Subject: linux-next: build failure after merge of the rcu tree

From: Stephen Rothwell <[email-masked]>
Date: Thu, 16 Jul 2015 13:14:23 +1000

Hi Paul,

After merging the rcu tree, today's linux-next build (arm
multi_v7_defconfig) failed like this:

kernel/notifier.c: In function 'notify_die':
kernel/notifier.c:547:2: error: implicit declaration of function 'rcu_lockdep_assert' [-Werror=implicit-function-declaration]
  rcu_lockdep_assert(rcu_is_watching(),
  ^

Caused by commit

  02300fdb3e5f ("rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN()")

interacting with commit

  e727c7d7a11e ("notifiers, RCU: Assert that RCU is watching in notify_die()")

[ and I also noted
  0333a209cbf6 ("x86/irq, context_tracking: Document how IRQ context tracking works and add an RCU assertion")
]

from the tip tree.

I added the following merge fix patch:

From: Stephen Rothwell <[email-masked]>
Date: Thu, 16 Jul 2015 13:08:50 +1000
Subject: [PATCH] rcu: merge fix for Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN()

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 arch/x86/kernel/irq.c | 2 +-
 kernel/notifier.c     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 30dbf35bc90b..f9cd81825187 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -234,7 +234,7 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 	entering_irq();
 
 	/* entering_irq() tells RCU that we're not quiescent.  Check it. */
-	rcu_lockdep_assert(rcu_is_watching(), "IRQ failed to wake up RCU");
+	RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU");
 
 	irq = __this_cpu_read(vector_irq[vector]);
 
diff --git a/kernel/notifier.c b/kernel/notifier.c
index 980e4330fb59..fd2c9acbcc19 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -544,7 +544,7 @@ int notrace notify_die(enum die_val val, const char *str,
 		.signr	= sig,
 
 	};
-	rcu_lockdep_assert(rcu_is_watching(),
+	RCU_LOCKDEP_WARN(!rcu_is_watching(),
 			   "notify_die called but RCU thinks we're quiescent");
 	return atomic_notifier_call_chain(&die_chain, val, &args);
 }
-- 
2.1.4

-- 
Cheers,
Stephen Rothwell                    [email-masked]