• Oleg Nesterov's avatar
    mm_for_maps: simplify, use ptrace_may_access() · 13f0feaf
    Oleg Nesterov authored
    It would be nice to kill __ptrace_may_access(). It requires task_lock(),
    but this lock is only needed to read mm->flags in the middle.
    Convert mm_for_maps() to use ptrace_may_access(), this also simplifies
    the code a little bit.
    Also, we do not need to take ->mmap_sem in advance. In fact I think
    mm_for_maps() should not play with ->mmap_sem at all, the caller should
    take this lock.
    With or without this patch, without ->cred_guard_mutex held we can race
    with exec() and get the new ->mm but check old creds.
    Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
    Reviewed-by: default avatarSerge Hallyn <serue@us.ibm.com>
    Signed-off-by: default avatarJames Morris <jmorris@namei.org>