• O
    [PATCH] fix kill_proc_info() vs CLONE_THREAD race · 3f17da69
    Oleg Nesterov 提交于
    There is a window after copy_process() unlocks ->sighand.siglock
    and before it adds the new thread to the thread list.
    
    In that window __group_complete_signal(SIGKILL) will not see the
    new thread yet, so this thread will start running while the whole
    thread group was supposed to exit.
    
    I beleive we have another good reason to place attach_pid(PID/TGID)
    under ->sighand.siglock. We can do the same for
    
    	release_task()->__unhash_process()
    
    	de_thread()->switch_exec_pids()
    
    After that we don't need tasklist_lock to iterate over the thread
    list, and we can simplify things, see for example do_sigaction()
    or sys_times().
    Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
    Cc: Roland McGrath <roland@redhat.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
    3f17da69
fork.c 38.5 KB