lockd: dont return EAGAIN for a permanent error
[safe/jmp/linux-2.6] / kernel / trace / trace.c
index 9a931c7..868e121 100644 (file)
 #include <linux/percpu.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 "trace.h"
 
 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;
+static cpumask_t __read_mostly         tracing_buffer_mask;
+
+#define for_each_tracing_cpu(cpu)      \
+       for_each_cpu_mask(cpu, tracing_buffer_mask)
+
+static int trace_alloc_page(void);
+static int trace_free_page(void);
+
 static int tracing_disabled = 1;
 
-static long notrace
+static unsigned long tracing_pages_allocated;
+
+long
 ns2usecs(cycle_t nsec)
 {
        nsec += 500;
@@ -42,88 +58,129 @@ ns2usecs(cycle_t nsec)
        return nsec;
 }
 
-static const int time_sync_freq_max = 128;
-static const cycle_t time_sync_thresh = 100000;
-
-static DEFINE_PER_CPU(cycle_t, time_offset);
-static DEFINE_PER_CPU(cycle_t, prev_cpu_time);
-static DEFINE_PER_CPU(int, time_sync_count);
-static DEFINE_PER_CPU(int, time_sync_freq);
+cycle_t ftrace_now(int cpu)
+{
+       return cpu_clock(cpu);
+}
 
 /*
- * Global lock which we take every now and then to synchronize
- * the CPUs time. This method is not warp-safe, but it's good
- * enough to synchronize slowly diverging time sources and thus
- * it's good enough for tracing:
+ * The global_trace is the descriptor that holds the tracing
+ * buffers for the live tracing. For each CPU, it contains
+ * a link list of pages that will store trace entries. The
+ * page descriptor of the pages in the memory is used to hold
+ * the link list by linking the lru item in the page descriptor
+ * to each of the pages in the buffer per CPU.
+ *
+ * For each active CPU there is a data field that holds the
+ * pages for the buffer for that CPU. Each CPU has the same number
+ * of pages allocated for its buffer.
  */
-static DEFINE_SPINLOCK(time_sync_lock);
-static cycle_t prev_global_time;
+static struct trace_array      global_trace;
 
-static notrace cycle_t __ftrace_now_sync(cycles_t time, int cpu)
-{
-       unsigned long flags;
+static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
 
-       spin_lock_irqsave(&time_sync_lock, flags);
+/*
+ * The max_tr is used to snapshot the global_trace when a maximum
+ * latency is reached. Some tracers will use this to store a maximum
+ * trace while it continues examining live traces.
+ *
+ * The buffers for the max_tr are set up the same as the global_trace.
+ * When a snapshot is taken, the link list of the max_tr is swapped
+ * with the link list of the global_trace and the buffers are reset for
+ * the global_trace so the tracing can continue.
+ */
+static struct trace_array      max_tr;
 
-       /*
-        * Update the synchronization frequency:
-        */
-       if (per_cpu(time_sync_freq, cpu) < time_sync_freq_max)
-               per_cpu(time_sync_freq, cpu) *= 2;
-       per_cpu(time_sync_count, cpu) = per_cpu(time_sync_freq, cpu);
+static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
 
-       if (time < prev_global_time) {
-               per_cpu(time_offset, cpu) += prev_global_time - time;
-               time = prev_global_time;
-       } else {
-               prev_global_time = time;
-       }
+/* tracer_enabled is used to toggle activation of a tracer */
+static int                     tracer_enabled = 1;
 
-       spin_unlock_irqrestore(&time_sync_lock, flags);
+/* function tracing enabled */
+int                            ftrace_function_enabled;
 
-       return time;
-}
+/*
+ * 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.
+ */
+static unsigned long           trace_nr_entries = 65536UL;
 
-notrace cycle_t ftrace_now(int cpu)
-{
-       cycle_t prev_cpu_time, time, delta_time;
+/* trace_types holds a link list of available tracers. */
+static struct tracer           *trace_types __read_mostly;
 
-       prev_cpu_time = per_cpu(prev_cpu_time, cpu);
-       time = sched_clock() + per_cpu(time_offset, cpu);
-       delta_time = time-prev_cpu_time;
+/* current_trace points to the tracer that is currently active */
+static struct tracer           *current_trace __read_mostly;
 
-       if (unlikely(delta_time > time_sync_thresh ||
-                               --per_cpu(time_sync_count, cpu) <= 0))
-               time = __ftrace_now_sync(time, cpu);
+/*
+ * max_tracer_type_len is used to simplify the allocating of
+ * buffers to read userspace tracer names. We keep track of
+ * the longest tracer name registered.
+ */
+static int                     max_tracer_type_len;
 
-       return time;
-}
+/*
+ * trace_types_lock is used to protect the trace_types list.
+ * This lock is also used to keep user access serialized.
+ * Accesses from userspace will grab this lock while userspace
+ * activities happen inside the kernel.
+ */
+static DEFINE_MUTEX(trace_types_lock);
 
-static atomic_t                        tracer_counter;
-static struct trace_array      global_trace;
+/* trace_wait is a waitqueue for tasks blocked on trace_poll */
+static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
 
-static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
+/* trace_flags holds iter_ctrl options */
+unsigned long trace_flags = TRACE_ITER_PRINT_PARENT;
 
-static struct trace_array      max_tr;
+static notrace void no_trace_init(struct trace_array *tr)
+{
+       int cpu;
 
-static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
+       ftrace_function_enabled = 0;
+       if(tr->ctrl)
+               for_each_online_cpu(cpu)
+                       tracing_reset(tr->data[cpu]);
+       tracer_enabled = 0;
+}
 
-static int                     tracer_enabled;
-static unsigned long           trace_nr_entries = 16384UL;
+/* dummy trace to disable tracing */
+static struct tracer no_tracer __read_mostly = {
+       .name           = "none",
+       .init           = no_trace_init
+};
 
-static struct tracer           *trace_types __read_mostly;
-static struct tracer           *current_trace __read_mostly;
-static int                     max_tracer_type_len;
 
-static DEFINE_MUTEX(trace_types_lock);
+/**
+ * trace_wake_up - wake up tasks waiting for trace input
+ *
+ * Simply wakes up any task that is blocked on the trace_wait
+ * queue. These is used with trace_poll for tasks polling the trace.
+ */
+void trace_wake_up(void)
+{
+       /*
+        * The runqueue_is_locked() can fail, but this is the best we
+        * have for now:
+        */
+       if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked())
+               wake_up(&trace_wait);
+}
 
 #define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))
 
 static int __init set_nr_entries(char *str)
 {
+       unsigned long nr_entries;
+       int ret;
+
        if (!str)
                return 0;
-       trace_nr_entries = simple_strtoul(str, &str, 0);
+       ret = strict_strtoul(str, 0, &nr_entries);
+       /* nr_entries can not be zero */
+       if (ret < 0 || nr_entries == 0)
+               return 0;
+       trace_nr_entries = nr_entries;
        return 1;
 }
 __setup("trace_entries=", set_nr_entries);
@@ -133,15 +190,14 @@ unsigned long nsecs_to_usecs(unsigned long nsecs)
        return nsecs / 1000;
 }
 
-enum trace_type {
-       __TRACE_FIRST_TYPE = 0,
-
-       TRACE_FN,
-       TRACE_CTX,
-
-       __TRACE_LAST_TYPE
-};
-
+/*
+ * 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,
@@ -149,35 +205,46 @@ enum trace_flag_type {
        TRACE_FLAG_SOFTIRQ              = 0x08,
 };
 
-enum trace_iterator_flags {
-       TRACE_ITER_PRINT_PARENT         = 0x01,
-       TRACE_ITER_SYM_OFFSET           = 0x02,
-       TRACE_ITER_SYM_ADDR             = 0x04,
-       TRACE_ITER_VERBOSE              = 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 above */
+/* These must match the bit postions in trace_iterator_flags */
 static const char *trace_options[] = {
        "print-parent",
        "sym-offset",
        "sym-addr",
        "verbose",
+       "raw",
+       "hex",
+       "bin",
+       "block",
+       "stacktrace",
+       "sched-tree",
        NULL
 };
 
-static unsigned trace_flags;
-
-static DEFINE_SPINLOCK(ftrace_max_lock);
+/*
+ * ftrace_max_lock is used to protect the swapping of buffers
+ * when taking a max snapshot. The buffers themselves are
+ * protected by per_cpu spinlocks. But the action of the swap
+ * needs its own lock.
+ *
+ * This is defined as a raw_spinlock_t in order to help
+ * with performance when lockdep debugging is enabled.
+ */
+static raw_spinlock_t ftrace_max_lock =
+       (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
 
 /*
  * Copy the new maximum trace into the separate maximum-trace
  * structure. (this way the maximum trace is permanently saved,
  * for later retrieval via /debugfs/tracing/latency_trace)
  */
-static notrace void
+static void
 __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
        struct trace_array_cpu *data = tr->data[cpu];
@@ -199,24 +266,45 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
        tracing_record_cmdline(current);
 }
 
-void check_pages(struct trace_array_cpu *data)
+#define CHECK_COND(cond)                       \
+       if (unlikely(cond)) {                   \
+               tracing_disabled = 1;           \
+               WARN_ON(1);                     \
+               return -1;                      \
+       }
+
+/**
+ * check_pages - integrity check of trace buffers
+ *
+ * As a safty measure we check to make sure the data pages have not
+ * been corrupted.
+ */
+int 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);
+       CHECK_COND(data->trace_pages.next->prev != &data->trace_pages);
+       CHECK_COND(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);
+               CHECK_COND(page->lru.next->prev != &page->lru);
+               CHECK_COND(page->lru.prev->next != &page->lru);
        }
+
+       return 0;
 }
 
+/**
+ * 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;
 
@@ -226,7 +314,18 @@ void *head_page(struct trace_array_cpu *data)
        return page_address(page);
 }
 
-static notrace int
+/**
+ * trace_seq_printf - sequence printing of trace information
+ * @s: trace sequence descriptor
+ * @fmt: printf format string
+ *
+ * The tracer may use either sequence operations or its own
+ * copy to user routines. To simplify formating of a trace
+ * trace_seq_printf is used to store strings into a special
+ * buffer (@s). Then the output may be either used by
+ * the sequencer or pulled into another buffer.
+ */
+int
 trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
 {
        int len = (PAGE_SIZE - 1) - s->len;
@@ -241,7 +340,7 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
        va_end(ap);
 
        /* If we can't write it all, don't bother writing anything */
-       if (ret > len)
+       if (ret >= len)
                return 0;
 
        s->len += ret;
@@ -249,7 +348,17 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
        return len;
 }
 
-static notrace int
+/**
+ * trace_seq_puts - trace sequence printing of simple string
+ * @s: trace sequence descriptor
+ * @str: simple string to record
+ *
+ * The tracer may use either the sequence operations or its own
+ * copy to user routines. This function records a simple string
+ * into a special buffer (@s) for later retrieval by a sequencer
+ * or other mechanism.
+ */
+static int
 trace_seq_puts(struct trace_seq *s, const char *str)
 {
        int len = strlen(str);
@@ -263,7 +372,7 @@ trace_seq_puts(struct trace_seq *s, const char *str)
        return len;
 }
 
-static notrace int
+static int
 trace_seq_putc(struct trace_seq *s, unsigned char c)
 {
        if (s->len >= (PAGE_SIZE - 1))
@@ -274,13 +383,73 @@ trace_seq_putc(struct trace_seq *s, unsigned char c)
        return 1;
 }
 
-static notrace void
+static int
+trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
+{
+       if (len > ((PAGE_SIZE - 1) - s->len))
+               return 0;
+
+       memcpy(s->buffer + s->len, mem, len);
+       s->len += len;
+
+       return len;
+}
+
+#define HEX_CHARS 17
+static const char hex2asc[] = "0123456789abcdef";
+
+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++] = ' ';
+
+       return trace_seq_putmem(s, hex, j);
+}
+
+static void
 trace_seq_reset(struct trace_seq *s)
 {
        s->len = 0;
+       s->readpos = 0;
+}
+
+ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
+{
+       int len;
+       int ret;
+
+       if (s->len <= s->readpos)
+               return -EBUSY;
+
+       len = s->len - s->readpos;
+       if (cnt > len)
+               cnt = len;
+       ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
+       if (ret)
+               return -EFAULT;
+
+       s->readpos += len;
+       return cnt;
 }
 
-static notrace void
+static void
 trace_print_seq(struct seq_file *m, struct trace_seq *s)
 {
        int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
@@ -291,7 +460,14 @@ trace_print_seq(struct seq_file *m, struct trace_seq *s)
        trace_seq_reset(s);
 }
 
-notrace static void
+/*
+ * 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;
@@ -312,23 +488,32 @@ flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
        check_pages(tr2);
 }
 
-notrace void
+/**
+ * update_max_tr - snapshot all trace buffers from global_trace to max_tr
+ * @tr: tracer
+ * @tsk: the task with the latency
+ * @cpu: The cpu that initiated the trace.
+ *
+ * Flip the buffers between the @tr and the max_tr and record information
+ * about which task was the cause of this latency.
+ */
+void
 update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
        struct trace_array_cpu *data;
        int i;
 
        WARN_ON_ONCE(!irqs_disabled());
-       spin_lock(&ftrace_max_lock);
+       __raw_spin_lock(&ftrace_max_lock);
        /* clear out all the previous traces */
-       for_each_possible_cpu(i) {
+       for_each_tracing_cpu(i) {
                data = tr->data[i];
                flip_trace(max_tr.data[i], data);
                tracing_reset(data);
        }
 
        __update_max_tr(tr, tsk, cpu);
-       spin_unlock(&ftrace_max_lock);
+       __raw_spin_unlock(&ftrace_max_lock);
 }
 
 /**
@@ -336,25 +521,33 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
  * @tr - tracer
  * @tsk - task with the latency
  * @cpu - the cpu of the buffer to copy.
+ *
+ * Flip the trace of a single CPU buffer between the @tr and the max_tr.
  */
-notrace void
+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;
 
        WARN_ON_ONCE(!irqs_disabled());
-       spin_lock(&ftrace_max_lock);
-       for_each_possible_cpu(i)
+       __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);
 
        __update_max_tr(tr, tsk, cpu);
-       spin_unlock(&ftrace_max_lock);
+       __raw_spin_unlock(&ftrace_max_lock);
 }
 
+/**
+ * register_tracer - register a tracer with the ftrace system.
+ * @type - the plugin for the tracer
+ *
+ * Register a new plugin tracer.
+ */
 int register_tracer(struct tracer *type)
 {
        struct tracer *t;
@@ -391,7 +584,7 @@ int register_tracer(struct tracer *type)
                 * internal tracing to verify that everything is in order.
                 * If we fail, we do not register this tracer.
                 */
-               for_each_possible_cpu(i) {
+               for_each_tracing_cpu(i) {
                        data = tr->data[i];
                        if (!head_page(data))
                                continue;
@@ -410,7 +603,7 @@ int register_tracer(struct tracer *type)
                        goto out;
                }
                /* Only reset on passing, to avoid touching corrupted buffers */
-               for_each_possible_cpu(i) {
+               for_each_tracing_cpu(i) {
                        data = tr->data[i];
                        if (!head_page(data))
                                continue;
@@ -460,62 +653,24 @@ void unregister_tracer(struct tracer *type)
        mutex_unlock(&trace_types_lock);
 }
 
-notrace void tracing_reset(struct trace_array_cpu *data)
+void tracing_reset(struct trace_array_cpu *data)
 {
        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;
 }
 
-#ifdef CONFIG_FTRACE
-static notrace 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;
-
-       if (unlikely(!tracer_enabled))
-               return;
-
-       local_irq_save(flags);
-       cpu = raw_smp_processor_id();
-       data = tr->data[cpu];
-       disabled = atomic_inc_return(&data->disabled);
-
-       if (likely(disabled == 1))
-               ftrace(tr, data, ip, parent_ip, flags);
-
-       atomic_dec(&data->disabled);
-       local_irq_restore(flags);
-}
-
-static struct ftrace_ops trace_ops __read_mostly =
-{
-       .func = function_trace_call,
-};
-#endif
-
-notrace void tracing_start_function_trace(void)
-{
-       register_ftrace_function(&trace_ops);
-}
-
-notrace void tracing_stop_function_trace(void)
-{
-       unregister_ftrace_function(&trace_ops);
-}
-
 #define SAVED_CMDLINES 128
 static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
 static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
 static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
 static int cmdline_idx;
 static DEFINE_SPINLOCK(trace_cmdline_lock);
-atomic_t trace_record_cmdline_disabled;
+
+/* temporary disable recording */
+atomic_t trace_record_cmdline_disabled __read_mostly;
 
 static void trace_init_cmdlines(void)
 {
@@ -524,9 +679,9 @@ static void trace_init_cmdlines(void)
        cmdline_idx = 0;
 }
 
-notrace void trace_stop_cmdline_recording(void);
+void trace_stop_cmdline_recording(void);
 
-static notrace void trace_save_cmdline(struct task_struct *tsk)
+static void trace_save_cmdline(struct task_struct *tsk)
 {
        unsigned map;
        unsigned idx;
@@ -561,7 +716,7 @@ static notrace void trace_save_cmdline(struct task_struct *tsk)
        spin_unlock(&trace_cmdline_lock);
 }
 
-static notrace char *trace_find_cmdline(int pid)
+static char *trace_find_cmdline(int pid)
 {
        char *cmdline = "<...>";
        unsigned map;
@@ -582,7 +737,7 @@ static notrace char *trace_find_cmdline(int pid)
        return cmdline;
 }
 
-notrace void tracing_record_cmdline(struct task_struct *tsk)
+void tracing_record_cmdline(struct task_struct *tsk)
 {
        if (atomic_read(&trace_record_cmdline_disabled))
                return;
@@ -590,7 +745,7 @@ notrace void tracing_record_cmdline(struct task_struct *tsk)
        trace_save_cmdline(tsk);
 }
 
-static inline notrace struct list_head *
+static inline struct list_head *
 trace_next_list(struct trace_array_cpu *data, struct list_head *next)
 {
        /*
@@ -604,7 +759,7 @@ trace_next_list(struct trace_array_cpu *data, struct list_head *next)
        return next;
 }
 
-static inline notrace void *
+static inline void *
 trace_next_page(struct trace_array_cpu *data, void *addr)
 {
        struct list_head *next;
@@ -618,7 +773,7 @@ trace_next_page(struct trace_array_cpu *data, void *addr)
        return page_address(page);
 }
 
-static inline notrace struct trace_entry *
+static inline struct trace_entry *
 tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data)
 {
        unsigned long idx, idx_next;
@@ -640,6 +795,7 @@ tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data)
        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 =
@@ -653,7 +809,7 @@ tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data)
        return entry;
 }
 
-static inline notrace void
+static inline void
 tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
 {
        struct task_struct *tsk = current;
@@ -661,9 +817,8 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
 
        pc = preempt_count();
 
-       entry->idx              = atomic_inc_return(&tracer_counter);
        entry->preempt_count    = pc & 0xff;
-       entry->pid              = tsk->pid;
+       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) |
                ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
@@ -671,30 +826,135 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
                (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
 }
 
-notrace void
-ftrace(struct trace_array *tr, struct trace_array_cpu *data,
-       unsigned long ip, unsigned long parent_ip, 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)
 {
        struct trace_entry *entry;
+       unsigned long irq_flags;
 
-       spin_lock(&data->lock);
+       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;
-       spin_unlock(&data->lock);
+       __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);
 }
 
-notrace void
+#ifdef CONFIG_MMIOTRACE
+void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data,
+                                               struct mmiotrace_rw *rw)
+{
+       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_RW;
+       entry->mmiorw           = *rw;
+
+       __raw_spin_unlock(&data->lock);
+       raw_local_irq_restore(irq_flags);
+
+       trace_wake_up();
+}
+
+void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data,
+                                               struct mmiotrace_map *map)
+{
+       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();
+}
+#endif
+
+void __trace_stack(struct trace_array *tr,
+                  struct trace_array_cpu *data,
+                  unsigned long flags,
+                  int skip)
+{
+       struct trace_entry *entry;
+       struct stack_trace trace;
+
+       if (!(trace_flags & TRACE_ITER_STACKTRACE))
+               return;
+
+       entry                   = tracing_get_trace_entry(tr, data);
+       tracing_generic_entry_update(entry, flags);
+       entry->type             = TRACE_STACK;
+
+       memset(&entry->stack, 0, sizeof(entry->stack));
+
+       trace.nr_entries        = 0;
+       trace.max_entries       = FTRACE_STACK_ENTRIES;
+       trace.skip              = skip;
+       trace.entries           = entry->stack.caller;
+
+       save_stack_trace(&trace);
+}
+
+void
+__trace_special(void *__tr, void *__data,
+               unsigned long arg1, unsigned long arg2, unsigned long arg3)
+{
+       struct trace_array_cpu *data = __data;
+       struct trace_array *tr = __tr;
+       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_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);
+
+       trace_wake_up();
+}
+
+void
 tracing_sched_switch_trace(struct trace_array *tr,
                           struct trace_array_cpu *data,
-                          struct task_struct *prev, struct task_struct *next,
+                          struct task_struct *prev,
+                          struct task_struct *next,
                           unsigned long flags)
 {
        struct trace_entry *entry;
+       unsigned long irq_flags;
 
-       spin_lock(&data->lock);
+       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;
@@ -703,9 +963,112 @@ tracing_sched_switch_trace(struct trace_array *tr,
        entry->ctx.prev_state   = prev->state;
        entry->ctx.next_pid     = next->pid;
        entry->ctx.next_prio    = next->prio;
-       spin_unlock(&data->lock);
+       entry->ctx.next_state   = next->state;
+       __trace_stack(tr, data, flags, 5);
+       __raw_spin_unlock(&data->lock);
+       raw_local_irq_restore(irq_flags);
 }
 
+void
+tracing_sched_wakeup_trace(struct trace_array *tr,
+                          struct trace_array_cpu *data,
+                          struct task_struct *wakee,
+                          struct task_struct *curr,
+                          unsigned long flags)
+{
+       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, 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);
+
+       trace_wake_up();
+}
+
+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;
+
+       if (tracing_disabled || current_trace == &no_tracer || !tr->ctrl)
+               return;
+
+       local_irq_save(flags);
+       cpu = raw_smp_processor_id();
+       data = tr->data[cpu];
+       disabled = atomic_inc_return(&data->disabled);
+
+       if (likely(disabled == 1))
+               __trace_special(tr, data, arg1, arg2, arg3);
+
+       atomic_dec(&data->disabled);
+       local_irq_restore(flags);
+}
+
+#ifdef CONFIG_FTRACE
+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;
+
+       if (unlikely(!ftrace_function_enabled))
+               return;
+
+       if (skip_trace(ip))
+               return;
+
+       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);
+
+       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)
+{
+       ftrace_function_enabled = 0;
+       register_ftrace_function(&trace_ops);
+       if (tracer_enabled)
+               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,
 };
@@ -736,16 +1099,11 @@ trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data,
 
        array = page_address(page);
 
-       /* Still possible to catch up to the tail */
-       if (iter->next_idx[cpu] && array == data->trace_tail &&
-           iter->next_page_idx[cpu] == data->trace_tail_idx)
-               return NULL;
-
        WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE);
        return &array[iter->next_page_idx[cpu]];
 }
 
-static struct notrace trace_entry *
+static struct trace_entry *
 find_next_entry(struct trace_iterator *iter, int *ent_cpu)
 {
        struct trace_array *tr = iter->tr;
@@ -753,12 +1111,14 @@ find_next_entry(struct trace_iterator *iter, int *ent_cpu)
        int next_cpu = -1;
        int cpu;
 
-       for_each_possible_cpu(cpu) {
+       for_each_tracing_cpu(cpu) {
                if (!head_page(tr->data[cpu]))
                        continue;
                ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
-               if (ent &&
-                   (!next || (long)(next->idx - ent->idx) > 0)) {
+               /*
+                * Pick the entry with the smallest timestamp:
+                */
+               if (ent && (!next || ent->t < next->t)) {
                        next = ent;
                        next_cpu = cpu;
                }
@@ -770,12 +1130,12 @@ find_next_entry(struct trace_iterator *iter, int *ent_cpu)
        return next;
 }
 
-static notrace void
-trace_iterator_increment(struct trace_iterator *iter)
+static void trace_iterator_increment(struct trace_iterator *iter)
 {
        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];
 
@@ -785,8 +1145,7 @@ trace_iterator_increment(struct trace_iterator *iter)
        }
 }
 
-static notrace void
-trace_consume(struct trace_iterator *iter)
+static void trace_consume(struct trace_iterator *iter)
 {
        struct trace_array_cpu *data = iter->tr->data[iter->cpu];
 
@@ -800,12 +1159,9 @@ trace_consume(struct trace_iterator *iter)
        if (data->trace_head == data->trace_tail &&
            data->trace_head_idx == data->trace_tail_idx)
                data->trace_idx = 0;
-
-       trace_iterator_increment(iter);
 }
 
-static notrace void *
-find_next_entry_inc(struct trace_iterator *iter)
+static void *find_next_entry_inc(struct trace_iterator *iter)
 {
        struct trace_entry *next;
        int next_cpu = -1;
@@ -824,7 +1180,7 @@ find_next_entry_inc(struct trace_iterator *iter)
        return next ? iter : NULL;
 }
 
-static notrace void *s_next(struct seq_file *m, void *v, loff_t *pos)
+static void *s_next(struct seq_file *m, void *v, loff_t *pos)
 {
        struct trace_iterator *iter = m->private;
        void *last_ent = iter->ent;
@@ -862,8 +1218,10 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 
        mutex_lock(&trace_types_lock);
 
-       if (!current_trace || current_trace != iter->trace)
+       if (!current_trace || current_trace != iter->trace) {
+               mutex_unlock(&trace_types_lock);
                return NULL;
+       }
 
        atomic_inc(&trace_record_cmdline_disabled);
 
@@ -878,7 +1236,7 @@ static void *s_start(struct seq_file *m, loff_t *pos)
                iter->prev_ent = NULL;
                iter->prev_cpu = -1;
 
-               for_each_possible_cpu(i) {
+               for_each_tracing_cpu(i) {
                        iter->next_idx[i] = 0;
                        iter->next_page[i] = NULL;
                }
@@ -907,6 +1265,20 @@ static void s_stop(struct seq_file *m, void *p)
        mutex_unlock(&trace_types_lock);
 }
 
+#define KRETPROBE_MSG "[unknown/kretprobe'd]"
+
+#ifdef CONFIG_KRETPROBES
+static inline int kretprobed(unsigned long addr)
+{
+       return addr == (unsigned long)kretprobe_trampoline;
+}
+#else
+static inline int kretprobed(unsigned long addr)
+{
+       return 0;
+}
+#endif /* CONFIG_KRETPROBES */
+
 static int
 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 {
@@ -939,7 +1311,7 @@ seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 # define IP_FMT "%016lx"
 #endif
 
-static notrace int
+static int
 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 {
        int ret;
@@ -960,7 +1332,7 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
        return ret;
 }
 
-static notrace void print_lat_help_header(struct seq_file *m)
+static void print_lat_help_header(struct seq_file *m)
 {
        seq_puts(m, "#                _------=> CPU#            \n");
        seq_puts(m, "#               / _-----=> irqs-off        \n");
@@ -973,14 +1345,14 @@ static notrace void print_lat_help_header(struct seq_file *m)
        seq_puts(m, "#     \\   /    |||||   \\   |   /           \n");
 }
 
-static notrace void print_func_help_header(struct seq_file *m)
+static void print_func_help_header(struct seq_file *m)
 {
        seq_puts(m, "#           TASK-PID   CPU#    TIMESTAMP  FUNCTION\n");
        seq_puts(m, "#              | |      |          |         |\n");
 }
 
 
-static notrace void
+static void
 print_trace_header(struct seq_file *m, struct trace_iterator *iter)
 {
        unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
@@ -995,7 +1367,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
        if (type)
                name = type->name;
 
-       for_each_possible_cpu(cpu) {
+       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)
@@ -1019,7 +1391,7 @@ 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",
@@ -1051,7 +1423,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
        seq_puts(m, "\n");
 }
 
-static notrace void
+static void
 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 {
        int hardirq, softirq;
@@ -1067,12 +1439,12 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 
        hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
        softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
-       if (hardirq && softirq)
+       if (hardirq && softirq) {
                trace_seq_putc(s, 'H');
-       else {
-               if (hardirq)
+       else {
+               if (hardirq) {
                        trace_seq_putc(s, 'h');
-               else {
+               else {
                        if (softirq)
                                trace_seq_putc(s, 's');
                        else
@@ -1088,7 +1460,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 
 unsigned long preempt_mark_thresh = 100;
 
-static notrace void
+static void
 lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
                    unsigned long rel_usecs)
 {
@@ -1103,7 +1475,7 @@ lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
 
 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 
-static notrace void
+static int
 print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 {
        struct trace_seq *s = &iter->seq;
@@ -1114,7 +1486,9 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
        unsigned long abs_usecs;
        unsigned long rel_usecs;
        char *comm;
-       int S;
+       int S, T;
+       int i;
+       unsigned state;
 
        if (!next_entry)
                next_entry = entry;
@@ -1140,55 +1514,49 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
        case TRACE_FN:
                seq_print_ip_sym(s, entry->fn.ip, sym_flags);
                trace_seq_puts(s, " (");
-               seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
+               if (kretprobed(entry->fn.parent_ip))
+                       trace_seq_puts(s, KRETPROBE_MSG);
+               else
+                       seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
                trace_seq_puts(s, ")\n");
                break;
        case TRACE_CTX:
-               S = entry->ctx.prev_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.prev_state] : 'X';
+       case TRACE_WAKE:
+               T = entry->ctx.next_state < sizeof(state_to_char) ?
+                       state_to_char[entry->ctx.next_state] : 'X';
+
+               state = entry->ctx.prev_state ? __ffs(entry->ctx.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, " %d:%d:%c --> %d:%d %s\n",
+               trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n",
                                 entry->ctx.prev_pid,
                                 entry->ctx.prev_prio,
-                                S,
+                                S, entry->type == TRACE_CTX ? "==>" : "  +",
                                 entry->ctx.next_pid,
                                 entry->ctx.next_prio,
-                                comm);
+                                T, comm);
+               break;
+       case TRACE_SPECIAL:
+               trace_seq_printf(s, "# %ld %ld %ld\n",
+                                entry->special.arg1,
+                                entry->special.arg2,
+                                entry->special.arg3);
+               break;
+       case TRACE_STACK:
+               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);
+               }
+               trace_seq_puts(s, "\n");
                break;
        default:
                trace_seq_printf(s, "Unknown type %d\n", entry->type);
        }
+       return 1;
 }
 
-static notrace void sync_time_offset(struct trace_iterator *iter)
-{
-       struct trace_array_cpu *prev_array, *array;
-       struct trace_entry *prev_entry, *entry;
-       cycle_t prev_t, t;
-
-       entry = iter->ent;
-       prev_entry = iter->prev_ent;
-       if (!prev_entry)
-               return;
-
-       prev_array = iter->tr->data[iter->prev_cpu];
-       array = iter->tr->data[iter->cpu];
-
-       prev_t = prev_entry->t + prev_array->time_offset;
-       t = entry->t + array->time_offset;
-
-       /*
-        * If time goes backwards we increase the offset of
-        * the current array, to not have observable time warps.
-        * This will quickly synchronize the time offsets of
-        * multiple CPUs:
-        */
-       if (t < prev_t)
-               array->time_offset += prev_t - t;
-}
-
-static notrace int
-print_trace_fmt(struct trace_iterator *iter)
+static int print_trace_fmt(struct trace_iterator *iter)
 {
        struct trace_seq *s = &iter->seq;
        unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
@@ -1197,58 +1565,234 @@ print_trace_fmt(struct trace_iterator *iter)
        unsigned long long t;
        unsigned long secs;
        char *comm;
-       int S;
        int ret;
+       int S, T;
+       int i;
 
-       sync_time_offset(iter);
        entry = iter->ent;
 
        comm = trace_find_cmdline(iter->ent->pid);
 
-       t = ns2usecs(entry->t + iter->tr->data[iter->cpu]->time_offset);
+       t = ns2usecs(entry->t);
        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);
-       if (!ret)
-               return 0;
-       ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
-       if (!ret)
-               return 0;
+       ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
+       if (!ret)
+               return 0;
+       ret = trace_seq_printf(s, "[%02d] ", iter->cpu);
+       if (!ret)
+               return 0;
+       ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
+       if (!ret)
+               return 0;
+
+       switch (entry->type) {
+       case TRACE_FN:
+               ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+               if (!ret)
+                       return 0;
+               if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
+                                               entry->fn.parent_ip) {
+                       ret = trace_seq_printf(s, " <-");
+                       if (!ret)
+                               return 0;
+                       if (kretprobed(entry->fn.parent_ip))
+                               ret = trace_seq_puts(s, KRETPROBE_MSG);
+                       else
+                               ret = seq_print_ip_sym(s, entry->fn.parent_ip,
+                                                      sym_flags);
+                       if (!ret)
+                               return 0;
+               }
+               ret = trace_seq_printf(s, "\n");
+               if (!ret)
+                       return 0;
+               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,
+                                      S,
+                                      entry->type == TRACE_CTX ? "==>" : "  +",
+                                      entry->ctx.next_pid,
+                                      entry->ctx.next_prio,
+                                      T);
+               if (!ret)
+                       return 0;
+               break;
+       case TRACE_SPECIAL:
+               ret = trace_seq_printf(s, "# %ld %ld %ld\n",
+                                entry->special.arg1,
+                                entry->special.arg2,
+                                entry->special.arg3);
+               if (!ret)
+                       return 0;
+               break;
+       case TRACE_STACK:
+               for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+                       if (i) {
+                               ret = trace_seq_puts(s, " <= ");
+                               if (!ret)
+                                       return 0;
+                       }
+                       ret = seq_print_ip_sym(s, entry->stack.caller[i],
+                                              sym_flags);
+                       if (!ret)
+                               return 0;
+               }
+               ret = trace_seq_puts(s, "\n");
+               if (!ret)
+                       return 0;
+               break;
+       }
+       return 1;
+}
+
+static int print_raw_fmt(struct trace_iterator *iter)
+{
+       struct trace_seq *s = &iter->seq;
+       struct trace_entry *entry;
+       int ret;
+       int S, T;
+
+       entry = iter->ent;
+
+       ret = trace_seq_printf(s, "%d %d %llu ",
+               entry->pid, iter->cpu, entry->t);
+       if (!ret)
+               return 0;
+
+       switch (entry->type) {
+       case TRACE_FN:
+               ret = trace_seq_printf(s, "%x %x\n",
+                                       entry->fn.ip, entry->fn.parent_ip);
+               if (!ret)
+                       return 0;
+               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';
+               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,
+                                      S,
+                                      entry->ctx.next_pid,
+                                      entry->ctx.next_prio,
+                                      T);
+               if (!ret)
+                       return 0;
+               break;
+       case TRACE_SPECIAL:
+       case TRACE_STACK:
+               ret = trace_seq_printf(s, "# %ld %ld %ld\n",
+                                entry->special.arg1,
+                                entry->special.arg2,
+                                entry->special.arg3);
+               if (!ret)
+                       return 0;
+               break;
+       }
+       return 1;
+}
+
+#define SEQ_PUT_FIELD_RET(s, x)                                \
+do {                                                   \
+       if (!trace_seq_putmem(s, &(x), sizeof(x)))      \
+               return 0;                               \
+} while (0)
+
+#define SEQ_PUT_HEX_FIELD_RET(s, x)                    \
+do {                                                   \
+       if (!trace_seq_putmem_hex(s, &(x), sizeof(x)))  \
+               return 0;                               \
+} while (0)
+
+static int print_hex_fmt(struct trace_iterator *iter)
+{
+       struct trace_seq *s = &iter->seq;
+       unsigned char newline = '\n';
+       struct trace_entry *entry;
+       int S, T;
+
+       entry = iter->ent;
+
+       SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
+       SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
+       SEQ_PUT_HEX_FIELD_RET(s, entry->t);
+
+       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);
+               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';
+               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, 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, 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);
+               break;
+       }
+       SEQ_PUT_FIELD_RET(s, newline);
+
+       return 1;
+}
+
+static int print_bin_fmt(struct trace_iterator *iter)
+{
+       struct trace_seq *s = &iter->seq;
+       struct trace_entry *entry;
+
+       entry = iter->ent;
+
+       SEQ_PUT_FIELD_RET(s, entry->pid);
+       SEQ_PUT_FIELD_RET(s, entry->cpu);
+       SEQ_PUT_FIELD_RET(s, entry->t);
 
        switch (entry->type) {
        case TRACE_FN:
-               ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags);
-               if (!ret)
-                       return 0;
-               if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
-                                               entry->fn.parent_ip) {
-                       ret = trace_seq_printf(s, " <-");
-                       if (!ret)
-                               return 0;
-                       ret = seq_print_ip_sym(s, entry->fn.parent_ip,
-                                              sym_flags);
-                       if (!ret)
-                               return 0;
-               }
-               ret = trace_seq_printf(s, "\n");
-               if (!ret)
-                       return 0;
+               SEQ_PUT_FIELD_RET(s, entry->fn.ip);
+               SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip);
                break;
        case TRACE_CTX:
-               S = entry->ctx.prev_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.prev_state] : 'X';
-               ret = trace_seq_printf(s, " %d:%d:%c ==> %d:%d\n",
-                                      entry->ctx.prev_pid,
-                                      entry->ctx.prev_prio,
-                                      S,
-                                      entry->ctx.next_pid,
-                                      entry->ctx.next_prio);
-               if (!ret)
-                       return 0;
+               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);
+               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);
                break;
        }
        return 1;
@@ -1259,7 +1803,7 @@ static int trace_empty(struct trace_iterator *iter)
        struct trace_array_cpu *data;
        int cpu;
 
-       for_each_possible_cpu(cpu) {
+       for_each_tracing_cpu(cpu) {
                data = iter->tr->data[cpu];
 
                if (head_page(data) && data->trace_idx &&
@@ -1270,6 +1814,26 @@ static int trace_empty(struct trace_iterator *iter)
        return 1;
 }
 
+static int print_trace_line(struct trace_iterator *iter)
+{
+       if (iter->trace && iter->trace->print_line)
+               return iter->trace->print_line(iter);
+
+       if (trace_flags & TRACE_ITER_BIN)
+               return print_bin_fmt(iter);
+
+       if (trace_flags & TRACE_ITER_HEX)
+               return print_hex_fmt(iter);
+
+       if (trace_flags & TRACE_ITER_RAW)
+               return print_raw_fmt(iter);
+
+       if (iter->iter_flags & TRACE_FILE_LAT_FMT)
+               return print_lat_fmt(iter, iter->idx, iter->cpu);
+
+       return print_trace_fmt(iter);
+}
+
 static int s_show(struct seq_file *m, void *v)
 {
        struct trace_iterator *iter = v;
@@ -1291,10 +1855,7 @@ static int s_show(struct seq_file *m, void *v)
                                print_func_help_header(m);
                }
        } else {
-               if (iter->iter_flags & TRACE_FILE_LAT_FMT)
-                       print_lat_fmt(iter, iter->idx, iter->cpu);
-               else
-                       print_trace_fmt(iter);
+               print_trace_line(iter);
                trace_print_seq(m, &iter->seq);
        }
 
@@ -1308,7 +1869,7 @@ static struct seq_operations tracer_seq_ops = {
        .show           = s_show,
 };
 
-static struct trace_iterator notrace *
+static struct trace_iterator *
 __tracing_open(struct inode *inode, struct file *file, int *ret)
 {
        struct trace_iterator *iter;
@@ -1339,8 +1900,10 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
                m->private = iter;
 
                /* stop the trace while dumping */
-               if (iter->tr->ctrl)
+               if (iter->tr->ctrl) {
                        tracer_enabled = 0;
+                       ftrace_function_enabled = 0;
+               }
 
                if (iter->trace && iter->trace->open)
                        iter->trace->open(iter);
@@ -1373,8 +1936,14 @@ int tracing_release(struct inode *inode, struct file *file)
                iter->trace->close(iter);
 
        /* reenable tracing if it was previously enabled */
-       if (iter->tr->ctrl)
+       if (iter->tr->ctrl) {
                tracer_enabled = 1;
+               /*
+                * It is safe to enable function tracing even if it
+                * isn't used
+                */
+               ftrace_function_enabled = 1;
+       }
        mutex_unlock(&trace_types_lock);
 
        seq_release(inode, file);
@@ -1405,7 +1974,7 @@ static int tracing_lt_open(struct inode *inode, struct file *file)
 }
 
 
-static notrace void *
+static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
        struct tracer *t = m->private;
@@ -1491,9 +2060,102 @@ static struct file_operations tracing_lt_fops = {
 };
 
 static struct file_operations show_traces_fops = {
-       .open = show_traces_open,
-       .read = seq_read,
-       .release = seq_release,
+       .open           = show_traces_open,
+       .read           = seq_read,
+       .release        = seq_release,
+};
+
+/*
+ * Only trace on a CPU if the bitmask is set:
+ */
+static cpumask_t tracing_cpumask = CPU_MASK_ALL;
+
+/*
+ * When tracing/tracing_cpu_mask is modified then this holds
+ * the new bitmask we are about to install:
+ */
+static cpumask_t tracing_cpumask_new;
+
+/*
+ * The tracer itself will not take this lock, but still we want
+ * to provide a consistent cpumask to user-space:
+ */
+static DEFINE_MUTEX(tracing_cpumask_update_lock);
+
+/*
+ * Temporary storage for the character representation of the
+ * CPU bitmask (and one more byte for the newline):
+ */
+static char mask_str[NR_CPUS + 1];
+
+static ssize_t
+tracing_cpumask_read(struct file *filp, char __user *ubuf,
+                    size_t count, loff_t *ppos)
+{
+       int len;
+
+       mutex_lock(&tracing_cpumask_update_lock);
+
+       len = cpumask_scnprintf(mask_str, count, tracing_cpumask);
+       if (count - len < 2) {
+               count = -EINVAL;
+               goto out_err;
+       }
+       len += sprintf(mask_str + len, "\n");
+       count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1);
+
+out_err:
+       mutex_unlock(&tracing_cpumask_update_lock);
+
+       return count;
+}
+
+static ssize_t
+tracing_cpumask_write(struct file *filp, const char __user *ubuf,
+                     size_t count, loff_t *ppos)
+{
+       int err, cpu;
+
+       mutex_lock(&tracing_cpumask_update_lock);
+       err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
+       if (err)
+               goto err_unlock;
+
+       raw_local_irq_disable();
+       __raw_spin_lock(&ftrace_max_lock);
+       for_each_tracing_cpu(cpu) {
+               /*
+                * Increase/decrease the disabled counter if we are
+                * about to flip a bit in the cpumask:
+                */
+               if (cpu_isset(cpu, tracing_cpumask) &&
+                               !cpu_isset(cpu, tracing_cpumask_new)) {
+                       atomic_inc(&global_trace.data[cpu]->disabled);
+               }
+               if (!cpu_isset(cpu, tracing_cpumask) &&
+                               cpu_isset(cpu, tracing_cpumask_new)) {
+                       atomic_dec(&global_trace.data[cpu]->disabled);
+               }
+       }
+       __raw_spin_unlock(&ftrace_max_lock);
+       raw_local_irq_enable();
+
+       tracing_cpumask = tracing_cpumask_new;
+
+       mutex_unlock(&tracing_cpumask_update_lock);
+
+       return count;
+
+err_unlock:
+       mutex_unlock(&tracing_cpumask_update_lock);
+
+       return err;
+}
+
+static struct file_operations tracing_cpumask_fops = {
+       .open           = tracing_open_generic,
+       .read           = tracing_cpumask_read,
+       .write          = tracing_cpumask_write,
 };
 
 static ssize_t
@@ -1526,8 +2188,7 @@ tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
        r += sprintf(buf + r, "\n");
        WARN_ON(r >= len + 2);
 
-       r = simple_read_from_buffer(ubuf, cnt, ppos,
-                                   buf, r);
+       r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 
        kfree(buf);
 
@@ -1543,8 +2204,8 @@ tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
        int neg = 0;
        int i;
 
-       if (cnt > 63)
-               cnt = 63;
+       if (cnt >= sizeof(buf))
+               return -EINVAL;
 
        if (copy_from_user(&buf, ubuf, cnt))
                return -EFAULT;
@@ -1567,6 +2228,11 @@ 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;
 
        filp->f_pos += cnt;
 
@@ -1574,9 +2240,9 @@ 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,
+       .open           = tracing_open_generic,
+       .read           = tracing_iter_ctrl_read,
+       .write          = tracing_iter_ctrl_write,
 };
 
 static const char readme_msg[] =
@@ -1607,11 +2273,10 @@ tracing_readme_read(struct file *filp, char __user *ubuf,
 }
 
 static struct file_operations tracing_readme_fops = {
-       .open = tracing_open_generic,
-       .read = tracing_readme_read,
+       .open           = tracing_open_generic,
+       .read           = tracing_readme_read,
 };
 
-
 static ssize_t
 tracing_ctrl_read(struct file *filp, char __user *ubuf,
                  size_t cnt, loff_t *ppos)
@@ -1629,18 +2294,21 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf,
                   size_t cnt, loff_t *ppos)
 {
        struct trace_array *tr = filp->private_data;
-       long val;
        char buf[64];
+       long val;
+       int ret;
 
-       if (cnt > 63)
-               cnt = 63;
+       if (cnt >= sizeof(buf))
+               return -EINVAL;
 
        if (copy_from_user(&buf, ubuf, cnt))
                return -EFAULT;
 
        buf[cnt] = 0;
 
-       val = simple_strtoul(buf, NULL, 10);
+       ret = strict_strtoul(buf, 10, &val);
+       if (ret < 0)
+               return ret;
 
        val = !!val;
 
@@ -1732,10 +2400,10 @@ tracing_max_lat_read(struct file *filp, char __user *ubuf,
        char buf[64];
        int r;
 
-       r = snprintf(buf, 64, "%ld\n",
+       r = snprintf(buf, sizeof(buf), "%ld\n",
                     *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
-       if (r > 64)
-               r = 64;
+       if (r > sizeof(buf))
+               r = sizeof(buf);
        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
@@ -1744,18 +2412,21 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf,
                      size_t cnt, loff_t *ppos)
 {
        long *ptr = filp->private_data;
-       long val;
        char buf[64];
+       long val;
+       int ret;
 
-       if (cnt > 63)
-               cnt = 63;
+       if (cnt >= sizeof(buf))
+               return -EINVAL;
 
        if (copy_from_user(&buf, ubuf, cnt))
                return -EFAULT;
 
        buf[cnt] = 0;
 
-       val = simple_strtoul(buf, NULL, 10);
+       ret = strict_strtoul(buf, 10, &val);
+       if (ret < 0)
+               return ret;
 
        *ptr = val * 1000;
 
@@ -1782,10 +2453,15 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
        if (!iter)
                return -ENOMEM;
 
+       mutex_lock(&trace_types_lock);
        iter->tr = &global_trace;
-
+       iter->trace = current_trace;
        filp->private_data = iter;
 
+       if (iter->trace->pipe_open)
+               iter->trace->pipe_open(iter);
+       mutex_unlock(&trace_types_lock);
+
        return 0;
 }
 
@@ -1799,6 +2475,27 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
        return 0;
 }
 
+static unsigned int
+tracing_poll_pipe(struct file *filp, poll_table *poll_table)
+{
+       struct trace_iterator *iter = filp->private_data;
+
+       if (trace_flags & TRACE_ITER_BLOCK) {
+               /*
+                * Always select as readable when in blocking mode
+                */
+               return POLLIN | POLLRDNORM;
+       } else {
+               if (!trace_empty(iter))
+                       return POLLIN | POLLRDNORM;
+               poll_wait(filp, &trace_wait, poll_table);
+               if (!trace_empty(iter))
+                       return POLLIN | POLLRDNORM;
+
+               return 0;
+       }
+}
+
 /*
  * Consumer reader.
  */
@@ -1809,32 +2506,35 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
        struct trace_iterator *iter = filp->private_data;
        struct trace_array_cpu *data;
        static cpumask_t mask;
-       struct trace_entry *entry;
-       static int start;
        unsigned long flags;
-       int read = 0;
+#ifdef CONFIG_FTRACE
+       int ftrace_save;
+#endif
        int cpu;
-       int len;
-       int ret;
+       ssize_t sret;
 
        /* return any leftover data */
-       if (iter->seq.len > start) {
-               len = iter->seq.len - start;
-               if (cnt > len)
-                       cnt = len;
-               ret = copy_to_user(ubuf, iter->seq.buffer + start, cnt);
-               if (ret)
-                       cnt = -EFAULT;
+       sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
+       if (sret != -EBUSY)
+               return sret;
+       sret = 0;
 
-               start += len;
+       trace_seq_reset(&iter->seq);
 
-               return cnt;
+       mutex_lock(&trace_types_lock);
+       if (iter->trace->read) {
+               sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
+               if (sret)
+                       goto out;
        }
 
-       trace_seq_reset(&iter->seq);
-       start = 0;
-
        while (trace_empty(iter)) {
+
+               if ((filp->f_flags & O_NONBLOCK)) {
+                       sret = -EAGAIN;
+                       goto out;
+               }
+
                /*
                 * This is a make-shift waitqueue. The reason we don't use
                 * an actual wait queue is because:
@@ -1847,13 +2547,22 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
                set_current_state(TASK_INTERRUPTIBLE);
                iter->tr->waiter = current;
 
-               /* sleep for one second, and try again. */
-               schedule_timeout(HZ);
+               mutex_unlock(&trace_types_lock);
+
+               /* sleep for 100 msecs, and try again. */
+               schedule_timeout(HZ/10);
+
+               mutex_lock(&trace_types_lock);
 
                iter->tr->waiter = NULL;
 
-               if (signal_pending(current))
-                       return -EINTR;
+               if (signal_pending(current)) {
+                       sret = -EINTR;
+                       goto out;
+               }
+
+               if (iter->trace != current_trace)
+                       goto out;
 
                /*
                 * We block until we read something and tracing is disabled.
@@ -1872,13 +2581,15 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 
        /* stop when tracing is finished */
        if (trace_empty(iter))
-               return 0;
+               goto out;
 
        if (cnt >= PAGE_SIZE)
                cnt = PAGE_SIZE - 1;
 
-       memset(iter, 0, sizeof(*iter));
-       iter->tr = &global_trace;
+       /* reset all but tr, trace, and overruns */
+       memset(&iter->seq, 0,
+              sizeof(struct trace_iterator) -
+              offsetof(struct trace_iterator, seq));
        iter->pos = -1;
 
        /*
@@ -1890,59 +2601,176 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 
        cpus_clear(mask);
        local_irq_save(flags);
-       for_each_possible_cpu(cpu) {
+#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);
-               spin_lock(&data->lock);
                cpu_set(cpu, mask);
        }
 
-       while ((entry = find_next_entry(iter, &cpu))) {
+       for_each_cpu_mask(cpu, mask) {
+               data = iter->tr->data[cpu];
+               __raw_spin_lock(&data->lock);
 
-               if (!entry)
-                       break;
+               if (data->overrun > iter->last_overrun[cpu])
+                       iter->overrun[cpu] +=
+                               data->overrun - iter->last_overrun[cpu];
+               iter->last_overrun[cpu] = data->overrun;
+       }
 
-               iter->ent = entry;
-               iter->cpu = cpu;
+       while (find_next_entry_inc(iter) != NULL) {
+               int ret;
+               int len = iter->seq.len;
 
-               ret = print_trace_fmt(iter);
-               if (!ret)
+               ret = print_trace_line(iter);
+               if (!ret) {
+                       /* don't print partial lines */
+                       iter->seq.len = len;
                        break;
+               }
 
                trace_consume(iter);
 
                if (iter->seq.len >= cnt)
                        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];
-               spin_unlock(&data->lock);
                atomic_dec(&data->disabled);
        }
+#ifdef CONFIG_FTRACE
+       ftrace_enabled = ftrace_save;
+#endif
        local_irq_restore(flags);
 
        /* Now copy what we have to the user */
-       read = iter->seq.len;
-       if (read > cnt)
-               read = cnt;
+       sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
+       if (iter->seq.readpos >= iter->seq.len)
+               trace_seq_reset(&iter->seq);
+       if (sret == -EBUSY)
+               sret = 0;
 
-       ret = copy_to_user(ubuf, iter->seq.buffer, read);
+out:
+       mutex_unlock(&trace_types_lock);
 
-       if (read < iter->seq.len)
-               start = read;
-       else
-               trace_seq_reset(&iter->seq);
+       return sret;
+}
 
-       if (ret)
-               read = -EFAULT;
+static ssize_t
+tracing_entries_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, "%lu\n", tr->entries);
+       return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+tracing_entries_write(struct file *filp, const char __user *ubuf,
+                     size_t cnt, loff_t *ppos)
+{
+       unsigned long val;
+       char buf[64];
+       int i, ret;
+
+       if (cnt >= sizeof(buf))
+               return -EINVAL;
+
+       if (copy_from_user(&buf, ubuf, cnt))
+               return -EFAULT;
+
+       buf[cnt] = 0;
+
+       ret = strict_strtoul(buf, 10, &val);
+       if (ret < 0)
+               return ret;
+
+       /* must have at least 1 entry */
+       if (!val)
+               return -EINVAL;
+
+       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;
+
+               /* account for each buffer (and max_tr) */
+               pages_requested *= tracing_nr_buffers * 2;
+
+               /* Check for overflow */
+               if (pages_requested < 0) {
+                       cnt = -ENOMEM;
+                       goto out;
+               }
+
+               freeable_pages = determine_dirtyable_memory();
+
+               /* we only allow to request 1/4 of useable memory */
+               if (pages_requested >
+                   ((freeable_pages + tracing_pages_allocated) / 4)) {
+                       cnt = -ENOMEM;
+                       goto out;
+               }
+
+               while (global_trace.entries < val) {
+                       if (trace_alloc_page()) {
+                               cnt = -ENOMEM;
+                               goto out;
+                       }
+                       /* double check that we don't go over the known pages */
+                       if (tracing_pages_allocated > pages_requested)
+                               break;
+               }
+
+       } else {
+               /* include the number of entries in val (inc of page entries) */
+               while (global_trace.entries > val + (ENTRIES_PER_PAGE - 1))
+                       trace_free_page();
+       }
+
+       /* check integrity */
+       for_each_tracing_cpu(i)
+               check_pages(global_trace.data[i]);
+
+       filp->f_pos += cnt;
+
+       /* If check pages failed, return ENOMEM */
+       if (tracing_disabled)
+               cnt = -ENOMEM;
+ out:
+       max_tr.entries = global_trace.entries;
+       mutex_unlock(&trace_types_lock);
 
-       return read;
+       return cnt;
 }
 
 static struct file_operations tracing_max_lat_fops = {
@@ -1965,10 +2793,17 @@ static struct file_operations set_tracer_fops = {
 
 static struct file_operations tracing_pipe_fops = {
        .open           = tracing_open_pipe,
+       .poll           = tracing_poll_pipe,
        .read           = tracing_read_pipe,
        .release        = tracing_release_pipe,
 };
 
+static struct file_operations tracing_entries_fops = {
+       .open           = tracing_open_generic,
+       .read           = tracing_entries_read,
+       .write          = tracing_entries_write,
+};
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 
 static ssize_t
@@ -2032,6 +2867,11 @@ static __init void tracer_init_debugfs(void)
        if (!entry)
                pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
 
+       entry = debugfs_create_file("tracing_cpumask", 0644, d_tracer,
+                                   NULL, &tracing_cpumask_fops);
+       if (!entry)
+               pr_warning("Could not create debugfs 'tracing_cpumask' entry\n");
+
        entry = debugfs_create_file("latency_trace", 0444, d_tracer,
                                    &global_trace, &tracing_lt_fops);
        if (!entry)
@@ -2075,6 +2915,12 @@ static __init void tracer_init_debugfs(void)
                pr_warning("Could not create debugfs "
                           "'tracing_threash' entry\n");
 
+       entry = debugfs_create_file("trace_entries", 0644, d_tracer,
+                                   &global_trace, &tracing_entries_fops);
+       if (!entry)
+               pr_warning("Could not create debugfs "
+                          "'tracing_threash' entry\n");
+
 #ifdef CONFIG_DYNAMIC_FTRACE
        entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
                                    &ftrace_update_tot_cnt,
@@ -2083,24 +2929,22 @@ static __init void tracer_init_debugfs(void)
                pr_warning("Could not create debugfs "
                           "'dyn_ftrace_total_info' entry\n");
 #endif
+#ifdef CONFIG_SYSPROF_TRACER
+       init_tracer_sysprof_debugfs(d_tracer);
+#endif
 }
 
-/* dummy trace to disable tracing */
-static struct tracer no_tracer __read_mostly =
-{
-       .name           = "none",
-};
-
 static int trace_alloc_page(void)
 {
        struct trace_array_cpu *data;
        struct page *page, *tmp;
        LIST_HEAD(pages);
        void *array;
+       unsigned pages_allocated = 0;
        int i;
 
        /* first allocate a page for each CPU */
-       for_each_possible_cpu(i) {
+       for_each_tracing_cpu(i) {
                array = (void *)__get_free_page(GFP_KERNEL);
                if (array == NULL) {
                        printk(KERN_ERR "tracer: failed to allocate page"
@@ -2108,6 +2952,7 @@ static int trace_alloc_page(void)
                        goto free_pages;
                }
 
+               pages_allocated++;
                page = virt_to_page(array);
                list_add(&page->lru, &pages);
 
@@ -2119,16 +2964,15 @@ static int trace_alloc_page(void)
                               "for trace buffer!\n");
                        goto free_pages;
                }
+               pages_allocated++;
                page = virt_to_page(array);
                list_add(&page->lru, &pages);
 #endif
        }
 
        /* Now that we successfully allocate a page per CPU, add them */
-       for_each_possible_cpu(i) {
+       for_each_tracing_cpu(i) {
                data = global_trace.data[i];
-               spin_lock_init(&data->lock);
-               lockdep_set_class(&data->lock, &data->lock_key);
                page = list_entry(pages.next, struct page, lru);
                list_del_init(&page->lru);
                list_add_tail(&page->lru, &data->trace_pages);
@@ -2136,14 +2980,13 @@ static int trace_alloc_page(void)
 
 #ifdef CONFIG_TRACER_MAX_TRACE
                data = max_tr.data[i];
-               spin_lock_init(&data->lock);
-               lockdep_set_class(&data->lock, &data->lock_key);
                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;
 
        return 0;
@@ -2156,6 +2999,57 @@ static int trace_alloc_page(void)
        return -ENOMEM;
 }
 
+static int trace_free_page(void)
+{
+       struct trace_array_cpu *data;
+       struct page *page;
+       struct list_head *p;
+       int i;
+       int ret = 0;
+
+       /* 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);
+
+               tracing_reset(data);
+
+#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);
+
+               tracing_reset(data);
+#endif
+       }
+       global_trace.entries -= ENTRIES_PER_PAGE;
+
+       return ret;
+}
+
 __init static int tracer_alloc_buffers(void)
 {
        struct trace_array_cpu *data;
@@ -2165,8 +3059,12 @@ __init static int tracer_alloc_buffers(void)
        int ret = -ENOMEM;
        int i;
 
+       /* TODO: make the number of buffers hot pluggable with CPUS */
+       tracing_nr_buffers = num_possible_cpus();
+       tracing_buffer_mask = cpu_possible_map;
+
        /* Allocate the first page for all buffers */
-       for_each_possible_cpu(i) {
+       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);
 
@@ -2184,6 +3082,9 @@ __init static int tracer_alloc_buffers(void)
                /* use the LRU flag to differentiate the two buffers */
                ClearPageLRU(page);
 
+               data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+               max_tr.data[i]->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+
 /* Only allocate if we are actually using the max trace */
 #ifdef CONFIG_TRACER_MAX_TRACE
                array = (void *)__get_free_page(GFP_KERNEL);
@@ -2214,9 +3115,8 @@ __init static int tracer_alloc_buffers(void)
        }
        max_tr.entries = global_trace.entries;
 
-       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("tracer: %d pages allocated for %ld entries of %ld bytes\n",
+               pages, trace_nr_entries, (long)TRACE_ENTRY_SIZE);
        pr_info("   actual entries %ld\n", global_trace.entries);
 
        tracer_init_debugfs();
@@ -2227,6 +3127,7 @@ __init static int tracer_alloc_buffers(void)
        current_trace = &no_tracer;
 
        /* All seems OK, enable tracing */
+       global_trace.ctrl = tracer_enabled;
        tracing_disabled = 0;
 
        return 0;