perf: Fix sibling iteration

Mark noticed that the change to sibling_list changed some iteration
semantics; because previously we used group_list as list entry,
sibling events would always have an empty sibling_list.

But because we now use sibling_list for both list head and list entry,
siblings will report as having siblings.

Fix this with a custom for_each_sibling_event() iterator.

Fixes: 8343aae66167 ("perf/core: Remove perf_event::group_entry")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: vincent.weaver@maine.edu
Cc: alexander.shishkin@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: alexey.budankov@linux.intel.com
Cc: valery.cherepennikov@intel.com
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: linux-tip-commits@vger.kernel.org
Cc: davidcc@google.com
Cc: kan.liang@intel.com
Cc: Dmitry.Prohorov@intel.com
Cc: jolsa@redhat.com
Link: https://lkml.kernel.org/r/20180315170129.GX4043@hirez.programming.kicks-ass.net

6 files changed, 9 insertions, 10 deletions

diff --git a/drivers/perf/arm_dsu_pmu.c b/drivers/perf/arm_dsu_pmu.c
index 660680d78147..660cb8ac886a 100644
--- a/drivers/perf/arm_dsu_pmu.c
+++ b/drivers/perf/arm_dsu_pmu.c
@@ -536,7 +536,7 @@ static bool dsu_pmu_validate_group(struct perf_event *event)
 	memset(fake_hw.used_mask, 0, sizeof(fake_hw.used_mask));
 	if (!dsu_pmu_validate_event(event->pmu, &fake_hw, leader))
 		return false;
-	list_for_each_entry(sibling, &leader->sibling_list, sibling_list) {
+	for_each_sibling_event(sibling, leader) {
 		if (!dsu_pmu_validate_event(event->pmu, &fake_hw, sibling))
 			return false;
 	}
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 628d7a7b9526..344e2083e941 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -311,7 +311,7 @@ validate_group(struct perf_event *event)
 	if (!validate_event(event->pmu, &fake_pmu, leader))
 		return -EINVAL;
 
-	list_for_each_entry(sibling, &leader->sibling_list, sibling_list) {
+	for_each_sibling_event(sibling, leader) {
 		if (!validate_event(event->pmu, &fake_pmu, sibling))
 			return -EINVAL;
 	}
diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c
index e3356087fd76..44df61397a38 100644
--- a/drivers/perf/hisilicon/hisi_uncore_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c
@@ -82,7 +82,7 @@ static bool hisi_validate_event_group(struct perf_event *event)
 			counters++;
 	}
 
-	list_for_each_entry(sibling, &event->group_leader->sibling_list, sibling_list) {
+	for_each_sibling_event(sibling, event->group_leader) {
 		if (is_software_event(sibling))
 			continue;
 		if (sibling->pmu != event->pmu)
diff --git a/drivers/perf/qcom_l2_pmu.c b/drivers/perf/qcom_l2_pmu.c
index 5e535a718965..842135cf35a3 100644
--- a/drivers/perf/qcom_l2_pmu.c
+++ b/drivers/perf/qcom_l2_pmu.c
@@ -534,14 +534,14 @@ static int l2_cache_event_init(struct perf_event *event)
 		return -EINVAL;
 	}
 
-	list_for_each_entry(sibling, &event->group_leader->sibling_list,
-			    sibling_list)
+	for_each_sibling_event(sibling, event->group_leader) {
 		if (sibling->pmu != event->pmu &&
 		    !is_software_event(sibling)) {
 			dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
 				 "Can't create mixed PMU group\n");
 			return -EINVAL;
 		}
+	}
 
 	cluster = get_cluster_pmu(l2cache_pmu, event->cpu);
 	if (!cluster) {
@@ -571,8 +571,7 @@ static int l2_cache_event_init(struct perf_event *event)
 		return -EINVAL;
 	}
 
-	list_for_each_entry(sibling, &event->group_leader->sibling_list,
-			    sibling_list) {
+	for_each_sibling_event(sibling, event->group_leader) {
 		if ((sibling != event) &&
 		    !is_software_event(sibling) &&
 		    (L2_EVT_GROUP(sibling->attr.config) ==
diff --git a/drivers/perf/qcom_l3_pmu.c b/drivers/perf/qcom_l3_pmu.c
index 5dedf4b1a552..2dc63d61f2ea 100644
--- a/drivers/perf/qcom_l3_pmu.c
+++ b/drivers/perf/qcom_l3_pmu.c
@@ -468,7 +468,7 @@ static bool qcom_l3_cache__validate_event_group(struct perf_event *event)
 	counters = event_num_counters(event);
 	counters += event_num_counters(leader);
 
-	list_for_each_entry(sibling, &leader->sibling_list, sibling_list) {
+	for_each_sibling_event(sibling, leader) {
 		if (is_software_event(sibling))
 			continue;
 		if (sibling->pmu != event->pmu)
diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c
index f1f4a56cab5e..6bdb1dad805f 100644
--- a/drivers/perf/xgene_pmu.c
+++ b/drivers/perf/xgene_pmu.c
@@ -949,11 +949,11 @@ static int xgene_perf_event_init(struct perf_event *event)
 			!is_software_event(event->group_leader))
 		return -EINVAL;
 
-	list_for_each_entry(sibling, &event->group_leader->sibling_list,
-			sibling_list)
+	for_each_sibling_event(sibling, event->group_leader) {
 		if (sibling->pmu != event->pmu &&
 				!is_software_event(sibling))
 			return -EINVAL;
+	}
 
 	return 0;
 }