Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core

10 files changed, 398 insertions, 128 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index c7683fd8a03..538501c6ea5 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -153,7 +153,7 @@ config IRQSOFF_TRACER
         bool "Interrupts-off Latency Tracer"
         default n
         depends on TRACE_IRQFLAGS_SUPPORT
-        depends on GENERIC_TIME
+        depends on !ARCH_USES_GETTIMEOFFSET
         select TRACE_IRQFLAGS
         select GENERIC_TRACER
         select TRACER_MAX_TRACE
@@ -175,7 +175,7 @@ config IRQSOFF_TRACER
 config PREEMPT_TRACER
         bool "Preemption-off Latency Tracer"
         default n
-        depends on GENERIC_TIME
+        depends on !ARCH_USES_GETTIMEOFFSET
         depends on PREEMPT
         select GENERIC_TRACER
         select TRACER_MAX_TRACE
@@ -323,17 +323,6 @@ config STACK_TRACER
 
           Say N if unsure.
 
-config WORKQUEUE_TRACER
-        bool "Trace workqueues"
-        select GENERIC_TRACER
-        help
-          The workqueue tracer provides some statistical information
-          about each cpu workqueue thread such as the number of the
-          works inserted and executed since their creation. It can help
-          to evaluate the amount of work each of them has to perform.
-          For example it can help a developer to decide whether he should
-          choose a per-cpu workqueue instead of a singlethreaded one.
-
 config BLK_DEV_IO_TRACE
         bool "Support for tracing block IO actions"
         depends on SYSFS
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 438e84a56ab..53f338190b2 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -53,5 +53,8 @@ endif
 obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o
 obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o
 obj-$(CONFIG_EVENT_TRACING) += power-traces.o
+ifeq ($(CONFIG_TRACING),y)
+obj-$(CONFIG_KGDB_KDB) += trace_kdb.o
+endif
 
 libftrace-y := ftrace.o
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 638711c1750..959f8d6c8cc 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -169,9 +169,12 @@ static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
 static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
                                  BLK_TC_ACT(BLK_TC_WRITE) };
 
+#define BLK_TC_HARDBARRIER      BLK_TC_BARRIER
+#define BLK_TC_RAHEAD           BLK_TC_AHEAD
+
 /* The ilog2() calls fall out because they're constant */
-#define MASK_TC_BIT(rw, __name) ((rw & (1 << BIO_RW_ ## __name)) << \
-          (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __name))
+#define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \
+          (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name))
 
 /*
  * The worker for the various blk_add_trace*() types. Fills out a
@@ -194,9 +197,9 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
                 return;
 
         what |= ddir_act[rw & WRITE];
-        what |= MASK_TC_BIT(rw, BARRIER);
-        what |= MASK_TC_BIT(rw, SYNCIO);
-        what |= MASK_TC_BIT(rw, AHEAD);
+        what |= MASK_TC_BIT(rw, HARDBARRIER);
+        what |= MASK_TC_BIT(rw, SYNC);
+        what |= MASK_TC_BIT(rw, RAHEAD);
         what |= MASK_TC_BIT(rw, META);
         what |= MASK_TC_BIT(rw, DISCARD);
 
@@ -549,6 +552,41 @@ int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 }
 EXPORT_SYMBOL_GPL(blk_trace_setup);
 
+#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
+static int compat_blk_trace_setup(struct request_queue *q, char *name,
+                                  dev_t dev, struct block_device *bdev,
+                                  char __user *arg)
+{
+        struct blk_user_trace_setup buts;
+        struct compat_blk_user_trace_setup cbuts;
+        int ret;
+
+        if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
+                return -EFAULT;
+
+        buts = (struct blk_user_trace_setup) {
+                .act_mask = cbuts.act_mask,
+                .buf_size = cbuts.buf_size,
+                .buf_nr = cbuts.buf_nr,
+                .start_lba = cbuts.start_lba,
+                .end_lba = cbuts.end_lba,
+                .pid = cbuts.pid,
+        };
+        memcpy(&buts.name, &cbuts.name, 32);
+
+        ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
+        if (ret)
+                return ret;
+
+        if (copy_to_user(arg, &buts.name, 32)) {
+                blk_trace_remove(q);
+                return -EFAULT;
+        }
+
+        return 0;
+}
+#endif
+
 int blk_trace_startstop(struct request_queue *q, int start)
 {
         int ret;
@@ -601,6 +639,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
         if (!q)
                 return -ENXIO;
 
+        lock_kernel();
         mutex_lock(&bdev->bd_mutex);
 
         switch (cmd) {
@@ -608,6 +647,12 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
                 bdevname(bdev, b);
                 ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
                 break;
+#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
+        case BLKTRACESETUP32:
+                bdevname(bdev, b);
+                ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
+                break;
+#endif
         case BLKTRACESTART:
                 start = 1;
         case BLKTRACESTOP:
@@ -622,6 +667,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
         }
 
         mutex_unlock(&bdev->bd_mutex);
+        unlock_kernel();
         return ret;
 }
 
@@ -661,10 +707,13 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
         if (likely(!bt))
                 return;
 
-        if (blk_discard_rq(rq))
-                rw |= (1 << BIO_RW_DISCARD);
+        if (rq->cmd_flags & REQ_DISCARD)
+                rw |= REQ_DISCARD;
+
+        if (rq->cmd_flags & REQ_SECURE)
+                rw |= REQ_SECURE;
 
-        if (blk_pc_request(rq)) {
+        if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
                 what |= BLK_TC_ACT(BLK_TC_PC);
                 __blk_add_trace(bt, 0, blk_rq_bytes(rq), rw,
                                 what, rq->errors, rq->cmd_len, rq->cmd);
@@ -925,7 +974,7 @@ void blk_add_driver_data(struct request_queue *q,
         if (likely(!bt))
                 return;
 
-        if (blk_pc_request(rq))
+        if (rq->cmd_type == REQ_TYPE_BLOCK_PC)
                 __blk_add_trace(bt, 0, blk_rq_bytes(rq), 0,
                                 BLK_TA_DRV_DATA, rq->errors, len, data);
         else
@@ -1730,7 +1779,7 @@ void blk_dump_cmd(char *buf, struct request *rq)
         int len = rq->cmd_len;
         unsigned char *cmd = rq->cmd;
 
-        if (!blk_pc_request(rq)) {
+        if (rq->cmd_type != REQ_TYPE_BLOCK_PC) {
                 buf[0] = '\0';
                 return;
         }
@@ -1755,21 +1804,23 @@ void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
 
         if (rw & WRITE)
                 rwbs[i++] = 'W';
-        else if (rw & 1 << BIO_RW_DISCARD)
+        else if (rw & REQ_DISCARD)
                 rwbs[i++] = 'D';
         else if (bytes)
                 rwbs[i++] = 'R';
         else
                 rwbs[i++] = 'N';
 
-        if (rw & 1 << BIO_RW_AHEAD)
+        if (rw & REQ_RAHEAD)
                 rwbs[i++] = 'A';
-        if (rw & 1 << BIO_RW_BARRIER)
+        if (rw & REQ_HARDBARRIER)
                 rwbs[i++] = 'B';
-        if (rw & 1 << BIO_RW_SYNCIO)
+        if (rw & REQ_SYNC)
                 rwbs[i++] = 'S';
-        if (rw & 1 << BIO_RW_META)
+        if (rw & REQ_META)
                 rwbs[i++] = 'M';
+        if (rw & REQ_SECURE)
+                rwbs[i++] = 'E';
 
         rwbs[i] = '\0';
 }
@@ -1779,8 +1830,11 @@ void blk_fill_rwbs_rq(char *rwbs, struct request *rq)
         int rw = rq->cmd_flags & 0x03;
         int bytes;
 
-        if (blk_discard_rq(rq))
-                rw |= (1 << BIO_RW_DISCARD);
+        if (rq->cmd_flags & REQ_DISCARD)
+                rw |= REQ_DISCARD;
+
+        if (rq->cmd_flags & REQ_SECURE)
+                rw |= REQ_SECURE;
 
         bytes = blk_rq_bytes(rq);
 
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 3632ce87674..19cccc3c302 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3846,6 +3846,9 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
                         rpos = reader->read;
                         pos += size;
 
+                        if (rpos >= commit)
+                                break;
+
                         event = rb_reader_event(cpu_buffer);
                         size = rb_event_length(event);
                 } while (len > size);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4b1122d0df3..9ec59f54115 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -101,10 +101,7 @@ static inline void ftrace_enable_cpu(void)
         preempt_enable();
 }
 
-static cpumask_var_t __read_mostly      tracing_buffer_mask;
-
-#define for_each_tracing_cpu(cpu)       \
-        for_each_cpu(cpu, tracing_buffer_mask)
+cpumask_var_t __read_mostly     tracing_buffer_mask;
 
 /*
  * ftrace_dump_on_oops - variable to dump ftrace buffer on oops
@@ -744,13 +741,6 @@ __acquires(kernel_lock)
                 return -1;
         }
 
-        /*
-         * When this gets called we hold the BKL which means that
-         * preemption is disabled. Various trace selftests however
-         * need to disable and enable preemption for successful tests.
-         * So we drop the BKL here and grab it after the tests again.
-         */
-        unlock_kernel();
         mutex_lock(&trace_types_lock);
 
         tracing_selftest_running = true;
@@ -832,7 +822,6 @@ __acquires(kernel_lock)
 #endif
 
  out_unlock:
-        lock_kernel();
         return ret;
 }
 
@@ -1493,11 +1482,6 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 }
 EXPORT_SYMBOL_GPL(trace_vprintk);
 
-enum trace_file_type {
-        TRACE_FILE_LAT_FMT      = 1,
-        TRACE_FILE_ANNOTATE     = 2,
-};
-
 static void trace_iterator_increment(struct trace_iterator *iter)
 {
         /* Don't allow ftrace to trace into the ring buffers */
@@ -1595,7 +1579,7 @@ struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 }
 
 /* Find the next real entry, and increment the iterator to the next entry */
-static void *find_next_entry_inc(struct trace_iterator *iter)
+void *trace_find_next_entry_inc(struct trace_iterator *iter)
 {
         iter->ent = __find_next_entry(iter, &iter->cpu,
                                       &iter->lost_events, &iter->ts);
@@ -1630,19 +1614,19 @@ static void *s_next(struct seq_file *m, void *v, loff_t *pos)
                 return NULL;
 
         if (iter->idx < 0)
-                ent = find_next_entry_inc(iter);
+                ent = trace_find_next_entry_inc(iter);
         else
                 ent = iter;
 
         while (ent && iter->idx < i)
-                ent = find_next_entry_inc(iter);
+                ent = trace_find_next_entry_inc(iter);
 
         iter->pos = *pos;
 
         return ent;
 }
 
-static void tracing_iter_reset(struct trace_iterator *iter, int cpu)
+void tracing_iter_reset(struct trace_iterator *iter, int cpu)
 {
         struct trace_array *tr = iter->tr;
         struct ring_buffer_event *event;
@@ -2003,7 +1987,7 @@ int trace_empty(struct trace_iterator *iter)
 }
 
 /*  Called with trace_event_read_lock() held. */
-static enum print_line_t print_trace_line(struct trace_iterator *iter)
+enum print_line_t print_trace_line(struct trace_iterator *iter)
 {
         enum print_line_t ret;
 
@@ -3193,7 +3177,7 @@ waitagain:
 
         trace_event_read_lock();
         trace_access_lock(iter->cpu_file);
-        while (find_next_entry_inc(iter) != NULL) {
+        while (trace_find_next_entry_inc(iter) != NULL) {
                 enum print_line_t ret;
                 int len = iter->seq.len;
 
@@ -3276,7 +3260,7 @@ tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
                 if (ret != TRACE_TYPE_NO_CONSUME)
                         trace_consume(iter);
                 rem -= count;
-                if (!find_next_entry_inc(iter)) {
+                if (!trace_find_next_entry_inc(iter))   {
                         rem = 0;
                         iter->ent = NULL;
                         break;
@@ -3332,7 +3316,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
         if (ret <= 0)
                 goto out_err;
 
-        if (!iter->ent && !find_next_entry_inc(iter)) {
+        if (!iter->ent && !trace_find_next_entry_inc(iter)) {
                 ret = -EFAULT;
                 goto out_err;
         }
@@ -3479,6 +3463,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
                                         size_t cnt, loff_t *fpos)
 {
         char *buf;
+        size_t written;
 
         if (tracing_disabled)
                 return -EINVAL;
@@ -3500,11 +3485,15 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
         } else
                 buf[cnt] = '\0';
 
-        cnt = mark_printk("%s", buf);
+        written = mark_printk("%s", buf);
         kfree(buf);
-        *fpos += cnt;
+        *fpos += written;
 
-        return cnt;
+        /* don't tell userspace we wrote more - it might confuse them */
+        if (written > cnt)
+                written = cnt;
+
+        return written;
 }
 
 static int tracing_clock_show(struct seq_file *m, void *v)
@@ -4402,7 +4391,7 @@ static struct notifier_block trace_die_notifier = {
  */
 #define KERN_TRACE              KERN_EMERG
 
-static void
+void
 trace_printk_seq(struct trace_seq *s)
 {
         /* Probably should print a warning here. */
@@ -4417,6 +4406,13 @@ trace_printk_seq(struct trace_seq *s)
         trace_seq_init(s);
 }
 
+void trace_init_global_iter(struct trace_iterator *iter)
+{
+        iter->tr = &global_trace;
+        iter->trace = current_trace;
+        iter->cpu_file = TRACE_PIPE_ALL_CPU;
+}
+
 static void
 __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
 {
@@ -4442,8 +4438,10 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
         if (disable_tracing)
                 ftrace_kill();
 
+        trace_init_global_iter(&iter);
+
         for_each_tracing_cpu(cpu) {
-                atomic_inc(&global_trace.data[cpu]->disabled);
+                atomic_inc(&iter.tr->data[cpu]->disabled);
         }
 
         old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ;
@@ -4492,7 +4490,7 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
                 iter.iter_flags |= TRACE_FILE_LAT_FMT;
                 iter.pos = -1;
 
-                if (find_next_entry_inc(&iter) != NULL) {
+                if (trace_find_next_entry_inc(&iter) != NULL) {
                         int ret;
 
                         ret = print_trace_line(&iter);
@@ -4514,7 +4512,7 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
                 trace_flags |= old_userobj;
 
                 for_each_tracing_cpu(cpu) {
-                        atomic_dec(&global_trace.data[cpu]->disabled);
+                        atomic_dec(&iter.tr->data[cpu]->disabled);
                 }
                 tracing_on();
         }
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index d05c873dd4b..d39b3c5454a 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -314,6 +314,14 @@ struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
                                           int *ent_cpu, u64 *ent_ts);
 
+int trace_empty(struct trace_iterator *iter);
+
+void *trace_find_next_entry_inc(struct trace_iterator *iter);
+
+void trace_init_global_iter(struct trace_iterator *iter);
+
+void tracing_iter_reset(struct trace_iterator *iter, int cpu);
+
 void default_wait_pipe(struct trace_iterator *iter);
 void poll_wait_pipe(struct trace_iterator *iter);
 
@@ -351,6 +359,15 @@ void tracing_start_sched_switch_record(void);
 int register_tracer(struct tracer *type);
 void unregister_tracer(struct tracer *type);
 int is_tracing_stopped(void);
+enum trace_file_type {
+        TRACE_FILE_LAT_FMT      = 1,
+        TRACE_FILE_ANNOTATE     = 2,
+};
+
+extern cpumask_var_t __read_mostly tracing_buffer_mask;
+
+#define for_each_tracing_cpu(cpu)       \
+        for_each_cpu(cpu, tracing_buffer_mask)
 
 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 
@@ -436,6 +453,8 @@ trace_array_vprintk(struct trace_array *tr,
                     unsigned long ip, const char *fmt, va_list args);
 int trace_array_printk(struct trace_array *tr,
                        unsigned long ip, const char *fmt, ...);
+void trace_printk_seq(struct trace_seq *s);
+enum print_line_t print_trace_line(struct trace_iterator *iter);
 
 extern unsigned long trace_flags;
 
diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c
index 52fda6c04ac..685a67d55db 100644
--- a/kernel/trace/trace_clock.c
+++ b/kernel/trace/trace_clock.c
@@ -55,7 +55,7 @@ u64 notrace trace_clock_local(void)
  */
 u64 notrace trace_clock(void)
 {
-        return cpu_clock(raw_smp_processor_id());
+        return local_clock();
 }
 
 
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 09b4fa6e4d3..398c0e8b332 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -598,88 +598,146 @@ out:
         return ret;
 }
 
-static void print_event_fields(struct trace_seq *s, struct list_head *head)
+enum {
+        FORMAT_HEADER           = 1,
+        FORMAT_FIELD_SEPERATOR  = 2,
+        FORMAT_PRINTFMT         = 3,
+};
+
+static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 {
+        struct ftrace_event_call *call = m->private;
         struct ftrace_event_field *field;
+        struct list_head *common_head = &ftrace_common_fields;
+        struct list_head *head = trace_get_fields(call);
 
-        list_for_each_entry_reverse(field, head, link) {
-                /*
-                 * Smartly shows the array type(except dynamic array).
-                 * Normal:
-                 *      field:TYPE VAR
-                 * If TYPE := TYPE[LEN], it is shown:
-                 *      field:TYPE VAR[LEN]
-                 */
-                const char *array_descriptor = strchr(field->type, '[');
+        (*pos)++;
 
-                if (!strncmp(field->type, "__data_loc", 10))
-                        array_descriptor = NULL;
+        switch ((unsigned long)v) {
+        case FORMAT_HEADER:
+                if (unlikely(list_empty(common_head)))
+                        return NULL;
 
-                if (!array_descriptor) {
-                        trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;"
-                                        "\tsize:%u;\tsigned:%d;\n",
-                                        field->type, field->name, field->offset,
-                                        field->size, !!field->is_signed);
-                } else {
-                        trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;"
-                                        "\tsize:%u;\tsigned:%d;\n",
-                                        (int)(array_descriptor - field->type),
-                                        field->type, field->name,
-                                        array_descriptor, field->offset,
-                                        field->size, !!field->is_signed);
-                }
+                field = list_entry(common_head->prev,
+                                   struct ftrace_event_field, link);
+                return field;
+
+        case FORMAT_FIELD_SEPERATOR:
+                if (unlikely(list_empty(head)))
+                        return NULL;
+
+                field = list_entry(head->prev, struct ftrace_event_field, link);
+                return field;
+
+        case FORMAT_PRINTFMT:
+                /* all done */
+                return NULL;
         }
+
+        field = v;
+        if (field->link.prev == common_head)
+                return (void *)FORMAT_FIELD_SEPERATOR;
+        else if (field->link.prev == head)
+                return (void *)FORMAT_PRINTFMT;
+
+        field = list_entry(field->link.prev, struct ftrace_event_field, link);
+
+        return field;
 }
 
-static ssize_t
-event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
-                  loff_t *ppos)
+static void *f_start(struct seq_file *m, loff_t *pos)
 {
-        struct ftrace_event_call *call = filp->private_data;
-        struct list_head *head;
-        struct trace_seq *s;
-        char *buf;
-        int r;
+        loff_t l = 0;
+        void *p;
 
-        if (*ppos)
+        /* Start by showing the header */
+        if (!*pos)
+                return (void *)FORMAT_HEADER;
+
+        p = (void *)FORMAT_HEADER;
+        do {
+                p = f_next(m, p, &l);
+        } while (p && l < *pos);
+
+        return p;
+}
+
+static int f_show(struct seq_file *m, void *v)
+{
+        struct ftrace_event_call *call = m->private;
+        struct ftrace_event_field *field;
+        const char *array_descriptor;
+
+        switch ((unsigned long)v) {
+        case FORMAT_HEADER:
+                seq_printf(m, "name: %s\n", call->name);
+                seq_printf(m, "ID: %d\n", call->event.type);
+                seq_printf(m, "format:\n");
                 return 0;
 
-        s = kmalloc(sizeof(*s), GFP_KERNEL);
-        if (!s)
-                return -ENOMEM;
+        case FORMAT_FIELD_SEPERATOR:
+                seq_putc(m, '\n');
+                return 0;
 
-        trace_seq_init(s);
+        case FORMAT_PRINTFMT:
+                seq_printf(m, "\nprint fmt: %s\n",
+                           call->print_fmt);
+                return 0;
+        }
 
-        trace_seq_printf(s, "name: %s\n", call->name);
-        trace_seq_printf(s, "ID: %d\n", call->event.type);
-        trace_seq_printf(s, "format:\n");
+        field = v;
 
-        /* print common fields */
-        print_event_fields(s, &ftrace_common_fields);
+        /*
+         * Smartly shows the array type(except dynamic array).
+         * Normal:
+         *      field:TYPE VAR
+         * If TYPE := TYPE[LEN], it is shown:
+         *      field:TYPE VAR[LEN]
+         */
+        array_descriptor = strchr(field->type, '[');
 
-        trace_seq_putc(s, '\n');
+        if (!strncmp(field->type, "__data_loc", 10))
+                array_descriptor = NULL;
 
-        /* print event specific fields */
-        head = trace_get_fields(call);
-        print_event_fields(s, head);
+        if (!array_descriptor)
+                seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
+                           field->type, field->name, field->offset,
+                           field->size, !!field->is_signed);
+        else
+                seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
+                           (int)(array_descriptor - field->type),
+                           field->type, field->name,
+                           array_descriptor, field->offset,
+                           field->size, !!field->is_signed);
 
-        r = trace_seq_printf(s, "\nprint fmt: %s\n", call->print_fmt);
+        return 0;
+}
 
-        if (!r) {
-                /*
-                 * ug!  The format output is bigger than a PAGE!!
-                 */
-                buf = "FORMAT TOO BIG\n";
-                r = simple_read_from_buffer(ubuf, cnt, ppos,
-                                              buf, strlen(buf));
-                goto out;
-        }
+static void f_stop(struct seq_file *m, void *p)
+{
+}
 
-        r = simple_read_from_buffer(ubuf, cnt, ppos,
-                                    s->buffer, s->len);
- out:
-        kfree(s);
-        return r;
+static const struct seq_operations trace_format_seq_ops = {
+        .start          = f_start,
+        .next           = f_next,
+        .stop           = f_stop,
+        .show           = f_show,
+};
+
+static int trace_format_open(struct inode *inode, struct file *file)
+{
+        struct ftrace_event_call *call = inode->i_private;
+        struct seq_file *m;
+        int ret;
+
+        ret = seq_open(file, &trace_format_seq_ops);
+        if (ret < 0)
+                return ret;
+
+        m = file->private_data;
+        m->private = call;
+
+        return 0;
 }
 
 static ssize_t
@@ -877,8 +935,10 @@ static const struct file_operations ftrace_enable_fops = {
 };
 
 static const struct file_operations ftrace_event_format_fops = {
-        .open = tracing_open_generic,
-        .read = event_format_read,
+        .open = trace_format_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = seq_release,
 };
 
 static const struct file_operations ftrace_event_id_fops = {
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index fcb5a542cd2..c93bcb24863 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -507,7 +507,15 @@ get_return_for_leaf(struct trace_iterator *iter,
                          * if the output fails.
                          */
                         data->ent = *curr;
-                        data->ret = *next;
+                        /*
+                         * If the next event is not a return type, then
+                         * we only care about what type it is. Otherwise we can
+                         * safely copy the entire event.
+                         */
+                        if (next->ent.type == TRACE_GRAPH_RET)
+                                data->ret = *next;
+                        else
+                                data->ret.ent.type = next->ent.type;
                 }
         }
 
diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
new file mode 100644
index 00000000000..7b8ecd751d9
--- /dev/null
+++ b/kernel/trace/trace_kdb.c
@@ -0,0 +1,136 @@
+/*
+ * kdb helper for dumping the ftrace buffer
+ *
+ * Copyright (C) 2010 Jason Wessel <jason.wessel@windriver.com>
+ *
+ * ftrace_dump_buf based on ftrace_dump:
+ * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
+ * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
+ *
+ */
+#include <linux/init.h>
+#include <linux/kgdb.h>
+#include <linux/kdb.h>
+#include <linux/ftrace.h>
+
+#include "../debug/kdb/kdb_private.h"
+#include "trace.h"
+#include "trace_output.h"
+
+static void ftrace_dump_buf(int skip_lines, long cpu_file)
+{
+        /* use static because iter can be a bit big for the stack */
+        static struct trace_iterator iter;
+        unsigned int old_userobj;
+        int cnt = 0, cpu;
+
+        trace_init_global_iter(&iter);
+
+        for_each_tracing_cpu(cpu) {
+                atomic_inc(&iter.tr->data[cpu]->disabled);
+        }
+
+        old_userobj = trace_flags;
+
+        /* don't look at user memory in panic mode */
+        trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
+
+        kdb_printf("Dumping ftrace buffer:\n");
+
+        /* reset all but tr, trace, and overruns */
+        memset(&iter.seq, 0,
+                   sizeof(struct trace_iterator) -
+                   offsetof(struct trace_iterator, seq));
+        iter.iter_flags |= TRACE_FILE_LAT_FMT;
+        iter.pos = -1;
+
+        if (cpu_file == TRACE_PIPE_ALL_CPU) {
+                for_each_tracing_cpu(cpu) {
+                        iter.buffer_iter[cpu] =
+                        ring_buffer_read_prepare(iter.tr->buffer, cpu);
+                        ring_buffer_read_start(iter.buffer_iter[cpu]);
+                        tracing_iter_reset(&iter, cpu);
+                }
+        } else {
+                iter.cpu_file = cpu_file;
+                iter.buffer_iter[cpu_file] =
+                        ring_buffer_read_prepare(iter.tr->buffer, cpu_file);
+                ring_buffer_read_start(iter.buffer_iter[cpu_file]);
+                tracing_iter_reset(&iter, cpu_file);
+        }
+        if (!trace_empty(&iter))
+                trace_find_next_entry_inc(&iter);
+        while (!trace_empty(&iter)) {
+                if (!cnt)
+                        kdb_printf("---------------------------------\n");
+                cnt++;
+
+                if (trace_find_next_entry_inc(&iter) != NULL && !skip_lines)
+                        print_trace_line(&iter);
+                if (!skip_lines)
+                        trace_printk_seq(&iter.seq);
+                else
+                        skip_lines--;
+                if (KDB_FLAG(CMD_INTERRUPT))
+                        goto out;
+        }
+
+        if (!cnt)
+                kdb_printf("   (ftrace buffer empty)\n");
+        else
+                kdb_printf("---------------------------------\n");
+
+out:
+        trace_flags = old_userobj;
+
+        for_each_tracing_cpu(cpu) {
+                atomic_dec(&iter.tr->data[cpu]->disabled);
+        }
+
+        for_each_tracing_cpu(cpu)
+                if (iter.buffer_iter[cpu])
+                        ring_buffer_read_finish(iter.buffer_iter[cpu]);
+}
+
+/*
+ * kdb_ftdump - Dump the ftrace log buffer
+ */
+static int kdb_ftdump(int argc, const char **argv)
+{
+        int skip_lines = 0;
+        long cpu_file;
+        char *cp;
+
+        if (argc > 2)
+                return KDB_ARGCOUNT;
+
+        if (argc) {
+                skip_lines = simple_strtol(argv[1], &cp, 0);
+                if (*cp)
+                        skip_lines = 0;
+        }
+
+        if (argc == 2) {
+                cpu_file = simple_strtol(argv[2], &cp, 0);
+                if (*cp || cpu_file >= NR_CPUS || cpu_file < 0 ||
+                    !cpu_online(cpu_file))
+                        return KDB_BADINT;
+        } else {
+                cpu_file = TRACE_PIPE_ALL_CPU;
+        }
+
+        kdb_trap_printk++;
+        ftrace_dump_buf(skip_lines, cpu_file);
+        kdb_trap_printk--;
+
+        return 0;
+}
+
+static __init int kdb_ftrace_register(void)
+{
+        kdb_register_repeat("ftdump", kdb_ftdump, "[skip_#lines] [cpu]",
+                            "Dump ftrace log", 0, KDB_REPEAT_NONE);
+        return 0;
+}
+
+late_initcall(kdb_ftrace_register);