Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
 "Misc fixes: a handful of AUX event handling related fixes, a Sparse
  fix and two ABI fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix missing static inline on perf_cgroup_switch()
  perf/core: Consistently fail fork on allocation failures
  perf/aux: Disallow aux_output for kernel events
  perf/core: Reattach a misplaced comment
  perf/aux: Fix the aux_output group inheritance fix
  perf/core: Disallow uncore-cgroup events

Author: torvalds

kernel/events/core.c

@@ -1031,7 +1031,7 @@ perf_cgroup_set_timestamp(struct task_struct *task,
 {
 }
 
-void
+static inline void
 perf_cgroup_switch(struct task_struct *task, struct task_struct *next)
 {
 }
@@ -10535,6 +10535,15 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
 		goto err_ns;
 	}
 
+	/*
+	 * Disallow uncore-cgroup events, they don't make sense as the cgroup will
+	 * be different on other CPUs in the uncore mask.
+	 */
+	if (pmu->task_ctx_nr == perf_invalid_context && cgroup_fd != -1) {
+		err = -EINVAL;
+		goto err_pmu;
+	}
+
 	if (event->attr.aux_output &&
 	    !(pmu->capabilities & PERF_PMU_CAP_AUX_OUTPUT)) {
 		err = -EOPNOTSUPP;
@@ -11323,8 +11332,11 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
 	int err;
 
 	/*
-	 * Get the target context (task or percpu):
+	 * Grouping is not supported for kernel events, neither is 'AUX',
+	 * make sure the caller's intentions are adjusted.
 	 */
+	if (attr->aux_output)
+		return ERR_PTR(-EINVAL);
 
 	event = perf_event_alloc(attr, cpu, task, NULL, NULL,
 				 overflow_handler, context, -1);
@@ -11336,6 +11348,9 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
 	/* Mark owner so we could distinguish it from user events. */
 	event->owner = TASK_TOMBSTONE;
 
+	/*
+	 * Get the target context (task or percpu):
+	 */
 	ctx = find_get_context(event->pmu, task, event);
 	if (IS_ERR(ctx)) {
 		err = PTR_ERR(ctx);
@@ -11787,7 +11802,7 @@ inherit_event(struct perf_event *parent_event,
 						   GFP_KERNEL);
 		if (!child_ctx->task_ctx_data) {
 			free_event(child_event);
-			return NULL;
+			return ERR_PTR(-ENOMEM);
 		}
 	}
 
@@ -11890,7 +11905,7 @@ static int inherit_group(struct perf_event *parent_event,
 		if (IS_ERR(child_ctr))
 			return PTR_ERR(child_ctr);
 
-		if (sub->aux_event == parent_event &&
+		if (sub->aux_event == parent_event && child_ctr &&
 		    !perf_get_aux_event(child_ctr, leader))
 			return -EINVAL;
 	}