Merge branch 'fix/dw' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-dw

Conflicts:
	drivers/spi/spi-dw-mid.c

1 files changed, 12 insertions, 1 deletions

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 734e9a7d280b..3995f546d0f3 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1778,7 +1778,18 @@ static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs)
         unsigned long hash, flags = 0;
         struct kretprobe_instance *ri;
 
-        /*TODO: consider to only swap the RA after the last pre_handler fired */
+        /*
+         * To avoid deadlocks, prohibit return probing in NMI contexts,
+         * just skip the probe and increase the (inexact) 'nmissed'
+         * statistical counter, so that the user is informed that
+         * something happened:
+         */
+        if (unlikely(in_nmi())) {
+                rp->nmissed++;
+                return 0;
+        }
+
+        /* TODO: consider to only swap the RA after the last pre_handler fired */
         hash = hash_ptr(current, KPROBE_HASH_BITS);
         raw_spin_lock_irqsave(&rp->lock, flags);
         if (!hlist_empty(&rp->free_instances)) {