1 files changed, 74 insertions, 3 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index bb1a7c36e794..c40c2cac2d8e 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -327,6 +327,11 @@ static inline u64 perf_clock(void)
         return local_clock();
 }
 
+static inline u64 perf_event_clock(struct perf_event *event)
+{
+        return event->clock();
+}
+
 static inline struct perf_cpu_context *
 __get_cpu_context(struct perf_event_context *ctx)
 {
@@ -4762,7 +4767,7 @@ static void __perf_event_header__init_id(struct perf_event_header *header,
         }
 
         if (sample_type & PERF_SAMPLE_TIME)
-                data->time = perf_clock();
+                data->time = perf_event_clock(event);
 
         if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER))
                 data->id = primary_event_id(event);
@@ -5340,6 +5345,8 @@ static void perf_event_task_output(struct perf_event *event,
         task_event->event_id.tid = perf_event_tid(event, task);
         task_event->event_id.ptid = perf_event_tid(event, current);
 
+        task_event->event_id.time = perf_event_clock(event);
+
         perf_output_put(&handle, task_event->event_id);
 
         perf_event__output_id_sample(event, &handle, &sample);
@@ -5373,7 +5380,7 @@ static void perf_event_task(struct task_struct *task,
                         /* .ppid */
                         /* .tid  */
                         /* .ptid */
-                        .time = perf_clock(),
+                        /* .time */
                 },
         };
 
@@ -5749,7 +5756,7 @@ static void perf_log_throttle(struct perf_event *event, int enable)
                         .misc = 0,
                         .size = sizeof(throttle_event),
                 },
-                .time           = perf_clock(),
+                .time           = perf_event_clock(event),
                 .id             = primary_event_id(event),
                 .stream_id      = event->id,
         };
@@ -6293,6 +6300,8 @@ static int perf_swevent_init(struct perf_event *event)
 static struct pmu perf_swevent = {
         .task_ctx_nr    = perf_sw_context,
 
+        .capabilities   = PERF_PMU_CAP_NO_NMI,
+
         .event_init     = perf_swevent_init,
         .add            = perf_swevent_add,
         .del            = perf_swevent_del,
@@ -6636,6 +6645,8 @@ static int cpu_clock_event_init(struct perf_event *event)
 static struct pmu perf_cpu_clock = {
         .task_ctx_nr    = perf_sw_context,
 
+        .capabilities   = PERF_PMU_CAP_NO_NMI,
+
         .event_init     = cpu_clock_event_init,
         .add            = cpu_clock_event_add,
         .del            = cpu_clock_event_del,
@@ -6715,6 +6726,8 @@ static int task_clock_event_init(struct perf_event *event)
 static struct pmu perf_task_clock = {
         .task_ctx_nr    = perf_sw_context,
 
+        .capabilities   = PERF_PMU_CAP_NO_NMI,
+
         .event_init     = task_clock_event_init,
         .add            = task_clock_event_add,
         .del            = task_clock_event_del,
@@ -7200,6 +7213,10 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
                 event->hw.target = task;
         }
 
+        event->clock = &local_clock;
+        if (parent_event)
+                event->clock = parent_event->clock;
+
         if (!overflow_handler && parent_event) {
                 overflow_handler = parent_event->overflow_handler;
                 context = parent_event->overflow_handler_context;
@@ -7422,6 +7439,12 @@ perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
         if (output_event->cpu == -1 && output_event->ctx != event->ctx)
                 goto out;
 
+        /*
+         * Mixing clocks in the same buffer is trouble you don't need.
+         */
+        if (output_event->clock != event->clock)
+                goto out;
+
 set:
         mutex_lock(&event->mmap_mutex);
         /* Can't redirect output if we've got an active mmap() */
@@ -7454,6 +7477,43 @@ static void mutex_lock_double(struct mutex *a, struct mutex *b)
         mutex_lock_nested(b, SINGLE_DEPTH_NESTING);
 }
 
+static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
+{
+        bool nmi_safe = false;
+
+        switch (clk_id) {
+        case CLOCK_MONOTONIC:
+                event->clock = &ktime_get_mono_fast_ns;
+                nmi_safe = true;
+                break;
+
+        case CLOCK_MONOTONIC_RAW:
+                event->clock = &ktime_get_raw_fast_ns;
+                nmi_safe = true;
+                break;
+
+        case CLOCK_REALTIME:
+                event->clock = &ktime_get_real_ns;
+                break;
+
+        case CLOCK_BOOTTIME:
+                event->clock = &ktime_get_boot_ns;
+                break;
+
+        case CLOCK_TAI:
+                event->clock = &ktime_get_tai_ns;
+                break;
+
+        default:
+                return -EINVAL;
+        }
+
+        if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI))
+                return -EINVAL;
+
+        return 0;
+}
+
 /**
  * sys_perf_event_open - open a performance event, associate it to a task/cpu
  *
@@ -7569,6 +7629,12 @@ SYSCALL_DEFINE5(perf_event_open,
          */
         pmu = event->pmu;
 
+        if (attr.use_clockid) {
+                err = perf_event_set_clock(event, attr.clockid);
+                if (err)
+                        goto err_alloc;
+        }
+
         if (group_leader &&
             (is_software_event(event) != is_software_event(group_leader))) {
                 if (is_software_event(event)) {
@@ -7618,6 +7684,11 @@ SYSCALL_DEFINE5(perf_event_open,
                  */
                 if (group_leader->group_leader != group_leader)
                         goto err_context;
+
+                /* All events in a group should have the same clock */
+                if (group_leader->clock != event->clock)
+                        goto err_context;
+
                 /*
                  * Do not allow to attach to a group in a different
                  * task or CPU context: