hung_task: fix false positive during vfork
[linux-2.6.git] / kernel / ptrace.c
index d7ccc79..a70d2a5 100644 (file)
@@ -23,6 +23,7 @@
 #include <linux/uaccess.h>
 #include <linux/regset.h>
 #include <linux/hw_breakpoint.h>
+#include <linux/cn_proc.h>
 
 
 static int ptrace_trapping_sleep_fn(void *flags)
@@ -305,9 +306,12 @@ unlock_tasklist:
 unlock_creds:
        mutex_unlock(&task->signal->cred_guard_mutex);
 out:
-       if (!retval)
+       if (!retval) {
                wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
                            ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE);
+               proc_ptrace_connector(task, PTRACE_ATTACH);
+       }
+
        return retval;
 }
 
@@ -415,6 +419,7 @@ static int ptrace_detach(struct task_struct *child, unsigned int data)
        }
        write_unlock_irq(&tasklist_lock);
 
+       proc_ptrace_connector(child, PTRACE_DETACH);
        if (unlikely(dead))
                release_task(child);
 
@@ -739,20 +744,17 @@ int ptrace_request(struct task_struct *child, long request,
                        break;
 
                si = child->last_siginfo;
-               if (unlikely(!si || si->si_code >> 8 != PTRACE_EVENT_STOP))
-                       break;
-
-               child->jobctl |= JOBCTL_LISTENING;
-
-               /*
-                * If NOTIFY is set, it means event happened between start
-                * of this trap and now.  Trigger re-trap immediately.
-                */
-               if (child->jobctl & JOBCTL_TRAP_NOTIFY)
-                       signal_wake_up(child, true);
-
+               if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
+                       child->jobctl |= JOBCTL_LISTENING;
+                       /*
+                        * If NOTIFY is set, it means event happened between
+                        * start of this trap and now.  Trigger re-trap.
+                        */
+                       if (child->jobctl & JOBCTL_TRAP_NOTIFY)
+                               signal_wake_up(child, true);
+                       ret = 0;
+               }
                unlock_task_sighand(child, &flags);
-               ret = 0;
                break;
 
        case PTRACE_DETACH:      /* detach a process that was attached. */