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: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ville Syrjälä 2016-05-26 15:16:25 -07:00 committed by Linus Torvalds
parent 7ef949d77f
commit 3017cd63f2

View file

@ -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;
}