diff options
Diffstat (limited to 'kernel/events/core.c')
-rw-r--r-- | kernel/events/core.c | 87 |
1 files changed, 65 insertions, 22 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 77f9e5d..ae16867 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3972,28 +3972,21 @@ static void perf_event_for_each(struct perf_event *event, perf_event_for_each_child(sibling, func); } -static int perf_event_period(struct perf_event *event, u64 __user *arg) -{ - struct perf_event_context *ctx = event->ctx; - int ret = 0, active; +struct period_event { + struct perf_event *event; u64 value; +}; - if (!is_sampling_event(event)) - return -EINVAL; - - if (copy_from_user(&value, arg, sizeof(value))) - return -EFAULT; - - if (!value) - return -EINVAL; +static int __perf_event_period(void *info) +{ + struct period_event *pe = info; + struct perf_event *event = pe->event; + struct perf_event_context *ctx = event->ctx; + u64 value = pe->value; + bool active; - raw_spin_lock_irq(&ctx->lock); + raw_spin_lock(&ctx->lock); if (event->attr.freq) { - if (value > sysctl_perf_event_sample_rate) { - ret = -EINVAL; - goto unlock; - } - event->attr.sample_freq = value; } else { event->attr.sample_period = value; @@ -4012,11 +4005,53 @@ static int perf_event_period(struct perf_event *event, u64 __user *arg) event->pmu->start(event, PERF_EF_RELOAD); perf_pmu_enable(ctx->pmu); } + raw_spin_unlock(&ctx->lock); -unlock: + return 0; +} + +static int perf_event_period(struct perf_event *event, u64 __user *arg) +{ + struct period_event pe = { .event = event, }; + struct perf_event_context *ctx = event->ctx; + struct task_struct *task; + u64 value; + + if (!is_sampling_event(event)) + return -EINVAL; + + if (copy_from_user(&value, arg, sizeof(value))) + return -EFAULT; + + if (!value) + return -EINVAL; + + if (event->attr.freq && value > sysctl_perf_event_sample_rate) + return -EINVAL; + + task = ctx->task; + pe.value = value; + + if (!task) { + cpu_function_call(event->cpu, __perf_event_period, &pe); + return 0; + } + +retry: + if (!task_function_call(task, __perf_event_period, &pe)) + return 0; + + raw_spin_lock_irq(&ctx->lock); + if (ctx->is_active) { + raw_spin_unlock_irq(&ctx->lock); + task = ctx->task; + goto retry; + } + + __perf_event_period(&pe); raw_spin_unlock_irq(&ctx->lock); - return ret; + return 0; } static const struct file_operations perf_fops; @@ -4754,12 +4789,20 @@ static const struct file_operations perf_fops = { * to user-space before waking everybody up. */ +static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) +{ + /* only the parent has fasync state */ + if (event->parent) + event = event->parent; + return &event->fasync; +} + void perf_event_wakeup(struct perf_event *event) { ring_buffer_wakeup(event); if (event->pending_kill) { - kill_fasync(&event->fasync, SIGIO, event->pending_kill); + kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); event->pending_kill = 0; } } @@ -6221,7 +6264,7 @@ static int __perf_event_overflow(struct perf_event *event, else perf_event_output(event, data, regs); - if (event->fasync && event->pending_kill) { + if (*perf_event_fasync(event) && event->pending_kill) { event->pending_wakeup = 1; irq_work_queue(&event->pending); } |