Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Conflicts:
	arch/x86/kernel/ptrace.c

Pull the latest RCU tree from Paul E. McKenney:

"       The major features of this series are:

  1.	A first version of no-callbacks CPUs.  This version prohibits
  	offlining CPU 0, but only when enabled via CONFIG_RCU_NOCB_CPU=y.
  	Relaxing this constraint is in progress, but not yet ready
  	for prime time.  These commits were posted to LKML at
  	https://lkml.org/lkml/2012/10/30/724, and are at branch rcu/nocb.

  2.	Changes to SRCU that allows statically initialized srcu_struct
  	structures.  These commits were posted to LKML at
  	https://lkml.org/lkml/2012/10/30/296, and are at branch rcu/srcu.

  3.	Restructuring of RCU's debugfs output.  These commits were posted
  	to LKML at https://lkml.org/lkml/2012/10/30/341, and are at
  	branch rcu/tracing.

  4.	Additional CPU-hotplug/RCU improvements, posted to LKML at
  	https://lkml.org/lkml/2012/10/30/327, and are at branch rcu/hotplug.
  	Note that the commit eliminating __stop_machine() was judged to
  	be too-high of risk, so is deferred to 3.9.

  5.	Changes to RCU's idle interface, most notably a new module
  	parameter that redirects normal grace-period operations to
  	their expedited equivalents.  These were posted to LKML at
  	https://lkml.org/lkml/2012/10/30/739, and are at branch rcu/idle.

  6.	Additional diagnostics for RCU's CPU stall warning facility,
  	posted to LKML at https://lkml.org/lkml/2012/10/30/315, and
  	are at branch rcu/stall.  The most notable change reduces the
  	default RCU CPU stall-warning time from 60 seconds to 21 seconds,
  	so that it once again happens sooner than the softlockup timeout.

  7.	Documentation updates, which were posted to LKML at
  	https://lkml.org/lkml/2012/10/30/280, and are at branch rcu/doc.
  	A couple of late-breaking changes were posted at
  	https://lkml.org/lkml/2012/11/16/634 and
  	https://lkml.org/lkml/2012/11/16/547.

  8.	Miscellaneous fixes, which were posted to LKML at
  	https://lkml.org/lkml/2012/10/30/309, along with a late-breaking
  	change posted at Fri, 16 Nov 2012 11:26:25 -0800 with message-ID
  	<20121116192625.GA447@linux.vnet.ibm.com>, but which lkml.org
  	seems to have missed.  These are at branch rcu/fixes.

  9.	Finally, a fix for an lockdep-RCU splat was posted to LKML
  	at https://lkml.org/lkml/2012/11/7/486.  This is at rcu/next. "

Signed-off-by: Ingo Molnar <mingo@kernel.org>

9 files changed, 27 insertions, 25 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index 366ec06a5185..cc74aaea116c 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -300,15 +300,16 @@ config SECCOMP_FILTER
 
 	  See Documentation/prctl/seccomp_filter.txt for details.
 
-config HAVE_RCU_USER_QS
+config HAVE_CONTEXT_TRACKING
 	bool
 	help
-	  Provide kernel entry/exit hooks necessary for userspace
-	  RCU extended quiescent state. Syscalls need to be wrapped inside
-	  rcu_user_exit()-rcu_user_enter() through the slow path using
-	  TIF_NOHZ flag. Exceptions handlers must be wrapped as well. Irqs
-	  are already protected inside rcu_irq_enter/rcu_irq_exit() but
-	  preemption or signal handling on irq exit still need to be protected.
+	  Provide kernel/user boundaries probes necessary for subsystems
+	  that need it, such as userspace RCU extended quiescent state.
+	  Syscalls need to be wrapped inside user_exit()-user_enter() through
+	  the slow path using TIF_NOHZ flag. Exceptions handlers must be
+	  wrapped as well. Irqs are already protected inside
+	  rcu_irq_enter/rcu_irq_exit() but preemption or signal handling on
+	  irq exit still need to be protected.
 
 config HAVE_VIRT_CPU_ACCOUNTING
 	bool
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 79ccfe6c7078..49e3b49e552f 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -648,7 +648,7 @@ static void stack_proc(void *arg)
 	struct task_struct *from = current, *to = arg;
 
 	to->thread.saved_task = from;
-	rcu_switch(from, to);
+	rcu_user_hooks_switch(from, to);
 	switch_to(from, to, from);
 }
 
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 46c3bff3ced2..110cfad24f26 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -106,7 +106,7 @@ config X86
 	select KTIME_SCALAR if X86_32
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
-	select HAVE_RCU_USER_QS if X86_64
+	select HAVE_CONTEXT_TRACKING if X86_64
 	select HAVE_IRQ_TIME_ACCOUNTING
 	select GENERIC_KERNEL_THREAD
 	select GENERIC_KERNEL_EXECVE
diff --git a/arch/x86/include/asm/rcu.h b/arch/x86/include/asm/context_tracking.h
index d1ac07a23979..1616562683e9 100644
--- a/arch/x86/include/asm/rcu.h
+++ b/arch/x86/include/asm/context_tracking.h
@@ -1,27 +1,26 @@
-#ifndef _ASM_X86_RCU_H
-#define _ASM_X86_RCU_H
+#ifndef _ASM_X86_CONTEXT_TRACKING_H
+#define _ASM_X86_CONTEXT_TRACKING_H
 
 #ifndef __ASSEMBLY__
-
-#include <linux/rcupdate.h>
+#include <linux/context_tracking.h>
 #include <asm/ptrace.h>
 
 static inline void exception_enter(struct pt_regs *regs)
 {
-	rcu_user_exit();
+	user_exit();
 }
 
 static inline void exception_exit(struct pt_regs *regs)
 {
-#ifdef CONFIG_RCU_USER_QS
+#ifdef CONFIG_CONTEXT_TRACKING
 	if (user_mode(regs))
-		rcu_user_enter();
+		user_enter();
 #endif
 }
 
 #else /* __ASSEMBLY__ */
 
-#ifdef CONFIG_RCU_USER_QS
+#ifdef CONFIG_CONTEXT_TRACKING
 # define SCHEDULE_USER call schedule_user
 #else
 # define SCHEDULE_USER call schedule
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 1328fe49a3f1..2a3806b95831 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -56,7 +56,7 @@
 #include <asm/ftrace.h>
 #include <asm/percpu.h>
 #include <asm/asm.h>
-#include <asm/rcu.h>
+#include <asm/context_tracking.h>
 #include <asm/smap.h>
 #include <linux/err.h>
 
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 974b67e46dd0..b629bbe0d9bd 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -23,6 +23,7 @@
 #include <linux/hw_breakpoint.h>
 #include <linux/rcupdate.h>
 #include <linux/module.h>
+#include <linux/context_tracking.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -1491,7 +1492,7 @@ long syscall_trace_enter(struct pt_regs *regs)
 {
 	long ret = 0;
 
-	rcu_user_exit();
+	user_exit();
 
 	/*
 	 * If we stepped into a sysenter/syscall insn, it trapped in
@@ -1546,7 +1547,7 @@ void syscall_trace_leave(struct pt_regs *regs)
 	 * or do_notify_resume(), in which case we can be in RCU
 	 * user mode.
 	 */
-	rcu_user_exit();
+	user_exit();
 
 	audit_syscall_exit(regs);
 
@@ -1564,5 +1565,5 @@ void syscall_trace_leave(struct pt_regs *regs)
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
 		tracehook_report_syscall_exit(regs, step);
 
-	rcu_user_enter();
+	user_enter();
 }
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 70b27ee6118e..fbbb604313a2 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -22,6 +22,7 @@
 #include <linux/uaccess.h>
 #include <linux/user-return-notifier.h>
 #include <linux/uprobes.h>
+#include <linux/context_tracking.h>
 
 #include <asm/processor.h>
 #include <asm/ucontext.h>
@@ -816,7 +817,7 @@ static void do_signal(struct pt_regs *regs)
 void
 do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
 {
-	rcu_user_exit();
+	user_exit();
 
 #ifdef CONFIG_X86_MCE
 	/* notify userspace of pending MCEs */
@@ -838,7 +839,7 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
 	if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)
 		fire_user_return_notifiers();
 
-	rcu_user_enter();
+	user_enter();
 }
 
 void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 8276dc6794cc..eb8586693e0b 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -55,7 +55,7 @@
 #include <asm/i387.h>
 #include <asm/fpu-internal.h>
 #include <asm/mce.h>
-#include <asm/rcu.h>
+#include <asm/context_tracking.h>
 
 #include <asm/mach_traps.h>
 
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 8e13ecb41bee..7a529cbab7ad 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -18,7 +18,7 @@
 #include <asm/pgalloc.h>		/* pgd_*(), ...			*/
 #include <asm/kmemcheck.h>		/* kmemcheck_*(), ...		*/
 #include <asm/fixmap.h>			/* VSYSCALL_START		*/
-#include <asm/rcu.h>			/* exception_enter(), ...	*/
+#include <asm/context_tracking.h>	/* exception_enter(), ...	*/
 
 /*
  * Page fault error code bits: