Messages in this thread Patch in this message | | | Date | Sun, 8 Feb 2009 19:47:30 +0100 | From | Oleg Nesterov <> | Subject | [PATCH 3/3] ptrace_untrace: fix the SIGNAL_STOP_STOPPED check |
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This bug is ancient too. ptrace_untrace() must not resume the task if the group stop in progress, we should set TASK_STOPPED instead.
Unfortunately, we still have problems here:
- if the process/thread was traced, SIGNAL_STOP_STOPPED does not necessary means this thread group is stopped.
- ptrace breaks the bookkeeping of ->group_stop_count.
(the comment above ptrace_untrace() doesn't look exactly right too).
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
--- 6.29-rc3/kernel/ptrace.c~3_FIX_STOPPED 2009-02-08 06:22:26.000000000 +0100 +++ 6.29-rc3/kernel/ptrace.c 2009-02-08 08:52:14.000000000 +0100 @@ -60,7 +60,8 @@ static void ptrace_untrace(struct task_s { spin_lock(&child->sighand->siglock); if (task_is_traced(child)) { - if (child->signal->flags & SIGNAL_STOP_STOPPED) + if (child->signal->flags & SIGNAL_STOP_STOPPED || + child->signal->group_stop_count) __set_task_state(child, TASK_STOPPED); else wake_up_process(child);
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