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Commit 3017cd63 authored by Ville Syrjälä's avatar Ville Syrjälä Committed by Linus Torvalds
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dma-debug: avoid spinlock recursion when disabling dma-debug 

With netconsole (at least) the pr_err("...  disablingn") call can
recurse back into the dma-debug code, where it'll try to grab
free_entries_lock again.  Avoid the problem by doing the printk after
dropping the lock.

Link: http://lkml.kernel.org/r/1463678421-18683-1-git-send-email-ville.syrjala@linux.intel.com


Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7ef949d7

lib/dma-debug.c

+1 −1
Original line number Diff line number Diff line
@@ -657,9 +657,9 @@ static struct dma_debug_entry *dma_entry_alloc(void) 
	spin_lock_irqsave(&free_entries_lock, flags);



	if (list_empty(&free_entries)) {

		pr_err("DMA-API: debugging out of memory - disabling\n");

		global_disable = true;

		spin_unlock_irqrestore(&free_entries_lock, flags);

		pr_err("DMA-API: debugging out of memory - disabling\n");

		return NULL;

	}