1 files changed, 344 insertions, 184 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 3256e36ad251..6b7ddba1dd64 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -29,6 +29,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/perf_event.h>
 #include <linux/ftrace_event.h>
+#include <linux/hw_breakpoint.h>
 
 #include <asm/irq_regs.h>
 
@@ -245,6 +246,49 @@ static void perf_unpin_context(struct perf_event_context *ctx)
         put_ctx(ctx);
 }
 
+static inline u64 perf_clock(void)
+{
+        return cpu_clock(smp_processor_id());
+}
+
+/*
+ * Update the record of the current time in a context.
+ */
+static void update_context_time(struct perf_event_context *ctx)
+{
+        u64 now = perf_clock();
+
+        ctx->time += now - ctx->timestamp;
+        ctx->timestamp = now;
+}
+
+/*
+ * Update the total_time_enabled and total_time_running fields for a event.
+ */
+static void update_event_times(struct perf_event *event)
+{
+        struct perf_event_context *ctx = event->ctx;
+        u64 run_end;
+
+        if (event->state < PERF_EVENT_STATE_INACTIVE ||
+            event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
+                return;
+
+        if (ctx->is_active)
+                run_end = ctx->time;
+        else
+                run_end = event->tstamp_stopped;
+
+        event->total_time_enabled = run_end - event->tstamp_enabled;
+
+        if (event->state == PERF_EVENT_STATE_INACTIVE)
+                run_end = event->tstamp_stopped;
+        else
+                run_end = ctx->time;
+
+        event->total_time_running = run_end - event->tstamp_running;
+}
+
 /*
  * Add a event from the lists for its context.
  * Must be called with ctx->mutex and ctx->lock held.
@@ -293,6 +337,18 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx)
         if (event->group_leader != event)
                 event->group_leader->nr_siblings--;
 
+        update_event_times(event);
+
+        /*
+         * If event was in error state, then keep it
+         * that way, otherwise bogus counts will be
+         * returned on read(). The only way to get out
+         * of error state is by explicit re-enabling
+         * of the event
+         */
+        if (event->state > PERF_EVENT_STATE_OFF)
+                event->state = PERF_EVENT_STATE_OFF;
+
         /*
          * If this was a group event with sibling events then
          * upgrade the siblings to singleton events by adding them
@@ -446,50 +502,11 @@ retry:
          * can remove the event safely, if the call above did not
          * succeed.
          */
-        if (!list_empty(&event->group_entry)) {
+        if (!list_empty(&event->group_entry))
                 list_del_event(event, ctx);
-        }
         spin_unlock_irq(&ctx->lock);
 }
 
-static inline u64 perf_clock(void)
-{
-        return cpu_clock(smp_processor_id());
-}
-
-/*
- * Update the record of the current time in a context.
- */
-static void update_context_time(struct perf_event_context *ctx)
-{
-        u64 now = perf_clock();
-
-        ctx->time += now - ctx->timestamp;
-        ctx->timestamp = now;
-}
-
-/*
- * Update the total_time_enabled and total_time_running fields for a event.
- */
-static void update_event_times(struct perf_event *event)
-{
-        struct perf_event_context *ctx = event->ctx;
-        u64 run_end;
-
-        if (event->state < PERF_EVENT_STATE_INACTIVE ||
-            event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
-                return;
-
-        event->total_time_enabled = ctx->time - event->tstamp_enabled;
-
-        if (event->state == PERF_EVENT_STATE_INACTIVE)
-                run_end = event->tstamp_stopped;
-        else
-                run_end = ctx->time;
-
-        event->total_time_running = run_end - event->tstamp_running;
-}
-
 /*
  * Update total_time_enabled and total_time_running for all events in a group.
  */
@@ -1032,10 +1049,10 @@ void __perf_event_sched_out(struct perf_event_context *ctx,
         update_context_time(ctx);
 
         perf_disable();
-        if (ctx->nr_active)
+        if (ctx->nr_active) {
                 list_for_each_entry(event, &ctx->group_list, group_entry)
                         group_sched_out(event, cpuctx, ctx);
-
+        }
         perf_enable();
  out:
         spin_unlock(&ctx->lock);
@@ -1060,8 +1077,6 @@ static int context_equiv(struct perf_event_context *ctx1,
                 && !ctx1->pin_count && !ctx2->pin_count;
 }
 
-static void __perf_event_read(void *event);
-
 static void __perf_event_sync_stat(struct perf_event *event,
                                      struct perf_event *next_event)
 {
@@ -1079,8 +1094,8 @@ static void __perf_event_sync_stat(struct perf_event *event,
          */
         switch (event->state) {
         case PERF_EVENT_STATE_ACTIVE:
-                __perf_event_read(event);
-                break;
+                event->pmu->read(event);
+                /* fall-through */
 
         case PERF_EVENT_STATE_INACTIVE:
                 update_event_times(event);
@@ -1119,6 +1134,8 @@ static void perf_event_sync_stat(struct perf_event_context *ctx,
         if (!ctx->nr_stat)
                 return;
 
+        update_context_time(ctx);
+
         event = list_first_entry(&ctx->event_list,
                                    struct perf_event, event_entry);
 
@@ -1162,8 +1179,6 @@ void perf_event_task_sched_out(struct task_struct *task,
         if (likely(!ctx || !cpuctx->task_ctx))
                 return;
 
-        update_context_time(ctx);
-
         rcu_read_lock();
         parent = rcu_dereference(ctx->parent_ctx);
         next_ctx = next->perf_event_ctxp;
@@ -1516,7 +1531,6 @@ static void __perf_event_read(void *info)
         struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
         struct perf_event *event = info;
         struct perf_event_context *ctx = event->ctx;
-        unsigned long flags;
 
         /*
          * If this is a task context, we need to check whether it is
@@ -1528,12 +1542,12 @@ static void __perf_event_read(void *info)
         if (ctx->task && cpuctx->task_ctx != ctx)
                 return;
 
-        local_irq_save(flags);
-        if (ctx->is_active)
-                update_context_time(ctx);
-        event->pmu->read(event);
+        spin_lock(&ctx->lock);
+        update_context_time(ctx);
         update_event_times(event);
-        local_irq_restore(flags);
+        spin_unlock(&ctx->lock);
+
+        event->pmu->read(event);
 }
 
 static u64 perf_event_read(struct perf_event *event)
@@ -1546,7 +1560,13 @@ static u64 perf_event_read(struct perf_event *event)
                 smp_call_function_single(event->oncpu,
                                          __perf_event_read, event, 1);
         } else if (event->state == PERF_EVENT_STATE_INACTIVE) {
+                struct perf_event_context *ctx = event->ctx;
+                unsigned long flags;
+
+                spin_lock_irqsave(&ctx->lock, flags);
+                update_context_time(ctx);
                 update_event_times(event);
+                spin_unlock_irqrestore(&ctx->lock, flags);
         }
 
         return atomic64_read(&event->count);
@@ -1700,16 +1720,10 @@ static void free_event(struct perf_event *event)
         call_rcu(&event->rcu_head, free_event_rcu);
 }
 
-/*
- * Called when the last reference to the file is gone.
- */
-static int perf_release(struct inode *inode, struct file *file)
+int perf_event_release_kernel(struct perf_event *event)
 {
-        struct perf_event *event = file->private_data;
         struct perf_event_context *ctx = event->ctx;
 
-        file->private_data = NULL;
-
         WARN_ON_ONCE(ctx->parent_ctx);
         mutex_lock(&ctx->mutex);
         perf_event_remove_from_context(event);
@@ -1724,6 +1738,19 @@ static int perf_release(struct inode *inode, struct file *file)
 
         return 0;
 }
+EXPORT_SYMBOL_GPL(perf_event_release_kernel);
+
+/*
+ * Called when the last reference to the file is gone.
+ */
+static int perf_release(struct inode *inode, struct file *file)
+{
+        struct perf_event *event = file->private_data;
+
+        file->private_data = NULL;
+
+        return perf_event_release_kernel(event);
+}
 
 static int perf_event_read_size(struct perf_event *event)
 {
@@ -1750,91 +1777,94 @@ static int perf_event_read_size(struct perf_event *event)
         return size;
 }
 
-static u64 perf_event_read_value(struct perf_event *event)
+u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
 {
         struct perf_event *child;
         u64 total = 0;
 
+        *enabled = 0;
+        *running = 0;
+
+        mutex_lock(&event->child_mutex);
         total += perf_event_read(event);
-        list_for_each_entry(child, &event->child_list, child_list)
+        *enabled += event->total_time_enabled +
+                        atomic64_read(&event->child_total_time_enabled);
+        *running += event->total_time_running +
+                        atomic64_read(&event->child_total_time_running);
+
+        list_for_each_entry(child, &event->child_list, child_list) {
                 total += perf_event_read(child);
+                *enabled += child->total_time_enabled;
+                *running += child->total_time_running;
+        }
+        mutex_unlock(&event->child_mutex);
 
         return total;
 }
-
-static int perf_event_read_entry(struct perf_event *event,
-                                   u64 read_format, char __user *buf)
-{
-        int n = 0, count = 0;
-        u64 values[2];
-
-        values[n++] = perf_event_read_value(event);
-        if (read_format & PERF_FORMAT_ID)
-                values[n++] = primary_event_id(event);
-
-        count = n * sizeof(u64);
-
-        if (copy_to_user(buf, values, count))
-                return -EFAULT;
-
-        return count;
-}
+EXPORT_SYMBOL_GPL(perf_event_read_value);
 
 static int perf_event_read_group(struct perf_event *event,
                                    u64 read_format, char __user *buf)
 {
         struct perf_event *leader = event->group_leader, *sub;
-        int n = 0, size = 0, err = -EFAULT;
-        u64 values[3];
+        int n = 0, size = 0, ret = -EFAULT;
+        struct perf_event_context *ctx = leader->ctx;
+        u64 values[5];
+        u64 count, enabled, running;
+
+        mutex_lock(&ctx->mutex);
+        count = perf_event_read_value(leader, &enabled, &running);
 
         values[n++] = 1 + leader->nr_siblings;
-        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
-                values[n++] = leader->total_time_enabled +
-                        atomic64_read(&leader->child_total_time_enabled);
-        }
-        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
-                values[n++] = leader->total_time_running +
-                        atomic64_read(&leader->child_total_time_running);
-        }
+        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+                values[n++] = enabled;
+        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+                values[n++] = running;
+        values[n++] = count;
+        if (read_format & PERF_FORMAT_ID)
+                values[n++] = primary_event_id(leader);
 
         size = n * sizeof(u64);
 
         if (copy_to_user(buf, values, size))
-                return -EFAULT;
-
-        err = perf_event_read_entry(leader, read_format, buf + size);
-        if (err < 0)
-                return err;
+                goto unlock;
 
-        size += err;
+        ret = size;
 
         list_for_each_entry(sub, &leader->sibling_list, group_entry) {
-                err = perf_event_read_entry(sub, read_format,
-                                buf + size);
-                if (err < 0)
-                        return err;
+                n = 0;
+
+                values[n++] = perf_event_read_value(sub, &enabled, &running);
+                if (read_format & PERF_FORMAT_ID)
+                        values[n++] = primary_event_id(sub);
+
+                size = n * sizeof(u64);
+
+                if (copy_to_user(buf + ret, values, size)) {
+                        ret = -EFAULT;
+                        goto unlock;
+                }
 
-                size += err;
+                ret += size;
         }
+unlock:
+        mutex_unlock(&ctx->mutex);
 
-        return size;
+        return ret;
 }
 
 static int perf_event_read_one(struct perf_event *event,
                                  u64 read_format, char __user *buf)
 {
+        u64 enabled, running;
         u64 values[4];
         int n = 0;
 
-        values[n++] = perf_event_read_value(event);
-        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
-                values[n++] = event->total_time_enabled +
-                        atomic64_read(&event->child_total_time_enabled);
-        }
-        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
-                values[n++] = event->total_time_running +
-                        atomic64_read(&event->child_total_time_running);
-        }
+        values[n++] = perf_event_read_value(event, &enabled, &running);
+        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+                values[n++] = enabled;
+        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+                values[n++] = running;
         if (read_format & PERF_FORMAT_ID)
                 values[n++] = primary_event_id(event);
 
@@ -1865,12 +1895,10 @@ perf_read_hw(struct perf_event *event, char __user *buf, size_t count)
                 return -ENOSPC;
 
         WARN_ON_ONCE(event->ctx->parent_ctx);
-        mutex_lock(&event->child_mutex);
         if (read_format & PERF_FORMAT_GROUP)
                 ret = perf_event_read_group(event, read_format, buf);
         else
                 ret = perf_event_read_one(event, read_format, buf);
-        mutex_unlock(&event->child_mutex);
 
         return ret;
 }
@@ -2182,6 +2210,7 @@ static void perf_mmap_data_free(struct perf_mmap_data *data)
         perf_mmap_free_page((unsigned long)data->user_page);
         for (i = 0; i < data->nr_pages; i++)
                 perf_mmap_free_page((unsigned long)data->data_pages[i]);
+        kfree(data);
 }
 
 #else
@@ -2222,6 +2251,7 @@ static void perf_mmap_data_free_work(struct work_struct *work)
                 perf_mmap_unmark_page(base + (i * PAGE_SIZE));
 
         vfree(base);
+        kfree(data);
 }
 
 static void perf_mmap_data_free(struct perf_mmap_data *data)
@@ -2315,7 +2345,7 @@ perf_mmap_data_init(struct perf_event *event, struct perf_mmap_data *data)
         }
 
         if (!data->watermark)
-                data->watermark = max_t(long, PAGE_SIZE, max_size / 2);
+                data->watermark = max_size / 2;
 
 
         rcu_assign_pointer(event->data, data);
@@ -2327,7 +2357,6 @@ static void perf_mmap_data_free_rcu(struct rcu_head *rcu_head)
 
         data = container_of(rcu_head, struct perf_mmap_data, rcu_head);
         perf_mmap_data_free(data);
-        kfree(data);
 }
 
 static void perf_mmap_data_release(struct perf_event *event)
@@ -3245,15 +3274,10 @@ static void perf_event_task_ctx(struct perf_event_context *ctx,
 {
         struct perf_event *event;
 
-        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-                return;
-
-        rcu_read_lock();
         list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
                 if (perf_event_task_match(event))
                         perf_event_task_output(event, task_event);
         }
-        rcu_read_unlock();
 }
 
 static void perf_event_task_event(struct perf_task_event *task_event)
@@ -3261,11 +3285,11 @@ static void perf_event_task_event(struct perf_task_event *task_event)
         struct perf_cpu_context *cpuctx;
         struct perf_event_context *ctx = task_event->task_ctx;
 
+        rcu_read_lock();
         cpuctx = &get_cpu_var(perf_cpu_context);
         perf_event_task_ctx(&cpuctx->ctx, task_event);
         put_cpu_var(perf_cpu_context);
 
-        rcu_read_lock();
         if (!ctx)
                 ctx = rcu_dereference(task_event->task->perf_event_ctxp);
         if (ctx)
@@ -3357,15 +3381,10 @@ static void perf_event_comm_ctx(struct perf_event_context *ctx,
 {
         struct perf_event *event;
 
-        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-                return;
-
-        rcu_read_lock();
         list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
                 if (perf_event_comm_match(event))
                         perf_event_comm_output(event, comm_event);
         }
-        rcu_read_unlock();
 }
 
 static void perf_event_comm_event(struct perf_comm_event *comm_event)
@@ -3376,7 +3395,7 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event)
         char comm[TASK_COMM_LEN];
 
         memset(comm, 0, sizeof(comm));
-        strncpy(comm, comm_event->task->comm, sizeof(comm));
+        strlcpy(comm, comm_event->task->comm, sizeof(comm));
         size = ALIGN(strlen(comm)+1, sizeof(u64));
 
         comm_event->comm = comm;
@@ -3384,11 +3403,11 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event)
 
         comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
 
+        rcu_read_lock();
         cpuctx = &get_cpu_var(perf_cpu_context);
         perf_event_comm_ctx(&cpuctx->ctx, comm_event);
         put_cpu_var(perf_cpu_context);
 
-        rcu_read_lock();
         /*
          * doesn't really matter which of the child contexts the
          * events ends up in.
@@ -3481,15 +3500,10 @@ static void perf_event_mmap_ctx(struct perf_event_context *ctx,
 {
         struct perf_event *event;
 
-        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-                return;
-
-        rcu_read_lock();
         list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
                 if (perf_event_mmap_match(event, mmap_event))
                         perf_event_mmap_output(event, mmap_event);
         }
-        rcu_read_unlock();
 }
 
 static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
@@ -3545,11 +3559,11 @@ got_name:
 
         mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
 
+        rcu_read_lock();
         cpuctx = &get_cpu_var(perf_cpu_context);
         perf_event_mmap_ctx(&cpuctx->ctx, mmap_event);
         put_cpu_var(perf_cpu_context);
 
-        rcu_read_lock();
         /*
          * doesn't really matter which of the child contexts the
          * events ends up in.
@@ -3688,7 +3702,11 @@ static int __perf_event_overflow(struct perf_event *event, int nmi,
                         perf_event_disable(event);
         }
 
-        perf_event_output(event, nmi, data, regs);
+        if (event->overflow_handler)
+                event->overflow_handler(event, nmi, data, regs);
+        else
+                perf_event_output(event, nmi, data, regs);
+
         return ret;
 }
 
@@ -3733,16 +3751,16 @@ again:
         return nr;
 }
 
-static void perf_swevent_overflow(struct perf_event *event,
+static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
                                     int nmi, struct perf_sample_data *data,
                                     struct pt_regs *regs)
 {
         struct hw_perf_event *hwc = &event->hw;
         int throttle = 0;
-        u64 overflow;
 
         data->period = event->hw.last_period;
-        overflow = perf_swevent_set_period(event);
+        if (!overflow)
+                overflow = perf_swevent_set_period(event);
 
         if (hwc->interrupts == MAX_INTERRUPTS)
                 return;
@@ -3775,14 +3793,19 @@ static void perf_swevent_add(struct perf_event *event, u64 nr,
 
         atomic64_add(nr, &event->count);
 
+        if (!regs)
+                return;
+
         if (!hwc->sample_period)
                 return;
 
-        if (!regs)
+        if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
+                return perf_swevent_overflow(event, 1, nmi, data, regs);
+
+        if (atomic64_add_negative(nr, &hwc->period_left))
                 return;
 
-        if (!atomic64_add_negative(nr, &hwc->period_left))
-                perf_swevent_overflow(event, nmi, data, regs);
+        perf_swevent_overflow(event, 0, nmi, data, regs);
 }
 
 static int perf_swevent_is_counting(struct perf_event *event)
@@ -3818,6 +3841,20 @@ static int perf_swevent_is_counting(struct perf_event *event)
 static int perf_tp_event_match(struct perf_event *event,
                                 struct perf_sample_data *data);
 
+static int perf_exclude_event(struct perf_event *event,
+                              struct pt_regs *regs)
+{
+        if (regs) {
+                if (event->attr.exclude_user && user_mode(regs))
+                        return 1;
+
+                if (event->attr.exclude_kernel && !user_mode(regs))
+                        return 1;
+        }
+
+        return 0;
+}
+
 static int perf_swevent_match(struct perf_event *event,
                                 enum perf_type_id type,
                                 u32 event_id,
@@ -3829,16 +3866,12 @@ static int perf_swevent_match(struct perf_event *event,
 
         if (event->attr.type != type)
                 return 0;
+
         if (event->attr.config != event_id)
                 return 0;
 
-        if (regs) {
-                if (event->attr.exclude_user && user_mode(regs))
-                        return 0;
-
-                if (event->attr.exclude_kernel && !user_mode(regs))
-                        return 0;
-        }
+        if (perf_exclude_event(event, regs))
+                return 0;
 
         if (event->attr.type == PERF_TYPE_TRACEPOINT &&
             !perf_tp_event_match(event, data))
@@ -3855,49 +3888,59 @@ static void perf_swevent_ctx_event(struct perf_event_context *ctx,
 {
         struct perf_event *event;
 
-        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-                return;
-
-        rcu_read_lock();
         list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
                 if (perf_swevent_match(event, type, event_id, data, regs))
                         perf_swevent_add(event, nr, nmi, data, regs);
         }
-        rcu_read_unlock();
 }
 
-static int *perf_swevent_recursion_context(struct perf_cpu_context *cpuctx)
+int perf_swevent_get_recursion_context(void)
 {
+        struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
+        int rctx;
+
         if (in_nmi())
-                return &cpuctx->recursion[3];
+                rctx = 3;
+        else if (in_irq())
+                rctx = 2;
+        else if (in_softirq())
+                rctx = 1;
+        else
+                rctx = 0;
 
-        if (in_irq())
-                return &cpuctx->recursion[2];
+        if (cpuctx->recursion[rctx]) {
+                put_cpu_var(perf_cpu_context);
+                return -1;
+        }
 
-        if (in_softirq())
-                return &cpuctx->recursion[1];
+        cpuctx->recursion[rctx]++;
+        barrier();
 
-        return &cpuctx->recursion[0];
+        return rctx;
 }
+EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
+
+void perf_swevent_put_recursion_context(int rctx)
+{
+        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+        barrier();
+        cpuctx->recursion[rctx]--;
+        put_cpu_var(perf_cpu_context);
+}
+EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context);
 
 static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
                                     u64 nr, int nmi,
                                     struct perf_sample_data *data,
                                     struct pt_regs *regs)
 {
-        struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
-        int *recursion = perf_swevent_recursion_context(cpuctx);
+        struct perf_cpu_context *cpuctx;
         struct perf_event_context *ctx;
 
-        if (*recursion)
-                goto out;
-
-        (*recursion)++;
-        barrier();
-
+        cpuctx = &__get_cpu_var(perf_cpu_context);
+        rcu_read_lock();
         perf_swevent_ctx_event(&cpuctx->ctx, type, event_id,
                                  nr, nmi, data, regs);
-        rcu_read_lock();
         /*
          * doesn't really matter which of the child contexts the
          * events ends up in.
@@ -3906,23 +3949,24 @@ static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
         if (ctx)
                 perf_swevent_ctx_event(ctx, type, event_id, nr, nmi, data, regs);
         rcu_read_unlock();
-
-        barrier();
-        (*recursion)--;
-
-out:
-        put_cpu_var(perf_cpu_context);
 }
 
 void __perf_sw_event(u32 event_id, u64 nr, int nmi,
                             struct pt_regs *regs, u64 addr)
 {
-        struct perf_sample_data data = {
-                .addr = addr,
-        };
+        struct perf_sample_data data;
+        int rctx;
 
-        do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi,
-                                &data, regs);
+        rctx = perf_swevent_get_recursion_context();
+        if (rctx < 0)
+                return;
+
+        data.addr = addr;
+        data.raw  = NULL;
+
+        do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, &data, regs);
+
+        perf_swevent_put_recursion_context(rctx);
 }
 
 static void perf_swevent_read(struct perf_event *event)
@@ -3967,6 +4011,7 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
         event->pmu->read(event);
 
         data.addr = 0;
+        data.period = event->hw.last_period;
         regs = get_irq_regs();
         /*
          * In case we exclude kernel IPs or are somehow not in interrupt
@@ -4145,6 +4190,7 @@ void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
         if (!regs)
                 regs = task_pt_regs(current);
 
+        /* Trace events already protected against recursion */
         do_perf_sw_event(PERF_TYPE_TRACEPOINT, event_id, count, 1,
                                 &data, regs);
 }
@@ -4231,6 +4277,53 @@ static void perf_event_free_filter(struct perf_event *event)
 
 #endif /* CONFIG_EVENT_PROFILE */
 
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+static void bp_perf_event_destroy(struct perf_event *event)
+{
+        release_bp_slot(event);
+}
+
+static const struct pmu *bp_perf_event_init(struct perf_event *bp)
+{
+        int err;
+        /*
+         * The breakpoint is already filled if we haven't created the counter
+         * through perf syscall
+         * FIXME: manage to get trigerred to NULL if it comes from syscalls
+         */
+        if (!bp->callback)
+                err = register_perf_hw_breakpoint(bp);
+        else
+                err = __register_perf_hw_breakpoint(bp);
+        if (err)
+                return ERR_PTR(err);
+
+        bp->destroy = bp_perf_event_destroy;
+
+        return &perf_ops_bp;
+}
+
+void perf_bp_event(struct perf_event *bp, void *data)
+{
+        struct perf_sample_data sample;
+        struct pt_regs *regs = data;
+
+        sample.addr = bp->attr.bp_addr;
+
+        if (!perf_exclude_event(bp, regs))
+                perf_swevent_add(bp, 1, 1, &sample, regs);
+}
+#else
+static const struct pmu *bp_perf_event_init(struct perf_event *bp)
+{
+        return NULL;
+}
+
+void perf_bp_event(struct perf_event *bp, void *regs)
+{
+}
+#endif
+
 atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX];
 
 static void sw_perf_event_destroy(struct perf_event *event)
@@ -4297,6 +4390,7 @@ perf_event_alloc(struct perf_event_attr *attr,
                    struct perf_event_context *ctx,
                    struct perf_event *group_leader,
                    struct perf_event *parent_event,
+                   perf_callback_t callback,
                    gfp_t gfpflags)
 {
         const struct pmu *pmu;
@@ -4339,6 +4433,11 @@ perf_event_alloc(struct perf_event_attr *attr,
 
         event->state            = PERF_EVENT_STATE_INACTIVE;
 
+        if (!callback && parent_event)
+                callback = parent_event->callback;
+        
+        event->callback = callback;
+
         if (attr->disabled)
                 event->state = PERF_EVENT_STATE_OFF;
 
@@ -4373,6 +4472,11 @@ perf_event_alloc(struct perf_event_attr *attr,
                 pmu = tp_perf_event_init(event);
                 break;
 
+        case PERF_TYPE_BREAKPOINT:
+                pmu = bp_perf_event_init(event);
+                break;
+
+
         default:
                 break;
         }
@@ -4615,7 +4719,7 @@ SYSCALL_DEFINE5(perf_event_open,
         }
 
         event = perf_event_alloc(&attr, cpu, ctx, group_leader,
-                                     NULL, GFP_KERNEL);
+                                     NULL, NULL, GFP_KERNEL);
         err = PTR_ERR(event);
         if (IS_ERR(event))
                 goto err_put_context;
@@ -4663,6 +4767,60 @@ err_put_context:
         return err;
 }
 
+/**
+ * perf_event_create_kernel_counter
+ *
+ * @attr: attributes of the counter to create
+ * @cpu: cpu in which the counter is bound
+ * @pid: task to profile
+ */
+struct perf_event *
+perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
+                                 pid_t pid, perf_callback_t callback)
+{
+        struct perf_event *event;
+        struct perf_event_context *ctx;
+        int err;
+
+        /*
+         * Get the target context (task or percpu):
+         */
+
+        ctx = find_get_context(pid, cpu);
+        if (IS_ERR(ctx)) {
+                err = PTR_ERR(ctx);
+                goto err_exit;
+        }
+
+        event = perf_event_alloc(attr, cpu, ctx, NULL,
+                                     NULL, callback, GFP_KERNEL);
+        if (IS_ERR(event)) {
+                err = PTR_ERR(event);
+                goto err_put_context;
+        }
+
+        event->filp = NULL;
+        WARN_ON_ONCE(ctx->parent_ctx);
+        mutex_lock(&ctx->mutex);
+        perf_install_in_context(ctx, event, cpu);
+        ++ctx->generation;
+        mutex_unlock(&ctx->mutex);
+
+        event->owner = current;
+        get_task_struct(current);
+        mutex_lock(&current->perf_event_mutex);
+        list_add_tail(&event->owner_entry, &current->perf_event_list);
+        mutex_unlock(&current->perf_event_mutex);
+
+        return event;
+
+ err_put_context:
+        put_ctx(ctx);
+ err_exit:
+        return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
+
 /*
  * inherit a event from parent task to child task:
  */
@@ -4688,7 +4846,7 @@ inherit_event(struct perf_event *parent_event,
         child_event = perf_event_alloc(&parent_event->attr,
                                            parent_event->cpu, child_ctx,
                                            group_leader, parent_event,
-                                           GFP_KERNEL);
+                                           NULL, GFP_KERNEL);
         if (IS_ERR(child_event))
                 return child_event;
         get_ctx(child_ctx);
@@ -4706,6 +4864,8 @@ inherit_event(struct perf_event *parent_event,
         if (parent_event->attr.freq)
                 child_event->hw.sample_period = parent_event->hw.sample_period;
 
+        child_event->overflow_handler = parent_event->overflow_handler;
+
         /*
          * Link it up in the child's context:
          */
@@ -4795,7 +4955,6 @@ __perf_event_exit_task(struct perf_event *child_event,
 {
         struct perf_event *parent_event;
 
-        update_event_times(child_event);
         perf_event_remove_from_context(child_event);
 
         parent_event = child_event->parent;
@@ -4847,6 +5006,7 @@ void perf_event_exit_task(struct task_struct *child)
          * the events from it.
          */
         unclone_ctx(child_ctx);
+        update_context_time(child_ctx);
         spin_unlock_irqrestore(&child_ctx->lock, flags);
 
         /*