Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits)
  sched, trace: update trace_sched_wakeup()
  tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3
  Revert "x86: disable X86_PTRACE_BTS"
  ring-buffer: prevent false positive warning
  ring-buffer: fix dangling commit race
  ftrace: enable format arguments checking
  x86, bts: memory accounting
  x86, bts: add fork and exit handling
  ftrace: introduce tracing_reset_online_cpus() helper
  tracing: fix warnings in kernel/trace/trace_sched_switch.c
  tracing: fix warning in kernel/trace/trace.c
  tracing/ring-buffer: remove unused ring_buffer size
  trace: fix task state printout
  ftrace: add not to regex on filtering functions
  trace: better use of stack_trace_enabled for boot up code
  trace: add a way to enable or disable the stack tracer
  x86: entry_64 - introduce FTRACE_ frame macro v2
  tracing/ftrace: add the printk-msg-only option
  tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()
  x86, bts: correctly report invalid bts records
  ...

Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits
being already partly merged by the SH merge.

23 files changed, 1465 insertions, 923 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 1f208aaee78..88dd768eab6 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -66,6 +66,7 @@ obj-$(CONFIG_X86_LOCAL_APIC)	+= apic.o nmi.o
 obj-$(CONFIG_X86_IO_APIC)	+= io_apic.o
 obj-$(CONFIG_X86_REBOOTFIXUPS)	+= reboot_fixups_32.o
 obj-$(CONFIG_DYNAMIC_FTRACE)	+= ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
 obj-$(CONFIG_KEXEC)		+= machine_kexec_$(BITS).o
 obj-$(CONFIG_KEXEC)		+= relocate_kernel_$(BITS).o crash.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump_$(BITS).o
diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index 7397911f847..b5229affb95 100644
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -30,6 +30,7 @@
 #include <linux/module.h>
 #include <linux/dmi.h>
 #include <linux/dmar.h>
+#include <linux/ftrace.h>
 
 #include <asm/atomic.h>
 #include <asm/smp.h>
@@ -790,7 +791,7 @@ static void local_apic_timer_interrupt(void)
  * [ if a single-CPU system runs an SMP kernel then we call the local
  *   interrupt as well. Thus we cannot inline the local irq ... ]
  */
-void smp_apic_timer_interrupt(struct pt_regs *regs)
+void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index a5c04e88777..82db7f45e2d 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -2,6 +2,11 @@
 # Makefile for x86-compatible CPU details and quirks
 #
 
+# Don't trace early stages of a secondary CPU boot
+ifdef CONFIG_FUNCTION_TRACER
+CFLAGS_REMOVE_common.o = -pg
+endif
+
 obj-y			:= intel_cacheinfo.o addon_cpuid_features.o
 obj-y			+= proc.o capflags.o powerflags.o common.o
 obj-y			+= vmware.o hypervisor.o
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index 8e48c5d4467..88ea02dcb62 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -33,6 +33,7 @@
 #include <linux/cpufreq.h>
 #include <linux/compiler.h>
 #include <linux/dmi.h>
+#include <linux/ftrace.h>
 
 #include <linux/acpi.h>
 #include <acpi/processor.h>
@@ -391,6 +392,7 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 	unsigned int next_perf_state = 0; /* Index into perf table */
 	unsigned int i;
 	int result = 0;
+	struct power_trace it;
 
 	dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
 
@@ -427,6 +429,8 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 		}
 	}
 
+	trace_power_mark(&it, POWER_PSTATE, next_perf_state);
+
 	switch (data->cpu_feature) {
 	case SYSTEM_INTEL_MSR_CAPABLE:
 		cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index ccfd2047630..8ea6929e974 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -11,7 +11,6 @@
 #include <asm/pgtable.h>
 #include <asm/msr.h>
 #include <asm/uaccess.h>
-#include <asm/ptrace.h>
 #include <asm/ds.h>
 #include <asm/bugs.h>
 
@@ -326,9 +325,6 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
 		set_cpu_cap(c, X86_FEATURE_P3);
 #endif
 
-	if (cpu_has_bts)
-		ptrace_bts_init_intel(c);
-
 	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
 		/*
 		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index d6938d9351c..da91701a234 100644
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@ -6,14 +6,13 @@
  * precise-event based sampling (PEBS).
  *
  * It manages:
- * - per-thread and per-cpu allocation of BTS and PEBS
- * - buffer memory allocation (optional)
- * - buffer overflow handling
+ * - DS and BTS hardware configuration
+ * - buffer overflow handling (to be done)
  * - buffer access
  *
- * It assumes:
- * - get_task_struct on all parameter tasks
- * - current is allowed to trace parameter tasks
+ * It does not do:
+ * - security checking (is the caller allowed to trace the task)
+ * - buffer allocation (memory accounting)
  *
  *
  * Copyright (C) 2007-2008 Intel Corporation.
@@ -28,22 +27,69 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
+#include <linux/kernel.h>
 
 
 /*
  * The configuration for a particular DS hardware implementation.
  */
 struct ds_configuration {
-	/* the size of the DS structure in bytes */
-	unsigned char  sizeof_ds;
-	/* the size of one pointer-typed field in the DS structure in bytes;
-	   this covers the first 8 fields related to buffer management. */
+	/* the name of the configuration */
+	const char *name;
+	/* the size of one pointer-typed field in the DS structure and
+	   in the BTS and PEBS buffers in bytes;
+	   this covers the first 8 DS fields related to buffer management. */
 	unsigned char  sizeof_field;
 	/* the size of a BTS/PEBS record in bytes */
 	unsigned char  sizeof_rec[2];
+	/* a series of bit-masks to control various features indexed
+	 * by enum ds_feature */
+	unsigned long ctl[dsf_ctl_max];
 };
-static struct ds_configuration ds_cfg;
+static DEFINE_PER_CPU(struct ds_configuration, ds_cfg_array);
 
+#define ds_cfg per_cpu(ds_cfg_array, smp_processor_id())
+
+#define MAX_SIZEOF_DS (12 * 8)	/* maximal size of a DS configuration */
+#define MAX_SIZEOF_BTS (3 * 8)	/* maximal size of a BTS record */
+#define DS_ALIGNMENT (1 << 3)	/* BTS and PEBS buffer alignment */
+
+#define BTS_CONTROL \
+ (ds_cfg.ctl[dsf_bts] | ds_cfg.ctl[dsf_bts_kernel] | ds_cfg.ctl[dsf_bts_user] |\
+  ds_cfg.ctl[dsf_bts_overflow])
+
+
+/*
+ * A BTS or PEBS tracer.
+ *
+ * This holds the configuration of the tracer and serves as a handle
+ * to identify tracers.
+ */
+struct ds_tracer {
+	/* the DS context (partially) owned by this tracer */
+	struct ds_context *context;
+	/* the buffer provided on ds_request() and its size in bytes */
+	void *buffer;
+	size_t size;
+};
+
+struct bts_tracer {
+	/* the common DS part */
+	struct ds_tracer ds;
+	/* the trace including the DS configuration */
+	struct bts_trace trace;
+	/* buffer overflow notification function */
+	bts_ovfl_callback_t ovfl;
+};
+
+struct pebs_tracer {
+	/* the common DS part */
+	struct ds_tracer ds;
+	/* the trace including the DS configuration */
+	struct pebs_trace trace;
+	/* buffer overflow notification function */
+	pebs_ovfl_callback_t ovfl;
+};
 
 /*
  * Debug Store (DS) save area configuration (see Intel64 and IA32
@@ -109,32 +155,9 @@ static inline void ds_set(unsigned char *base, enum ds_qualifier qual,
 
 
 /*
- * Locking is done only for allocating BTS or PEBS resources and for
- * guarding context and buffer memory allocation.
- *
- * Most functions require the current task to own the ds context part
- * they are going to access. All the locking is done when validating
- * access to the context.
+ * Locking is done only for allocating BTS or PEBS resources.
  */
-static spinlock_t ds_lock = __SPIN_LOCK_UNLOCKED(ds_lock);
-
-/*
- * Validate that the current task is allowed to access the BTS/PEBS
- * buffer of the parameter task.
- *
- * Returns 0, if access is granted; -Eerrno, otherwise.
- */
-static inline int ds_validate_access(struct ds_context *context,
-				     enum ds_qualifier qual)
-{
-	if (!context)
-		return -EPERM;
-
-	if (context->owner[qual] == current)
-		return 0;
-
-	return -EPERM;
-}
+static DEFINE_SPINLOCK(ds_lock);
 
 
 /*
@@ -150,27 +173,32 @@ static inline int ds_validate_access(struct ds_context *context,
  *   >0  number of per-thread tracers
  *   <0  number of per-cpu tracers
  *
- * The below functions to get and put tracers and to check the
- * allocation type require the ds_lock to be held by the caller.
- *
  * Tracers essentially gives the number of ds contexts for a certain
  * type of allocation.
  */
-static long tracers;
+static atomic_t tracers = ATOMIC_INIT(0);
 
 static inline void get_tracer(struct task_struct *task)
 {
-	tracers += (task ? 1 : -1);
+	if (task)
+		atomic_inc(&tracers);
+	else
+		atomic_dec(&tracers);
 }
 
 static inline void put_tracer(struct task_struct *task)
 {
-	tracers -= (task ? 1 : -1);
+	if (task)
+		atomic_dec(&tracers);
+	else
+		atomic_inc(&tracers);
 }
 
 static inline int check_tracer(struct task_struct *task)
 {
-	return (task ? (tracers >= 0) : (tracers <= 0));
+	return task ?
+		(atomic_read(&tracers) >= 0) :
+		(atomic_read(&tracers) <= 0);
 }
 
 
@@ -183,99 +211,70 @@ static inline int check_tracer(struct task_struct *task)
  *
  * Contexts are use-counted. They are allocated on first access and
  * deallocated when the last user puts the context.
- *
- * We distinguish between an allocating and a non-allocating get of a
- * context:
- * - the allocating get is used for requesting BTS/PEBS resources. It
- *   requires the caller to hold the global ds_lock.
- * - the non-allocating get is used for all other cases. A
- *   non-existing context indicates an error. It acquires and releases
- *   the ds_lock itself for obtaining the context.
- *
- * A context and its DS configuration are allocated and deallocated
- * together. A context always has a DS configuration of the
- * appropriate size.
  */
-static DEFINE_PER_CPU(struct ds_context *, system_context);
-
-#define this_system_context per_cpu(system_context, smp_processor_id())
-
-/*
- * Returns the pointer to the parameter task's context or to the
- * system-wide context, if task is NULL.
- *
- * Increases the use count of the returned context, if not NULL.
- */
-static inline struct ds_context *ds_get_context(struct task_struct *task)
-{
-	struct ds_context *context;
-	unsigned long irq;
+struct ds_context {
+	/* pointer to the DS configuration; goes into MSR_IA32_DS_AREA */
+	unsigned char ds[MAX_SIZEOF_DS];
+	/* the owner of the BTS and PEBS configuration, respectively */
+	struct bts_tracer *bts_master;
+	struct pebs_tracer *pebs_master;
+	/* use count */
+	unsigned long count;
+	/* a pointer to the context location inside the thread_struct
+	 * or the per_cpu context array */
+	struct ds_context **this;
+	/* a pointer to the task owning this context, or NULL, if the
+	 * context is owned by a cpu */
+	struct task_struct *task;
+};
 
-	spin_lock_irqsave(&ds_lock, irq);
+static DEFINE_PER_CPU(struct ds_context *, system_context_array);
 
-	context = (task ? task->thread.ds_ctx : this_system_context);
-	if (context)
-		context->count++;
+#define system_context per_cpu(system_context_array, smp_processor_id())
 
-	spin_unlock_irqrestore(&ds_lock, irq);
-
-	return context;
-}
 
-/*
- * Same as ds_get_context, but allocates the context and it's DS
- * structure, if necessary; returns NULL; if out of memory.
- */
-static inline struct ds_context *ds_alloc_context(struct task_struct *task)
+static inline struct ds_context *ds_get_context(struct task_struct *task)
 {
 	struct ds_context **p_context =
-		(task ? &task->thread.ds_ctx : &this_system_context);
-	struct ds_context *context = *p_context;
+		(task ? &task->thread.ds_ctx : &system_context);
+	struct ds_context *context = NULL;
+	struct ds_context *new_context = NULL;
 	unsigned long irq;
 
-	if (!context) {
-		context = kzalloc(sizeof(*context), GFP_KERNEL);
-		if (!context)
-			return NULL;
-
-		context->ds = kzalloc(ds_cfg.sizeof_ds, GFP_KERNEL);
-		if (!context->ds) {
-			kfree(context);
-			return NULL;
-		}
+	/* Chances are small that we already have a context. */
+	new_context = kzalloc(sizeof(*new_context), GFP_KERNEL);
+	if (!new_context)
+		return NULL;
 
-		spin_lock_irqsave(&ds_lock, irq);
+	spin_lock_irqsave(&ds_lock, irq);
 
-		if (*p_context) {
-			kfree(context->ds);
-			kfree(context);
+	context = *p_context;
+	if (!context) {
+		context = new_context;
 
-			context = *p_context;
-		} else {
-			*p_context = context;
+		context->this = p_context;
+		context->task = task;
+		context->count = 0;
 
-			context->this = p_context;
-			context->task = task;
+		if (task)
+			set_tsk_thread_flag(task, TIF_DS_AREA_MSR);
 
-			if (task)
-				set_tsk_thread_flag(task, TIF_DS_AREA_MSR);
+		if (!task || (task == current))
+			wrmsrl(MSR_IA32_DS_AREA, (unsigned long)context->ds);
 
-			if (!task || (task == current))
-				wrmsrl(MSR_IA32_DS_AREA,
-				       (unsigned long)context->ds);
-		}
-		spin_unlock_irqrestore(&ds_lock, irq);
+		*p_context = context;
 	}
 
 	context->count++;
 
+	spin_unlock_irqrestore(&ds_lock, irq);
+
+	if (context != new_context)
+		kfree(new_context);
+
 	return context;
 }
 
-/*
- * Decreases the use count of the parameter context, if not NULL.
- * Deallocates the context, if the use count reaches zero.
- */
 static inline void ds_put_context(struct ds_context *context)
 {
 	unsigned long irq;
@@ -285,8 +284,10 @@ static inline void ds_put_context(struct ds_context *context)
 
 	spin_lock_irqsave(&ds_lock, irq);
 
-	if (--context->count)
-		goto out;
+	if (--context->count) {
+		spin_unlock_irqrestore(&ds_lock, irq);
+		return;
+	}
 
 	*(context->this) = NULL;
 
@@ -296,135 +297,263 @@ static inline void ds_put_context(struct ds_context *context)
 	if (!context->task || (context->task == current))
 		wrmsrl(MSR_IA32_DS_AREA, 0);
 
-	put_tracer(context->task);
+	spin_unlock_irqrestore(&ds_lock, irq);
 
-	/* free any leftover buffers from tracers that did not
-	 * deallocate them properly. */
-	kfree(context->buffer[ds_bts]);
-	kfree(context->buffer[ds_pebs]);
-	kfree(context->ds);
 	kfree(context);
- out:
-	spin_unlock_irqrestore(&ds_lock, irq);
 }
 
 
 /*
- * Handle a buffer overflow
+ * Call the tracer's callback on a buffer overflow.
  *
- * task: the task whose buffers are overflowing;
- *       NULL for a buffer overflow on the current cpu
  * context: the ds context
  * qual: the buffer type
  */
-static void ds_overflow(struct task_struct *task, struct ds_context *context,
-			enum ds_qualifier qual)
+static void ds_overflow(struct ds_context *context, enum ds_qualifier qual)
 {
-	if (!context)
-		return;
-
-	if (context->callback[qual])
-		(*context->callback[qual])(task);
-
-	/* todo: do some more overflow handling */
+	switch (qual) {
+	case ds_bts:
+		if (context->bts_master &&
+		    context->bts_master->ovfl)
+			context->bts_master->ovfl(context->bts_master);
+		break;
+	case ds_pebs:
+		if (context->pebs_master &&
+		    context->pebs_master->ovfl)
+			context->pebs_master->ovfl(context->pebs_master);
+		break;
+	}
 }
 
 
 /*
- * Allocate a non-pageable buffer of the parameter size.
- * Checks the memory and the locked memory rlimit.
+ * Write raw data into the BTS or PEBS buffer.
  *
- * Returns the buffer, if successful;
- *         NULL, if out of memory or rlimit exceeded.
+ * The remainder of any partially written record is zeroed out.
  *
- * size: the requested buffer size in bytes
- * pages (out): if not NULL, contains the number of pages reserved
+ * context: the DS context
+ * qual: the buffer type
+ * record: the data to write
+ * size: the size of the data
  */
-static inline void *ds_allocate_buffer(size_t size, unsigned int *pages)
+static int ds_write(struct ds_context *context, enum ds_qualifier qual,
+		    const void *record, size_t size)
 {
-	unsigned long rlim, vm, pgsz;
-	void *buffer;
+	int bytes_written = 0;
 
-	pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	if (!record)
+		return -EINVAL;
 
-	rlim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
-	vm   = current->mm->total_vm  + pgsz;
-	if (rlim < vm)
-		return NULL;
+	while (size) {
+		unsigned long base, index, end, write_end, int_th;
+		unsigned long write_size, adj_write_size;
 
-	rlim = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
-	vm   = current->mm->locked_vm  + pgsz;
-	if (rlim < vm)
-		return NULL;
+		/*
+		 * write as much as possible without producing an
+		 * overflow interrupt.
+		 *
+		 * interrupt_threshold must either be
+		 * - bigger than absolute_maximum or
+		 * - point to a record between buffer_base and absolute_maximum
+		 *
+		 * index points to a valid record.
+		 */
+		base   = ds_get(context->ds, qual, ds_buffer_base);
+		index  = ds_get(context->ds, qual, ds_index);
+		end    = ds_get(context->ds, qual, ds_absolute_maximum);
+		int_th = ds_get(context->ds, qual, ds_interrupt_threshold);
 
-	buffer = kzalloc(size, GFP_KERNEL);
-	if (!buffer)
-		return NULL;
+		write_end = min(end, int_th);
 
-	current->mm->total_vm  += pgsz;
-	current->mm->locked_vm += pgsz;
+		/* if we are already beyond the interrupt threshold,
+		 * we fill the entire buffer */
+		if (write_end <= index)
+			write_end = end;
 
-	if (pages)
-		*pages = pgsz;
+		if (write_end <= index)
+			break;
+
+		write_size = min((unsigned long) size, write_end - index);
+		memcpy((void *)index, record, write_size);
+
+		record = (const char *)record + write_size;
+		size -= write_size;
+		bytes_written += write_size;
+
+		adj_write_size = write_size / ds_cfg.sizeof_rec[qual];
+		adj_write_size *= ds_cfg.sizeof_rec[qual];
 
-	return buffer;
+		/* zero out trailing bytes */
+		memset((char *)index + write_size, 0,
+		       adj_write_size - write_size);
+		index += adj_write_size;
+
+		if (index >= end)
+			index = base;
+		ds_set(context->ds, qual, ds_index, index);
+
+		if (index >= int_th)
+			ds_overflow(context, qual);
+	}
+
+	return bytes_written;
 }
 
-static int ds_request(struct task_struct *task, void *base, size_t size,
-		      ds_ovfl_callback_t ovfl, enum ds_qualifier qual)
+
+/*
+ * Branch Trace Store (BTS) uses the following format. Different
+ * architectures vary in the size of those fields.
+ * - source linear address
+ * - destination linear address
+ * - flags
+ *
+ * Later architectures use 64bit pointers throughout, whereas earlier
+ * architectures use 32bit pointers in 32bit mode.
+ *
+ * We compute the base address for the first 8 fields based on:
+ * - the field size stored in the DS configuration
+ * - the relative field position
+ *
+ * In order to store additional information in the BTS buffer, we use
+ * a special source address to indicate that the record requires
+ * special interpretation.
+ *
+ * Netburst indicated via a bit in the flags field whether the branch
+ * was predicted; this is ignored.
+ *
+ * We use two levels of abstraction:
+ * - the raw data level defined here
+ * - an arch-independent level defined in ds.h
+ */
+
+enum bts_field {
+	bts_from,
+	bts_to,
+	bts_flags,
+
+	bts_qual = bts_from,
+	bts_jiffies = bts_to,
+	bts_pid = bts_flags,
+
+	bts_qual_mask = (bts_qual_max - 1),
+	bts_escape = ((unsigned long)-1 & ~bts_qual_mask)
+};
+
+static inline unsigned long bts_get(const char *base, enum bts_field field)
 {
-	struct ds_context *context;
-	unsigned long buffer, adj;
-	const unsigned long alignment = (1 << 3);
-	unsigned long irq;
-	int error = 0;
+	base += (ds_cfg.sizeof_field * field);
+	return *(unsigned long *)base;
+}
 
-	if (!ds_cfg.sizeof_ds)
-		return -EOPNOTSUPP;
+static inline void bts_set(char *base, enum bts_field field, unsigned long val)
+{
+	base += (ds_cfg.sizeof_field * field);;
+	(*(unsigned long *)base) = val;
+}
 
-	/* we require some space to do alignment adjustments below */
-	if (size < (alignment + ds_cfg.sizeof_rec[qual]))
+
+/*
+ * The raw BTS data is architecture dependent.
+ *
+ * For higher-level users, we give an arch-independent view.
+ * - ds.h defines struct bts_struct
+ * - bts_read translates one raw bts record into a bts_struct
+ * - bts_write translates one bts_struct into the raw format and
+ *   writes it into the top of the parameter tracer's buffer.
+ *
+ * return: bytes read/written on success; -Eerrno, otherwise
+ */
+static int bts_read(struct bts_tracer *tracer, const void *at,
+		    struct bts_struct *out)
+{
+	if (!tracer)
 		return -EINVAL;
 
-	/* buffer overflow notification is not yet implemented */
-	if (ovfl)
-		return -EOPNOTSUPP;
+	if (at < tracer->trace.ds.begin)
+		return -EINVAL;
 
+	if (tracer->trace.ds.end < (at + tracer->trace.ds.size))
+		return -EINVAL;
 
-	context = ds_alloc_context(task);
-	if (!context)
-		return -ENOMEM;
+	memset(out, 0, sizeof(*out));
+	if ((bts_get(at, bts_qual) & ~bts_qual_mask) == bts_escape) {
+		out->qualifier = (bts_get(at, bts_qual) & bts_qual_mask);
+		out->variant.timestamp.jiffies = bts_get(at, bts_jiffies);
+		out->variant.timestamp.pid = bts_get(at, bts_pid);
+	} else {
+		out->qualifier = bts_branch;
+		out->variant.lbr.from = bts_get(at, bts_from);
+		out->variant.lbr.to   = bts_get(at, bts_to);
+
+		if (!out->variant.lbr.from && !out->variant.lbr.to)
+			out->qualifier = bts_invalid;
+	}
 
-	spin_lock_irqsave(&ds_lock, irq);
+	return ds_cfg.sizeof_rec[ds_bts];
+}
 
-	error = -EPERM;
-	if (!check_tracer(task))
-		goto out_unlock;
+static int bts_write(struct bts_tracer *tracer, const struct bts_struct *in)
+{
+	unsigned char raw[MAX_SIZEOF_BTS];
 
-	get_tracer(task);
+	if (!tracer)
+		return -EINVAL;
 
-	error = -EALREADY;
-	if (context->owner[qual] == current)
-		goto out_put_tracer;
-	error = -EPERM;
-	if (context->owner[qual] != NULL)
-		goto out_put_tracer;
-	context->owner[qual] = current;
+	if (MAX_SIZEOF_BTS < ds_cfg.sizeof_rec[ds_bts])
+		return -EOVERFLOW;
 
-	spin_unlock_irqrestore(&ds_lock, irq);
+	switch (in->qualifier) {
+	case bts_invalid:
+		bts_set(raw, bts_from, 0);
+		bts_set(raw, bts_to, 0);
+		bts_set(raw, bts_flags, 0);
+		break;
+	case bts_branch:
+		bts_set(raw, bts_from, in->variant.lbr.from);
+		bts_set(raw, bts_to,   in->variant.lbr.to);
+		bts_set(raw, bts_flags, 0);
+		break;
+	case bts_task_arrives:
+	case bts_task_departs:
+		bts_set(raw, bts_qual, (bts_escape | in->qualifier));
+		bts_set(raw, bts_jiffies, in->variant.timestamp.jiffies);
+		bts_set(raw, bts_pid, in->variant.timestamp.pid);
+		break;
+	default:
+		return -EINVAL;
+	}
 
+	return ds_write(tracer->ds.context, ds_bts, raw,
+			ds_cfg.sizeof_rec[ds_bts]);
+}
 
-	error = -ENOMEM;
-	if (!base) {
-		base = ds_allocate_buffer(size, &context->pages[qual]);
-		if (!base)
-			goto out_release;
 
-		context->buffer[qual]   = base;
-	}
-	error = 0;
+static void ds_write_config(struct ds_context *context,
+			    struct ds_trace *cfg, enum ds_qualifier qual)
+{
+	unsigned char *ds = context->ds;
 
-	context->callback[qual] = ovfl;
+	ds_set(ds, qual, ds_buffer_base, (unsigned long)cfg->begin);
+	ds_set(ds, qual, ds_index, (unsigned long)cfg->top);
+	ds_set(ds, qual, ds_absolute_maximum, (unsigned long)cfg->end);
+	ds_set(ds, qual, ds_interrupt_threshold, (unsigned long)cfg->ith);
+}
+
+static void ds_read_config(struct ds_context *context,
+			   struct ds_trace *cfg, enum ds_qualifier qual)
+{
+	unsigned char *ds = context->ds;
+
+	cfg->begin = (void *)ds_get(ds, qual, ds_buffer_base);
+	cfg->top = (void *)ds_get(ds, qual, ds_index);
+	cfg->end = (void *)ds_get(ds, qual, ds_absolute_maximum);
+	cfg->ith = (void *)ds_get(ds, qual, ds_interrupt_threshold);
+}
+
+static void ds_init_ds_trace(struct ds_trace *trace, enum ds_qualifier qual,
+			     void *base, size_t size, size_t ith,
+			     unsigned int flags) {
+	unsigned long buffer, adj;
 
 	/* adjust the buffer address and size to meet alignment
 	 * constraints:
@@ -436,410 +565,383 @@ static int ds_request(struct task_struct *task, void *base, size_t size,
 	 */
 	buffer = (unsigned long)base;
 
-	adj = ALIGN(buffer, alignment) - buffer;
+	adj = ALIGN(buffer, DS_ALIGNMENT) - buffer;
 	buffer += adj;
 	size   -= adj;
 
-	size /= ds_cfg.sizeof_rec[qual];
-	size *= ds_cfg.sizeof_rec[qual];
-
-	ds_set(context->ds, qual, ds_buffer_base, buffer);
-	ds_set(context->ds, qual, ds_index, buffer);
-	ds_set(context->ds, qual, ds_absolute_maximum, buffer + size);
-
-	if (ovfl) {
-		/* todo: select a suitable interrupt threshold */
-	} else
-		ds_set(context->ds, qual,
-		       ds_interrupt_threshold, buffer + size + 1);
+	trace->n = size / ds_cfg.sizeof_rec[qual];
+	trace->size = ds_cfg.sizeof_rec[qual];
 
-	/* we keep the context until ds_release */
-	return error;
-
- out_release:
-	context->owner[qual] = NULL;
-	ds_put_context(context);
-	put_tracer(task);
-	return error;
+	size = (trace->n * trace->size);
 
- out_put_tracer:
-	spin_unlock_irqrestore(&ds_lock, irq);
-	ds_put_context(context);
-	put_tracer(task);
-	return error;
+	trace->begin = (void *)buffer;
+	trace->top = trace->begin;
+	trace->end = (void *)(buffer + size);
+	/* The value for 'no threshold' is -1, which will set the
+	 * threshold outside of the buffer, just like we want it.
+	 */
+	trace->ith = (void *)(buffer + size - ith);
 
- out_unlock:
-	spin_unlock_irqrestore(&ds_lock, irq);
-	ds_put_context(context);
-	return error;
+	trace->flags = flags;
 }
 
-int ds_request_bts(struct task_struct *task, void *base, size_t size,
-		   ds_ovfl_callback_t ovfl)
-{
-	return ds_request(task, base, size, ovfl, ds_bts);
-}
 
-int ds_request_pebs(struct task_struct *task, void *base, size_t size,
-		    ds_ovfl_callback_t ovfl)
-{
-	return ds_request(task, base, size, ovfl, ds_pebs);
-}
-
-static int ds_release(struct task_struct *task, enum ds_qualifier qual)
+static int ds_request(struct ds_tracer *tracer, struct ds_trace *trace,
+		      enum ds_qualifier qual, struct task_struct *task,
+		      void *base, size_t size, size_t th, unsigned int flags)
 {
 	struct ds_context *context;
 	int error;
 
-	context = ds_get_context(task);
-	error = ds_validate_access(context, qual);
-	if (error < 0)
+	error = -EINVAL;
+	if (!base)
 		goto out;
 
-	kfree(context->buffer[qual]);
-	context->buffer[qual] = NULL;
-
-	current->mm->total_vm  -= context->pages[qual];
-	current->mm->locked_vm -= context->pages[qual];
-	context->pages[qual] = 0;
-	context->owner[qual] = NULL;
-
-	/*
-	 * we put the context twice:
-	 *   once for the ds_get_context
-	 *   once for the corresponding ds_request
-	 */
-	ds_put_context(context);
- out:
-	ds_put_context(context);
-	return error;
-}
+	/* we require some space to do alignment adjustments below */
+	error = -EINVAL;
+	if (size < (DS_ALIGNMENT + ds_cfg.sizeof_rec[qual]))
+		goto out;
 
-int ds_release_bts(struct task_struct *task)
-{
-	return ds_release(task, ds_bts);
-}
+	if (th != (size_t)-1) {
+		th *= ds_cfg.sizeof_rec[qual];
 
-int ds_release_pebs(struct task_struct *task)
-{
-	return ds_release(task, ds_pebs);
-}
+		error = -EINVAL;
+		if (size <= th)
+			goto out;
+	}
 
-static int ds_get_index(struct task_struct *task, size_t *pos,
-			enum ds_qualifier qual)
-{
-	struct ds_context *context;
-	unsigned long base, index;
-	int error;
+	tracer->buffer = base;
+	tracer->size = size;
 
+	error = -ENOMEM;
 	context = ds_get_context(task);
-	error = ds_validate_access(context, qual);
-	if (error < 0)
+	if (!context)
 		goto out;
+	tracer->context = context;
 
-	base  = ds_get(context->ds, qual, ds_buffer_base);
-	index = ds_get(context->ds, qual, ds_index);
+	ds_init_ds_trace(trace, qual, base, size, th, flags);
 
-	error = ((index - base) / ds_cfg.sizeof_rec[qual]);
-	if (pos)
-		*pos = error;
+	error = 0;
  out:
-	ds_put_context(context);
 	return error;
 }
 
-int ds_get_bts_index(struct task_struct *task, size_t *pos)
-{
-	return ds_get_index(task, pos, ds_bts);
-}
-
-int ds_get_pebs_index(struct task_struct *task, size_t *pos)
-{
-	return ds_get_index(task, pos, ds_pebs);
-}
-
-static int ds_get_end(struct task_struct *task, size_t *pos,
-		      enum ds_qualifier qual)
+struct bts_tracer *ds_request_bts(struct task_struct *task,
+				  void *base, size_t size,
+				  bts_ovfl_callback_t ovfl, size_t th,
+				  unsigned int flags)
 {
-	struct ds_context *context;
-	unsigned long base, end;
+	struct bts_tracer *tracer;
+	unsigned long irq;
 	int error;
 
-	context = ds_get_context(task);
-	error = ds_validate_access(context, qual);
-	if (error < 0)
+	error = -EOPNOTSUPP;
+	if (!ds_cfg.ctl[dsf_bts])
 		goto out;
 
-	base = ds_get(context->ds, qual, ds_buffer_base);
-	end  = ds_get(context->ds, qual, ds_absolute_maximum);
+	/* buffer overflow notification is not yet implemented */
+	error = -EOPNOTSUPP;
+	if (ovfl)
+		goto out;
 
-	error = ((end - base) / ds_cfg.sizeof_rec[qual]);
-	if (pos)
-		*pos = error;
- out:
-	ds_put_context(context);
-	return error;
-}
+	error = -ENOMEM;
+	tracer = kzalloc(sizeof(*tracer), GFP_KERNEL);
+	if (!tracer)
+		goto out;
+	tracer->ovfl = ovfl;
 
-int ds_get_bts_end(struct task_struct *task, size_t *pos)
-{
-	return ds_get_end(task, pos, ds_bts);
-}
+	error = ds_request(&tracer->ds, &tracer->trace.ds,
+			   ds_bts, task, base, size, th, flags);
+	if (error < 0)
+		goto out_tracer;
 
-int ds_get_pebs_end(struct task_struct *task, size_t *pos)
-{
-	return ds_get_end(task, pos, ds_pebs);
-}
 
-static int ds_access(struct task_struct *task, size_t index,
-		     const void **record, enum ds_qualifier qual)
-{
-	struct ds_context *context;
-	unsigned long base, idx;
-	int error;
+	spin_lock_irqsave(&ds_lock, irq);
 
-	if (!record)
-		return -EINVAL;
+	error = -EPERM;
+	if (!check_tracer(task))
+		goto out_unlock;
+	get_tracer(task);
 
-	context = ds_get_context(task);
-	error = ds_validate_access(context, qual);
-	if (error < 0)
-		goto out;
+	error = -EPERM;
+	if (tracer->ds.context->bts_master)
+		goto out_put_tracer;
+	tracer->ds.context->bts_master = tracer;
 
-	base = ds_get(context->ds, qual, ds_buffer_base);
-	idx = base + (index * ds_cfg.sizeof_rec[qual]);
+	spin_unlock_irqrestore(&ds_lock, irq);
 
-	error = -EINVAL;
-	if (idx > ds_get(context->ds, qual, ds_absolute_maximum))
-		goto out;
 
-	*record = (const void *)idx;
-	error = ds_cfg.sizeof_rec[qual];
- out:
-	ds_put_context(context);
-	return error;
-}
+	tracer->trace.read  = bts_read;
+	tracer->trace.write = bts_write;
 
-int ds_access_bts(struct task_struct *task, size_t index, const void **record)
-{
-	return ds_access(task, index, record, ds_bts);
-}
+	ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_bts);
+	ds_resume_bts(tracer);
 
-int ds_access_pebs(struct task_struct *task, size_t index, const void **record)
-{
-	return ds_access(task, index, record, ds_pebs);
+	return tracer;
+
+ out_put_tracer:
+	put_tracer(task);
+ out_unlock:
+	spin_unlock_irqrestore(&ds_lock, irq);
+	ds_put_context(tracer->ds.context);
+ out_tracer:
+	kfree(tracer);
+ out:
+	return ERR_PTR(error);
 }
 
-static int ds_write(struct task_struct *task, const void *record, size_t size,
-		    enum ds_qualifier qual, int force)
+struct pebs_tracer *ds_request_pebs(struct task_struct *task,
+				    void *base, size_t size,
+				    pebs_ovfl_callback_t ovfl, size_t th,
+				    unsigned int flags)
 {
-	struct ds_context *context;
+	struct pebs_tracer *tracer;
+	unsigned long irq;
 	int error;
 
-	if (!record)
-		return -EINVAL;
+	/* buffer overflow notification is not yet implemented */
+	error = -EOPNOTSUPP;
+	if (ovfl)
+		goto out;
 
-	error = -EPERM;
-	context = ds_get_context(task);
-	if (!context)
+	error = -ENOMEM;
+	tracer = kzalloc(sizeof(*tracer), GFP_KERNEL);
+	if (!tracer)
 		goto out;
+	tracer->ovfl = ovfl;
 
-	if (!force) {
-		error = ds_validate_access(context, qual);
-		if (error < 0)
-			goto out;
-	}
+	error = ds_request(&tracer->ds, &tracer->trace.ds,
+			   ds_pebs, task, base, size, th, flags);
+	if (error < 0)
+		goto out_tracer;
 
-	error = 0;
-	while (size) {
-		unsigned long base, index, end, write_end, int_th;
-		unsigned long write_size, adj_write_size;
+	spin_lock_irqsave(&ds_lock, irq);
 
-		/*
-		 * write as much as possible without producing an
-		 * overflow interrupt.
-		 *
-		 * interrupt_threshold must either be
-		 * - bigger than absolute_maximum or
-		 * - point to a record between buffer_base and absolute_maximum
-		 *
-		 * index points to a valid record.
-		 */
-		base   = ds_get(context->ds, qual, ds_buffer_base);
-		index  = ds_get(context->ds, qual, ds_index);
-		end    = ds_get(context->ds, qual, ds_absolute_maximum);
-		int_th = ds_get(context->ds, qual, ds_interrupt_threshold);
+	error = -EPERM;
+	if (!check_tracer(task))
+		goto out_unlock;
+	get_tracer(task);
 
-		write_end = min(end, int_th);
+	error = -EPERM;
+	if (tracer->ds.context->pebs_master)
+		goto out_put_tracer;
+	tracer->ds.context->pebs_master = tracer;
 
-		/* if we are already beyond the interrupt threshold,
-		 * we fill the entire buffer */
-		if (write_end <= index)
-			write_end = end;
+	spin_unlock_irqrestore(&ds_lock, irq);
 
-		if (write_end <= index)
-			goto out;
+	ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_bts);
+	ds_resume_pebs(tracer);
 
-		write_size = min((unsigned long) size, write_end - index);
-		memcpy((void *)index, record, write_size);
+	return tracer;
 
-		record = (const char *)record + write_size;
-		size  -= write_size;
-		error += write_size;
+ out_put_tracer:
+	put_tracer(task);
+ out_unlock:
+	spin_unlock_irqrestore(&ds_lock, irq);
+	ds_put_context(tracer->ds.context);
+ out_tracer:
+	kfree(tracer);
+ out:
+	return ERR_PTR(error);
+}
 
-		adj_write_size = write_size / ds_cfg.sizeof_rec[qual];
-		adj_write_size *= ds_cfg.sizeof_rec[qual];
+void ds_release_bts(struct bts_tracer *tracer)
+{
+	if (!tracer)
+		return;
 
-		/* zero out trailing bytes */
-		memset((char *)index + write_size, 0,
-		       adj_write_size - write_size);
-		index += adj_write_size;
+	ds_suspend_bts(tracer);
 
-		if (index >= end)
-			index = base;
-		ds_set(context->ds, qual, ds_index, index);
+	WARN_ON_ONCE(tracer->ds.context->bts_master != tracer);
+	tracer->ds.context->bts_master = NULL;
 
-		if (index >= int_th)
-			ds_overflow(task, context, qual);
-	}
+	put_tracer(tracer->ds.context->task);
+	ds_put_context(tracer->ds.context);
 
- out:
-	ds_put_context(context);
-	return error;
+	kfree(tracer);
 }
 
-int ds_write_bts(struct task_struct *task, const void *record, size_t size)
+void ds_suspend_bts(struct bts_tracer *tracer)
 {
-	return ds_write(task, record, size, ds_bts, /* force = */ 0);
-}
+	struct task_struct *task;
 
-int ds_write_pebs(struct task_struct *task, const void *record, size_t size)
-{
-	return ds_write(task, record, size, ds_pebs, /* force = */ 0);
-}
+	if (!tracer)
+		return;
 
-int ds_unchecked_write_bts(struct task_struct *task,
-			   const void *record, size_t size)
-{
-	return ds_write(task, record, size, ds_bts, /* force = */ 1);
-}
+	task = tracer->ds.context->task;
 
-int ds_unchecked_write_pebs(struct task_struct *task,
-			    const void *record, size_t size)
-{
-	return ds_write(task, record, size, ds_pebs, /* force = */ 1);
+	if (!task || (task == current))
+		update_debugctlmsr(get_debugctlmsr() & ~BTS_CONTROL);
+
+	if (task) {
+		task->thread.debugctlmsr &= ~BTS_CONTROL;
+
+		if (!task->thread.debugctlmsr)
+			clear_tsk_thread_flag(task, TIF_DEBUGCTLMSR);
+	}
 }
 
-static int ds_reset_or_clear(struct task_struct *task,
-			     enum ds_qualifier qual, int clear)
+void ds_resume_bts(struct bts_tracer *tracer)
 {
-	struct ds_context *context;
-	unsigned long base, end;
-	int error;
+	struct task_struct *task;
+	unsigned long control;
 
-	context = ds_get_context(task);
-	error = ds_validate_access(context, qual);
-	if (error < 0)
-		goto out;
+	if (!tracer)
+		return;
 
-	base = ds_get(context->ds, qual, ds_buffer_base);
-	end  = ds_get(context->ds, qual, ds_absolute_maximum);
+	task = tracer->ds.context->task;
 
-	if (clear)
-		memset((void *)base, 0, end - base);
+	control = ds_cfg.ctl[dsf_bts];
+	if (!(tracer->trace.ds.flags & BTS_KERNEL))
+		control |= ds_cfg.ctl[dsf_bts_kernel];
+	if (!(tracer->trace.ds.flags & BTS_USER))
+		control |= ds_cfg.ctl[dsf_bts_user];
 
-	ds_set(context->ds, qual, ds_index, base);
+	if (task) {
+		task->thread.debugctlmsr |= control;
+		set_tsk_thread_flag(task, TIF_DEBUGCTLMSR);
+	}
 
-	error = 0;
- out:
-	ds_put_context(context);
-	return error;
+	if (!task || (task == current))
+		update_debugctlmsr(get_debugctlmsr() | control);
 }
 
-int ds_reset_bts(struct task_struct *task)
+void ds_release_pebs(struct pebs_tracer *tracer)
 {
-	return ds_reset_or_clear(task, ds_bts, /* clear = */ 0);
+	if (!tracer)
+		return;
+
+	ds_suspend_pebs(tracer);
+
+	WARN_ON_ONCE(tracer->ds.context->pebs_master != tracer);
+	tracer->ds.context->pebs_master = NULL;
+
+	put_tracer(tracer->ds.context->task);
+	ds_put_context(tracer->ds.context);
+
+	kfree(tracer);
 }
 
-int ds_reset_pebs(struct task_struct *task)
+void ds_suspend_pebs(struct pebs_tracer *tracer)
 {
-	return ds_reset_or_clear(task, ds_pebs, /* clear = */ 0);
+
 }
 
-int ds_clear_bts(struct task_struct *task)
+void ds_resume_pebs(struct pebs_tracer *tracer)
 {
-	return ds_reset_or_clear(task, ds_bts, /* clear = */ 1);
+
 }
 
-int ds_clear_pebs(struct task_struct *task)
+const struct bts_trace *ds_read_bts(struct bts_tracer *tracer)
 {
-	return ds_reset_or_clear(task, ds_pebs, /* clear = */ 1);
+	if (!tracer)
+		return NULL;
+
+	ds_read_config(tracer->ds.context, &tracer->trace.ds, ds_bts);
+	return &tracer->trace;
 }
 
-int ds_get_pebs_reset(struct task_struct *task, u64 *value)
+const struct pebs_trace *ds_read_pebs(struct pebs_tracer *tracer)
 {
-	struct ds_context *context;
-	int error;
+	if (!tracer)
+		return NULL;
 
-	if (!value)
+	ds_read_config(tracer->ds.context, &tracer->trace.ds, ds_pebs);
+	tracer->trace.reset_value =
+		*(u64 *)(tracer->ds.context->ds + (ds_cfg.sizeof_field * 8));
+
+	return &tracer->trace;
+}
+
+int ds_reset_bts(struct bts_tracer *tracer)
+{
+	if (!tracer)
 		return -EINVAL;
 
-	context = ds_get_context(task);
-	error = ds_validate_access(context, ds_pebs);
-	if (error < 0)
-		goto out;
+	tracer->trace.ds.top = tracer->trace.ds.begin;
 
-	*value = *(u64 *)(context->ds + (ds_cfg.sizeof_field * 8));
+	ds_set(tracer->ds.context->ds, ds_bts, ds_index,
+	       (unsigned long)tracer->trace.ds.top);
 
-	error = 0;
- out:
-	ds_put_context(context);
-	return error;
+	return 0;
 }
 
-int ds_set_pebs_reset(struct task_struct *task, u64 value)
+int ds_reset_pebs(struct pebs_tracer *tracer)
 {
-	struct ds_context *context;
-	int error;
+	if (!tracer)
+		return -EINVAL;
 
-	context = ds_get_context(task);
-	error = ds_validate_access(context, ds_pebs);
-	if (error < 0)
-		goto out;
+	tracer->trace.ds.top = tracer->trace.ds.begin;
 
-	*(u64 *)(context->ds + (ds_cfg.sizeof_field * 8)) = value;
+	ds_set(tracer->ds.context->ds, ds_bts, ds_index,
+	       (unsigned long)tracer->trace.ds.top);
 
-	error = 0;
- out:
-	ds_put_context(context);
-	return error;
+	return 0;
+}
+
+int ds_set_pebs_reset(struct pebs_tracer *tracer, u64 value)
+{
+	if (!tracer)
+		return -EINVAL;
+
+	*(u64 *)(tracer->ds.context->ds + (ds_cfg.sizeof_field * 8)) = value;
+
+	return 0;
 }
 
-static const struct ds_configuration ds_cfg_var = {
-	.sizeof_ds    = sizeof(long) * 12,
-	.sizeof_field = sizeof(long),
-	.sizeof_rec[ds_bts]   = sizeof(long) * 3,
+static const struct ds_configuration ds_cfg_netburst = {
+	.name = "netburst",
+	.ctl[dsf_bts]		= (1 << 2) | (1 << 3),
+	.ctl[dsf_bts_kernel]	= (1 << 5),
+	.ctl[dsf_bts_user]	= (1 << 6),
+
+	.sizeof_field		= sizeof(long),
+	.sizeof_rec[ds_bts]	= sizeof(long) * 3,
 #ifdef __i386__
-	.sizeof_rec[ds_pebs]  = sizeof(long) * 10
+	.sizeof_rec[ds_pebs]	= sizeof(long) * 10,
 #else
-	.sizeof_rec[ds_pebs]  = sizeof(long) * 18
+	.sizeof_rec[ds_pebs]	= sizeof(long) * 18,
 #endif
 };
-static const struct ds_configuration ds_cfg_64 = {
-	.sizeof_ds    = 8 * 12,
-	.sizeof_field = 8,
-	.sizeof_rec[ds_bts]   = 8 * 3,
+static const struct ds_configuration ds_cfg_pentium_m = {
+	.name = "pentium m",
+	.ctl[dsf_bts]		= (1 << 6) | (1 << 7),
+
+	.sizeof_field		= sizeof(long),
+	.sizeof_rec[ds_bts]	= sizeof(long) * 3,
 #ifdef __i386__
-	.sizeof_rec[ds_pebs]  = 8 * 10
+	.sizeof_rec[ds_pebs]	= sizeof(long) * 10,
 #else
-	.sizeof_rec[ds_pebs]  = 8 * 18
+	.sizeof_rec[ds_pebs]	= sizeof(long) * 18,
 #endif
 };
+static const struct ds_configuration ds_cfg_core2 = {
+	.name = "core 2",
+	.ctl[dsf_bts]		= (1 << 6) | (1 << 7),
+	.ctl[dsf_bts_kernel]	= (1 << 9),
+	.ctl[dsf_bts_user]	= (1 << 10),
+
+	.sizeof_field		= 8,
+	.sizeof_rec[ds_bts]	= 8 * 3,
+	.sizeof_rec[ds_pebs]	= 8 * 18,
+};
 
-static inline void
+static void
 ds_configure(const struct ds_configuration *cfg)
 {
+	memset(&ds_cfg, 0, sizeof(ds_cfg));
 	ds_cfg = *cfg;
+
+	printk(KERN_INFO "[ds] using %s configuration\n", ds_cfg.name);
+
+	if (!cpu_has_bts) {
+		ds_cfg.ctl[dsf_bts] = 0;
+		printk(KERN_INFO "[ds] bts not available\n");
+	}
+	if (!cpu_has_pebs)
+		printk(KERN_INFO "[ds] pebs not available\n");
+
+	WARN_ON_ONCE(MAX_SIZEOF_DS < (12 * ds_cfg.sizeof_field));
 }
 
 void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)
@@ -852,10 +954,10 @@ void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)
 			break;
 		case 0xD:
 		case 0xE: /* Pentium M */
-			ds_configure(&ds_cfg_var);
+			ds_configure(&ds_cfg_pentium_m);
 			break;
 		default: /* Core2, Atom, ... */
-			ds_configure(&ds_cfg_64);
+			ds_configure(&ds_cfg_core2);
 			break;
 		}
 		break;
@@ -864,7 +966,7 @@ void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)
 		case 0x0:
 		case 0x1:
 		case 0x2: /* Netburst */
-			ds_configure(&ds_cfg_var);
+			ds_configure(&ds_cfg_netburst);
 			break;
 		default:
 			/* sorry, don't know about them */
@@ -877,12 +979,52 @@ void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)
 	}
 }
 
-void ds_free(struct ds_context *context)
+/*
+ * Change the DS configuration from tracing prev to tracing next.
+ */
+void ds_switch_to(struct task_struct *prev, struct task_struct *next)
+{
+	struct ds_context *prev_ctx = prev->thread.ds_ctx;
+	struct ds_context *next_ctx = next->thread.ds_ctx;
+
+	if (prev_ctx) {
+		update_debugctlmsr(0);
+
+		if (prev_ctx->bts_master &&
+		    (prev_ctx->bts_master->trace.ds.flags & BTS_TIMESTAMPS)) {
+			struct bts_struct ts = {
+				.qualifier = bts_task_departs,
+				.variant.timestamp.jiffies = jiffies_64,
+				.variant.timestamp.pid = prev->pid
+			};
+			bts_write(prev_ctx->bts_master, &ts);
+		}
+	}
+
+	if (next_ctx) {
+		if (next_ctx->bts_master &&
+		    (next_ctx->bts_master->trace.ds.flags & BTS_TIMESTAMPS)) {
+			struct bts_struct ts = {
+				.qualifier = bts_task_arrives,
+				.variant.timestamp.jiffies = jiffies_64,
+				.variant.timestamp.pid = next->pid
+			};
+			bts_write(next_ctx->bts_master, &ts);
+		}
+
+		wrmsrl(MSR_IA32_DS_AREA, (unsigned long)next_ctx->ds);
+	}
+
+	update_debugctlmsr(next->thread.debugctlmsr);
+}
+
+void ds_copy_thread(struct task_struct *tsk, struct task_struct *father)
+{
+	clear_tsk_thread_flag(tsk, TIF_DS_AREA_MSR);
+	tsk->thread.ds_ctx = NULL;
+}
+
+void ds_exit_thread(struct task_struct *tsk)
 {
-	/* This is called when the task owning the parameter context
-	 * is dying. There should not be any user of that context left
-	 * to disturb us, anymore. */
-	unsigned long leftovers = context->count;
-	while (leftovers--)
-		ds_put_context(context);
+	WARN_ON(tsk->thread.ds_ctx);
 }
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 5962176dfab..6b1f6f6f866 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -30,6 +30,37 @@ void printk_address(unsigned long address, int reliable)
 			reliable ? "" : "? ", (void *) address);
 }
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static void
+print_ftrace_graph_addr(unsigned long addr, void *data,
+			const struct stacktrace_ops *ops,
+			struct thread_info *tinfo, int *graph)
+{
+	struct task_struct *task = tinfo->task;
+	unsigned long ret_addr;
+	int index = task->curr_ret_stack;
+
+	if (addr != (unsigned long)return_to_handler)
+		return;
+
+	if (!task->ret_stack || index < *graph)
+		return;
+
+	index -= *graph;
+	ret_addr = task->ret_stack[index].ret;
+
+	ops->address(data, ret_addr, 1);
+
+	(*graph)++;
+}
+#else
+static inline void
+print_ftrace_graph_addr(unsigned long addr, void *data,
+			const struct stacktrace_ops *ops,
+			struct thread_info *tinfo, int *graph)
+{ }
+#endif
+
 /*
  * x86-64 can have up to three kernel stacks:
  * process stack
@@ -54,7 +85,7 @@ unsigned long
 print_context_stack(struct thread_info *tinfo,
 		unsigned long *stack, unsigned long bp,
 		const struct stacktrace_ops *ops, void *data,
-		unsigned long *end)
+		unsigned long *end, int *graph)
 {
 	struct stack_frame *frame = (struct stack_frame *)bp;
 
@@ -70,6 +101,7 @@ print_context_stack(struct thread_info *tinfo,
 			} else {
 				ops->address(data, addr, bp == 0);
 			}
+			print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
 		}
 		stack++;
 	}
diff --git a/arch/x86/kernel/dumpstack.h b/arch/x86/kernel/dumpstack.h
index 3119a801c32..da87590b869 100644
--- a/arch/x86/kernel/dumpstack.h
+++ b/arch/x86/kernel/dumpstack.h
@@ -18,7 +18,7 @@ extern unsigned long
 print_context_stack(struct thread_info *tinfo,
 		unsigned long *stack, unsigned long bp,
 		const struct stacktrace_ops *ops, void *data,
-		unsigned long *end);
+		unsigned long *end, int *graph);
 
 extern void
 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 7b031b106ec..d593cd1f58d 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -23,6 +23,8 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *stack, unsigned long bp,
 		const struct stacktrace_ops *ops, void *data)
 {
+	int graph = 0;
+
 	if (!task)
 		task = current;
 
@@ -50,7 +52,8 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 
 		context = (struct thread_info *)
 			((unsigned long)stack & (~(THREAD_SIZE - 1)));
-		bp = print_context_stack(context, stack, bp, ops, data, NULL);
+		bp = print_context_stack(context, stack, bp, ops,
+					 data, NULL, &graph);
 
 		stack = (unsigned long *)context->previous_esp;
 		if (!stack)
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 33ff10287a5..c302d070704 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -109,6 +109,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 	unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
 	unsigned used = 0;
 	struct thread_info *tinfo;
+	int graph = 0;
 
 	if (!task)
 		task = current;
@@ -149,7 +150,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 				break;
 
 			bp = print_context_stack(tinfo, stack, bp, ops,
-							data, estack_end);
+						 data, estack_end, &graph);
 			ops->stack(data, "<EOE>");
 			/*
 			 * We link to the next stack via the
@@ -168,7 +169,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 				if (ops->stack(data, "IRQ") < 0)
 					break;
 				bp = print_context_stack(tinfo, stack, bp,
-						ops, data, irqstack_end);
+					ops, data, irqstack_end, &graph);
 				/*
 				 * We link to the next stack (which would be
 				 * the process stack normally) the last
@@ -186,7 +187,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 	/*
 	 * This handles the process stack:
 	 */
-	bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);
+	bp = print_context_stack(tinfo, stack, bp, ops, data, NULL, &graph);
 	put_cpu();
 }
 EXPORT_SYMBOL(dump_trace);
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index fe7014176eb..d6f0490a739 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -954,6 +954,9 @@ ENTRY(mcount)
 END(mcount)
 
 ENTRY(ftrace_caller)
+	cmpl $0, function_trace_stop
+	jne  ftrace_stub
+
 	pushl %eax
 	pushl %ecx
 	pushl %edx
@@ -968,6 +971,11 @@ ftrace_call:
 	popl %edx
 	popl %ecx
 	popl %eax
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.globl ftrace_graph_call
+ftrace_graph_call:
+	jmp ftrace_stub
+#endif
 
 .globl ftrace_stub
 ftrace_stub:
@@ -977,8 +985,18 @@ END(ftrace_caller)
 #else /* ! CONFIG_DYNAMIC_FTRACE */
 
 ENTRY(mcount)
+	cmpl $0, function_trace_stop
+	jne  ftrace_stub
+
 	cmpl $ftrace_stub, ftrace_trace_function
 	jnz trace
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	cmpl $ftrace_stub, ftrace_graph_return
+	jnz ftrace_graph_caller
+
+	cmpl $ftrace_graph_entry_stub, ftrace_graph_entry
+	jnz ftrace_graph_caller
+#endif
 .globl ftrace_stub
 ftrace_stub:
 	ret
@@ -997,12 +1015,43 @@ trace:
 	popl %edx
 	popl %ecx
 	popl %eax
-
 	jmp ftrace_stub
 END(mcount)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 #endif /* CONFIG_FUNCTION_TRACER */
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
+	cmpl $0, function_trace_stop
+	jne ftrace_stub
+
+	pushl %eax
+	pushl %ecx
+	pushl %edx
+	movl 0xc(%esp), %edx
+	lea 0x4(%ebp), %eax
+	subl $MCOUNT_INSN_SIZE, %edx
+	call prepare_ftrace_return
+	popl %edx
+	popl %ecx
+	popl %eax
+	ret
+END(ftrace_graph_caller)
+
+.globl return_to_handler
+return_to_handler:
+	pushl $0
+	pushl %eax
+	pushl %ecx
+	pushl %edx
+	call ftrace_return_to_handler
+	movl %eax, 0xc(%esp)
+	popl %edx
+	popl %ecx
+	popl %eax
+	ret
+#endif
+
 .section .rodata,"a"
 #include "syscall_table_32.S"
 
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 3194636a429..e28c7a98779 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -67,16 +67,10 @@ ENTRY(mcount)
 END(mcount)
 
 ENTRY(ftrace_caller)
+	cmpl $0, function_trace_stop
+	jne  ftrace_stub
 
-	/* taken from glibc */
-	subq $0x38, %rsp
-	movq %rax, (%rsp)
-	movq %rcx, 8(%rsp)
-	movq %rdx, 16(%rsp)
-	movq %rsi, 24(%rsp)
-	movq %rdi, 32(%rsp)
-	movq %r8, 40(%rsp)
-	movq %r9, 48(%rsp)
+	MCOUNT_SAVE_FRAME
 
 	movq 0x38(%rsp), %rdi
 	movq 8(%rbp), %rsi
@@ -86,14 +80,13 @@ ENTRY(ftrace_caller)
 ftrace_call:
 	call ftrace_stub
 
-	movq 48(%rsp), %r9
-	movq 40(%rsp), %r8
-	movq 32(%rsp), %rdi
-	movq 24(%rsp), %rsi
-	movq 16(%rsp), %rdx
-	movq 8(%rsp), %rcx
-	movq (%rsp), %rax
-	addq $0x38, %rsp
+	MCOUNT_RESTORE_FRAME
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.globl ftrace_graph_call
+ftrace_graph_call:
+	jmp ftrace_stub
+#endif
 
 .globl ftrace_stub
 ftrace_stub:
@@ -102,15 +95,63 @@ END(ftrace_caller)
 
 #else /* ! CONFIG_DYNAMIC_FTRACE */
 ENTRY(mcount)
+	cmpl $0, function_trace_stop
+	jne  ftrace_stub
+
 	cmpq $ftrace_stub, ftrace_trace_function
 	jnz trace
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	cmpq $ftrace_stub, ftrace_graph_return
+	jnz ftrace_graph_caller
+
+	cmpq $ftrace_graph_entry_stub, ftrace_graph_entry
+	jnz ftrace_graph_caller
+#endif
+
 .globl ftrace_stub
 ftrace_stub:
 	retq
 
 trace:
-	/* taken from glibc */
-	subq $0x38, %rsp
+	MCOUNT_SAVE_FRAME
+
+	movq 0x38(%rsp), %rdi
+	movq 8(%rbp), %rsi
+	subq $MCOUNT_INSN_SIZE, %rdi
+
+	call   *ftrace_trace_function
+
+	MCOUNT_RESTORE_FRAME
+
+	jmp ftrace_stub
+END(mcount)
+#endif /* CONFIG_DYNAMIC_FTRACE */
+#endif /* CONFIG_FUNCTION_TRACER */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
+	cmpl $0, function_trace_stop
+	jne ftrace_stub
+
+	MCOUNT_SAVE_FRAME
+
+	leaq 8(%rbp), %rdi
+	movq 0x38(%rsp), %rsi
+	subq $MCOUNT_INSN_SIZE, %rsi
+
+	call	prepare_ftrace_return
+
+	MCOUNT_RESTORE_FRAME
+
+	retq
+END(ftrace_graph_caller)
+
+
+.globl return_to_handler
+return_to_handler:
+	subq  $80, %rsp
+
 	movq %rax, (%rsp)
 	movq %rcx, 8(%rsp)
 	movq %rdx, 16(%rsp)
@@ -118,13 +159,14 @@ trace:
 	movq %rdi, 32(%rsp)
 	movq %r8, 40(%rsp)
 	movq %r9, 48(%rsp)
+	movq %r10, 56(%rsp)
+	movq %r11, 64(%rsp)
 
-	movq 0x38(%rsp), %rdi
-	movq 8(%rbp), %rsi
-	subq $MCOUNT_INSN_SIZE, %rdi
-
-	call   *ftrace_trace_function
+	call ftrace_return_to_handler
 
+	movq %rax, 72(%rsp)
+	movq 64(%rsp), %r11
+	movq 56(%rsp), %r10
 	movq 48(%rsp), %r9
 	movq 40(%rsp), %r8
 	movq 32(%rsp), %rdi
@@ -132,12 +174,10 @@ trace:
 	movq 16(%rsp), %rdx
 	movq 8(%rsp), %rcx
 	movq (%rsp), %rax
-	addq $0x38, %rsp
+	addq $72, %rsp
+	retq
+#endif
 
-	jmp ftrace_stub
-END(mcount)
-#endif /* CONFIG_DYNAMIC_FTRACE */
-#endif /* CONFIG_FUNCTION_TRACER */
 
 #ifndef CONFIG_PREEMPT
 #define retint_kernel retint_restore_args
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 50ea0ac8c9b..1b43086b097 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -14,14 +14,17 @@
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
 #include <linux/percpu.h>
+#include <linux/sched.h>
 #include <linux/init.h>
 #include <linux/list.h>
 
 #include <asm/ftrace.h>
+#include <linux/ftrace.h>
 #include <asm/nops.h>
+#include <asm/nmi.h>
 
 
-static unsigned char ftrace_nop[MCOUNT_INSN_SIZE];
+#ifdef CONFIG_DYNAMIC_FTRACE
 
 union ftrace_code_union {
 	char code[MCOUNT_INSN_SIZE];
@@ -31,18 +34,12 @@ union ftrace_code_union {
 	} __attribute__((packed));
 };
 
-
 static int ftrace_calc_offset(long ip, long addr)
 {
 	return (int)(addr - ip);
 }
 
-unsigned char *ftrace_nop_replace(void)
-{
-	return ftrace_nop;
-}
-
-unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
+static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
 {
 	static union ftrace_code_union calc;
 
@@ -56,7 +53,142 @@ unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
 	return calc.code;
 }
 
-int
+/*
+ * Modifying code must take extra care. On an SMP machine, if
+ * the code being modified is also being executed on another CPU
+ * that CPU will have undefined results and possibly take a GPF.
+ * We use kstop_machine to stop other CPUS from exectuing code.
+ * But this does not stop NMIs from happening. We still need
+ * to protect against that. We separate out the modification of
+ * the code to take care of this.
+ *
+ * Two buffers are added: An IP buffer and a "code" buffer.
+ *
+ * 1) Put the instruction pointer into the IP buffer
+ *    and the new code into the "code" buffer.
+ * 2) Set a flag that says we are modifying code
+ * 3) Wait for any running NMIs to finish.
+ * 4) Write the code
+ * 5) clear the flag.
+ * 6) Wait for any running NMIs to finish.
+ *
+ * If an NMI is executed, the first thing it does is to call
+ * "ftrace_nmi_enter". This will check if the flag is set to write
+ * and if it is, it will write what is in the IP and "code" buffers.
+ *
+ * The trick is, it does not matter if everyone is writing the same
+ * content to the code location. Also, if a CPU is executing code
+ * it is OK to write to that code location if the contents being written
+ * are the same as what exists.
+ */
+
+static atomic_t in_nmi = ATOMIC_INIT(0);
+static int mod_code_status;		/* holds return value of text write */
+static int mod_code_write;		/* set when NMI should do the write */
+static void *mod_code_ip;		/* holds the IP to write to */
+static void *mod_code_newcode;		/* holds the text to write to the IP */
+
+static unsigned nmi_wait_count;
+static atomic_t nmi_update_count = ATOMIC_INIT(0);
+
+int ftrace_arch_read_dyn_info(char *buf, int size)
+{
+	int r;
+
+	r = snprintf(buf, size, "%u %u",
+		     nmi_wait_count,
+		     atomic_read(&nmi_update_count));
+	return r;
+}
+
+static void ftrace_mod_code(void)
+{
+	/*
+	 * Yes, more than one CPU process can be writing to mod_code_status.
+	 *    (and the code itself)
+	 * But if one were to fail, then they all should, and if one were
+	 * to succeed, then they all should.
+	 */
+	mod_code_status = probe_kernel_write(mod_code_ip, mod_code_newcode,
+					     MCOUNT_INSN_SIZE);
+}
+
+void ftrace_nmi_enter(void)
+{
+	atomic_inc(&in_nmi);
+	/* Must have in_nmi seen before reading write flag */
+	smp_mb();
+	if (mod_code_write) {
+		ftrace_mod_code();
+		atomic_inc(&nmi_update_count);
+	}
+}
+
+void ftrace_nmi_exit(void)
+{
+	/* Finish all executions before clearing in_nmi */
+	smp_wmb();
+	atomic_dec(&in_nmi);
+}
+
+static void wait_for_nmi(void)
+{
+	int waited = 0;
+
+	while (atomic_read(&in_nmi)) {
+		waited = 1;
+		cpu_relax();
+	}
+
+	if (waited)
+		nmi_wait_count++;
+}
+
+static int
+do_ftrace_mod_code(unsigned long ip, void *new_code)
+{
+	mod_code_ip = (void *)ip;
+	mod_code_newcode = new_code;
+
+	/* The buffers need to be visible before we let NMIs write them */
+	smp_wmb();
+
+	mod_code_write = 1;
+
+	/* Make sure write bit is visible before we wait on NMIs */
+	smp_mb();
+
+	wait_for_nmi();
+
+	/* Make sure all running NMIs have finished before we write the code */
+	smp_mb();
+
+	ftrace_mod_code();
+
+	/* Make sure the write happens before clearing the bit */
+	smp_wmb();
+
+	mod_code_write = 0;
+
+	/* make sure NMIs see the cleared bit */
+	smp_mb();
+
+	wait_for_nmi();
+
+	return mod_code_status;
+}
+
+
+
+
+static unsigned char ftrace_nop[MCOUNT_INSN_SIZE];
+
+static unsigned char *ftrace_nop_replace(void)
+{
+	return ftrace_nop;
+}
+
+static int
 ftrace_modify_code(unsigned long ip, unsigned char *old_code,
 		   unsigned char *new_code)
 {
@@ -81,7 +213,7 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
 		return -EINVAL;
 
 	/* replace the text with the new text */
-	if (probe_kernel_write((void *)ip, new_code, MCOUNT_INSN_SIZE))
+	if (do_ftrace_mod_code(ip, new_code))
 		return -EPERM;
 
 	sync_core();
@@ -89,6 +221,29 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
 	return 0;
 }
 
+int ftrace_make_nop(struct module *mod,
+		    struct dyn_ftrace *rec, unsigned long addr)
+{
+	unsigned char *new, *old;
+	unsigned long ip = rec->ip;
+
+	old = ftrace_call_replace(ip, addr);
+	new = ftrace_nop_replace();
+
+	return ftrace_modify_code(rec->ip, old, new);
+}
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+	unsigned char *new, *old;
+	unsigned long ip = rec->ip;
+
+	old = ftrace_nop_replace();
+	new = ftrace_call_replace(ip, addr);
+
+	return ftrace_modify_code(rec->ip, old, new);
+}
+
 int ftrace_update_ftrace_func(ftrace_func_t func)
 {
 	unsigned long ip = (unsigned long)(&ftrace_call);
@@ -165,3 +320,218 @@ int __init ftrace_dyn_arch_init(void *data)
 
 	return 0;
 }
+#endif
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern void ftrace_graph_call(void);
+
+static int ftrace_mod_jmp(unsigned long ip,
+			  int old_offset, int new_offset)
+{
+	unsigned char code[MCOUNT_INSN_SIZE];
+
+	if (probe_kernel_read(code, (void *)ip, MCOUNT_INSN_SIZE))
+		return -EFAULT;
+
+	if (code[0] != 0xe9 || old_offset != *(int *)(&code[1]))
+		return -EINVAL;
+
+	*(int *)(&code[1]) = new_offset;
+
+	if (do_ftrace_mod_code(ip, &code))
+		return -EPERM;
+
+	return 0;
+}
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+	unsigned long ip = (unsigned long)(&ftrace_graph_call);
+	int old_offset, new_offset;
+
+	old_offset = (unsigned long)(&ftrace_stub) - (ip + MCOUNT_INSN_SIZE);
+	new_offset = (unsigned long)(&ftrace_graph_caller) - (ip + MCOUNT_INSN_SIZE);
+
+	return ftrace_mod_jmp(ip, old_offset, new_offset);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+	unsigned long ip = (unsigned long)(&ftrace_graph_call);
+	int old_offset, new_offset;
+
+	old_offset = (unsigned long)(&ftrace_graph_caller) - (ip + MCOUNT_INSN_SIZE);
+	new_offset = (unsigned long)(&ftrace_stub) - (ip + MCOUNT_INSN_SIZE);
+
+	return ftrace_mod_jmp(ip, old_offset, new_offset);
+}
+
+#else /* CONFIG_DYNAMIC_FTRACE */
+
+/*
+ * These functions are picked from those used on
+ * this page for dynamic ftrace. They have been
+ * simplified to ignore all traces in NMI context.
+ */
+static atomic_t in_nmi;
+
+void ftrace_nmi_enter(void)
+{
+	atomic_inc(&in_nmi);
+}
+
+void ftrace_nmi_exit(void)
+{
+	atomic_dec(&in_nmi);
+}
+
+#endif /* !CONFIG_DYNAMIC_FTRACE */
+
+/* Add a function return address to the trace stack on thread info.*/
+static int push_return_trace(unsigned long ret, unsigned long long time,
+				unsigned long func, int *depth)
+{
+	int index;
+
+	if (!current->ret_stack)
+		return -EBUSY;
+
+	/* The return trace stack is full */
+	if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
+		atomic_inc(&current->trace_overrun);
+		return -EBUSY;
+	}
+
+	index = ++current->curr_ret_stack;
+	barrier();
+	current->ret_stack[index].ret = ret;
+	current->ret_stack[index].func = func;
+	current->ret_stack[index].calltime = time;
+	*depth = index;
+
+	return 0;
+}
+
+/* Retrieve a function return address to the trace stack on thread info.*/
+static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
+{
+	int index;
+
+	index = current->curr_ret_stack;
+
+	if (unlikely(index < 0)) {
+		ftrace_graph_stop();
+		WARN_ON(1);
+		/* Might as well panic, otherwise we have no where to go */
+		*ret = (unsigned long)panic;
+		return;
+	}
+
+	*ret = current->ret_stack[index].ret;
+	trace->func = current->ret_stack[index].func;
+	trace->calltime = current->ret_stack[index].calltime;
+	trace->overrun = atomic_read(&current->trace_overrun);
+	trace->depth = index;
+	barrier();
+	current->curr_ret_stack--;
+
+}
+
+/*
+ * Send the trace to the ring-buffer.
+ * @return the original return address.
+ */
+unsigned long ftrace_return_to_handler(void)
+{
+	struct ftrace_graph_ret trace;
+	unsigned long ret;
+
+	pop_return_trace(&trace, &ret);
+	trace.rettime = cpu_clock(raw_smp_processor_id());
+	ftrace_graph_return(&trace);
+
+	if (unlikely(!ret)) {
+		ftrace_graph_stop();
+		WARN_ON(1);
+		/* Might as well panic. What else to do? */
+		ret = (unsigned long)panic;
+	}
+
+	return ret;
+}
+
+/*
+ * Hook the return address and push it in the stack of return addrs
+ * in current thread info.
+ */
+void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
+{
+	unsigned long old;
+	unsigned long long calltime;
+	int faulted;
+	struct ftrace_graph_ent trace;
+	unsigned long return_hooker = (unsigned long)
+				&return_to_handler;
+
+	/* Nmi's are currently unsupported */
+	if (unlikely(atomic_read(&in_nmi)))
+		return;
+
+	if (unlikely(atomic_read(&current->tracing_graph_pause)))
+		return;
+
+	/*
+	 * Protect against fault, even if it shouldn't
+	 * happen. This tool is too much intrusive to
+	 * ignore such a protection.
+	 */
+	asm volatile(
+		"1: " _ASM_MOV " (%[parent_old]), %[old]\n"
+		"2: " _ASM_MOV " %[return_hooker], (%[parent_replaced])\n"
+		"   movl $0, %[faulted]\n"
+
+		".section .fixup, \"ax\"\n"
+		"3: movl $1, %[faulted]\n"
+		".previous\n"
+
+		_ASM_EXTABLE(1b, 3b)
+		_ASM_EXTABLE(2b, 3b)
+
+		: [parent_replaced] "=r" (parent), [old] "=r" (old),
+		  [faulted] "=r" (faulted)
+		: [parent_old] "0" (parent), [return_hooker] "r" (return_hooker)
+		: "memory"
+	);
+
+	if (unlikely(faulted)) {
+		ftrace_graph_stop();
+		WARN_ON(1);
+		return;
+	}
+
+	if (unlikely(!__kernel_text_address(old))) {
+		ftrace_graph_stop();
+		*parent = old;
+		WARN_ON(1);
+		return;
+	}
+
+	calltime = cpu_clock(raw_smp_processor_id());
+
+	if (push_return_trace(old, calltime,
+				self_addr, &trace.depth) == -EBUSY) {
+		*parent = old;
+		return;
+	}
+
+	trace.func = self_addr;
+
+	/* Only trace if the calling function expects to */
+	if (!ftrace_graph_entry(&trace)) {
+		current->curr_ret_stack--;
+		*parent = old;
+	}
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 1d3d0e71b04..1df869e5bd0 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -13,6 +13,7 @@
 #include <linux/seq_file.h>
 #include <linux/module.h>
 #include <linux/delay.h>
+#include <linux/ftrace.h>
 #include <asm/uaccess.h>
 #include <asm/io_apic.h>
 #include <asm/idle.h>
@@ -45,7 +46,7 @@ static inline void stack_overflow_check(struct pt_regs *regs)
  * SMP cross-CPU interrupts have their own specific
  * handlers).
  */
-asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
+asmlinkage unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
 	struct irq_desc *desc;
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index b8f3e9dbabd..e68bb9e3086 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -8,6 +8,7 @@
 #include <linux/module.h>
 #include <linux/pm.h>
 #include <linux/clockchips.h>
+#include <linux/ftrace.h>
 #include <asm/system.h>
 #include <asm/apic.h>
 
@@ -102,6 +103,9 @@ static inline int hlt_use_halt(void)
 void default_idle(void)
 {
 	if (hlt_use_halt()) {
+		struct power_trace it;
+
+		trace_power_start(&it, POWER_CSTATE, 1);
 		current_thread_info()->status &= ~TS_POLLING;
 		/*
 		 * TS_POLLING-cleared state must be visible before we
@@ -114,6 +118,7 @@ void default_idle(void)
 		else
 			local_irq_enable();
 		current_thread_info()->status |= TS_POLLING;
+		trace_power_end(&it);
 	} else {
 		local_irq_enable();
 		/* loop is done by the caller */
@@ -171,24 +176,31 @@ EXPORT_SYMBOL_GPL(cpu_idle_wait);
  */
 void mwait_idle_with_hints(unsigned long ax, unsigned long cx)
 {
+	struct power_trace it;
+
+	trace_power_start(&it, POWER_CSTATE, (ax>>4)+1);
 	if (!need_resched()) {
 		__monitor((void *)&current_thread_info()->flags, 0, 0);
 		smp_mb();
 		if (!need_resched())
 			__mwait(ax, cx);
 	}
+	trace_power_end(&it);
 }
 
 /* Default MONITOR/MWAIT with no hints, used for default C1 state */
 static void mwait_idle(void)
 {
+	struct power_trace it;
 	if (!need_resched()) {
+		trace_power_start(&it, POWER_CSTATE, 1);
 		__monitor((void *)&current_thread_info()->flags, 0, 0);
 		smp_mb();
 		if (!need_resched())
 			__sti_mwait(0, 0);
 		else
 			local_irq_enable();
+		trace_power_end(&it);
 	} else
 		local_irq_enable();
 }
@@ -200,9 +212,13 @@ static void mwait_idle(void)
  */
 static void poll_idle(void)
 {
+	struct power_trace it;
+
+	trace_power_start(&it, POWER_CSTATE, 0);
 	local_irq_enable();
 	while (!need_resched())
 		cpu_relax();
+	trace_power_end(&it);
 }
 
 /*
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 0a1302fe6d4..3ba155d2488 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -38,6 +38,7 @@
 #include <linux/percpu.h>
 #include <linux/prctl.h>
 #include <linux/dmi.h>
+#include <linux/ftrace.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -59,6 +60,7 @@
 #include <asm/idle.h>
 #include <asm/syscalls.h>
 #include <asm/smp.h>
+#include <asm/ds.h>
 
 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
@@ -250,14 +252,8 @@ void exit_thread(void)
 		tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
 		put_cpu();
 	}
-#ifdef CONFIG_X86_DS
-	/* Free any DS contexts that have not been properly released. */
-	if (unlikely(current->thread.ds_ctx)) {
-		/* we clear debugctl to make sure DS is not used. */
-		update_debugctlmsr(0);
-		ds_free(current->thread.ds_ctx);
-	}
-#endif /* CONFIG_X86_DS */
+
+	ds_exit_thread(current);
 }
 
 void flush_thread(void)
@@ -339,6 +335,12 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 		kfree(p->thread.io_bitmap_ptr);
 		p->thread.io_bitmap_max = 0;
 	}
+
+	ds_copy_thread(p, current);
+
+	clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR);
+	p->thread.debugctlmsr = 0;
+
 	return err;
 }
 
@@ -419,48 +421,19 @@ int set_tsc_mode(unsigned int val)
 	return 0;
 }
 
-#ifdef CONFIG_X86_DS
-static int update_debugctl(struct thread_struct *prev,
-			struct thread_struct *next, unsigned long debugctl)
-{
-	unsigned long ds_prev = 0;
-	unsigned long ds_next = 0;
-
-	if (prev->ds_ctx)
-		ds_prev = (unsigned long)prev->ds_ctx->ds;
-	if (next->ds_ctx)
-		ds_next = (unsigned long)next->ds_ctx->ds;
-
-	if (ds_next != ds_prev) {
-		/* we clear debugctl to make sure DS
-		 * is not in use when we change it */
-		debugctl = 0;
-		update_debugctlmsr(0);
-		wrmsr(MSR_IA32_DS_AREA, ds_next, 0);
-	}
-	return debugctl;
-}
-#else
-static int update_debugctl(struct thread_struct *prev,
-			struct thread_struct *next, unsigned long debugctl)
-{
-	return debugctl;
-}
-#endif /* CONFIG_X86_DS */
-
 static noinline void
 __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
 		 struct tss_struct *tss)
 {
 	struct thread_struct *prev, *next;
-	unsigned long debugctl;
 
 	prev = &prev_p->thread;
 	next = &next_p->thread;
 
-	debugctl = update_debugctl(prev, next, prev->debugctlmsr);
-
-	if (next->debugctlmsr != debugctl)
+	if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) ||
+	    test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR))
+		ds_switch_to(prev_p, next_p);
+	else if (next->debugctlmsr != prev->debugctlmsr)
 		update_debugctlmsr(next->debugctlmsr);
 
 	if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
@@ -482,15 +455,6 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
 			hard_enable_TSC();
 	}
 
-#ifdef CONFIG_X86_PTRACE_BTS
-	if (test_tsk_thread_flag(prev_p, TIF_BTS_TRACE_TS))
-		ptrace_bts_take_timestamp(prev_p, BTS_TASK_DEPARTS);
-
-	if (test_tsk_thread_flag(next_p, TIF_BTS_TRACE_TS))
-		ptrace_bts_take_timestamp(next_p, BTS_TASK_ARRIVES);
-#endif /* CONFIG_X86_PTRACE_BTS */
-
-
 	if (!test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
 		/*
 		 * Disable the bitmap via an invalid offset. We still cache
@@ -548,7 +512,8 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
  * the task-switch, and shows up in ret_from_fork in entry.S,
  * for example.
  */
-struct task_struct * __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
+__notrace_funcgraph struct task_struct *
+__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 {
 	struct thread_struct *prev = &prev_p->thread,
 				 *next = &next_p->thread;
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index c958120fb1b..416fb9282f4 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -39,6 +39,7 @@
 #include <linux/prctl.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
+#include <linux/ftrace.h>
 
 #include <asm/pgtable.h>
 #include <asm/system.h>
@@ -52,6 +53,7 @@
 #include <asm/ia32.h>
 #include <asm/idle.h>
 #include <asm/syscalls.h>
+#include <asm/ds.h>
 
 asmlinkage extern void ret_from_fork(void);
 
@@ -235,14 +237,8 @@ void exit_thread(void)
 		t->io_bitmap_max = 0;
 		put_cpu();
 	}
-#ifdef CONFIG_X86_DS
-	/* Free any DS contexts that have not been properly released. */
-	if (unlikely(t->ds_ctx)) {
-		/* we clear debugctl to make sure DS is not used. */
-		update_debugctlmsr(0);
-		ds_free(t->ds_ctx);
-	}
-#endif /* CONFIG_X86_DS */
+
+	ds_exit_thread(current);
 }
 
 void flush_thread(void)
@@ -372,6 +368,12 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 		if (err)
 			goto out;
 	}
+
+	ds_copy_thread(p, me);
+
+	clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR);
+	p->thread.debugctlmsr = 0;
+
 	err = 0;
 out:
 	if (err && p->thread.io_bitmap_ptr) {
@@ -470,35 +472,14 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
 				    struct tss_struct *tss)
 {
 	struct thread_struct *prev, *next;
-	unsigned long debugctl;
 
 	prev = &prev_p->thread,
 	next = &next_p->thread;
 
-	debugctl = prev->debugctlmsr;
-
-#ifdef CONFIG_X86_DS
-	{
-		unsigned long ds_prev = 0, ds_next = 0;
-
-		if (prev->ds_ctx)
-			ds_prev = (unsigned long)prev->ds_ctx->ds;
-		if (next->ds_ctx)
-			ds_next = (unsigned long)next->ds_ctx->ds;
-
-		if (ds_next != ds_prev) {
-			/*
-			 * We clear debugctl to make sure DS
-			 * is not in use when we change it:
-			 */
-			debugctl = 0;
-			update_debugctlmsr(0);
-			wrmsrl(MSR_IA32_DS_AREA, ds_next);
-		}
-	}
-#endif /* CONFIG_X86_DS */
-
-	if (next->debugctlmsr != debugctl)
+	if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) ||
+	    test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR))
+		ds_switch_to(prev_p, next_p);
+	else if (next->debugctlmsr != prev->debugctlmsr)
 		update_debugctlmsr(next->debugctlmsr);
 
 	if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
@@ -533,14 +514,6 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
 		 */
 		memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
 	}
-
-#ifdef CONFIG_X86_PTRACE_BTS
-	if (test_tsk_thread_flag(prev_p, TIF_BTS_TRACE_TS))
-		ptrace_bts_take_timestamp(prev_p, BTS_TASK_DEPARTS);
-
-	if (test_tsk_thread_flag(next_p, TIF_BTS_TRACE_TS))
-		ptrace_bts_take_timestamp(next_p, BTS_TASK_ARRIVES);
-#endif /* CONFIG_X86_PTRACE_BTS */
 }
 
 /*
@@ -551,8 +524,9 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
  * - could test fs/gs bitsliced
  *
  * Kprobes not supported here. Set the probe on schedule instead.
+ * Function graph tracer not supported too.
  */
-struct task_struct *
+__notrace_funcgraph struct task_struct *
 __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 {
 	struct thread_struct *prev = &prev_p->thread;
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 06180dff5b2..0a5df5f82fb 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -581,158 +581,91 @@ static int ioperm_get(struct task_struct *target,
 }
 
 #ifdef CONFIG_X86_PTRACE_BTS
-/*
- * The configuration for a particular BTS hardware implementation.
- */
-struct bts_configuration {
-	/* the size of a BTS record in bytes; at most BTS_MAX_RECORD_SIZE */
-	unsigned char  sizeof_bts;
-	/* the size of a field in the BTS record in bytes */
-	unsigned char  sizeof_field;
-	/* a bitmask to enable/disable BTS in DEBUGCTL MSR */
-	unsigned long debugctl_mask;
-};
-static struct bts_configuration bts_cfg;
-
-#define BTS_MAX_RECORD_SIZE (8 * 3)
-
-
-/*
- * Branch Trace Store (BTS) uses the following format. Different
- * architectures vary in the size of those fields.
- * - source linear address
- * - destination linear address
- * - flags
- *
- * Later architectures use 64bit pointers throughout, whereas earlier
- * architectures use 32bit pointers in 32bit mode.
- *
- * We compute the base address for the first 8 fields based on:
- * - the field size stored in the DS configuration
- * - the relative field position
- *
- * In order to store additional information in the BTS buffer, we use
- * a special source address to indicate that the record requires
- * special interpretation.
- *
- * Netburst indicated via a bit in the flags field whether the branch
- * was predicted; this is ignored.
- */
-
-enum bts_field {
-	bts_from = 0,
-	bts_to,
-	bts_flags,
-
-	bts_escape = (unsigned long)-1,
-	bts_qual = bts_to,
-	bts_jiffies = bts_flags
-};
-
-static inline unsigned long bts_get(const char *base, enum bts_field field)
-{
-	base += (bts_cfg.sizeof_field * field);
-	return *(unsigned long *)base;
-}
-
-static inline void bts_set(char *base, enum bts_field field, unsigned long val)
-{
-	base += (bts_cfg.sizeof_field * field);;
-	(*(unsigned long *)base) = val;
-}
-
-/*
- * Translate a BTS record from the raw format into the bts_struct format
- *
- * out (out): bts_struct interpretation
- * raw: raw BTS record
- */
-static void ptrace_bts_translate_record(struct bts_struct *out, const void *raw)
-{
-	memset(out, 0, sizeof(*out));
-	if (bts_get(raw, bts_from) == bts_escape) {
-		out->qualifier       = bts_get(raw, bts_qual);
-		out->variant.jiffies = bts_get(raw, bts_jiffies);
-	} else {
-		out->qualifier = BTS_BRANCH;
-		out->variant.lbr.from_ip = bts_get(raw, bts_from);
-		out->variant.lbr.to_ip   = bts_get(raw, bts_to);
-	}
-}
-
 static int ptrace_bts_read_record(struct task_struct *child, size_t index,
 				  struct bts_struct __user *out)
 {
-	struct bts_struct ret;
-	const void *bts_record;
-	size_t bts_index, bts_end;
+	const struct bts_trace *trace;
+	struct bts_struct bts;
+	const unsigned char *at;
 	int error;
 
-	error = ds_get_bts_end(child, &bts_end);
-	if (error < 0)
-		return error;
-
-	if (bts_end <= index)
-		return -EINVAL;
+	trace = ds_read_bts(child->bts);
+	if (!trace)
+		return -EPERM;
 
-	error = ds_get_bts_index(child, &bts_index);
-	if (error < 0)
-		return error;
+	at = trace->ds.top - ((index + 1) * trace->ds.size);
+	if ((void *)at < trace->ds.begin)
+		at += (trace->ds.n * trace->ds.size);
 
-	/* translate the ptrace bts index into the ds bts index */
-	bts_index += bts_end - (index + 1);
-	if (bts_end <= bts_index)
-		bts_index -= bts_end;
+	if (!trace->read)
+		return -EOPNOTSUPP;
 
-	error = ds_access_bts(child, bts_index, &bts_record);
+	error = trace->read(child->bts, at, &bts);
 	if (error < 0)
 		return error;
 
-	ptrace_bts_translate_record(&ret, bts_record);
-
-	if (copy_to_user(out, &ret, sizeof(ret)))
+	if (copy_to_user(out, &bts, sizeof(bts)))
 		return -EFAULT;
 
-	return sizeof(ret);
+	return sizeof(bts);
 }
 
 static int ptrace_bts_drain(struct task_struct *child,
 			    long size,
 			    struct bts_struct __user *out)
 {
-	struct bts_struct ret;
-	const unsigned char *raw;
-	size_t end, i;
-	int error;
+	const struct bts_trace *trace;
+	const unsigned char *at;
+	int error, drained = 0;
 
-	error = ds_get_bts_index(child, &end);
-	if (error < 0)
-		return error;
+	trace = ds_read_bts(child->bts);
+	if (!trace)
+		return -EPERM;
 
-	if (size < (end * sizeof(struct bts_struct)))
+	if (!trace->read)
+		return -EOPNOTSUPP;
+
+	if (size < (trace->ds.top - trace->ds.begin))
 		return -EIO;
 
-	error = ds_access_bts(child, 0, (const void **)&raw);
-	if (error < 0)
-		return error;
+	for (at = trace->ds.begin; (void *)at < trace->ds.top;
+	     out++, drained++, at += trace->ds.size) {
+		struct bts_struct bts;
+		int error;
 
-	for (i = 0; i < end; i++, out++, raw += bts_cfg.sizeof_bts) {
-		ptrace_bts_translate_record(&ret, raw);
+		error = trace->read(child->bts, at, &bts);
+		if (error < 0)
+			return error;
 
-		if (copy_to_user(out, &ret, sizeof(ret)))
+		if (copy_to_user(out, &bts, sizeof(bts)))
 			return -EFAULT;
 	}
 
-	error = ds_clear_bts(child);
+	memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
+
+	error = ds_reset_bts(child->bts);
 	if (error < 0)
 		return error;
 
-	return end;
+	return drained;
 }
 
-static void ptrace_bts_ovfl(struct task_struct *child)
+static int ptrace_bts_allocate_buffer(struct task_struct *child, size_t size)
 {
-	send_sig(child->thread.bts_ovfl_signal, child, 0);
+	child->bts_buffer = alloc_locked_buffer(size);
+	if (!child->bts_buffer)
+		return -ENOMEM;
+
+	child->bts_size = size;
+
+	return 0;
+}
+
+static void ptrace_bts_free_buffer(struct task_struct *child)
+{
+	free_locked_buffer(child->bts_buffer, child->bts_size);
+	child->bts_buffer = NULL;
+	child->bts_size = 0;
 }
 
 static int ptrace_bts_config(struct task_struct *child,
@@ -740,114 +673,86 @@ static int ptrace_bts_config(struct task_struct *child,
 			     const struct ptrace_bts_config __user *ucfg)
 {
 	struct ptrace_bts_config cfg;
-	int error = 0;
-
-	error = -EOPNOTSUPP;
-	if (!bts_cfg.sizeof_bts)
-		goto errout;
+	unsigned int flags = 0;
 
-	error = -EIO;
 	if (cfg_size < sizeof(cfg))
-		goto errout;
+		return -EIO;
 
-	error = -EFAULT;
 	if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
-		goto errout;
+		return -EFAULT;
 
-	error = -EINVAL;
-	if ((cfg.flags & PTRACE_BTS_O_SIGNAL) &&
-	    !(cfg.flags & PTRACE_BTS_O_ALLOC))
-		goto errout;
+	if (child->bts) {
+		ds_release_bts(child->bts);
+		child->bts = NULL;
+	}
 
-	if (cfg.flags & PTRACE_BTS_O_ALLOC) {
-		ds_ovfl_callback_t ovfl = NULL;
-		unsigned int sig = 0;
+	if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
+		if (!cfg.signal)
+			return -EINVAL;
 
-		/* we ignore the error in case we were not tracing child */
-		(void)ds_release_bts(child);
+		return -EOPNOTSUPP;
 
-		if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
-			if (!cfg.signal)
-				goto errout;
+		child->thread.bts_ovfl_signal = cfg.signal;
+	}
 
-			sig  = cfg.signal;
-			ovfl = ptrace_bts_ovfl;
-		}
+	if ((cfg.flags & PTRACE_BTS_O_ALLOC) &&
+	    (cfg.size != child->bts_size)) {
+		int error;
 
-		error = ds_request_bts(child, /* base = */ NULL, cfg.size, ovfl);
-		if (error < 0)
-			goto errout;
+		ptrace_bts_free_buffer(child);
 
-		child->thread.bts_ovfl_signal = sig;
+		error = ptrace_bts_allocate_buffer(child, cfg.size);
+		if (error < 0)
+			return error;
 	}
 
-	error = -EINVAL;
-	if (!child->thread.ds_ctx && cfg.flags)
-		goto errout;
-
 	if (cfg.flags & PTRACE_BTS_O_TRACE)
-		child->thread.debugctlmsr |= bts_cfg.debugctl_mask;
-	else
-		child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
+		flags |= BTS_USER;
 
 	if (cfg.flags & PTRACE_BTS_O_SCHED)
-		set_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
-	else
-		clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
+		flags |= BTS_TIMESTAMPS;
 
-	error = sizeof(cfg);
+	child->bts = ds_request_bts(child, child->bts_buffer, child->bts_size,
+				    /* ovfl = */ NULL, /* th = */ (size_t)-1,
+				    flags);
+	if (IS_ERR(child->bts)) {
+		int error = PTR_ERR(child->bts);
 
-out:
-	if (child->thread.debugctlmsr)
-		set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
-	else
-		clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
+		ptrace_bts_free_buffer(child);
+		child->bts = NULL;
 
-	return error;
+		return error;
+	}
 
-errout:
-	child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
-	clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
-	goto out;
+	return sizeof(cfg);
 }
 
 static int ptrace_bts_status(struct task_struct *child,
 			     long cfg_size,
 			     struct ptrace_bts_config __user *ucfg)
 {
+	const struct bts_trace *trace;
 	struct ptrace_bts_config cfg;
-	size_t end;
-	const void *base, *max;
-	int error;
 
 	if (cfg_size < sizeof(cfg))
 		return -EIO;
 
-	error = ds_get_bts_end(child, &end);
-	if (error < 0)
-		return error;
-
-	error = ds_access_bts(child, /* index = */ 0, &base);
-	if (error < 0)
-		return error;
-
-	error = ds_access_bts(child, /* index = */ end, &max);
-	if (error < 0)
-		return error;
+	trace = ds_read_bts(child->bts);
+	if (!trace)
+		return -EPERM;
 
 	memset(&cfg, 0, sizeof(cfg));
-	cfg.size = (max - base);
+	cfg.size = trace->ds.end - trace->ds.begin;
 	cfg.signal = child->thread.bts_ovfl_signal;
 	cfg.bts_size = sizeof(struct bts_struct);
 
 	if (cfg.signal)
 		cfg.flags |= PTRACE_BTS_O_SIGNAL;
 
-	if (test_tsk_thread_flag(child, TIF_DEBUGCTLMSR) &&
-	    child->thread.debugctlmsr & bts_cfg.debugctl_mask)
+	if (trace->ds.flags & BTS_USER)
 		cfg.flags |= PTRACE_BTS_O_TRACE;
 
-	if (test_tsk_thread_flag(child, TIF_BTS_TRACE_TS))
+	if (trace->ds.flags & BTS_TIMESTAMPS)
 		cfg.flags |= PTRACE_BTS_O_SCHED;
 
 	if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
@@ -856,109 +761,77 @@ static int ptrace_bts_status(struct task_struct *child,
 	return sizeof(cfg);
 }
 
-static int ptrace_bts_write_record(struct task_struct *child,
-				   const struct bts_struct *in)
+static int ptrace_bts_clear(struct task_struct *child)
 {
-	unsigned char bts_record[BTS_MAX_RECORD_SIZE];
+	const struct bts_trace *trace;
 
-	BUG_ON(BTS_MAX_RECORD_SIZE < bts_cfg.sizeof_bts);
+	trace = ds_read_bts(child->bts);
+	if (!trace)
+		return -EPERM;
 
-	memset(bts_record, 0, bts_cfg.sizeof_bts);
-	switch (in->qualifier) {
-	case BTS_INVALID:
-		break;
+	memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
 
-	case BTS_BRANCH:
-		bts_set(bts_record, bts_from, in->variant.lbr.from_ip);
-		bts_set(bts_record, bts_to,   in->variant.lbr.to_ip);
-		break;
+	return ds_reset_bts(child->bts);
+}
 
-	case BTS_TASK_ARRIVES:
-	case BTS_TASK_DEPARTS:
-		bts_set(bts_record, bts_from,    bts_escape);
-		bts_set(bts_record, bts_qual,    in->qualifier);
-		bts_set(bts_record, bts_jiffies, in->variant.jiffies);
-		break;
+static int ptrace_bts_size(struct task_struct *child)
+{
+	const struct bts_trace *trace;
 
-	default:
-		return -EINVAL;
-	}
+	trace = ds_read_bts(child->bts);
+	if (!trace)
+		return -EPERM;
 
-	/* The writing task will be the switched-to task on a context
-	 * switch. It needs to write into the switched-from task's BTS
-	 * buffer. */
-	return ds_unchecked_write_bts(child, bts_record, bts_cfg.sizeof_bts);
+	return (trace->ds.top - trace->ds.begin) / trace->ds.size;
 }
 
-void ptrace_bts_take_timestamp(struct task_struct *tsk,
-			       enum bts_qualifier qualifier)
+static void ptrace_bts_fork(struct task_struct *tsk)
 {
-	struct bts_struct rec = {
-		.qualifier = qualifier,
-		.variant.jiffies = jiffies_64
-	};
-
-	ptrace_bts_write_record(tsk, &rec);
+	tsk->bts = NULL;
+	tsk->bts_buffer = NULL;
+	tsk->bts_size = 0;
+	tsk->thread.bts_ovfl_signal = 0;
 }
 
-static const struct bts_configuration bts_cfg_netburst = {
-	.sizeof_bts    = sizeof(long) * 3,
-	.sizeof_field  = sizeof(long),
-	.debugctl_mask = (1<<2)|(1<<3)|(1<<5)
-};
+static void ptrace_bts_untrace(struct task_struct *child)
+{
+	if (unlikely(child->bts)) {
+		ds_release_bts(child->bts);
+		child->bts = NULL;
+
+		/* We cannot update total_vm and locked_vm since
+		   child's mm is already gone. But we can reclaim the
+		   memory. */
+		kfree(child->bts_buffer);
+		child->bts_buffer = NULL;
+		child->bts_size = 0;
+	}
+}
 
-static const struct bts_configuration bts_cfg_pentium_m = {
-	.sizeof_bts    = sizeof(long) * 3,
-	.sizeof_field  = sizeof(long),
-	.debugctl_mask = (1<<6)|(1<<7)
-};
+static void ptrace_bts_detach(struct task_struct *child)
+{
+	if (unlikely(child->bts)) {
+		ds_release_bts(child->bts);
+		child->bts = NULL;
 
-static const struct bts_configuration bts_cfg_core2 = {
-	.sizeof_bts    = 8 * 3,
-	.sizeof_field  = 8,
-	.debugctl_mask = (1<<6)|(1<<7)|(1<<9)
-};
+		ptrace_bts_free_buffer(child);
+	}
+}
+#else
+static inline void ptrace_bts_fork(struct task_struct *tsk) {}
+static inline void ptrace_bts_detach(struct task_struct *child) {}
+static inline void ptrace_bts_untrace(struct task_struct *child) {}
+#endif /* CONFIG_X86_PTRACE_BTS */
 
-static inline void bts_configure(const struct bts_configuration *cfg)
+void x86_ptrace_fork(struct task_struct *child, unsigned long clone_flags)
 {
-	bts_cfg = *cfg;
+	ptrace_bts_fork(child);
 }
 
-void __cpuinit ptrace_bts_init_intel(struct cpuinfo_x86 *c)
+void x86_ptrace_untrace(struct task_struct *child)
 {
-	switch (c->x86) {
-	case 0x6:
-		switch (c->x86_model) {
-		case 0 ... 0xC:
-			/* sorry, don't know about them */
-			break;
-		case 0xD:
-		case 0xE: /* Pentium M */
-			bts_configure(&bts_cfg_pentium_m);
-			break;
-		default: /* Core2, Atom, ... */
-			bts_configure(&bts_cfg_core2);
-			break;
-		}
-		break;
-	case 0xF:
-		switch (c->x86_model) {
-		case 0x0:
-		case 0x1:
-		case 0x2: /* Netburst */
-			bts_configure(&bts_cfg_netburst);
-			break;
-		default:
-			/* sorry, don't know about them */
-			break;
-		}
-		break;
-	default:
-		/* sorry, don't know about them */
-		break;
-	}
+	ptrace_bts_untrace(child);
 }
-#endif /* CONFIG_X86_PTRACE_BTS */
 
 /*
  * Called by kernel/ptrace.c when detaching..
@@ -971,15 +844,7 @@ void ptrace_disable(struct task_struct *child)
 #ifdef TIF_SYSCALL_EMU
 	clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 #endif
-#ifdef CONFIG_X86_PTRACE_BTS
-	(void)ds_release_bts(child);
-
-	child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
-	if (!child->thread.debugctlmsr)
-		clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
-
-	clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
-#endif /* CONFIG_X86_PTRACE_BTS */
+	ptrace_bts_detach(child);
 }
 
 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
@@ -1111,7 +976,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 		break;
 
 	case PTRACE_BTS_SIZE:
-		ret = ds_get_bts_index(child, /* pos = */ NULL);
+		ret = ptrace_bts_size(child);
 		break;
 
 	case PTRACE_BTS_GET:
@@ -1120,7 +985,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 		break;
 
 	case PTRACE_BTS_CLEAR:
-		ret = ds_clear_bts(child);
+		ret = ptrace_bts_clear(child);
 		break;
 
 	case PTRACE_BTS_DRAIN:
@@ -1383,6 +1248,14 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 
 	case PTRACE_GET_THREAD_AREA:
 	case PTRACE_SET_THREAD_AREA:
+#ifdef CONFIG_X86_PTRACE_BTS
+	case PTRACE_BTS_CONFIG:
+	case PTRACE_BTS_STATUS:
+	case PTRACE_BTS_SIZE:
+	case PTRACE_BTS_GET:
+	case PTRACE_BTS_CLEAR:
+	case PTRACE_BTS_DRAIN:
+#endif /* CONFIG_X86_PTRACE_BTS */
 		return arch_ptrace(child, request, addr, data);
 
 	default:
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 7a430c4d155..f8500c96944 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -288,7 +288,7 @@ static int __cpuinitdata unsafe_smp;
 /*
  * Activate a secondary processor.
  */
-static void __cpuinit start_secondary(void *unused)
+notrace static void __cpuinit start_secondary(void *unused)
 {
 	/*
 	 * Don't put *anything* before cpu_init(), SMP booting is too
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index a03e7f6d90c..10786af9554 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -6,6 +6,7 @@
 #include <linux/sched.h>
 #include <linux/stacktrace.h>
 #include <linux/module.h>
+#include <linux/uaccess.h>
 #include <asm/stacktrace.h>
 
 static void save_stack_warning(void *data, char *msg)
@@ -83,3 +84,66 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 		trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+
+/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
+
+struct stack_frame {
+	const void __user	*next_fp;
+	unsigned long		ret_addr;
+};
+
+static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
+{
+	int ret;
+
+	if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
+		return 0;
+
+	ret = 1;
+	pagefault_disable();
+	if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
+		ret = 0;
+	pagefault_enable();
+
+	return ret;
+}
+
+static inline void __save_stack_trace_user(struct stack_trace *trace)
+{
+	const struct pt_regs *regs = task_pt_regs(current);
+	const void __user *fp = (const void __user *)regs->bp;
+
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = regs->ip;
+
+	while (trace->nr_entries < trace->max_entries) {
+		struct stack_frame frame;
+
+		frame.next_fp = NULL;
+		frame.ret_addr = 0;
+		if (!copy_stack_frame(fp, &frame))
+			break;
+		if ((unsigned long)fp < regs->sp)
+			break;
+		if (frame.ret_addr) {
+			trace->entries[trace->nr_entries++] =
+				frame.ret_addr;
+		}
+		if (fp == frame.next_fp)
+			break;
+		fp = frame.next_fp;
+	}
+}
+
+void save_stack_trace_user(struct stack_trace *trace)
+{
+	/*
+	 * Trace user stack if we are not a kernel thread
+	 */
+	if (current->mm) {
+		__save_stack_trace_user(trace);
+	}
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+
diff --git a/arch/x86/kernel/vmlinux_32.lds.S b/arch/x86/kernel/vmlinux_32.lds.S
index a9b8560adbc..82c67559dde 100644
--- a/arch/x86/kernel/vmlinux_32.lds.S
+++ b/arch/x86/kernel/vmlinux_32.lds.S
@@ -44,6 +44,7 @@ SECTIONS
 	SCHED_TEXT
 	LOCK_TEXT
 	KPROBES_TEXT
+	IRQENTRY_TEXT
 	*(.fixup)
 	*(.gnu.warning)
   	_etext = .;			/* End of text section */
diff --git a/arch/x86/kernel/vmlinux_64.lds.S b/arch/x86/kernel/vmlinux_64.lds.S
index 46e05447405..1a614c0e6be 100644
--- a/arch/x86/kernel/vmlinux_64.lds.S
+++ b/arch/x86/kernel/vmlinux_64.lds.S
@@ -35,6 +35,7 @@ SECTIONS
 	SCHED_TEXT
 	LOCK_TEXT
 	KPROBES_TEXT
+	IRQENTRY_TEXT
 	*(.fixup)
 	*(.gnu.warning)
 	_etext = .;		/* End of text section */
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index ebf2f12900f..44153afc906 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -17,6 +17,9 @@
  *  want per guest time just set the kernel.vsyscall64 sysctl to 0.
  */
 
+/* Disable profiling for userspace code: */
+#define DISABLE_BRANCH_PROFILING
+
 #include <linux/time.h>
 #include <linux/init.h>
 #include <linux/kernel.h>