From: Jan Kratochvil <jan.kratochvil@redhat.com>
Date: Tue, 19 Nov 2013 14:04:14 +0000 (+0100)
Subject: Merge branch 'master' into portable
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b1a19549175f467b909e20c047c8775294f59645;p=thirdparty%2Felfutils.git

Merge branch 'master' into portable

Conflicts:
	libdwfl/linux-pid-attach.c
---

b1a19549175f467b909e20c047c8775294f59645
diff --cc libdwfl/linux-pid-attach.c
index fd2925010,e4eb62121..32eceb205
--- a/libdwfl/linux-pid-attach.c
+++ b/libdwfl/linux-pid-attach.c
@@@ -238,20 -238,12 +238,24 @@@ pid_thread_detach (Dwfl_Thread *thread
    pid_t tid = INTUSE(dwfl_thread_tid) (thread);
    assert (pid_arg->tid_attached == tid);
    pid_arg->tid_attached = 0;
-   if (! pid_arg->stopped)
-     {
-       ptrace (PTRACE_DETACH, tid, NULL, NULL);
-       return;
-     }
 +  // Older kernels (tested kernel-2.6.18-348.12.1.el5.x86_64) need special
 +  // handling of the detachment to keep the process State: T (stopped).
-   syscall (__NR_tkill, tid, SIGSTOP);
-   ptrace (PTRACE_DETACH, tid, NULL, (void *) (intptr_t) SIGSTOP);
-   // Wait till the SIGSTOP settles down.
-   int i;
-   for (i = 0; i < 100000; i++)
-     if (linux_proc_pid_is_stopped (tid))
-       break;
++  if (pid_arg->tid_was_stopped)
++    syscall (__NR_tkill, tid, SIGSTOP);
+   /* This handling is needed only on older Linux kernels such as
+      2.6.32-358.23.2.el6.ppc64.  Later kernels such as 3.11.7-200.fc19.x86_64
+      remember the T (stopped) state themselves and no longer need to pass
+      SIGSTOP during PTRACE_DETACH.  */
+   ptrace (PTRACE_DETACH, tid, NULL,
+ 	  (void *) (intptr_t) (pid_arg->tid_was_stopped ? SIGSTOP : 0));
++  if (pid_arg->tid_was_stopped)
++    {
++      // Wait till the SIGSTOP settles down.
++      int i;
++      for (i = 0; i < 100000; i++)
++	if (linux_proc_pid_is_stopped (tid))
++	  break;
++    }
  }
  
  static const Dwfl_Thread_Callbacks pid_thread_callbacks =