Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Conflicts:
	drivers/net/ethernet/emulex/benet/be_main.c
	drivers/net/ethernet/intel/igb/igb_main.c
	drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
	include/net/scm.h
	net/batman-adv/routing.c
	net/ipv4/tcp_input.c

The e{uid,gid} --> {uid,gid} credentials fix conflicted with the
cleanup in net-next to now pass cred structs around.

The be2net driver had a bug fix in 'net' that overlapped with the VLAN
interface changes by Patrick McHardy in net-next.

An IGB conflict existed because in 'net' the build_skb() support was
reverted, and in 'net-next' there was a comment style fix within that
code.

Several batman-adv conflicts were resolved by making sure that all
calls to batadv_is_my_mac() are changed to have a new bat_priv first
argument.

Eric Dumazet's TS ECR fix in TCP in 'net' conflicted with the F-RTO
rewrite in 'net-next', mostly overlapping changes.

Thanks to Stephen Rothwell and Antonio Quartulli for help with several
of these merge resolutions.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 11 deletions

diff --git a/include/linux/spinlock_up.h b/include/linux/spinlock_up.h
index a26e2fb604e..e2369c167db 100644
--- a/include/linux/spinlock_up.h
+++ b/include/linux/spinlock_up.h
@@ -16,7 +16,10 @@
  * In the debug case, 1 means unlocked, 0 means locked. (the values
  * are inverted, to catch initialization bugs)
  *
- * No atomicity anywhere, we are on UP.
+ * No atomicity anywhere, we are on UP. However, we still need
+ * the compiler barriers, because we do not want the compiler to
+ * move potentially faulting instructions (notably user accesses)
+ * into the locked sequence, resulting in non-atomic execution.
  */
 
 #ifdef CONFIG_DEBUG_SPINLOCK
@@ -25,6 +28,7 @@
 static inline void arch_spin_lock(arch_spinlock_t *lock)
 {
 	lock->slock = 0;
+	barrier();
 }
 
 static inline void
@@ -32,6 +36,7 @@ arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
 {
 	local_irq_save(flags);
 	lock->slock = 0;
+	barrier();
 }
 
 static inline int arch_spin_trylock(arch_spinlock_t *lock)
@@ -39,32 +44,34 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock)
 	char oldval = lock->slock;
 
 	lock->slock = 0;
+	barrier();
 
 	return oldval > 0;
 }
 
 static inline void arch_spin_unlock(arch_spinlock_t *lock)
 {
+	barrier();
 	lock->slock = 1;
 }
 
 /*
  * Read-write spinlocks. No debug version.
  */
-#define arch_read_lock(lock)		do { (void)(lock); } while (0)
-#define arch_write_lock(lock)		do { (void)(lock); } while (0)
-#define arch_read_trylock(lock)	({ (void)(lock); 1; })
-#define arch_write_trylock(lock)	({ (void)(lock); 1; })
-#define arch_read_unlock(lock)		do { (void)(lock); } while (0)
-#define arch_write_unlock(lock)	do { (void)(lock); } while (0)
+#define arch_read_lock(lock)		do { barrier(); (void)(lock); } while (0)
+#define arch_write_lock(lock)		do { barrier(); (void)(lock); } while (0)
+#define arch_read_trylock(lock)	({ barrier(); (void)(lock); 1; })
+#define arch_write_trylock(lock)	({ barrier(); (void)(lock); 1; })
+#define arch_read_unlock(lock)		do { barrier(); (void)(lock); } while (0)
+#define arch_write_unlock(lock)	do { barrier(); (void)(lock); } while (0)
 
 #else /* DEBUG_SPINLOCK */
 #define arch_spin_is_locked(lock)	((void)(lock), 0)
 /* for sched.c and kernel_lock.c: */
-# define arch_spin_lock(lock)		do { (void)(lock); } while (0)
-# define arch_spin_lock_flags(lock, flags)	do { (void)(lock); } while (0)
-# define arch_spin_unlock(lock)	do { (void)(lock); } while (0)
-# define arch_spin_trylock(lock)	({ (void)(lock); 1; })
+# define arch_spin_lock(lock)		do { barrier(); (void)(lock); } while (0)
+# define arch_spin_lock_flags(lock, flags)	do { barrier(); (void)(lock); } while (0)
+# define arch_spin_unlock(lock)	do { barrier(); (void)(lock); } while (0)
+# define arch_spin_trylock(lock)	({ barrier(); (void)(lock); 1; })
 #endif /* DEBUG_SPINLOCK */
 
 #define arch_spin_is_contended(lock)	(((void)(lock), 0))