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    SubjectRe: [RFC] [PATCH 2.6.37-rc5-tip 5/20] 5: Uprobes: register/unregister probes.
    > > +
    > > + list_add(&mm->uprobes_list, &tmp_list);
    > > + mm->uprobes_vaddr = vma->vm_start + offset;
    > > + }
    > > + spin_unlock(&mapping->i_mmap_lock);
    >
    > Both this and unregister are racy, what is to say:
    > - the vma didn't get removed from the mm
    > - no new matching vma got added
    >

    register_uprobe, unregister_uprobe, uprobe_mmap are all synchronized by
    uprobes_mutex. So I dont see one unregister_uprobe getting thro when
    another register_uprobe is working with a vma.

    If I am missing something elementary, please explain a bit more.

    > > + if (list_empty(&tmp_list)) {
    > > + ret = 0;
    > > + goto consumers_add;
    > > + }
    > > + list_for_each_entry_safe(mm, tmpmm, &tmp_list, uprobes_list) {
    > > + if (!install_uprobe(mm, uprobe))
    > > + ret = 0;
    > > + list_del(&mm->uprobes_list);
    > > + mmput(mm);
    > > + }
    > > +
    > > +consumers_add:
    > > + add_consumer(uprobe, consumer);
    > > + mutex_unlock(&uprobes_mutex);
    > > + put_uprobe(uprobe);
    > > + return ret;
    > > +}
    > > +

    --
    Thanks and Regards
    Srikar


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