Re: [PATCH 1/3] uprobes: install_breakpoint() should fail ifis_swbp_insn() == T

From: Oleg Nesterov
Date: Fri Jun 01 2012 - 11:55:32 EST


On 05/31, Oleg Nesterov wrote:
>
> __find_next_vma_info() checks tmpvi->mm == vma->vm_mm to detect the
> already visited mm/vma. However, afaics this can be false positive?

Yes, but I guess this is harmless, we can rely on uprobe_mmap.



But. Doesn't this mean we can greatly simplify register_for_each_vma()
and make it O(n) ?

Unless I missed something, we can simply create the list of
mm/vaddr structures under ->i_mmap_mutex (vma_prio_tree_foreach), then
register_for_each_vma() can process the list and that is all.

If another mapping comes after we drop i_mmap_mutex, uprobe_mmap()
should be called and it should install the bp.


Srikar, Peter, what do you think?

Oleg.

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