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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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