+ dma-debug-avoid-spinlock-recursion-when-disabling-dma-debug.patch added to -mm tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: dma-debug: avoid spinlock recursion when disabling dma-debug
has been added to the -mm tree.  Its filename is
     dma-debug-avoid-spinlock-recursion-when-disabling-dma-debug.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/dma-debug-avoid-spinlock-recursion-when-disabling-dma-debug.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/dma-debug-avoid-spinlock-recursion-when-disabling-dma-debug.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Subject: 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@xxxxxxxxxxxxxxx
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 lib/dma-debug.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN lib/dma-debug.c~dma-debug-avoid-spinlock-recursion-when-disabling-dma-debug lib/dma-debug.c
--- a/lib/dma-debug.c~dma-debug-avoid-spinlock-recursion-when-disabling-dma-debug
+++ a/lib/dma-debug.c
@@ -657,9 +657,9 @@ static struct dma_debug_entry *dma_entry
 	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;
 	}
 
_

Patches currently in -mm which might be from ville.syrjala@xxxxxxxxxxxxxxx are

dma-debug-avoid-spinlock-recursion-when-disabling-dma-debug.patch

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]