tracing/ftrace: implement a set_flag callback for tracers
[safe/jmp/linux-2.6] / kernel / trace / trace.c
index 4dcc4e8..9531fdd 100644 (file)
@@ -14,6 +14,7 @@
 #include <linux/utsrelease.h>
 #include <linux/kallsyms.h>
 #include <linux/seq_file.h>
+#include <linux/notifier.h>
 #include <linux/debugfs.h>
 #include <linux/pagemap.h>
 #include <linux/hardirq.h>
 #include <linux/ftrace.h>
 #include <linux/module.h>
 #include <linux/percpu.h>
+#include <linux/kdebug.h>
 #include <linux/ctype.h>
 #include <linux/init.h>
 #include <linux/poll.h>
 #include <linux/gfp.h>
 #include <linux/fs.h>
+#include <linux/kprobes.h>
 #include <linux/writeback.h>
 
 #include <linux/stacktrace.h>
+#include <linux/ring_buffer.h>
+#include <linux/irqflags.h>
 
 #include "trace.h"
 
+#define TRACE_BUFFER_FLAGS     (RB_FL_OVERWRITE)
+
 unsigned long __read_mostly    tracing_max_latency = (cycle_t)ULONG_MAX;
 unsigned long __read_mostly    tracing_thresh;
 
-static unsigned long __read_mostly     tracing_nr_buffers;
+/* For tracers that don't implement custom flags */
+static struct tracer_opt dummy_tracer_opt[] = {
+       { }
+};
+
+static struct tracer_flags dummy_tracer_flags = {
+       .val = 0,
+       .opts = dummy_tracer_opt
+};
+
+static int dummy_set_flag(u32 old_flags, u32 bit, int set)
+{
+       return 0;
+}
+
+/*
+ * Kill all tracing for good (never come back).
+ * It is initialized to 1 but will turn to zero if the initialization
+ * of the tracer is successful. But that is the only place that sets
+ * this back to zero.
+ */
+int tracing_disabled = 1;
+
+static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
+
+static inline void ftrace_disable_cpu(void)
+{
+       preempt_disable();
+       local_inc(&__get_cpu_var(ftrace_cpu_disabled));
+}
+
+static inline void ftrace_enable_cpu(void)
+{
+       local_dec(&__get_cpu_var(ftrace_cpu_disabled));
+       preempt_enable();
+}
+
 static cpumask_t __read_mostly         tracing_buffer_mask;
 
 #define for_each_tracing_cpu(cpu)      \
        for_each_cpu_mask(cpu, tracing_buffer_mask)
 
-/* dummy trace to disable tracing */
-static struct tracer no_tracer __read_mostly = {
-       .name           = "none",
-};
+/*
+ * ftrace_dump_on_oops - variable to dump ftrace buffer on oops
+ *
+ * If there is an oops (or kernel panic) and the ftrace_dump_on_oops
+ * is set, then ftrace_dump is called. This will output the contents
+ * of the ftrace buffers to the console.  This is very useful for
+ * capturing traces that lead to crashes and outputing it to a
+ * serial console.
+ *
+ * It is default off, but you can enable it with either specifying
+ * "ftrace_dump_on_oops" in the kernel command line, or setting
+ * /proc/sys/kernel/ftrace_dump_on_oops to true.
+ */
+int ftrace_dump_on_oops;
 
-static int trace_alloc_page(void);
-static int trace_free_page(void);
+static int tracing_set_tracer(char *buf);
 
-static int tracing_disabled = 1;
+static int __init set_ftrace(char *str)
+{
+       tracing_set_tracer(str);
+       return 1;
+}
+__setup("ftrace", set_ftrace);
 
-static unsigned long tracing_pages_allocated;
+static int __init set_ftrace_dump_on_oops(char *str)
+{
+       ftrace_dump_on_oops = 1;
+       return 1;
+}
+__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
 
 long
 ns2usecs(cycle_t nsec)
@@ -64,7 +126,9 @@ ns2usecs(cycle_t nsec)
 
 cycle_t ftrace_now(int cpu)
 {
-       return cpu_clock(cpu);
+       u64 ts = ring_buffer_time_stamp(cpu);
+       ring_buffer_normalize_time_stamp(cpu, &ts);
+       return ts;
 }
 
 /*
@@ -100,12 +164,35 @@ static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
 /* tracer_enabled is used to toggle activation of a tracer */
 static int                     tracer_enabled = 1;
 
+/**
+ * tracing_is_enabled - return tracer_enabled status
+ *
+ * This function is used by other tracers to know the status
+ * of the tracer_enabled flag.  Tracers may use this function
+ * to know if it should enable their features when starting
+ * up. See irqsoff tracer for an example (start_irqsoff_tracer).
+ */
+int tracing_is_enabled(void)
+{
+       return tracer_enabled;
+}
+
+/* function tracing enabled */
+int                            ftrace_function_enabled;
+
 /*
- * trace_nr_entries is the number of entries that is allocated
- * for a buffer. Note, the number of entries is always rounded
- * to ENTRIES_PER_PAGE.
+ * trace_buf_size is the size in bytes that is allocated
+ * for a buffer. Note, the number of bytes is always rounded
+ * to page size.
+ *
+ * This number is purposely set to a low number of 16384.
+ * If the dump on oops happens, it will be much appreciated
+ * to not have to wait for all that output. Anyway this can be
+ * boot time and run time configurable.
  */
-static unsigned long           trace_nr_entries = 65536UL;
+#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */
+
+static unsigned long           trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
 
 /* trace_types holds a link list of available tracers. */
 static struct tracer           *trace_types __read_mostly;
@@ -131,8 +218,9 @@ static DEFINE_MUTEX(trace_types_lock);
 /* trace_wait is a waitqueue for tasks blocked on trace_poll */
 static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
 
-/* trace_flags holds iter_ctrl options */
-unsigned long trace_flags = TRACE_ITER_PRINT_PARENT;
+/* trace_flags holds trace_options default values */
+unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
+       TRACE_ITER_ANNOTATE;
 
 /**
  * trace_wake_up - wake up tasks waiting for trace input
@@ -150,51 +238,27 @@ void trace_wake_up(void)
                wake_up(&trace_wait);
 }
 
-#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))
-
-static int __init set_nr_entries(char *str)
+static int __init set_buf_size(char *str)
 {
-       unsigned long nr_entries;
+       unsigned long buf_size;
        int ret;
 
        if (!str)
                return 0;
-       ret = strict_strtoul(str, 0, &nr_entries);
+       ret = strict_strtoul(str, 0, &buf_size);
        /* nr_entries can not be zero */
-       if (ret < 0 || nr_entries == 0)
+       if (ret < 0 || buf_size == 0)
                return 0;
-       trace_nr_entries = nr_entries;
+       trace_buf_size = buf_size;
        return 1;
 }
-__setup("trace_entries=", set_nr_entries);
+__setup("trace_buf_size=", set_buf_size);
 
 unsigned long nsecs_to_usecs(unsigned long nsecs)
 {
        return nsecs / 1000;
 }
 
-/*
- * trace_flag_type is an enumeration that holds different
- * states when a trace occurs. These are:
- *  IRQS_OFF   - interrupts were disabled
- *  NEED_RESCED - reschedule is requested
- *  HARDIRQ    - inside an interrupt handler
- *  SOFTIRQ    - inside a softirq handler
- */
-enum trace_flag_type {
-       TRACE_FLAG_IRQS_OFF             = 0x01,
-       TRACE_FLAG_NEED_RESCHED         = 0x02,
-       TRACE_FLAG_HARDIRQ              = 0x04,
-       TRACE_FLAG_SOFTIRQ              = 0x08,
-};
-
-/*
- * TRACE_ITER_SYM_MASK masks the options in trace_flags that
- * control the output of kernel symbols.
- */
-#define TRACE_ITER_SYM_MASK \
-       (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
-
 /* These must match the bit postions in trace_iterator_flags */
 static const char *trace_options[] = {
        "print-parent",
@@ -207,6 +271,10 @@ static const char *trace_options[] = {
        "block",
        "stacktrace",
        "sched-tree",
+       "ftrace_printk",
+       "ftrace_preempt",
+       "branch",
+       "annotate",
        NULL
 };
 
@@ -250,47 +318,6 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 }
 
 /**
- * check_pages - integrity check of trace buffers
- *
- * As a safty measure we check to make sure the data pages have not
- * been corrupted. TODO: configure to disable this because it adds
- * a bit of overhead.
- */
-void check_pages(struct trace_array_cpu *data)
-{
-       struct page *page, *tmp;
-
-       BUG_ON(data->trace_pages.next->prev != &data->trace_pages);
-       BUG_ON(data->trace_pages.prev->next != &data->trace_pages);
-
-       list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) {
-               BUG_ON(page->lru.next->prev != &page->lru);
-               BUG_ON(page->lru.prev->next != &page->lru);
-       }
-}
-
-/**
- * head_page - page address of the first page in per_cpu buffer.
- *
- * head_page returns the page address of the first page in
- * a per_cpu buffer. This also preforms various consistency
- * checks to make sure the buffer has not been corrupted.
- */
-void *head_page(struct trace_array_cpu *data)
-{
-       struct page *page;
-
-       check_pages(data);
-       if (list_empty(&data->trace_pages))
-               return NULL;
-
-       page = list_entry(data->trace_pages.next, struct page, lru);
-       BUG_ON(&page->lru == &data->trace_pages);
-
-       return page_address(page);
-}
-
-/**
  * trace_seq_printf - sequence printing of trace information
  * @s: trace sequence descriptor
  * @fmt: printf format string
@@ -371,28 +398,23 @@ trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
        return len;
 }
 
-#define HEX_CHARS 17
-static const char hex2asc[] = "0123456789abcdef";
+#define MAX_MEMHEX_BYTES       8
+#define HEX_CHARS              (MAX_MEMHEX_BYTES*2 + 1)
 
 static int
 trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
 {
        unsigned char hex[HEX_CHARS];
        unsigned char *data = mem;
-       unsigned char byte;
        int i, j;
 
-       BUG_ON(len >= HEX_CHARS);
-
 #ifdef __BIG_ENDIAN
        for (i = 0, j = 0; i < len; i++) {
 #else
        for (i = len-1, j = 0; i >= 0; i--) {
 #endif
-               byte = data[i];
-
-               hex[j++] = hex2asc[byte & 0x0f];
-               hex[j++] = hex2asc[byte >> 4];
+               hex[j++] = hex_asc_hi(data[i]);
+               hex[j++] = hex_asc_lo(data[i]);
        }
        hex[j++] = ' ';
 
@@ -436,34 +458,6 @@ trace_print_seq(struct seq_file *m, struct trace_seq *s)
        trace_seq_reset(s);
 }
 
-/*
- * flip the trace buffers between two trace descriptors.
- * This usually is the buffers between the global_trace and
- * the max_tr to record a snapshot of a current trace.
- *
- * The ftrace_max_lock must be held.
- */
-static void
-flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
-{
-       struct list_head flip_pages;
-
-       INIT_LIST_HEAD(&flip_pages);
-
-       memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx,
-               sizeof(struct trace_array_cpu) -
-               offsetof(struct trace_array_cpu, trace_head_idx));
-
-       check_pages(tr1);
-       check_pages(tr2);
-       list_splice_init(&tr1->trace_pages, &flip_pages);
-       list_splice_init(&tr2->trace_pages, &tr1->trace_pages);
-       list_splice_init(&flip_pages, &tr2->trace_pages);
-       BUG_ON(!list_empty(&flip_pages));
-       check_pages(tr1);
-       check_pages(tr2);
-}
-
 /**
  * update_max_tr - snapshot all trace buffers from global_trace to max_tr
  * @tr: tracer
@@ -476,17 +470,17 @@ flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
 void
 update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
-       struct trace_array_cpu *data;
-       int i;
+       struct ring_buffer *buf = tr->buffer;
 
        WARN_ON_ONCE(!irqs_disabled());
        __raw_spin_lock(&ftrace_max_lock);
-       /* clear out all the previous traces */
-       for_each_tracing_cpu(i) {
-               data = tr->data[i];
-               flip_trace(max_tr.data[i], data);
-               tracing_reset(data);
-       }
+
+       tr->buffer = max_tr.buffer;
+       max_tr.buffer = buf;
+
+       ftrace_disable_cpu();
+       ring_buffer_reset(tr->buffer);
+       ftrace_enable_cpu();
 
        __update_max_tr(tr, tsk, cpu);
        __raw_spin_unlock(&ftrace_max_lock);
@@ -503,16 +497,19 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 void
 update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
-       struct trace_array_cpu *data = tr->data[cpu];
-       int i;
+       int ret;
 
        WARN_ON_ONCE(!irqs_disabled());
        __raw_spin_lock(&ftrace_max_lock);
-       for_each_tracing_cpu(i)
-               tracing_reset(max_tr.data[i]);
 
-       flip_trace(max_tr.data[cpu], data);
-       tracing_reset(data);
+       ftrace_disable_cpu();
+
+       ring_buffer_reset(max_tr.buffer);
+       ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
+
+       ftrace_enable_cpu();
+
+       WARN_ON_ONCE(ret);
 
        __update_max_tr(tr, tsk, cpu);
        __raw_spin_unlock(&ftrace_max_lock);
@@ -546,12 +543,18 @@ int register_tracer(struct tracer *type)
                }
        }
 
+       if (!type->set_flag)
+               type->set_flag = &dummy_set_flag;
+       if (!type->flags)
+               type->flags = &dummy_tracer_flags;
+       else
+               if (!type->flags->opts)
+                       type->flags->opts = dummy_tracer_opt;
+
 #ifdef CONFIG_FTRACE_STARTUP_TEST
        if (type->selftest) {
                struct tracer *saved_tracer = current_trace;
-               struct trace_array_cpu *data;
                struct trace_array *tr = &global_trace;
-               int saved_ctrl = tr->ctrl;
                int i;
                /*
                 * Run a selftest on this tracer.
@@ -561,29 +564,21 @@ int register_tracer(struct tracer *type)
                 * If we fail, we do not register this tracer.
                 */
                for_each_tracing_cpu(i) {
-                       data = tr->data[i];
-                       if (!head_page(data))
-                               continue;
-                       tracing_reset(data);
+                       tracing_reset(tr, i);
                }
                current_trace = type;
-               tr->ctrl = 0;
                /* the test is responsible for initializing and enabling */
                pr_info("Testing tracer %s: ", type->name);
                ret = type->selftest(type, tr);
                /* the test is responsible for resetting too */
                current_trace = saved_tracer;
-               tr->ctrl = saved_ctrl;
                if (ret) {
                        printk(KERN_CONT "FAILED!\n");
                        goto out;
                }
                /* Only reset on passing, to avoid touching corrupted buffers */
                for_each_tracing_cpu(i) {
-                       data = tr->data[i];
-                       if (!head_page(data))
-                               continue;
-                       tracing_reset(data);
+                       tracing_reset(tr, i);
                }
                printk(KERN_CONT "PASSED\n");
        }
@@ -629,13 +624,11 @@ void unregister_tracer(struct tracer *type)
        mutex_unlock(&trace_types_lock);
 }
 
-void tracing_reset(struct trace_array_cpu *data)
+void tracing_reset(struct trace_array *tr, int cpu)
 {
-       data->trace_idx = 0;
-       data->overrun = 0;
-       data->trace_head = data->trace_tail = head_page(data);
-       data->trace_head_idx = 0;
-       data->trace_tail_idx = 0;
+       ftrace_disable_cpu();
+       ring_buffer_reset_cpu(tr->buffer, cpu);
+       ftrace_enable_cpu();
 }
 
 #define SAVED_CMDLINES 128
@@ -645,9 +638,6 @@ static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
 static int cmdline_idx;
 static DEFINE_SPINLOCK(trace_cmdline_lock);
 
-/* trace in all context switches */
-atomic_t trace_record_cmdline_enabled __read_mostly;
-
 /* temporary disable recording */
 atomic_t trace_record_cmdline_disabled __read_mostly;
 
@@ -658,6 +648,76 @@ static void trace_init_cmdlines(void)
        cmdline_idx = 0;
 }
 
+static int trace_stop_count;
+static DEFINE_SPINLOCK(tracing_start_lock);
+
+/**
+ * tracing_start - quick start of the tracer
+ *
+ * If tracing is enabled but was stopped by tracing_stop,
+ * this will start the tracer back up.
+ */
+void tracing_start(void)
+{
+       struct ring_buffer *buffer;
+       unsigned long flags;
+
+       if (tracing_disabled)
+               return;
+
+       spin_lock_irqsave(&tracing_start_lock, flags);
+       if (--trace_stop_count)
+               goto out;
+
+       if (trace_stop_count < 0) {
+               /* Someone screwed up their debugging */
+               WARN_ON_ONCE(1);
+               trace_stop_count = 0;
+               goto out;
+       }
+
+
+       buffer = global_trace.buffer;
+       if (buffer)
+               ring_buffer_record_enable(buffer);
+
+       buffer = max_tr.buffer;
+       if (buffer)
+               ring_buffer_record_enable(buffer);
+
+       ftrace_start();
+ out:
+       spin_unlock_irqrestore(&tracing_start_lock, flags);
+}
+
+/**
+ * tracing_stop - quick stop of the tracer
+ *
+ * Light weight way to stop tracing. Use in conjunction with
+ * tracing_start.
+ */
+void tracing_stop(void)
+{
+       struct ring_buffer *buffer;
+       unsigned long flags;
+
+       ftrace_stop();
+       spin_lock_irqsave(&tracing_start_lock, flags);
+       if (trace_stop_count++)
+               goto out;
+
+       buffer = global_trace.buffer;
+       if (buffer)
+               ring_buffer_record_disable(buffer);
+
+       buffer = max_tr.buffer;
+       if (buffer)
+               ring_buffer_record_disable(buffer);
+
+ out:
+       spin_unlock_irqrestore(&tracing_start_lock, flags);
+}
+
 void trace_stop_cmdline_recording(void);
 
 static void trace_save_cmdline(struct task_struct *tsk)
@@ -724,82 +784,20 @@ void tracing_record_cmdline(struct task_struct *tsk)
        trace_save_cmdline(tsk);
 }
 
-static inline struct list_head *
-trace_next_list(struct trace_array_cpu *data, struct list_head *next)
-{
-       /*
-        * Roundrobin - but skip the head (which is not a real page):
-        */
-       next = next->next;
-       if (unlikely(next == &data->trace_pages))
-               next = next->next;
-       BUG_ON(next == &data->trace_pages);
-
-       return next;
-}
-
-static inline void *
-trace_next_page(struct trace_array_cpu *data, void *addr)
-{
-       struct list_head *next;
-       struct page *page;
-
-       page = virt_to_page(addr);
-
-       next = trace_next_list(data, &page->lru);
-       page = list_entry(next, struct page, lru);
-
-       return page_address(page);
-}
-
-static inline struct trace_entry *
-tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data)
-{
-       unsigned long idx, idx_next;
-       struct trace_entry *entry;
-
-       data->trace_idx++;
-       idx = data->trace_head_idx;
-       idx_next = idx + 1;
-
-       BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE);
-
-       entry = data->trace_head + idx * TRACE_ENTRY_SIZE;
-
-       if (unlikely(idx_next >= ENTRIES_PER_PAGE)) {
-               data->trace_head = trace_next_page(data, data->trace_head);
-               idx_next = 0;
-       }
-
-       if (data->trace_head == data->trace_tail &&
-           idx_next == data->trace_tail_idx) {
-               /* overrun */
-               data->overrun++;
-               data->trace_tail_idx++;
-               if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
-                       data->trace_tail =
-                               trace_next_page(data, data->trace_tail);
-                       data->trace_tail_idx = 0;
-               }
-       }
-
-       data->trace_head_idx = idx_next;
-
-       return entry;
-}
-
-static inline void
-tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
+void
+tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
+                            int pc)
 {
        struct task_struct *tsk = current;
-       unsigned long pc;
-
-       pc = preempt_count();
 
-       entry->preempt_count    = pc & 0xff;
-       entry->pid              = (tsk) ? tsk->pid : 0;
-       entry->t                = ftrace_now(raw_smp_processor_id());
-       entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
+       entry->preempt_count            = pc & 0xff;
+       entry->pid                      = (tsk) ? tsk->pid : 0;
+       entry->flags =
+#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
+               (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
+#else
+               TRACE_FLAG_IRQS_NOSUPPORT |
+#endif
                ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
                ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
                (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
@@ -807,145 +805,170 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
 
 void
 trace_function(struct trace_array *tr, struct trace_array_cpu *data,
-              unsigned long ip, unsigned long parent_ip, unsigned long flags)
+              unsigned long ip, unsigned long parent_ip, unsigned long flags,
+              int pc)
 {
-       struct trace_entry *entry;
+       struct ring_buffer_event *event;
+       struct ftrace_entry *entry;
        unsigned long irq_flags;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, flags);
-       entry->type             = TRACE_FN;
-       entry->fn.ip            = ip;
-       entry->fn.parent_ip     = parent_ip;
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
-}
-
-void
-ftrace(struct trace_array *tr, struct trace_array_cpu *data,
-       unsigned long ip, unsigned long parent_ip, unsigned long flags)
-{
-       if (likely(!atomic_read(&data->disabled)))
-               trace_function(tr, data, ip, parent_ip, flags);
-}
+       /* If we are reading the ring buffer, don't trace */
+       if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+               return;
 
-#ifdef CONFIG_MMIOTRACE
-void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data,
-                                               struct mmiotrace_rw *rw)
-{
-       struct trace_entry *entry;
+       event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+                                        &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type                 = TRACE_FN;
+       entry->ip                       = ip;
+       entry->parent_ip                = parent_ip;
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+}
+
+#ifdef CONFIG_FUNCTION_RET_TRACER
+static void __trace_function_return(struct trace_array *tr,
+                               struct trace_array_cpu *data,
+                               struct ftrace_retfunc *trace,
+                               unsigned long flags,
+                               int pc)
+{
+       struct ring_buffer_event *event;
+       struct ftrace_ret_entry *entry;
        unsigned long irq_flags;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, 0);
-       entry->type             = TRACE_MMIO_RW;
-       entry->mmiorw           = *rw;
-
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
+       if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+               return;
 
-       trace_wake_up();
+       event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry),
+                                        &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type                 = TRACE_FN_RET;
+       entry->ip                       = trace->func;
+       entry->parent_ip        = trace->ret;
+       entry->rettime          = trace->rettime;
+       entry->calltime         = trace->calltime;
+       ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
 }
+#endif
 
-void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data,
-                                               struct mmiotrace_map *map)
+void
+ftrace(struct trace_array *tr, struct trace_array_cpu *data,
+       unsigned long ip, unsigned long parent_ip, unsigned long flags,
+       int pc)
 {
-       struct trace_entry *entry;
-       unsigned long irq_flags;
-
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, 0);
-       entry->type             = TRACE_MMIO_MAP;
-       entry->mmiomap          = *map;
-
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
-
-       trace_wake_up();
+       if (likely(!atomic_read(&data->disabled)))
+               trace_function(tr, data, ip, parent_ip, flags, pc);
 }
-#endif
 
-void __trace_stack(struct trace_array *tr,
-                  struct trace_array_cpu *data,
-                  unsigned long flags,
-                  int skip)
+static void ftrace_trace_stack(struct trace_array *tr,
+                              struct trace_array_cpu *data,
+                              unsigned long flags,
+                              int skip, int pc)
 {
-       struct trace_entry *entry;
+#ifdef CONFIG_STACKTRACE
+       struct ring_buffer_event *event;
+       struct stack_entry *entry;
        struct stack_trace trace;
+       unsigned long irq_flags;
 
        if (!(trace_flags & TRACE_ITER_STACKTRACE))
                return;
 
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, flags);
-       entry->type             = TRACE_STACK;
+       event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+                                        &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type         = TRACE_STACK;
 
-       memset(&entry->stack, 0, sizeof(entry->stack));
+       memset(&entry->caller, 0, sizeof(entry->caller));
 
        trace.nr_entries        = 0;
        trace.max_entries       = FTRACE_STACK_ENTRIES;
        trace.skip              = skip;
-       trace.entries           = entry->stack.caller;
+       trace.entries           = entry->caller;
 
        save_stack_trace(&trace);
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+#endif
 }
 
-void
-__trace_special(void *__tr, void *__data,
-               unsigned long arg1, unsigned long arg2, unsigned long arg3)
+void __trace_stack(struct trace_array *tr,
+                  struct trace_array_cpu *data,
+                  unsigned long flags,
+                  int skip)
+{
+       ftrace_trace_stack(tr, data, flags, skip, preempt_count());
+}
+
+static void
+ftrace_trace_special(void *__tr, void *__data,
+                    unsigned long arg1, unsigned long arg2, unsigned long arg3,
+                    int pc)
 {
+       struct ring_buffer_event *event;
        struct trace_array_cpu *data = __data;
        struct trace_array *tr = __tr;
-       struct trace_entry *entry;
+       struct special_entry *entry;
        unsigned long irq_flags;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, 0);
-       entry->type             = TRACE_SPECIAL;
-       entry->special.arg1     = arg1;
-       entry->special.arg2     = arg2;
-       entry->special.arg3     = arg3;
-       __trace_stack(tr, data, irq_flags, 4);
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
+       event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+                                        &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, 0, pc);
+       entry->ent.type                 = TRACE_SPECIAL;
+       entry->arg1                     = arg1;
+       entry->arg2                     = arg2;
+       entry->arg3                     = arg3;
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+       ftrace_trace_stack(tr, data, irq_flags, 4, pc);
 
        trace_wake_up();
 }
 
 void
+__trace_special(void *__tr, void *__data,
+               unsigned long arg1, unsigned long arg2, unsigned long arg3)
+{
+       ftrace_trace_special(__tr, __data, arg1, arg2, arg3, preempt_count());
+}
+
+void
 tracing_sched_switch_trace(struct trace_array *tr,
                           struct trace_array_cpu *data,
                           struct task_struct *prev,
                           struct task_struct *next,
-                          unsigned long flags)
+                          unsigned long flags, int pc)
 {
-       struct trace_entry *entry;
+       struct ring_buffer_event *event;
+       struct ctx_switch_entry *entry;
        unsigned long irq_flags;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, flags);
-       entry->type             = TRACE_CTX;
-       entry->ctx.prev_pid     = prev->pid;
-       entry->ctx.prev_prio    = prev->prio;
-       entry->ctx.prev_state   = prev->state;
-       entry->ctx.next_pid     = next->pid;
-       entry->ctx.next_prio    = next->prio;
-       entry->ctx.next_state   = next->state;
-       __trace_stack(tr, data, flags, 5);
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
+       event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+                                          &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type                 = TRACE_CTX;
+       entry->prev_pid                 = prev->pid;
+       entry->prev_prio                = prev->prio;
+       entry->prev_state               = prev->state;
+       entry->next_pid                 = next->pid;
+       entry->next_prio                = next->prio;
+       entry->next_state               = next->state;
+       entry->next_cpu = task_cpu(next);
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+       ftrace_trace_stack(tr, data, flags, 5, pc);
 }
 
 void
@@ -953,185 +976,263 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
                           struct trace_array_cpu *data,
                           struct task_struct *wakee,
                           struct task_struct *curr,
-                          unsigned long flags)
+                          unsigned long flags, int pc)
 {
-       struct trace_entry *entry;
+       struct ring_buffer_event *event;
+       struct ctx_switch_entry *entry;
        unsigned long irq_flags;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, flags);
-       entry->type             = TRACE_WAKE;
-       entry->ctx.prev_pid     = curr->pid;
-       entry->ctx.prev_prio    = curr->prio;
-       entry->ctx.prev_state   = curr->state;
-       entry->ctx.next_pid     = wakee->pid;
-       entry->ctx.next_prio    = wakee->prio;
-       entry->ctx.next_state   = wakee->state;
-       __trace_stack(tr, data, flags, 6);
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
+       event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+                                          &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type                 = TRACE_WAKE;
+       entry->prev_pid                 = curr->pid;
+       entry->prev_prio                = curr->prio;
+       entry->prev_state               = curr->state;
+       entry->next_pid                 = wakee->pid;
+       entry->next_prio                = wakee->prio;
+       entry->next_state               = wakee->state;
+       entry->next_cpu                 = task_cpu(wakee);
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+       ftrace_trace_stack(tr, data, flags, 6, pc);
 
        trace_wake_up();
 }
 
-#ifdef CONFIG_FTRACE
-static void
-function_trace_call(unsigned long ip, unsigned long parent_ip)
+void
+ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
 {
        struct trace_array *tr = &global_trace;
        struct trace_array_cpu *data;
        unsigned long flags;
-       long disabled;
        int cpu;
+       int pc;
 
-       if (unlikely(!tracer_enabled))
+       if (tracing_disabled)
                return;
 
+       pc = preempt_count();
        local_irq_save(flags);
        cpu = raw_smp_processor_id();
        data = tr->data[cpu];
-       disabled = atomic_inc_return(&data->disabled);
 
-       if (likely(disabled == 1))
-               trace_function(tr, data, ip, parent_ip, flags);
+       if (likely(atomic_inc_return(&data->disabled) == 1))
+               ftrace_trace_special(tr, data, arg1, arg2, arg3, pc);
 
        atomic_dec(&data->disabled);
        local_irq_restore(flags);
 }
 
-static struct ftrace_ops trace_ops __read_mostly =
-{
-       .func = function_trace_call,
-};
-
-void tracing_start_function_trace(void)
+#ifdef CONFIG_FUNCTION_TRACER
+static void
+function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
 {
-       register_ftrace_function(&trace_ops);
-}
+       struct trace_array *tr = &global_trace;
+       struct trace_array_cpu *data;
+       unsigned long flags;
+       long disabled;
+       int cpu, resched;
+       int pc;
 
-void tracing_stop_function_trace(void)
-{
-       unregister_ftrace_function(&trace_ops);
-}
-#endif
+       if (unlikely(!ftrace_function_enabled))
+               return;
 
-enum trace_file_type {
-       TRACE_FILE_LAT_FMT      = 1,
-};
+       pc = preempt_count();
+       resched = ftrace_preempt_disable();
+       local_save_flags(flags);
+       cpu = raw_smp_processor_id();
+       data = tr->data[cpu];
+       disabled = atomic_inc_return(&data->disabled);
 
-static struct trace_entry *
-trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data,
-               struct trace_iterator *iter, int cpu)
-{
-       struct page *page;
-       struct trace_entry *array;
+       if (likely(disabled == 1))
+               trace_function(tr, data, ip, parent_ip, flags, pc);
 
-       if (iter->next_idx[cpu] >= tr->entries ||
-           iter->next_idx[cpu] >= data->trace_idx ||
-           (data->trace_head == data->trace_tail &&
-            data->trace_head_idx == data->trace_tail_idx))
-               return NULL;
+       atomic_dec(&data->disabled);
+       ftrace_preempt_enable(resched);
+}
+
+static void
+function_trace_call(unsigned long ip, unsigned long parent_ip)
+{
+       struct trace_array *tr = &global_trace;
+       struct trace_array_cpu *data;
+       unsigned long flags;
+       long disabled;
+       int cpu;
+       int pc;
+
+       if (unlikely(!ftrace_function_enabled))
+               return;
+
+       /*
+        * Need to use raw, since this must be called before the
+        * recursive protection is performed.
+        */
+       local_irq_save(flags);
+       cpu = raw_smp_processor_id();
+       data = tr->data[cpu];
+       disabled = atomic_inc_return(&data->disabled);
+
+       if (likely(disabled == 1)) {
+               pc = preempt_count();
+               trace_function(tr, data, ip, parent_ip, flags, pc);
+       }
+
+       atomic_dec(&data->disabled);
+       local_irq_restore(flags);
+}
+
+#ifdef CONFIG_FUNCTION_RET_TRACER
+void trace_function_return(struct ftrace_retfunc *trace)
+{
+       struct trace_array *tr = &global_trace;
+       struct trace_array_cpu *data;
+       unsigned long flags;
+       long disabled;
+       int cpu;
+       int pc;
 
-       if (!iter->next_page[cpu]) {
-               /* Initialize the iterator for this cpu trace buffer */
-               WARN_ON(!data->trace_tail);
-               page = virt_to_page(data->trace_tail);
-               iter->next_page[cpu] = &page->lru;
-               iter->next_page_idx[cpu] = data->trace_tail_idx;
+       raw_local_irq_save(flags);
+       cpu = raw_smp_processor_id();
+       data = tr->data[cpu];
+       disabled = atomic_inc_return(&data->disabled);
+       if (likely(disabled == 1)) {
+               pc = preempt_count();
+               __trace_function_return(tr, data, trace, flags, pc);
        }
+       atomic_dec(&data->disabled);
+       raw_local_irq_restore(flags);
+}
+#endif /* CONFIG_FUNCTION_RET_TRACER */
+
+static struct ftrace_ops trace_ops __read_mostly =
+{
+       .func = function_trace_call,
+};
+
+void tracing_start_function_trace(void)
+{
+       ftrace_function_enabled = 0;
+
+       if (trace_flags & TRACE_ITER_PREEMPTONLY)
+               trace_ops.func = function_trace_call_preempt_only;
+       else
+               trace_ops.func = function_trace_call;
+
+       register_ftrace_function(&trace_ops);
+       ftrace_function_enabled = 1;
+}
+
+void tracing_stop_function_trace(void)
+{
+       ftrace_function_enabled = 0;
+       unregister_ftrace_function(&trace_ops);
+}
+#endif
+
+enum trace_file_type {
+       TRACE_FILE_LAT_FMT      = 1,
+       TRACE_FILE_ANNOTATE     = 2,
+};
+
+static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
+{
+       /* Don't allow ftrace to trace into the ring buffers */
+       ftrace_disable_cpu();
 
-       page = list_entry(iter->next_page[cpu], struct page, lru);
-       BUG_ON(&data->trace_pages == &page->lru);
+       iter->idx++;
+       if (iter->buffer_iter[iter->cpu])
+               ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
+
+       ftrace_enable_cpu();
+}
+
+static struct trace_entry *
+peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts)
+{
+       struct ring_buffer_event *event;
+       struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu];
+
+       /* Don't allow ftrace to trace into the ring buffers */
+       ftrace_disable_cpu();
+
+       if (buf_iter)
+               event = ring_buffer_iter_peek(buf_iter, ts);
+       else
+               event = ring_buffer_peek(iter->tr->buffer, cpu, ts);
 
-       array = page_address(page);
+       ftrace_enable_cpu();
 
-       WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE);
-       return &array[iter->next_page_idx[cpu]];
+       return event ? ring_buffer_event_data(event) : NULL;
 }
 
 static struct trace_entry *
-find_next_entry(struct trace_iterator *iter, int *ent_cpu)
+__find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
 {
-       struct trace_array *tr = iter->tr;
+       struct ring_buffer *buffer = iter->tr->buffer;
        struct trace_entry *ent, *next = NULL;
+       u64 next_ts = 0, ts;
        int next_cpu = -1;
        int cpu;
 
        for_each_tracing_cpu(cpu) {
-               if (!head_page(tr->data[cpu]))
+
+               if (ring_buffer_empty_cpu(buffer, cpu))
                        continue;
-               ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
+
+               ent = peek_next_entry(iter, cpu, &ts);
+
                /*
                 * Pick the entry with the smallest timestamp:
                 */
-               if (ent && (!next || ent->t < next->t)) {
+               if (ent && (!next || ts < next_ts)) {
                        next = ent;
                        next_cpu = cpu;
+                       next_ts = ts;
                }
        }
 
        if (ent_cpu)
                *ent_cpu = next_cpu;
 
+       if (ent_ts)
+               *ent_ts = next_ts;
+
        return next;
 }
 
-static void trace_iterator_increment(struct trace_iterator *iter)
+/* Find the next real entry, without updating the iterator itself */
+static struct trace_entry *
+find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
 {
-       iter->idx++;
-       iter->next_idx[iter->cpu]++;
-       iter->next_page_idx[iter->cpu]++;
-
-       if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) {
-               struct trace_array_cpu *data = iter->tr->data[iter->cpu];
-
-               iter->next_page_idx[iter->cpu] = 0;
-               iter->next_page[iter->cpu] =
-                       trace_next_list(data, iter->next_page[iter->cpu]);
-       }
+       return __find_next_entry(iter, ent_cpu, ent_ts);
 }
 
-static void trace_consume(struct trace_iterator *iter)
+/* Find the next real entry, and increment the iterator to the next entry */
+static void *find_next_entry_inc(struct trace_iterator *iter)
 {
-       struct trace_array_cpu *data = iter->tr->data[iter->cpu];
+       iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts);
 
-       data->trace_tail_idx++;
-       if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
-               data->trace_tail = trace_next_page(data, data->trace_tail);
-               data->trace_tail_idx = 0;
-       }
+       if (iter->ent)
+               trace_iterator_increment(iter, iter->cpu);
 
-       /* Check if we empty it, then reset the index */
-       if (data->trace_head == data->trace_tail &&
-           data->trace_head_idx == data->trace_tail_idx)
-               data->trace_idx = 0;
+       return iter->ent ? iter : NULL;
 }
 
-static void *find_next_entry_inc(struct trace_iterator *iter)
+static void trace_consume(struct trace_iterator *iter)
 {
-       struct trace_entry *next;
-       int next_cpu = -1;
-
-       next = find_next_entry(iter, &next_cpu);
-
-       iter->prev_ent = iter->ent;
-       iter->prev_cpu = iter->cpu;
-
-       iter->ent = next;
-       iter->cpu = next_cpu;
-
-       if (next)
-               trace_iterator_increment(iter);
-
-       return next ? iter : NULL;
+       /* Don't allow ftrace to trace into the ring buffers */
+       ftrace_disable_cpu();
+       ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts);
+       ftrace_enable_cpu();
 }
 
 static void *s_next(struct seq_file *m, void *v, loff_t *pos)
 {
        struct trace_iterator *iter = m->private;
-       void *last_ent = iter->ent;
        int i = (int)*pos;
        void *ent;
 
@@ -1151,9 +1252,6 @@ static void *s_next(struct seq_file *m, void *v, loff_t *pos)
 
        iter->pos = *pos;
 
-       if (last_ent && !ent)
-               seq_puts(m, "\n\nvim:ft=help\n");
-
        return ent;
 }
 
@@ -1162,7 +1260,7 @@ static void *s_start(struct seq_file *m, loff_t *pos)
        struct trace_iterator *iter = m->private;
        void *p = NULL;
        loff_t l = 0;
-       int i;
+       int cpu;
 
        mutex_lock(&trace_types_lock);
 
@@ -1173,22 +1271,19 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 
        atomic_inc(&trace_record_cmdline_disabled);
 
-       /* let the tracer grab locks here if needed */
-       if (current_trace->start)
-               current_trace->start(iter);
-
        if (*pos != iter->pos) {
                iter->ent = NULL;
                iter->cpu = 0;
                iter->idx = -1;
-               iter->prev_ent = NULL;
-               iter->prev_cpu = -1;
 
-               for_each_tracing_cpu(i) {
-                       iter->next_idx[i] = 0;
-                       iter->next_page[i] = NULL;
+               ftrace_disable_cpu();
+
+               for_each_tracing_cpu(cpu) {
+                       ring_buffer_iter_reset(iter->buffer_iter[cpu]);
                }
 
+               ftrace_enable_cpu();
+
                for (p = iter; p && l < *pos; p = s_next(m, p, &l))
                        ;
 
@@ -1202,26 +1297,39 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 
 static void s_stop(struct seq_file *m, void *p)
 {
-       struct trace_iterator *iter = m->private;
-
        atomic_dec(&trace_record_cmdline_disabled);
+       mutex_unlock(&trace_types_lock);
+}
 
-       /* let the tracer release locks here if needed */
-       if (current_trace && current_trace == iter->trace && iter->trace->stop)
-               iter->trace->stop(iter);
+#ifdef CONFIG_KRETPROBES
+static inline const char *kretprobed(const char *name)
+{
+       static const char tramp_name[] = "kretprobe_trampoline";
+       int size = sizeof(tramp_name);
 
-       mutex_unlock(&trace_types_lock);
+       if (strncmp(tramp_name, name, size) == 0)
+               return "[unknown/kretprobe'd]";
+       return name;
+}
+#else
+static inline const char *kretprobed(const char *name)
+{
+       return name;
 }
+#endif /* CONFIG_KRETPROBES */
 
 static int
 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 {
 #ifdef CONFIG_KALLSYMS
        char str[KSYM_SYMBOL_LEN];
+       const char *name;
 
        kallsyms_lookup(address, NULL, NULL, NULL, str);
 
-       return trace_seq_printf(s, fmt, str);
+       name = kretprobed(str);
+
+       return trace_seq_printf(s, fmt, name);
 #endif
        return 1;
 }
@@ -1232,9 +1340,12 @@ seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 {
 #ifdef CONFIG_KALLSYMS
        char str[KSYM_SYMBOL_LEN];
+       const char *name;
 
        sprint_symbol(str, address);
-       return trace_seq_printf(s, fmt, str);
+       name = kretprobed(str);
+
+       return trace_seq_printf(s, fmt, name);
 #endif
        return 1;
 }
@@ -1245,7 +1356,7 @@ seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 # define IP_FMT "%016lx"
 #endif
 
-static int
+int
 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 {
        int ret;
@@ -1268,21 +1379,21 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 
 static void print_lat_help_header(struct seq_file *m)
 {
-       seq_puts(m, "#                _------=> CPU#            \n");
-       seq_puts(m, "#               / _-----=> irqs-off        \n");
-       seq_puts(m, "#              | / _----=> need-resched    \n");
-       seq_puts(m, "#              || / _---=> hardirq/softirq \n");
-       seq_puts(m, "#              ||| / _--=> preempt-depth   \n");
-       seq_puts(m, "#              |||| /                      \n");
-       seq_puts(m, "#              |||||     delay             \n");
-       seq_puts(m, "#  cmd     pid ||||| time  |   caller      \n");
-       seq_puts(m, "#     \\   /    |||||   \\   |   /           \n");
+       seq_puts(m, "#                  _------=> CPU#            \n");
+       seq_puts(m, "#                 / _-----=> irqs-off        \n");
+       seq_puts(m, "#                | / _----=> need-resched    \n");
+       seq_puts(m, "#                || / _---=> hardirq/softirq \n");
+       seq_puts(m, "#                ||| / _--=> preempt-depth   \n");
+       seq_puts(m, "#                |||| /                      \n");
+       seq_puts(m, "#                |||||     delay             \n");
+       seq_puts(m, "#  cmd     pid   ||||| time  |   caller      \n");
+       seq_puts(m, "#     \\   /      |||||   \\   |   /           \n");
 }
 
 static void print_func_help_header(struct seq_file *m)
 {
-       seq_puts(m, "#           TASK-PID   CPU#    TIMESTAMP  FUNCTION\n");
-       seq_puts(m, "#              | |      |          |         |\n");
+       seq_puts(m, "#           TASK-PID    CPU#    TIMESTAMP  FUNCTION\n");
+       seq_puts(m, "#              | |       |          |         |\n");
 }
 
 
@@ -1293,23 +1404,16 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
        struct trace_array *tr = iter->tr;
        struct trace_array_cpu *data = tr->data[tr->cpu];
        struct tracer *type = current_trace;
-       unsigned long total   = 0;
-       unsigned long entries = 0;
-       int cpu;
+       unsigned long total;
+       unsigned long entries;
        const char *name = "preemption";
 
        if (type)
                name = type->name;
 
-       for_each_tracing_cpu(cpu) {
-               if (head_page(tr->data[cpu])) {
-                       total += tr->data[cpu]->trace_idx;
-                       if (tr->data[cpu]->trace_idx > tr->entries)
-                               entries += tr->entries;
-                       else
-                               entries += tr->data[cpu]->trace_idx;
-               }
-       }
+       entries = ring_buffer_entries(iter->tr->buffer);
+       total = entries +
+               ring_buffer_overruns(iter->tr->buffer);
 
        seq_printf(m, "%s latency trace v1.1.5 on %s\n",
                   name, UTS_RELEASE);
@@ -1325,7 +1429,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
                   "server",
 #elif defined(CONFIG_PREEMPT_VOLUNTARY)
                   "desktop",
-#elif defined(CONFIG_PREEMPT_DESKTOP)
+#elif defined(CONFIG_PREEMPT)
                   "preempt",
 #else
                   "unknown",
@@ -1366,9 +1470,10 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
        comm = trace_find_cmdline(entry->pid);
 
        trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
-       trace_seq_printf(s, "%d", cpu);
+       trace_seq_printf(s, "%3d", cpu);
        trace_seq_printf(s, "%c%c",
-                       (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
+                       (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
+                        (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : '.',
                        ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
 
        hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
@@ -1395,7 +1500,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 unsigned long preempt_mark_thresh = 100;
 
 static void
-lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
+lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
                    unsigned long rel_usecs)
 {
        trace_seq_printf(s, " %4lldus", abs_usecs);
@@ -1409,34 +1514,95 @@ lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
 
 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 
-static int
+/*
+ * The message is supposed to contain an ending newline.
+ * If the printing stops prematurely, try to add a newline of our own.
+ */
+void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter)
+{
+       struct trace_entry *ent;
+       struct trace_field_cont *cont;
+       bool ok = true;
+
+       ent = peek_next_entry(iter, iter->cpu, NULL);
+       if (!ent || ent->type != TRACE_CONT) {
+               trace_seq_putc(s, '\n');
+               return;
+       }
+
+       do {
+               cont = (struct trace_field_cont *)ent;
+               if (ok)
+                       ok = (trace_seq_printf(s, "%s", cont->buf) > 0);
+
+               ftrace_disable_cpu();
+
+               if (iter->buffer_iter[iter->cpu])
+                       ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
+               else
+                       ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
+
+               ftrace_enable_cpu();
+
+               ent = peek_next_entry(iter, iter->cpu, NULL);
+       } while (ent && ent->type == TRACE_CONT);
+
+       if (!ok)
+               trace_seq_putc(s, '\n');
+}
+
+static void test_cpu_buff_start(struct trace_iterator *iter)
+{
+       struct trace_seq *s = &iter->seq;
+
+       if (!(trace_flags & TRACE_ITER_ANNOTATE))
+               return;
+
+       if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
+               return;
+
+       if (cpu_isset(iter->cpu, iter->started))
+               return;
+
+       cpu_set(iter->cpu, iter->started);
+       trace_seq_printf(s, "##### CPU %u buffer started ####\n", iter->cpu);
+}
+
+static enum print_line_t
 print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 {
        struct trace_seq *s = &iter->seq;
        unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
-       struct trace_entry *next_entry = find_next_entry(iter, NULL);
+       struct trace_entry *next_entry;
        unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
        struct trace_entry *entry = iter->ent;
        unsigned long abs_usecs;
        unsigned long rel_usecs;
+       u64 next_ts;
        char *comm;
        int S, T;
        int i;
        unsigned state;
 
+       if (entry->type == TRACE_CONT)
+               return TRACE_TYPE_HANDLED;
+
+       test_cpu_buff_start(iter);
+
+       next_entry = find_next_entry(iter, NULL, &next_ts);
        if (!next_entry)
-               next_entry = entry;
-       rel_usecs = ns2usecs(next_entry->t - entry->t);
-       abs_usecs = ns2usecs(entry->t - iter->tr->time_start);
+               next_ts = iter->ts;
+       rel_usecs = ns2usecs(next_ts - iter->ts);
+       abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
 
        if (verbose) {
                comm = trace_find_cmdline(entry->pid);
-               trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]"
+               trace_seq_printf(s, "%16s %5d %3d %d %08x %08x [%08lx]"
                                 " %ld.%03ldms (+%ld.%03ldms): ",
                                 comm,
                                 entry->pid, cpu, entry->flags,
                                 entry->preempt_count, trace_idx,
-                                ns2usecs(entry->t),
+                                ns2usecs(iter->ts),
                                 abs_usecs/1000,
                                 abs_usecs % 1000, rel_usecs/1000,
                                 rel_usecs % 1000);
@@ -1445,49 +1611,94 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
                lat_print_timestamp(s, abs_usecs, rel_usecs);
        }
        switch (entry->type) {
-       case TRACE_FN:
-               seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+       case TRACE_FN: {
+               struct ftrace_entry *field;
+
+               trace_assign_type(field, entry);
+
+               seq_print_ip_sym(s, field->ip, sym_flags);
                trace_seq_puts(s, " (");
-               seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
+               seq_print_ip_sym(s, field->parent_ip, sym_flags);
                trace_seq_puts(s, ")\n");
                break;
+       }
        case TRACE_CTX:
-       case TRACE_WAKE:
-               T = entry->ctx.next_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.next_state] : 'X';
+       case TRACE_WAKE: {
+               struct ctx_switch_entry *field;
+
+               trace_assign_type(field, entry);
 
-               state = entry->ctx.prev_state ? __ffs(entry->ctx.prev_state) + 1 : 0;
+               T = field->next_state < sizeof(state_to_char) ?
+                       state_to_char[field->next_state] : 'X';
+
+               state = field->prev_state ?
+                       __ffs(field->prev_state) + 1 : 0;
                S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X';
-               comm = trace_find_cmdline(entry->ctx.next_pid);
-               trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n",
-                                entry->ctx.prev_pid,
-                                entry->ctx.prev_prio,
+               comm = trace_find_cmdline(field->next_pid);
+               trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
+                                field->prev_pid,
+                                field->prev_prio,
                                 S, entry->type == TRACE_CTX ? "==>" : "  +",
-                                entry->ctx.next_pid,
-                                entry->ctx.next_prio,
+                                field->next_cpu,
+                                field->next_pid,
+                                field->next_prio,
                                 T, comm);
                break;
-       case TRACE_SPECIAL:
+       }
+       case TRACE_SPECIAL: {
+               struct special_entry *field;
+
+               trace_assign_type(field, entry);
+
                trace_seq_printf(s, "# %ld %ld %ld\n",
-                                entry->special.arg1,
-                                entry->special.arg2,
-                                entry->special.arg3);
+                                field->arg1,
+                                field->arg2,
+                                field->arg3);
                break;
-       case TRACE_STACK:
+       }
+       case TRACE_STACK: {
+               struct stack_entry *field;
+
+               trace_assign_type(field, entry);
+
                for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
                        if (i)
                                trace_seq_puts(s, " <= ");
-                       seq_print_ip_sym(s, entry->stack.caller[i], sym_flags);
+                       seq_print_ip_sym(s, field->caller[i], sym_flags);
                }
                trace_seq_puts(s, "\n");
                break;
+       }
+       case TRACE_PRINT: {
+               struct print_entry *field;
+
+               trace_assign_type(field, entry);
+
+               seq_print_ip_sym(s, field->ip, sym_flags);
+               trace_seq_printf(s, ": %s", field->buf);
+               if (entry->flags & TRACE_FLAG_CONT)
+                       trace_seq_print_cont(s, iter);
+               break;
+       }
+       case TRACE_BRANCH: {
+               struct trace_branch *field;
+
+               trace_assign_type(field, entry);
+
+               trace_seq_printf(s, "[%s] %s:%s:%d\n",
+                                field->correct ? "  ok  " : " MISS ",
+                                field->func,
+                                field->file,
+                                field->line);
+               break;
+       }
        default:
                trace_seq_printf(s, "Unknown type %d\n", entry->type);
        }
-       return 1;
+       return TRACE_TYPE_HANDLED;
 }
 
-static int print_trace_fmt(struct trace_iterator *iter)
+static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 {
        struct trace_seq *s = &iter->seq;
        unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
@@ -1502,87 +1713,141 @@ static int print_trace_fmt(struct trace_iterator *iter)
 
        entry = iter->ent;
 
+       if (entry->type == TRACE_CONT)
+               return TRACE_TYPE_HANDLED;
+
+       test_cpu_buff_start(iter);
+
        comm = trace_find_cmdline(iter->ent->pid);
 
-       t = ns2usecs(entry->t);
+       t = ns2usecs(iter->ts);
        usec_rem = do_div(t, 1000000ULL);
        secs = (unsigned long)t;
 
        ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
        if (!ret)
-               return 0;
-       ret = trace_seq_printf(s, "[%02d] ", iter->cpu);
+               return TRACE_TYPE_PARTIAL_LINE;
+       ret = trace_seq_printf(s, "[%03d] ", iter->cpu);
        if (!ret)
-               return 0;
+               return TRACE_TYPE_PARTIAL_LINE;
        ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
        if (!ret)
-               return 0;
+               return TRACE_TYPE_PARTIAL_LINE;
 
        switch (entry->type) {
-       case TRACE_FN:
-               ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+       case TRACE_FN: {
+               struct ftrace_entry *field;
+
+               trace_assign_type(field, entry);
+
+               ret = seq_print_ip_sym(s, field->ip, sym_flags);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
-                                               entry->fn.parent_ip) {
+                                               field->parent_ip) {
                        ret = trace_seq_printf(s, " <-");
                        if (!ret)
-                               return 0;
-                       ret = seq_print_ip_sym(s, entry->fn.parent_ip,
+                               return TRACE_TYPE_PARTIAL_LINE;
+                       ret = seq_print_ip_sym(s,
+                                              field->parent_ip,
                                               sym_flags);
                        if (!ret)
-                               return 0;
+                               return TRACE_TYPE_PARTIAL_LINE;
                }
                ret = trace_seq_printf(s, "\n");
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
+       }
        case TRACE_CTX:
-       case TRACE_WAKE:
-               S = entry->ctx.prev_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.prev_state] : 'X';
-               T = entry->ctx.next_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.next_state] : 'X';
-               ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c\n",
-                                      entry->ctx.prev_pid,
-                                      entry->ctx.prev_prio,
+       case TRACE_WAKE: {
+               struct ctx_switch_entry *field;
+
+               trace_assign_type(field, entry);
+
+               S = field->prev_state < sizeof(state_to_char) ?
+                       state_to_char[field->prev_state] : 'X';
+               T = field->next_state < sizeof(state_to_char) ?
+                       state_to_char[field->next_state] : 'X';
+               ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
+                                      field->prev_pid,
+                                      field->prev_prio,
                                       S,
                                       entry->type == TRACE_CTX ? "==>" : "  +",
-                                      entry->ctx.next_pid,
-                                      entry->ctx.next_prio,
+                                      field->next_cpu,
+                                      field->next_pid,
+                                      field->next_prio,
                                       T);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
-       case TRACE_SPECIAL:
+       }
+       case TRACE_SPECIAL: {
+               struct special_entry *field;
+
+               trace_assign_type(field, entry);
+
                ret = trace_seq_printf(s, "# %ld %ld %ld\n",
-                                entry->special.arg1,
-                                entry->special.arg2,
-                                entry->special.arg3);
+                                field->arg1,
+                                field->arg2,
+                                field->arg3);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
-       case TRACE_STACK:
+       }
+       case TRACE_STACK: {
+               struct stack_entry *field;
+
+               trace_assign_type(field, entry);
+
                for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
                        if (i) {
                                ret = trace_seq_puts(s, " <= ");
                                if (!ret)
-                                       return 0;
+                                       return TRACE_TYPE_PARTIAL_LINE;
                        }
-                       ret = seq_print_ip_sym(s, entry->stack.caller[i],
+                       ret = seq_print_ip_sym(s, field->caller[i],
                                               sym_flags);
                        if (!ret)
-                               return 0;
+                               return TRACE_TYPE_PARTIAL_LINE;
                }
                ret = trace_seq_puts(s, "\n");
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
        }
-       return 1;
+       case TRACE_PRINT: {
+               struct print_entry *field;
+
+               trace_assign_type(field, entry);
+
+               seq_print_ip_sym(s, field->ip, sym_flags);
+               trace_seq_printf(s, ": %s", field->buf);
+               if (entry->flags & TRACE_FLAG_CONT)
+                       trace_seq_print_cont(s, iter);
+               break;
+       }
+       case TRACE_FN_RET: {
+               return print_return_function(iter);
+               break;
+       }
+       case TRACE_BRANCH: {
+               struct trace_branch *field;
+
+               trace_assign_type(field, entry);
+
+               trace_seq_printf(s, "[%s] %s:%s:%d\n",
+                                field->correct ? "  ok  " : " MISS ",
+                                field->func,
+                                field->file,
+                                field->line);
+               break;
+       }
+       }
+       return TRACE_TYPE_HANDLED;
 }
 
-static int print_raw_fmt(struct trace_iterator *iter)
+static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 {
        struct trace_seq *s = &iter->seq;
        struct trace_entry *entry;
@@ -1591,47 +1856,77 @@ static int print_raw_fmt(struct trace_iterator *iter)
 
        entry = iter->ent;
 
+       if (entry->type == TRACE_CONT)
+               return TRACE_TYPE_HANDLED;
+
        ret = trace_seq_printf(s, "%d %d %llu ",
-               entry->pid, iter->cpu, entry->t);
+               entry->pid, iter->cpu, iter->ts);
        if (!ret)
-               return 0;
+               return TRACE_TYPE_PARTIAL_LINE;
 
        switch (entry->type) {
-       case TRACE_FN:
+       case TRACE_FN: {
+               struct ftrace_entry *field;
+
+               trace_assign_type(field, entry);
+
                ret = trace_seq_printf(s, "%x %x\n",
-                                       entry->fn.ip, entry->fn.parent_ip);
+                                       field->ip,
+                                       field->parent_ip);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
+       }
        case TRACE_CTX:
-       case TRACE_WAKE:
-               S = entry->ctx.prev_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.prev_state] : 'X';
-               T = entry->ctx.next_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.next_state] : 'X';
+       case TRACE_WAKE: {
+               struct ctx_switch_entry *field;
+
+               trace_assign_type(field, entry);
+
+               S = field->prev_state < sizeof(state_to_char) ?
+                       state_to_char[field->prev_state] : 'X';
+               T = field->next_state < sizeof(state_to_char) ?
+                       state_to_char[field->next_state] : 'X';
                if (entry->type == TRACE_WAKE)
                        S = '+';
-               ret = trace_seq_printf(s, "%d %d %c %d %d %c\n",
-                                      entry->ctx.prev_pid,
-                                      entry->ctx.prev_prio,
+               ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
+                                      field->prev_pid,
+                                      field->prev_prio,
                                       S,
-                                      entry->ctx.next_pid,
-                                      entry->ctx.next_prio,
+                                      field->next_cpu,
+                                      field->next_pid,
+                                      field->next_prio,
                                       T);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
+       }
        case TRACE_SPECIAL:
-       case TRACE_STACK:
+       case TRACE_STACK: {
+               struct special_entry *field;
+
+               trace_assign_type(field, entry);
+
                ret = trace_seq_printf(s, "# %ld %ld %ld\n",
-                                entry->special.arg1,
-                                entry->special.arg2,
-                                entry->special.arg3);
+                                field->arg1,
+                                field->arg2,
+                                field->arg3);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
        }
-       return 1;
+       case TRACE_PRINT: {
+               struct print_entry *field;
+
+               trace_assign_type(field, entry);
+
+               trace_seq_printf(s, "# %lx %s", field->ip, field->buf);
+               if (entry->flags & TRACE_FLAG_CONT)
+                       trace_seq_print_cont(s, iter);
+               break;
+       }
+       }
+       return TRACE_TYPE_HANDLED;
 }
 
 #define SEQ_PUT_FIELD_RET(s, x)                                \
@@ -1642,11 +1937,12 @@ do {                                                    \
 
 #define SEQ_PUT_HEX_FIELD_RET(s, x)                    \
 do {                                                   \
+       BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES);     \
        if (!trace_seq_putmem_hex(s, &(x), sizeof(x)))  \
                return 0;                               \
 } while (0)
 
-static int print_hex_fmt(struct trace_iterator *iter)
+static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 {
        struct trace_seq *s = &iter->seq;
        unsigned char newline = '\n';
@@ -1655,97 +1951,139 @@ static int print_hex_fmt(struct trace_iterator *iter)
 
        entry = iter->ent;
 
+       if (entry->type == TRACE_CONT)
+               return TRACE_TYPE_HANDLED;
+
        SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
        SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
-       SEQ_PUT_HEX_FIELD_RET(s, entry->t);
+       SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
 
        switch (entry->type) {
-       case TRACE_FN:
-               SEQ_PUT_HEX_FIELD_RET(s, entry->fn.ip);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
+       case TRACE_FN: {
+               struct ftrace_entry *field;
+
+               trace_assign_type(field, entry);
+
+               SEQ_PUT_HEX_FIELD_RET(s, field->ip);
+               SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
                break;
+       }
        case TRACE_CTX:
-       case TRACE_WAKE:
-               S = entry->ctx.prev_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.prev_state] : 'X';
-               T = entry->ctx.next_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.next_state] : 'X';
+       case TRACE_WAKE: {
+               struct ctx_switch_entry *field;
+
+               trace_assign_type(field, entry);
+
+               S = field->prev_state < sizeof(state_to_char) ?
+                       state_to_char[field->prev_state] : 'X';
+               T = field->next_state < sizeof(state_to_char) ?
+                       state_to_char[field->next_state] : 'X';
                if (entry->type == TRACE_WAKE)
                        S = '+';
-               SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio);
+               SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
+               SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
                SEQ_PUT_HEX_FIELD_RET(s, S);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_pid);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_prio);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
+               SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
+               SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
+               SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
                SEQ_PUT_HEX_FIELD_RET(s, T);
                break;
+       }
        case TRACE_SPECIAL:
-       case TRACE_STACK:
-               SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3);
+       case TRACE_STACK: {
+               struct special_entry *field;
+
+               trace_assign_type(field, entry);
+
+               SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
+               SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
+               SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
                break;
        }
+       }
        SEQ_PUT_FIELD_RET(s, newline);
 
-       return 1;
+       return TRACE_TYPE_HANDLED;
 }
 
-static int print_bin_fmt(struct trace_iterator *iter)
+static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
 {
        struct trace_seq *s = &iter->seq;
        struct trace_entry *entry;
 
        entry = iter->ent;
 
+       if (entry->type == TRACE_CONT)
+               return TRACE_TYPE_HANDLED;
+
        SEQ_PUT_FIELD_RET(s, entry->pid);
        SEQ_PUT_FIELD_RET(s, entry->cpu);
-       SEQ_PUT_FIELD_RET(s, entry->t);
+       SEQ_PUT_FIELD_RET(s, iter->ts);
 
        switch (entry->type) {
-       case TRACE_FN:
-               SEQ_PUT_FIELD_RET(s, entry->fn.ip);
-               SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip);
+       case TRACE_FN: {
+               struct ftrace_entry *field;
+
+               trace_assign_type(field, entry);
+
+               SEQ_PUT_FIELD_RET(s, field->ip);
+               SEQ_PUT_FIELD_RET(s, field->parent_ip);
                break;
-       case TRACE_CTX:
-               SEQ_PUT_FIELD_RET(s, entry->ctx.prev_pid);
-               SEQ_PUT_FIELD_RET(s, entry->ctx.prev_prio);
-               SEQ_PUT_FIELD_RET(s, entry->ctx.prev_state);
-               SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid);
-               SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio);
-               SEQ_PUT_FIELD_RET(s, entry->ctx.next_state);
+       }
+       case TRACE_CTX: {
+               struct ctx_switch_entry *field;
+
+               trace_assign_type(field, entry);
+
+               SEQ_PUT_FIELD_RET(s, field->prev_pid);
+               SEQ_PUT_FIELD_RET(s, field->prev_prio);
+               SEQ_PUT_FIELD_RET(s, field->prev_state);
+               SEQ_PUT_FIELD_RET(s, field->next_pid);
+               SEQ_PUT_FIELD_RET(s, field->next_prio);
+               SEQ_PUT_FIELD_RET(s, field->next_state);
                break;
+       }
        case TRACE_SPECIAL:
-       case TRACE_STACK:
-               SEQ_PUT_FIELD_RET(s, entry->special.arg1);
-               SEQ_PUT_FIELD_RET(s, entry->special.arg2);
-               SEQ_PUT_FIELD_RET(s, entry->special.arg3);
+       case TRACE_STACK: {
+               struct special_entry *field;
+
+               trace_assign_type(field, entry);
+
+               SEQ_PUT_FIELD_RET(s, field->arg1);
+               SEQ_PUT_FIELD_RET(s, field->arg2);
+               SEQ_PUT_FIELD_RET(s, field->arg3);
                break;
        }
+       }
        return 1;
 }
 
 static int trace_empty(struct trace_iterator *iter)
 {
-       struct trace_array_cpu *data;
        int cpu;
 
        for_each_tracing_cpu(cpu) {
-               data = iter->tr->data[cpu];
-
-               if (head_page(data) && data->trace_idx &&
-                   (data->trace_tail != data->trace_head ||
-                    data->trace_tail_idx != data->trace_head_idx))
-                       return 0;
+               if (iter->buffer_iter[cpu]) {
+                       if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
+                               return 0;
+               } else {
+                       if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
+                               return 0;
+               }
        }
+
        return 1;
 }
 
-static int print_trace_line(struct trace_iterator *iter)
+static enum print_line_t print_trace_line(struct trace_iterator *iter)
 {
-       if (iter->trace && iter->trace->print_line)
-               return iter->trace->print_line(iter);
+       enum print_line_t ret;
+
+       if (iter->trace && iter->trace->print_line) {
+               ret = iter->trace->print_line(iter);
+               if (ret != TRACE_TYPE_UNHANDLED)
+                       return ret;
+       }
 
        if (trace_flags & TRACE_ITER_BIN)
                return print_bin_fmt(iter);
@@ -1801,6 +2139,8 @@ static struct trace_iterator *
 __tracing_open(struct inode *inode, struct file *file, int *ret)
 {
        struct trace_iterator *iter;
+       struct seq_file *m;
+       int cpu;
 
        if (tracing_disabled) {
                *ret = -ENODEV;
@@ -1821,26 +2161,47 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
        iter->trace = current_trace;
        iter->pos = -1;
 
+       /* Annotate start of buffers if we had overruns */
+       if (ring_buffer_overruns(iter->tr->buffer))
+               iter->iter_flags |= TRACE_FILE_ANNOTATE;
+
+
+       for_each_tracing_cpu(cpu) {
+
+               iter->buffer_iter[cpu] =
+                       ring_buffer_read_start(iter->tr->buffer, cpu);
+
+               if (!iter->buffer_iter[cpu])
+                       goto fail_buffer;
+       }
+
        /* TODO stop tracer */
        *ret = seq_open(file, &tracer_seq_ops);
-       if (!*ret) {
-               struct seq_file *m = file->private_data;
-               m->private = iter;
+       if (*ret)
+               goto fail_buffer;
 
-               /* stop the trace while dumping */
-               if (iter->tr->ctrl)
-                       tracer_enabled = 0;
+       m = file->private_data;
+       m->private = iter;
+
+       /* stop the trace while dumping */
+       tracing_stop();
 
-               if (iter->trace && iter->trace->open)
+       if (iter->trace && iter->trace->open)
                        iter->trace->open(iter);
-       } else {
-               kfree(iter);
-               iter = NULL;
-       }
+
        mutex_unlock(&trace_types_lock);
 
  out:
        return iter;
+
+ fail_buffer:
+       for_each_tracing_cpu(cpu) {
+               if (iter->buffer_iter[cpu])
+                       ring_buffer_read_finish(iter->buffer_iter[cpu]);
+       }
+       mutex_unlock(&trace_types_lock);
+
+       return ERR_PTR(-ENOMEM);
 }
 
 int tracing_open_generic(struct inode *inode, struct file *filp)
@@ -1856,14 +2217,19 @@ int tracing_release(struct inode *inode, struct file *file)
 {
        struct seq_file *m = (struct seq_file *)file->private_data;
        struct trace_iterator *iter = m->private;
+       int cpu;
 
        mutex_lock(&trace_types_lock);
+       for_each_tracing_cpu(cpu) {
+               if (iter->buffer_iter[cpu])
+                       ring_buffer_read_finish(iter->buffer_iter[cpu]);
+       }
+
        if (iter->trace && iter->trace->close)
                iter->trace->close(iter);
 
        /* reenable tracing if it was previously enabled */
-       if (iter->tr->ctrl)
-               tracer_enabled = 1;
+       tracing_start();
        mutex_unlock(&trace_types_lock);
 
        seq_release(inode, file);
@@ -2079,13 +2445,16 @@ static struct file_operations tracing_cpumask_fops = {
 };
 
 static ssize_t
-tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
+tracing_trace_options_read(struct file *filp, char __user *ubuf,
                       size_t cnt, loff_t *ppos)
 {
+       int i;
        char *buf;
        int r = 0;
        int len = 0;
-       int i;
+       u32 tracer_flags = current_trace->flags->val;
+       struct tracer_opt *trace_opts = current_trace->flags->opts;
+
 
        /* calulate max size */
        for (i = 0; trace_options[i]; i++) {
@@ -2093,6 +2462,15 @@ tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
                len += 3; /* "no" and space */
        }
 
+       /*
+        * Increase the size with names of options specific
+        * of the current tracer.
+        */
+       for (i = 0; trace_opts[i].name; i++) {
+               len += strlen(trace_opts[i].name);
+               len += 3; /* "no" and space */
+       }
+
        /* +2 for \n and \0 */
        buf = kmalloc(len + 2, GFP_KERNEL);
        if (!buf)
@@ -2105,6 +2483,15 @@ tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
                        r += sprintf(buf + r, "no%s ", trace_options[i]);
        }
 
+       for (i = 0; trace_opts[i].name; i++) {
+               if (tracer_flags & trace_opts[i].bit)
+                       r += sprintf(buf + r, "%s ",
+                               trace_opts[i].name);
+               else
+                       r += sprintf(buf + r, "no%s ",
+                               trace_opts[i].name);
+       }
+
        r += sprintf(buf + r, "\n");
        WARN_ON(r >= len + 2);
 
@@ -2115,13 +2502,48 @@ tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
        return r;
 }
 
+/* Try to assign a tracer specific option */
+static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
+{
+       struct tracer_flags *trace_flags = trace->flags;
+       struct tracer_opt *opts = NULL;
+       int ret = 0, i = 0;
+       int len;
+
+       for (i = 0; trace_flags->opts[i].name; i++) {
+               opts = &trace_flags->opts[i];
+               len = strlen(opts->name);
+
+               if (strncmp(cmp, opts->name, len) == 0) {
+                       ret = trace->set_flag(trace_flags->val,
+                               opts->bit, !neg);
+                       break;
+               }
+       }
+       /* Not found */
+       if (!trace_flags->opts[i].name)
+               return -EINVAL;
+
+       /* Refused to handle */
+       if (ret)
+               return ret;
+
+       if (neg)
+               trace_flags->val &= ~opts->bit;
+       else
+               trace_flags->val |= opts->bit;
+
+       return 0;
+}
+
 static ssize_t
-tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
+tracing_trace_options_write(struct file *filp, const char __user *ubuf,
                        size_t cnt, loff_t *ppos)
 {
        char buf[64];
        char *cmp = buf;
        int neg = 0;
+       int ret;
        int i;
 
        if (cnt >= sizeof(buf))
@@ -2148,11 +2570,13 @@ tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
                        break;
                }
        }
-       /*
-        * If no option could be set, return an error:
-        */
-       if (!trace_options[i])
-               return -EINVAL;
+
+       /* If no option could be set, test the specific tracer options */
+       if (!trace_options[i]) {
+               ret = set_tracer_option(current_trace, cmp, neg);
+               if (ret)
+                       return ret;
+       }
 
        filp->f_pos += cnt;
 
@@ -2161,8 +2585,8 @@ tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
 
 static struct file_operations tracing_iter_fops = {
        .open           = tracing_open_generic,
-       .read           = tracing_iter_ctrl_read,
-       .write          = tracing_iter_ctrl_write,
+       .read           = tracing_trace_options_read,
+       .write          = tracing_trace_options_write,
 };
 
 static const char readme_msg[] =
@@ -2176,9 +2600,9 @@ static const char readme_msg[] =
        "# echo sched_switch > /debug/tracing/current_tracer\n"
        "# cat /debug/tracing/current_tracer\n"
        "sched_switch\n"
-       "# cat /debug/tracing/iter_ctrl\n"
+       "# cat /debug/tracing/trace_options\n"
        "noprint-parent nosym-offset nosym-addr noverbose\n"
-       "# echo print-parent > /debug/tracing/iter_ctrl\n"
+       "# echo print-parent > /debug/tracing/trace_options\n"
        "# echo 1 > /debug/tracing/tracing_enabled\n"
        "# cat /debug/tracing/trace > /tmp/trace.txt\n"
        "echo 0 > /debug/tracing/tracing_enabled\n"
@@ -2201,11 +2625,10 @@ static ssize_t
 tracing_ctrl_read(struct file *filp, char __user *ubuf,
                  size_t cnt, loff_t *ppos)
 {
-       struct trace_array *tr = filp->private_data;
        char buf[64];
        int r;
 
-       r = sprintf(buf, "%ld\n", tr->ctrl);
+       r = sprintf(buf, "%u\n", tracer_enabled);
        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
@@ -2233,16 +2656,18 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf,
        val = !!val;
 
        mutex_lock(&trace_types_lock);
-       if (tr->ctrl ^ val) {
-               if (val)
+       if (tracer_enabled ^ val) {
+               if (val) {
                        tracer_enabled = 1;
-               else
+                       if (current_trace->start)
+                               current_trace->start(tr);
+                       tracing_start();
+               } else {
                        tracer_enabled = 0;
-
-               tr->ctrl = val;
-
-               if (current_trace && current_trace->ctrl_update)
-                       current_trace->ctrl_update(tr);
+                       tracing_stop();
+                       if (current_trace->stop)
+                               current_trace->stop(tr);
+               }
        }
        mutex_unlock(&trace_types_lock);
 
@@ -2268,14 +2693,52 @@ tracing_set_trace_read(struct file *filp, char __user *ubuf,
        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
+static int tracing_set_tracer(char *buf)
+{
+       struct trace_array *tr = &global_trace;
+       struct tracer *t;
+       int ret = 0;
+
+       mutex_lock(&trace_types_lock);
+       for (t = trace_types; t; t = t->next) {
+               if (strcmp(t->name, buf) == 0)
+                       break;
+       }
+       if (!t) {
+               ret = -EINVAL;
+               goto out;
+       }
+       if (t == current_trace)
+               goto out;
+
+       trace_branch_disable();
+       if (current_trace && current_trace->reset)
+               current_trace->reset(tr);
+
+       current_trace = t;
+       if (t->init) {
+               ret = t->init(tr);
+               if (ret)
+                       goto out;
+       }
+
+       trace_branch_enable(tr);
+ out:
+       mutex_unlock(&trace_types_lock);
+
+       return ret;
+}
+
 static ssize_t
 tracing_set_trace_write(struct file *filp, const char __user *ubuf,
                        size_t cnt, loff_t *ppos)
 {
-       struct trace_array *tr = &global_trace;
-       struct tracer *t;
        char buf[max_tracer_type_len+1];
        int i;
+       size_t ret;
+       int err;
+
+       ret = cnt;
 
        if (cnt > max_tracer_type_len)
                cnt = max_tracer_type_len;
@@ -2289,27 +2752,13 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
        for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
                buf[i] = 0;
 
-       mutex_lock(&trace_types_lock);
-       for (t = trace_types; t; t = t->next) {
-               if (strcmp(t->name, buf) == 0)
-                       break;
-       }
-       if (!t || t == current_trace)
-               goto out;
-
-       if (current_trace && current_trace->reset)
-               current_trace->reset(tr);
-
-       current_trace = t;
-       if (t->init)
-               t->init(tr);
-
- out:
-       mutex_unlock(&trace_types_lock);
+       err = tracing_set_tracer(buf);
+       if (err)
+               return err;
 
-       filp->f_pos += cnt;
+       filp->f_pos += ret;
 
-       return cnt;
+       return ret;
 }
 
 static ssize_t
@@ -2374,6 +2823,10 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
                return -ENOMEM;
 
        mutex_lock(&trace_types_lock);
+
+       /* trace pipe does not show start of buffer */
+       cpus_setall(iter->started);
+
        iter->tr = &global_trace;
        iter->trace = current_trace;
        filp->private_data = iter;
@@ -2424,20 +2877,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
                  size_t cnt, loff_t *ppos)
 {
        struct trace_iterator *iter = filp->private_data;
-       struct trace_array_cpu *data;
-       static cpumask_t mask;
-       unsigned long flags;
-#ifdef CONFIG_FTRACE
-       int ftrace_save;
-#endif
-       int cpu;
        ssize_t sret;
 
        /* return any leftover data */
        sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
        if (sret != -EBUSY)
                return sret;
-       sret = 0;
 
        trace_seq_reset(&iter->seq);
 
@@ -2448,6 +2893,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
                        goto out;
        }
 
+waitagain:
+       sret = 0;
        while (trace_empty(iter)) {
 
                if ((filp->f_flags & O_NONBLOCK)) {
@@ -2512,46 +2959,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
               offsetof(struct trace_iterator, seq));
        iter->pos = -1;
 
-       /*
-        * We need to stop all tracing on all CPUS to read the
-        * the next buffer. This is a bit expensive, but is
-        * not done often. We fill all what we can read,
-        * and then release the locks again.
-        */
-
-       cpus_clear(mask);
-       local_irq_save(flags);
-#ifdef CONFIG_FTRACE
-       ftrace_save = ftrace_enabled;
-       ftrace_enabled = 0;
-#endif
-       smp_wmb();
-       for_each_tracing_cpu(cpu) {
-               data = iter->tr->data[cpu];
-
-               if (!head_page(data) || !data->trace_idx)
-                       continue;
-
-               atomic_inc(&data->disabled);
-               cpu_set(cpu, mask);
-       }
-
-       for_each_cpu_mask(cpu, mask) {
-               data = iter->tr->data[cpu];
-               __raw_spin_lock(&data->lock);
-
-               if (data->overrun > iter->last_overrun[cpu])
-                       iter->overrun[cpu] +=
-                               data->overrun - iter->last_overrun[cpu];
-               iter->last_overrun[cpu] = data->overrun;
-       }
-
        while (find_next_entry_inc(iter) != NULL) {
-               int ret;
+               enum print_line_t ret;
                int len = iter->seq.len;
 
                ret = print_trace_line(iter);
-               if (!ret) {
+               if (ret == TRACE_TYPE_PARTIAL_LINE) {
                        /* don't print partial lines */
                        iter->seq.len = len;
                        break;
@@ -2563,26 +2976,17 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
                        break;
        }
 
-       for_each_cpu_mask(cpu, mask) {
-               data = iter->tr->data[cpu];
-               __raw_spin_unlock(&data->lock);
-       }
-
-       for_each_cpu_mask(cpu, mask) {
-               data = iter->tr->data[cpu];
-               atomic_dec(&data->disabled);
-       }
-#ifdef CONFIG_FTRACE
-       ftrace_enabled = ftrace_save;
-#endif
-       local_irq_restore(flags);
-
        /* Now copy what we have to the user */
        sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
        if (iter->seq.readpos >= iter->seq.len)
                trace_seq_reset(&iter->seq);
+
+       /*
+        * If there was nothing to send to user, inspite of consuming trace
+        * entries, go back to wait for more entries.
+        */
        if (sret == -EBUSY)
-               sret = 0;
+               goto waitagain;
 
 out:
        mutex_unlock(&trace_types_lock);
@@ -2598,7 +3002,7 @@ tracing_entries_read(struct file *filp, char __user *ubuf,
        char buf[64];
        int r;
 
-       r = sprintf(buf, "%lu\n", tr->entries);
+       r = sprintf(buf, "%lu\n", tr->entries >> 10);
        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
@@ -2608,7 +3012,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 {
        unsigned long val;
        char buf[64];
-       int ret;
+       int ret, cpu;
 
        if (cnt >= sizeof(buf))
                return -EINVAL;
@@ -2628,64 +3032,109 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 
        mutex_lock(&trace_types_lock);
 
-       if (current_trace != &no_tracer) {
-               cnt = -EBUSY;
-               pr_info("ftrace: set current_tracer to none"
-                       " before modifying buffer size\n");
-               goto out;
-       }
-
-       if (val > global_trace.entries) {
-               long pages_requested;
-               unsigned long freeable_pages;
-
-               /* make sure we have enough memory before mapping */
-               pages_requested =
-                       (val + (ENTRIES_PER_PAGE-1)) / ENTRIES_PER_PAGE;
+       tracing_stop();
 
-               /* account for each buffer (and max_tr) */
-               pages_requested *= tracing_nr_buffers * 2;
-
-               /* Check for overflow */
-               if (pages_requested < 0) {
-                       cnt = -ENOMEM;
-                       goto out;
-               }
+       /* disable all cpu buffers */
+       for_each_tracing_cpu(cpu) {
+               if (global_trace.data[cpu])
+                       atomic_inc(&global_trace.data[cpu]->disabled);
+               if (max_tr.data[cpu])
+                       atomic_inc(&max_tr.data[cpu]->disabled);
+       }
 
-               freeable_pages = determine_dirtyable_memory();
+       /* value is in KB */
+       val <<= 10;
 
-               /* we only allow to request 1/4 of useable memory */
-               if (pages_requested >
-                   ((freeable_pages + tracing_pages_allocated) / 4)) {
-                       cnt = -ENOMEM;
+       if (val != global_trace.entries) {
+               ret = ring_buffer_resize(global_trace.buffer, val);
+               if (ret < 0) {
+                       cnt = ret;
                        goto out;
                }
 
-               while (global_trace.entries < val) {
-                       if (trace_alloc_page()) {
-                               cnt = -ENOMEM;
-                               goto out;
+               ret = ring_buffer_resize(max_tr.buffer, val);
+               if (ret < 0) {
+                       int r;
+                       cnt = ret;
+                       r = ring_buffer_resize(global_trace.buffer,
+                                              global_trace.entries);
+                       if (r < 0) {
+                               /* AARGH! We are left with different
+                                * size max buffer!!!! */
+                               WARN_ON(1);
+                               tracing_disabled = 1;
                        }
-                       /* double check that we don't go over the known pages */
-                       if (tracing_pages_allocated > pages_requested)
-                               break;
+                       goto out;
                }
 
-       } else {
-               /* include the number of entries in val (inc of page entries) */
-               while (global_trace.entries > val + (ENTRIES_PER_PAGE - 1))
-                       trace_free_page();
+               global_trace.entries = val;
        }
 
        filp->f_pos += cnt;
 
+       /* If check pages failed, return ENOMEM */
+       if (tracing_disabled)
+               cnt = -ENOMEM;
  out:
+       for_each_tracing_cpu(cpu) {
+               if (global_trace.data[cpu])
+                       atomic_dec(&global_trace.data[cpu]->disabled);
+               if (max_tr.data[cpu])
+                       atomic_dec(&max_tr.data[cpu]->disabled);
+       }
+
+       tracing_start();
        max_tr.entries = global_trace.entries;
        mutex_unlock(&trace_types_lock);
 
        return cnt;
 }
 
+static int mark_printk(const char *fmt, ...)
+{
+       int ret;
+       va_list args;
+       va_start(args, fmt);
+       ret = trace_vprintk(0, fmt, args);
+       va_end(args);
+       return ret;
+}
+
+static ssize_t
+tracing_mark_write(struct file *filp, const char __user *ubuf,
+                                       size_t cnt, loff_t *fpos)
+{
+       char *buf;
+       char *end;
+
+       if (tracing_disabled)
+               return -EINVAL;
+
+       if (cnt > TRACE_BUF_SIZE)
+               cnt = TRACE_BUF_SIZE;
+
+       buf = kmalloc(cnt + 1, GFP_KERNEL);
+       if (buf == NULL)
+               return -ENOMEM;
+
+       if (copy_from_user(buf, ubuf, cnt)) {
+               kfree(buf);
+               return -EFAULT;
+       }
+
+       /* Cut from the first nil or newline. */
+       buf[cnt] = '\0';
+       end = strchr(buf, '\n');
+       if (end)
+               *end = '\0';
+
+       cnt = mark_printk("%s\n", buf);
+       kfree(buf);
+       *fpos += cnt;
+
+       return cnt;
+}
+
 static struct file_operations tracing_max_lat_fops = {
        .open           = tracing_open_generic,
        .read           = tracing_max_lat_read,
@@ -2717,24 +3166,45 @@ static struct file_operations tracing_entries_fops = {
        .write          = tracing_entries_write,
 };
 
+static struct file_operations tracing_mark_fops = {
+       .open           = tracing_open_generic,
+       .write          = tracing_mark_write,
+};
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 
+int __weak ftrace_arch_read_dyn_info(char *buf, int size)
+{
+       return 0;
+}
+
 static ssize_t
-tracing_read_long(struct file *filp, char __user *ubuf,
+tracing_read_dyn_info(struct file *filp, char __user *ubuf,
                  size_t cnt, loff_t *ppos)
 {
+       static char ftrace_dyn_info_buffer[1024];
+       static DEFINE_MUTEX(dyn_info_mutex);
        unsigned long *p = filp->private_data;
-       char buf[64];
+       char *buf = ftrace_dyn_info_buffer;
+       int size = ARRAY_SIZE(ftrace_dyn_info_buffer);
        int r;
 
-       r = sprintf(buf, "%ld\n", *p);
+       mutex_lock(&dyn_info_mutex);
+       r = sprintf(buf, "%ld ", *p);
 
-       return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+       r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r);
+       buf[r++] = '\n';
+
+       r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+
+       mutex_unlock(&dyn_info_mutex);
+
+       return r;
 }
 
-static struct file_operations tracing_read_long_fops = {
+static struct file_operations tracing_dyn_info_fops = {
        .open           = tracing_open_generic,
-       .read           = tracing_read_long,
+       .read           = tracing_read_dyn_info,
 };
 #endif
 
@@ -2763,7 +3233,7 @@ struct dentry *tracing_init_dentry(void)
 #include "trace_selftest.c"
 #endif
 
-static __init void tracer_init_debugfs(void)
+static __init int tracer_init_debugfs(void)
 {
        struct dentry *d_tracer;
        struct dentry *entry;
@@ -2775,10 +3245,10 @@ static __init void tracer_init_debugfs(void)
        if (!entry)
                pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
 
-       entry = debugfs_create_file("iter_ctrl", 0644, d_tracer,
+       entry = debugfs_create_file("trace_options", 0644, d_tracer,
                                    NULL, &tracing_iter_fops);
        if (!entry)
-               pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
+               pr_warning("Could not create debugfs 'trace_options' entry\n");
 
        entry = debugfs_create_file("tracing_cpumask", 0644, d_tracer,
                                    NULL, &tracing_cpumask_fops);
@@ -2798,12 +3268,12 @@ static __init void tracer_init_debugfs(void)
        entry = debugfs_create_file("available_tracers", 0444, d_tracer,
                                    &global_trace, &show_traces_fops);
        if (!entry)
-               pr_warning("Could not create debugfs 'trace' entry\n");
+               pr_warning("Could not create debugfs 'available_tracers' entry\n");
 
        entry = debugfs_create_file("current_tracer", 0444, d_tracer,
                                    &global_trace, &set_tracer_fops);
        if (!entry)
-               pr_warning("Could not create debugfs 'trace' entry\n");
+               pr_warning("Could not create debugfs 'current_tracer' entry\n");
 
        entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer,
                                    &tracing_max_latency,
@@ -2816,7 +3286,7 @@ static __init void tracer_init_debugfs(void)
                                    &tracing_thresh, &tracing_max_lat_fops);
        if (!entry)
                pr_warning("Could not create debugfs "
-                          "'tracing_threash' entry\n");
+                          "'tracing_thresh' entry\n");
        entry = debugfs_create_file("README", 0644, d_tracer,
                                    NULL, &tracing_readme_fops);
        if (!entry)
@@ -2826,248 +3296,288 @@ static __init void tracer_init_debugfs(void)
                                    NULL, &tracing_pipe_fops);
        if (!entry)
                pr_warning("Could not create debugfs "
-                          "'tracing_threash' entry\n");
+                          "'trace_pipe' entry\n");
 
-       entry = debugfs_create_file("trace_entries", 0644, d_tracer,
+       entry = debugfs_create_file("buffer_size_kb", 0644, d_tracer,
                                    &global_trace, &tracing_entries_fops);
        if (!entry)
                pr_warning("Could not create debugfs "
-                          "'tracing_threash' entry\n");
+                          "'buffer_size_kb' entry\n");
+
+       entry = debugfs_create_file("trace_marker", 0220, d_tracer,
+                                   NULL, &tracing_mark_fops);
+       if (!entry)
+               pr_warning("Could not create debugfs "
+                          "'trace_marker' entry\n");
 
 #ifdef CONFIG_DYNAMIC_FTRACE
        entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
                                    &ftrace_update_tot_cnt,
-                                   &tracing_read_long_fops);
+                                   &tracing_dyn_info_fops);
        if (!entry)
                pr_warning("Could not create debugfs "
                           "'dyn_ftrace_total_info' entry\n");
 #endif
+#ifdef CONFIG_SYSPROF_TRACER
+       init_tracer_sysprof_debugfs(d_tracer);
+#endif
+       return 0;
 }
 
-static int trace_alloc_page(void)
+int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 {
+       static DEFINE_SPINLOCK(trace_buf_lock);
+       static char trace_buf[TRACE_BUF_SIZE];
+
+       struct ring_buffer_event *event;
+       struct trace_array *tr = &global_trace;
        struct trace_array_cpu *data;
-       struct page *page, *tmp;
-       LIST_HEAD(pages);
-       void *array;
-       unsigned pages_allocated = 0;
-       int i;
+       struct print_entry *entry;
+       unsigned long flags, irq_flags;
+       int cpu, len = 0, size, pc;
 
-       /* first allocate a page for each CPU */
-       for_each_tracing_cpu(i) {
-               array = (void *)__get_free_page(GFP_KERNEL);
-               if (array == NULL) {
-                       printk(KERN_ERR "tracer: failed to allocate page"
-                              "for trace buffer!\n");
-                       goto free_pages;
-               }
+       if (tracing_disabled)
+               return 0;
 
-               pages_allocated++;
-               page = virt_to_page(array);
-               list_add(&page->lru, &pages);
+       pc = preempt_count();
+       preempt_disable_notrace();
+       cpu = raw_smp_processor_id();
+       data = tr->data[cpu];
 
-/* Only allocate if we are actually using the max trace */
-#ifdef CONFIG_TRACER_MAX_TRACE
-               array = (void *)__get_free_page(GFP_KERNEL);
-               if (array == NULL) {
-                       printk(KERN_ERR "tracer: failed to allocate page"
-                              "for trace buffer!\n");
-                       goto free_pages;
-               }
-               pages_allocated++;
-               page = virt_to_page(array);
-               list_add(&page->lru, &pages);
-#endif
-       }
+       if (unlikely(atomic_read(&data->disabled)))
+               goto out;
 
-       /* Now that we successfully allocate a page per CPU, add them */
-       for_each_tracing_cpu(i) {
-               data = global_trace.data[i];
-               page = list_entry(pages.next, struct page, lru);
-               list_del_init(&page->lru);
-               list_add_tail(&page->lru, &data->trace_pages);
-               ClearPageLRU(page);
+       spin_lock_irqsave(&trace_buf_lock, flags);
+       len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-               data = max_tr.data[i];
-               page = list_entry(pages.next, struct page, lru);
-               list_del_init(&page->lru);
-               list_add_tail(&page->lru, &data->trace_pages);
-               SetPageLRU(page);
-#endif
-       }
-       tracing_pages_allocated += pages_allocated;
-       global_trace.entries += ENTRIES_PER_PAGE;
+       len = min(len, TRACE_BUF_SIZE-1);
+       trace_buf[len] = 0;
 
-       return 0;
+       size = sizeof(*entry) + len + 1;
+       event = ring_buffer_lock_reserve(tr->buffer, size, &irq_flags);
+       if (!event)
+               goto out_unlock;
+       entry = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type                 = TRACE_PRINT;
+       entry->ip                       = ip;
 
- free_pages:
-       list_for_each_entry_safe(page, tmp, &pages, lru) {
-               list_del_init(&page->lru);
-               __free_page(page);
-       }
-       return -ENOMEM;
+       memcpy(&entry->buf, trace_buf, len);
+       entry->buf[len] = 0;
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+ out_unlock:
+       spin_unlock_irqrestore(&trace_buf_lock, flags);
+
+ out:
+       preempt_enable_notrace();
+
+       return len;
 }
+EXPORT_SYMBOL_GPL(trace_vprintk);
 
-static int trace_free_page(void)
+int __ftrace_printk(unsigned long ip, const char *fmt, ...)
 {
-       struct trace_array_cpu *data;
-       struct page *page;
-       struct list_head *p;
-       int i;
-       int ret = 0;
+       int ret;
+       va_list ap;
 
-       /* free one page from each buffer */
-       for_each_tracing_cpu(i) {
-               data = global_trace.data[i];
-               p = data->trace_pages.next;
-               if (p == &data->trace_pages) {
-                       /* should never happen */
-                       WARN_ON(1);
-                       tracing_disabled = 1;
-                       ret = -1;
-                       break;
-               }
-               page = list_entry(p, struct page, lru);
-               ClearPageLRU(page);
-               list_del(&page->lru);
-               tracing_pages_allocated--;
-               tracing_pages_allocated--;
-               __free_page(page);
+       if (!(trace_flags & TRACE_ITER_PRINTK))
+               return 0;
 
-               tracing_reset(data);
+       va_start(ap, fmt);
+       ret = trace_vprintk(ip, fmt, ap);
+       va_end(ap);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(__ftrace_printk);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-               data = max_tr.data[i];
-               p = data->trace_pages.next;
-               if (p == &data->trace_pages) {
-                       /* should never happen */
-                       WARN_ON(1);
-                       tracing_disabled = 1;
-                       ret = -1;
-                       break;
-               }
-               page = list_entry(p, struct page, lru);
-               ClearPageLRU(page);
-               list_del(&page->lru);
-               __free_page(page);
+static int trace_panic_handler(struct notifier_block *this,
+                              unsigned long event, void *unused)
+{
+       if (ftrace_dump_on_oops)
+               ftrace_dump();
+       return NOTIFY_OK;
+}
 
-               tracing_reset(data);
-#endif
-       }
-       global_trace.entries -= ENTRIES_PER_PAGE;
+static struct notifier_block trace_panic_notifier = {
+       .notifier_call  = trace_panic_handler,
+       .next           = NULL,
+       .priority       = 150   /* priority: INT_MAX >= x >= 0 */
+};
 
-       return ret;
+static int trace_die_handler(struct notifier_block *self,
+                            unsigned long val,
+                            void *data)
+{
+       switch (val) {
+       case DIE_OOPS:
+               if (ftrace_dump_on_oops)
+                       ftrace_dump();
+               break;
+       default:
+               break;
+       }
+       return NOTIFY_OK;
 }
 
-__init static int tracer_alloc_buffers(void)
+static struct notifier_block trace_die_notifier = {
+       .notifier_call = trace_die_handler,
+       .priority = 200
+};
+
+/*
+ * printk is set to max of 1024, we really don't need it that big.
+ * Nothing should be printing 1000 characters anyway.
+ */
+#define TRACE_MAX_PRINT                1000
+
+/*
+ * Define here KERN_TRACE so that we have one place to modify
+ * it if we decide to change what log level the ftrace dump
+ * should be at.
+ */
+#define KERN_TRACE             KERN_INFO
+
+static void
+trace_printk_seq(struct trace_seq *s)
 {
-       struct trace_array_cpu *data;
-       void *array;
-       struct page *page;
-       int pages = 0;
-       int ret = -ENOMEM;
-       int i;
+       /* Probably should print a warning here. */
+       if (s->len >= 1000)
+               s->len = 1000;
 
-       global_trace.ctrl = tracer_enabled;
+       /* should be zero ended, but we are paranoid. */
+       s->buffer[s->len] = 0;
 
-       /* TODO: make the number of buffers hot pluggable with CPUS */
-       tracing_nr_buffers = num_possible_cpus();
-       tracing_buffer_mask = cpu_possible_map;
+       printk(KERN_TRACE "%s", s->buffer);
 
-       /* Allocate the first page for all buffers */
-       for_each_tracing_cpu(i) {
-               data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
-               max_tr.data[i] = &per_cpu(max_data, i);
+       trace_seq_reset(s);
+}
 
-               array = (void *)__get_free_page(GFP_KERNEL);
-               if (array == NULL) {
-                       printk(KERN_ERR "tracer: failed to allocate page"
-                              "for trace buffer!\n");
-                       goto free_buffers;
-               }
+void ftrace_dump(void)
+{
+       static DEFINE_SPINLOCK(ftrace_dump_lock);
+       /* use static because iter can be a bit big for the stack */
+       static struct trace_iterator iter;
+       static cpumask_t mask;
+       static int dump_ran;
+       unsigned long flags;
+       int cnt = 0, cpu;
 
-               /* set the array to the list */
-               INIT_LIST_HEAD(&data->trace_pages);
-               page = virt_to_page(array);
-               list_add(&page->lru, &data->trace_pages);
-               /* use the LRU flag to differentiate the two buffers */
-               ClearPageLRU(page);
+       /* only one dump */
+       spin_lock_irqsave(&ftrace_dump_lock, flags);
+       if (dump_ran)
+               goto out;
 
-               data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
-               max_tr.data[i]->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+       dump_ran = 1;
 
-/* Only allocate if we are actually using the max trace */
-#ifdef CONFIG_TRACER_MAX_TRACE
-               array = (void *)__get_free_page(GFP_KERNEL);
-               if (array == NULL) {
-                       printk(KERN_ERR "tracer: failed to allocate page"
-                              "for trace buffer!\n");
-                       goto free_buffers;
-               }
+       /* No turning back! */
+       ftrace_kill();
 
-               INIT_LIST_HEAD(&max_tr.data[i]->trace_pages);
-               page = virt_to_page(array);
-               list_add(&page->lru, &max_tr.data[i]->trace_pages);
-               SetPageLRU(page);
-#endif
+       for_each_tracing_cpu(cpu) {
+               atomic_inc(&global_trace.data[cpu]->disabled);
        }
 
+       printk(KERN_TRACE "Dumping ftrace buffer:\n");
+
+       iter.tr = &global_trace;
+       iter.trace = current_trace;
+
        /*
-        * Since we allocate by orders of pages, we may be able to
-        * round up a bit.
+        * We need to stop all tracing on all CPUS to read the
+        * the next buffer. This is a bit expensive, but is
+        * not done often. We fill all what we can read,
+        * and then release the locks again.
         */
-       global_trace.entries = ENTRIES_PER_PAGE;
-       pages++;
 
-       while (global_trace.entries < trace_nr_entries) {
-               if (trace_alloc_page())
-                       break;
-               pages++;
-       }
-       max_tr.entries = global_trace.entries;
+       cpus_clear(mask);
 
-       pr_info("tracer: %d pages allocated for %ld",
-               pages, trace_nr_entries);
-       pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE);
-       pr_info("   actual entries %ld\n", global_trace.entries);
+       while (!trace_empty(&iter)) {
 
-       tracer_init_debugfs();
+               if (!cnt)
+                       printk(KERN_TRACE "---------------------------------\n");
 
-       trace_init_cmdlines();
+               cnt++;
 
-       register_tracer(&no_tracer);
-       current_trace = &no_tracer;
+               /* reset all but tr, trace, and overruns */
+               memset(&iter.seq, 0,
+                      sizeof(struct trace_iterator) -
+                      offsetof(struct trace_iterator, seq));
+               iter.iter_flags |= TRACE_FILE_LAT_FMT;
+               iter.pos = -1;
 
-       /* All seems OK, enable tracing */
-       tracing_disabled = 0;
+               if (find_next_entry_inc(&iter) != NULL) {
+                       print_trace_line(&iter);
+                       trace_consume(&iter);
+               }
 
-       return 0;
+               trace_printk_seq(&iter.seq);
+       }
 
- free_buffers:
-       for (i-- ; i >= 0; i--) {
-               struct page *page, *tmp;
-               struct trace_array_cpu *data = global_trace.data[i];
+       if (!cnt)
+               printk(KERN_TRACE "   (ftrace buffer empty)\n");
+       else
+               printk(KERN_TRACE "---------------------------------\n");
 
-               if (data) {
-                       list_for_each_entry_safe(page, tmp,
-                                                &data->trace_pages, lru) {
-                               list_del_init(&page->lru);
-                               __free_page(page);
-                       }
-               }
+ out:
+       spin_unlock_irqrestore(&ftrace_dump_lock, flags);
+}
+
+__init static int tracer_alloc_buffers(void)
+{
+       struct trace_array_cpu *data;
+       int i;
+
+       /* TODO: make the number of buffers hot pluggable with CPUS */
+       tracing_buffer_mask = cpu_possible_map;
+
+       global_trace.buffer = ring_buffer_alloc(trace_buf_size,
+                                                  TRACE_BUFFER_FLAGS);
+       if (!global_trace.buffer) {
+               printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
+               WARN_ON(1);
+               return 0;
+       }
+       global_trace.entries = ring_buffer_size(global_trace.buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
-               data = max_tr.data[i];
-               if (data) {
-                       list_for_each_entry_safe(page, tmp,
-                                                &data->trace_pages, lru) {
-                               list_del_init(&page->lru);
-                               __free_page(page);
-                       }
-               }
+       max_tr.buffer = ring_buffer_alloc(trace_buf_size,
+                                            TRACE_BUFFER_FLAGS);
+       if (!max_tr.buffer) {
+               printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
+               WARN_ON(1);
+               ring_buffer_free(global_trace.buffer);
+               return 0;
+       }
+       max_tr.entries = ring_buffer_size(max_tr.buffer);
+       WARN_ON(max_tr.entries != global_trace.entries);
 #endif
+
+       /* Allocate the first page for all buffers */
+       for_each_tracing_cpu(i) {
+               data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
+               max_tr.data[i] = &per_cpu(max_data, i);
        }
-       return ret;
+
+       trace_init_cmdlines();
+
+       register_tracer(&nop_trace);
+#ifdef CONFIG_BOOT_TRACER
+       register_tracer(&boot_tracer);
+       current_trace = &boot_tracer;
+       current_trace->init(&global_trace);
+#else
+       current_trace = &nop_trace;
+#endif
+
+       /* All seems OK, enable tracing */
+       tracing_disabled = 0;
+
+       atomic_notifier_chain_register(&panic_notifier_list,
+                                      &trace_panic_notifier);
+
+       register_die_notifier(&trace_die_notifier);
+
+       return 0;
 }
-fs_initcall(tracer_alloc_buffers);
+early_initcall(tracer_alloc_buffers);
+fs_initcall(tracer_init_debugfs);