Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - the rest of MM

 - KASAN updates

 - procfs updates

 - exit, fork updates

 - printk updates

 - lib/ updates

 - radix-tree testsuite updates

 - checkpatch updates

 - kprobes updates

 - a few other misc bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
  samples/kprobes: print out the symbol name for the hooks
  samples/kprobes: add a new module parameter
  kprobes: add the "tls" argument for j_do_fork
  init/main.c: simplify initcall_blacklisted()
  fs/efs/super.c: fix return value
  checkpatch: improve --git <commit-count> shortcut
  checkpatch: reduce number of `git log` calls with --git
  checkpatch: add support to check already applied git commits
  checkpatch: add --list-types to show message types to show or ignore
  checkpatch: advertise the --fix and --fix-inplace options more
  checkpatch: whine about ACCESS_ONCE
  checkpatch: add test for keywords not starting on tabstops
  checkpatch: improve CONSTANT_COMPARISON test for structure members
  checkpatch: add PREFER_IS_ENABLED test
  lib/GCD.c: use binary GCD algorithm instead of Euclidean
  radix-tree: free up the bottom bit of exceptional entries for reuse
  dax: move RADIX_DAX_ definitions to dax.c
  radix-tree: make radix_tree_descend() more useful
  radix-tree: introduce radix_tree_replace_clear_tags()
  radix-tree: tidy up __radix_tree_create()
  ...

70 files changed, 127 insertions, 189 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index 81869a5e7e17..b16e74e4b5af 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -187,7 +187,11 @@ config HAVE_OPTPROBES
 config HAVE_KPROBES_ON_FTRACE
 	bool
 
+config HAVE_NMI
+	bool
+
 config HAVE_NMI_WATCHDOG
+	depends on HAVE_NMI
 	bool
 #
 # An arch should select this if it provides all these things:
@@ -517,6 +521,11 @@ config HAVE_ARCH_MMAP_RND_BITS
 	  - ARCH_MMAP_RND_BITS_MIN
 	  - ARCH_MMAP_RND_BITS_MAX
 
+config HAVE_EXIT_THREAD
+	bool
+	help
+	  An architecture implements exit_thread.
+
 config ARCH_MMAP_RND_BITS_MIN
 	int
 
@@ -638,4 +647,7 @@ config COMPAT_OLD_SIGACTION
 config ARCH_NO_COHERENT_DMA_MMAP
 	bool
 
+config CPU_NO_EFFICIENT_FFS
+	def_bool n
+
 source "kernel/gcov/Kconfig"
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index fe99f894e57d..7f312d80b43b 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -26,6 +26,7 @@ config ALPHA
 	select MODULES_USE_ELF_RELA
 	select ODD_RT_SIGACTION
 	select OLD_SIGSUSPEND
+	select CPU_NO_EFFICIENT_FFS if !ALPHA_EV67
 	help
 	  The Alpha is a 64-bit general-purpose processor designed and
 	  marketed by the Digital Equipment Corporation of blessed memory,
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 84d13263ce46..b483156698d5 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -210,14 +210,6 @@ start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
 }
 EXPORT_SYMBOL(start_thread);
 
-/*
- * Free current thread data structures etc..
- */
-void
-exit_thread(void)
-{
-}
-
 void
 flush_thread(void)
 {
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 8894f7e7e3de..0dcbacfdea4b 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -107,6 +107,7 @@ choice
 
 config ISA_ARCOMPACT
 	bool "ARCompact ISA"
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  The original ARC ISA of ARC600/700 cores
 
diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
index a3f750e76b68..b5db9e7fd649 100644
--- a/arch/arc/kernel/process.c
+++ b/arch/arc/kernel/process.c
@@ -183,13 +183,6 @@ void flush_thread(void)
 {
 }
 
-/*
- * Free any architecture-specific thread data structures, etc.
- */
-void exit_thread(void)
-{
-}
-
 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 {
 	return 0;
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b99d25b4133e..90542db1220d 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -50,6 +50,7 @@ config ARM
 	select HAVE_DMA_CONTIGUOUS if MMU
 	select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 && MMU
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
+	select HAVE_EXIT_THREAD
 	select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL)
 	select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL)
 	select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
@@ -66,6 +67,7 @@ config ARM
 	select HAVE_KRETPROBES if (HAVE_KPROBES)
 	select HAVE_MEMBLOCK
 	select HAVE_MOD_ARCH_SPECIFIC
+	select HAVE_NMI
 	select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
 	select HAVE_OPTPROBES if !THUMB2_KERNEL
 	select HAVE_PERF_EVENTS
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 4adfb46e3ee9..a647d6642f3e 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -193,9 +193,9 @@ EXPORT_SYMBOL_GPL(thread_notify_head);
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
+	thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk));
 }
 
 void flush_thread(void)
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index baee70267f29..df90bc59bfce 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -644,9 +644,11 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
 		break;
 
 	case IPI_CPU_BACKTRACE:
+		printk_nmi_enter();
 		irq_enter();
 		nmi_cpu_backtrace(regs);
 		irq_exit();
+		printk_nmi_exit();
 		break;
 
 	default:
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 55347662e5ed..cb569b65a54d 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -421,18 +421,21 @@ config CPU_32v3
 	select CPU_USE_DOMAINS if MMU
 	select NEED_KUSER_HELPERS
 	select TLS_REG_EMUL if SMP || !MMU
+	select CPU_NO_EFFICIENT_FFS
 
 config CPU_32v4
 	bool
 	select CPU_USE_DOMAINS if MMU
 	select NEED_KUSER_HELPERS
 	select TLS_REG_EMUL if SMP || !MMU
+	select CPU_NO_EFFICIENT_FFS
 
 config CPU_32v4T
 	bool
 	select CPU_USE_DOMAINS if MMU
 	select NEED_KUSER_HELPERS
 	select TLS_REG_EMUL if SMP || !MMU
+	select CPU_NO_EFFICIENT_FFS
 
 config CPU_32v5
 	bool
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 2a61e4b04600..73085d3482ed 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -156,10 +156,6 @@ static void vfp_thread_copy(struct thread_info *thread)
  *   - we could be preempted if tree preempt rcu is enabled, so
  *	it is unsafe to use thread->cpu.
  *  THREAD_NOTIFY_EXIT
- *   - the thread (v) will be running on the local CPU, so
- *	v === current_thread_info()
- *   - thread->cpu is the local CPU number at the time it is accessed,
- *	but may change at any time.
  *   - we could be preempted if tree preempt rcu is enabled, so
  *	it is unsafe to use thread->cpu.
  */
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 48eea6866c67..6cd2612236dc 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -200,13 +200,6 @@ void show_regs(struct pt_regs * regs)
 	__show_regs(regs);
 }
 
-/*
- * Free current thread data structures etc..
- */
-void exit_thread(void)
-{
-}
-
 static void tls_thread_flush(void)
 {
 	asm ("msr tpidr_el0, xzr");
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index 18b88779e701..7e75d45e20cd 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -4,6 +4,7 @@ config AVR32
 	# that we usually don't need on AVR32.
 	select EXPERT
 	select HAVE_CLK
+	select HAVE_EXIT_THREAD
 	select HAVE_OPROFILE
 	select HAVE_KPROBES
 	select VIRT_TO_BUS
@@ -17,6 +18,7 @@ config AVR32
 	select GENERIC_CLOCKEVENTS
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
+	select HAVE_NMI
 	help
 	  AVR32 is a high-performance 32-bit RISC microprocessor core,
 	  designed for cost-sensitive embedded applications, with particular
diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c
index 42a53e740a7e..68e5b9dac059 100644
--- a/arch/avr32/kernel/process.c
+++ b/arch/avr32/kernel/process.c
@@ -62,9 +62,9 @@ void machine_restart(char *cmd)
 /*
  * Free current thread data structures etc
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	ocd_disable(current);
+	ocd_disable(tsk);
 }
 
 void flush_thread(void)
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index a63c12259e77..28c63fea786d 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -40,6 +40,7 @@ config BLACKFIN
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
 	select HAVE_DEBUG_STACKOVERFLOW
+	select HAVE_NMI
 
 config GENERIC_CSUM
 	def_bool y
diff --git a/arch/blackfin/include/asm/processor.h b/arch/blackfin/include/asm/processor.h
index 7acd46653df3..0c265aba94ad 100644
--- a/arch/blackfin/include/asm/processor.h
+++ b/arch/blackfin/include/asm/processor.h
@@ -76,13 +76,6 @@ static inline void release_thread(struct task_struct *dead_task)
 }
 
 /*
- * Free current thread data structures etc..
- */
-static inline void exit_thread(void)
-{
-}
-
-/*
  * Return saved PC of a blocked thread.
  */
 #define thread_saved_pc(tsk)	(tsk->thread.pc)
diff --git a/arch/c6x/kernel/process.c b/arch/c6x/kernel/process.c
index 3ae9f5a166a0..0ee7686a78f3 100644
--- a/arch/c6x/kernel/process.c
+++ b/arch/c6x/kernel/process.c
@@ -82,10 +82,6 @@ void flush_thread(void)
 {
 }
 
-void exit_thread(void)
-{
-}
-
 /*
  * Do necessary setup to start up a newly executed thread.
  */
diff --git a/arch/cris/Kconfig b/arch/cris/Kconfig
index 99bda1ba3d2f..deba2662b9f3 100644
--- a/arch/cris/Kconfig
+++ b/arch/cris/Kconfig
@@ -59,6 +59,7 @@ config CRIS
 	select GENERIC_IOMAP
 	select MODULES_USE_ELF_RELA
 	select CLONE_BACKWARDS2
+	select HAVE_EXIT_THREAD if ETRAX_ARCH_V32
 	select OLD_SIGSUSPEND
 	select OLD_SIGACTION
 	select GPIOLIB
@@ -69,6 +70,7 @@ config CRIS
 	select GENERIC_CLOCKEVENTS if ETRAX_ARCH_V32
 	select GENERIC_SCHED_CLOCK if ETRAX_ARCH_V32
 	select HAVE_DEBUG_BUGVERBOSE if ETRAX_ARCH_V32
+	select HAVE_NMI
 
 config HZ
 	int
diff --git a/arch/cris/arch-v10/kernel/process.c b/arch/cris/arch-v10/kernel/process.c
index 02b783457be0..96e5afef6b47 100644
--- a/arch/cris/arch-v10/kernel/process.c
+++ b/arch/cris/arch-v10/kernel/process.c
@@ -35,15 +35,6 @@ void default_idle(void)
 	local_irq_enable();
 }
 
-/*
- * Free current thread data structures etc..
- */
-
-void exit_thread(void)
-{
-	/* Nothing needs to be done.  */
-}
-
 /* if the watchdog is enabled, we can simply disable interrupts and go
  * into an eternal loop, and the watchdog will reset the CPU after 0.1s
  * if on the other hand the watchdog wasn't enabled, we just enable it and wait
diff --git a/arch/cris/arch-v32/kernel/process.c b/arch/cris/arch-v32/kernel/process.c
index c7ce784a393c..4d1afa9f9fd3 100644
--- a/arch/cris/arch-v32/kernel/process.c
+++ b/arch/cris/arch-v32/kernel/process.c
@@ -33,9 +33,9 @@ void default_idle(void)
  */
 
 extern void deconfigure_bp(long pid);
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	deconfigure_bp(current->pid);
+	deconfigure_bp(tsk->pid);
 }
 
 /*
diff --git a/arch/frv/include/asm/processor.h b/arch/frv/include/asm/processor.h
index ae8d423e79d9..73f0a79ad8e6 100644
--- a/arch/frv/include/asm/processor.h
+++ b/arch/frv/include/asm/processor.h
@@ -97,13 +97,6 @@ extern asmlinkage void *restore_user_regs(const struct user_context *target, ...
 #define forget_segments()		do { } while (0)
 
 /*
- * Free current thread data structures etc..
- */
-static inline void exit_thread(void)
-{
-}
-
-/*
  * Return saved PC of a blocked thread.
  */
 extern unsigned long thread_saved_pc(struct task_struct *tsk);
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 986ea84caaed..aa232de2d4bc 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -20,6 +20,7 @@ config H8300
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZO
 	select HAVE_ARCH_KGDB
+	select CPU_NO_EFFICIENT_FFS
 
 config RWSEM_GENERIC_SPINLOCK
 	def_bool y
diff --git a/arch/h8300/include/asm/processor.h b/arch/h8300/include/asm/processor.h
index 54e3fd83c336..111df7397ac7 100644
--- a/arch/h8300/include/asm/processor.h
+++ b/arch/h8300/include/asm/processor.h
@@ -111,13 +111,6 @@ static inline void release_thread(struct task_struct *dead_task)
 }
 
 /*
- * Free current thread data structures etc..
- */
-static inline void exit_thread(void)
-{
-}
-
-/*
  * Return saved PC of a blocked thread.
  */
 unsigned long thread_saved_pc(struct task_struct *tsk);
diff --git a/arch/hexagon/kernel/process.c b/arch/hexagon/kernel/process.c
index a9ebd471823a..d9edfd3fc52a 100644
--- a/arch/hexagon/kernel/process.c
+++ b/arch/hexagon/kernel/process.c
@@ -137,13 +137,6 @@ void release_thread(struct task_struct *dead_task)
 }
 
 /*
- * Free any architecture-specific thread data structures, etc.
- */
-void exit_thread(void)
-{
-}
-
-/*
  * Some archs flush debug and FPU info here
  */
 void flush_thread(void)
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index b534ebab36ea..f80758cb7157 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -18,6 +18,7 @@ config IA64
 	select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
 	select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
 	select HAVE_UNSTABLE_SCHED_CLOCK
+	select HAVE_EXIT_THREAD
 	select HAVE_IDE
 	select HAVE_OPROFILE
 	select HAVE_KPROBES
diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index 9cd607b06964..2436ad5f92c1 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -4542,8 +4542,8 @@ pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *reg
 
 
 /*
- * called only from exit_thread(): task == current
- * we come here only if current has a context attached (loaded or masked)
+ * called only from exit_thread()
+ * we come here only if the task has a context attached (loaded or masked)
  */
 void
 pfm_exit_thread(struct task_struct *task)
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index b51514957620..aae6c4dc7ae7 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -570,22 +570,22 @@ flush_thread (void)
 }
 
 /*
- * Clean up state associated with current thread.  This is called when
+ * Clean up state associated with a thread.  This is called when
  * the thread calls exit().
  */
 void
-exit_thread (void)
+exit_thread (struct task_struct *tsk)
 {
 
-	ia64_drop_fpu(current);
+	ia64_drop_fpu(tsk);
 #ifdef CONFIG_PERFMON
        /* if needed, stop monitoring and flush state to perfmon context */
-	if (current->thread.pfm_context)
-		pfm_exit_thread(current);
+	if (tsk->thread.pfm_context)
+		pfm_exit_thread(tsk);
 
 	/* free debug register resources */
-	if (current->thread.flags & IA64_THREAD_DBG_VALID)
-		pfm_release_debug_registers(current);
+	if (tsk->thread.flags & IA64_THREAD_DBG_VALID)
+		pfm_release_debug_registers(tsk);
 #endif
 }
 
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index c82b29253991..3cc8498fe0fe 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -17,6 +17,7 @@ config M32R
 	select ARCH_USES_GETTIMEOFFSET
 	select MODULES_USE_ELF_RELA
 	select HAVE_DEBUG_STACKOVERFLOW
+	select CPU_NO_EFFICIENT_FFS
 
 config SBUS
 	bool
diff --git a/arch/m32r/kernel/process.c b/arch/m32r/kernel/process.c
index e69221d581d5..a88b1f01e91f 100644
--- a/arch/m32r/kernel/process.c
+++ b/arch/m32r/kernel/process.c
@@ -101,15 +101,6 @@ void show_regs(struct pt_regs * regs)
 #endif
 }
 
-/*
- * Free current thread data structures etc..
- */
-void exit_thread(void)
-{
-	/* Nothing to do. */
-	DPRINTK("pid = %d\n", current->pid);
-}
-
 void flush_thread(void)
 {
 	DPRINTK("pid = %d\n", current->pid);
diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
index c1beb5ae181f..8ace920ca24a 100644
--- a/arch/m68k/Kconfig.cpu
+++ b/arch/m68k/Kconfig.cpu
@@ -40,6 +40,7 @@ config M68000
 	select CPU_HAS_NO_MULDIV64
 	select CPU_HAS_NO_UNALIGNED
 	select GENERIC_CSUM
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  The Freescale (was Motorola) 68000 CPU is the first generation of
 	  the well known M68K family of processors. The CPU core as well as
@@ -51,6 +52,7 @@ config MCPU32
 	bool
 	select CPU_HAS_NO_BITFIELDS
 	select CPU_HAS_NO_UNALIGNED
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  The Freescale (was then Motorola) CPU32 is a CPU core that is
 	  based on the 68020 processor. For the most part it is used in
@@ -130,6 +132,7 @@ config M5206
 	depends on !MMU
 	select COLDFIRE_SW_A7
 	select HAVE_MBAR
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  Motorola ColdFire 5206 processor support.
 
@@ -138,6 +141,7 @@ config M5206e
 	depends on !MMU
 	select COLDFIRE_SW_A7
 	select HAVE_MBAR
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  Motorola ColdFire 5206e processor support.
 
@@ -163,6 +167,7 @@ config M5249
 	depends on !MMU
 	select COLDFIRE_SW_A7
 	select HAVE_MBAR
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  Motorola ColdFire 5249 processor support.
 
@@ -171,6 +176,7 @@ config M525x
 	depends on !MMU
 	select COLDFIRE_SW_A7
 	select HAVE_MBAR
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  Freescale (Motorola) Coldfire 5251/5253 processor support.
 
@@ -189,6 +195,7 @@ config M5272
 	depends on !MMU
 	select COLDFIRE_SW_A7
 	select HAVE_MBAR
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  Motorola ColdFire 5272 processor support.
 
@@ -217,6 +224,7 @@ config M5307
 	select COLDFIRE_SW_A7
 	select HAVE_CACHE_CB
 	select HAVE_MBAR
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  Motorola ColdFire 5307 processor support.
 
@@ -242,6 +250,7 @@ config M5407
 	select COLDFIRE_SW_A7
 	select HAVE_CACHE_CB
 	select HAVE_MBAR
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  Motorola ColdFire 5407 processor support.
 
@@ -251,6 +260,7 @@ config M547x
 	select MMU_COLDFIRE if MMU
 	select HAVE_CACHE_CB
 	select HAVE_MBAR
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  Freescale ColdFire 5470/5471/5472/5473/5474/5475 processor support.
 
@@ -260,6 +270,7 @@ config M548x
 	select M54xx
 	select HAVE_CACHE_CB
 	select HAVE_MBAR
+	select CPU_NO_EFFICIENT_FFS
 	help
 	  Freescale ColdFire 5480/5481/5482/5483/5484/5485 processor support.
 
diff --git a/arch/m68k/include/asm/processor.h b/arch/m68k/include/asm/processor.h
index 20dda1d4b860..a6ce2ec8d693 100644
--- a/arch/m68k/include/asm/processor.h
+++ b/arch/m68k/include/asm/processor.h
@@ -153,13 +153,6 @@ static inline void release_thread(struct task_struct *dead_task)
 {
 }
 
-/*
- * Free current thread data structures etc..
- */
-static inline void exit_thread(void)
-{
-}
-
 extern unsigned long thread_saved_pc(struct task_struct *tsk);
 
 unsigned long get_wchan(struct task_struct *p);
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index a0fa88da3e31..5b7a45d99cfb 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -11,6 +11,7 @@ config METAG
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DEBUG_STACKOVERFLOW
 	select HAVE_DYNAMIC_FTRACE
+	select HAVE_EXIT_THREAD
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_TRACER
 	select HAVE_KERNEL_BZIP2
@@ -29,6 +30,7 @@ config METAG
 	select OF
 	select OF_EARLY_FLATTREE
 	select SPARSE_IRQ
+	select CPU_NO_EFFICIENT_FFS
 
 config STACKTRACE_SUPPORT
 	def_bool y
diff --git a/arch/metag/include/asm/processor.h b/arch/metag/include/asm/processor.h
index 0838ca699764..a0333ebcac35 100644
--- a/arch/metag/include/asm/processor.h
+++ b/arch/metag/include/asm/processor.h
@@ -134,8 +134,6 @@ static inline void release_thread(struct task_struct *dead_task)
 #define copy_segments(tsk, mm)		do { } while (0)
 #define release_segments(mm)		do { } while (0)
 
-extern void exit_thread(void);
-
 /*
  * Return saved PC of a blocked thread.
  */
diff --git a/arch/metag/kernel/process.c b/arch/metag/kernel/process.c
index 7f546183a0f0..35062796edf2 100644
--- a/arch/metag/kernel/process.c
+++ b/arch/metag/kernel/process.c
@@ -345,10 +345,10 @@ void flush_thread(void)
 /*
  * Free current thread data structures etc.
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	clear_fpu(&current->thread);
-	clear_dsp(&current->thread);
+	clear_fpu(&tsk->thread);
+	clear_dsp(&tsk->thread);
 }
 
 /* TODO: figure out how to unwind the kernel stack here to figure out
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 3d793b55f60c..f17c3a4fb697 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -32,6 +32,7 @@ config MICROBLAZE
 	select OF_EARLY_FLATTREE
 	select TRACING_SUPPORT
 	select VIRT_TO_BUS
+	select CPU_NO_EFFICIENT_FFS
 
 config SWAP
 	def_bool n
diff --git a/arch/microblaze/include/asm/processor.h b/arch/microblaze/include/asm/processor.h
index 497a988d79c2..c38d0dd91134 100644
--- a/arch/microblaze/include/asm/processor.h
+++ b/arch/microblaze/include/asm/processor.h
@@ -70,11 +70,6 @@ static inline void release_thread(struct task_struct *dead_task)
 {
 }
 
-/* Free all resources held by a thread. */
-static inline void exit_thread(void)
-{
-}
-
 extern unsigned long thread_saved_pc(struct task_struct *t);
 
 extern unsigned long get_wchan(struct task_struct *p);
@@ -127,11 +122,6 @@ static inline void release_thread(struct task_struct *dead_task)
 {
 }
 
-/* Free current thread data structures etc.  */
-static inline void exit_thread(void)
-{
-}
-
 /* Return saved (kernel) PC of a blocked thread.  */
 #  define thread_saved_pc(tsk)	\
 	((tsk)->thread.regs ? (tsk)->thread.regs->r15 : 0)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 5663f411c225..8040fb1845b4 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -48,6 +48,7 @@ config MIPS
 	select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
 	select GENERIC_CMOS_UPDATE
 	select HAVE_MOD_ARCH_SPECIFIC
+	select HAVE_NMI
 	select VIRT_TO_BUS
 	select MODULES_USE_ELF_REL if MODULES
 	select MODULES_USE_ELF_RELA if MODULES && 64BIT
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index e6f19fc61bf2..e961c8a7ea66 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -204,6 +204,16 @@
 #endif
 #endif
 
+/* __builtin_constant_p(cpu_has_mips_r) && cpu_has_mips_r */
+#if !((defined(cpu_has_mips32r1) && cpu_has_mips32r1) || \
+	  (defined(cpu_has_mips32r2) && cpu_has_mips32r2) || \
+	  (defined(cpu_has_mips32r6) && cpu_has_mips32r6) || \
+	  (defined(cpu_has_mips64r1) && cpu_has_mips64r1) || \
+	  (defined(cpu_has_mips64r2) && cpu_has_mips64r2) || \
+	  (defined(cpu_has_mips64r6) && cpu_has_mips64r6))
+#define CPU_NO_EFFICIENT_FFS 1
+#endif
+
 #ifndef cpu_has_mips_1
 # define cpu_has_mips_1		(!cpu_has_mips_r6)
 #endif
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index a6b3dc54260a..411c971e3417 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -73,10 +73,6 @@ void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
 	regs->regs[29] = sp;
 }
 
-void exit_thread(void)
-{
-}
-
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {
 	/*
diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index 06ddb5501ab1..9627e81a6cbb 100644
--- a/arch/mn10300/Kconfig
+++ b/arch/mn10300/Kconfig
@@ -1,5 +1,6 @@
 config MN10300
 	def_bool y
+	select HAVE_EXIT_THREAD
 	select HAVE_OPROFILE
 	select HAVE_UID16
 	select GENERIC_IRQ_SHOW
diff --git a/arch/mn10300/include/asm/fpu.h b/arch/mn10300/include/asm/fpu.h
index 738ff72659d5..a47e995d45f3 100644
--- a/arch/mn10300/include/asm/fpu.h
+++ b/arch/mn10300/include/asm/fpu.h
@@ -76,11 +76,9 @@ static inline void unlazy_fpu(struct task_struct *tsk)
 	preempt_enable();
 }
 
-static inline void exit_fpu(void)
+static inline void exit_fpu(struct task_struct *tsk)
 {
 #ifdef CONFIG_LAZY_SAVE_FPU
-	struct task_struct *tsk = current;
-
 	preempt_disable();
 	if (fpu_state_owner == tsk)
 		fpu_state_owner = NULL;
@@ -123,7 +121,7 @@ static inline void fpu_init_state(void) {}
 static inline void fpu_save(struct fpu_state_struct *s) {}
 static inline void fpu_kill_state(struct task_struct *tsk) {}
 static inline void unlazy_fpu(struct task_struct *tsk) {}
-static inline void exit_fpu(void) {}
+static inline void exit_fpu(struct task_struct *tsk) {}
 static inline void flush_fpu(void) {}
 static inline int fpu_setup_sigcontext(struct fpucontext *buf) { return 0; }
 static inline int fpu_restore_sigcontext(struct fpucontext *buf) { return 0; }
diff --git a/arch/mn10300/kernel/process.c b/arch/mn10300/kernel/process.c
index 3707da583d05..cbede4e88dee 100644
--- a/arch/mn10300/kernel/process.c
+++ b/arch/mn10300/kernel/process.c
@@ -103,9 +103,9 @@ void show_regs(struct pt_regs *regs)
 /*
  * free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	exit_fpu();
+	exit_fpu(tsk);
 }
 
 void flush_thread(void)
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index 87ca653eb5f3..51a56c8b04b4 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -15,6 +15,7 @@ config NIOS2
 	select SOC_BUS
 	select SPARSE_IRQ
 	select USB_ARCH_HAS_HCD if USB_SUPPORT
+	select CPU_NO_EFFICIENT_FFS
 
 config GENERIC_CSUM
 	def_bool y
diff --git a/arch/nios2/include/asm/processor.h b/arch/nios2/include/asm/processor.h
index c2ba45c159c7..1c953f0cadbf 100644
--- a/arch/nios2/include/asm/processor.h
+++ b/arch/nios2/include/asm/processor.h
@@ -75,11 +75,6 @@ static inline void release_thread(struct task_struct *dead_task)
 {
 }
 
-/* Free current thread data structures etc.. */
-static inline void exit_thread(void)
-{
-}
-
 /* Return saved PC of a blocked thread. */
 #define thread_saved_pc(tsk)	((tsk)->thread.kregs->ea)
 
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index e118c02cc79a..142cb057c41b 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -25,6 +25,7 @@ config OPENRISC
 	select MODULES_USE_ELF_RELA
 	select HAVE_DEBUG_STACKOVERFLOW
 	select OR1K_PIC
+	select CPU_NO_EFFICIENT_FFS if !OPENRISC_HAVE_INST_FF1
 
 config MMU
 	def_bool y
diff --git a/arch/openrisc/include/asm/processor.h b/arch/openrisc/include/asm/processor.h
index 4d235e3d2534..70334c9f7d24 100644
--- a/arch/openrisc/include/asm/processor.h
+++ b/arch/openrisc/include/asm/processor.h
@@ -85,15 +85,6 @@ void release_thread(struct task_struct *);
 unsigned long get_wchan(struct task_struct *p);
 
 /*
- * Free current thread data structures etc..
- */
-
-extern inline void exit_thread(void)
-{
-	/* Nothing needs to be done.  */
-}
-
-/*
  * Return saved PC of a blocked thread. For now, this is the "user" PC
  */
 extern unsigned long thread_saved_pc(struct task_struct *t);
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 88cfaa8af78e..3d498a676551 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -32,6 +32,7 @@ config PARISC
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_SECCOMP_FILTER
 	select ARCH_NO_COHERENT_DMA_MMAP
+	select CPU_NO_EFFICIENT_FFS
 
 	help
 	  The PA-RISC microprocessor is designed by Hewlett-Packard and used
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index 809905a811ed..40639439d8b3 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -144,13 +144,6 @@ void machine_power_off(void)
 void (*pm_power_off)(void) = machine_power_off;
 EXPORT_SYMBOL(pm_power_off);
 
-/*
- * Free current thread data structures etc..
- */
-void exit_thread(void)
-{
-}
-
 void flush_thread(void)
 {
 	/* Only needs to handle fpu stuff or perf monitors.
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index f0403b58ae8b..01f7464d9fea 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -155,6 +155,7 @@ config PPC
 	select NO_BOOTMEM
 	select HAVE_GENERIC_RCU_GUP
 	select HAVE_PERF_EVENTS_NMI if PPC64
+	select HAVE_NMI if PERF_EVENTS
 	select EDAC_SUPPORT
 	select EDAC_ATOMIC_SCRUB
 	select ARCH_HAS_DMA_SET_COHERENT_MASK
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ea8a28fd6f31..e2f12cbcade9 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1329,10 +1329,6 @@ void show_regs(struct pt_regs * regs)
 		show_instructions(regs);
 }
 
-void exit_thread(void)
-{
-}
-
 void flush_thread(void)
 {
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index de0fcc08dff5..a8c259059adf 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -123,6 +123,7 @@ config S390
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_EARLY_PFN_TO_NID
 	select HAVE_ARCH_JUMP_LABEL
+	select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
 	select HAVE_ARCH_SECCOMP_FILTER
 	select HAVE_ARCH_SOFT_DIRTY
 	select HAVE_ARCH_TRACEHOOK
@@ -134,6 +135,7 @@ config S390
 	select HAVE_DMA_API_DEBUG
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS
+	select HAVE_EXIT_THREAD
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
@@ -165,6 +167,7 @@ config S390
 	select TTY
 	select VIRT_CPU_ACCOUNTING
 	select VIRT_TO_BUS
+	select HAVE_NMI
 
 
 config SCHED_OMIT_FRAME_POINTER
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 481d7a83efc6..bba4fa74b321 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -68,9 +68,10 @@ extern void kernel_thread_starter(void);
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	exit_thread_runtime_instr();
+	if (tsk == current)
+		exit_thread_runtime_instr();
 }
 
 void flush_thread(void)
diff --git a/arch/score/Kconfig b/arch/score/Kconfig
index 366e1b599a7b..507d63181389 100644
--- a/arch/score/Kconfig
+++ b/arch/score/Kconfig
@@ -14,6 +14,7 @@ config SCORE
 	select VIRT_TO_BUS
 	select MODULES_USE_ELF_REL
 	select CLONE_BACKWARDS
+	select CPU_NO_EFFICIENT_FFS
 
 choice
 	prompt "System type"
diff --git a/arch/score/kernel/process.c b/arch/score/kernel/process.c
index a1519ad3d49d..aae9480706c2 100644
--- a/arch/score/kernel/process.c
+++ b/arch/score/kernel/process.c
@@ -56,8 +56,6 @@ void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
 	regs->regs[0] = sp;
 }
 
-void exit_thread(void) {}
-
 /*
  * When a process does an "exec", machine state like FPU and debug
  * registers need to be reset.  This is a hook function for that.
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 7ed20fc3fc81..e803a836cb7c 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -20,6 +20,7 @@ config SUPERH
 	select PERF_USE_VMALLOC
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_KERNEL_GZIP
+	select CPU_NO_EFFICIENT_FFS
 	select HAVE_KERNEL_BZIP2
 	select HAVE_KERNEL_LZMA
 	select HAVE_KERNEL_XZ
@@ -44,6 +45,7 @@ config SUPERH
 	select OLD_SIGSUSPEND
 	select OLD_SIGACTION
 	select HAVE_ARCH_AUDITSYSCALL
+	select HAVE_NMI
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast
@@ -71,6 +73,7 @@ config SUPERH32
 
 config SUPERH64
 	def_bool ARCH = "sh64"
+	select HAVE_EXIT_THREAD
 	select KALLSYMS
 
 config ARCH_DEFCONFIG
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 2885fc9d9dcd..ee12e9451874 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -76,13 +76,6 @@ void start_thread(struct pt_regs *regs, unsigned long new_pc,
 }
 EXPORT_SYMBOL(start_thread);
 
-/*
- * Free current thread data structures etc..
- */
-void exit_thread(void)
-{
-}
-
 void flush_thread(void)
 {
 	struct task_struct *tsk = current;
diff --git a/arch/sh/kernel/process_64.c b/arch/sh/kernel/process_64.c
index e2062e643341..9d3e9916555d 100644
--- a/arch/sh/kernel/process_64.c
+++ b/arch/sh/kernel/process_64.c
@@ -288,7 +288,7 @@ void show_regs(struct pt_regs *regs)
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
 	/*
 	 * See arch/sparc/kernel/process.c for the precedent for doing
@@ -307,9 +307,8 @@ void exit_thread(void)
 	 * which it would get safely nulled.
 	 */
 #ifdef CONFIG_SH_FPU
-	if (last_task_used_math == current) {
+	if (last_task_used_math == tsk)
 		last_task_used_math = NULL;
-	}
 #endif
 }
 
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index db0a26cffa97..546293d9e6c5 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -20,6 +20,7 @@ config SPARC
 	select HAVE_OPROFILE
 	select HAVE_ARCH_KGDB if !SMP || SPARC64
 	select HAVE_ARCH_TRACEHOOK
+	select HAVE_EXIT_THREAD
 	select SYSCTL_EXCEPTION_TRACE
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select RTC_CLASS
@@ -41,6 +42,7 @@ config SPARC
 	select ODD_RT_SIGACTION
 	select OLD_SIGSUSPEND
 	select ARCH_HAS_SG_CHAIN
+	select CPU_NO_EFFICIENT_FFS
 
 config SPARC32
 	def_bool !64BIT
@@ -78,6 +80,7 @@ config SPARC64
 	select NO_BOOTMEM
 	select HAVE_ARCH_AUDITSYSCALL
 	select ARCH_SUPPORTS_ATOMIC_RMW
+	select HAVE_NMI
 
 config ARCH_DEFCONFIG
 	string
diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index c5113c7ce2fd..b7780a5bef11 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -184,21 +184,21 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
 #ifndef CONFIG_SMP
-	if(last_task_used_math == current) {
+	if (last_task_used_math == tsk) {
 #else
-	if (test_thread_flag(TIF_USEDFPU)) {
+	if (test_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU)) {
 #endif
 		/* Keep process from leaving FPU in a bogon state. */
 		put_psr(get_psr() | PSR_EF);
-		fpsave(&current->thread.float_regs[0], &current->thread.fsr,
-		       &current->thread.fpqueue[0], &current->thread.fpqdepth);
+		fpsave(&tsk->thread.float_regs[0], &tsk->thread.fsr,
+		       &tsk->thread.fpqueue[0], &tsk->thread.fpqdepth);
 #ifndef CONFIG_SMP
 		last_task_used_math = NULL;
 #else
-		clear_thread_flag(TIF_USEDFPU);
+		clear_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU);
 #endif
 	}
 }
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index c16ef1af1843..fa14402b33f9 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -417,9 +417,9 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 }
 
 /* Free current thread data structures etc.. */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	struct thread_info *t = current_thread_info();
+	struct thread_info *t = task_thread_info(tsk);
 
 	if (t->utraps) {
 		if (t->utraps[0] < 2)
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 81719302b056..76989b878f3c 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -3,6 +3,7 @@
 
 config TILE
 	def_bool y
+	select HAVE_EXIT_THREAD
 	select HAVE_PERF_EVENTS
 	select USE_PMC if PERF_EVENTS
 	select HAVE_DMA_API_DEBUG
@@ -29,6 +30,7 @@ config TILE
 	select HAVE_DEBUG_STACKOVERFLOW
 	select ARCH_WANT_FRAME_POINTERS
 	select HAVE_CONTEXT_TRACKING
+	select HAVE_NMI if USE_PMC
 	select EDAC_SUPPORT
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index b5f30d376ce1..6b705ccc9cc1 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -541,7 +541,7 @@ void flush_thread(void)
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
 #ifdef CONFIG_HARDWALL
 	/*
@@ -550,7 +550,7 @@ void exit_thread(void)
 	 * the last reference to a hardwall fd, it would already have
 	 * been released and deactivated at this point.)
 	 */
-	hardwall_deactivate_all(current);
+	hardwall_deactivate_all(tsk);
 #endif
 }
 
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 48af59aae129..0b04711f1f18 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -103,10 +103,6 @@ void interrupt_end(void)
 		tracehook_notify_resume(regs);
 }
 
-void exit_thread(void)
-{
-}
-
 int get_current_pid(void)
 {
 	return task_pid_nr(current);
diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c
index b008e9961465..00299c927852 100644
--- a/arch/unicore32/kernel/process.c
+++ b/arch/unicore32/kernel/process.c
@@ -201,13 +201,6 @@ void show_regs(struct pt_regs *regs)
 	__backtrace();
 }
 
-/*
- * Free current thread data structures etc..
- */
-void exit_thread(void)
-{
-}
-
 void flush_thread(void)
 {
 	struct thread_info *thread = current_thread_info();
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 15f827678843..48ac29034e1e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -105,6 +105,7 @@ config X86
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
+	select HAVE_EXIT_THREAD
 	select HAVE_FENTRY			if X86_64
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_FP_TEST
@@ -130,6 +131,7 @@ config X86
 	select HAVE_MEMBLOCK
 	select HAVE_MEMBLOCK_NODE_MAP
 	select HAVE_MIXED_BREAKPOINTS_REGS
+	select HAVE_NMI
 	select HAVE_OPROFILE
 	select HAVE_OPTPROBES
 	select HAVE_PCSPKR_PLATFORM
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 12f9653bde8d..2982387ba817 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -5,6 +5,7 @@
  */
 #include <linux/errno.h>
 #include <linux/compiler.h>
+#include <linux/kasan-checks.h>
 #include <linux/thread_info.h>
 #include <linux/string.h>
 #include <asm/asm.h>
@@ -721,6 +722,8 @@ copy_from_user(void *to, const void __user *from, unsigned long n)
 
 	might_fault();
 
+	kasan_check_write(to, n);
+
 	/*
 	 * While we would like to have the compiler do the checking for us
 	 * even in the non-constant size case, any false positives there are
@@ -754,6 +757,8 @@ copy_to_user(void __user *to, const void *from, unsigned long n)
 {
 	int sz = __compiletime_object_size(from);
 
+	kasan_check_read(from, n);
+
 	might_fault();
 
 	/* See the comment in copy_from_user() above. */
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index 307698688fa1..2eac2aa3e37f 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -7,6 +7,7 @@
 #include <linux/compiler.h>
 #include <linux/errno.h>
 #include <linux/lockdep.h>
+#include <linux/kasan-checks.h>
 #include <asm/alternative.h>
 #include <asm/cpufeatures.h>
 #include <asm/page.h>
@@ -109,6 +110,7 @@ static __always_inline __must_check
 int __copy_from_user(void *dst, const void __user *src, unsigned size)
 {
 	might_fault();
+	kasan_check_write(dst, size);
 	return __copy_from_user_nocheck(dst, src, size);
 }
 
@@ -175,6 +177,7 @@ static __always_inline __must_check
 int __copy_to_user(void __user *dst, const void *src, unsigned size)
 {
 	might_fault();
+	kasan_check_read(src, size);
 	return __copy_to_user_nocheck(dst, src, size);
 }
 
@@ -242,12 +245,14 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
 static __must_check __always_inline int
 __copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
 {
+	kasan_check_write(dst, size);
 	return __copy_from_user_nocheck(dst, src, size);
 }
 
 static __must_check __always_inline int
 __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
 {
+	kasan_check_read(src, size);
 	return __copy_to_user_nocheck(dst, src, size);
 }
 
@@ -258,6 +263,7 @@ static inline int
 __copy_from_user_nocache(void *dst, const void __user *src, unsigned size)
 {
 	might_fault();
+	kasan_check_write(dst, size);
 	return __copy_user_nocache(dst, src, size, 1);
 }
 
@@ -265,6 +271,7 @@ static inline int
 __copy_from_user_inatomic_nocache(void *dst, const void __user *src,
 				  unsigned size)
 {
+	kasan_check_write(dst, size);
 	return __copy_user_nocache(dst, src, size, 0);
 }
 
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
index 045e424fb368..7788ce643bf4 100644
--- a/arch/x86/kernel/apic/hw_nmi.c
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -18,7 +18,6 @@
 #include <linux/nmi.h>
 #include <linux/module.h>
 #include <linux/delay.h>
-#include <linux/seq_buf.h>
 
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 u64 hw_nmi_get_sample_period(int watchdog_thresh)
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 2915d54e9dd5..96becbbb52e0 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -97,10 +97,9 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	struct task_struct *me = current;
-	struct thread_struct *t = &me->thread;
+	struct thread_struct *t = &tsk->thread;
 	unsigned long *bp = t->io_bitmap_ptr;
 	struct fpu *fpu = &t->fpu;
 
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 85257afe71c3..64336f666fb6 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -14,6 +14,7 @@ config XTENSA
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK
 	select HAVE_DMA_API_DEBUG
+	select HAVE_EXIT_THREAD
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUTEX_CMPXCHG if !MMU
 	select HAVE_HW_BREAKPOINT if PERF_EVENTS
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 5bbfed81c97b..e0ded48561db 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -115,10 +115,10 @@ void arch_cpu_idle(void)
 /*
  * This is called when the thread calls exit().
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
 #if XTENSA_HAVE_COPROCESSORS
-	coprocessor_release_all(current_thread_info());
+	coprocessor_release_all(task_thread_info(tsk));
 #endif
 }