s390/cpum_sf: Filter perf events based event->attr.exclude_* settings

Introduce the perf_exclude_event() function to filter perf samples
according to event->attr.exclude_* settings.   During event initialization,
reset event exclude settings that are not supported.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 35 insertions, 1 deletions

diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index d611facae599..28fa2f235158 100644
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -723,10 +723,19 @@ static int cpumsf_pmu_event_init(struct perf_event *event)
                 return -ENOENT;
         }
 
+        /* Check online status of the CPU to which the event is pinned */
         if (event->cpu >= nr_cpumask_bits ||
             (event->cpu >= 0 && !cpu_online(event->cpu)))
                 return -ENODEV;
 
+        /* Force reset of idle/hv excludes regardless of what the
+         * user requested.
+         */
+        if (event->attr.exclude_hv)
+                event->attr.exclude_hv = 0;
+        if (event->attr.exclude_idle)
+                event->attr.exclude_idle = 0;
+
         err = __hw_perf_event_init(event);
         if (unlikely(err))
                 if (event->destroy)
@@ -824,6 +833,29 @@ static void cpumsf_pmu_disable(struct pmu *pmu)
         cpuhw->flags &= ~PMU_F_ENABLED;
 }
 
+/* perf_exclude_event() - Filter event
+ * @event:      The perf event
+ * @regs:       pt_regs structure
+ * @sde_regs:   Sample-data-entry (sde) regs structure
+ *
+ * Filter perf events according to their exclude specification.
+ *
+ * Return non-zero if the event shall be excluded.
+ */
+static int perf_exclude_event(struct perf_event *event, struct pt_regs *regs,
+                              struct perf_sf_sde_regs *sde_regs)
+{
+        if (event->attr.exclude_user && user_mode(regs))
+                return 1;
+        if (event->attr.exclude_kernel && !user_mode(regs))
+                return 1;
+        if (event->attr.exclude_guest && sde_regs->in_guest)
+                return 1;
+        if (event->attr.exclude_host && !sde_regs->in_guest)
+                return 1;
+        return 0;
+}
+
 /* perf_push_sample() - Push samples to perf
  * @event:      The perf event
  * @sample:     Hardware sample data
@@ -894,12 +926,14 @@ static int perf_push_sample(struct perf_event *event,
                 sde_regs->in_guest = 1;
 
         overflow = 0;
+        if (perf_exclude_event(event, &regs, sde_regs))
+                goto out;
         if (perf_event_overflow(event, &data, &regs)) {
                 overflow = 1;
                 event->pmu->stop(event, 0);
         }
         perf_event_update_userpage(event);
-
+out:
         return overflow;
 }