From 3017cd63f26fc655d56875aaf497153ba60e9edf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Thu, 26 May 2016 15:16:25 -0700 Subject: [PATCH] dma-debug: avoid spinlock recursion when disabling dma-debug MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/dma-debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 4a1515f4b452..51a76af25c66 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -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; }