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-rw-r--r--kernel/events/core.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index e1459df73043..81e6d80cb219 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -387,6 +387,7 @@ static atomic_t nr_freq_events __read_mostly;
static atomic_t nr_switch_events __read_mostly;
static atomic_t nr_ksymbol_events __read_mostly;
static atomic_t nr_bpf_events __read_mostly;
+static atomic_t nr_cgroup_events __read_mostly;
static LIST_HEAD(pmus);
static DEFINE_MUTEX(pmus_lock);
@@ -1861,6 +1862,9 @@ static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
if (sample_type & PERF_SAMPLE_PHYS_ADDR)
size += sizeof(data->phys_addr);
+ if (sample_type & PERF_SAMPLE_CGROUP)
+ size += sizeof(data->cgroup);
+
event->header_size = size;
}
@@ -4608,6 +4612,8 @@ static void unaccount_event(struct perf_event *event)
atomic_dec(&nr_comm_events);
if (event->attr.namespaces)
atomic_dec(&nr_namespaces_events);
+ if (event->attr.cgroup)
+ atomic_dec(&nr_cgroup_events);
if (event->attr.task)
atomic_dec(&nr_task_events);
if (event->attr.freq)
@@ -6864,6 +6870,9 @@ void perf_output_sample(struct perf_output_handle *handle,
if (sample_type & PERF_SAMPLE_PHYS_ADDR)
perf_output_put(handle, data->phys_addr);
+ if (sample_type & PERF_SAMPLE_CGROUP)
+ perf_output_put(handle, data->cgroup);
+
if (sample_type & PERF_SAMPLE_AUX) {
perf_output_put(handle, data->aux_size);
@@ -7063,6 +7072,16 @@ void perf_prepare_sample(struct perf_event_header *header,
if (sample_type & PERF_SAMPLE_PHYS_ADDR)
data->phys_addr = perf_virt_to_phys(data->addr);
+#ifdef CONFIG_CGROUP_PERF
+ if (sample_type & PERF_SAMPLE_CGROUP) {
+ struct cgroup *cgrp;
+
+ /* protected by RCU */
+ cgrp = task_css_check(current, perf_event_cgrp_id, 1)->cgroup;
+ data->cgroup = cgroup_id(cgrp);
+ }
+#endif
+
if (sample_type & PERF_SAMPLE_AUX) {
u64 size;
@@ -7736,6 +7755,105 @@ void perf_event_namespaces(struct task_struct *task)
}
/*
+ * cgroup tracking
+ */
+#ifdef CONFIG_CGROUP_PERF
+
+struct perf_cgroup_event {
+ char *path;
+ int path_size;
+ struct {
+ struct perf_event_header header;
+ u64 id;
+ char path[];
+ } event_id;
+};
+
+static int perf_event_cgroup_match(struct perf_event *event)
+{
+ return event->attr.cgroup;
+}
+
+static void perf_event_cgroup_output(struct perf_event *event, void *data)
+{
+ struct perf_cgroup_event *cgroup_event = data;
+ struct perf_output_handle handle;
+ struct perf_sample_data sample;
+ u16 header_size = cgroup_event->event_id.header.size;
+ int ret;
+
+ if (!perf_event_cgroup_match(event))
+ return;
+
+ perf_event_header__init_id(&cgroup_event->event_id.header,
+ &sample, event);
+ ret = perf_output_begin(&handle, event,
+ cgroup_event->event_id.header.size);
+ if (ret)
+ goto out;
+
+ perf_output_put(&handle, cgroup_event->event_id);
+ __output_copy(&handle, cgroup_event->path, cgroup_event->path_size);
+
+ perf_event__output_id_sample(event, &handle, &sample);
+
+ perf_output_end(&handle);
+out:
+ cgroup_event->event_id.header.size = header_size;
+}
+
+static void perf_event_cgroup(struct cgroup *cgrp)
+{
+ struct perf_cgroup_event cgroup_event;
+ char path_enomem[16] = "//enomem";
+ char *pathname;
+ size_t size;
+
+ if (!atomic_read(&nr_cgroup_events))
+ return;
+
+ cgroup_event = (struct perf_cgroup_event){
+ .event_id = {
+ .header = {
+ .type = PERF_RECORD_CGROUP,
+ .misc = 0,
+ .size = sizeof(cgroup_event.event_id),
+ },
+ .id = cgroup_id(cgrp),
+ },
+ };
+
+ pathname = kmalloc(PATH_MAX, GFP_KERNEL);
+ if (pathname == NULL) {
+ cgroup_event.path = path_enomem;
+ } else {
+ /* just to be sure to have enough space for alignment */
+ cgroup_path(cgrp, pathname, PATH_MAX - sizeof(u64));
+ cgroup_event.path = pathname;
+ }
+
+ /*
+ * Since our buffer works in 8 byte units we need to align our string
+ * size to a multiple of 8. However, we must guarantee the tail end is
+ * zero'd out to avoid leaking random bits to userspace.
+ */
+ size = strlen(cgroup_event.path) + 1;
+ while (!IS_ALIGNED(size, sizeof(u64)))
+ cgroup_event.path[size++] = '\0';
+
+ cgroup_event.event_id.header.size += size;
+ cgroup_event.path_size = size;
+
+ perf_iterate_sb(perf_event_cgroup_output,
+ &cgroup_event,
+ NULL);
+
+ kfree(pathname);
+}
+
+#endif
+
+/*
* mmap tracking
*/
@@ -10778,6 +10896,8 @@ static void account_event(struct perf_event *event)
atomic_inc(&nr_comm_events);
if (event->attr.namespaces)
atomic_inc(&nr_namespaces_events);
+ if (event->attr.cgroup)
+ atomic_inc(&nr_cgroup_events);
if (event->attr.task)
atomic_inc(&nr_task_events);
if (event->attr.freq)
@@ -11157,6 +11277,12 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
if (attr->sample_type & PERF_SAMPLE_REGS_INTR)
ret = perf_reg_validate(attr->sample_regs_intr);
+
+#ifndef CONFIG_CGROUP_PERF
+ if (attr->sample_type & PERF_SAMPLE_CGROUP)
+ return -EINVAL;
+#endif
+
out:
return ret;
@@ -12754,6 +12880,12 @@ static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
kfree(jc);
}
+static int perf_cgroup_css_online(struct cgroup_subsys_state *css)
+{
+ perf_event_cgroup(css->cgroup);
+ return 0;
+}
+
static int __perf_cgroup_move(void *info)
{
struct task_struct *task = info;
@@ -12775,6 +12907,7 @@ static void perf_cgroup_attach(struct cgroup_taskset *tset)
struct cgroup_subsys perf_event_cgrp_subsys = {
.css_alloc = perf_cgroup_css_alloc,
.css_free = perf_cgroup_css_free,
+ .css_online = perf_cgroup_css_online,
.attach = perf_cgroup_attach,
/*
* Implicitly enable on dfl hierarchy so that perf events can