Messages in this thread | | | Subject | Re: [RFC] [PATCH 2.6.37-rc5-tip 5/20] 5: Uprobes: register/unregister probes. | From | Peter Zijlstra <> | Date | Wed, 26 Jan 2011 11:11:48 +0100 |
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On Wed, 2011-01-26 at 13:25 +0530, Srikar Dronamraju wrote: > > > > + > > > + 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.
afaict you're not holding the mmap_sem, so userspace can simply unmap the vma.
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