From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 6 May 2014 07:59:34 +0000 (+0200)
Subject: perf: Ensure consistent inherit state in groups
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=1f4ee5038f0c1ef95f8e6d47ad6623e006b5bce1;p=deliverable%2Flinux.git

perf: Ensure consistent inherit state in groups

Make sure all events in a group have the same inherit state. It was
possible for group leaders to have inherit set while sibling events
would not have inherit set.

In this case we'd still inherit the siblings, leading to some
non-fatal weirdness.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-r32tt8yldvic3jlcghd3g35u@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 09866a330af8..1de0d709f69f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7081,20 +7081,26 @@ SYSCALL_DEFINE5(perf_event_open,
 		}
 	}
 
+	if (task && group_leader &&
+	    group_leader->attr.inherit != attr.inherit) {
+		err = -EINVAL;
+		goto err_task;
+	}
+
 	get_online_cpus();
 
 	event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
 				 NULL, NULL);
 	if (IS_ERR(event)) {
 		err = PTR_ERR(event);
-		goto err_task;
+		goto err_cpus;
 	}
 
 	if (flags & PERF_FLAG_PID_CGROUP) {
 		err = perf_cgroup_connect(pid, event, &attr, group_leader);
 		if (err) {
 			__free_event(event);
-			goto err_task;
+			goto err_cpus;
 		}
 	}
 
@@ -7256,8 +7262,9 @@ err_context:
 	put_ctx(ctx);
 err_alloc:
 	free_event(event);
-err_task:
+err_cpus:
 	put_online_cpus();
+err_task:
 	if (task)
 		put_task_struct(task);
 err_group_fd: