• Eric W. Biederman's avatar
    [PATCH] pidhash: kill switch_exec_pids · d73d6529
    Eric W. Biederman authored
    switch_exec_pids is only called from de_thread by way of exec, and it is
    only called when we are exec'ing from a non thread group leader.
    
    Currently switch_exec_pids gives the leader the pid of the thread and
    unhashes and rehashes all of the process groups.  The leader is already in
    the EXIT_DEAD state so no one cares about it's pids.  The only concern for
    the leader is that __unhash_process called from release_task will function
    correctly.  If we don't touch the leader at all we know that
    __unhash_process will work fine so there is no need to touch the leader.
    
    For the task becomming the thread group leader, we just need to give it the
    pid of the old thread group leader, add it to the task list, and attach it
    to the session and the process group of the thread group.
    
    Currently de_thread is also adding the task to the task list which is just
    silly.
    
    Currently the only leader of __detach_pid besides detach_pid is
    switch_exec_pids because of the ugly extra work that was being
    performed.
    
    So this patch removes switch_exec_pids because it is doing too much, it is
    creating an unnecessary special case in pid.c, duing work duplicated in
    de_thread, and generally obscuring what it is going on.
    
    The necessary work is added to de_thread, and it seems to be a little
    clearer there what is going on.
    Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
    Cc: Oleg Nesterov <oleg@tv-sign.ru>
    Cc: Kirill Korotaev <dev@sw.ru>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    d73d6529
pid.c 6.57 KB