Merge tag 'v4.9.185' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable into odroidn2-4.9.y

This is the 4.9.185 stable release

include/asm-generic/bug.h

@@ -47,6 +47,7 @@ struct bug_entry {
 #ifndef HAVE_ARCH_BUG
 #define BUG() do { \
 	printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
+	barrier_before_unreachable(); \
 	panic("BUG!"); \
 } while (0)
 #endif

include/linux/compiler-gcc.h

@@ -232,6 +232,15 @@
 #define annotate_unreachable()
 #endif
 
+/*
+ * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
+ * confuse the stack allocation in gcc, leading to overly large stack
+ * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
+ *
+ * Adding an empty inline assembly before it works around the problem
+ */
+#define barrier_before_unreachable() asm volatile("")
+
 /*
  * Mark a position in code as unreachable.  This can be used to
  * suppress control flow warnings after asm blocks that transfer
@@ -242,7 +251,11 @@
  * unreleased.  Really, we need to have autoconf for the kernel.
  */
 #define unreachable() \
-	do { annotate_unreachable(); __builtin_unreachable(); } while (0)
+	do {					\
+		annotate_unreachable();		\
+		barrier_before_unreachable();	\
+		__builtin_unreachable();	\
+	} while (0)
 
 /* Mark a function definition as prohibited from being cloned. */
 #define __noclone	__attribute__((__noclone__, __optimize__("no-tracer")))

include/linux/compiler.h

@@ -177,6 +177,11 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
 # define barrier_data(ptr) barrier()
 #endif
 
+/* workaround for GCC PR82365 if needed */
+#ifndef barrier_before_unreachable
+# define barrier_before_unreachable() do { } while (0)
+#endif
+
 /* Unreachable code */
 #ifndef unreachable
 # define unreachable() do { } while (1)

include/net/bluetooth/hci_core.h

@@ -176,6 +176,9 @@ struct adv_info {
 
 #define HCI_MAX_SHORT_NAME_LENGTH	10
 
+/* Min encryption key size to match with SMP */
+#define HCI_MIN_ENC_KEY_SIZE		7
+
 /* Default LE RPA expiry time, 15 minutes */
 #define HCI_DEFAULT_RPA_TIMEOUT		(15 * 60)