Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6
[profile/ivi/kernel-adaptation-intel-automotive.git] / kernel / perf_counter.c
index 195712e..29b685f 100644 (file)
@@ -43,9 +43,30 @@ static atomic_t nr_counters __read_mostly;
 static atomic_t nr_mmap_counters __read_mostly;
 static atomic_t nr_comm_counters __read_mostly;
 
-int sysctl_perf_counter_priv __read_mostly; /* do we need to be privileged */
+/*
+ * perf counter paranoia level:
+ *  0 - not paranoid
+ *  1 - disallow cpu counters to unpriv
+ *  2 - disallow kernel profiling to unpriv
+ */
+int sysctl_perf_counter_paranoid __read_mostly;
+
+static inline bool perf_paranoid_cpu(void)
+{
+       return sysctl_perf_counter_paranoid > 0;
+}
+
+static inline bool perf_paranoid_kernel(void)
+{
+       return sysctl_perf_counter_paranoid > 1;
+}
+
 int sysctl_perf_counter_mlock __read_mostly = 512; /* 'free' kb per user */
-int sysctl_perf_counter_limit __read_mostly = 100000; /* max NMIs per second */
+
+/*
+ * max perf counter sample rate
+ */
+int sysctl_perf_counter_sample_rate __read_mostly = 100000;
 
 static atomic64_t perf_counter_id;
 
@@ -1003,7 +1024,7 @@ void perf_counter_task_sched_out(struct task_struct *task,
        int do_switch = 1;
 
        regs = task_pt_regs(task);
-       perf_swcounter_event(PERF_COUNT_CONTEXT_SWITCHES, 1, 1, regs, 0);
+       perf_swcounter_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0);
 
        if (likely(!ctx || !cpuctx->task_ctx))
                return;
@@ -1184,44 +1205,88 @@ static void perf_counter_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu)
 static void perf_log_throttle(struct perf_counter *counter, int enable);
 static void perf_log_period(struct perf_counter *counter, u64 period);
 
-static void perf_adjust_freq(struct perf_counter_context *ctx)
+static void perf_adjust_period(struct perf_counter *counter, u64 events)
 {
-       struct perf_counter *counter;
-       u64 interrupts, sample_period;
-       u64 events, period;
+       struct hw_perf_counter *hwc = &counter->hw;
+       u64 period, sample_period;
        s64 delta;
 
+       events *= hwc->sample_period;
+       period = div64_u64(events, counter->attr.sample_freq);
+
+       delta = (s64)(period - hwc->sample_period);
+       delta = (delta + 7) / 8; /* low pass filter */
+
+       sample_period = hwc->sample_period + delta;
+
+       if (!sample_period)
+               sample_period = 1;
+
+       perf_log_period(counter, sample_period);
+
+       hwc->sample_period = sample_period;
+}
+
+static void perf_ctx_adjust_freq(struct perf_counter_context *ctx)
+{
+       struct perf_counter *counter;
+       struct hw_perf_counter *hwc;
+       u64 interrupts, freq;
+
        spin_lock(&ctx->lock);
        list_for_each_entry(counter, &ctx->counter_list, list_entry) {
                if (counter->state != PERF_COUNTER_STATE_ACTIVE)
                        continue;
 
-               interrupts = counter->hw.interrupts;
-               counter->hw.interrupts = 0;
+               hwc = &counter->hw;
 
+               interrupts = hwc->interrupts;
+               hwc->interrupts = 0;
+
+               /*
+                * unthrottle counters on the tick
+                */
                if (interrupts == MAX_INTERRUPTS) {
                        perf_log_throttle(counter, 1);
                        counter->pmu->unthrottle(counter);
-                       interrupts = 2*sysctl_perf_counter_limit/HZ;
+                       interrupts = 2*sysctl_perf_counter_sample_rate/HZ;
                }
 
                if (!counter->attr.freq || !counter->attr.sample_freq)
                        continue;
 
-               events = HZ * interrupts * counter->hw.sample_period;
-               period = div64_u64(events, counter->attr.sample_freq);
+               /*
+                * if the specified freq < HZ then we need to skip ticks
+                */
+               if (counter->attr.sample_freq < HZ) {
+                       freq = counter->attr.sample_freq;
 
-               delta = (s64)(1 + period - counter->hw.sample_period);
-               delta >>= 1;
+                       hwc->freq_count += freq;
+                       hwc->freq_interrupts += interrupts;
 
-               sample_period = counter->hw.sample_period + delta;
+                       if (hwc->freq_count < HZ)
+                               continue;
 
-               if (!sample_period)
-                       sample_period = 1;
+                       interrupts = hwc->freq_interrupts;
+                       hwc->freq_interrupts = 0;
+                       hwc->freq_count -= HZ;
+               } else
+                       freq = HZ;
 
-               perf_log_period(counter, sample_period);
+               perf_adjust_period(counter, freq * interrupts);
 
-               counter->hw.sample_period = sample_period;
+               /*
+                * In order to avoid being stalled by an (accidental) huge
+                * sample period, force reset the sample period if we didn't
+                * get any events in this freq period.
+                */
+               if (!interrupts) {
+                       perf_disable();
+                       counter->pmu->disable(counter);
+                       atomic_set(&hwc->period_left, 0);
+                       counter->pmu->enable(counter);
+                       perf_enable();
+               }
        }
        spin_unlock(&ctx->lock);
 }
@@ -1261,9 +1326,9 @@ void perf_counter_task_tick(struct task_struct *curr, int cpu)
        cpuctx = &per_cpu(perf_cpu_context, cpu);
        ctx = curr->perf_counter_ctxp;
 
-       perf_adjust_freq(&cpuctx->ctx);
+       perf_ctx_adjust_freq(&cpuctx->ctx);
        if (ctx)
-               perf_adjust_freq(ctx);
+               perf_ctx_adjust_freq(ctx);
 
        perf_counter_cpu_sched_out(cpuctx);
        if (ctx)
@@ -1341,7 +1406,7 @@ static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
         */
        if (cpu != -1) {
                /* Must be root to operate on a CPU counter: */
-               if (sysctl_perf_counter_priv && !capable(CAP_SYS_ADMIN))
+               if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
                        return ERR_PTR(-EACCES);
 
                if (cpu < 0 || cpu > num_possible_cpus())
@@ -1622,17 +1687,17 @@ static int perf_counter_period(struct perf_counter *counter, u64 __user *arg)
 
        spin_lock_irq(&ctx->lock);
        if (counter->attr.freq) {
-               if (value > sysctl_perf_counter_limit) {
+               if (value > sysctl_perf_counter_sample_rate) {
                        ret = -EINVAL;
                        goto unlock;
                }
 
                counter->attr.sample_freq = value;
        } else {
+               perf_log_period(counter, value);
+
                counter->attr.sample_period = value;
                counter->hw.sample_period = value;
-
-               perf_log_period(counter, value);
        }
 unlock:
        spin_unlock_irq(&ctx->lock);
@@ -2234,7 +2299,7 @@ static int perf_output_begin(struct perf_output_handle *handle,
        perf_output_lock(handle);
 
        do {
-               offset = head = atomic_read(&data->head);
+               offset = head = atomic_long_read(&data->head);
                head += size;
        } while (atomic_long_cmpxchg(&data->head, offset, head) != offset);
 
@@ -2255,7 +2320,7 @@ out:
 }
 
 static void perf_output_copy(struct perf_output_handle *handle,
-                            void *buf, unsigned int len)
+                            const void *buf, unsigned int len)
 {
        unsigned int pages_mask;
        unsigned int offset;
@@ -2334,8 +2399,8 @@ static u32 perf_counter_tid(struct perf_counter *counter, struct task_struct *p)
        return task_pid_nr_ns(p, counter->ns);
 }
 
-static void perf_counter_output(struct perf_counter *counter,
-                               int nmi, struct pt_regs *regs, u64 addr)
+static void perf_counter_output(struct perf_counter *counter, int nmi,
+                               struct perf_sample_data *data)
 {
        int ret;
        u64 sample_type = counter->attr.sample_type;
@@ -2360,10 +2425,10 @@ static void perf_counter_output(struct perf_counter *counter,
        header.size = sizeof(header);
 
        header.misc = PERF_EVENT_MISC_OVERFLOW;
-       header.misc |= perf_misc_flags(regs);
+       header.misc |= perf_misc_flags(data->regs);
 
        if (sample_type & PERF_SAMPLE_IP) {
-               ip = perf_instruction_pointer(regs);
+               ip = perf_instruction_pointer(data->regs);
                header.type |= PERF_SAMPLE_IP;
                header.size += sizeof(ip);
        }
@@ -2392,8 +2457,8 @@ static void perf_counter_output(struct perf_counter *counter,
                header.size += sizeof(u64);
        }
 
-       if (sample_type & PERF_SAMPLE_CONFIG) {
-               header.type |= PERF_SAMPLE_CONFIG;
+       if (sample_type & PERF_SAMPLE_ID) {
+               header.type |= PERF_SAMPLE_ID;
                header.size += sizeof(u64);
        }
 
@@ -2404,6 +2469,11 @@ static void perf_counter_output(struct perf_counter *counter,
                cpu_entry.cpu = raw_smp_processor_id();
        }
 
+       if (sample_type & PERF_SAMPLE_PERIOD) {
+               header.type |= PERF_SAMPLE_PERIOD;
+               header.size += sizeof(u64);
+       }
+
        if (sample_type & PERF_SAMPLE_GROUP) {
                header.type |= PERF_SAMPLE_GROUP;
                header.size += sizeof(u64) +
@@ -2411,7 +2481,7 @@ static void perf_counter_output(struct perf_counter *counter,
        }
 
        if (sample_type & PERF_SAMPLE_CALLCHAIN) {
-               callchain = perf_callchain(regs);
+               callchain = perf_callchain(data->regs);
 
                if (callchain) {
                        callchain_size = (1 + callchain->nr) * sizeof(u64);
@@ -2437,14 +2507,17 @@ static void perf_counter_output(struct perf_counter *counter,
                perf_output_put(&handle, time);
 
        if (sample_type & PERF_SAMPLE_ADDR)
-               perf_output_put(&handle, addr);
+               perf_output_put(&handle, data->addr);
 
-       if (sample_type & PERF_SAMPLE_CONFIG)
-               perf_output_put(&handle, counter->attr.config);
+       if (sample_type & PERF_SAMPLE_ID)
+               perf_output_put(&handle, counter->id);
 
        if (sample_type & PERF_SAMPLE_CPU)
                perf_output_put(&handle, cpu_entry);
 
+       if (sample_type & PERF_SAMPLE_PERIOD)
+               perf_output_put(&handle, data->period);
+
        /*
         * XXX PERF_SAMPLE_GROUP vs inherited counters seems difficult.
         */
@@ -2681,9 +2754,10 @@ void perf_counter_comm(struct task_struct *task)
  */
 
 struct perf_mmap_event {
-       struct file     *file;
-       char            *file_name;
-       int             file_size;
+       struct vm_area_struct   *vma;
+
+       const char              *file_name;
+       int                     file_size;
 
        struct {
                struct perf_event_header        header;
@@ -2744,11 +2818,12 @@ static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event)
 {
        struct perf_cpu_context *cpuctx;
        struct perf_counter_context *ctx;
-       struct file *file = mmap_event->file;
+       struct vm_area_struct *vma = mmap_event->vma;
+       struct file *file = vma->vm_file;
        unsigned int size;
        char tmp[16];
        char *buf = NULL;
-       char *name;
+       const char *name;
 
        if (file) {
                buf = kzalloc(PATH_MAX, GFP_KERNEL);
@@ -2762,6 +2837,15 @@ static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event)
                        goto got_name;
                }
        } else {
+               name = arch_vma_name(mmap_event->vma);
+               if (name)
+                       goto got_name;
+
+               if (!vma->vm_mm) {
+                       name = strncpy(tmp, "[vdso]", sizeof(tmp));
+                       goto got_name;
+               }
+
                name = strncpy(tmp, "//anon", sizeof(tmp));
                goto got_name;
        }
@@ -2791,8 +2875,7 @@ got_name:
        kfree(buf);
 }
 
-void perf_counter_mmap(unsigned long addr, unsigned long len,
-                      unsigned long pgoff, struct file *file)
+void __perf_counter_mmap(struct vm_area_struct *vma)
 {
        struct perf_mmap_event mmap_event;
 
@@ -2800,12 +2883,12 @@ void perf_counter_mmap(unsigned long addr, unsigned long len,
                return;
 
        mmap_event = (struct perf_mmap_event){
-               .file   = file,
+               .vma    = vma,
                .event  = {
                        .header = { .type = PERF_EVENT_MMAP, },
-                       .start  = addr,
-                       .len    = len,
-                       .pgoff  = pgoff,
+                       .start  = vma->vm_start,
+                       .len    = vma->vm_end - vma->vm_start,
+                       .pgoff  = vma->vm_pgoff,
                },
        };
 
@@ -2817,33 +2900,41 @@ void perf_counter_mmap(unsigned long addr, unsigned long len,
  * event flow.
  */
 
+struct freq_event {
+       struct perf_event_header        header;
+       u64                             time;
+       u64                             id;
+       u64                             period;
+};
+
 static void perf_log_period(struct perf_counter *counter, u64 period)
 {
        struct perf_output_handle handle;
+       struct freq_event event;
        int ret;
 
-       struct {
-               struct perf_event_header        header;
-               u64                             time;
-               u64                             period;
-       } freq_event = {
+       if (counter->hw.sample_period == period)
+               return;
+
+       if (counter->attr.sample_type & PERF_SAMPLE_PERIOD)
+               return;
+
+       event = (struct freq_event) {
                .header = {
                        .type = PERF_EVENT_PERIOD,
                        .misc = 0,
-                       .size = sizeof(freq_event),
+                       .size = sizeof(event),
                },
                .time = sched_clock(),
+               .id = counter->id,
                .period = period,
        };
 
-       if (counter->hw.sample_period == period)
-               return;
-
-       ret = perf_output_begin(&handle, counter, sizeof(freq_event), 0, 0);
+       ret = perf_output_begin(&handle, counter, sizeof(event), 1, 0);
        if (ret)
                return;
 
-       perf_output_put(&handle, freq_event);
+       perf_output_put(&handle, event);
        perf_output_end(&handle);
 }
 
@@ -2859,13 +2950,15 @@ static void perf_log_throttle(struct perf_counter *counter, int enable)
        struct {
                struct perf_event_header        header;
                u64                             time;
+               u64                             id;
        } throttle_event = {
                .header = {
                        .type = PERF_EVENT_THROTTLE + 1,
                        .misc = 0,
                        .size = sizeof(throttle_event),
                },
-               .time = sched_clock(),
+               .time   = sched_clock(),
+               .id     = counter->id,
        };
 
        ret = perf_output_begin(&handle, counter, sizeof(throttle_event), 1, 0);
@@ -2880,20 +2973,22 @@ static void perf_log_throttle(struct perf_counter *counter, int enable)
  * Generic counter overflow handling.
  */
 
-int perf_counter_overflow(struct perf_counter *counter,
-                         int nmi, struct pt_regs *regs, u64 addr)
+int perf_counter_overflow(struct perf_counter *counter, int nmi,
+                         struct perf_sample_data *data)
 {
        int events = atomic_read(&counter->event_limit);
        int throttle = counter->pmu->unthrottle != NULL;
+       struct hw_perf_counter *hwc = &counter->hw;
        int ret = 0;
 
        if (!throttle) {
-               counter->hw.interrupts++;
+               hwc->interrupts++;
        } else {
-               if (counter->hw.interrupts != MAX_INTERRUPTS) {
-                       counter->hw.interrupts++;
-                       if (HZ*counter->hw.interrupts > (u64)sysctl_perf_counter_limit) {
-                               counter->hw.interrupts = MAX_INTERRUPTS;
+               if (hwc->interrupts != MAX_INTERRUPTS) {
+                       hwc->interrupts++;
+                       if (HZ * hwc->interrupts >
+                                       (u64)sysctl_perf_counter_sample_rate) {
+                               hwc->interrupts = MAX_INTERRUPTS;
                                perf_log_throttle(counter, 0);
                                ret = 1;
                        }
@@ -2907,6 +3002,16 @@ int perf_counter_overflow(struct perf_counter *counter,
                }
        }
 
+       if (counter->attr.freq) {
+               u64 now = sched_clock();
+               s64 delta = now - hwc->freq_stamp;
+
+               hwc->freq_stamp = now;
+
+               if (delta > 0 && delta < TICK_NSEC)
+                       perf_adjust_period(counter, NSEC_PER_SEC / (int)delta);
+       }
+
        /*
         * XXX event_limit might not quite work as expected on inherited
         * counters
@@ -2924,7 +3029,7 @@ int perf_counter_overflow(struct perf_counter *counter,
                        perf_counter_disable(counter);
        }
 
-       perf_counter_output(counter, nmi, regs, addr);
+       perf_counter_output(counter, nmi, data);
        return ret;
 }
 
@@ -2959,11 +3064,13 @@ static void perf_swcounter_set_period(struct perf_counter *counter)
        if (unlikely(left <= -period)) {
                left = period;
                atomic64_set(&hwc->period_left, left);
+               hwc->last_period = period;
        }
 
        if (unlikely(left <= 0)) {
                left += period;
                atomic64_add(period, &hwc->period_left);
+               hwc->last_period = period;
        }
 
        atomic64_set(&hwc->prev_count, -left);
@@ -2973,24 +3080,25 @@ static void perf_swcounter_set_period(struct perf_counter *counter)
 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;
-       struct pt_regs *regs;
        u64 period;
 
        counter = container_of(hrtimer, struct perf_counter, hw.hrtimer);
        counter->pmu->read(counter);
 
-       regs = get_irq_regs();
+       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 || !regs) &&
+       if ((counter->attr.exclude_kernel || !data.regs) &&
                        !counter->attr.exclude_user)
-               regs = task_pt_regs(current);
+               data.regs = task_pt_regs(current);
 
-       if (regs) {
-               if (perf_counter_overflow(counter, 0, regs, 0))
+       if (data.regs) {
+               if (perf_counter_overflow(counter, 0, &data))
                        ret = HRTIMER_NORESTART;
        }
 
@@ -3003,9 +3111,15 @@ static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
 static void perf_swcounter_overflow(struct perf_counter *counter,
                                    int nmi, struct pt_regs *regs, u64 addr)
 {
+       struct perf_sample_data data = {
+               .regs   = regs,
+               .addr   = addr,
+               .period = counter->hw.last_period,
+       };
+
        perf_swcounter_update(counter);
        perf_swcounter_set_period(counter);
-       if (perf_counter_overflow(counter, nmi, regs, addr))
+       if (perf_counter_overflow(counter, nmi, &data))
                /* soft-disable the counter */
                ;
 
@@ -3050,17 +3164,15 @@ static int perf_swcounter_is_counting(struct perf_counter *counter)
 }
 
 static int perf_swcounter_match(struct perf_counter *counter,
-                               enum perf_event_types type,
+                               enum perf_type_id type,
                                u32 event, struct pt_regs *regs)
 {
-       u64 event_config;
-
-       event_config = ((u64) type << PERF_COUNTER_TYPE_SHIFT) | event;
-
        if (!perf_swcounter_is_counting(counter))
                return 0;
 
-       if (counter->attr.config != event_config)
+       if (counter->attr.type != type)
+               return 0;
+       if (counter->attr.config != event)
                return 0;
 
        if (regs) {
@@ -3084,7 +3196,7 @@ static void perf_swcounter_add(struct perf_counter *counter, u64 nr,
 }
 
 static void perf_swcounter_ctx_event(struct perf_counter_context *ctx,
-                                    enum perf_event_types type, u32 event,
+                                    enum perf_type_id type, u32 event,
                                     u64 nr, int nmi, struct pt_regs *regs,
                                     u64 addr)
 {
@@ -3115,7 +3227,7 @@ static int *perf_swcounter_recursion_context(struct perf_cpu_context *cpuctx)
        return &cpuctx->recursion[0];
 }
 
-static void __perf_swcounter_event(enum perf_event_types type, u32 event,
+static void __perf_swcounter_event(enum perf_type_id type, u32 event,
                                   u64 nr, int nmi, struct pt_regs *regs,
                                   u64 addr)
 {
@@ -3301,13 +3413,13 @@ void perf_counter_task_migration(struct task_struct *task, int cpu)
        struct perf_counter_context *ctx;
 
        perf_swcounter_ctx_event(&cpuctx->ctx, PERF_TYPE_SOFTWARE,
-                                PERF_COUNT_CPU_MIGRATIONS,
+                                PERF_COUNT_SW_CPU_MIGRATIONS,
                                 1, 1, NULL, 0);
 
        ctx = perf_pin_task_context(task);
        if (ctx) {
                perf_swcounter_ctx_event(ctx, PERF_TYPE_SOFTWARE,
-                                        PERF_COUNT_CPU_MIGRATIONS,
+                                        PERF_COUNT_SW_CPU_MIGRATIONS,
                                         1, 1, NULL, 0);
                perf_unpin_context(ctx);
        }
@@ -3343,7 +3455,6 @@ static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
                return NULL;
 
        counter->destroy = tp_perf_counter_destroy;
-       counter->hw.sample_period = counter->attr.sample_period;
 
        return &perf_ops_generic;
 }
@@ -3365,12 +3476,12 @@ static const struct pmu *sw_perf_counter_init(struct perf_counter *counter)
         * to be kernel events, and page faults are never hypervisor
         * events.
         */
-       switch (perf_event_id(&counter->attr)) {
-       case PERF_COUNT_CPU_CLOCK:
+       switch (counter->attr.config) {
+       case PERF_COUNT_SW_CPU_CLOCK:
                pmu = &perf_ops_cpu_clock;
 
                break;
-       case PERF_COUNT_TASK_CLOCK:
+       case PERF_COUNT_SW_TASK_CLOCK:
                /*
                 * If the user instantiates this as a per-cpu counter,
                 * use the cpu_clock counter instead.
@@ -3381,11 +3492,11 @@ static const struct pmu *sw_perf_counter_init(struct perf_counter *counter)
                        pmu = &perf_ops_cpu_clock;
 
                break;
-       case PERF_COUNT_PAGE_FAULTS:
-       case PERF_COUNT_PAGE_FAULTS_MIN:
-       case PERF_COUNT_PAGE_FAULTS_MAJ:
-       case PERF_COUNT_CONTEXT_SWITCHES:
-       case PERF_COUNT_CPU_MIGRATIONS:
+       case PERF_COUNT_SW_PAGE_FAULTS:
+       case PERF_COUNT_SW_PAGE_FAULTS_MIN:
+       case PERF_COUNT_SW_PAGE_FAULTS_MAJ:
+       case PERF_COUNT_SW_CONTEXT_SWITCHES:
+       case PERF_COUNT_SW_CPU_MIGRATIONS:
                pmu = &perf_ops_generic;
                break;
        }
@@ -3447,10 +3558,11 @@ perf_counter_alloc(struct perf_counter_attr *attr,
        pmu = NULL;
 
        hwc = &counter->hw;
+       hwc->sample_period = attr->sample_period;
        if (attr->freq && attr->sample_freq)
-               hwc->sample_period = div64_u64(TICK_NSEC, attr->sample_freq);
-       else
-               hwc->sample_period = attr->sample_period;
+               hwc->sample_period = 1;
+
+       atomic64_set(&hwc->period_left, hwc->sample_period);
 
        /*
         * we currently do not support PERF_SAMPLE_GROUP on inherited counters
@@ -3458,13 +3570,10 @@ perf_counter_alloc(struct perf_counter_attr *attr,
        if (attr->inherit && (attr->sample_type & PERF_SAMPLE_GROUP))
                goto done;
 
-       if (perf_event_raw(attr)) {
-               pmu = hw_perf_counter_init(counter);
-               goto done;
-       }
-
-       switch (perf_event_type(attr)) {
+       switch (attr->type) {
+       case PERF_TYPE_RAW:
        case PERF_TYPE_HARDWARE:
+       case PERF_TYPE_HW_CACHE:
                pmu = hw_perf_counter_init(counter);
                break;
 
@@ -3475,6 +3584,9 @@ perf_counter_alloc(struct perf_counter_attr *attr,
        case PERF_TYPE_TRACEPOINT:
                pmu = tp_perf_counter_init(counter);
                break;
+
+       default:
+               break;
        }
 done:
        err = 0;
@@ -3501,6 +3613,85 @@ done:
        return counter;
 }
 
+static int perf_copy_attr(struct perf_counter_attr __user *uattr,
+                         struct perf_counter_attr *attr)
+{
+       int ret;
+       u32 size;
+
+       if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
+               return -EFAULT;
+
+       /*
+        * zero the full structure, so that a short copy will be nice.
+        */
+       memset(attr, 0, sizeof(*attr));
+
+       ret = get_user(size, &uattr->size);
+       if (ret)
+               return ret;
+
+       if (size > PAGE_SIZE)   /* silly large */
+               goto err_size;
+
+       if (!size)              /* abi compat */
+               size = PERF_ATTR_SIZE_VER0;
+
+       if (size < PERF_ATTR_SIZE_VER0)
+               goto err_size;
+
+       /*
+        * If we're handed a bigger struct than we know of,
+        * ensure all the unknown bits are 0.
+        */
+       if (size > sizeof(*attr)) {
+               unsigned long val;
+               unsigned long __user *addr;
+               unsigned long __user *end;
+
+               addr = PTR_ALIGN((void __user *)uattr + sizeof(*attr),
+                               sizeof(unsigned long));
+               end  = PTR_ALIGN((void __user *)uattr + size,
+                               sizeof(unsigned long));
+
+               for (; addr < end; addr += sizeof(unsigned long)) {
+                       ret = get_user(val, addr);
+                       if (ret)
+                               return ret;
+                       if (val)
+                               goto err_size;
+               }
+       }
+
+       ret = copy_from_user(attr, uattr, size);
+       if (ret)
+               return -EFAULT;
+
+       /*
+        * If the type exists, the corresponding creation will verify
+        * the attr->config.
+        */
+       if (attr->type >= PERF_TYPE_MAX)
+               return -EINVAL;
+
+       if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3)
+               return -EINVAL;
+
+       if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
+               return -EINVAL;
+
+       if (attr->read_format & ~(PERF_FORMAT_MAX-1))
+               return -EINVAL;
+
+out:
+       return ret;
+
+err_size:
+       put_user(sizeof(*attr), &uattr->size);
+       ret = -E2BIG;
+       goto out;
+}
+
 /**
  * sys_perf_counter_open - open a performance counter, associate it to a task/cpu
  *
@@ -3510,7 +3701,7 @@ done:
  * @group_fd:          group leader counter fd
  */
 SYSCALL_DEFINE5(perf_counter_open,
-               const struct perf_counter_attr __user *, attr_uptr,
+               struct perf_counter_attr __user *, attr_uptr,
                pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
 {
        struct perf_counter *counter, *group_leader;
@@ -3526,8 +3717,19 @@ SYSCALL_DEFINE5(perf_counter_open,
        if (flags)
                return -EINVAL;
 
-       if (copy_from_user(&attr, attr_uptr, sizeof(attr)) != 0)
-               return -EFAULT;
+       ret = perf_copy_attr(attr_uptr, &attr);
+       if (ret)
+               return ret;
+
+       if (!attr.exclude_kernel) {
+               if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
+                       return -EACCES;
+       }
+
+       if (attr.freq) {
+               if (attr.sample_freq > sysctl_perf_counter_sample_rate)
+                       return -EINVAL;
+       }
 
        /*
         * Get the target context (task or percpu):
@@ -3650,6 +3852,9 @@ inherit_counter(struct perf_counter *parent_counter,
        else
                child_counter->state = PERF_COUNTER_STATE_OFF;
 
+       if (parent_counter->attr.freq)
+               child_counter->hw.sample_period = parent_counter->hw.sample_period;
+
        /*
         * Link it up in the child's context:
         */
@@ -3796,7 +4001,18 @@ void perf_counter_exit_task(struct task_struct *child)
        spin_unlock(&child_ctx->lock);
        local_irq_restore(flags);
 
-       mutex_lock(&child_ctx->mutex);
+       /*
+        * We can recurse on the same lock type through:
+        *
+        *   __perf_counter_exit_task()
+        *     sync_child_counter()
+        *       fput(parent_counter->filp)
+        *         perf_release()
+        *           mutex_lock(&ctx->mutex)
+        *
+        * But since its the parent context it won't be the same instance.
+        */
+       mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING);
 
 again:
        list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list,