On 03/01, Bernd Edlinger wrote: > > This fixes a deadlock in the tracer when tracing a multi-threaded > application that calls execve while more than one thread are running. Heh. Yes, known problem. See my attempt to fix it: https://lore.kernel.org/lkml/20170213141452.GA30203@xxxxxxxxxx/ > @@ -1224,7 +1224,7 @@ struct mm_struct *mm_access(struct task_struct *task, unsigned int mode) > struct mm_struct *mm; > int err; > > - err = mutex_lock_killable(&task->signal->cred_guard_mutex); > + err = mutex_lock_killable(&task->signal->cred_change_mutex); So if I understand correctly your patch doesn't fix other problems with debugger waiting for cred_guard_mutex. I too do not think this can justify the new mutex in signal_struct... Oleg.