1 files changed, 307 insertions, 207 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b20d3ec75de9..44f916a04065 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -12,7 +12,7 @@
  *  Copyright (C) 2004 William Lee Irwin III
  */
 #include <linux/ring_buffer.h>
-#include <linux/utsrelease.h>
+#include <generated/utsrelease.h>
 #include <linux/stacktrace.h>
 #include <linux/writeback.h>
 #include <linux/kallsyms.h>
@@ -32,10 +32,11 @@
 #include <linux/splice.h>
 #include <linux/kdebug.h>
 #include <linux/string.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
 #include <linux/ctype.h>
 #include <linux/init.h>
 #include <linux/poll.h>
-#include <linux/gfp.h>
 #include <linux/fs.h>
 
 #include "trace.h"
@@ -86,25 +87,22 @@ static int dummy_set_flag(u32 old_flags, u32 bit, int set)
  */
 static int tracing_disabled = 1;
 
-DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
+DEFINE_PER_CPU(int, ftrace_cpu_disabled);
 
 static inline void ftrace_disable_cpu(void)
 {
         preempt_disable();
-        local_inc(&__get_cpu_var(ftrace_cpu_disabled));
+        __this_cpu_inc(ftrace_cpu_disabled);
 }
 
 static inline void ftrace_enable_cpu(void)
 {
-        local_dec(&__get_cpu_var(ftrace_cpu_disabled));
+        __this_cpu_dec(ftrace_cpu_disabled);
         preempt_enable();
 }
 
 static cpumask_var_t __read_mostly      tracing_buffer_mask;
 
-/* Define which cpu buffers are currently read in trace_pipe */
-static cpumask_var_t                    tracing_reader_cpumask;
-
 #define for_each_tracing_cpu(cpu)       \
         for_each_cpu(cpu, tracing_buffer_mask)
 
@@ -129,7 +127,7 @@ static int tracing_set_tracer(const char *buf);
 static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
 static char *default_bootup_tracer;
 
-static int __init set_ftrace(char *str)
+static int __init set_cmdline_ftrace(char *str)
 {
         strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
         default_bootup_tracer = bootup_tracer_buf;
@@ -137,7 +135,7 @@ static int __init set_ftrace(char *str)
         ring_buffer_expanded = 1;
         return 1;
 }
-__setup("ftrace=", set_ftrace);
+__setup("ftrace=", set_cmdline_ftrace);
 
 static int __init set_ftrace_dump_on_oops(char *str)
 {
@@ -203,7 +201,7 @@ cycle_t ftrace_now(int cpu)
  */
 static struct trace_array       max_tr;
 
-static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
+static DEFINE_PER_CPU(struct trace_array_cpu, max_tr_data);
 
 /* tracer_enabled is used to toggle activation of a tracer */
 static int                      tracer_enabled = 1;
@@ -243,12 +241,91 @@ static struct tracer		*current_trace __read_mostly;
 
 /*
  * 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);
 
+/*
+ * serialize the access of the ring buffer
+ *
+ * ring buffer serializes readers, but it is low level protection.
+ * The validity of the events (which returns by ring_buffer_peek() ..etc)
+ * are not protected by ring buffer.
+ *
+ * The content of events may become garbage if we allow other process consumes
+ * these events concurrently:
+ *   A) the page of the consumed events may become a normal page
+ *      (not reader page) in ring buffer, and this page will be rewrited
+ *      by events producer.
+ *   B) The page of the consumed events may become a page for splice_read,
+ *      and this page will be returned to system.
+ *
+ * These primitives allow multi process access to different cpu ring buffer
+ * concurrently.
+ *
+ * These primitives don't distinguish read-only and read-consume access.
+ * Multi read-only access are also serialized.
+ */
+
+#ifdef CONFIG_SMP
+static DECLARE_RWSEM(all_cpu_access_lock);
+static DEFINE_PER_CPU(struct mutex, cpu_access_lock);
+
+static inline void trace_access_lock(int cpu)
+{
+        if (cpu == TRACE_PIPE_ALL_CPU) {
+                /* gain it for accessing the whole ring buffer. */
+                down_write(&all_cpu_access_lock);
+        } else {
+                /* gain it for accessing a cpu ring buffer. */
+
+                /* Firstly block other trace_access_lock(TRACE_PIPE_ALL_CPU). */
+                down_read(&all_cpu_access_lock);
+
+                /* Secondly block other access to this @cpu ring buffer. */
+                mutex_lock(&per_cpu(cpu_access_lock, cpu));
+        }
+}
+
+static inline void trace_access_unlock(int cpu)
+{
+        if (cpu == TRACE_PIPE_ALL_CPU) {
+                up_write(&all_cpu_access_lock);
+        } else {
+                mutex_unlock(&per_cpu(cpu_access_lock, cpu));
+                up_read(&all_cpu_access_lock);
+        }
+}
+
+static inline void trace_access_lock_init(void)
+{
+        int cpu;
+
+        for_each_possible_cpu(cpu)
+                mutex_init(&per_cpu(cpu_access_lock, cpu));
+}
+
+#else
+
+static DEFINE_MUTEX(access_lock);
+
+static inline void trace_access_lock(int cpu)
+{
+        (void)cpu;
+        mutex_lock(&access_lock);
+}
+
+static inline void trace_access_unlock(int cpu)
+{
+        (void)cpu;
+        mutex_unlock(&access_lock);
+}
+
+static inline void trace_access_lock_init(void)
+{
+}
+
+#endif
+
 /* trace_wait is a waitqueue for tasks blocked on trace_poll */
 static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
 
@@ -297,6 +374,21 @@ static int __init set_buf_size(char *str)
 }
 __setup("trace_buf_size=", set_buf_size);
 
+static int __init set_tracing_thresh(char *str)
+{
+        unsigned long threshhold;
+        int ret;
+
+        if (!str)
+                return 0;
+        ret = strict_strtoul(str, 0, &threshhold);
+        if (ret < 0)
+                return 0;
+        tracing_thresh = threshhold * 1000;
+        return 1;
+}
+__setup("tracing_thresh=", set_tracing_thresh);
+
 unsigned long nsecs_to_usecs(unsigned long nsecs)
 {
         return nsecs / 1000;
@@ -313,7 +405,6 @@ static const char *trace_options[] = {
         "bin",
         "block",
         "stacktrace",
-        "sched-tree",
         "trace_printk",
         "ftrace_preempt",
         "branch",
@@ -493,19 +584,20 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
  * 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
+ * This is defined as a arch_spinlock_t in order to help
  * with performance when lockdep debugging is enabled.
  *
  * It is also used in other places outside the update_max_tr
  * so it needs to be defined outside of the
  * CONFIG_TRACER_MAX_TRACE.
  */
-static raw_spinlock_t ftrace_max_lock =
-        (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+static arch_spinlock_t ftrace_max_lock =
+        (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
+
+unsigned long __read_mostly     tracing_thresh;
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 unsigned long __read_mostly     tracing_max_latency;
-unsigned long __read_mostly     tracing_thresh;
 
 /*
  * Copy the new maximum trace into the separate maximum-trace
@@ -516,7 +608,7 @@ static void
 __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
         struct trace_array_cpu *data = tr->data[cpu];
-        struct trace_array_cpu *max_data = tr->data[cpu];
+        struct trace_array_cpu *max_data;
 
         max_tr.cpu = cpu;
         max_tr.time_start = data->preempt_timestamp;
@@ -526,7 +618,7 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
         max_data->critical_start = data->critical_start;
         max_data->critical_end = data->critical_end;
 
-        memcpy(data->comm, tsk->comm, TASK_COMM_LEN);
+        memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
         max_data->pid = tsk->pid;
         max_data->uid = task_uid(tsk);
         max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
@@ -555,13 +647,13 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
                 return;
 
         WARN_ON_ONCE(!irqs_disabled());
-        __raw_spin_lock(&ftrace_max_lock);
+        arch_spin_lock(&ftrace_max_lock);
 
         tr->buffer = max_tr.buffer;
         max_tr.buffer = buf;
 
         __update_max_tr(tr, tsk, cpu);
-        __raw_spin_unlock(&ftrace_max_lock);
+        arch_spin_unlock(&ftrace_max_lock);
 }
 
 /**
@@ -581,7 +673,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
                 return;
 
         WARN_ON_ONCE(!irqs_disabled());
-        __raw_spin_lock(&ftrace_max_lock);
+        arch_spin_lock(&ftrace_max_lock);
 
         ftrace_disable_cpu();
 
@@ -603,7 +695,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
         WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY);
 
         __update_max_tr(tr, tsk, cpu);
-        __raw_spin_unlock(&ftrace_max_lock);
+        arch_spin_unlock(&ftrace_max_lock);
 }
 #endif /* CONFIG_TRACER_MAX_TRACE */
 
@@ -748,10 +840,10 @@ out:
         mutex_unlock(&trace_types_lock);
 }
 
-static void __tracing_reset(struct trace_array *tr, int cpu)
+static void __tracing_reset(struct ring_buffer *buffer, int cpu)
 {
         ftrace_disable_cpu();
-        ring_buffer_reset_cpu(tr->buffer, cpu);
+        ring_buffer_reset_cpu(buffer, cpu);
         ftrace_enable_cpu();
 }
 
@@ -763,7 +855,7 @@ void tracing_reset(struct trace_array *tr, int cpu)
 
         /* Make sure all commits have finished */
         synchronize_sched();
-        __tracing_reset(tr, cpu);
+        __tracing_reset(buffer, cpu);
 
         ring_buffer_record_enable(buffer);
 }
@@ -781,7 +873,7 @@ void tracing_reset_online_cpus(struct trace_array *tr)
         tr->time_start = ftrace_now(tr->cpu);
 
         for_each_online_cpu(cpu)
-                __tracing_reset(tr, cpu);
+                __tracing_reset(buffer, cpu);
 
         ring_buffer_record_enable(buffer);
 }
@@ -802,7 +894,7 @@ 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 raw_spinlock_t trace_cmdline_lock = __RAW_SPIN_LOCK_UNLOCKED;
+static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
 
 /* temporary disable recording */
 static atomic_t trace_record_cmdline_disabled __read_mostly;
@@ -858,6 +950,8 @@ void tracing_start(void)
                 goto out;
         }
 
+        /* Prevent the buffers from switching */
+        arch_spin_lock(&ftrace_max_lock);
 
         buffer = global_trace.buffer;
         if (buffer)
@@ -867,6 +961,8 @@ void tracing_start(void)
         if (buffer)
                 ring_buffer_record_enable(buffer);
 
+        arch_spin_unlock(&ftrace_max_lock);
+
         ftrace_start();
  out:
         spin_unlock_irqrestore(&tracing_start_lock, flags);
@@ -888,6 +984,9 @@ void tracing_stop(void)
         if (trace_stop_count++)
                 goto out;
 
+        /* Prevent the buffers from switching */
+        arch_spin_lock(&ftrace_max_lock);
+
         buffer = global_trace.buffer;
         if (buffer)
                 ring_buffer_record_disable(buffer);
@@ -896,6 +995,8 @@ void tracing_stop(void)
         if (buffer)
                 ring_buffer_record_disable(buffer);
 
+        arch_spin_unlock(&ftrace_max_lock);
+
  out:
         spin_unlock_irqrestore(&tracing_start_lock, flags);
 }
@@ -915,7 +1016,7 @@ static void trace_save_cmdline(struct task_struct *tsk)
          * nor do we want to disable interrupts,
          * so if we miss here, then better luck next time.
          */
-        if (!__raw_spin_trylock(&trace_cmdline_lock))
+        if (!arch_spin_trylock(&trace_cmdline_lock))
                 return;
 
         idx = map_pid_to_cmdline[tsk->pid];
@@ -940,7 +1041,7 @@ static void trace_save_cmdline(struct task_struct *tsk)
 
         memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
 
-        __raw_spin_unlock(&trace_cmdline_lock);
+        arch_spin_unlock(&trace_cmdline_lock);
 }
 
 void trace_find_cmdline(int pid, char comm[])
@@ -952,20 +1053,25 @@ void trace_find_cmdline(int pid, char comm[])
                 return;
         }
 
+        if (WARN_ON_ONCE(pid < 0)) {
+                strcpy(comm, "<XXX>");
+                return;
+        }
+
         if (pid > PID_MAX_DEFAULT) {
                 strcpy(comm, "<...>");
                 return;
         }
 
         preempt_disable();
-        __raw_spin_lock(&trace_cmdline_lock);
+        arch_spin_lock(&trace_cmdline_lock);
         map = map_pid_to_cmdline[pid];
         if (map != NO_CMDLINE_MAP)
                 strcpy(comm, saved_cmdlines[map]);
         else
                 strcpy(comm, "<...>");
 
-        __raw_spin_unlock(&trace_cmdline_lock);
+        arch_spin_unlock(&trace_cmdline_lock);
         preempt_enable();
 }
 
@@ -1085,7 +1191,7 @@ trace_function(struct trace_array *tr,
         struct ftrace_entry *entry;
 
         /* If we are reading the ring buffer, don't trace */
-        if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+        if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
                 return;
 
         event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
@@ -1151,6 +1257,22 @@ void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
         __ftrace_trace_stack(tr->buffer, flags, skip, pc);
 }
 
+/**
+ * trace_dump_stack - record a stack back trace in the trace buffer
+ */
+void trace_dump_stack(void)
+{
+        unsigned long flags;
+
+        if (tracing_disabled || tracing_selftest_running)
+                return;
+
+        local_save_flags(flags);
+
+        /* skipping 3 traces, seems to get us at the caller of this function */
+        __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count());
+}
+
 void
 ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
 {
@@ -1162,6 +1284,13 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
         if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
                 return;
 
+        /*
+         * NMIs can not handle page faults, even with fix ups.
+         * The save user stack can (and often does) fault.
+         */
+        if (unlikely(in_nmi()))
+                return;
+
         event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
                                           sizeof(*entry), flags, pc);
         if (!event)
@@ -1251,8 +1380,8 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
  */
 int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
 {
-        static raw_spinlock_t trace_buf_lock =
-                (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+        static arch_spinlock_t trace_buf_lock =
+                (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
         static u32 trace_buf[TRACE_BUF_SIZE];
 
         struct ftrace_event_call *call = &event_bprint;
@@ -1283,7 +1412,7 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
 
         /* Lockdep uses trace_printk for lock tracing */
         local_irq_save(flags);
-        __raw_spin_lock(&trace_buf_lock);
+        arch_spin_lock(&trace_buf_lock);
         len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
         if (len > TRACE_BUF_SIZE || len < 0)
@@ -1300,11 +1429,13 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
         entry->fmt                      = fmt;
 
         memcpy(entry->buf, trace_buf, sizeof(u32) * len);
-        if (!filter_check_discard(call, entry, buffer, event))
+        if (!filter_check_discard(call, entry, buffer, event)) {
                 ring_buffer_unlock_commit(buffer, event);
+                ftrace_trace_stack(buffer, flags, 6, pc);
+        }
 
 out_unlock:
-        __raw_spin_unlock(&trace_buf_lock);
+        arch_spin_unlock(&trace_buf_lock);
         local_irq_restore(flags);
 
 out:
@@ -1334,7 +1465,7 @@ int trace_array_printk(struct trace_array *tr,
 int trace_array_vprintk(struct trace_array *tr,
                         unsigned long ip, const char *fmt, va_list args)
 {
-        static raw_spinlock_t trace_buf_lock = __RAW_SPIN_LOCK_UNLOCKED;
+        static arch_spinlock_t trace_buf_lock = __ARCH_SPIN_LOCK_UNLOCKED;
         static char trace_buf[TRACE_BUF_SIZE];
 
         struct ftrace_event_call *call = &event_print;
@@ -1360,12 +1491,9 @@ int trace_array_vprintk(struct trace_array *tr,
 
         pause_graph_tracing();
         raw_local_irq_save(irq_flags);
-        __raw_spin_lock(&trace_buf_lock);
+        arch_spin_lock(&trace_buf_lock);
         len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
-        len = min(len, TRACE_BUF_SIZE-1);
-        trace_buf[len] = 0;
-
         size = sizeof(*entry) + len + 1;
         buffer = tr->buffer;
         event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
@@ -1373,15 +1501,17 @@ int trace_array_vprintk(struct trace_array *tr,
         if (!event)
                 goto out_unlock;
         entry = ring_buffer_event_data(event);
-        entry->ip                       = ip;
+        entry->ip = ip;
 
         memcpy(&entry->buf, trace_buf, len);
-        entry->buf[len] = 0;
-        if (!filter_check_discard(call, entry, buffer, event))
+        entry->buf[len] = '\0';
+        if (!filter_check_discard(call, entry, buffer, event)) {
                 ring_buffer_unlock_commit(buffer, event);
+                ftrace_trace_stack(buffer, irq_flags, 6, pc);
+        }
 
  out_unlock:
-        __raw_spin_unlock(&trace_buf_lock);
+        arch_spin_unlock(&trace_buf_lock);
         raw_local_irq_restore(irq_flags);
         unpause_graph_tracing();
  out:
@@ -1515,6 +1645,8 @@ static void *s_next(struct seq_file *m, void *v, loff_t *pos)
         int i = (int)*pos;
         void *ent;
 
+        WARN_ON_ONCE(iter->leftover);
+
         (*pos)++;
 
         /* can't go backwards */
@@ -1566,12 +1698,6 @@ static void tracing_iter_reset(struct trace_iterator *iter, int cpu)
 }
 
 /*
- * No necessary locking here. The worst thing which can
- * happen is loosing events consumed at the same time
- * by a trace_pipe reader.
- * Other than that, we don't risk to crash the ring buffer
- * because it serializes the readers.
- *
  * The current tracer is copied to avoid a global locking
  * all around.
  */
@@ -1609,21 +1735,34 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 
                 ftrace_enable_cpu();
 
+                iter->leftover = 0;
                 for (p = iter; p && l < *pos; p = s_next(m, p, &l))
                         ;
 
         } else {
-                l = *pos - 1;
-                p = s_next(m, p, &l);
+                /*
+                 * If we overflowed the seq_file before, then we want
+                 * to just reuse the trace_seq buffer again.
+                 */
+                if (iter->leftover)
+                        p = iter;
+                else {
+                        l = *pos - 1;
+                        p = s_next(m, p, &l);
+                }
         }
 
         trace_event_read_lock();
+        trace_access_lock(cpu_file);
         return p;
 }
 
 static void s_stop(struct seq_file *m, void *p)
 {
+        struct trace_iterator *iter = m->private;
+
         atomic_dec(&trace_record_cmdline_disabled);
+        trace_access_unlock(iter->cpu_file);
         trace_event_read_unlock();
 }
 
@@ -1922,6 +2061,7 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
 static int s_show(struct seq_file *m, void *v)
 {
         struct trace_iterator *iter = v;
+        int ret;
 
         if (iter->ent == NULL) {
                 if (iter->tr) {
@@ -1941,9 +2081,27 @@ static int s_show(struct seq_file *m, void *v)
                         if (!(trace_flags & TRACE_ITER_VERBOSE))
                                 print_func_help_header(m);
                 }
+        } else if (iter->leftover) {
+                /*
+                 * If we filled the seq_file buffer earlier, we
+                 * want to just show it now.
+                 */
+                ret = trace_print_seq(m, &iter->seq);
+
+                /* ret should this time be zero, but you never know */
+                iter->leftover = ret;
+
         } else {
                 print_trace_line(iter);
-                trace_print_seq(m, &iter->seq);
+                ret = trace_print_seq(m, &iter->seq);
+                /*
+                 * If we overflow the seq_file buffer, then it will
+                 * ask us for this data again at start up.
+                 * Use that instead.
+                 *  ret is 0 if seq_file write succeeded.
+                 *        -1 otherwise.
+                 */
+                iter->leftover = ret;
         }
 
         return 0;
@@ -2253,7 +2411,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
         mutex_lock(&tracing_cpumask_update_lock);
 
         local_irq_disable();
-        __raw_spin_lock(&ftrace_max_lock);
+        arch_spin_lock(&ftrace_max_lock);
         for_each_tracing_cpu(cpu) {
                 /*
                  * Increase/decrease the disabled counter if we are
@@ -2268,7 +2426,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
                         atomic_dec(&global_trace.data[cpu]->disabled);
                 }
         }
-        __raw_spin_unlock(&ftrace_max_lock);
+        arch_spin_unlock(&ftrace_max_lock);
         local_irq_enable();
 
         cpumask_copy(tracing_cpumask, tracing_cpumask_new);
@@ -2290,67 +2448,49 @@ static const struct file_operations tracing_cpumask_fops = {
         .write          = tracing_cpumask_write,
 };
 
-static ssize_t
-tracing_trace_options_read(struct file *filp, char __user *ubuf,
-                       size_t cnt, loff_t *ppos)
+static int tracing_trace_options_show(struct seq_file *m, void *v)
 {
         struct tracer_opt *trace_opts;
         u32 tracer_flags;
-        int len = 0;
-        char *buf;
-        int r = 0;
         int i;
 
-
-        /* calculate max size */
-        for (i = 0; trace_options[i]; i++) {
-                len += strlen(trace_options[i]);
-                len += 3; /* "no" and newline */
-        }
-
         mutex_lock(&trace_types_lock);
         tracer_flags = current_trace->flags->val;
         trace_opts = current_trace->flags->opts;
 
-        /*
-         * 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 newline */
-        }
-
-        /* +1 for \0 */
-        buf = kmalloc(len + 1, GFP_KERNEL);
-        if (!buf) {
-                mutex_unlock(&trace_types_lock);
-                return -ENOMEM;
-        }
-
         for (i = 0; trace_options[i]; i++) {
                 if (trace_flags & (1 << i))
-                        r += sprintf(buf + r, "%s\n", trace_options[i]);
+                        seq_printf(m, "%s\n", trace_options[i]);
                 else
-                        r += sprintf(buf + r, "no%s\n", trace_options[i]);
+                        seq_printf(m, "no%s\n", trace_options[i]);
         }
 
         for (i = 0; trace_opts[i].name; i++) {
                 if (tracer_flags & trace_opts[i].bit)
-                        r += sprintf(buf + r, "%s\n",
-                                trace_opts[i].name);
+                        seq_printf(m, "%s\n", trace_opts[i].name);
                 else
-                        r += sprintf(buf + r, "no%s\n",
-                                trace_opts[i].name);
+                        seq_printf(m, "no%s\n", trace_opts[i].name);
         }
         mutex_unlock(&trace_types_lock);
 
-        WARN_ON(r >= len + 1);
+        return 0;
+}
 
-        r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+static int __set_tracer_option(struct tracer *trace,
+                               struct tracer_flags *tracer_flags,
+                               struct tracer_opt *opts, int neg)
+{
+        int ret;
 
-        kfree(buf);
-        return r;
+        ret = trace->set_flag(tracer_flags->val, opts->bit, !neg);
+        if (ret)
+                return ret;
+
+        if (neg)
+                tracer_flags->val &= ~opts->bit;
+        else
+                tracer_flags->val |= opts->bit;
+        return 0;
 }
 
 /* Try to assign a tracer specific option */
@@ -2358,33 +2498,17 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
 {
         struct tracer_flags *tracer_flags = trace->flags;
         struct tracer_opt *opts = NULL;
-        int ret = 0, i = 0;
-        int len;
+        int i;
 
         for (i = 0; tracer_flags->opts[i].name; i++) {
                 opts = &tracer_flags->opts[i];
-                len = strlen(opts->name);
 
-                if (strncmp(cmp, opts->name, len) == 0) {
-                        ret = trace->set_flag(tracer_flags->val,
-                                opts->bit, !neg);
-                        break;
-                }
+                if (strcmp(cmp, opts->name) == 0)
+                        return __set_tracer_option(trace, trace->flags,
+                                                   opts, neg);
         }
-        /* Not found */
-        if (!tracer_flags->opts[i].name)
-                return -EINVAL;
-
-        /* Refused to handle */
-        if (ret)
-                return ret;
-
-        if (neg)
-                tracer_flags->val &= ~opts->bit;
-        else
-                tracer_flags->val |= opts->bit;
 
-        return 0;
+        return -EINVAL;
 }
 
 static void set_tracer_flags(unsigned int mask, int enabled)
@@ -2404,7 +2528,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
                         size_t cnt, loff_t *ppos)
 {
         char buf[64];
-        char *cmp = buf;
+        char *cmp;
         int neg = 0;
         int ret;
         int i;
@@ -2416,16 +2540,15 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
                 return -EFAULT;
 
         buf[cnt] = 0;
+        cmp = strstrip(buf);
 
-        if (strncmp(buf, "no", 2) == 0) {
+        if (strncmp(cmp, "no", 2) == 0) {
                 neg = 1;
                 cmp += 2;
         }
 
         for (i = 0; trace_options[i]; i++) {
-                int len = strlen(trace_options[i]);
-
-                if (strncmp(cmp, trace_options[i], len) == 0) {
+                if (strcmp(cmp, trace_options[i]) == 0) {
                         set_tracer_flags(1 << i, !neg);
                         break;
                 }
@@ -2445,9 +2568,18 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
         return cnt;
 }
 
+static int tracing_trace_options_open(struct inode *inode, struct file *file)
+{
+        if (tracing_disabled)
+                return -ENODEV;
+        return single_open(file, tracing_trace_options_show, NULL);
+}
+
 static const struct file_operations tracing_iter_fops = {
-        .open           = tracing_open_generic,
-        .read           = tracing_trace_options_read,
+        .open           = tracing_trace_options_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
         .write          = tracing_trace_options_write,
 };
 
@@ -2821,22 +2953,6 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
 
         mutex_lock(&trace_types_lock);
 
-        /* We only allow one reader per cpu */
-        if (cpu_file == TRACE_PIPE_ALL_CPU) {
-                if (!cpumask_empty(tracing_reader_cpumask)) {
-                        ret = -EBUSY;
-                        goto out;
-                }
-                cpumask_setall(tracing_reader_cpumask);
-        } else {
-                if (!cpumask_test_cpu(cpu_file, tracing_reader_cpumask))
-                        cpumask_set_cpu(cpu_file, tracing_reader_cpumask);
-                else {
-                        ret = -EBUSY;
-                        goto out;
-                }
-        }
-
         /* create a buffer to store the information to pass to userspace */
         iter = kzalloc(sizeof(*iter), GFP_KERNEL);
         if (!iter) {
@@ -2892,10 +3008,8 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
 
         mutex_lock(&trace_types_lock);
 
-        if (iter->cpu_file == TRACE_PIPE_ALL_CPU)
-                cpumask_clear(tracing_reader_cpumask);
-        else
-                cpumask_clear_cpu(iter->cpu_file, tracing_reader_cpumask);
+        if (iter->trace->pipe_close)
+                iter->trace->pipe_close(iter);
 
         mutex_unlock(&trace_types_lock);
 
@@ -3055,6 +3169,7 @@ waitagain:
         iter->pos = -1;
 
         trace_event_read_lock();
+        trace_access_lock(iter->cpu_file);
         while (find_next_entry_inc(iter) != NULL) {
                 enum print_line_t ret;
                 int len = iter->seq.len;
@@ -3071,6 +3186,7 @@ waitagain:
                 if (iter->seq.len >= cnt)
                         break;
         }
+        trace_access_unlock(iter->cpu_file);
         trace_event_read_unlock();
 
         /* Now copy what we have to the user */
@@ -3103,7 +3219,7 @@ static void tracing_spd_release_pipe(struct splice_pipe_desc *spd,
         __free_page(spd->pages[idx]);
 }
 
-static struct pipe_buf_operations tracing_pipe_buf_ops = {
+static const struct pipe_buf_operations tracing_pipe_buf_ops = {
         .can_merge              = 0,
         .map                    = generic_pipe_buf_map,
         .unmap                  = generic_pipe_buf_unmap,
@@ -3196,6 +3312,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
         }
 
         trace_event_read_lock();
+        trace_access_lock(iter->cpu_file);
 
         /* Fill as many pages as possible. */
         for (i = 0, rem = len; i < PIPE_BUFFERS && rem; i++) {
@@ -3219,6 +3336,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
                 trace_seq_init(&iter->seq);
         }
 
+        trace_access_unlock(iter->cpu_file);
         trace_event_read_unlock();
         mutex_unlock(&iter->mutex);
 
@@ -3334,7 +3452,6 @@ 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;
@@ -3342,7 +3459,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
         if (cnt > TRACE_BUF_SIZE)
                 cnt = TRACE_BUF_SIZE;
 
-        buf = kmalloc(cnt + 1, GFP_KERNEL);
+        buf = kmalloc(cnt + 2, GFP_KERNEL);
         if (buf == NULL)
                 return -ENOMEM;
 
@@ -3350,35 +3467,31 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
                 kfree(buf);
                 return -EFAULT;
         }
+        if (buf[cnt-1] != '\n') {
+                buf[cnt] = '\n';
+                buf[cnt+1] = '\0';
+        } else
+                buf[cnt] = '\0';
 
-        /* Cut from the first nil or newline. */
-        buf[cnt] = '\0';
-        end = strchr(buf, '\n');
-        if (end)
-                *end = '\0';
-
-        cnt = mark_printk("%s\n", buf);
+        cnt = mark_printk("%s", buf);
         kfree(buf);
         *fpos += cnt;
 
         return cnt;
 }
 
-static ssize_t tracing_clock_read(struct file *filp, char __user *ubuf,
-                                  size_t cnt, loff_t *ppos)
+static int tracing_clock_show(struct seq_file *m, void *v)
 {
-        char buf[64];
-        int bufiter = 0;
         int i;
 
         for (i = 0; i < ARRAY_SIZE(trace_clocks); i++)
-                bufiter += snprintf(buf + bufiter, sizeof(buf) - bufiter,
+                seq_printf(m,
                         "%s%s%s%s", i ? " " : "",
                         i == trace_clock_id ? "[" : "", trace_clocks[i].name,
                         i == trace_clock_id ? "]" : "");
-        bufiter += snprintf(buf + bufiter, sizeof(buf) - bufiter, "\n");
+        seq_putc(m, '\n');
 
-        return simple_read_from_buffer(ubuf, cnt, ppos, buf, bufiter);
+        return 0;
 }
 
 static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
@@ -3420,6 +3533,13 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
         return cnt;
 }
 
+static int tracing_clock_open(struct inode *inode, struct file *file)
+{
+        if (tracing_disabled)
+                return -ENODEV;
+        return single_open(file, tracing_clock_show, NULL);
+}
+
 static const struct file_operations tracing_max_lat_fops = {
         .open           = tracing_open_generic,
         .read           = tracing_max_lat_read,
@@ -3458,8 +3578,10 @@ static const struct file_operations tracing_mark_fops = {
 };
 
 static const struct file_operations trace_clock_fops = {
-        .open           = tracing_open_generic,
-        .read           = tracing_clock_read,
+        .open           = tracing_clock_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
         .write          = tracing_clock_write,
 };
 
@@ -3516,10 +3638,12 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 
         info->read = 0;
 
+        trace_access_lock(info->cpu);
         ret = ring_buffer_read_page(info->tr->buffer,
                                     &info->spare,
                                     count,
                                     info->cpu, 0);
+        trace_access_unlock(info->cpu);
         if (ret < 0)
                 return 0;
 
@@ -3589,7 +3713,7 @@ static void buffer_pipe_buf_get(struct pipe_inode_info *pipe,
 }
 
 /* Pipe buffer operations for a buffer. */
-static struct pipe_buf_operations buffer_pipe_buf_ops = {
+static const struct pipe_buf_operations buffer_pipe_buf_ops = {
         .can_merge              = 0,
         .map                    = generic_pipe_buf_map,
         .unmap                  = generic_pipe_buf_unmap,
@@ -3647,6 +3771,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
                 len &= PAGE_MASK;
         }
 
+        trace_access_lock(info->cpu);
         entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu);
 
         for (i = 0; i < PIPE_BUFFERS && len && entries; i++, len -= PAGE_SIZE) {
@@ -3694,6 +3819,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
                 entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu);
         }
 
+        trace_access_unlock(info->cpu);
         spd.nr_pages = i;
 
         /* did we read anything? */
@@ -3730,7 +3856,7 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 
         s = kmalloc(sizeof(*s), GFP_KERNEL);
         if (!s)
-                return ENOMEM;
+                return -ENOMEM;
 
         trace_seq_init(s);
 
@@ -3920,39 +4046,16 @@ trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
         if (ret < 0)
                 return ret;
 
-        ret = 0;
-        switch (val) {
-        case 0:
-                /* do nothing if already cleared */
-                if (!(topt->flags->val & topt->opt->bit))
-                        break;
-
-                mutex_lock(&trace_types_lock);
-                if (current_trace->set_flag)
-                        ret = current_trace->set_flag(topt->flags->val,
-                                                      topt->opt->bit, 0);
-                mutex_unlock(&trace_types_lock);
-                if (ret)
-                        return ret;
-                topt->flags->val &= ~topt->opt->bit;
-                break;
-        case 1:
-                /* do nothing if already set */
-                if (topt->flags->val & topt->opt->bit)
-                        break;
+        if (val != 0 && val != 1)
+                return -EINVAL;
 
+        if (!!(topt->flags->val & topt->opt->bit) != val) {
                 mutex_lock(&trace_types_lock);
-                if (current_trace->set_flag)
-                        ret = current_trace->set_flag(topt->flags->val,
-                                                      topt->opt->bit, 1);
+                ret = __set_tracer_option(current_trace, topt->flags,
+                                          topt->opt, !val);
                 mutex_unlock(&trace_types_lock);
                 if (ret)
                         return ret;
-                topt->flags->val |= topt->opt->bit;
-                break;
-
-        default:
-                return -EINVAL;
         }
 
         *ppos += cnt;
@@ -4153,6 +4256,8 @@ static __init int tracer_init_debugfs(void)
         struct dentry *d_tracer;
         int cpu;
 
+        trace_access_lock_init();
+
         d_tracer = tracing_init_dentry();
 
         trace_create_file("tracing_enabled", 0644, d_tracer,
@@ -4176,10 +4281,10 @@ static __init int tracer_init_debugfs(void)
 #ifdef CONFIG_TRACER_MAX_TRACE
         trace_create_file("tracing_max_latency", 0644, d_tracer,
                         &tracing_max_latency, &tracing_max_lat_fops);
+#endif
 
         trace_create_file("tracing_thresh", 0644, d_tracer,
                         &tracing_thresh, &tracing_max_lat_fops);
-#endif
 
         trace_create_file("README", 0444, d_tracer,
                         NULL, &tracing_readme_fops);
@@ -4279,8 +4384,8 @@ trace_printk_seq(struct trace_seq *s)
 
 static void __ftrace_dump(bool disable_tracing)
 {
-        static raw_spinlock_t ftrace_dump_lock =
-                (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+        static arch_spinlock_t ftrace_dump_lock =
+                (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
         /* use static because iter can be a bit big for the stack */
         static struct trace_iterator iter;
         unsigned int old_userobj;
@@ -4290,7 +4395,7 @@ static void __ftrace_dump(bool disable_tracing)
 
         /* only one dump */
         local_irq_save(flags);
-        __raw_spin_lock(&ftrace_dump_lock);
+        arch_spin_lock(&ftrace_dump_lock);
         if (dump_ran)
                 goto out;
 
@@ -4365,7 +4470,7 @@ static void __ftrace_dump(bool disable_tracing)
         }
 
  out:
-        __raw_spin_unlock(&ftrace_dump_lock);
+        arch_spin_unlock(&ftrace_dump_lock);
         local_irq_restore(flags);
 }
 
@@ -4387,9 +4492,6 @@ __init static int tracer_alloc_buffers(void)
         if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL))
                 goto out_free_buffer_mask;
 
-        if (!zalloc_cpumask_var(&tracing_reader_cpumask, GFP_KERNEL))
-                goto out_free_tracing_cpumask;
-
         /* To save memory, keep the ring buffer size to its minimum */
         if (ring_buffer_expanded)
                 ring_buf_size = trace_buf_size;
@@ -4426,7 +4528,7 @@ __init static int tracer_alloc_buffers(void)
         /* Allocate the first page for all buffers */
         for_each_tracing_cpu(i) {
                 global_trace.data[i] = &per_cpu(global_trace_cpu, i);
-                max_tr.data[i] = &per_cpu(max_data, i);
+                max_tr.data[i] = &per_cpu(max_tr_data, i);
         }
 
         trace_init_cmdlines();
@@ -4447,8 +4549,6 @@ __init static int tracer_alloc_buffers(void)
         return 0;
 
 out_free_cpumask:
-        free_cpumask_var(tracing_reader_cpumask);
-out_free_tracing_cpumask:
         free_cpumask_var(tracing_cpumask);
 out_free_buffer_mask:
         free_cpumask_var(tracing_buffer_mask);