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    SubjectRe: [PATCH] dma-debug: Fix deadlock with netconsole or other drivers that use the DMA API
    On Thu, Apr 19, 2012 at 11:48 AM, Andrew Morton
    <> wrote:
    > So *any* printk can deadlock if free_entries_lock is held and
    > global_disable==false?


    > In that case we're going to need much sterner fixes.  Any list_head
    > operation can do a printk if list_head debugging is enabled.
    > dma_debug_resize_entries() does a kfree() under free_entries_lock(!).
    > Methinks we need a more general fix?

    sigh... no good deed goes unpunished.

    OK, will look at it. Just to make things even more fun, all the
    err_printk() stuff can potentially deadlock on the hash bucket
    lock, although that requires enough bad luck a collision to happen.

    - R.
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