summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--include/linux/perf_event.h10
-rw-r--r--kernel/events/core.c77
2 files changed, 51 insertions, 36 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index d5628a7b5eaa..bf4f346d6d70 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -295,6 +295,8 @@ struct perf_event_pmu_context;
struct perf_output_handle;
+#define PMU_NULL_DEV ((void *)(~0UL))
+
/**
* struct pmu - generic performance monitoring unit
*/
@@ -827,6 +829,14 @@ struct perf_event {
void *security;
#endif
struct list_head sb_list;
+
+ /*
+ * Certain events gets forwarded to another pmu internally by over-
+ * writing kernel copy of event->attr.type without user being aware
+ * of it. event->orig_type contains original 'type' requested by
+ * user.
+ */
+ __u32 orig_type;
#endif /* CONFIG_PERF_EVENTS */
};
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 68baa8194d9f..c01bbe93e291 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6647,7 +6647,7 @@ static void perf_sigtrap(struct perf_event *event)
return;
send_sig_perf((void __user *)event->pending_addr,
- event->attr.type, event->attr.sig_data);
+ event->orig_type, event->attr.sig_data);
}
/*
@@ -9951,6 +9951,9 @@ static void sw_perf_event_destroy(struct perf_event *event)
swevent_hlist_put();
}
+static struct pmu perf_cpu_clock; /* fwd declaration */
+static struct pmu perf_task_clock;
+
static int perf_swevent_init(struct perf_event *event)
{
u64 event_id = event->attr.config;
@@ -9966,7 +9969,10 @@ static int perf_swevent_init(struct perf_event *event)
switch (event_id) {
case PERF_COUNT_SW_CPU_CLOCK:
+ event->attr.type = perf_cpu_clock.type;
+ return -ENOENT;
case PERF_COUNT_SW_TASK_CLOCK:
+ event->attr.type = perf_task_clock.type;
return -ENOENT;
default:
@@ -11086,7 +11092,7 @@ static void cpu_clock_event_read(struct perf_event *event)
static int cpu_clock_event_init(struct perf_event *event)
{
- if (event->attr.type != PERF_TYPE_SOFTWARE)
+ if (event->attr.type != perf_cpu_clock.type)
return -ENOENT;
if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
@@ -11107,6 +11113,7 @@ static struct pmu perf_cpu_clock = {
.task_ctx_nr = perf_sw_context,
.capabilities = PERF_PMU_CAP_NO_NMI,
+ .dev = PMU_NULL_DEV,
.event_init = cpu_clock_event_init,
.add = cpu_clock_event_add,
@@ -11167,7 +11174,7 @@ static void task_clock_event_read(struct perf_event *event)
static int task_clock_event_init(struct perf_event *event)
{
- if (event->attr.type != PERF_TYPE_SOFTWARE)
+ if (event->attr.type != perf_task_clock.type)
return -ENOENT;
if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
@@ -11188,6 +11195,7 @@ static struct pmu perf_task_clock = {
.task_ctx_nr = perf_sw_context,
.capabilities = PERF_PMU_CAP_NO_NMI,
+ .dev = PMU_NULL_DEV,
.event_init = task_clock_event_init,
.add = task_clock_event_add,
@@ -11415,31 +11423,31 @@ int perf_pmu_register(struct pmu *pmu, const char *name, int type)
goto unlock;
pmu->type = -1;
- if (!name)
- goto skip_type;
+ if (WARN_ONCE(!name, "Can not register anonymous pmu.\n")) {
+ ret = -EINVAL;
+ goto free_pdc;
+ }
+
pmu->name = name;
- if (type != PERF_TYPE_SOFTWARE) {
- if (type >= 0)
- max = type;
+ if (type >= 0)
+ max = type;
- ret = idr_alloc(&pmu_idr, pmu, max, 0, GFP_KERNEL);
- if (ret < 0)
- goto free_pdc;
+ ret = idr_alloc(&pmu_idr, pmu, max, 0, GFP_KERNEL);
+ if (ret < 0)
+ goto free_pdc;
- WARN_ON(type >= 0 && ret != type);
+ WARN_ON(type >= 0 && ret != type);
- type = ret;
- }
+ type = ret;
pmu->type = type;
- if (pmu_bus_running) {
+ if (pmu_bus_running && !pmu->dev) {
ret = pmu_dev_alloc(pmu);
if (ret)
goto free_idr;
}
-skip_type:
ret = -ENOMEM;
pmu->cpu_pmu_context = alloc_percpu(struct perf_cpu_pmu_context);
if (!pmu->cpu_pmu_context)
@@ -11481,16 +11489,7 @@ skip_type:
if (!pmu->event_idx)
pmu->event_idx = perf_event_idx_default;
- /*
- * Ensure the TYPE_SOFTWARE PMUs are at the head of the list,
- * since these cannot be in the IDR. This way the linear search
- * is fast, provided a valid software event is provided.
- */
- if (type == PERF_TYPE_SOFTWARE || !name)
- list_add_rcu(&pmu->entry, &pmus);
- else
- list_add_tail_rcu(&pmu->entry, &pmus);
-
+ list_add_rcu(&pmu->entry, &pmus);
atomic_set(&pmu->exclusive_cnt, 0);
ret = 0;
unlock:
@@ -11499,12 +11498,13 @@ unlock:
return ret;
free_dev:
- device_del(pmu->dev);
- put_device(pmu->dev);
+ if (pmu->dev && pmu->dev != PMU_NULL_DEV) {
+ device_del(pmu->dev);
+ put_device(pmu->dev);
+ }
free_idr:
- if (pmu->type != PERF_TYPE_SOFTWARE)
- idr_remove(&pmu_idr, pmu->type);
+ idr_remove(&pmu_idr, pmu->type);
free_pdc:
free_percpu(pmu->pmu_disable_count);
@@ -11525,9 +11525,8 @@ void perf_pmu_unregister(struct pmu *pmu)
synchronize_rcu();
free_percpu(pmu->pmu_disable_count);
- if (pmu->type != PERF_TYPE_SOFTWARE)
- idr_remove(&pmu_idr, pmu->type);
- if (pmu_bus_running) {
+ idr_remove(&pmu_idr, pmu->type);
+ if (pmu_bus_running && pmu->dev && pmu->dev != PMU_NULL_DEV) {
if (pmu->nr_addr_filters)
device_remove_file(pmu->dev, &dev_attr_nr_addr_filters);
device_del(pmu->dev);
@@ -11601,6 +11600,12 @@ static struct pmu *perf_init_event(struct perf_event *event)
idx = srcu_read_lock(&pmus_srcu);
+ /*
+ * Save original type before calling pmu->event_init() since certain
+ * pmus overwrites event->attr.type to forward event to another pmu.
+ */
+ event->orig_type = event->attr.type;
+
/* Try parent's PMU first: */
if (event->parent && event->parent->pmu) {
pmu = event->parent->pmu;
@@ -13640,8 +13645,8 @@ void __init perf_event_init(void)
perf_event_init_all_cpus();
init_srcu_struct(&pmus_srcu);
perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
- perf_pmu_register(&perf_cpu_clock, NULL, -1);
- perf_pmu_register(&perf_task_clock, NULL, -1);
+ perf_pmu_register(&perf_cpu_clock, "cpu_clock", -1);
+ perf_pmu_register(&perf_task_clock, "task_clock", -1);
perf_tp_register();
perf_event_init_cpu(smp_processor_id());
register_reboot_notifier(&perf_reboot_notifier);
@@ -13684,7 +13689,7 @@ static int __init perf_event_sysfs_init(void)
goto unlock;
list_for_each_entry(pmu, &pmus, entry) {
- if (!pmu->name || pmu->type < 0)
+ if (pmu->dev)
continue;
ret = pmu_dev_alloc(pmu);
generated by cgit (git 2.34.1) at 2024-05-18 20:23:51 +0000