Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[pandora-kernel.git] / kernel / perf_counter.c
index 199ed47..b0b20a0 100644 (file)
@@ -1104,7 +1104,7 @@ static void perf_counter_sync_stat(struct perf_counter_context *ctx,
                __perf_counter_sync_stat(counter, next_counter);
 
                counter = list_next_entry(counter, event_entry);
-               next_counter = list_next_entry(counter, event_entry);
+               next_counter = list_next_entry(next_counter, event_entry);
        }
 }
 
@@ -2714,6 +2714,18 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
                        header.size += sizeof(u64);
        }
 
+       if (sample_type & PERF_SAMPLE_RAW) {
+               int size = sizeof(u32);
+
+               if (data->raw)
+                       size += data->raw->size;
+               else
+                       size += sizeof(u32);
+
+               WARN_ON_ONCE(size & (sizeof(u64)-1));
+               header.size += size;
+       }
+
        ret = perf_output_begin(&handle, counter, header.size, nmi, 1);
        if (ret)
                return;
@@ -2777,6 +2789,22 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
                }
        }
 
+       if (sample_type & PERF_SAMPLE_RAW) {
+               if (data->raw) {
+                       perf_output_put(&handle, data->raw->size);
+                       perf_output_copy(&handle, data->raw->data, data->raw->size);
+               } else {
+                       struct {
+                               u32     size;
+                               u32     data;
+                       } raw = {
+                               .size = sizeof(u32),
+                               .data = 0,
+                       };
+                       perf_output_put(&handle, raw);
+               }
+       }
+
        perf_output_end(&handle);
 }
 
@@ -2840,7 +2868,8 @@ perf_counter_read_event(struct perf_counter *counter,
  */
 
 struct perf_task_event {
-       struct task_struct      *task;
+       struct task_struct              *task;
+       struct perf_counter_context     *task_ctx;
 
        struct {
                struct perf_event_header        header;
@@ -2900,24 +2929,23 @@ static void perf_counter_task_ctx(struct perf_counter_context *ctx,
 static void perf_counter_task_event(struct perf_task_event *task_event)
 {
        struct perf_cpu_context *cpuctx;
-       struct perf_counter_context *ctx;
+       struct perf_counter_context *ctx = task_event->task_ctx;
 
        cpuctx = &get_cpu_var(perf_cpu_context);
        perf_counter_task_ctx(&cpuctx->ctx, task_event);
        put_cpu_var(perf_cpu_context);
 
        rcu_read_lock();
-       /*
-        * doesn't really matter which of the child contexts the
-        * events ends up in.
-        */
-       ctx = rcu_dereference(current->perf_counter_ctxp);
+       if (!ctx)
+               ctx = rcu_dereference(task_event->task->perf_counter_ctxp);
        if (ctx)
                perf_counter_task_ctx(ctx, task_event);
        rcu_read_unlock();
 }
 
-static void perf_counter_task(struct task_struct *task, int new)
+static void perf_counter_task(struct task_struct *task,
+                             struct perf_counter_context *task_ctx,
+                             int new)
 {
        struct perf_task_event task_event;
 
@@ -2927,8 +2955,9 @@ static void perf_counter_task(struct task_struct *task, int new)
                return;
 
        task_event = (struct perf_task_event){
-               .task   = task,
-               .event  = {
+               .task     = task,
+               .task_ctx = task_ctx,
+               .event    = {
                        .header = {
                                .type = new ? PERF_EVENT_FORK : PERF_EVENT_EXIT,
                                .misc = 0,
@@ -2946,7 +2975,7 @@ static void perf_counter_task(struct task_struct *task, int new)
 
 void perf_counter_fork(struct task_struct *task)
 {
-       perf_counter_task(task, 1);
+       perf_counter_task(task, NULL, 1);
 }
 
 /*
@@ -3335,87 +3364,81 @@ int perf_counter_overflow(struct perf_counter *counter, int nmi,
  * Generic software counter infrastructure
  */
 
-static void perf_swcounter_update(struct perf_counter *counter)
+/*
+ * We directly increment counter->count and keep a second value in
+ * counter->hw.period_left to count intervals. This period counter
+ * is kept in the range [-sample_period, 0] so that we can use the
+ * sign as trigger.
+ */
+
+static u64 perf_swcounter_set_period(struct perf_counter *counter)
 {
        struct hw_perf_counter *hwc = &counter->hw;
-       u64 prev, now;
-       s64 delta;
+       u64 period = hwc->last_period;
+       u64 nr, offset;
+       s64 old, val;
+
+       hwc->last_period = hwc->sample_period;
 
 again:
-       prev = atomic64_read(&hwc->prev_count);
-       now = atomic64_read(&hwc->count);
-       if (atomic64_cmpxchg(&hwc->prev_count, prev, now) != prev)
-               goto again;
+       old = val = atomic64_read(&hwc->period_left);
+       if (val < 0)
+               return 0;
 
-       delta = now - prev;
+       nr = div64_u64(period + val, period);
+       offset = nr * period;
+       val -= offset;
+       if (atomic64_cmpxchg(&hwc->period_left, old, val) != old)
+               goto again;
 
-       atomic64_add(delta, &counter->count);
-       atomic64_sub(delta, &hwc->period_left);
+       return nr;
 }
 
-static void perf_swcounter_set_period(struct perf_counter *counter)
+static void perf_swcounter_overflow(struct perf_counter *counter,
+                                   int nmi, struct perf_sample_data *data)
 {
        struct hw_perf_counter *hwc = &counter->hw;
-       s64 left = atomic64_read(&hwc->period_left);
-       s64 period = hwc->sample_period;
+       u64 overflow;
 
-       if (unlikely(left <= -period)) {
-               left = period;
-               atomic64_set(&hwc->period_left, left);
-               hwc->last_period = period;
-       }
+       data->period = counter->hw.last_period;
+       overflow = perf_swcounter_set_period(counter);
 
-       if (unlikely(left <= 0)) {
-               left += period;
-               atomic64_add(period, &hwc->period_left);
-               hwc->last_period = period;
-       }
+       if (hwc->interrupts == MAX_INTERRUPTS)
+               return;
 
-       atomic64_set(&hwc->prev_count, -left);
-       atomic64_set(&hwc->count, -left);
+       for (; overflow; overflow--) {
+               if (perf_counter_overflow(counter, nmi, data)) {
+                       /*
+                        * We inhibit the overflow from happening when
+                        * hwc->interrupts == MAX_INTERRUPTS.
+                        */
+                       break;
+               }
+       }
 }
 
-static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
+static void perf_swcounter_unthrottle(struct perf_counter *counter)
 {
-       enum hrtimer_restart ret = HRTIMER_RESTART;
-       struct perf_sample_data data;
-       struct perf_counter *counter;
-       u64 period;
-
-       counter = container_of(hrtimer, struct perf_counter, hw.hrtimer);
-       counter->pmu->read(counter);
-
-       data.addr = 0;
-       data.regs = get_irq_regs();
        /*
-        * In case we exclude kernel IPs or are somehow not in interrupt
-        * context, provide the next best thing, the user IP.
+        * Nothing to do, we already reset hwc->interrupts.
         */
-       if ((counter->attr.exclude_kernel || !data.regs) &&
-                       !counter->attr.exclude_user)
-               data.regs = task_pt_regs(current);
+}
 
-       if (data.regs) {
-               if (perf_counter_overflow(counter, 0, &data))
-                       ret = HRTIMER_NORESTART;
-       }
+static void perf_swcounter_add(struct perf_counter *counter, u64 nr,
+                              int nmi, struct perf_sample_data *data)
+{
+       struct hw_perf_counter *hwc = &counter->hw;
 
-       period = max_t(u64, 10000, counter->hw.sample_period);
-       hrtimer_forward_now(hrtimer, ns_to_ktime(period));
+       atomic64_add(nr, &counter->count);
 
-       return ret;
-}
+       if (!hwc->sample_period)
+               return;
 
-static void perf_swcounter_overflow(struct perf_counter *counter,
-                                   int nmi, struct perf_sample_data *data)
-{
-       data->period = counter->hw.last_period;
+       if (!data->regs)
+               return;
 
-       perf_swcounter_update(counter);
-       perf_swcounter_set_period(counter);
-       if (perf_counter_overflow(counter, nmi, data))
-               /* soft-disable the counter */
-               ;
+       if (!atomic64_add_negative(nr, &hwc->period_left))
+               perf_swcounter_overflow(counter, nmi, data);
 }
 
 static int perf_swcounter_is_counting(struct perf_counter *counter)
@@ -3479,15 +3502,6 @@ static int perf_swcounter_match(struct perf_counter *counter,
        return 1;
 }
 
-static void perf_swcounter_add(struct perf_counter *counter, u64 nr,
-                              int nmi, struct perf_sample_data *data)
-{
-       int neg = atomic64_add_negative(nr, &counter->hw.count);
-
-       if (counter->hw.sample_period && !neg && data->regs)
-               perf_swcounter_overflow(counter, nmi, data);
-}
-
 static void perf_swcounter_ctx_event(struct perf_counter_context *ctx,
                                     enum perf_type_id type,
                                     u32 event, u64 nr, int nmi,
@@ -3566,26 +3580,65 @@ void __perf_swcounter_event(u32 event, u64 nr, int nmi,
 
 static void perf_swcounter_read(struct perf_counter *counter)
 {
-       perf_swcounter_update(counter);
 }
 
 static int perf_swcounter_enable(struct perf_counter *counter)
 {
-       perf_swcounter_set_period(counter);
+       struct hw_perf_counter *hwc = &counter->hw;
+
+       if (hwc->sample_period) {
+               hwc->last_period = hwc->sample_period;
+               perf_swcounter_set_period(counter);
+       }
        return 0;
 }
 
 static void perf_swcounter_disable(struct perf_counter *counter)
 {
-       perf_swcounter_update(counter);
 }
 
 static const struct pmu perf_ops_generic = {
        .enable         = perf_swcounter_enable,
        .disable        = perf_swcounter_disable,
        .read           = perf_swcounter_read,
+       .unthrottle     = perf_swcounter_unthrottle,
 };
 
+/*
+ * hrtimer based swcounter callback
+ */
+
+static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
+{
+       enum hrtimer_restart ret = HRTIMER_RESTART;
+       struct perf_sample_data data;
+       struct perf_counter *counter;
+       u64 period;
+
+       counter = container_of(hrtimer, struct perf_counter, hw.hrtimer);
+       counter->pmu->read(counter);
+
+       data.addr = 0;
+       data.regs = get_irq_regs();
+       /*
+        * In case we exclude kernel IPs or are somehow not in interrupt
+        * context, provide the next best thing, the user IP.
+        */
+       if ((counter->attr.exclude_kernel || !data.regs) &&
+                       !counter->attr.exclude_user)
+               data.regs = task_pt_regs(current);
+
+       if (data.regs) {
+               if (perf_counter_overflow(counter, 0, &data))
+                       ret = HRTIMER_NORESTART;
+       }
+
+       period = max_t(u64, 10000, counter->hw.sample_period);
+       hrtimer_forward_now(hrtimer, ns_to_ktime(period));
+
+       return ret;
+}
+
 /*
  * Software counter: cpu wall time clock
  */
@@ -3703,17 +3756,24 @@ static const struct pmu perf_ops_task_clock = {
 };
 
 #ifdef CONFIG_EVENT_PROFILE
-void perf_tpcounter_event(int event_id)
+void perf_tpcounter_event(int event_id, u64 addr, u64 count, void *record,
+                         int entry_size)
 {
+       struct perf_raw_record raw = {
+               .size = entry_size,
+               .data = record,
+       };
+
        struct perf_sample_data data = {
                .regs = get_irq_regs(),
-               .addr = 0,
+               .addr = addr,
+               .raw = &raw,
        };
 
        if (!data.regs)
                data.regs = task_pt_regs(current);
 
-       do_perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, 1, 1, &data);
+       do_perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, &data);
 }
 EXPORT_SYMBOL_GPL(perf_tpcounter_event);
 
@@ -3727,6 +3787,14 @@ static void tp_perf_counter_destroy(struct perf_counter *counter)
 
 static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
 {
+       /*
+        * Raw tracepoint data is a severe data leak, only allow root to
+        * have these.
+        */
+       if ((counter->attr.sample_type & PERF_SAMPLE_RAW) &&
+                       !capable(CAP_SYS_ADMIN))
+               return ERR_PTR(-EPERM);
+
        if (ftrace_profile_enable(counter->attr.config))
                return NULL;
 
@@ -4269,7 +4337,7 @@ void perf_counter_exit_task(struct task_struct *child)
        unsigned long flags;
 
        if (likely(!child->perf_counter_ctxp)) {
-               perf_counter_task(child, 0);
+               perf_counter_task(child, NULL, 0);
                return;
        }
 
@@ -4289,6 +4357,7 @@ void perf_counter_exit_task(struct task_struct *child)
         * incremented the context's refcount before we do put_ctx below.
         */
        spin_lock(&child_ctx->lock);
+       child->perf_counter_ctxp = NULL;
        /*
         * If this context is a clone; unclone it so it can't get
         * swapped to another process while we're removing all
@@ -4302,9 +4371,7 @@ void perf_counter_exit_task(struct task_struct *child)
         * won't get any samples after PERF_EVENT_EXIT. We can however still
         * get a few PERF_EVENT_READ events.
         */
-       perf_counter_task(child, 0);
-
-       child->perf_counter_ctxp = NULL;
+       perf_counter_task(child, child_ctx, 0);
 
        /*
         * We can recurse on the same lock type through: