);
 }
 
 /*
diff --git a/kernel/signal.c b/kernel/signal.c
index b14f895027c3..e5f8aea78ffe 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1754,9 +1754,9 @@ relock:
                         /* Let the debugger run.  */
                         ptrace_stop(signr, signr, info);
 
-                        /* We're back.  Did the debugger cancel the sig or group_exit? */
+                        /* We're back.  Did the debugger cancel the sig?  */
                         signr = current->exit_code;
-                        if (signr == 0 || current->signal->flags & SIGNAL_GROUP_EXIT)
+                        if (signr == 0)
                                 continue;
 
                         current->exit_code = 0;