PERF_FLAG_FD_OUTPUT |\
PERF_FLAG_PID_CGROUP)
+/*
+ * branch priv levels that need permission checks
+ */
+#define PERF_SAMPLE_BRANCH_PERM_PLM \
+ (PERF_SAMPLE_BRANCH_KERNEL |\
+ PERF_SAMPLE_BRANCH_HV)
+
enum event_type_t {
EVENT_FLEXIBLE = 0x1,
EVENT_PINNED = 0x2,
* perf_sched_events : >0 events exist
* perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
*/
-struct jump_label_key_deferred perf_sched_events __read_mostly;
+struct static_key_deferred perf_sched_events __read_mostly;
static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
+static DEFINE_PER_CPU(atomic_t, perf_branch_stack_events);
static atomic_t nr_mmap_events __read_mostly;
static atomic_t nr_comm_events __read_mostly;
if (is_cgroup_event(event))
ctx->nr_cgroups++;
+ if (has_branch_stack(event))
+ ctx->nr_branch_stack++;
+
list_add_rcu(&event->event_entry, &ctx->event_list);
if (!ctx->nr_events)
perf_pmu_rotate_start(ctx->pmu);
cpuctx->cgrp = NULL;
}
+ if (has_branch_stack(event))
+ ctx->nr_branch_stack--;
+
ctx->nr_events--;
if (event->attr.inherit_stat)
ctx->nr_stat--;
perf_pmu_rotate_start(ctx->pmu);
}
+/*
+ * When sampling the branck stack in system-wide, it may be necessary
+ * to flush the stack on context switch. This happens when the branch
+ * stack does not tag its entries with the pid of the current task.
+ * Otherwise it becomes impossible to associate a branch entry with a
+ * task. This ambiguity is more likely to appear when the branch stack
+ * supports priv level filtering and the user sets it to monitor only
+ * at the user level (which could be a useful measurement in system-wide
+ * mode). In that case, the risk is high of having a branch stack with
+ * branch from multiple tasks. Flushing may mean dropping the existing
+ * entries or stashing them somewhere in the PMU specific code layer.
+ *
+ * This function provides the context switch callback to the lower code
+ * layer. It is invoked ONLY when there is at least one system-wide context
+ * with at least one active event using taken branch sampling.
+ */
+static void perf_branch_stack_sched_in(struct task_struct *prev,
+ struct task_struct *task)
+{
+ struct perf_cpu_context *cpuctx;
+ struct pmu *pmu;
+ unsigned long flags;
+
+ /* no need to flush branch stack if not changing task */
+ if (prev == task)
+ return;
+
+ local_irq_save(flags);
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(pmu, &pmus, entry) {
+ cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+
+ /*
+ * check if the context has at least one
+ * event using PERF_SAMPLE_BRANCH_STACK
+ */
+ if (cpuctx->ctx.nr_branch_stack > 0
+ && pmu->flush_branch_stack) {
+
+ pmu = cpuctx->ctx.pmu;
+
+ perf_ctx_lock(cpuctx, cpuctx->task_ctx);
+
+ perf_pmu_disable(pmu);
+
+ pmu->flush_branch_stack();
+
+ perf_pmu_enable(pmu);
+
+ perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
+ }
+ }
+
+ rcu_read_unlock();
+
+ local_irq_restore(flags);
+}
+
/*
* Called from scheduler to add the events of the current task
* with interrupts disabled.
*/
if (atomic_read(&__get_cpu_var(perf_cgroup_events)))
perf_cgroup_sched_in(prev, task);
+
+ /* check for system-wide branch_stack events */
+ if (atomic_read(&__get_cpu_var(perf_branch_stack_events)))
+ perf_branch_stack_sched_in(prev, task);
}
static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
if (!event->parent) {
if (event->attach_state & PERF_ATTACH_TASK)
- jump_label_dec_deferred(&perf_sched_events);
+ static_key_slow_dec_deferred(&perf_sched_events);
if (event->attr.mmap || event->attr.mmap_data)
atomic_dec(&nr_mmap_events);
if (event->attr.comm)
put_callchain_buffers();
if (is_cgroup_event(event)) {
atomic_dec(&per_cpu(perf_cgroup_events, event->cpu));
- jump_label_dec_deferred(&perf_sched_events);
+ static_key_slow_dec_deferred(&perf_sched_events);
+ }
+
+ if (has_branch_stack(event)) {
+ static_key_slow_dec_deferred(&perf_sched_events);
+ /* is system-wide event */
+ if (!(event->attach_state & PERF_ATTACH_TASK))
+ atomic_dec(&per_cpu(perf_branch_stack_events,
+ event->cpu));
}
}
return 0;
}
-#ifndef PERF_EVENT_INDEX_OFFSET
-# define PERF_EVENT_INDEX_OFFSET 0
-#endif
-
static int perf_event_index(struct perf_event *event)
{
if (event->hw.state & PERF_HES_STOPPED)
if (event->state != PERF_EVENT_STATE_ACTIVE)
return 0;
- return event->hw.idx + 1 - PERF_EVENT_INDEX_OFFSET;
+ return event->pmu->event_idx(event);
}
static void calc_timer_values(struct perf_event *event,
+ u64 *now,
u64 *enabled,
u64 *running)
{
- u64 now, ctx_time;
+ u64 ctx_time;
- now = perf_clock();
- ctx_time = event->shadow_ctx_time + now;
+ *now = perf_clock();
+ ctx_time = event->shadow_ctx_time + *now;
*enabled = ctx_time - event->tstamp_enabled;
*running = ctx_time - event->tstamp_running;
}
+void __weak perf_update_user_clock(struct perf_event_mmap_page *userpg, u64 now)
+{
+}
+
/*
* Callers need to ensure there can be no nesting of this function, otherwise
* the seqlock logic goes bad. We can not serialize this because the arch
{
struct perf_event_mmap_page *userpg;
struct ring_buffer *rb;
- u64 enabled, running;
+ u64 enabled, running, now;
rcu_read_lock();
/*
* because of locking issue as we can be called in
* NMI context
*/
- calc_timer_values(event, &enabled, &running);
+ calc_timer_values(event, &now, &enabled, &running);
rb = rcu_dereference(event->rb);
if (!rb)
goto unlock;
barrier();
userpg->index = perf_event_index(event);
userpg->offset = perf_event_count(event);
- if (event->state == PERF_EVENT_STATE_ACTIVE)
+ if (userpg->index)
userpg->offset -= local64_read(&event->hw.prev_count);
userpg->time_enabled = enabled +
userpg->time_running = running +
atomic64_read(&event->child_total_time_running);
+ perf_update_user_clock(userpg, now);
+
barrier();
++userpg->lock;
preempt_enable();
event->mmap_user = get_current_user();
vma->vm_mm->pinned_vm += event->mmap_locked;
+ perf_event_update_userpage(event);
+
unlock:
if (!ret)
atomic_inc(&event->mmap_count);
static void perf_output_read(struct perf_output_handle *handle,
struct perf_event *event)
{
- u64 enabled = 0, running = 0;
+ u64 enabled = 0, running = 0, now;
u64 read_format = event->attr.read_format;
/*
* NMI context
*/
if (read_format & PERF_FORMAT_TOTAL_TIMES)
- calc_timer_values(event, &enabled, &running);
+ calc_timer_values(event, &now, &enabled, &running);
if (event->attr.read_format & PERF_FORMAT_GROUP)
perf_output_read_group(handle, event, enabled, running);
}
}
}
+
+ if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
+ if (data->br_stack) {
+ size_t size;
+
+ size = data->br_stack->nr
+ * sizeof(struct perf_branch_entry);
+
+ perf_output_put(handle, data->br_stack->nr);
+ perf_output_copy(handle, data->br_stack->entries, size);
+ } else {
+ /*
+ * we always store at least the value of nr
+ */
+ u64 nr = 0;
+ perf_output_put(handle, nr);
+ }
+ }
}
void perf_prepare_sample(struct perf_event_header *header,
WARN_ON_ONCE(size & (sizeof(u64)-1));
header->size += size;
}
+
+ if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
+ int size = sizeof(u64); /* nr */
+ if (data->br_stack) {
+ size += data->br_stack->nr
+ * sizeof(struct perf_branch_entry);
+ }
+ header->size += size;
+ }
}
static void perf_event_output(struct perf_event *event,
return err;
}
-struct jump_label_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
+struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
static void sw_perf_event_destroy(struct perf_event *event)
{
WARN_ON(event->parent);
- jump_label_dec(&perf_swevent_enabled[event_id]);
+ static_key_slow_dec(&perf_swevent_enabled[event_id]);
swevent_hlist_put(event);
}
if (event->attr.type != PERF_TYPE_SOFTWARE)
return -ENOENT;
+ /*
+ * no branch sampling for software events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
switch (event_id) {
case PERF_COUNT_SW_CPU_CLOCK:
case PERF_COUNT_SW_TASK_CLOCK:
if (err)
return err;
- jump_label_inc(&perf_swevent_enabled[event_id]);
+ static_key_slow_inc(&perf_swevent_enabled[event_id]);
event->destroy = sw_perf_event_destroy;
}
return 0;
}
+static int perf_swevent_event_idx(struct perf_event *event)
+{
+ return 0;
+}
+
static struct pmu perf_swevent = {
.task_ctx_nr = perf_sw_context,
.start = perf_swevent_start,
.stop = perf_swevent_stop,
.read = perf_swevent_read,
+
+ .event_idx = perf_swevent_event_idx,
};
#ifdef CONFIG_EVENT_TRACING
if (event->attr.type != PERF_TYPE_TRACEPOINT)
return -ENOENT;
+ /*
+ * no branch sampling for tracepoint events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
err = perf_trace_init(event);
if (err)
return err;
.start = perf_swevent_start,
.stop = perf_swevent_stop,
.read = perf_swevent_read,
+
+ .event_idx = perf_swevent_event_idx,
};
static inline void perf_tp_register(void)
if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
return -ENOENT;
+ /*
+ * no branch sampling for software events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
perf_swevent_init_hrtimer(event);
return 0;
.start = cpu_clock_event_start,
.stop = cpu_clock_event_stop,
.read = cpu_clock_event_read,
+
+ .event_idx = perf_swevent_event_idx,
};
/*
if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
return -ENOENT;
+ /*
+ * no branch sampling for software events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
perf_swevent_init_hrtimer(event);
return 0;
.start = task_clock_event_start,
.stop = task_clock_event_stop,
.read = task_clock_event_read,
+
+ .event_idx = perf_swevent_event_idx,
};
static void perf_pmu_nop_void(struct pmu *pmu)
perf_pmu_enable(pmu);
}
+static int perf_event_idx_default(struct perf_event *event)
+{
+ return event->hw.idx + 1;
+}
+
/*
* Ensures all contexts with the same task_ctx_nr have the same
* pmu_cpu_context too.
if (!pmu->dev)
goto out;
+ pmu->dev->groups = pmu->attr_groups;
device_initialize(pmu->dev);
ret = dev_set_name(pmu->dev, "%s", pmu->name);
if (ret)
pmu->pmu_disable = perf_pmu_nop_void;
}
+ if (!pmu->event_idx)
+ pmu->event_idx = perf_event_idx_default;
+
list_add_rcu(&pmu->entry, &pmus);
ret = 0;
unlock:
if (!event->parent) {
if (event->attach_state & PERF_ATTACH_TASK)
- jump_label_inc(&perf_sched_events.key);
+ static_key_slow_inc(&perf_sched_events.key);
if (event->attr.mmap || event->attr.mmap_data)
atomic_inc(&nr_mmap_events);
if (event->attr.comm)
return ERR_PTR(err);
}
}
+ if (has_branch_stack(event)) {
+ static_key_slow_inc(&perf_sched_events.key);
+ if (!(event->attach_state & PERF_ATTACH_TASK))
+ atomic_inc(&per_cpu(perf_branch_stack_events,
+ event->cpu));
+ }
}
return event;
if (attr->read_format & ~(PERF_FORMAT_MAX-1))
return -EINVAL;
+ if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
+ u64 mask = attr->branch_sample_type;
+
+ /* only using defined bits */
+ if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1))
+ return -EINVAL;
+
+ /* at least one branch bit must be set */
+ if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL))
+ return -EINVAL;
+
+ /* kernel level capture: check permissions */
+ if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM)
+ && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ /* propagate priv level, when not set for branch */
+ if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) {
+
+ /* exclude_kernel checked on syscall entry */
+ if (!attr->exclude_kernel)
+ mask |= PERF_SAMPLE_BRANCH_KERNEL;
+
+ if (!attr->exclude_user)
+ mask |= PERF_SAMPLE_BRANCH_USER;
+
+ if (!attr->exclude_hv)
+ mask |= PERF_SAMPLE_BRANCH_HV;
+ /*
+ * adjust user setting (for HW filter setup)
+ */
+ attr->branch_sample_type = mask;
+ }
+ }
out:
return ret;
* - that may need work on context switch
*/
atomic_inc(&per_cpu(perf_cgroup_events, event->cpu));
- jump_label_inc(&perf_sched_events.key);
+ static_key_slow_inc(&perf_sched_events.key);
}
/*
device_initcall(perf_event_sysfs_init);
#ifdef CONFIG_CGROUP_PERF
-static struct cgroup_subsys_state *perf_cgroup_create(
- struct cgroup_subsys *ss, struct cgroup *cont)
+static struct cgroup_subsys_state *perf_cgroup_create(struct cgroup *cont)
{
struct perf_cgroup *jc;
return &jc->css;
}
-static void perf_cgroup_destroy(struct cgroup_subsys *ss,
- struct cgroup *cont)
+static void perf_cgroup_destroy(struct cgroup *cont)
{
struct perf_cgroup *jc;
jc = container_of(cgroup_subsys_state(cont, perf_subsys_id),
return 0;
}
-static void perf_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct cgroup_taskset *tset)
+static void perf_cgroup_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
{
struct task_struct *task;
task_function_call(task, __perf_cgroup_move, task);
}
-static void perf_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct cgroup *old_cgrp, struct task_struct *task)
+static void perf_cgroup_exit(struct cgroup *cgrp, struct cgroup *old_cgrp,
+ struct task_struct *task)
{
/*
* cgroup_exit() is called in the copy_process() failure path.
projects / ~andy / linux / blobdiff